Annotation of src/usr.bin/ssh/monitor.c, Revision 1.208
1.208 ! naddy 1: /* $OpenBSD: monitor.c,v 1.207 2020/01/23 07:10:22 dtucker Exp $ */
1.1 provos 2: /*
3: * Copyright 2002 Niels Provos <provos@citi.umich.edu>
4: * Copyright 2002 Markus Friedl <markus@openbsd.org>
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26: */
27:
1.67 stevesk 28: #include <sys/types.h>
29: #include <sys/wait.h>
1.79 stevesk 30: #include <sys/socket.h>
1.85 deraadt 31: #include <sys/tree.h>
1.95 djm 32: #include <sys/queue.h>
1.1 provos 33:
1.132 markus 34: #ifdef WITH_OPENSSL
1.78 stevesk 35: #include <openssl/dh.h>
1.132 markus 36: #endif
1.78 stevesk 37:
1.81 stevesk 38: #include <errno.h>
1.80 stevesk 39: #include <fcntl.h>
1.159 djm 40: #include <limits.h>
1.65 stevesk 41: #include <paths.h>
1.114 djm 42: #include <poll.h>
1.78 stevesk 43: #include <pwd.h>
1.68 stevesk 44: #include <signal.h>
1.134 djm 45: #include <stdarg.h>
1.142 millert 46: #include <stdint.h>
1.134 djm 47: #include <stdio.h>
1.84 stevesk 48: #include <stdlib.h>
1.82 stevesk 49: #include <string.h>
1.186 djm 50: #include <unistd.h>
1.1 provos 51:
1.114 djm 52: #include "atomicio.h"
1.85 deraadt 53: #include "xmalloc.h"
1.1 provos 54: #include "ssh.h"
1.185 markus 55: #include "sshkey.h"
1.183 markus 56: #include "sshbuf.h"
1.85 deraadt 57: #include "hostfile.h"
1.1 provos 58: #include "auth.h"
1.85 deraadt 59: #include "cipher.h"
1.1 provos 60: #include "kex.h"
61: #include "dh.h"
62: #include "packet.h"
63: #include "auth-options.h"
64: #include "sshpty.h"
65: #include "channels.h"
66: #include "session.h"
67: #include "sshlogin.h"
68: #include "canohost.h"
69: #include "log.h"
1.135 millert 70: #include "misc.h"
1.1 provos 71: #include "servconf.h"
72: #include "monitor.h"
1.85 deraadt 73: #ifdef GSSAPI
74: #include "ssh-gss.h"
75: #endif
1.1 provos 76: #include "monitor_wrap.h"
77: #include "monitor_fdpass.h"
78: #include "compat.h"
79: #include "ssh2.h"
1.127 markus 80: #include "authfd.h"
1.137 djm 81: #include "match.h"
1.138 djm 82: #include "ssherr.h"
1.203 djm 83: #include "sk-api.h"
1.189 djm 84:
1.46 markus 85: #ifdef GSSAPI
86: static Gssctxt *gsscontext = NULL;
87: #endif
88:
1.1 provos 89: /* Imports */
90: extern ServerOptions options;
91: extern u_int utmp_len;
92: extern u_char session_id[];
1.181 markus 93: extern struct sshbuf *loginmsg;
1.180 djm 94: extern struct sshauthopt *auth_opts; /* XXX move to permanent ssh->authctxt? */
1.1 provos 95:
96: /* State exported from the child */
1.139 markus 97: static struct sshbuf *child_state;
1.1 provos 98:
1.43 markus 99: /* Functions on the monitor that answer unprivileged requests */
1.1 provos 100:
1.191 djm 101: int mm_answer_moduli(struct ssh *, int, struct sshbuf *);
102: int mm_answer_sign(struct ssh *, int, struct sshbuf *);
103: int mm_answer_pwnamallow(struct ssh *, int, struct sshbuf *);
104: int mm_answer_auth2_read_banner(struct ssh *, int, struct sshbuf *);
105: int mm_answer_authserv(struct ssh *, int, struct sshbuf *);
106: int mm_answer_authpassword(struct ssh *, int, struct sshbuf *);
107: int mm_answer_bsdauthquery(struct ssh *, int, struct sshbuf *);
108: int mm_answer_bsdauthrespond(struct ssh *, int, struct sshbuf *);
109: int mm_answer_skeyquery(struct ssh *, int, struct sshbuf *);
110: int mm_answer_skeyrespond(struct ssh *, int, struct sshbuf *);
111: int mm_answer_keyallowed(struct ssh *, int, struct sshbuf *);
112: int mm_answer_keyverify(struct ssh *, int, struct sshbuf *);
113: int mm_answer_pty(struct ssh *, int, struct sshbuf *);
114: int mm_answer_pty_cleanup(struct ssh *, int, struct sshbuf *);
115: int mm_answer_term(struct ssh *, int, struct sshbuf *);
116: int mm_answer_rsa_keyallowed(struct ssh *, int, struct sshbuf *);
117: int mm_answer_rsa_challenge(struct ssh *, int, struct sshbuf *);
118: int mm_answer_rsa_response(struct ssh *, int, struct sshbuf *);
119: int mm_answer_sesskey(struct ssh *, int, struct sshbuf *);
120: int mm_answer_sessid(struct ssh *, int, struct sshbuf *);
1.1 provos 121:
1.46 markus 122: #ifdef GSSAPI
1.191 djm 123: int mm_answer_gss_setup_ctx(struct ssh *, int, struct sshbuf *);
124: int mm_answer_gss_accept_ctx(struct ssh *, int, struct sshbuf *);
125: int mm_answer_gss_userok(struct ssh *, int, struct sshbuf *);
126: int mm_answer_gss_checkmic(struct ssh *, int, struct sshbuf *);
1.46 markus 127: #endif
1.25 itojun 128:
1.1 provos 129: static Authctxt *authctxt;
1.132 markus 130:
1.1 provos 131: /* local state for key verify */
132: static u_char *key_blob = NULL;
1.183 markus 133: static size_t key_bloblen = 0;
1.1 provos 134: static int key_blobtype = MM_NOKEY;
1.180 djm 135: static struct sshauthopt *key_opts = NULL;
1.26 markus 136: static char *hostbased_cuser = NULL;
137: static char *hostbased_chost = NULL;
1.1 provos 138: static char *auth_method = "unknown";
1.119 djm 139: static char *auth_submethod = NULL;
1.44 markus 140: static u_int session_id2_len = 0;
1.13 markus 141: static u_char *session_id2 = NULL;
1.40 markus 142: static pid_t monitor_child_pid;
1.1 provos 143:
144: struct mon_table {
145: enum monitor_reqtype type;
146: int flags;
1.191 djm 147: int (*f)(struct ssh *, int, struct sshbuf *);
1.1 provos 148: };
149:
150: #define MON_ISAUTH 0x0004 /* Required for Authentication */
151: #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
152: #define MON_ONCE 0x0010 /* Disable after calling */
1.77 dtucker 153: #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
1.1 provos 154:
155: #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
156:
157: #define MON_PERMIT 0x1000 /* Request is permitted */
158:
1.191 djm 159: static int monitor_read(struct ssh *, struct monitor *, struct mon_table *,
160: struct mon_table **);
161: static int monitor_read_log(struct monitor *);
162:
1.1 provos 163: struct mon_table mon_dispatch_proto20[] = {
1.132 markus 164: #ifdef WITH_OPENSSL
1.1 provos 165: {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
1.132 markus 166: #endif
1.1 provos 167: {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
168: {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
169: {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
1.10 djm 170: {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
1.1 provos 171: {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
172: {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
1.66 stevesk 173: {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
1.1 provos 174: {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
175: {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
1.46 markus 176: #ifdef GSSAPI
177: {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
1.165 djm 178: {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
179: {MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok},
180: {MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic},
1.46 markus 181: #endif
1.1 provos 182: {0, 0, NULL}
183: };
184:
185: struct mon_table mon_dispatch_postauth20[] = {
1.132 markus 186: #ifdef WITH_OPENSSL
1.1 provos 187: {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
1.132 markus 188: #endif
1.1 provos 189: {MONITOR_REQ_SIGN, 0, mm_answer_sign},
190: {MONITOR_REQ_PTY, 0, mm_answer_pty},
191: {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
192: {MONITOR_REQ_TERM, 0, mm_answer_term},
193: {0, 0, NULL}
194: };
195:
196: struct mon_table *mon_dispatch;
197:
198: /* Specifies if a certain message is allowed at the moment */
199: static void
200: monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
201: {
202: while (ent->f != NULL) {
203: if (ent->type == type) {
204: ent->flags &= ~MON_PERMIT;
205: ent->flags |= permit ? MON_PERMIT : 0;
206: return;
207: }
208: ent++;
209: }
210: }
211:
212: static void
213: monitor_permit_authentications(int permit)
214: {
215: struct mon_table *ent = mon_dispatch;
216:
217: while (ent->f != NULL) {
218: if (ent->flags & MON_AUTH) {
219: ent->flags &= ~MON_PERMIT;
220: ent->flags |= permit ? MON_PERMIT : 0;
221: }
222: ent++;
223: }
224: }
225:
1.50 markus 226: void
1.191 djm 227: monitor_child_preauth(struct ssh *ssh, struct monitor *pmonitor)
1.1 provos 228: {
229: struct mon_table *ent;
1.119 djm 230: int authenticated = 0, partial = 0;
1.1 provos 231:
232: debug3("preauth child monitor started");
233:
1.179 tb 234: if (pmonitor->m_recvfd >= 0)
235: close(pmonitor->m_recvfd);
236: if (pmonitor->m_log_sendfd >= 0)
237: close(pmonitor->m_log_sendfd);
1.114 djm 238: pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
239:
1.191 djm 240: authctxt = (Authctxt *)ssh->authctxt;
1.50 markus 241: memset(authctxt, 0, sizeof(*authctxt));
1.180 djm 242: ssh->authctxt = authctxt;
1.50 markus 243:
1.162 markus 244: mon_dispatch = mon_dispatch_proto20;
245: /* Permit requests for moduli and signatures */
246: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
247: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
1.1 provos 248:
249: /* The first few requests do not require asynchronous access */
250: while (!authenticated) {
1.119 djm 251: partial = 0;
1.77 dtucker 252: auth_method = "unknown";
1.119 djm 253: auth_submethod = NULL;
1.172 djm 254: auth2_authctxt_reset_info(authctxt);
255:
1.191 djm 256: authenticated = (monitor_read(ssh, pmonitor,
257: mon_dispatch, &ent) == 1);
1.118 djm 258:
259: /* Special handling for multiple required authentications */
260: if (options.num_auth_methods != 0) {
261: if (authenticated &&
262: !auth2_update_methods_lists(authctxt,
1.122 markus 263: auth_method, auth_submethod)) {
1.118 djm 264: debug3("%s: method %s: partial", __func__,
265: auth_method);
266: authenticated = 0;
1.119 djm 267: partial = 1;
1.118 djm 268: }
269: }
270:
1.1 provos 271: if (authenticated) {
272: if (!(ent->flags & MON_AUTHDECIDE))
273: fatal("%s: unexpected authentication from %d",
1.14 markus 274: __func__, ent->type);
1.1 provos 275: if (authctxt->pw->pw_uid == 0 &&
1.180 djm 276: !auth_root_allowed(ssh, auth_method))
1.1 provos 277: authenticated = 0;
278: }
1.77 dtucker 279: if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
1.190 djm 280: auth_log(ssh, authenticated, partial,
1.125 djm 281: auth_method, auth_submethod);
1.150 djm 282: if (!partial && !authenticated)
1.1 provos 283: authctxt->failures++;
1.172 djm 284: if (authenticated || partial) {
285: auth2_update_session_info(authctxt,
286: auth_method, auth_submethod);
287: }
1.1 provos 288: }
289: }
290:
291: if (!authctxt->valid)
1.14 markus 292: fatal("%s: authenticated invalid user", __func__);
1.77 dtucker 293: if (strcmp(auth_method, "unknown") == 0)
294: fatal("%s: authentication method name unknown", __func__);
1.1 provos 295:
296: debug("%s: %s has been authenticated by privileged process",
1.14 markus 297: __func__, authctxt->user);
1.180 djm 298: ssh->authctxt = NULL;
1.167 djm 299: ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user);
1.1 provos 300:
1.192 djm 301: mm_get_keystate(ssh, pmonitor);
1.120 markus 302:
303: /* Drain any buffered messages from the child */
304: while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
305: ;
1.114 djm 306:
1.179 tb 307: if (pmonitor->m_recvfd >= 0)
308: close(pmonitor->m_recvfd);
309: if (pmonitor->m_log_sendfd >= 0)
310: close(pmonitor->m_log_sendfd);
1.114 djm 311: pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
1.1 provos 312: }
313:
1.40 markus 314: static void
315: monitor_set_child_handler(pid_t pid)
316: {
317: monitor_child_pid = pid;
318: }
319:
320: static void
1.59 avsm 321: monitor_child_handler(int sig)
1.40 markus 322: {
1.59 avsm 323: kill(monitor_child_pid, sig);
1.40 markus 324: }
325:
1.1 provos 326: void
1.191 djm 327: monitor_child_postauth(struct ssh *ssh, struct monitor *pmonitor)
1.1 provos 328: {
1.114 djm 329: close(pmonitor->m_recvfd);
330: pmonitor->m_recvfd = -1;
331:
1.40 markus 332: monitor_set_child_handler(pmonitor->m_pid);
1.207 dtucker 333: ssh_signal(SIGHUP, &monitor_child_handler);
334: ssh_signal(SIGTERM, &monitor_child_handler);
335: ssh_signal(SIGINT, &monitor_child_handler);
1.40 markus 336:
1.162 markus 337: mon_dispatch = mon_dispatch_postauth20;
338:
339: /* Permit requests for moduli and signatures */
340: monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
341: monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
342: monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
1.1 provos 343:
1.180 djm 344: if (auth_opts->permit_pty_flag) {
1.1 provos 345: monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
346: monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
347: }
348:
349: for (;;)
1.191 djm 350: monitor_read(ssh, pmonitor, mon_dispatch, NULL);
1.1 provos 351: }
352:
1.114 djm 353: static int
354: monitor_read_log(struct monitor *pmonitor)
355: {
1.183 markus 356: struct sshbuf *logmsg;
1.114 djm 357: u_int len, level;
358: char *msg;
1.183 markus 359: u_char *p;
360: int r;
1.114 djm 361:
1.183 markus 362: if ((logmsg = sshbuf_new()) == NULL)
363: fatal("%s: sshbuf_new", __func__);
1.114 djm 364:
365: /* Read length */
1.183 markus 366: if ((r = sshbuf_reserve(logmsg, 4, &p)) != 0)
367: fatal("%s: reserve: %s", __func__, ssh_err(r));
368: if (atomicio(read, pmonitor->m_log_recvfd, p, 4) != 4) {
1.114 djm 369: if (errno == EPIPE) {
1.183 markus 370: sshbuf_free(logmsg);
1.114 djm 371: debug("%s: child log fd closed", __func__);
372: close(pmonitor->m_log_recvfd);
373: pmonitor->m_log_recvfd = -1;
374: return -1;
375: }
376: fatal("%s: log fd read: %s", __func__, strerror(errno));
377: }
1.183 markus 378: if ((r = sshbuf_get_u32(logmsg, &len)) != 0)
379: fatal("%s: get len: %s", __func__, ssh_err(r));
1.114 djm 380: if (len <= 4 || len > 8192)
381: fatal("%s: invalid log message length %u", __func__, len);
382:
383: /* Read severity, message */
1.183 markus 384: sshbuf_reset(logmsg);
385: if ((r = sshbuf_reserve(logmsg, len, &p)) != 0)
386: fatal("%s: reserve: %s", __func__, ssh_err(r));
387: if (atomicio(read, pmonitor->m_log_recvfd, p, len) != len)
1.114 djm 388: fatal("%s: log fd read: %s", __func__, strerror(errno));
1.183 markus 389: if ((r = sshbuf_get_u32(logmsg, &level)) != 0 ||
390: (r = sshbuf_get_cstring(logmsg, &msg, NULL)) != 0)
391: fatal("%s: decode: %s", __func__, ssh_err(r));
1.114 djm 392:
393: /* Log it */
394: if (log_level_name(level) == NULL)
395: fatal("%s: invalid log level %u (corrupted message?)",
396: __func__, level);
397: do_log2(level, "%s [preauth]", msg);
398:
1.183 markus 399: sshbuf_free(logmsg);
1.124 djm 400: free(msg);
1.114 djm 401:
402: return 0;
403: }
404:
1.191 djm 405: static int
406: monitor_read(struct ssh *ssh, struct monitor *pmonitor, struct mon_table *ent,
1.1 provos 407: struct mon_table **pent)
408: {
1.183 markus 409: struct sshbuf *m;
410: int r, ret;
1.1 provos 411: u_char type;
1.114 djm 412: struct pollfd pfd[2];
413:
414: for (;;) {
1.130 tedu 415: memset(&pfd, 0, sizeof(pfd));
1.114 djm 416: pfd[0].fd = pmonitor->m_sendfd;
417: pfd[0].events = POLLIN;
418: pfd[1].fd = pmonitor->m_log_recvfd;
419: pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
1.115 djm 420: if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
421: if (errno == EINTR || errno == EAGAIN)
422: continue;
1.114 djm 423: fatal("%s: poll: %s", __func__, strerror(errno));
1.115 djm 424: }
1.114 djm 425: if (pfd[1].revents) {
426: /*
427: * Drain all log messages before processing next
428: * monitor request.
429: */
430: monitor_read_log(pmonitor);
431: continue;
432: }
433: if (pfd[0].revents)
434: break; /* Continues below */
435: }
1.1 provos 436:
1.183 markus 437: if ((m = sshbuf_new()) == NULL)
438: fatal("%s: sshbuf_new", __func__);
1.1 provos 439:
1.183 markus 440: mm_request_receive(pmonitor->m_sendfd, m);
441: if ((r = sshbuf_get_u8(m, &type)) != 0)
442: fatal("%s: decode: %s", __func__, ssh_err(r));
1.1 provos 443:
1.14 markus 444: debug3("%s: checking request %d", __func__, type);
1.1 provos 445:
446: while (ent->f != NULL) {
447: if (ent->type == type)
448: break;
449: ent++;
450: }
451:
452: if (ent->f != NULL) {
453: if (!(ent->flags & MON_PERMIT))
1.14 markus 454: fatal("%s: unpermitted request %d", __func__,
1.1 provos 455: type);
1.191 djm 456: ret = (*ent->f)(ssh, pmonitor->m_sendfd, m);
1.183 markus 457: sshbuf_free(m);
1.1 provos 458:
459: /* The child may use this request only once, disable it */
460: if (ent->flags & MON_ONCE) {
1.14 markus 461: debug2("%s: %d used once, disabling now", __func__,
1.1 provos 462: type);
463: ent->flags &= ~MON_PERMIT;
464: }
465:
466: if (pent != NULL)
467: *pent = ent;
1.3 markus 468:
1.1 provos 469: return ret;
470: }
471:
1.14 markus 472: fatal("%s: unsupported request: %d", __func__, type);
1.1 provos 473:
474: /* NOTREACHED */
475: return (-1);
476: }
477:
478: /* allowed key state */
479: static int
1.203 djm 480: monitor_allowed_key(const u_char *blob, u_int bloblen)
1.1 provos 481: {
482: /* make sure key is allowed */
483: if (key_blob == NULL || key_bloblen != bloblen ||
1.108 djm 484: timingsafe_bcmp(key_blob, blob, key_bloblen))
1.1 provos 485: return (0);
486: return (1);
487: }
488:
489: static void
490: monitor_reset_key_state(void)
491: {
492: /* reset state */
1.124 djm 493: free(key_blob);
494: free(hostbased_cuser);
495: free(hostbased_chost);
1.180 djm 496: sshauthopt_free(key_opts);
1.1 provos 497: key_blob = NULL;
498: key_bloblen = 0;
499: key_blobtype = MM_NOKEY;
1.180 djm 500: key_opts = NULL;
1.1 provos 501: hostbased_cuser = NULL;
502: hostbased_chost = NULL;
503: }
504:
1.132 markus 505: #ifdef WITH_OPENSSL
1.1 provos 506: int
1.191 djm 507: mm_answer_moduli(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 508: {
509: DH *dh;
1.187 djm 510: const BIGNUM *dh_p, *dh_g;
1.183 markus 511: int r;
512: u_int min, want, max;
1.1 provos 513:
1.183 markus 514: if ((r = sshbuf_get_u32(m, &min)) != 0 ||
515: (r = sshbuf_get_u32(m, &want)) != 0 ||
516: (r = sshbuf_get_u32(m, &max)) != 0)
517: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 518:
519: debug3("%s: got parameters: %d %d %d",
1.14 markus 520: __func__, min, want, max);
1.1 provos 521: /* We need to check here, too, in case the child got corrupted */
522: if (max < min || want < min || max < want)
523: fatal("%s: bad parameters: %d %d %d",
1.14 markus 524: __func__, min, want, max);
1.1 provos 525:
1.183 markus 526: sshbuf_reset(m);
1.1 provos 527:
528: dh = choose_dh(min, want, max);
529: if (dh == NULL) {
1.183 markus 530: if ((r = sshbuf_put_u8(m, 0)) != 0)
531: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 532: return (0);
533: } else {
534: /* Send first bignum */
1.187 djm 535: DH_get0_pqg(dh, &dh_p, NULL, &dh_g);
1.183 markus 536: if ((r = sshbuf_put_u8(m, 1)) != 0 ||
1.187 djm 537: (r = sshbuf_put_bignum2(m, dh_p)) != 0 ||
538: (r = sshbuf_put_bignum2(m, dh_g)) != 0)
1.183 markus 539: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.3 markus 540:
1.1 provos 541: DH_free(dh);
542: }
1.59 avsm 543: mm_request_send(sock, MONITOR_ANS_MODULI, m);
1.1 provos 544: return (0);
545: }
1.132 markus 546: #endif
1.1 provos 547:
548: int
1.191 djm 549: mm_answer_sign(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 550: {
1.138 djm 551: extern int auth_sock; /* XXX move to state struct? */
552: struct sshkey *key;
1.157 djm 553: struct sshbuf *sigbuf = NULL;
554: u_char *p = NULL, *signature = NULL;
555: char *alg = NULL;
1.155 markus 556: size_t datlen, siglen, alglen;
1.159 djm 557: int r, is_proof = 0;
1.185 markus 558: u_int keyid, compat;
1.145 djm 559: const char proof_req[] = "hostkeys-prove-00@openssh.com";
1.3 markus 560:
1.14 markus 561: debug3("%s", __func__);
1.1 provos 562:
1.138 djm 563: if ((r = sshbuf_get_u32(m, &keyid)) != 0 ||
1.155 markus 564: (r = sshbuf_get_string(m, &p, &datlen)) != 0 ||
1.185 markus 565: (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0 ||
566: (r = sshbuf_get_u32(m, &compat)) != 0)
1.138 djm 567: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.159 djm 568: if (keyid > INT_MAX)
569: fatal("%s: invalid key ID", __func__);
1.1 provos 570:
1.69 djm 571: /*
1.110 djm 572: * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
573: * SHA384 (48 bytes) and SHA512 (64 bytes).
1.144 djm 574: *
575: * Otherwise, verify the signature request is for a hostkey
576: * proof.
577: *
578: * XXX perform similar check for KEX signature requests too?
579: * it's not trivial, since what is signed is the hash, rather
580: * than the full kex structure...
1.69 djm 581: */
1.144 djm 582: if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) {
583: /*
584: * Construct expected hostkey proof and compare it to what
585: * the client sent us.
586: */
587: if (session_id2_len == 0) /* hostkeys is never first */
588: fatal("%s: bad data length: %zu", __func__, datlen);
589: if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL)
590: fatal("%s: no hostkey for index %d", __func__, keyid);
591: if ((sigbuf = sshbuf_new()) == NULL)
592: fatal("%s: sshbuf_new", __func__);
1.145 djm 593: if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 ||
594: (r = sshbuf_put_string(sigbuf, session_id2,
1.152 jsg 595: session_id2_len)) != 0 ||
1.144 djm 596: (r = sshkey_puts(key, sigbuf)) != 0)
597: fatal("%s: couldn't prepare private key "
598: "proof buffer: %s", __func__, ssh_err(r));
599: if (datlen != sshbuf_len(sigbuf) ||
600: memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0)
601: fatal("%s: bad data length: %zu, hostkey proof len %zu",
602: __func__, datlen, sshbuf_len(sigbuf));
603: sshbuf_free(sigbuf);
604: is_proof = 1;
605: }
1.1 provos 606:
1.13 markus 607: /* save session id, it will be passed on the first call */
608: if (session_id2_len == 0) {
609: session_id2_len = datlen;
610: session_id2 = xmalloc(session_id2_len);
611: memcpy(session_id2, p, session_id2_len);
612: }
613:
1.127 markus 614: if ((key = get_hostkey_by_index(keyid)) != NULL) {
1.155 markus 615: if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg,
1.206 djm 616: options.sk_provider, compat)) != 0)
1.138 djm 617: fatal("%s: sshkey_sign failed: %s",
618: __func__, ssh_err(r));
1.144 djm 619: } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL &&
1.138 djm 620: auth_sock > 0) {
621: if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen,
1.185 markus 622: p, datlen, alg, compat)) != 0) {
1.138 djm 623: fatal("%s: ssh_agent_sign failed: %s",
624: __func__, ssh_err(r));
625: }
1.127 markus 626: } else
1.14 markus 627: fatal("%s: no hostkey from index %d", __func__, keyid);
1.1 provos 628:
1.144 djm 629: debug3("%s: %s signature %p(%zu)", __func__,
1.199 djm 630: is_proof ? "hostkey proof" : "KEX", signature, siglen);
1.1 provos 631:
1.138 djm 632: sshbuf_reset(m);
633: if ((r = sshbuf_put_string(m, signature, siglen)) != 0)
634: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 635:
1.157 djm 636: free(alg);
1.124 djm 637: free(p);
638: free(signature);
1.1 provos 639:
1.59 avsm 640: mm_request_send(sock, MONITOR_ANS_SIGN, m);
1.1 provos 641:
642: /* Turn on permissions for getpwnam */
643: monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
644:
645: return (0);
646: }
647:
648: /* Retrieves the password entry and also checks if the user is permitted */
649:
650: int
1.191 djm 651: mm_answer_pwnamallow(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 652: {
1.60 dtucker 653: char *username;
1.1 provos 654: struct passwd *pwent;
1.183 markus 655: int r, allowed = 0;
1.113 djm 656: u_int i;
1.3 markus 657:
1.14 markus 658: debug3("%s", __func__);
1.1 provos 659:
660: if (authctxt->attempt++ != 0)
1.14 markus 661: fatal("%s: multiple attempts for getpwnam", __func__);
1.1 provos 662:
1.183 markus 663: if ((r = sshbuf_get_cstring(m, &username, NULL)) != 0)
664: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 665:
1.190 djm 666: pwent = getpwnamallow(ssh, username);
1.1 provos 667:
1.60 dtucker 668: authctxt->user = xstrdup(username);
669: setproctitle("%s [priv]", pwent ? username : "unknown");
1.124 djm 670: free(username);
1.1 provos 671:
1.183 markus 672: sshbuf_reset(m);
1.1 provos 673:
674: if (pwent == NULL) {
1.183 markus 675: if ((r = sshbuf_put_u8(m, 0)) != 0)
676: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.53 djm 677: authctxt->pw = fakepw();
1.1 provos 678: goto out;
679: }
680:
681: allowed = 1;
1.4 markus 682: authctxt->pw = pwent;
1.1 provos 683: authctxt->valid = 1;
684:
1.183 markus 685: /* XXX don't sent pwent to unpriv; send fake class/dir/shell too */
686: if ((r = sshbuf_put_u8(m, 1)) != 0 ||
687: (r = sshbuf_put_string(m, pwent, sizeof(*pwent))) != 0 ||
688: (r = sshbuf_put_cstring(m, pwent->pw_name)) != 0 ||
689: (r = sshbuf_put_cstring(m, "*")) != 0 ||
690: (r = sshbuf_put_cstring(m, pwent->pw_gecos)) != 0 ||
691: (r = sshbuf_put_cstring(m, pwent->pw_class)) != 0 ||
692: (r = sshbuf_put_cstring(m, pwent->pw_dir)) != 0 ||
693: (r = sshbuf_put_cstring(m, pwent->pw_shell)) != 0)
694: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.94 dtucker 695:
696: out:
1.167 djm 697: ssh_packet_set_log_preamble(ssh, "%suser %s",
698: authctxt->valid ? "authenticating" : "invalid ", authctxt->user);
1.183 markus 699: if ((r = sshbuf_put_string(m, &options, sizeof(options))) != 0)
700: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.112 djm 701:
702: #define M_CP_STROPT(x) do { \
1.183 markus 703: if (options.x != NULL) { \
704: if ((r = sshbuf_put_cstring(m, options.x)) != 0) \
705: fatal("%s: buffer error: %s", \
706: __func__, ssh_err(r)); \
707: } \
1.112 djm 708: } while (0)
1.113 djm 709: #define M_CP_STRARRAYOPT(x, nx) do { \
1.183 markus 710: for (i = 0; i < options.nx; i++) { \
711: if ((r = sshbuf_put_cstring(m, options.x[i])) != 0) \
712: fatal("%s: buffer error: %s", \
713: __func__, ssh_err(r)); \
714: } \
1.113 djm 715: } while (0)
1.112 djm 716: /* See comment in servconf.h */
717: COPY_MATCH_STRING_OPTS();
718: #undef M_CP_STROPT
1.113 djm 719: #undef M_CP_STRARRAYOPT
1.118 djm 720:
721: /* Create valid auth method lists */
1.162 markus 722: if (auth2_setup_methods_lists(authctxt) != 0) {
1.118 djm 723: /*
724: * The monitor will continue long enough to let the child
725: * run to it's packet_disconnect(), but it must not allow any
726: * authentication to succeed.
727: */
728: debug("%s: no valid authentication method lists", __func__);
729: }
730:
1.14 markus 731: debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
1.59 avsm 732: mm_request_send(sock, MONITOR_ANS_PWNAM, m);
1.1 provos 733:
1.162 markus 734: /* Allow service/style information on the auth context */
735: monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
736: monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
1.10 djm 737:
738: return (0);
739: }
740:
1.191 djm 741: int mm_answer_auth2_read_banner(struct ssh *ssh, int sock, struct sshbuf *m)
1.10 djm 742: {
743: char *banner;
1.183 markus 744: int r;
1.10 djm 745:
1.183 markus 746: sshbuf_reset(m);
1.10 djm 747: banner = auth2_read_banner();
1.183 markus 748: if ((r = sshbuf_put_cstring(m, banner != NULL ? banner : "")) != 0)
749: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.59 avsm 750: mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
1.124 djm 751: free(banner);
1.1 provos 752:
753: return (0);
754: }
755:
756: int
1.191 djm 757: mm_answer_authserv(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 758: {
1.183 markus 759: int r;
760:
1.1 provos 761: monitor_permit_authentications(1);
762:
1.183 markus 763: if ((r = sshbuf_get_cstring(m, &authctxt->service, NULL)) != 0 ||
764: (r = sshbuf_get_cstring(m, &authctxt->style, NULL)) != 0)
765: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.6 stevesk 766: debug3("%s: service=%s, style=%s",
1.14 markus 767: __func__, authctxt->service, authctxt->style);
1.6 stevesk 768:
1.1 provos 769: if (strlen(authctxt->style) == 0) {
1.124 djm 770: free(authctxt->style);
1.1 provos 771: authctxt->style = NULL;
772: }
773:
774: return (0);
775: }
776:
777: int
1.191 djm 778: mm_answer_authpassword(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 779: {
780: static int call_count;
781: char *passwd;
1.183 markus 782: int r, authenticated;
783: size_t plen;
1.1 provos 784:
1.164 djm 785: if (!options.password_authentication)
786: fatal("%s: password authentication not enabled", __func__);
1.183 markus 787: if ((r = sshbuf_get_cstring(m, &passwd, &plen)) != 0)
788: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 789: /* Only authenticate if the context is valid */
1.12 markus 790: authenticated = options.password_authentication &&
1.180 djm 791: auth_password(ssh, passwd);
1.183 markus 792: explicit_bzero(passwd, plen);
1.124 djm 793: free(passwd);
1.1 provos 794:
1.183 markus 795: sshbuf_reset(m);
796: if ((r = sshbuf_put_u32(m, authenticated)) != 0)
797: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 798:
1.14 markus 799: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 800: mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
1.1 provos 801:
802: call_count++;
803: if (plen == 0 && call_count == 1)
804: auth_method = "none";
805: else
806: auth_method = "password";
807:
808: /* Causes monitor loop to terminate if authenticated */
809: return (authenticated);
810: }
811:
812: int
1.191 djm 813: mm_answer_bsdauthquery(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 814: {
815: char *name, *infotxt;
1.183 markus 816: u_int numprompts, *echo_on, success;
1.1 provos 817: char **prompts;
1.183 markus 818: int r;
1.1 provos 819:
1.164 djm 820: if (!options.kbd_interactive_authentication)
821: fatal("%s: kbd-int authentication not enabled", __func__);
1.31 markus 822: success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
823: &prompts, &echo_on) < 0 ? 0 : 1;
1.1 provos 824:
1.183 markus 825: sshbuf_reset(m);
826: if ((r = sshbuf_put_u32(m, success)) != 0)
827: fatal("%s: buffer error: %s", __func__, ssh_err(r));
828: if (success) {
829: if ((r = sshbuf_put_cstring(m, prompts[0])) != 0)
830: fatal("%s: buffer error: %s", __func__, ssh_err(r));
831: }
1.1 provos 832:
1.31 markus 833: debug3("%s: sending challenge success: %u", __func__, success);
1.59 avsm 834: mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
1.1 provos 835:
1.31 markus 836: if (success) {
1.124 djm 837: free(name);
838: free(infotxt);
839: free(prompts);
840: free(echo_on);
1.1 provos 841: }
842:
843: return (0);
844: }
845:
846: int
1.191 djm 847: mm_answer_bsdauthrespond(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 848: {
849: char *response;
1.183 markus 850: int r, authok;
1.1 provos 851:
1.164 djm 852: if (!options.kbd_interactive_authentication)
853: fatal("%s: kbd-int authentication not enabled", __func__);
1.154 mmcc 854: if (authctxt->as == NULL)
1.14 markus 855: fatal("%s: no bsd auth session", __func__);
1.1 provos 856:
1.183 markus 857: if ((r = sshbuf_get_cstring(m, &response, NULL)) != 0)
858: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.12 markus 859: authok = options.challenge_response_authentication &&
860: auth_userresponse(authctxt->as, response, 0);
1.1 provos 861: authctxt->as = NULL;
1.14 markus 862: debug3("%s: <%s> = <%d>", __func__, response, authok);
1.124 djm 863: free(response);
1.1 provos 864:
1.183 markus 865: sshbuf_reset(m);
866: if ((r = sshbuf_put_u32(m, authok)) != 0)
867: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 868:
1.14 markus 869: debug3("%s: sending authenticated: %d", __func__, authok);
1.59 avsm 870: mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
1.1 provos 871:
1.162 markus 872: auth_method = "keyboard-interactive";
873: auth_submethod = "bsdauth";
1.1 provos 874:
875: return (authok != 0);
876: }
877:
1.188 djm 878: /*
879: * Check that the key type appears in the supplied pattern list, ignoring
880: * mismatches in the signature algorithm. (Signature algorithm checks are
881: * performed in the unprivileged authentication code).
882: * Returns 1 on success, 0 otherwise.
883: */
884: static int
885: key_base_type_match(const char *method, const struct sshkey *key,
886: const char *list)
887: {
888: char *s, *l, *ol = xstrdup(list);
889: int found = 0;
890:
891: l = ol;
892: for ((s = strsep(&l, ",")); s && *s != '\0'; (s = strsep(&l, ","))) {
893: if (sshkey_type_from_name(s) == key->type) {
894: found = 1;
895: break;
896: }
897: }
898: if (!found) {
899: error("%s key type %s is not in permitted list %s", method,
900: sshkey_ssh_name(key), list);
901: }
902:
903: free(ol);
904: return found;
905: }
906:
1.1 provos 907: int
1.191 djm 908: mm_answer_keyallowed(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 909: {
1.183 markus 910: struct sshkey *key = NULL;
1.26 markus 911: char *cuser, *chost;
1.183 markus 912: u_int pubkey_auth_attempt;
1.1 provos 913: enum mm_keytype type = 0;
1.180 djm 914: int r, allowed = 0;
915: struct sshauthopt *opts = NULL;
1.1 provos 916:
1.14 markus 917: debug3("%s entering", __func__);
1.183 markus 918: if ((r = sshbuf_get_u32(m, &type)) != 0 ||
919: (r = sshbuf_get_cstring(m, &cuser, NULL)) != 0 ||
920: (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
921: (r = sshkey_froms(m, &key)) != 0 ||
922: (r = sshbuf_get_u32(m, &pubkey_auth_attempt)) != 0)
923: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 924:
1.14 markus 925: debug3("%s: key_from_blob: %p", __func__, key);
1.1 provos 926:
1.51 djm 927: if (key != NULL && authctxt->valid) {
1.137 djm 928: /* These should not make it past the privsep child */
1.185 markus 929: if (sshkey_type_plain(key->type) == KEY_RSA &&
1.137 djm 930: (datafellows & SSH_BUG_RSASIGMD5) != 0)
931: fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__);
932:
1.63 deraadt 933: switch (type) {
1.1 provos 934: case MM_USERKEY:
1.77 dtucker 935: auth_method = "publickey";
1.180 djm 936: if (!options.pubkey_authentication)
937: break;
938: if (auth2_key_already_used(authctxt, key))
939: break;
1.188 djm 940: if (!key_base_type_match(auth_method, key,
941: options.pubkey_key_types))
1.180 djm 942: break;
943: allowed = user_key_allowed(ssh, authctxt->pw, key,
944: pubkey_auth_attempt, &opts);
1.1 provos 945: break;
946: case MM_HOSTKEY:
1.180 djm 947: auth_method = "hostbased";
948: if (!options.hostbased_authentication)
949: break;
950: if (auth2_key_already_used(authctxt, key))
951: break;
1.188 djm 952: if (!key_base_type_match(auth_method, key,
953: options.hostbased_key_types))
1.180 djm 954: break;
1.192 djm 955: allowed = hostbased_key_allowed(ssh, authctxt->pw,
1.1 provos 956: cuser, chost, key);
1.172 djm 957: auth2_record_info(authctxt,
1.126 djm 958: "client user \"%.100s\", client host \"%.100s\"",
959: cuser, chost);
1.1 provos 960: break;
961: default:
1.14 markus 962: fatal("%s: unknown key type %d", __func__, type);
1.1 provos 963: break;
964: }
1.33 markus 965: }
1.161 djm 966:
1.180 djm 967: debug3("%s: %s authentication%s: %s key is %s", __func__,
968: auth_method, pubkey_auth_attempt ? "" : " test",
969: (key == NULL || !authctxt->valid) ? "invalid" : sshkey_type(key),
970: allowed ? "allowed" : "not allowed");
1.161 djm 971:
1.172 djm 972: auth2_record_key(authctxt, 0, key);
1.1 provos 973:
974: /* clear temporarily storage (used by verify) */
975: monitor_reset_key_state();
976:
977: if (allowed) {
978: /* Save temporarily for comparison in verify */
1.183 markus 979: if ((r = sshkey_to_blob(key, &key_blob, &key_bloblen)) != 0)
980: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 981: key_blobtype = type;
1.180 djm 982: key_opts = opts;
1.1 provos 983: hostbased_cuser = cuser;
984: hostbased_chost = chost;
1.72 djm 985: } else {
1.77 dtucker 986: /* Log failed attempt */
1.190 djm 987: auth_log(ssh, 0, 0, auth_method, NULL);
1.124 djm 988: free(cuser);
989: free(chost);
1.1 provos 990: }
1.183 markus 991: sshkey_free(key);
1.1 provos 992:
1.183 markus 993: sshbuf_reset(m);
994: if ((r = sshbuf_put_u32(m, allowed)) != 0)
995: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.180 djm 996: if (opts != NULL && (r = sshauthopt_serialise(opts, m, 1)) != 0)
997: fatal("%s: sshauthopt_serialise: %s", __func__, ssh_err(r));
998: mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1.1 provos 999:
1.180 djm 1000: if (!allowed)
1001: sshauthopt_free(opts);
1.1 provos 1002:
1003: return (0);
1004: }
1005:
1006: static int
1.203 djm 1007: monitor_valid_userblob(const u_char *data, u_int datalen)
1.1 provos 1008: {
1.183 markus 1009: struct sshbuf *b;
1010: const u_char *p;
1.159 djm 1011: char *userstyle, *cp;
1.183 markus 1012: size_t len;
1013: u_char type;
1014: int r, fail = 0;
1.1 provos 1015:
1.203 djm 1016: if ((b = sshbuf_from(data, datalen)) == NULL)
1017: fatal("%s: sshbuf_from", __func__);
1.3 markus 1018:
1.1 provos 1019: if (datafellows & SSH_OLD_SESSIONID) {
1.183 markus 1020: p = sshbuf_ptr(b);
1021: len = sshbuf_len(b);
1.13 markus 1022: if ((session_id2 == NULL) ||
1023: (len < session_id2_len) ||
1.108 djm 1024: (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1.13 markus 1025: fail++;
1.183 markus 1026: if ((r = sshbuf_consume(b, session_id2_len)) != 0)
1027: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 1028: } else {
1.183 markus 1029: if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
1030: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.13 markus 1031: if ((session_id2 == NULL) ||
1032: (len != session_id2_len) ||
1.108 djm 1033: (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 1034: fail++;
1035: }
1.183 markus 1036: if ((r = sshbuf_get_u8(b, &type)) != 0)
1037: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1038: if (type != SSH2_MSG_USERAUTH_REQUEST)
1.1 provos 1039: fail++;
1.183 markus 1040: if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1041: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.121 djm 1042: xasprintf(&userstyle, "%s%s%s", authctxt->user,
1043: authctxt->style ? ":" : "",
1044: authctxt->style ? authctxt->style : "");
1.159 djm 1045: if (strcmp(userstyle, cp) != 0) {
1046: logit("wrong user name passed to monitor: "
1047: "expected %s != %.100s", userstyle, cp);
1.1 provos 1048: fail++;
1049: }
1.124 djm 1050: free(userstyle);
1.159 djm 1051: free(cp);
1.183 markus 1052: if ((r = sshbuf_skip_string(b)) != 0 || /* service */
1053: (r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1054: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.178 djm 1055: if (strcmp("publickey", cp) != 0)
1056: fail++;
1057: free(cp);
1.183 markus 1058: if ((r = sshbuf_get_u8(b, &type)) != 0)
1059: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1060: if (type == 0)
1.178 djm 1061: fail++;
1.183 markus 1062: if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */
1063: (r = sshbuf_skip_string(b)) != 0) /* pkblob */
1064: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1065: if (sshbuf_len(b) != 0)
1.1 provos 1066: fail++;
1.183 markus 1067: sshbuf_free(b);
1.1 provos 1068: return (fail == 0);
1069: }
1070:
1071: static int
1.203 djm 1072: monitor_valid_hostbasedblob(const u_char *data, u_int datalen,
1073: const char *cuser, const char *chost)
1.1 provos 1074: {
1.183 markus 1075: struct sshbuf *b;
1076: const u_char *p;
1077: char *cp, *userstyle;
1078: size_t len;
1079: int r, fail = 0;
1080: u_char type;
1.1 provos 1081:
1.203 djm 1082: if ((b = sshbuf_from(data, datalen)) == NULL)
1.183 markus 1083: fatal("%s: sshbuf_new", __func__);
1.203 djm 1084: if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
1.183 markus 1085: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.3 markus 1086:
1.13 markus 1087: if ((session_id2 == NULL) ||
1088: (len != session_id2_len) ||
1.108 djm 1089: (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1.1 provos 1090: fail++;
1.13 markus 1091:
1.183 markus 1092: if ((r = sshbuf_get_u8(b, &type)) != 0)
1093: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1094: if (type != SSH2_MSG_USERAUTH_REQUEST)
1.1 provos 1095: fail++;
1.183 markus 1096: if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1097: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.121 djm 1098: xasprintf(&userstyle, "%s%s%s", authctxt->user,
1099: authctxt->style ? ":" : "",
1100: authctxt->style ? authctxt->style : "");
1.183 markus 1101: if (strcmp(userstyle, cp) != 0) {
1102: logit("wrong user name passed to monitor: "
1103: "expected %s != %.100s", userstyle, cp);
1.1 provos 1104: fail++;
1105: }
1.121 djm 1106: free(userstyle);
1.183 markus 1107: free(cp);
1108: if ((r = sshbuf_skip_string(b)) != 0 || /* service */
1109: (r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1110: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1111: if (strcmp(cp, "hostbased") != 0)
1.1 provos 1112: fail++;
1.183 markus 1113: free(cp);
1114: if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */
1115: (r = sshbuf_skip_string(b)) != 0) /* pkblob */
1116: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 1117:
1118: /* verify client host, strip trailing dot if necessary */
1.183 markus 1119: if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1120: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1121: if (((len = strlen(cp)) > 0) && cp[len - 1] == '.')
1122: cp[len - 1] = '\0';
1123: if (strcmp(cp, chost) != 0)
1.1 provos 1124: fail++;
1.183 markus 1125: free(cp);
1.1 provos 1126:
1127: /* verify client user */
1.183 markus 1128: if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1129: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1130: if (strcmp(cp, cuser) != 0)
1.1 provos 1131: fail++;
1.183 markus 1132: free(cp);
1.1 provos 1133:
1.183 markus 1134: if (sshbuf_len(b) != 0)
1.1 provos 1135: fail++;
1.183 markus 1136: sshbuf_free(b);
1.1 provos 1137: return (fail == 0);
1138: }
1139:
1140: int
1.191 djm 1141: mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 1142: {
1.168 markus 1143: struct sshkey *key;
1.203 djm 1144: const u_char *signature, *data, *blob;
1145: char *sigalg = NULL, *fp = NULL;
1.169 markus 1146: size_t signaturelen, datalen, bloblen;
1.203 djm 1147: int r, ret, req_presence = 0, valid_data = 0, encoded_ret;
1.202 djm 1148: struct sshkey_sig_details *sig_details = NULL;
1.1 provos 1149:
1.203 djm 1150: if ((r = sshbuf_get_string_direct(m, &blob, &bloblen)) != 0 ||
1151: (r = sshbuf_get_string_direct(m, &signature, &signaturelen)) != 0 ||
1152: (r = sshbuf_get_string_direct(m, &data, &datalen)) != 0 ||
1.176 djm 1153: (r = sshbuf_get_cstring(m, &sigalg, NULL)) != 0)
1.169 markus 1154: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 1155:
1156: if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1.8 mouring 1157: !monitor_allowed_key(blob, bloblen))
1.14 markus 1158: fatal("%s: bad key, not previously allowed", __func__);
1.1 provos 1159:
1.177 djm 1160: /* Empty signature algorithm means NULL. */
1161: if (*sigalg == '\0') {
1162: free(sigalg);
1163: sigalg = NULL;
1164: }
1165:
1.169 markus 1166: /* XXX use sshkey_froms here; need to change key_blob, etc. */
1167: if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
1168: fatal("%s: bad public key blob: %s", __func__, ssh_err(r));
1.1 provos 1169:
1170: switch (key_blobtype) {
1171: case MM_USERKEY:
1172: valid_data = monitor_valid_userblob(data, datalen);
1.172 djm 1173: auth_method = "publickey";
1.1 provos 1174: break;
1175: case MM_HOSTKEY:
1176: valid_data = monitor_valid_hostbasedblob(data, datalen,
1177: hostbased_cuser, hostbased_chost);
1.172 djm 1178: auth_method = "hostbased";
1.1 provos 1179: break;
1180: default:
1181: valid_data = 0;
1182: break;
1183: }
1184: if (!valid_data)
1.14 markus 1185: fatal("%s: bad signature data blob", __func__);
1.1 provos 1186:
1.203 djm 1187: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
1188: SSH_FP_DEFAULT)) == NULL)
1189: fatal("%s: sshkey_fingerprint failed", __func__);
1190:
1.169 markus 1191: ret = sshkey_verify(key, signature, signaturelen, data, datalen,
1.202 djm 1192: sigalg, ssh->compat, &sig_details);
1.201 djm 1193: debug3("%s: %s %p signature %s%s%s", __func__, auth_method, key,
1194: (ret == 0) ? "verified" : "unverified",
1195: (ret != 0) ? ": " : "", (ret != 0) ? ssh_err(ret) : "");
1.203 djm 1196:
1197: if (ret == 0 && key_blobtype == MM_USERKEY && sig_details != NULL) {
1198: req_presence = (options.pubkey_auth_options &
1.204 djm 1199: PUBKEYAUTH_TOUCH_REQUIRED) ||
1200: !key_opts->no_require_user_presence;
1.203 djm 1201: if (req_presence &&
1202: (sig_details->sk_flags & SSH_SK_USER_PRESENCE_REQD) == 0) {
1203: error("public key %s %s signature for %s%s from %.128s "
1.208 ! naddy 1204: "port %d rejected: user presence "
! 1205: "(authenticator touch) requirement not met ",
! 1206: sshkey_type(key), fp,
1.203 djm 1207: authctxt->valid ? "" : "invalid user ",
1208: authctxt->user, ssh_remote_ipaddr(ssh),
1209: ssh_remote_port(ssh));
1210: ret = SSH_ERR_SIGNATURE_INVALID;
1211: }
1212: }
1.172 djm 1213: auth2_record_key(authctxt, ret == 0, key);
1.136 djm 1214:
1.180 djm 1215: if (key_blobtype == MM_USERKEY)
1216: auth_activate_options(ssh, key_opts);
1.1 provos 1217: monitor_reset_key_state();
1.3 markus 1218:
1.169 markus 1219: sshbuf_reset(m);
1220:
1221: /* encode ret != 0 as positive integer, since we're sending u32 */
1222: encoded_ret = (ret != 0);
1.202 djm 1223: if ((r = sshbuf_put_u32(m, encoded_ret)) != 0 ||
1.205 djm 1224: (r = sshbuf_put_u8(m, sig_details != NULL)) != 0)
1.169 markus 1225: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.202 djm 1226: if (sig_details != NULL) {
1227: if ((r = sshbuf_put_u32(m, sig_details->sk_counter)) != 0 ||
1228: (r = sshbuf_put_u8(m, sig_details->sk_flags)) != 0)
1229: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1230: }
1231: sshkey_sig_details_free(sig_details);
1.59 avsm 1232: mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1.203 djm 1233:
1234: free(sigalg);
1235: free(fp);
1236: sshkey_free(key);
1.1 provos 1237:
1.169 markus 1238: return ret == 0;
1.1 provos 1239: }
1240:
1.2 markus 1241: static void
1.191 djm 1242: mm_record_login(struct ssh *ssh, Session *s, struct passwd *pw)
1.1 provos 1243: {
1244: socklen_t fromlen;
1245: struct sockaddr_storage from;
1246:
1247: /*
1248: * Get IP address of client. If the connection is not a socket, let
1249: * the address be 0.0.0.0.
1250: */
1251: memset(&from, 0, sizeof(from));
1.24 stevesk 1252: fromlen = sizeof(from);
1.191 djm 1253: if (ssh_packet_connection_is_on_socket(ssh)) {
1254: if (getpeername(ssh_packet_get_connection_in(ssh),
1.198 deraadt 1255: (struct sockaddr *)&from, &fromlen) == -1) {
1.1 provos 1256: debug("getpeername: %.100s", strerror(errno));
1.50 markus 1257: cleanup_exit(255);
1.1 provos 1258: }
1259: }
1260: /* Record that there was a login on that tty from the remote host. */
1261: record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1.158 djm 1262: session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns),
1.24 stevesk 1263: (struct sockaddr *)&from, fromlen);
1.1 provos 1264: }
1265:
1266: static void
1267: mm_session_close(Session *s)
1268: {
1.41 djm 1269: debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1.1 provos 1270: if (s->ttyfd != -1) {
1.86 stevesk 1271: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1.1 provos 1272: session_pty_cleanup2(s);
1273: }
1.96 djm 1274: session_unused(s->self);
1.1 provos 1275: }
1276:
1277: int
1.191 djm 1278: mm_answer_pty(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 1279: {
1.11 mouring 1280: extern struct monitor *pmonitor;
1.1 provos 1281: Session *s;
1.183 markus 1282: int r, res, fd0;
1.1 provos 1283:
1.14 markus 1284: debug3("%s entering", __func__);
1.1 provos 1285:
1.183 markus 1286: sshbuf_reset(m);
1.1 provos 1287: s = session_new();
1288: if (s == NULL)
1289: goto error;
1290: s->authctxt = authctxt;
1291: s->pw = authctxt->pw;
1.11 mouring 1292: s->pid = pmonitor->m_pid;
1.1 provos 1293: res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1294: if (res == 0)
1295: goto error;
1296: pty_setowner(authctxt->pw, s->tty);
1297:
1.183 markus 1298: if ((r = sshbuf_put_u32(m, 1)) != 0 ||
1299: (r = sshbuf_put_cstring(m, s->tty)) != 0)
1300: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 1301:
1302: /* We need to trick ttyslot */
1303: if (dup2(s->ttyfd, 0) == -1)
1.14 markus 1304: fatal("%s: dup2", __func__);
1.1 provos 1305:
1.191 djm 1306: mm_record_login(ssh, s, authctxt->pw);
1.1 provos 1307:
1308: /* Now we can close the file descriptor again */
1309: close(0);
1.61 dtucker 1310:
1311: /* send messages generated by record_login */
1.183 markus 1312: if ((r = sshbuf_put_stringb(m, loginmsg)) != 0)
1313: fatal("%s: put login message: %s", __func__, ssh_err(r));
1314: sshbuf_reset(loginmsg);
1.61 dtucker 1315:
1316: mm_request_send(sock, MONITOR_ANS_PTY, m);
1317:
1.92 djm 1318: if (mm_send_fd(sock, s->ptyfd) == -1 ||
1319: mm_send_fd(sock, s->ttyfd) == -1)
1320: fatal("%s: send fds failed", __func__);
1.1 provos 1321:
1322: /* make sure nothing uses fd 0 */
1.198 deraadt 1323: if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1.14 markus 1324: fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1.1 provos 1325: if (fd0 != 0)
1.14 markus 1326: error("%s: fd0 %d != 0", __func__, fd0);
1.1 provos 1327:
1328: /* slave is not needed */
1329: close(s->ttyfd);
1330: s->ttyfd = s->ptyfd;
1331: /* no need to dup() because nobody closes ptyfd */
1332: s->ptymaster = s->ptyfd;
1333:
1.86 stevesk 1334: debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1.1 provos 1335:
1336: return (0);
1337:
1338: error:
1339: if (s != NULL)
1340: mm_session_close(s);
1.183 markus 1341: if ((r = sshbuf_put_u32(m, 0)) != 0)
1342: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.59 avsm 1343: mm_request_send(sock, MONITOR_ANS_PTY, m);
1.1 provos 1344: return (0);
1345: }
1346:
1347: int
1.191 djm 1348: mm_answer_pty_cleanup(struct ssh *ssh, int sock, struct sshbuf *m)
1.1 provos 1349: {
1350: Session *s;
1351: char *tty;
1.183 markus 1352: int r;
1.1 provos 1353:
1.14 markus 1354: debug3("%s entering", __func__);
1.1 provos 1355:
1.183 markus 1356: if ((r = sshbuf_get_cstring(m, &tty, NULL)) != 0)
1357: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.1 provos 1358: if ((s = session_by_tty(tty)) != NULL)
1359: mm_session_close(s);
1.183 markus 1360: sshbuf_reset(m);
1.124 djm 1361: free(tty);
1.1 provos 1362: return (0);
1363: }
1364:
1365: int
1.191 djm 1366: mm_answer_term(struct ssh *ssh, int sock, struct sshbuf *req)
1.1 provos 1367: {
1.11 mouring 1368: extern struct monitor *pmonitor;
1.1 provos 1369: int res, status;
1370:
1.14 markus 1371: debug3("%s: tearing down sessions", __func__);
1.1 provos 1372:
1373: /* The child is terminating */
1.173 djm 1374: session_destroy_all(ssh, &mm_session_close);
1.1 provos 1375:
1.11 mouring 1376: while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1.9 markus 1377: if (errno != EINTR)
1378: exit(1);
1.1 provos 1379:
1380: res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1381:
1382: /* Terminate process */
1.57 deraadt 1383: exit(res);
1.170 markus 1384: }
1385:
1386: void
1.191 djm 1387: monitor_clear_keystate(struct ssh *ssh, struct monitor *pmonitor)
1.170 markus 1388: {
1389: ssh_clear_newkeys(ssh, MODE_IN);
1390: ssh_clear_newkeys(ssh, MODE_OUT);
1391: sshbuf_free(child_state);
1392: child_state = NULL;
1.1 provos 1393: }
1394:
1395: void
1.191 djm 1396: monitor_apply_keystate(struct ssh *ssh, struct monitor *pmonitor)
1.1 provos 1397: {
1.139 markus 1398: struct kex *kex;
1399: int r;
1400:
1401: debug3("%s: packet_set_state", __func__);
1402: if ((r = ssh_packet_set_state(ssh, child_state)) != 0)
1403: fatal("%s: packet_set_state: %s", __func__, ssh_err(r));
1404: sshbuf_free(child_state);
1405: child_state = NULL;
1406:
1.154 mmcc 1407: if ((kex = ssh->kex) != NULL) {
1.139 markus 1408: /* XXX set callbacks */
1.147 djm 1409: #ifdef WITH_OPENSSL
1.197 djm 1410: kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
1411: kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
1412: kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_server;
1413: kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_server;
1414: kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_server;
1.139 markus 1415: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1416: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1.197 djm 1417: kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
1.147 djm 1418: #endif
1.197 djm 1419: kex->kex[KEX_C25519_SHA256] = kex_gen_server;
1420: kex->kex[KEX_KEM_SNTRUP4591761X25519_SHA512] = kex_gen_server;
1.139 markus 1421: kex->load_host_public_key=&get_hostkey_public_by_type;
1422: kex->load_host_private_key=&get_hostkey_private_by_type;
1423: kex->host_key_index=&get_hostkey_index;
1424: kex->sign = sshd_hostkey_sign;
1425: }
1.1 provos 1426: }
1427:
1428: /* This function requries careful sanity checking */
1429:
1430: void
1.192 djm 1431: mm_get_keystate(struct ssh *ssh, struct monitor *pmonitor)
1.1 provos 1432: {
1.14 markus 1433: debug3("%s: Waiting for new keys", __func__);
1.1 provos 1434:
1.139 markus 1435: if ((child_state = sshbuf_new()) == NULL)
1436: fatal("%s: sshbuf_new failed", __func__);
1437: mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT,
1438: child_state);
1439: debug3("%s: GOT new keys", __func__);
1.1 provos 1440: }
1441:
1442:
1443: /* XXX */
1444:
1445: #define FD_CLOSEONEXEC(x) do { \
1.111 djm 1446: if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
1.1 provos 1447: fatal("fcntl(%d, F_SETFD)", x); \
1448: } while (0)
1449:
1.2 markus 1450: static void
1.114 djm 1451: monitor_openfds(struct monitor *mon, int do_logfds)
1.3 markus 1452: {
1.114 djm 1453: int pair[2];
1.171 markus 1454: #ifdef SO_ZEROIZE
1455: int on = 1;
1456: #endif
1.114 djm 1457:
1.1 provos 1458: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1.114 djm 1459: fatal("%s: socketpair: %s", __func__, strerror(errno));
1.171 markus 1460: #ifdef SO_ZEROIZE
1.198 deraadt 1461: if (setsockopt(pair[0], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
1.171 markus 1462: error("setsockopt SO_ZEROIZE(0): %.100s", strerror(errno));
1.198 deraadt 1463: if (setsockopt(pair[1], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
1.171 markus 1464: error("setsockopt SO_ZEROIZE(1): %.100s", strerror(errno));
1465: #endif
1.1 provos 1466: FD_CLOSEONEXEC(pair[0]);
1467: FD_CLOSEONEXEC(pair[1]);
1.114 djm 1468: mon->m_recvfd = pair[0];
1469: mon->m_sendfd = pair[1];
1470:
1471: if (do_logfds) {
1472: if (pipe(pair) == -1)
1473: fatal("%s: pipe: %s", __func__, strerror(errno));
1474: FD_CLOSEONEXEC(pair[0]);
1475: FD_CLOSEONEXEC(pair[1]);
1476: mon->m_log_recvfd = pair[0];
1477: mon->m_log_sendfd = pair[1];
1478: } else
1479: mon->m_log_recvfd = mon->m_log_sendfd = -1;
1.1 provos 1480: }
1481:
1482: #define MM_MEMSIZE 65536
1483:
1484: struct monitor *
1485: monitor_init(void)
1486: {
1487: struct monitor *mon;
1488:
1.75 djm 1489: mon = xcalloc(1, sizeof(*mon));
1.114 djm 1490: monitor_openfds(mon, 1);
1.1 provos 1491:
1492: return mon;
1493: }
1494:
1495: void
1496: monitor_reinit(struct monitor *mon)
1497: {
1.114 djm 1498: monitor_openfds(mon, 0);
1.1 provos 1499: }
1.46 markus 1500:
1501: #ifdef GSSAPI
1502: int
1.191 djm 1503: mm_answer_gss_setup_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
1.46 markus 1504: {
1.59 avsm 1505: gss_OID_desc goid;
1.46 markus 1506: OM_uint32 major;
1.183 markus 1507: size_t len;
1.184 djm 1508: u_char *p;
1.183 markus 1509: int r;
1.46 markus 1510:
1.164 djm 1511: if (!options.gss_authentication)
1512: fatal("%s: GSSAPI authentication not enabled", __func__);
1513:
1.184 djm 1514: if ((r = sshbuf_get_string(m, &p, &len)) != 0)
1.183 markus 1515: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.184 djm 1516: goid.elements = p;
1.59 avsm 1517: goid.length = len;
1.46 markus 1518:
1.59 avsm 1519: major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1.46 markus 1520:
1.124 djm 1521: free(goid.elements);
1.46 markus 1522:
1.183 markus 1523: sshbuf_reset(m);
1524: if ((r = sshbuf_put_u32(m, major)) != 0)
1525: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.46 markus 1526:
1.64 stevesk 1527: mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1.46 markus 1528:
1529: /* Now we have a context, enable the step */
1530: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1531:
1532: return (0);
1533: }
1534:
1535: int
1.191 djm 1536: mm_answer_gss_accept_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
1.46 markus 1537: {
1538: gss_buffer_desc in;
1539: gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1.64 stevesk 1540: OM_uint32 major, minor;
1.46 markus 1541: OM_uint32 flags = 0; /* GSI needs this */
1.183 markus 1542: int r;
1.46 markus 1543:
1.164 djm 1544: if (!options.gss_authentication)
1545: fatal("%s: GSSAPI authentication not enabled", __func__);
1546:
1.184 djm 1547: if ((r = ssh_gssapi_get_buffer_desc(m, &in)) != 0)
1.183 markus 1548: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.46 markus 1549: major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1.124 djm 1550: free(in.value);
1.46 markus 1551:
1.183 markus 1552: sshbuf_reset(m);
1553: if ((r = sshbuf_put_u32(m, major)) != 0 ||
1554: (r = sshbuf_put_string(m, out.value, out.length)) != 0 ||
1555: (r = sshbuf_put_u32(m, flags)) != 0)
1556: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.59 avsm 1557: mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1.46 markus 1558:
1559: gss_release_buffer(&minor, &out);
1560:
1.64 stevesk 1561: if (major == GSS_S_COMPLETE) {
1.46 markus 1562: monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1563: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.52 markus 1564: monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1.46 markus 1565: }
1566: return (0);
1567: }
1568:
1569: int
1.191 djm 1570: mm_answer_gss_checkmic(struct ssh *ssh, int sock, struct sshbuf *m)
1.52 markus 1571: {
1572: gss_buffer_desc gssbuf, mic;
1573: OM_uint32 ret;
1.184 djm 1574: int r;
1.54 djm 1575:
1.164 djm 1576: if (!options.gss_authentication)
1577: fatal("%s: GSSAPI authentication not enabled", __func__);
1578:
1.184 djm 1579: if ((r = ssh_gssapi_get_buffer_desc(m, &gssbuf)) != 0 ||
1580: (r = ssh_gssapi_get_buffer_desc(m, &mic)) != 0)
1.183 markus 1581: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.54 djm 1582:
1.52 markus 1583: ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1.54 djm 1584:
1.124 djm 1585: free(gssbuf.value);
1586: free(mic.value);
1.54 djm 1587:
1.183 markus 1588: sshbuf_reset(m);
1589: if ((r = sshbuf_put_u32(m, ret)) != 0)
1590: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.54 djm 1591:
1.59 avsm 1592: mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1.54 djm 1593:
1.52 markus 1594: if (!GSS_ERROR(ret))
1595: monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1.54 djm 1596:
1.52 markus 1597: return (0);
1598: }
1599:
1600: int
1.191 djm 1601: mm_answer_gss_userok(struct ssh *ssh, int sock, struct sshbuf *m)
1.46 markus 1602: {
1.184 djm 1603: int r, authenticated;
1.172 djm 1604: const char *displayname;
1.164 djm 1605:
1606: if (!options.gss_authentication)
1607: fatal("%s: GSSAPI authentication not enabled", __func__);
1.46 markus 1608:
1609: authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1610:
1.183 markus 1611: sshbuf_reset(m);
1612: if ((r = sshbuf_put_u32(m, authenticated)) != 0)
1613: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.46 markus 1614:
1615: debug3("%s: sending result %d", __func__, authenticated);
1.59 avsm 1616: mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1.46 markus 1617:
1.64 stevesk 1618: auth_method = "gssapi-with-mic";
1.172 djm 1619:
1620: if ((displayname = ssh_gssapi_displayname()) != NULL)
1621: auth2_record_info(authctxt, "%s", displayname);
1.46 markus 1622:
1623: /* Monitor loop will terminate if authenticated */
1624: return (authenticated);
1625: }
1626: #endif /* GSSAPI */
1.100 djm 1627:
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