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Annotation of src/usr.bin/ssh/packet.c, Revision 1.313

1.313   ! djm         1: /* $OpenBSD: packet.c,v 1.312 2023/08/28 03:31:16 djm Exp $ */
1.1       deraadt     2: /*
1.15      deraadt     3:  * Author: Tatu Ylonen <ylo@cs.hut.fi>
                      4:  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
                      5:  *                    All rights reserved
1.35      deraadt     6:  * This file contains code implementing the packet protocol and communication
                      7:  * with the other side.  This same code is used both on client and server side.
1.29      markus      8:  *
1.35      deraadt     9:  * As far as I am concerned, the code I have written for this software
                     10:  * can be used freely for any purpose.  Any derived versions of this
                     11:  * software must be clearly marked as such, and if the derived work is
                     12:  * incompatible with the protocol description in the RFC file, it must be
                     13:  * called by a name other than "ssh" or "Secure Shell".
1.29      markus     14:  *
1.25      markus     15:  *
                     16:  * SSH2 packet format added by Markus Friedl.
1.69      markus     17:  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
1.25      markus     18:  *
1.35      deraadt    19:  * Redistribution and use in source and binary forms, with or without
                     20:  * modification, are permitted provided that the following conditions
                     21:  * are met:
                     22:  * 1. Redistributions of source code must retain the above copyright
                     23:  *    notice, this list of conditions and the following disclaimer.
                     24:  * 2. Redistributions in binary form must reproduce the above copyright
                     25:  *    notice, this list of conditions and the following disclaimer in the
                     26:  *    documentation and/or other materials provided with the distribution.
                     27:  *
                     28:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
                     29:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
                     30:  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
                     31:  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
                     32:  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
                     33:  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
                     34:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
                     35:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
                     36:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
                     37:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15      deraadt    38:  */
1.1       deraadt    39:
1.142     deraadt    40: #include <sys/types.h>
1.105     markus     41: #include <sys/queue.h>
1.132     stevesk    42: #include <sys/socket.h>
1.138     stevesk    43: #include <sys/time.h>
1.132     stevesk    44: #include <netinet/in.h>
1.121     stevesk    45: #include <netinet/ip.h>
1.134     stevesk    46:
1.135     stevesk    47: #include <errno.h>
1.230     djm        48: #include <netdb.h>
1.134     stevesk    49: #include <stdarg.h>
1.141     stevesk    50: #include <stdio.h>
1.140     stevesk    51: #include <stdlib.h>
1.137     stevesk    52: #include <string.h>
1.136     stevesk    53: #include <unistd.h>
1.203     deraadt    54: #include <limits.h>
1.278     djm        55: #include <poll.h>
1.142     deraadt    56: #include <signal.h>
1.184     dtucker    57: #include <time.h>
1.1       deraadt    58:
1.288     dtucker    59: #ifdef WITH_ZLIB
1.201     markus     60: #include <zlib.h>
1.288     dtucker    61: #endif
1.201     markus     62:
1.1       deraadt    63: #include "xmalloc.h"
1.25      markus     64: #include "compat.h"
                     65: #include "ssh2.h"
1.37      markus     66: #include "cipher.h"
1.201     markus     67: #include "sshkey.h"
1.25      markus     68: #include "kex.h"
1.200     markus     69: #include "digest.h"
1.50      markus     70: #include "mac.h"
1.46      markus     71: #include "log.h"
                     72: #include "canohost.h"
1.87      stevesk    73: #include "misc.h"
1.198     millert    74: #include "channels.h"
1.95      markus     75: #include "ssh.h"
1.201     markus     76: #include "packet.h"
1.197     djm        77: #include "ssherr.h"
1.201     markus     78: #include "sshbuf.h"
1.25      markus     79:
                     80: #ifdef PACKET_DEBUG
                     81: #define DBG(x) x
                     82: #else
                     83: #define DBG(x)
                     84: #endif
                     85:
1.159     markus     86: #define PACKET_MAX_SIZE (256 * 1024)
                     87:
1.161     andreas    88: struct packet_state {
                     89:        u_int32_t seqnr;
                     90:        u_int32_t packets;
                     91:        u_int64_t blocks;
                     92:        u_int64_t bytes;
                     93: };
                     94:
                     95: struct packet {
                     96:        TAILQ_ENTRY(packet) next;
                     97:        u_char type;
1.201     markus     98:        struct sshbuf *payload;
1.161     andreas    99: };
                    100:
                    101: struct session_state {
                    102:        /*
                    103:         * This variable contains the file descriptors used for
                    104:         * communicating with the other side.  connection_in is used for
                    105:         * reading; connection_out for writing.  These can be the same
                    106:         * descriptor, in which case it is assumed to be a socket.
                    107:         */
                    108:        int connection_in;
                    109:        int connection_out;
                    110:
                    111:        /* Protocol flags for the remote side. */
                    112:        u_int remote_protocol_flags;
1.1       deraadt   113:
1.161     andreas   114:        /* Encryption context for receiving data.  Only used for decryption. */
1.235     djm       115:        struct sshcipher_ctx *receive_context;
1.1       deraadt   116:
1.161     andreas   117:        /* Encryption context for sending data.  Only used for encryption. */
1.235     djm       118:        struct sshcipher_ctx *send_context;
1.14      markus    119:
1.161     andreas   120:        /* Buffer for raw input data from the socket. */
1.201     markus    121:        struct sshbuf *input;
1.1       deraadt   122:
1.161     andreas   123:        /* Buffer for raw output data going to the socket. */
1.201     markus    124:        struct sshbuf *output;
1.1       deraadt   125:
1.161     andreas   126:        /* Buffer for the partial outgoing packet being constructed. */
1.201     markus    127:        struct sshbuf *outgoing_packet;
1.1       deraadt   128:
1.161     andreas   129:        /* Buffer for the incoming packet currently being processed. */
1.201     markus    130:        struct sshbuf *incoming_packet;
1.1       deraadt   131:
1.161     andreas   132:        /* Scratch buffer for packet compression/decompression. */
1.201     markus    133:        struct sshbuf *compression_buffer;
                    134:
1.288     dtucker   135: #ifdef WITH_ZLIB
1.201     markus    136:        /* Incoming/outgoing compression dictionaries */
                    137:        z_stream compression_in_stream;
                    138:        z_stream compression_out_stream;
1.288     dtucker   139: #endif
1.201     markus    140:        int compression_in_started;
                    141:        int compression_out_started;
                    142:        int compression_in_failures;
                    143:        int compression_out_failures;
1.1       deraadt   144:
1.161     andreas   145:        /* default maximum packet size */
                    146:        u_int max_packet_size;
1.1       deraadt   147:
1.161     andreas   148:        /* Flag indicating whether this module has been initialized. */
                    149:        int initialized;
1.12      markus    150:
1.161     andreas   151:        /* Set to true if the connection is interactive. */
                    152:        int interactive_mode;
1.1       deraadt   153:
1.161     andreas   154:        /* Set to true if we are the server side. */
                    155:        int server_side;
1.1       deraadt   156:
1.161     andreas   157:        /* Set to true if we are authenticated. */
                    158:        int after_authentication;
1.118     markus    159:
1.161     andreas   160:        int keep_alive_timeouts;
1.118     markus    161:
1.161     andreas   162:        /* The maximum time that we will wait to send or receive a packet */
                    163:        int packet_timeout_ms;
1.151     dtucker   164:
1.161     andreas   165:        /* Session key information for Encryption and MAC */
1.201     markus    166:        struct newkeys *newkeys[MODE_MAX];
1.161     andreas   167:        struct packet_state p_read, p_send;
1.154     dtucker   168:
1.184     dtucker   169:        /* Volume-based rekeying */
1.224     dtucker   170:        u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105     markus    171:
1.184     dtucker   172:        /* Time-based rekeying */
1.208     markus    173:        u_int32_t rekey_interval;       /* how often in seconds */
1.184     dtucker   174:        time_t rekey_time;      /* time of last rekeying */
                    175:
1.161     andreas   176:        /* roundup current message to extra_pad bytes */
                    177:        u_char extra_pad;
1.95      markus    178:
1.161     andreas   179:        /* XXX discard incoming data after MAC error */
                    180:        u_int packet_discard;
1.234     markus    181:        size_t packet_discard_mac_already;
1.201     markus    182:        struct sshmac *packet_discard_mac;
1.71      markus    183:
1.161     andreas   184:        /* Used in packet_read_poll2() */
                    185:        u_int packlen;
1.159     markus    186:
1.165     andreas   187:        /* Used in packet_send2 */
                    188:        int rekeying;
                    189:
1.242     markus    190:        /* Used in ssh_packet_send_mux() */
                    191:        int mux;
                    192:
1.165     andreas   193:        /* Used in packet_set_interactive */
                    194:        int set_interactive_called;
                    195:
                    196:        /* Used in packet_set_maxsize */
                    197:        int set_maxsize_called;
                    198:
1.201     markus    199:        /* One-off warning about weak ciphers */
                    200:        int cipher_warning_done;
                    201:
1.243     djm       202:        /* Hook for fuzzing inbound packets */
                    203:        ssh_packet_hook_fn *hook_in;
                    204:        void *hook_in_ctx;
                    205:
1.161     andreas   206:        TAILQ_HEAD(, packet) outgoing;
1.105     markus    207: };
1.161     andreas   208:
1.201     markus    209: struct ssh *
                    210: ssh_alloc_session_state(void)
1.161     andreas   211: {
1.201     markus    212:        struct ssh *ssh = NULL;
                    213:        struct session_state *state = NULL;
1.161     andreas   214:
1.201     markus    215:        if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
                    216:            (state = calloc(1, sizeof(*state))) == NULL ||
1.278     djm       217:            (ssh->kex = kex_new()) == NULL ||
1.201     markus    218:            (state->input = sshbuf_new()) == NULL ||
                    219:            (state->output = sshbuf_new()) == NULL ||
                    220:            (state->outgoing_packet = sshbuf_new()) == NULL ||
                    221:            (state->incoming_packet = sshbuf_new()) == NULL)
                    222:                goto fail;
                    223:        TAILQ_INIT(&state->outgoing);
1.202     markus    224:        TAILQ_INIT(&ssh->private_keys);
                    225:        TAILQ_INIT(&ssh->public_keys);
1.201     markus    226:        state->connection_in = -1;
                    227:        state->connection_out = -1;
                    228:        state->max_packet_size = 32768;
                    229:        state->packet_timeout_ms = -1;
                    230:        state->p_send.packets = state->p_read.packets = 0;
                    231:        state->initialized = 1;
                    232:        /*
                    233:         * ssh_packet_send2() needs to queue packets until
                    234:         * we've done the initial key exchange.
                    235:         */
                    236:        state->rekeying = 1;
                    237:        ssh->state = state;
                    238:        return ssh;
                    239:  fail:
1.278     djm       240:        if (ssh) {
                    241:                kex_free(ssh->kex);
                    242:                free(ssh);
                    243:        }
1.201     markus    244:        if (state) {
                    245:                sshbuf_free(state->input);
                    246:                sshbuf_free(state->output);
                    247:                sshbuf_free(state->incoming_packet);
                    248:                sshbuf_free(state->outgoing_packet);
                    249:                free(state);
                    250:        }
                    251:        return NULL;
1.161     andreas   252: }
1.105     markus    253:
1.243     djm       254: void
                    255: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
                    256: {
                    257:        ssh->state->hook_in = hook;
                    258:        ssh->state->hook_in_ctx = ctx;
                    259: }
                    260:
1.228     djm       261: /* Returns nonzero if rekeying is in progress */
                    262: int
                    263: ssh_packet_is_rekeying(struct ssh *ssh)
                    264: {
1.292     markus    265:        return ssh->state->rekeying ||
                    266:            (ssh->kex != NULL && ssh->kex->done == 0);
1.228     djm       267: }
                    268:
1.16      markus    269: /*
1.253     naddy     270:  * Sets the descriptors used for communication.
1.16      markus    271:  */
1.201     markus    272: struct ssh *
                    273: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1       deraadt   274: {
1.201     markus    275:        struct session_state *state;
                    276:        const struct sshcipher *none = cipher_by_name("none");
1.197     djm       277:        int r;
1.97      deraadt   278:
1.205     djm       279:        if (none == NULL) {
1.297     djm       280:                error_f("cannot load cipher 'none'");
1.205     djm       281:                return NULL;
                    282:        }
1.201     markus    283:        if (ssh == NULL)
                    284:                ssh = ssh_alloc_session_state();
1.205     djm       285:        if (ssh == NULL) {
1.297     djm       286:                error_f("could not allocate state");
1.205     djm       287:                return NULL;
                    288:        }
1.201     markus    289:        state = ssh->state;
                    290:        state->connection_in = fd_in;
                    291:        state->connection_out = fd_out;
                    292:        if ((r = cipher_init(&state->send_context, none,
1.197     djm       293:            (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201     markus    294:            (r = cipher_init(&state->receive_context, none,
1.205     djm       295:            (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
1.297     djm       296:                error_fr(r, "cipher_init failed");
1.230     djm       297:                free(ssh); /* XXX need ssh_free_session_state? */
1.205     djm       298:                return NULL;
                    299:        }
1.201     markus    300:        state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207     djm       301:        /*
                    302:         * Cache the IP address of the remote connection for use in error
                    303:         * messages that might be generated after the connection has closed.
                    304:         */
                    305:        (void)ssh_remote_ipaddr(ssh);
1.201     markus    306:        return ssh;
1.1       deraadt   307: }
                    308:
1.154     dtucker   309: void
1.201     markus    310: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154     dtucker   311: {
1.201     markus    312:        struct session_state *state = ssh->state;
                    313:
1.174     djm       314:        if (timeout <= 0 || count <= 0) {
1.201     markus    315:                state->packet_timeout_ms = -1;
1.154     dtucker   316:                return;
                    317:        }
                    318:        if ((INT_MAX / 1000) / count < timeout)
1.201     markus    319:                state->packet_timeout_ms = INT_MAX;
1.154     dtucker   320:        else
1.201     markus    321:                state->packet_timeout_ms = timeout * count * 1000;
1.154     dtucker   322: }
                    323:
1.242     markus    324: void
                    325: ssh_packet_set_mux(struct ssh *ssh)
                    326: {
                    327:        ssh->state->mux = 1;
                    328:        ssh->state->rekeying = 0;
1.292     markus    329:        kex_free(ssh->kex);
                    330:        ssh->kex = NULL;
1.242     markus    331: }
                    332:
                    333: int
                    334: ssh_packet_get_mux(struct ssh *ssh)
                    335: {
                    336:        return ssh->state->mux;
                    337: }
                    338:
1.201     markus    339: int
1.245     djm       340: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
                    341: {
                    342:        va_list args;
                    343:        int r;
                    344:
                    345:        free(ssh->log_preamble);
                    346:        if (fmt == NULL)
                    347:                ssh->log_preamble = NULL;
                    348:        else {
                    349:                va_start(args, fmt);
                    350:                r = vasprintf(&ssh->log_preamble, fmt, args);
                    351:                va_end(args);
                    352:                if (r < 0 || ssh->log_preamble == NULL)
                    353:                        return SSH_ERR_ALLOC_FAIL;
                    354:        }
                    355:        return 0;
                    356: }
                    357:
                    358: int
1.201     markus    359: ssh_packet_stop_discard(struct ssh *ssh)
1.159     markus    360: {
1.201     markus    361:        struct session_state *state = ssh->state;
                    362:        int r;
                    363:
                    364:        if (state->packet_discard_mac) {
1.159     markus    365:                char buf[1024];
1.234     markus    366:                size_t dlen = PACKET_MAX_SIZE;
1.201     markus    367:
1.234     markus    368:                if (dlen > state->packet_discard_mac_already)
                    369:                        dlen -= state->packet_discard_mac_already;
1.159     markus    370:                memset(buf, 'a', sizeof(buf));
1.234     markus    371:                while (sshbuf_len(state->incoming_packet) < dlen)
1.201     markus    372:                        if ((r = sshbuf_put(state->incoming_packet, buf,
                    373:                            sizeof(buf))) != 0)
                    374:                                return r;
                    375:                (void) mac_compute(state->packet_discard_mac,
                    376:                    state->p_read.seqnr,
1.234     markus    377:                    sshbuf_ptr(state->incoming_packet), dlen,
1.201     markus    378:                    NULL, 0);
1.159     markus    379:        }
1.220     djm       380:        logit("Finished discarding for %.200s port %d",
                    381:            ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201     markus    382:        return SSH_ERR_MAC_INVALID;
1.159     markus    383: }
                    384:
1.201     markus    385: static int
                    386: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234     markus    387:     struct sshmac *mac, size_t mac_already, u_int discard)
1.159     markus    388: {
1.201     markus    389:        struct session_state *state = ssh->state;
                    390:        int r;
                    391:
                    392:        if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
                    393:                if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
                    394:                        return r;
                    395:                return SSH_ERR_MAC_INVALID;
                    396:        }
1.234     markus    397:        /*
                    398:         * Record number of bytes over which the mac has already
                    399:         * been computed in order to minimize timing attacks.
                    400:         */
                    401:        if (mac && mac->enabled) {
1.201     markus    402:                state->packet_discard_mac = mac;
1.234     markus    403:                state->packet_discard_mac_already = mac_already;
                    404:        }
                    405:        if (sshbuf_len(state->input) >= discard)
                    406:                return ssh_packet_stop_discard(ssh);
1.201     markus    407:        state->packet_discard = discard - sshbuf_len(state->input);
                    408:        return 0;
1.159     markus    409: }
                    410:
1.19      markus    411: /* Returns 1 if remote host is connected via socket, 0 if not. */
                    412:
                    413: int
1.201     markus    414: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19      markus    415: {
1.271     djm       416:        struct session_state *state;
1.19      markus    417:        struct sockaddr_storage from, to;
                    418:        socklen_t fromlen, tolen;
                    419:
1.271     djm       420:        if (ssh == NULL || ssh->state == NULL)
                    421:                return 0;
                    422:
                    423:        state = ssh->state;
1.230     djm       424:        if (state->connection_in == -1 || state->connection_out == -1)
                    425:                return 0;
1.19      markus    426:        /* filedescriptors in and out are the same, so it's a socket */
1.201     markus    427:        if (state->connection_in == state->connection_out)
1.19      markus    428:                return 1;
                    429:        fromlen = sizeof(from);
                    430:        memset(&from, 0, sizeof(from));
1.201     markus    431:        if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.286     deraadt   432:            &fromlen) == -1)
1.19      markus    433:                return 0;
                    434:        tolen = sizeof(to);
                    435:        memset(&to, 0, sizeof(to));
1.201     markus    436:        if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.286     deraadt   437:            &tolen) == -1)
1.19      markus    438:                return 0;
                    439:        if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
                    440:                return 0;
                    441:        if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
                    442:                return 0;
                    443:        return 1;
                    444: }
                    445:
1.91      markus    446: void
1.201     markus    447: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91      markus    448: {
1.201     markus    449:        if (ibytes)
                    450:                *ibytes = ssh->state->p_read.bytes;
                    451:        if (obytes)
                    452:                *obytes = ssh->state->p_send.bytes;
1.91      markus    453: }
1.125     deraadt   454:
1.91      markus    455: int
1.201     markus    456: ssh_packet_connection_af(struct ssh *ssh)
1.19      markus    457: {
1.298     djm       458:        return get_sock_af(ssh->state->connection_out);
1.19      markus    459: }
                    460:
1.1       deraadt   461: /* Sets the connection into non-blocking mode. */
                    462:
1.2       provos    463: void
1.201     markus    464: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1       deraadt   465: {
1.14      markus    466:        /* Set the socket into non-blocking mode. */
1.201     markus    467:        set_nonblock(ssh->state->connection_in);
1.14      markus    468:
1.201     markus    469:        if (ssh->state->connection_out != ssh->state->connection_in)
                    470:                set_nonblock(ssh->state->connection_out);
1.1       deraadt   471: }
                    472:
                    473: /* Returns the socket used for reading. */
                    474:
1.2       provos    475: int
1.201     markus    476: ssh_packet_get_connection_in(struct ssh *ssh)
1.1       deraadt   477: {
1.201     markus    478:        return ssh->state->connection_in;
1.1       deraadt   479: }
                    480:
                    481: /* Returns the descriptor used for writing. */
                    482:
1.2       provos    483: int
1.201     markus    484: ssh_packet_get_connection_out(struct ssh *ssh)
1.1       deraadt   485: {
1.201     markus    486:        return ssh->state->connection_out;
                    487: }
                    488:
                    489: /*
                    490:  * Returns the IP-address of the remote host as a string.  The returned
                    491:  * string must not be freed.
                    492:  */
                    493:
                    494: const char *
                    495: ssh_remote_ipaddr(struct ssh *ssh)
                    496: {
1.271     djm       497:        int sock;
1.220     djm       498:
1.201     markus    499:        /* Check whether we have cached the ipaddr. */
1.220     djm       500:        if (ssh->remote_ipaddr == NULL) {
                    501:                if (ssh_packet_connection_is_on_socket(ssh)) {
1.271     djm       502:                        sock = ssh->state->connection_in;
1.220     djm       503:                        ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230     djm       504:                        ssh->remote_port = get_peer_port(sock);
                    505:                        ssh->local_ipaddr = get_local_ipaddr(sock);
                    506:                        ssh->local_port = get_local_port(sock);
1.220     djm       507:                } else {
1.287     tobhe     508:                        ssh->remote_ipaddr = xstrdup("UNKNOWN");
1.230     djm       509:                        ssh->remote_port = 65535;
1.287     tobhe     510:                        ssh->local_ipaddr = xstrdup("UNKNOWN");
1.230     djm       511:                        ssh->local_port = 65535;
1.220     djm       512:                }
                    513:        }
1.201     markus    514:        return ssh->remote_ipaddr;
1.1       deraadt   515: }
                    516:
1.220     djm       517: /* Returns the port number of the remote host. */
                    518:
                    519: int
                    520: ssh_remote_port(struct ssh *ssh)
                    521: {
                    522:        (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
                    523:        return ssh->remote_port;
1.230     djm       524: }
                    525:
                    526: /*
                    527:  * Returns the IP-address of the local host as a string.  The returned
                    528:  * string must not be freed.
                    529:  */
                    530:
                    531: const char *
                    532: ssh_local_ipaddr(struct ssh *ssh)
                    533: {
                    534:        (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
                    535:        return ssh->local_ipaddr;
                    536: }
                    537:
                    538: /* Returns the port number of the local host. */
                    539:
                    540: int
                    541: ssh_local_port(struct ssh *ssh)
                    542: {
                    543:        (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
                    544:        return ssh->local_port;
1.266     djm       545: }
                    546:
                    547: /* Returns the routing domain of the input socket, or NULL if unavailable */
                    548: const char *
                    549: ssh_packet_rdomain_in(struct ssh *ssh)
                    550: {
                    551:        if (ssh->rdomain_in != NULL)
                    552:                return ssh->rdomain_in;
                    553:        if (!ssh_packet_connection_is_on_socket(ssh))
                    554:                return NULL;
                    555:        ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
                    556:        return ssh->rdomain_in;
1.220     djm       557: }
                    558:
1.1       deraadt   559: /* Closes the connection and clears and frees internal data structures. */
                    560:
1.257     markus    561: static void
                    562: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1       deraadt   563: {
1.201     markus    564:        struct session_state *state = ssh->state;
                    565:        u_int mode;
                    566:
                    567:        if (!state->initialized)
1.14      markus    568:                return;
1.201     markus    569:        state->initialized = 0;
1.257     markus    570:        if (do_close) {
                    571:                if (state->connection_in == state->connection_out) {
                    572:                        close(state->connection_out);
                    573:                } else {
                    574:                        close(state->connection_in);
                    575:                        close(state->connection_out);
                    576:                }
1.14      markus    577:        }
1.201     markus    578:        sshbuf_free(state->input);
                    579:        sshbuf_free(state->output);
                    580:        sshbuf_free(state->outgoing_packet);
                    581:        sshbuf_free(state->incoming_packet);
1.257     markus    582:        for (mode = 0; mode < MODE_MAX; mode++) {
                    583:                kex_free_newkeys(state->newkeys[mode]); /* current keys */
                    584:                state->newkeys[mode] = NULL;
                    585:                ssh_clear_newkeys(ssh, mode);           /* next keys */
                    586:        }
1.288     dtucker   587: #ifdef WITH_ZLIB
1.289     dtucker   588:        /* compression state is in shared mem, so we can only release it once */
1.257     markus    589:        if (do_close && state->compression_buffer) {
1.201     markus    590:                sshbuf_free(state->compression_buffer);
                    591:                if (state->compression_out_started) {
                    592:                        z_streamp stream = &state->compression_out_stream;
                    593:                        debug("compress outgoing: "
                    594:                            "raw data %llu, compressed %llu, factor %.2f",
                    595:                                (unsigned long long)stream->total_in,
                    596:                                (unsigned long long)stream->total_out,
                    597:                                stream->total_in == 0 ? 0.0 :
                    598:                                (double) stream->total_out / stream->total_in);
                    599:                        if (state->compression_out_failures == 0)
                    600:                                deflateEnd(stream);
                    601:                }
                    602:                if (state->compression_in_started) {
1.260     dtucker   603:                        z_streamp stream = &state->compression_in_stream;
1.201     markus    604:                        debug("compress incoming: "
                    605:                            "raw data %llu, compressed %llu, factor %.2f",
                    606:                            (unsigned long long)stream->total_out,
                    607:                            (unsigned long long)stream->total_in,
                    608:                            stream->total_out == 0 ? 0.0 :
                    609:                            (double) stream->total_in / stream->total_out);
                    610:                        if (state->compression_in_failures == 0)
                    611:                                inflateEnd(stream);
                    612:                }
1.14      markus    613:        }
1.288     dtucker   614: #endif /* WITH_ZLIB */
1.235     djm       615:        cipher_free(state->send_context);
                    616:        cipher_free(state->receive_context);
                    617:        state->send_context = state->receive_context = NULL;
1.257     markus    618:        if (do_close) {
1.277     djm       619:                free(ssh->local_ipaddr);
                    620:                ssh->local_ipaddr = NULL;
1.257     markus    621:                free(ssh->remote_ipaddr);
                    622:                ssh->remote_ipaddr = NULL;
                    623:                free(ssh->state);
                    624:                ssh->state = NULL;
1.295     markus    625:                kex_free(ssh->kex);
                    626:                ssh->kex = NULL;
1.257     markus    627:        }
                    628: }
                    629:
                    630: void
                    631: ssh_packet_close(struct ssh *ssh)
                    632: {
                    633:        ssh_packet_close_internal(ssh, 1);
                    634: }
                    635:
                    636: void
                    637: ssh_packet_clear_keys(struct ssh *ssh)
                    638: {
                    639:        ssh_packet_close_internal(ssh, 0);
1.1       deraadt   640: }
                    641:
                    642: /* Sets remote side protocol flags. */
                    643:
1.2       provos    644: void
1.201     markus    645: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1       deraadt   646: {
1.201     markus    647:        ssh->state->remote_protocol_flags = protocol_flags;
1.1       deraadt   648: }
                    649:
                    650: /* Returns the remote protocol flags set earlier by the above function. */
                    651:
1.40      markus    652: u_int
1.201     markus    653: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1       deraadt   654: {
1.201     markus    655:        return ssh->state->remote_protocol_flags;
1.1       deraadt   656: }
                    657:
1.16      markus    658: /*
                    659:  * Starts packet compression from the next packet on in both directions.
                    660:  * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
                    661:  */
1.1       deraadt   662:
1.201     markus    663: static int
                    664: ssh_packet_init_compression(struct ssh *ssh)
1.60      markus    665: {
1.201     markus    666:        if (!ssh->state->compression_buffer &&
1.300     djm       667:            ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
1.201     markus    668:                return SSH_ERR_ALLOC_FAIL;
                    669:        return 0;
1.60      markus    670: }
                    671:
1.288     dtucker   672: #ifdef WITH_ZLIB
1.201     markus    673: static int
                    674: start_compression_out(struct ssh *ssh, int level)
1.1       deraadt   675: {
1.201     markus    676:        if (level < 1 || level > 9)
                    677:                return SSH_ERR_INVALID_ARGUMENT;
                    678:        debug("Enabling compression at level %d.", level);
                    679:        if (ssh->state->compression_out_started == 1)
                    680:                deflateEnd(&ssh->state->compression_out_stream);
                    681:        switch (deflateInit(&ssh->state->compression_out_stream, level)) {
                    682:        case Z_OK:
                    683:                ssh->state->compression_out_started = 1;
                    684:                break;
                    685:        case Z_MEM_ERROR:
                    686:                return SSH_ERR_ALLOC_FAIL;
                    687:        default:
                    688:                return SSH_ERR_INTERNAL_ERROR;
                    689:        }
                    690:        return 0;
1.1       deraadt   691: }
                    692:
1.201     markus    693: static int
                    694: start_compression_in(struct ssh *ssh)
                    695: {
                    696:        if (ssh->state->compression_in_started == 1)
                    697:                inflateEnd(&ssh->state->compression_in_stream);
                    698:        switch (inflateInit(&ssh->state->compression_in_stream)) {
                    699:        case Z_OK:
                    700:                ssh->state->compression_in_started = 1;
                    701:                break;
                    702:        case Z_MEM_ERROR:
                    703:                return SSH_ERR_ALLOC_FAIL;
                    704:        default:
                    705:                return SSH_ERR_INTERNAL_ERROR;
                    706:        }
                    707:        return 0;
1.95      markus    708: }
                    709:
1.201     markus    710: /* XXX remove need for separate compression buffer */
                    711: static int
                    712: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95      markus    713: {
1.201     markus    714:        u_char buf[4096];
                    715:        int r, status;
                    716:
                    717:        if (ssh->state->compression_out_started != 1)
                    718:                return SSH_ERR_INTERNAL_ERROR;
                    719:
                    720:        /* This case is not handled below. */
                    721:        if (sshbuf_len(in) == 0)
                    722:                return 0;
                    723:
                    724:        /* Input is the contents of the input buffer. */
                    725:        if ((ssh->state->compression_out_stream.next_in =
                    726:            sshbuf_mutable_ptr(in)) == NULL)
                    727:                return SSH_ERR_INTERNAL_ERROR;
                    728:        ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
                    729:
                    730:        /* Loop compressing until deflate() returns with avail_out != 0. */
                    731:        do {
                    732:                /* Set up fixed-size output buffer. */
                    733:                ssh->state->compression_out_stream.next_out = buf;
                    734:                ssh->state->compression_out_stream.avail_out = sizeof(buf);
                    735:
                    736:                /* Compress as much data into the buffer as possible. */
                    737:                status = deflate(&ssh->state->compression_out_stream,
                    738:                    Z_PARTIAL_FLUSH);
                    739:                switch (status) {
                    740:                case Z_MEM_ERROR:
                    741:                        return SSH_ERR_ALLOC_FAIL;
                    742:                case Z_OK:
                    743:                        /* Append compressed data to output_buffer. */
                    744:                        if ((r = sshbuf_put(out, buf, sizeof(buf) -
                    745:                            ssh->state->compression_out_stream.avail_out)) != 0)
                    746:                                return r;
                    747:                        break;
                    748:                case Z_STREAM_ERROR:
                    749:                default:
                    750:                        ssh->state->compression_out_failures++;
                    751:                        return SSH_ERR_INVALID_FORMAT;
                    752:                }
                    753:        } while (ssh->state->compression_out_stream.avail_out == 0);
                    754:        return 0;
1.1       deraadt   755: }
                    756:
1.201     markus    757: static int
                    758: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1       deraadt   759: {
1.201     markus    760:        u_char buf[4096];
                    761:        int r, status;
1.1       deraadt   762:
1.201     markus    763:        if (ssh->state->compression_in_started != 1)
                    764:                return SSH_ERR_INTERNAL_ERROR;
1.25      markus    765:
1.201     markus    766:        if ((ssh->state->compression_in_stream.next_in =
                    767:            sshbuf_mutable_ptr(in)) == NULL)
                    768:                return SSH_ERR_INTERNAL_ERROR;
                    769:        ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97      deraadt   770:
1.201     markus    771:        for (;;) {
                    772:                /* Set up fixed-size output buffer. */
                    773:                ssh->state->compression_in_stream.next_out = buf;
                    774:                ssh->state->compression_in_stream.avail_out = sizeof(buf);
                    775:
                    776:                status = inflate(&ssh->state->compression_in_stream,
1.305     djm       777:                    Z_SYNC_FLUSH);
1.201     markus    778:                switch (status) {
                    779:                case Z_OK:
                    780:                        if ((r = sshbuf_put(out, buf, sizeof(buf) -
                    781:                            ssh->state->compression_in_stream.avail_out)) != 0)
                    782:                                return r;
                    783:                        break;
                    784:                case Z_BUF_ERROR:
                    785:                        /*
                    786:                         * Comments in zlib.h say that we should keep calling
                    787:                         * inflate() until we get an error.  This appears to
                    788:                         * be the error that we get.
                    789:                         */
                    790:                        return 0;
                    791:                case Z_DATA_ERROR:
                    792:                        return SSH_ERR_INVALID_FORMAT;
                    793:                case Z_MEM_ERROR:
                    794:                        return SSH_ERR_ALLOC_FAIL;
                    795:                case Z_STREAM_ERROR:
                    796:                default:
                    797:                        ssh->state->compression_in_failures++;
                    798:                        return SSH_ERR_INTERNAL_ERROR;
                    799:                }
                    800:        }
                    801:        /* NOTREACHED */
1.170     djm       802: }
1.288     dtucker   803:
                    804: #else  /* WITH_ZLIB */
                    805:
                    806: static int
                    807: start_compression_out(struct ssh *ssh, int level)
                    808: {
                    809:        return SSH_ERR_INTERNAL_ERROR;
                    810: }
                    811:
                    812: static int
                    813: start_compression_in(struct ssh *ssh)
                    814: {
                    815:        return SSH_ERR_INTERNAL_ERROR;
                    816: }
                    817:
                    818: static int
                    819: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
                    820: {
                    821:        return SSH_ERR_INTERNAL_ERROR;
                    822: }
                    823:
                    824: static int
                    825: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
                    826: {
                    827:        return SSH_ERR_INTERNAL_ERROR;
                    828: }
                    829: #endif /* WITH_ZLIB */
1.170     djm       830:
1.257     markus    831: void
                    832: ssh_clear_newkeys(struct ssh *ssh, int mode)
                    833: {
1.259     djm       834:        if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257     markus    835:                kex_free_newkeys(ssh->kex->newkeys[mode]);
                    836:                ssh->kex->newkeys[mode] = NULL;
                    837:        }
                    838: }
                    839:
1.201     markus    840: int
                    841: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57      markus    842: {
1.201     markus    843:        struct session_state *state = ssh->state;
                    844:        struct sshenc *enc;
                    845:        struct sshmac *mac;
                    846:        struct sshcomp *comp;
1.235     djm       847:        struct sshcipher_ctx **ccp;
1.236     markus    848:        struct packet_state *ps;
1.105     markus    849:        u_int64_t *max_blocks;
1.259     djm       850:        const char *wmsg;
1.197     djm       851:        int r, crypt_type;
1.283     djm       852:        const char *dir = mode == MODE_OUT ? "out" : "in";
1.57      markus    853:
1.303     djm       854:        debug2_f("mode %d", mode);
1.57      markus    855:
1.88      markus    856:        if (mode == MODE_OUT) {
1.235     djm       857:                ccp = &state->send_context;
1.115     avsm      858:                crypt_type = CIPHER_ENCRYPT;
1.236     markus    859:                ps = &state->p_send;
1.201     markus    860:                max_blocks = &state->max_blocks_out;
1.88      markus    861:        } else {
1.235     djm       862:                ccp = &state->receive_context;
1.115     avsm      863:                crypt_type = CIPHER_DECRYPT;
1.236     markus    864:                ps = &state->p_read;
1.201     markus    865:                max_blocks = &state->max_blocks_in;
1.88      markus    866:        }
1.201     markus    867:        if (state->newkeys[mode] != NULL) {
1.297     djm       868:                debug_f("rekeying %s, input %llu bytes %llu blocks, "
1.300     djm       869:                    "output %llu bytes %llu blocks", dir,
                    870:                    (unsigned long long)state->p_read.bytes,
                    871:                    (unsigned long long)state->p_read.blocks,
                    872:                    (unsigned long long)state->p_send.bytes,
                    873:                    (unsigned long long)state->p_send.blocks);
1.257     markus    874:                kex_free_newkeys(state->newkeys[mode]);
                    875:                state->newkeys[mode] = NULL;
1.57      markus    876:        }
1.236     markus    877:        /* note that both bytes and the seqnr are not reset */
                    878:        ps->packets = ps->blocks = 0;
1.201     markus    879:        /* move newkeys from kex to state */
                    880:        if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
                    881:                return SSH_ERR_INTERNAL_ERROR;
                    882:        ssh->kex->newkeys[mode] = NULL;
                    883:        enc  = &state->newkeys[mode]->enc;
                    884:        mac  = &state->newkeys[mode]->mac;
                    885:        comp = &state->newkeys[mode]->comp;
                    886:        if (cipher_authlen(enc->cipher) == 0) {
                    887:                if ((r = mac_init(mac)) != 0)
                    888:                        return r;
                    889:        }
                    890:        mac->enabled = 1;
1.303     djm       891:        DBG(debug_f("cipher_init: %s", dir));
1.279     djm       892:        cipher_free(*ccp);
                    893:        *ccp = NULL;
1.235     djm       894:        if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197     djm       895:            enc->iv, enc->iv_len, crypt_type)) != 0)
1.201     markus    896:                return r;
                    897:        if (!state->cipher_warning_done &&
1.235     djm       898:            (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201     markus    899:                error("Warning: %s", wmsg);
                    900:                state->cipher_warning_done = 1;
                    901:        }
1.91      markus    902:        /* Deleting the keys does not gain extra security */
1.192     djm       903:        /* explicit_bzero(enc->iv,  enc->block_size);
                    904:           explicit_bzero(enc->key, enc->key_len);
                    905:           explicit_bzero(mac->key, mac->key_len); */
1.275     sf        906:        if ((comp->type == COMP_ZLIB ||
                    907:            (comp->type == COMP_DELAYED &&
1.300     djm       908:            state->after_authentication)) && comp->enabled == 0) {
1.201     markus    909:                if ((r = ssh_packet_init_compression(ssh)) < 0)
                    910:                        return r;
                    911:                if (mode == MODE_OUT) {
                    912:                        if ((r = start_compression_out(ssh, 6)) != 0)
                    913:                                return r;
                    914:                } else {
                    915:                        if ((r = start_compression_in(ssh)) != 0)
                    916:                                return r;
                    917:                }
1.57      markus    918:                comp->enabled = 1;
                    919:        }
1.109     markus    920:        /*
                    921:         * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254     djm       922:         * so enforce a 1GB limit for small blocksizes.
1.261     dtucker   923:         * See RFC4344 section 3.2.
1.109     markus    924:         */
                    925:        if (enc->block_size >= 16)
                    926:                *max_blocks = (u_int64_t)1 << (enc->block_size*2);
                    927:        else
                    928:                *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201     markus    929:        if (state->rekey_limit)
1.237     deraadt   930:                *max_blocks = MINIMUM(*max_blocks,
1.201     markus    931:                    state->rekey_limit / enc->block_size);
1.283     djm       932:        debug("rekey %s after %llu blocks", dir,
                    933:            (unsigned long long)*max_blocks);
1.201     markus    934:        return 0;
1.57      markus    935: }
                    936:
1.228     djm       937: #define MAX_PACKETS    (1U<<31)
                    938: static int
                    939: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
                    940: {
                    941:        struct session_state *state = ssh->state;
                    942:        u_int32_t out_blocks;
                    943:
                    944:        /* XXX client can't cope with rekeying pre-auth */
                    945:        if (!state->after_authentication)
                    946:                return 0;
                    947:
                    948:        /* Haven't keyed yet or KEX in progress. */
1.278     djm       949:        if (ssh_packet_is_rekeying(ssh))
1.228     djm       950:                return 0;
                    951:
                    952:        /* Peer can't rekey */
                    953:        if (ssh->compat & SSH_BUG_NOREKEY)
                    954:                return 0;
                    955:
                    956:        /*
                    957:         * Permit one packet in or out per rekey - this allows us to
                    958:         * make progress when rekey limits are very small.
                    959:         */
                    960:        if (state->p_send.packets == 0 && state->p_read.packets == 0)
                    961:                return 0;
                    962:
                    963:        /* Time-based rekeying */
                    964:        if (state->rekey_interval != 0 &&
1.244     dtucker   965:            (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228     djm       966:                return 1;
                    967:
1.261     dtucker   968:        /*
1.308     djm       969:         * Always rekey when MAX_PACKETS sent in either direction
1.261     dtucker   970:         * As per RFC4344 section 3.1 we do this after 2^31 packets.
                    971:         */
1.228     djm       972:        if (state->p_send.packets > MAX_PACKETS ||
                    973:            state->p_read.packets > MAX_PACKETS)
                    974:                return 1;
                    975:
1.304     jsg       976:        /* Rekey after (cipher-specific) maximum blocks */
1.237     deraadt   977:        out_blocks = ROUNDUP(outbound_packet_len,
1.228     djm       978:            state->newkeys[MODE_OUT]->enc.block_size);
                    979:        return (state->max_blocks_out &&
                    980:            (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
                    981:            (state->max_blocks_in &&
                    982:            (state->p_read.blocks > state->max_blocks_in));
                    983: }
                    984:
1.301     djm       985: int
                    986: ssh_packet_check_rekey(struct ssh *ssh)
                    987: {
                    988:        if (!ssh_packet_need_rekeying(ssh, 0))
                    989:                return 0;
                    990:        debug3_f("rekex triggered");
                    991:        return kex_start_rekex(ssh);
                    992: }
                    993:
1.16      markus    994: /*
1.118     markus    995:  * Delayed compression for SSH2 is enabled after authentication:
1.143     dtucker   996:  * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118     markus    997:  * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
                    998:  */
1.201     markus    999: static int
                   1000: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118     markus   1001: {
1.201     markus   1002:        struct session_state *state = ssh->state;
                   1003:        struct sshcomp *comp = NULL;
                   1004:        int r, mode;
1.118     markus   1005:
                   1006:        /*
                   1007:         * Remember that we are past the authentication step, so rekeying
1.275     sf       1008:         * with COMP_DELAYED will turn on compression immediately.
1.118     markus   1009:         */
1.201     markus   1010:        state->after_authentication = 1;
1.118     markus   1011:        for (mode = 0; mode < MODE_MAX; mode++) {
1.145     markus   1012:                /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201     markus   1013:                if (state->newkeys[mode] == NULL)
1.145     markus   1014:                        continue;
1.201     markus   1015:                comp = &state->newkeys[mode]->comp;
1.275     sf       1016:                if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201     markus   1017:                        if ((r = ssh_packet_init_compression(ssh)) != 0)
                   1018:                                return r;
                   1019:                        if (mode == MODE_OUT) {
                   1020:                                if ((r = start_compression_out(ssh, 6)) != 0)
                   1021:                                        return r;
                   1022:                        } else {
                   1023:                                if ((r = start_compression_in(ssh)) != 0)
                   1024:                                        return r;
                   1025:                        }
1.118     markus   1026:                        comp->enabled = 1;
                   1027:                }
                   1028:        }
1.201     markus   1029:        return 0;
1.118     markus   1030: }
                   1031:
1.226     djm      1032: /* Used to mute debug logging for noisy packet types */
1.242     markus   1033: int
1.226     djm      1034: ssh_packet_log_type(u_char type)
                   1035: {
                   1036:        switch (type) {
1.311     djm      1037:        case SSH2_MSG_PING:
                   1038:        case SSH2_MSG_PONG:
1.226     djm      1039:        case SSH2_MSG_CHANNEL_DATA:
                   1040:        case SSH2_MSG_CHANNEL_EXTENDED_DATA:
                   1041:        case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
                   1042:                return 0;
                   1043:        default:
                   1044:                return 1;
                   1045:        }
                   1046: }
                   1047:
1.118     markus   1048: /*
1.25      markus   1049:  * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
                   1050:  */
1.201     markus   1051: int
                   1052: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25      markus   1053: {
1.201     markus   1054:        struct session_state *state = ssh->state;
1.200     markus   1055:        u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233     djm      1056:        u_char tmp, padlen, pad = 0;
1.201     markus   1057:        u_int authlen = 0, aadlen = 0;
                   1058:        u_int len;
                   1059:        struct sshenc *enc   = NULL;
                   1060:        struct sshmac *mac   = NULL;
                   1061:        struct sshcomp *comp = NULL;
                   1062:        int r, block_size;
                   1063:
                   1064:        if (state->newkeys[MODE_OUT] != NULL) {
                   1065:                enc  = &state->newkeys[MODE_OUT]->enc;
                   1066:                mac  = &state->newkeys[MODE_OUT]->mac;
                   1067:                comp = &state->newkeys[MODE_OUT]->comp;
1.180     markus   1068:                /* disable mac for authenticated encryption */
                   1069:                if ((authlen = cipher_authlen(enc->cipher)) != 0)
                   1070:                        mac = NULL;
1.25      markus   1071:        }
1.88      markus   1072:        block_size = enc ? enc->block_size : 8;
1.180     markus   1073:        aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25      markus   1074:
1.201     markus   1075:        type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226     djm      1076:        if (ssh_packet_log_type(type))
                   1077:                debug3("send packet: type %u", type);
1.25      markus   1078: #ifdef PACKET_DEBUG
                   1079:        fprintf(stderr, "plain:     ");
1.201     markus   1080:        sshbuf_dump(state->outgoing_packet, stderr);
1.25      markus   1081: #endif
                   1082:
                   1083:        if (comp && comp->enabled) {
1.201     markus   1084:                len = sshbuf_len(state->outgoing_packet);
1.25      markus   1085:                /* skip header, compress only payload */
1.201     markus   1086:                if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
                   1087:                        goto out;
                   1088:                sshbuf_reset(state->compression_buffer);
                   1089:                if ((r = compress_buffer(ssh, state->outgoing_packet,
                   1090:                    state->compression_buffer)) != 0)
                   1091:                        goto out;
                   1092:                sshbuf_reset(state->outgoing_packet);
                   1093:                if ((r = sshbuf_put(state->outgoing_packet,
                   1094:                    "\0\0\0\0\0", 5)) != 0 ||
                   1095:                    (r = sshbuf_putb(state->outgoing_packet,
                   1096:                    state->compression_buffer)) != 0)
                   1097:                        goto out;
                   1098:                DBG(debug("compression: raw %d compressed %zd", len,
                   1099:                    sshbuf_len(state->outgoing_packet)));
1.25      markus   1100:        }
                   1101:
                   1102:        /* sizeof (packet_len + pad_len + payload) */
1.201     markus   1103:        len = sshbuf_len(state->outgoing_packet);
1.25      markus   1104:
                   1105:        /*
                   1106:         * calc size of padding, alloc space, get random data,
                   1107:         * minimum padding is 4 bytes
                   1108:         */
1.178     markus   1109:        len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25      markus   1110:        padlen = block_size - (len % block_size);
                   1111:        if (padlen < 4)
                   1112:                padlen += block_size;
1.201     markus   1113:        if (state->extra_pad) {
1.233     djm      1114:                tmp = state->extra_pad;
1.201     markus   1115:                state->extra_pad =
1.237     deraadt  1116:                    ROUNDUP(state->extra_pad, block_size);
1.233     djm      1117:                /* check if roundup overflowed */
                   1118:                if (state->extra_pad < tmp)
                   1119:                        return SSH_ERR_INVALID_ARGUMENT;
                   1120:                tmp = (len + padlen) % state->extra_pad;
                   1121:                /* Check whether pad calculation below will underflow */
                   1122:                if (tmp > state->extra_pad)
                   1123:                        return SSH_ERR_INVALID_ARGUMENT;
                   1124:                pad = state->extra_pad - tmp;
1.297     djm      1125:                DBG(debug3_f("adding %d (len %d padlen %d extra_pad %d)",
                   1126:                    pad, len, padlen, state->extra_pad));
1.233     djm      1127:                tmp = padlen;
1.71      markus   1128:                padlen += pad;
1.233     djm      1129:                /* Check whether padlen calculation overflowed */
                   1130:                if (padlen < tmp)
                   1131:                        return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201     markus   1132:                state->extra_pad = 0;
1.71      markus   1133:        }
1.201     markus   1134:        if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
                   1135:                goto out;
1.235     djm      1136:        if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32      markus   1137:                /* random padding */
1.201     markus   1138:                arc4random_buf(cp, padlen);
1.32      markus   1139:        } else {
                   1140:                /* clear padding */
1.192     djm      1141:                explicit_bzero(cp, padlen);
1.25      markus   1142:        }
1.178     markus   1143:        /* sizeof (packet_len + pad_len + payload + padding) */
1.201     markus   1144:        len = sshbuf_len(state->outgoing_packet);
                   1145:        cp = sshbuf_mutable_ptr(state->outgoing_packet);
                   1146:        if (cp == NULL) {
                   1147:                r = SSH_ERR_INTERNAL_ERROR;
                   1148:                goto out;
                   1149:        }
1.25      markus   1150:        /* packet_length includes payload, padding and padding length field */
1.201     markus   1151:        POKE_U32(cp, len - 4);
1.89      markus   1152:        cp[4] = padlen;
1.178     markus   1153:        DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
                   1154:            len, padlen, aadlen));
1.25      markus   1155:
                   1156:        /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178     markus   1157:        if (mac && mac->enabled && !mac->etm) {
1.201     markus   1158:                if ((r = mac_compute(mac, state->p_send.seqnr,
                   1159:                    sshbuf_ptr(state->outgoing_packet), len,
1.200     markus   1160:                    macbuf, sizeof(macbuf))) != 0)
1.201     markus   1161:                        goto out;
                   1162:                DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25      markus   1163:        }
                   1164:        /* encrypt packet and append to output buffer. */
1.201     markus   1165:        if ((r = sshbuf_reserve(state->output,
                   1166:            sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
                   1167:                goto out;
1.235     djm      1168:        if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201     markus   1169:            sshbuf_ptr(state->outgoing_packet),
                   1170:            len - aadlen, aadlen, authlen)) != 0)
                   1171:                goto out;
1.25      markus   1172:        /* append unencrypted MAC */
1.178     markus   1173:        if (mac && mac->enabled) {
                   1174:                if (mac->etm) {
                   1175:                        /* EtM: compute mac over aadlen + cipher text */
1.201     markus   1176:                        if ((r = mac_compute(mac, state->p_send.seqnr,
                   1177:                            cp, len, macbuf, sizeof(macbuf))) != 0)
                   1178:                                goto out;
1.178     markus   1179:                        DBG(debug("done calc MAC(EtM) out #%d",
1.201     markus   1180:                            state->p_send.seqnr));
1.178     markus   1181:                }
1.201     markus   1182:                if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
                   1183:                        goto out;
1.178     markus   1184:        }
1.25      markus   1185: #ifdef PACKET_DEBUG
                   1186:        fprintf(stderr, "encrypted: ");
1.201     markus   1187:        sshbuf_dump(state->output, stderr);
1.25      markus   1188: #endif
1.29      markus   1189:        /* increment sequence number for outgoing packets */
1.313   ! djm      1190:        if (++state->p_send.seqnr == 0) {
        !          1191:                if ((ssh->kex->flags & KEX_INITIAL) != 0) {
        !          1192:                        ssh_packet_disconnect(ssh, "outgoing sequence number "
        !          1193:                            "wrapped during initial key exchange");
        !          1194:                }
1.106     itojun   1195:                logit("outgoing seqnr wraps around");
1.313   ! djm      1196:        }
1.201     markus   1197:        if (++state->p_send.packets == 0)
                   1198:                if (!(ssh->compat & SSH_BUG_NOREKEY))
                   1199:                        return SSH_ERR_NEED_REKEY;
                   1200:        state->p_send.blocks += len / block_size;
                   1201:        state->p_send.bytes += len;
                   1202:        sshbuf_reset(state->outgoing_packet);
1.25      markus   1203:
1.313   ! djm      1204:        if (type == SSH2_MSG_NEWKEYS && ssh->kex->kex_strict) {
        !          1205:                debug_f("resetting send seqnr %u", state->p_send.seqnr);
        !          1206:                state->p_send.seqnr = 0;
        !          1207:        }
        !          1208:
1.57      markus   1209:        if (type == SSH2_MSG_NEWKEYS)
1.201     markus   1210:                r = ssh_set_newkeys(ssh, MODE_OUT);
                   1211:        else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
                   1212:                r = ssh_packet_enable_delayed_compress(ssh);
                   1213:        else
                   1214:                r = 0;
                   1215:  out:
                   1216:        return r;
1.25      markus   1217: }
                   1218:
1.228     djm      1219: /* returns non-zero if the specified packet type is usec by KEX */
                   1220: static int
                   1221: ssh_packet_type_is_kex(u_char type)
                   1222: {
                   1223:        return
                   1224:            type >= SSH2_MSG_TRANSPORT_MIN &&
                   1225:            type <= SSH2_MSG_TRANSPORT_MAX &&
                   1226:            type != SSH2_MSG_SERVICE_REQUEST &&
                   1227:            type != SSH2_MSG_SERVICE_ACCEPT &&
                   1228:            type != SSH2_MSG_EXT_INFO;
                   1229: }
                   1230:
1.201     markus   1231: int
                   1232: ssh_packet_send2(struct ssh *ssh)
1.105     markus   1233: {
1.201     markus   1234:        struct session_state *state = ssh->state;
1.105     markus   1235:        struct packet *p;
1.201     markus   1236:        u_char type;
1.228     djm      1237:        int r, need_rekey;
1.105     markus   1238:
1.228     djm      1239:        if (sshbuf_len(state->outgoing_packet) < 6)
                   1240:                return SSH_ERR_INTERNAL_ERROR;
1.201     markus   1241:        type = sshbuf_ptr(state->outgoing_packet)[5];
1.228     djm      1242:        need_rekey = !ssh_packet_type_is_kex(type) &&
                   1243:            ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105     markus   1244:
1.228     djm      1245:        /*
                   1246:         * During rekeying we can only send key exchange messages.
                   1247:         * Queue everything else.
                   1248:         */
                   1249:        if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
                   1250:                if (need_rekey)
1.297     djm      1251:                        debug3_f("rekex triggered");
1.228     djm      1252:                debug("enqueue packet: %u", type);
                   1253:                p = calloc(1, sizeof(*p));
                   1254:                if (p == NULL)
                   1255:                        return SSH_ERR_ALLOC_FAIL;
                   1256:                p->type = type;
                   1257:                p->payload = state->outgoing_packet;
                   1258:                TAILQ_INSERT_TAIL(&state->outgoing, p, next);
                   1259:                state->outgoing_packet = sshbuf_new();
                   1260:                if (state->outgoing_packet == NULL)
                   1261:                        return SSH_ERR_ALLOC_FAIL;
                   1262:                if (need_rekey) {
                   1263:                        /*
                   1264:                         * This packet triggered a rekey, so send the
                   1265:                         * KEXINIT now.
                   1266:                         * NB. reenters this function via kex_start_rekex().
                   1267:                         */
                   1268:                        return kex_start_rekex(ssh);
1.105     markus   1269:                }
1.228     djm      1270:                return 0;
1.105     markus   1271:        }
                   1272:
                   1273:        /* rekeying starts with sending KEXINIT */
                   1274:        if (type == SSH2_MSG_KEXINIT)
1.201     markus   1275:                state->rekeying = 1;
1.105     markus   1276:
1.201     markus   1277:        if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
                   1278:                return r;
1.105     markus   1279:
                   1280:        /* after a NEWKEYS message we can send the complete queue */
                   1281:        if (type == SSH2_MSG_NEWKEYS) {
1.201     markus   1282:                state->rekeying = 0;
                   1283:                state->rekey_time = monotime();
                   1284:                while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105     markus   1285:                        type = p->type;
1.228     djm      1286:                        /*
                   1287:                         * If this packet triggers a rekex, then skip the
                   1288:                         * remaining packets in the queue for now.
                   1289:                         * NB. re-enters this function via kex_start_rekex.
                   1290:                         */
                   1291:                        if (ssh_packet_need_rekeying(ssh,
                   1292:                            sshbuf_len(p->payload))) {
1.297     djm      1293:                                debug3_f("queued packet triggered rekex");
1.228     djm      1294:                                return kex_start_rekex(ssh);
                   1295:                        }
1.105     markus   1296:                        debug("dequeue packet: %u", type);
1.201     markus   1297:                        sshbuf_free(state->outgoing_packet);
                   1298:                        state->outgoing_packet = p->payload;
                   1299:                        TAILQ_REMOVE(&state->outgoing, p, next);
1.228     djm      1300:                        memset(p, 0, sizeof(*p));
1.186     djm      1301:                        free(p);
1.201     markus   1302:                        if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
                   1303:                                return r;
1.105     markus   1304:                }
                   1305:        }
1.201     markus   1306:        return 0;
1.25      markus   1307: }
                   1308:
                   1309: /*
1.16      markus   1310:  * Waits until a packet has been received, and returns its type.  Note that
                   1311:  * no other data is processed until this returns, so this function should not
                   1312:  * be used during the interactive session.
                   1313:  */
1.1       deraadt  1314:
1.2       provos   1315: int
1.201     markus   1316: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1       deraadt  1317: {
1.201     markus   1318:        struct session_state *state = ssh->state;
1.309     dtucker  1319:        int len, r, ms_remain = 0;
1.302     deraadt  1320:        struct pollfd pfd;
1.14      markus   1321:        char buf[8192];
1.302     deraadt  1322:        struct timeval start;
                   1323:        struct timespec timespec, *timespecp = NULL;
1.155     deraadt  1324:
1.25      markus   1325:        DBG(debug("packet_read()"));
1.14      markus   1326:
1.205     djm      1327:        /*
                   1328:         * Since we are blocking, ensure that all written packets have
                   1329:         * been sent.
                   1330:         */
1.210     markus   1331:        if ((r = ssh_packet_write_wait(ssh)) != 0)
                   1332:                goto out;
1.14      markus   1333:
                   1334:        /* Stay in the loop until we have received a complete packet. */
                   1335:        for (;;) {
                   1336:                /* Try to read a packet from the buffer. */
1.313   ! djm      1337:                if ((r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p)) != 0)
1.201     markus   1338:                        break;
1.14      markus   1339:                /* If we got a packet, return it. */
1.201     markus   1340:                if (*typep != SSH_MSG_NONE)
                   1341:                        break;
1.16      markus   1342:                /*
                   1343:                 * Otherwise, wait for some data to arrive, add it to the
                   1344:                 * buffer, and try again.
                   1345:                 */
1.302     deraadt  1346:                pfd.fd = state->connection_in;
                   1347:                pfd.events = POLLIN;
1.16      markus   1348:
1.201     markus   1349:                if (state->packet_timeout_ms > 0) {
                   1350:                        ms_remain = state->packet_timeout_ms;
1.302     deraadt  1351:                        timespecp = &timespec;
1.154     dtucker  1352:                }
1.14      markus   1353:                /* Wait for some data to arrive. */
1.154     dtucker  1354:                for (;;) {
1.291     markus   1355:                        if (state->packet_timeout_ms > 0) {
1.302     deraadt  1356:                                ms_to_timespec(&timespec, ms_remain);
1.267     dtucker  1357:                                monotime_tv(&start);
1.154     dtucker  1358:                        }
1.302     deraadt  1359:                        if ((r = ppoll(&pfd, 1, timespecp, NULL)) >= 0)
1.154     dtucker  1360:                                break;
1.270     dtucker  1361:                        if (errno != EAGAIN && errno != EINTR) {
                   1362:                                r = SSH_ERR_SYSTEM_ERROR;
                   1363:                                goto out;
                   1364:                        }
1.291     markus   1365:                        if (state->packet_timeout_ms <= 0)
1.154     dtucker  1366:                                continue;
                   1367:                        ms_subtract_diff(&start, &ms_remain);
                   1368:                        if (ms_remain <= 0) {
1.201     markus   1369:                                r = 0;
1.154     dtucker  1370:                                break;
                   1371:                        }
                   1372:                }
1.246     djm      1373:                if (r == 0) {
                   1374:                        r = SSH_ERR_CONN_TIMEOUT;
                   1375:                        goto out;
                   1376:                }
1.14      markus   1377:                /* Read data from the socket. */
1.222     markus   1378:                len = read(state->connection_in, buf, sizeof(buf));
1.210     markus   1379:                if (len == 0) {
                   1380:                        r = SSH_ERR_CONN_CLOSED;
                   1381:                        goto out;
                   1382:                }
1.286     deraadt  1383:                if (len == -1) {
1.210     markus   1384:                        r = SSH_ERR_SYSTEM_ERROR;
                   1385:                        goto out;
                   1386:                }
1.204     djm      1387:
1.14      markus   1388:                /* Append it to the buffer. */
1.204     djm      1389:                if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210     markus   1390:                        goto out;
1.14      markus   1391:        }
1.210     markus   1392:  out:
1.201     markus   1393:        return r;
1.1       deraadt  1394: }
                   1395:
1.77      djm      1396: int
1.201     markus   1397: ssh_packet_read(struct ssh *ssh)
1.77      djm      1398: {
1.201     markus   1399:        u_char type;
                   1400:        int r;
                   1401:
                   1402:        if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1.297     djm      1403:                fatal_fr(r, "read");
1.201     markus   1404:        return type;
1.77      djm      1405: }
                   1406:
1.242     markus   1407: static int
                   1408: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
                   1409: {
                   1410:        struct session_state *state = ssh->state;
                   1411:        const u_char *cp;
                   1412:        size_t need;
                   1413:        int r;
                   1414:
                   1415:        if (ssh->kex)
                   1416:                return SSH_ERR_INTERNAL_ERROR;
                   1417:        *typep = SSH_MSG_NONE;
                   1418:        cp = sshbuf_ptr(state->input);
                   1419:        if (state->packlen == 0) {
                   1420:                if (sshbuf_len(state->input) < 4 + 1)
                   1421:                        return 0; /* packet is incomplete */
                   1422:                state->packlen = PEEK_U32(cp);
                   1423:                if (state->packlen < 4 + 1 ||
                   1424:                    state->packlen > PACKET_MAX_SIZE)
                   1425:                        return SSH_ERR_MESSAGE_INCOMPLETE;
                   1426:        }
                   1427:        need = state->packlen + 4;
                   1428:        if (sshbuf_len(state->input) < need)
                   1429:                return 0; /* packet is incomplete */
                   1430:        sshbuf_reset(state->incoming_packet);
                   1431:        if ((r = sshbuf_put(state->incoming_packet, cp + 4,
                   1432:            state->packlen)) != 0 ||
                   1433:            (r = sshbuf_consume(state->input, need)) != 0 ||
                   1434:            (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
                   1435:            (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
                   1436:                return r;
                   1437:        if (ssh_packet_log_type(*typep))
1.297     djm      1438:                debug3_f("type %u", *typep);
1.242     markus   1439:        /* sshbuf_dump(state->incoming_packet, stderr); */
                   1440:        /* reset for next packet */
                   1441:        state->packlen = 0;
                   1442:        return r;
                   1443: }
                   1444:
1.201     markus   1445: int
                   1446: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25      markus   1447: {
1.201     markus   1448:        struct session_state *state = ssh->state;
1.40      markus   1449:        u_int padlen, need;
1.231     djm      1450:        u_char *cp;
1.201     markus   1451:        u_int maclen, aadlen = 0, authlen = 0, block_size;
                   1452:        struct sshenc *enc   = NULL;
                   1453:        struct sshmac *mac   = NULL;
                   1454:        struct sshcomp *comp = NULL;
1.200     markus   1455:        int r;
1.201     markus   1456:
1.242     markus   1457:        if (state->mux)
                   1458:                return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
                   1459:
1.201     markus   1460:        *typep = SSH_MSG_NONE;
                   1461:
                   1462:        if (state->packet_discard)
                   1463:                return 0;
                   1464:
                   1465:        if (state->newkeys[MODE_IN] != NULL) {
                   1466:                enc  = &state->newkeys[MODE_IN]->enc;
                   1467:                mac  = &state->newkeys[MODE_IN]->mac;
                   1468:                comp = &state->newkeys[MODE_IN]->comp;
1.180     markus   1469:                /* disable mac for authenticated encryption */
                   1470:                if ((authlen = cipher_authlen(enc->cipher)) != 0)
                   1471:                        mac = NULL;
1.25      markus   1472:        }
                   1473:        maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88      markus   1474:        block_size = enc ? enc->block_size : 8;
1.180     markus   1475:        aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25      markus   1476:
1.201     markus   1477:        if (aadlen && state->packlen == 0) {
1.235     djm      1478:                if (cipher_get_length(state->receive_context,
1.201     markus   1479:                    &state->packlen, state->p_read.seqnr,
                   1480:                    sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
                   1481:                        return 0;
                   1482:                if (state->packlen < 1 + 4 ||
                   1483:                    state->packlen > PACKET_MAX_SIZE) {
1.178     markus   1484: #ifdef PACKET_DEBUG
1.201     markus   1485:                        sshbuf_dump(state->input, stderr);
1.178     markus   1486: #endif
1.201     markus   1487:                        logit("Bad packet length %u.", state->packlen);
                   1488:                        if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
                   1489:                                return r;
1.217     djm      1490:                        return SSH_ERR_CONN_CORRUPT;
1.178     markus   1491:                }
1.201     markus   1492:                sshbuf_reset(state->incoming_packet);
                   1493:        } else if (state->packlen == 0) {
1.25      markus   1494:                /*
                   1495:                 * check if input size is less than the cipher block size,
                   1496:                 * decrypt first block and extract length of incoming packet
                   1497:                 */
1.201     markus   1498:                if (sshbuf_len(state->input) < block_size)
                   1499:                        return 0;
                   1500:                sshbuf_reset(state->incoming_packet);
                   1501:                if ((r = sshbuf_reserve(state->incoming_packet, block_size,
                   1502:                    &cp)) != 0)
                   1503:                        goto out;
1.235     djm      1504:                if ((r = cipher_crypt(state->receive_context,
1.201     markus   1505:                    state->p_send.seqnr, cp, sshbuf_ptr(state->input),
                   1506:                    block_size, 0, 0)) != 0)
                   1507:                        goto out;
                   1508:                state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
                   1509:                if (state->packlen < 1 + 4 ||
                   1510:                    state->packlen > PACKET_MAX_SIZE) {
1.110     markus   1511: #ifdef PACKET_DEBUG
1.201     markus   1512:                        fprintf(stderr, "input: \n");
                   1513:                        sshbuf_dump(state->input, stderr);
                   1514:                        fprintf(stderr, "incoming_packet: \n");
                   1515:                        sshbuf_dump(state->incoming_packet, stderr);
1.110     markus   1516: #endif
1.201     markus   1517:                        logit("Bad packet length %u.", state->packlen);
1.234     markus   1518:                        return ssh_packet_start_discard(ssh, enc, mac, 0,
                   1519:                            PACKET_MAX_SIZE);
1.25      markus   1520:                }
1.201     markus   1521:                if ((r = sshbuf_consume(state->input, block_size)) != 0)
                   1522:                        goto out;
1.25      markus   1523:        }
1.201     markus   1524:        DBG(debug("input: packet len %u", state->packlen+4));
                   1525:
1.178     markus   1526:        if (aadlen) {
                   1527:                /* only the payload is encrypted */
1.201     markus   1528:                need = state->packlen;
1.178     markus   1529:        } else {
                   1530:                /*
                   1531:                 * the payload size and the payload are encrypted, but we
                   1532:                 * have a partial packet of block_size bytes
                   1533:                 */
1.201     markus   1534:                need = 4 + state->packlen - block_size;
1.178     markus   1535:        }
1.180     markus   1536:        DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
                   1537:            " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158     markus   1538:        if (need % block_size != 0) {
                   1539:                logit("padding error: need %d block %d mod %d",
1.25      markus   1540:                    need, block_size, need % block_size);
1.234     markus   1541:                return ssh_packet_start_discard(ssh, enc, mac, 0,
                   1542:                    PACKET_MAX_SIZE - block_size);
1.158     markus   1543:        }
1.25      markus   1544:        /*
                   1545:         * check if the entire packet has been received and
1.178     markus   1546:         * decrypt into incoming_packet:
                   1547:         * 'aadlen' bytes are unencrypted, but authenticated.
1.180     markus   1548:         * 'need' bytes are encrypted, followed by either
                   1549:         * 'authlen' bytes of authentication tag or
1.178     markus   1550:         * 'maclen' bytes of message authentication code.
1.25      markus   1551:         */
1.201     markus   1552:        if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231     djm      1553:                return 0; /* packet is incomplete */
1.25      markus   1554: #ifdef PACKET_DEBUG
                   1555:        fprintf(stderr, "read_poll enc/full: ");
1.201     markus   1556:        sshbuf_dump(state->input, stderr);
1.25      markus   1557: #endif
1.231     djm      1558:        /* EtM: check mac over encrypted input */
1.201     markus   1559:        if (mac && mac->enabled && mac->etm) {
1.231     djm      1560:                if ((r = mac_check(mac, state->p_read.seqnr,
1.201     markus   1561:                    sshbuf_ptr(state->input), aadlen + need,
1.231     djm      1562:                    sshbuf_ptr(state->input) + aadlen + need + authlen,
                   1563:                    maclen)) != 0) {
                   1564:                        if (r == SSH_ERR_MAC_INVALID)
                   1565:                                logit("Corrupted MAC on input.");
1.201     markus   1566:                        goto out;
1.231     djm      1567:                }
1.201     markus   1568:        }
                   1569:        if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
                   1570:            &cp)) != 0)
                   1571:                goto out;
1.235     djm      1572:        if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201     markus   1573:            sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
                   1574:                goto out;
                   1575:        if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
                   1576:                goto out;
1.29      markus   1577:        if (mac && mac->enabled) {
1.231     djm      1578:                /* Not EtM: check MAC over cleartext */
                   1579:                if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
                   1580:                    sshbuf_ptr(state->incoming_packet),
                   1581:                    sshbuf_len(state->incoming_packet),
                   1582:                    sshbuf_ptr(state->input), maclen)) != 0) {
                   1583:                        if (r != SSH_ERR_MAC_INVALID)
1.201     markus   1584:                                goto out;
1.159     markus   1585:                        logit("Corrupted MAC on input.");
1.247     markus   1586:                        if (need + block_size > PACKET_MAX_SIZE)
1.201     markus   1587:                                return SSH_ERR_INTERNAL_ERROR;
                   1588:                        return ssh_packet_start_discard(ssh, enc, mac,
1.234     markus   1589:                            sshbuf_len(state->incoming_packet),
1.247     markus   1590:                            PACKET_MAX_SIZE - need - block_size);
1.201     markus   1591:                }
1.231     djm      1592:                /* Remove MAC from input buffer */
1.201     markus   1593:                DBG(debug("MAC #%d ok", state->p_read.seqnr));
                   1594:                if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
                   1595:                        goto out;
1.25      markus   1596:        }
1.313   ! djm      1597:
1.77      djm      1598:        if (seqnr_p != NULL)
1.201     markus   1599:                *seqnr_p = state->p_read.seqnr;
1.313   ! djm      1600:        if (++state->p_read.seqnr == 0) {
        !          1601:                if ((ssh->kex->flags & KEX_INITIAL) != 0) {
        !          1602:                        ssh_packet_disconnect(ssh, "incoming sequence number "
        !          1603:                            "wrapped during initial key exchange");
        !          1604:                }
1.106     itojun   1605:                logit("incoming seqnr wraps around");
1.313   ! djm      1606:        }
1.201     markus   1607:        if (++state->p_read.packets == 0)
                   1608:                if (!(ssh->compat & SSH_BUG_NOREKEY))
                   1609:                        return SSH_ERR_NEED_REKEY;
                   1610:        state->p_read.blocks += (state->packlen + 4) / block_size;
                   1611:        state->p_read.bytes += state->packlen + 4;
1.25      markus   1612:
                   1613:        /* get padlen */
1.201     markus   1614:        padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25      markus   1615:        DBG(debug("input: padlen %d", padlen));
1.205     djm      1616:        if (padlen < 4) {
                   1617:                if ((r = sshpkt_disconnect(ssh,
                   1618:                    "Corrupted padlen %d on input.", padlen)) != 0 ||
                   1619:                    (r = ssh_packet_write_wait(ssh)) != 0)
                   1620:                        return r;
                   1621:                return SSH_ERR_CONN_CORRUPT;
                   1622:        }
1.25      markus   1623:
                   1624:        /* skip packet size + padlen, discard padding */
1.201     markus   1625:        if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
                   1626:            ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
                   1627:                goto out;
1.25      markus   1628:
1.201     markus   1629:        DBG(debug("input: len before de-compress %zd",
                   1630:            sshbuf_len(state->incoming_packet)));
1.25      markus   1631:        if (comp && comp->enabled) {
1.201     markus   1632:                sshbuf_reset(state->compression_buffer);
                   1633:                if ((r = uncompress_buffer(ssh, state->incoming_packet,
                   1634:                    state->compression_buffer)) != 0)
                   1635:                        goto out;
                   1636:                sshbuf_reset(state->incoming_packet);
                   1637:                if ((r = sshbuf_putb(state->incoming_packet,
                   1638:                    state->compression_buffer)) != 0)
                   1639:                        goto out;
                   1640:                DBG(debug("input: len after de-compress %zd",
                   1641:                    sshbuf_len(state->incoming_packet)));
1.25      markus   1642:        }
                   1643:        /*
                   1644:         * get packet type, implies consume.
                   1645:         * return length of payload (without type field)
                   1646:         */
1.201     markus   1647:        if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
                   1648:                goto out;
1.226     djm      1649:        if (ssh_packet_log_type(*typep))
                   1650:                debug3("receive packet: type %u", *typep);
1.311     djm      1651:        if (*typep < SSH2_MSG_MIN) {
1.205     djm      1652:                if ((r = sshpkt_disconnect(ssh,
                   1653:                    "Invalid ssh2 packet type: %d", *typep)) != 0 ||
                   1654:                    (r = ssh_packet_write_wait(ssh)) != 0)
                   1655:                        return r;
                   1656:                return SSH_ERR_PROTOCOL_ERROR;
                   1657:        }
1.243     djm      1658:        if (state->hook_in != NULL &&
                   1659:            (r = state->hook_in(ssh, state->incoming_packet, typep,
                   1660:            state->hook_in_ctx)) != 0)
                   1661:                return r;
1.238     markus   1662:        if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201     markus   1663:                r = ssh_packet_enable_delayed_compress(ssh);
                   1664:        else
                   1665:                r = 0;
1.25      markus   1666: #ifdef PACKET_DEBUG
1.201     markus   1667:        fprintf(stderr, "read/plain[%d]:\r\n", *typep);
                   1668:        sshbuf_dump(state->incoming_packet, stderr);
1.25      markus   1669: #endif
1.62      markus   1670:        /* reset for next packet */
1.201     markus   1671:        state->packlen = 0;
1.313   ! djm      1672:        if (*typep == SSH2_MSG_NEWKEYS && ssh->kex->kex_strict) {
        !          1673:                debug_f("resetting read seqnr %u", state->p_read.seqnr);
        !          1674:                state->p_read.seqnr = 0;
        !          1675:        }
1.228     djm      1676:
1.301     djm      1677:        if ((r = ssh_packet_check_rekey(ssh)) != 0)
                   1678:                return r;
1.201     markus   1679:  out:
                   1680:        return r;
1.25      markus   1681: }
                   1682:
                   1683: int
1.201     markus   1684: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25      markus   1685: {
1.201     markus   1686:        struct session_state *state = ssh->state;
1.96      deraadt  1687:        u_int reason, seqnr;
1.201     markus   1688:        int r;
                   1689:        u_char *msg;
1.311     djm      1690:        const u_char *d;
                   1691:        size_t len;
1.62      markus   1692:
1.25      markus   1693:        for (;;) {
1.201     markus   1694:                msg = NULL;
1.249     djm      1695:                r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
                   1696:                if (r != 0)
                   1697:                        return r;
1.313   ! djm      1698:                if (*typep == 0) {
        !          1699:                        /* no message ready */
        !          1700:                        return 0;
1.249     djm      1701:                }
1.313   ! djm      1702:                state->keep_alive_timeouts = 0;
        !          1703:                DBG(debug("received packet type %d", *typep));
        !          1704:
        !          1705:                /* Always process disconnect messages */
        !          1706:                if (*typep == SSH2_MSG_DISCONNECT) {
        !          1707:                        if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
        !          1708:                            (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
        !          1709:                                return r;
        !          1710:                        /* Ignore normal client exit notifications */
        !          1711:                        do_log2(ssh->state->server_side &&
        !          1712:                            reason == SSH2_DISCONNECT_BY_APPLICATION ?
        !          1713:                            SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
        !          1714:                            "Received disconnect from %s port %d:"
        !          1715:                            "%u: %.400s", ssh_remote_ipaddr(ssh),
        !          1716:                            ssh_remote_port(ssh), reason, msg);
        !          1717:                        free(msg);
        !          1718:                        return SSH_ERR_DISCONNECTED;
        !          1719:                }
        !          1720:
        !          1721:                /*
        !          1722:                 * Do not implicitly handle any messages here during initial
        !          1723:                 * KEX when in strict mode. They will be need to be allowed
        !          1724:                 * explicitly by the KEX dispatch table or they will generate
        !          1725:                 * protocol errors.
        !          1726:                 */
        !          1727:                if (ssh->kex != NULL &&
        !          1728:                    (ssh->kex->flags & KEX_INITIAL) && ssh->kex->kex_strict)
        !          1729:                        return 0;
        !          1730:                /* Implicitly handle transport-level messages */
1.249     djm      1731:                switch (*typep) {
                   1732:                case SSH2_MSG_IGNORE:
                   1733:                        debug3("Received SSH2_MSG_IGNORE");
                   1734:                        break;
                   1735:                case SSH2_MSG_DEBUG:
                   1736:                        if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
                   1737:                            (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
                   1738:                            (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
                   1739:                                free(msg);
1.201     markus   1740:                                return r;
1.48      stevesk  1741:                        }
1.249     djm      1742:                        debug("Remote: %.900s", msg);
                   1743:                        free(msg);
                   1744:                        break;
                   1745:                case SSH2_MSG_UNIMPLEMENTED:
                   1746:                        if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
                   1747:                                return r;
                   1748:                        debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
                   1749:                            seqnr);
1.311     djm      1750:                        break;
                   1751:                case SSH2_MSG_PING:
                   1752:                        if ((r = sshpkt_get_string_direct(ssh, &d, &len)) != 0)
                   1753:                                return r;
                   1754:                        DBG(debug("Received SSH2_MSG_PING len %zu", len));
                   1755:                        if ((r = sshpkt_start(ssh, SSH2_MSG_PONG)) != 0 ||
                   1756:                            (r = sshpkt_put_string(ssh, d, len)) != 0 ||
                   1757:                            (r = sshpkt_send(ssh)) != 0)
                   1758:                                return r;
                   1759:                        break;
                   1760:                case SSH2_MSG_PONG:
                   1761:                        if ((r = sshpkt_get_string_direct(ssh,
                   1762:                            NULL, &len)) != 0)
                   1763:                                return r;
                   1764:                        DBG(debug("Received SSH2_MSG_PONG len %zu", len));
1.249     djm      1765:                        break;
                   1766:                default:
                   1767:                        return 0;
1.25      markus   1768:                }
                   1769:        }
                   1770: }
                   1771:
1.16      markus   1772: /*
1.306     djm      1773:  * Buffers the supplied input data. This is intended to be used together
                   1774:  * with packet_read_poll().
1.16      markus   1775:  */
1.204     djm      1776: int
1.201     markus   1777: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1       deraadt  1778: {
1.201     markus   1779:        struct session_state *state = ssh->state;
                   1780:        int r;
                   1781:
                   1782:        if (state->packet_discard) {
                   1783:                state->keep_alive_timeouts = 0; /* ?? */
                   1784:                if (len >= state->packet_discard) {
                   1785:                        if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204     djm      1786:                                return r;
1.201     markus   1787:                }
                   1788:                state->packet_discard -= len;
1.204     djm      1789:                return 0;
1.159     markus   1790:        }
1.306     djm      1791:        if ((r = sshbuf_put(state->input, buf, len)) != 0)
1.204     djm      1792:                return r;
                   1793:
1.307     djm      1794:        return 0;
                   1795: }
                   1796:
                   1797: /* Reads and buffers data from the specified fd */
                   1798: int
                   1799: ssh_packet_process_read(struct ssh *ssh, int fd)
                   1800: {
                   1801:        struct session_state *state = ssh->state;
                   1802:        int r;
                   1803:        size_t rlen;
                   1804:
                   1805:        if ((r = sshbuf_read(fd, state->input, PACKET_MAX_SIZE, &rlen)) != 0)
                   1806:                return r;
                   1807:
                   1808:        if (state->packet_discard) {
                   1809:                if ((r = sshbuf_consume_end(state->input, rlen)) != 0)
                   1810:                        return r;
                   1811:                state->keep_alive_timeouts = 0; /* ?? */
                   1812:                if (rlen >= state->packet_discard) {
                   1813:                        if ((r = ssh_packet_stop_discard(ssh)) != 0)
                   1814:                                return r;
                   1815:                }
                   1816:                state->packet_discard -= rlen;
                   1817:                return 0;
                   1818:        }
1.204     djm      1819:        return 0;
1.28      markus   1820: }
                   1821:
                   1822: int
1.201     markus   1823: ssh_packet_remaining(struct ssh *ssh)
1.28      markus   1824: {
1.201     markus   1825:        return sshbuf_len(ssh->state->incoming_packet);
1.1       deraadt  1826: }
                   1827:
1.16      markus   1828: /*
                   1829:  * Sends a diagnostic message from the server to the client.  This message
                   1830:  * can be sent at any time (but not while constructing another message). The
                   1831:  * message is printed immediately, but only if the client is being executed
                   1832:  * in verbose mode.  These messages are primarily intended to ease debugging
                   1833:  * authentication problems.   The length of the formatted message must not
1.205     djm      1834:  * exceed 1024 bytes.  This will automatically call ssh_packet_write_wait.
1.16      markus   1835:  */
1.2       provos   1836: void
1.201     markus   1837: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1       deraadt  1838: {
1.14      markus   1839:        char buf[1024];
                   1840:        va_list args;
1.201     markus   1841:        int r;
1.39      markus   1842:
1.249     djm      1843:        if ((ssh->compat & SSH_BUG_DEBUG))
1.39      markus   1844:                return;
1.14      markus   1845:
                   1846:        va_start(args, fmt);
                   1847:        vsnprintf(buf, sizeof(buf), fmt, args);
                   1848:        va_end(args);
1.265     djm      1849:
                   1850:        debug3("sending debug message: %s", buf);
1.14      markus   1851:
1.249     djm      1852:        if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
                   1853:            (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
                   1854:            (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
                   1855:            (r = sshpkt_put_cstring(ssh, "")) != 0 ||
                   1856:            (r = sshpkt_send(ssh)) != 0 ||
                   1857:            (r = ssh_packet_write_wait(ssh)) != 0)
1.297     djm      1858:                fatal_fr(r, "send DEBUG");
1.205     djm      1859: }
                   1860:
1.268     dtucker  1861: void
                   1862: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245     djm      1863: {
                   1864:        snprintf(s, l, "%.200s%s%s port %d",
                   1865:            ssh->log_preamble ? ssh->log_preamble : "",
                   1866:            ssh->log_preamble ? " " : "",
                   1867:            ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
                   1868: }
                   1869:
1.205     djm      1870: /*
                   1871:  * Pretty-print connection-terminating errors and exit.
                   1872:  */
1.280     djm      1873: static void
                   1874: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205     djm      1875: {
1.280     djm      1876:        char *tag = NULL, remote_id[512];
1.290     djm      1877:        int oerrno = errno;
1.245     djm      1878:
1.268     dtucker  1879:        sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245     djm      1880:
1.205     djm      1881:        switch (r) {
                   1882:        case SSH_ERR_CONN_CLOSED:
1.257     markus   1883:                ssh_packet_clear_keys(ssh);
1.245     djm      1884:                logdie("Connection closed by %s", remote_id);
1.205     djm      1885:        case SSH_ERR_CONN_TIMEOUT:
1.257     markus   1886:                ssh_packet_clear_keys(ssh);
1.245     djm      1887:                logdie("Connection %s %s timed out",
                   1888:                    ssh->state->server_side ? "from" : "to", remote_id);
1.212     djm      1889:        case SSH_ERR_DISCONNECTED:
1.257     markus   1890:                ssh_packet_clear_keys(ssh);
1.245     djm      1891:                logdie("Disconnected from %s", remote_id);
1.212     djm      1892:        case SSH_ERR_SYSTEM_ERROR:
1.257     markus   1893:                if (errno == ECONNRESET) {
                   1894:                        ssh_packet_clear_keys(ssh);
1.245     djm      1895:                        logdie("Connection reset by %s", remote_id);
1.257     markus   1896:                }
1.213     djm      1897:                /* FALLTHROUGH */
                   1898:        case SSH_ERR_NO_CIPHER_ALG_MATCH:
                   1899:        case SSH_ERR_NO_MAC_ALG_MATCH:
                   1900:        case SSH_ERR_NO_COMPRESS_ALG_MATCH:
                   1901:        case SSH_ERR_NO_KEX_ALG_MATCH:
                   1902:        case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1.310     djm      1903:                if (ssh->kex && ssh->kex->failed_choice) {
1.257     markus   1904:                        ssh_packet_clear_keys(ssh);
1.290     djm      1905:                        errno = oerrno;
1.245     djm      1906:                        logdie("Unable to negotiate with %s: %s. "
                   1907:                            "Their offer: %s", remote_id, ssh_err(r),
1.220     djm      1908:                            ssh->kex->failed_choice);
1.212     djm      1909:                }
                   1910:                /* FALLTHROUGH */
1.205     djm      1911:        default:
1.280     djm      1912:                if (vasprintf(&tag, fmt, ap) == -1) {
                   1913:                        ssh_packet_clear_keys(ssh);
1.297     djm      1914:                        logdie_f("could not allocate failure message");
1.280     djm      1915:                }
1.257     markus   1916:                ssh_packet_clear_keys(ssh);
1.290     djm      1917:                errno = oerrno;
1.297     djm      1918:                logdie_r(r, "%s%sConnection %s %s",
1.205     djm      1919:                    tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.297     djm      1920:                    ssh->state->server_side ? "from" : "to", remote_id);
1.205     djm      1921:        }
1.1       deraadt  1922: }
                   1923:
1.280     djm      1924: void
                   1925: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
                   1926: {
                   1927:        va_list ap;
                   1928:
                   1929:        va_start(ap, fmt);
                   1930:        sshpkt_vfatal(ssh, r, fmt, ap);
                   1931:        /* NOTREACHED */
                   1932:        va_end(ap);
1.297     djm      1933:        logdie_f("should have exited");
1.280     djm      1934: }
                   1935:
1.16      markus   1936: /*
                   1937:  * Logs the error plus constructs and sends a disconnect packet, closes the
                   1938:  * connection, and exits.  This function never returns. The error message
                   1939:  * should not contain a newline.  The length of the formatted message must
                   1940:  * not exceed 1024 bytes.
                   1941:  */
1.2       provos   1942: void
1.201     markus   1943: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1       deraadt  1944: {
1.245     djm      1945:        char buf[1024], remote_id[512];
1.14      markus   1946:        va_list args;
                   1947:        static int disconnecting = 0;
1.201     markus   1948:        int r;
1.97      deraadt  1949:
1.14      markus   1950:        if (disconnecting)      /* Guard against recursive invocations. */
                   1951:                fatal("packet_disconnect called recursively.");
                   1952:        disconnecting = 1;
                   1953:
1.16      markus   1954:        /*
                   1955:         * Format the message.  Note that the caller must make sure the
                   1956:         * message is of limited size.
                   1957:         */
1.268     dtucker  1958:        sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14      markus   1959:        va_start(args, fmt);
                   1960:        vsnprintf(buf, sizeof(buf), fmt, args);
                   1961:        va_end(args);
                   1962:
1.99      markus   1963:        /* Display the error locally */
1.245     djm      1964:        logit("Disconnecting %s: %.100s", remote_id, buf);
1.99      markus   1965:
1.205     djm      1966:        /*
                   1967:         * Send the disconnect message to the other side, and wait
                   1968:         * for it to get sent.
                   1969:         */
                   1970:        if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280     djm      1971:                sshpkt_fatal(ssh, r, "%s", __func__);
1.205     djm      1972:
                   1973:        if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280     djm      1974:                sshpkt_fatal(ssh, r, "%s", __func__);
1.14      markus   1975:
                   1976:        /* Close the connection. */
1.201     markus   1977:        ssh_packet_close(ssh);
1.112     markus   1978:        cleanup_exit(255);
1.1       deraadt  1979: }
                   1980:
1.205     djm      1981: /*
                   1982:  * Checks if there is any buffered output, and tries to write some of
                   1983:  * the output.
                   1984:  */
                   1985: int
1.201     markus   1986: ssh_packet_write_poll(struct ssh *ssh)
1.1       deraadt  1987: {
1.201     markus   1988:        struct session_state *state = ssh->state;
                   1989:        int len = sshbuf_len(state->output);
1.222     markus   1990:        int r;
1.97      deraadt  1991:
1.14      markus   1992:        if (len > 0) {
1.222     markus   1993:                len = write(state->connection_out,
                   1994:                    sshbuf_ptr(state->output), len);
1.156     djm      1995:                if (len == -1) {
                   1996:                        if (errno == EINTR || errno == EAGAIN)
1.205     djm      1997:                                return 0;
                   1998:                        return SSH_ERR_SYSTEM_ERROR;
1.14      markus   1999:                }
1.222     markus   2000:                if (len == 0)
1.205     djm      2001:                        return SSH_ERR_CONN_CLOSED;
1.201     markus   2002:                if ((r = sshbuf_consume(state->output, len)) != 0)
1.205     djm      2003:                        return r;
1.14      markus   2004:        }
1.205     djm      2005:        return 0;
1.1       deraadt  2006: }
                   2007:
1.16      markus   2008: /*
                   2009:  * Calls packet_write_poll repeatedly until all pending output data has been
                   2010:  * written.
                   2011:  */
1.205     djm      2012: int
1.201     markus   2013: ssh_packet_write_wait(struct ssh *ssh)
1.1       deraadt  2014: {
1.205     djm      2015:        int ret, r, ms_remain = 0;
1.302     deraadt  2016:        struct timeval start;
                   2017:        struct timespec timespec, *timespecp = NULL;
1.201     markus   2018:        struct session_state *state = ssh->state;
1.302     deraadt  2019:        struct pollfd pfd;
1.56      millert  2020:
1.302     deraadt  2021:        if ((r = ssh_packet_write_poll(ssh)) != 0)
1.215     djm      2022:                return r;
1.201     markus   2023:        while (ssh_packet_have_data_to_write(ssh)) {
1.302     deraadt  2024:                pfd.fd = state->connection_out;
                   2025:                pfd.events = POLLOUT;
1.154     dtucker  2026:
1.201     markus   2027:                if (state->packet_timeout_ms > 0) {
                   2028:                        ms_remain = state->packet_timeout_ms;
1.302     deraadt  2029:                        timespecp = &timespec;
1.154     dtucker  2030:                }
                   2031:                for (;;) {
1.291     markus   2032:                        if (state->packet_timeout_ms > 0) {
1.302     deraadt  2033:                                ms_to_timespec(&timespec, ms_remain);
1.267     dtucker  2034:                                monotime_tv(&start);
1.154     dtucker  2035:                        }
1.302     deraadt  2036:                        if ((ret = ppoll(&pfd, 1, timespecp, NULL)) >= 0)
1.154     dtucker  2037:                                break;
1.161     andreas  2038:                        if (errno != EAGAIN && errno != EINTR)
1.154     dtucker  2039:                                break;
1.291     markus   2040:                        if (state->packet_timeout_ms <= 0)
1.154     dtucker  2041:                                continue;
                   2042:                        ms_subtract_diff(&start, &ms_remain);
                   2043:                        if (ms_remain <= 0) {
                   2044:                                ret = 0;
                   2045:                                break;
                   2046:                        }
                   2047:                }
1.302     deraadt  2048:                if (ret == 0)
1.205     djm      2049:                        return SSH_ERR_CONN_TIMEOUT;
1.302     deraadt  2050:                if ((r = ssh_packet_write_poll(ssh)) != 0)
1.205     djm      2051:                        return r;
1.14      markus   2052:        }
1.205     djm      2053:        return 0;
1.1       deraadt  2054: }
                   2055:
                   2056: /* Returns true if there is buffered data to write to the connection. */
                   2057:
1.2       provos   2058: int
1.201     markus   2059: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1       deraadt  2060: {
1.201     markus   2061:        return sshbuf_len(ssh->state->output) != 0;
1.1       deraadt  2062: }
                   2063:
                   2064: /* Returns true if there is not too much data to write to the connection. */
                   2065:
1.2       provos   2066: int
1.201     markus   2067: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1       deraadt  2068: {
1.201     markus   2069:        if (ssh->state->interactive_mode)
                   2070:                return sshbuf_len(ssh->state->output) < 16384;
1.14      markus   2071:        else
1.201     markus   2072:                return sshbuf_len(ssh->state->output) < 128 * 1024;
1.312     djm      2073: }
                   2074:
                   2075: /*
                   2076:  * returns true when there are at most a few keystrokes of data to write
                   2077:  * and the connection is in interactive mode.
                   2078:  */
                   2079:
                   2080: int
                   2081: ssh_packet_interactive_data_to_write(struct ssh *ssh)
                   2082: {
                   2083:        return ssh->state->interactive_mode &&
                   2084:            sshbuf_len(ssh->state->output) < 256;
1.1       deraadt  2085: }
                   2086:
1.201     markus   2087: void
                   2088: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101     markus   2089: {
1.263     djm      2090:        if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101     markus   2091:                return;
1.298     djm      2092:        set_sock_tos(ssh->state->connection_in, tos);
1.101     markus   2093: }
                   2094:
1.1       deraadt  2095: /* Informs that the current session is interactive.  Sets IP flags for that. */
                   2096:
1.2       provos   2097: void
1.201     markus   2098: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1       deraadt  2099: {
1.201     markus   2100:        struct session_state *state = ssh->state;
                   2101:
                   2102:        if (state->set_interactive_called)
1.43      markus   2103:                return;
1.201     markus   2104:        state->set_interactive_called = 1;
1.1       deraadt  2105:
1.14      markus   2106:        /* Record that we are in interactive mode. */
1.201     markus   2107:        state->interactive_mode = interactive;
1.1       deraadt  2108:
1.19      markus   2109:        /* Only set socket options if using a socket.  */
1.201     markus   2110:        if (!ssh_packet_connection_is_on_socket(ssh))
1.14      markus   2111:                return;
1.201     markus   2112:        set_nodelay(state->connection_in);
1.298     djm      2113:        ssh_packet_set_tos(ssh, interactive ? qos_interactive : qos_bulk);
1.1       deraadt  2114: }
                   2115:
                   2116: /* Returns true if the current connection is interactive. */
                   2117:
1.2       provos   2118: int
1.201     markus   2119: ssh_packet_is_interactive(struct ssh *ssh)
1.1       deraadt  2120: {
1.201     markus   2121:        return ssh->state->interactive_mode;
1.12      markus   2122: }
                   2123:
1.113     deraadt  2124: int
1.201     markus   2125: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12      markus   2126: {
1.201     markus   2127:        struct session_state *state = ssh->state;
                   2128:
                   2129:        if (state->set_maxsize_called) {
1.303     djm      2130:                logit_f("called twice: old %d new %d",
1.201     markus   2131:                    state->max_packet_size, s);
1.14      markus   2132:                return -1;
                   2133:        }
                   2134:        if (s < 4 * 1024 || s > 1024 * 1024) {
1.303     djm      2135:                logit_f("bad size %d", s);
1.14      markus   2136:                return -1;
                   2137:        }
1.201     markus   2138:        state->set_maxsize_called = 1;
1.303     djm      2139:        debug_f("setting to %d", s);
1.201     markus   2140:        state->max_packet_size = s;
1.14      markus   2141:        return s;
1.53      markus   2142: }
                   2143:
1.161     andreas  2144: int
1.201     markus   2145: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161     andreas  2146: {
1.201     markus   2147:        return ++ssh->state->keep_alive_timeouts;
1.161     andreas  2148: }
                   2149:
                   2150: void
1.201     markus   2151: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161     andreas  2152: {
1.201     markus   2153:        ssh->state->keep_alive_timeouts = ka;
1.161     andreas  2154: }
                   2155:
                   2156: u_int
1.201     markus   2157: ssh_packet_get_maxsize(struct ssh *ssh)
1.71      markus   2158: {
1.201     markus   2159:        return ssh->state->max_packet_size;
1.71      markus   2160: }
                   2161:
1.105     markus   2162: void
1.244     dtucker  2163: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105     markus   2164: {
1.244     dtucker  2165:        debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
                   2166:            (unsigned int)seconds);
1.201     markus   2167:        ssh->state->rekey_limit = bytes;
                   2168:        ssh->state->rekey_interval = seconds;
1.184     dtucker  2169: }
                   2170:
                   2171: time_t
1.201     markus   2172: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184     dtucker  2173: {
                   2174:        time_t seconds;
                   2175:
1.201     markus   2176:        seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187     dtucker  2177:            monotime();
1.185     dtucker  2178:        return (seconds <= 0 ? 1 : seconds);
1.118     markus   2179: }
                   2180:
                   2181: void
1.201     markus   2182: ssh_packet_set_server(struct ssh *ssh)
1.118     markus   2183: {
1.201     markus   2184:        ssh->state->server_side = 1;
1.278     djm      2185:        ssh->kex->server = 1; /* XXX unify? */
1.118     markus   2186: }
                   2187:
                   2188: void
1.201     markus   2189: ssh_packet_set_authenticated(struct ssh *ssh)
1.118     markus   2190: {
1.201     markus   2191:        ssh->state->after_authentication = 1;
1.161     andreas  2192: }
                   2193:
                   2194: void *
1.201     markus   2195: ssh_packet_get_input(struct ssh *ssh)
1.161     andreas  2196: {
1.201     markus   2197:        return (void *)ssh->state->input;
1.161     andreas  2198: }
                   2199:
                   2200: void *
1.201     markus   2201: ssh_packet_get_output(struct ssh *ssh)
1.161     andreas  2202: {
1.201     markus   2203:        return (void *)ssh->state->output;
1.166     andreas  2204: }
                   2205:
1.196     markus   2206: /* Reset after_authentication and reset compression in post-auth privsep */
1.201     markus   2207: static int
                   2208: ssh_packet_set_postauth(struct ssh *ssh)
1.196     markus   2209: {
1.239     djm      2210:        int r;
1.196     markus   2211:
1.297     djm      2212:        debug_f("called");
1.196     markus   2213:        /* This was set in net child, but is not visible in user child */
1.201     markus   2214:        ssh->state->after_authentication = 1;
                   2215:        ssh->state->rekeying = 0;
1.239     djm      2216:        if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
                   2217:                return r;
1.201     markus   2218:        return 0;
                   2219: }
                   2220:
                   2221: /* Packet state (de-)serialization for privsep */
                   2222:
                   2223: /* turn kex into a blob for packet state serialization */
                   2224: static int
                   2225: kex_to_blob(struct sshbuf *m, struct kex *kex)
                   2226: {
                   2227:        int r;
                   2228:
1.299     djm      2229:        if ((r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269     djm      2230:            (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201     markus   2231:            (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269     djm      2232:            (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201     markus   2233:            (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
1.313   ! djm      2234:            (r = sshbuf_put_u32(m, kex->kex_strict)) != 0 ||
1.201     markus   2235:            (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
                   2236:            (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278     djm      2237:            (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
                   2238:            (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
1.299     djm      2239:            (r = sshbuf_put_stringb(m, kex->session_id)) != 0 ||
1.278     djm      2240:            (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201     markus   2241:                return r;
                   2242:        return 0;
                   2243: }
                   2244:
                   2245: /* turn key exchange results into a blob for packet state serialization */
                   2246: static int
                   2247: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
                   2248: {
                   2249:        struct sshbuf *b;
                   2250:        struct sshcipher_ctx *cc;
                   2251:        struct sshcomp *comp;
                   2252:        struct sshenc *enc;
                   2253:        struct sshmac *mac;
                   2254:        struct newkeys *newkey;
                   2255:        int r;
                   2256:
                   2257:        if ((newkey = ssh->state->newkeys[mode]) == NULL)
                   2258:                return SSH_ERR_INTERNAL_ERROR;
                   2259:        enc = &newkey->enc;
                   2260:        mac = &newkey->mac;
                   2261:        comp = &newkey->comp;
1.235     djm      2262:        cc = (mode == MODE_OUT) ? ssh->state->send_context :
                   2263:            ssh->state->receive_context;
1.201     markus   2264:        if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
                   2265:                return r;
                   2266:        if ((b = sshbuf_new()) == NULL)
                   2267:                return SSH_ERR_ALLOC_FAIL;
                   2268:        if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
                   2269:            (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
                   2270:            (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
                   2271:            (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
                   2272:            (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
                   2273:                goto out;
                   2274:        if (cipher_authlen(enc->cipher) == 0) {
                   2275:                if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
                   2276:                    (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
                   2277:                    (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
                   2278:                        goto out;
                   2279:        }
                   2280:        if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
                   2281:            (r = sshbuf_put_cstring(b, comp->name)) != 0)
                   2282:                goto out;
                   2283:        r = sshbuf_put_stringb(m, b);
                   2284:  out:
1.221     mmcc     2285:        sshbuf_free(b);
1.201     markus   2286:        return r;
                   2287: }
                   2288:
                   2289: /* serialize packet state into a blob */
                   2290: int
                   2291: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
                   2292: {
                   2293:        struct session_state *state = ssh->state;
1.249     djm      2294:        int r;
1.201     markus   2295:
1.249     djm      2296:        if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
                   2297:            (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
                   2298:            (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
                   2299:            (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
                   2300:            (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
                   2301:            (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
                   2302:            (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
                   2303:            (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
                   2304:            (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
                   2305:            (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
                   2306:            (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
                   2307:            (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255     djm      2308:            (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
                   2309:            (r = sshbuf_put_stringb(m, state->input)) != 0 ||
                   2310:            (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256     djm      2311:                return r;
1.201     markus   2312:
                   2313:        return 0;
                   2314: }
                   2315:
                   2316: /* restore key exchange results from blob for packet state de-serialization */
                   2317: static int
                   2318: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
                   2319: {
                   2320:        struct sshbuf *b = NULL;
                   2321:        struct sshcomp *comp;
                   2322:        struct sshenc *enc;
                   2323:        struct sshmac *mac;
                   2324:        struct newkeys *newkey = NULL;
                   2325:        size_t keylen, ivlen, maclen;
                   2326:        int r;
                   2327:
                   2328:        if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
                   2329:                r = SSH_ERR_ALLOC_FAIL;
                   2330:                goto out;
                   2331:        }
                   2332:        if ((r = sshbuf_froms(m, &b)) != 0)
                   2333:                goto out;
                   2334: #ifdef DEBUG_PK
                   2335:        sshbuf_dump(b, stderr);
                   2336: #endif
                   2337:        enc = &newkey->enc;
                   2338:        mac = &newkey->mac;
                   2339:        comp = &newkey->comp;
                   2340:
                   2341:        if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
                   2342:            (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
                   2343:            (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
                   2344:            (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
                   2345:            (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
                   2346:                goto out;
1.262     djm      2347:        if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
                   2348:                r = SSH_ERR_INVALID_FORMAT;
                   2349:                goto out;
                   2350:        }
1.201     markus   2351:        if (cipher_authlen(enc->cipher) == 0) {
                   2352:                if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
                   2353:                        goto out;
                   2354:                if ((r = mac_setup(mac, mac->name)) != 0)
                   2355:                        goto out;
                   2356:                if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
                   2357:                    (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
                   2358:                        goto out;
                   2359:                if (maclen > mac->key_len) {
                   2360:                        r = SSH_ERR_INVALID_FORMAT;
                   2361:                        goto out;
                   2362:                }
                   2363:                mac->key_len = maclen;
                   2364:        }
                   2365:        if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
                   2366:            (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
                   2367:                goto out;
                   2368:        if (sshbuf_len(b) != 0) {
                   2369:                r = SSH_ERR_INVALID_FORMAT;
                   2370:                goto out;
                   2371:        }
                   2372:        enc->key_len = keylen;
                   2373:        enc->iv_len = ivlen;
                   2374:        ssh->kex->newkeys[mode] = newkey;
                   2375:        newkey = NULL;
                   2376:        r = 0;
                   2377:  out:
1.219     mmcc     2378:        free(newkey);
1.221     mmcc     2379:        sshbuf_free(b);
1.201     markus   2380:        return r;
                   2381: }
                   2382:
                   2383: /* restore kex from blob for packet state de-serialization */
                   2384: static int
                   2385: kex_from_blob(struct sshbuf *m, struct kex **kexp)
                   2386: {
                   2387:        struct kex *kex;
                   2388:        int r;
                   2389:
1.278     djm      2390:        if ((kex = kex_new()) == NULL)
                   2391:                return SSH_ERR_ALLOC_FAIL;
1.299     djm      2392:        if ((r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269     djm      2393:            (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201     markus   2394:            (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269     djm      2395:            (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201     markus   2396:            (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
1.313   ! djm      2397:            (r = sshbuf_get_u32(m, &kex->kex_strict)) != 0 ||
1.201     markus   2398:            (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
                   2399:            (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278     djm      2400:            (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
                   2401:            (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
1.299     djm      2402:            (r = sshbuf_get_stringb(m, kex->session_id)) != 0 ||
1.278     djm      2403:            (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201     markus   2404:                goto out;
                   2405:        kex->server = 1;
                   2406:        kex->done = 1;
                   2407:        r = 0;
                   2408:  out:
                   2409:        if (r != 0 || kexp == NULL) {
1.278     djm      2410:                kex_free(kex);
1.201     markus   2411:                if (kexp != NULL)
                   2412:                        *kexp = NULL;
                   2413:        } else {
1.278     djm      2414:                kex_free(*kexp);
1.201     markus   2415:                *kexp = kex;
                   2416:        }
                   2417:        return r;
                   2418: }
                   2419:
                   2420: /*
                   2421:  * Restore packet state from content of blob 'm' (de-serialization).
                   2422:  * Note that 'm' will be partially consumed on parsing or any other errors.
                   2423:  */
                   2424: int
                   2425: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
                   2426: {
                   2427:        struct session_state *state = ssh->state;
1.254     djm      2428:        const u_char *input, *output;
                   2429:        size_t ilen, olen;
1.201     markus   2430:        int r;
                   2431:
1.249     djm      2432:        if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
                   2433:            (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
                   2434:            (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
                   2435:            (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
                   2436:            (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
                   2437:            (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
                   2438:            (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
                   2439:            (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
                   2440:            (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
                   2441:            (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
                   2442:            (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
                   2443:            (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
                   2444:            (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
                   2445:                return r;
                   2446:        /*
1.296     djm      2447:         * We set the time here so that in post-auth privsep child we
1.249     djm      2448:         * count from the completion of the authentication.
                   2449:         */
                   2450:        state->rekey_time = monotime();
                   2451:        /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
                   2452:        if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
                   2453:            (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
                   2454:                return r;
1.201     markus   2455:
1.239     djm      2456:        if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201     markus   2457:                return r;
                   2458:
                   2459:        sshbuf_reset(state->input);
                   2460:        sshbuf_reset(state->output);
                   2461:        if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
                   2462:            (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
                   2463:            (r = sshbuf_put(state->input, input, ilen)) != 0 ||
                   2464:            (r = sshbuf_put(state->output, output, olen)) != 0)
                   2465:                return r;
                   2466:
                   2467:        if (sshbuf_len(m))
                   2468:                return SSH_ERR_INVALID_FORMAT;
1.297     djm      2469:        debug3_f("done");
1.201     markus   2470:        return 0;
                   2471: }
                   2472:
                   2473: /* NEW API */
                   2474:
                   2475: /* put data to the outgoing packet */
                   2476:
                   2477: int
                   2478: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
                   2479: {
                   2480:        return sshbuf_put(ssh->state->outgoing_packet, v, len);
                   2481: }
                   2482:
                   2483: int
                   2484: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
                   2485: {
                   2486:        return sshbuf_putb(ssh->state->outgoing_packet, b);
                   2487: }
                   2488:
                   2489: int
                   2490: sshpkt_put_u8(struct ssh *ssh, u_char val)
                   2491: {
                   2492:        return sshbuf_put_u8(ssh->state->outgoing_packet, val);
                   2493: }
                   2494:
                   2495: int
                   2496: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
                   2497: {
                   2498:        return sshbuf_put_u32(ssh->state->outgoing_packet, val);
                   2499: }
                   2500:
                   2501: int
                   2502: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
                   2503: {
                   2504:        return sshbuf_put_u64(ssh->state->outgoing_packet, val);
                   2505: }
                   2506:
                   2507: int
                   2508: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
                   2509: {
                   2510:        return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
                   2511: }
                   2512:
                   2513: int
                   2514: sshpkt_put_cstring(struct ssh *ssh, const void *v)
                   2515: {
                   2516:        return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
                   2517: }
                   2518:
                   2519: int
                   2520: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
                   2521: {
                   2522:        return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
                   2523: }
                   2524:
1.211     djm      2525: #ifdef WITH_OPENSSL
1.201     markus   2526: int
                   2527: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
                   2528: {
                   2529:        return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
                   2530: }
                   2531:
                   2532:
                   2533: int
                   2534: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
                   2535: {
                   2536:        return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
                   2537: }
1.211     djm      2538: #endif /* WITH_OPENSSL */
1.201     markus   2539:
                   2540: /* fetch data from the incoming packet */
                   2541:
                   2542: int
                   2543: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
                   2544: {
                   2545:        return sshbuf_get(ssh->state->incoming_packet, valp, len);
                   2546: }
                   2547:
                   2548: int
                   2549: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
                   2550: {
                   2551:        return sshbuf_get_u8(ssh->state->incoming_packet, valp);
                   2552: }
                   2553:
                   2554: int
                   2555: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
                   2556: {
                   2557:        return sshbuf_get_u32(ssh->state->incoming_packet, valp);
                   2558: }
                   2559:
                   2560: int
                   2561: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
                   2562: {
                   2563:        return sshbuf_get_u64(ssh->state->incoming_packet, valp);
                   2564: }
                   2565:
                   2566: int
                   2567: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
                   2568: {
                   2569:        return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
                   2570: }
                   2571:
                   2572: int
                   2573: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
                   2574: {
                   2575:        return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
                   2576: }
                   2577:
                   2578: int
1.264     djm      2579: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
                   2580: {
                   2581:        return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
                   2582: }
                   2583:
                   2584: int
1.201     markus   2585: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
                   2586: {
                   2587:        return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
1.282     djm      2588: }
                   2589:
                   2590: int
                   2591: sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
                   2592: {
                   2593:        return sshbuf_froms(ssh->state->incoming_packet, valp);
1.201     markus   2594: }
                   2595:
1.211     djm      2596: #ifdef WITH_OPENSSL
1.201     markus   2597: int
                   2598: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
                   2599: {
                   2600:        return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
                   2601: }
                   2602:
                   2603: int
1.281     djm      2604: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201     markus   2605: {
1.281     djm      2606:        return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201     markus   2607: }
1.211     djm      2608: #endif /* WITH_OPENSSL */
1.201     markus   2609:
                   2610: int
                   2611: sshpkt_get_end(struct ssh *ssh)
                   2612: {
                   2613:        if (sshbuf_len(ssh->state->incoming_packet) > 0)
                   2614:                return SSH_ERR_UNEXPECTED_TRAILING_DATA;
                   2615:        return 0;
                   2616: }
                   2617:
                   2618: const u_char *
                   2619: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
                   2620: {
                   2621:        if (lenp != NULL)
                   2622:                *lenp = sshbuf_len(ssh->state->incoming_packet);
                   2623:        return sshbuf_ptr(ssh->state->incoming_packet);
                   2624: }
                   2625:
                   2626: /* start a new packet */
                   2627:
                   2628: int
                   2629: sshpkt_start(struct ssh *ssh, u_char type)
                   2630: {
1.249     djm      2631:        u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201     markus   2632:
                   2633:        DBG(debug("packet_start[%d]", type));
1.249     djm      2634:        memset(buf, 0, sizeof(buf));
                   2635:        buf[sizeof(buf) - 1] = type;
1.201     markus   2636:        sshbuf_reset(ssh->state->outgoing_packet);
1.249     djm      2637:        return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201     markus   2638: }
                   2639:
1.242     markus   2640: static int
                   2641: ssh_packet_send_mux(struct ssh *ssh)
                   2642: {
                   2643:        struct session_state *state = ssh->state;
                   2644:        u_char type, *cp;
                   2645:        size_t len;
                   2646:        int r;
                   2647:
                   2648:        if (ssh->kex)
                   2649:                return SSH_ERR_INTERNAL_ERROR;
                   2650:        len = sshbuf_len(state->outgoing_packet);
                   2651:        if (len < 6)
                   2652:                return SSH_ERR_INTERNAL_ERROR;
                   2653:        cp = sshbuf_mutable_ptr(state->outgoing_packet);
                   2654:        type = cp[5];
                   2655:        if (ssh_packet_log_type(type))
1.297     djm      2656:                debug3_f("type %u", type);
1.242     markus   2657:        /* drop everything, but the connection protocol */
                   2658:        if (type >= SSH2_MSG_CONNECTION_MIN &&
                   2659:            type <= SSH2_MSG_CONNECTION_MAX) {
                   2660:                POKE_U32(cp, len - 4);
                   2661:                if ((r = sshbuf_putb(state->output,
                   2662:                    state->outgoing_packet)) != 0)
                   2663:                        return r;
                   2664:                /* sshbuf_dump(state->output, stderr); */
                   2665:        }
                   2666:        sshbuf_reset(state->outgoing_packet);
1.264     djm      2667:        return 0;
                   2668: }
                   2669:
                   2670: /*
                   2671:  * 9.2.  Ignored Data Message
                   2672:  *
                   2673:  *   byte      SSH_MSG_IGNORE
                   2674:  *   string    data
                   2675:  *
                   2676:  * All implementations MUST understand (and ignore) this message at any
                   2677:  * time (after receiving the protocol version). No implementation is
                   2678:  * required to send them. This message can be used as an additional
                   2679:  * protection measure against advanced traffic analysis techniques.
                   2680:  */
                   2681: int
                   2682: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
                   2683: {
                   2684:        u_int32_t rnd = 0;
                   2685:        int r;
                   2686:        u_int i;
                   2687:
                   2688:        if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
                   2689:            (r = sshpkt_put_u32(ssh, nbytes)) != 0)
                   2690:                return r;
                   2691:        for (i = 0; i < nbytes; i++) {
                   2692:                if (i % 4 == 0)
                   2693:                        rnd = arc4random();
                   2694:                if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
                   2695:                        return r;
                   2696:                rnd >>= 8;
                   2697:        }
1.242     markus   2698:        return 0;
                   2699: }
                   2700:
1.201     markus   2701: /* send it */
                   2702:
                   2703: int
                   2704: sshpkt_send(struct ssh *ssh)
                   2705: {
1.242     markus   2706:        if (ssh->state && ssh->state->mux)
                   2707:                return ssh_packet_send_mux(ssh);
1.249     djm      2708:        return ssh_packet_send2(ssh);
1.201     markus   2709: }
                   2710:
                   2711: int
                   2712: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
                   2713: {
                   2714:        char buf[1024];
                   2715:        va_list args;
                   2716:        int r;
                   2717:
                   2718:        va_start(args, fmt);
                   2719:        vsnprintf(buf, sizeof(buf), fmt, args);
                   2720:        va_end(args);
                   2721:
1.313   ! djm      2722:        debug2_f("sending SSH2_MSG_DISCONNECT: %s", buf);
1.249     djm      2723:        if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
                   2724:            (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
                   2725:            (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
                   2726:            (r = sshpkt_put_cstring(ssh, "")) != 0 ||
                   2727:            (r = sshpkt_send(ssh)) != 0)
                   2728:                return r;
1.201     markus   2729:        return 0;
                   2730: }
                   2731:
                   2732: /* roundup current message to pad bytes */
                   2733: int
                   2734: sshpkt_add_padding(struct ssh *ssh, u_char pad)
                   2735: {
                   2736:        ssh->state->extra_pad = pad;
                   2737:        return 0;
1.1       deraadt  2738: }