version 1.32.2.4, 2001/03/21 18:52:55 |
version 1.33, 2000/06/20 01:39:43 |
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/* |
/* |
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* |
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* packet.c |
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* |
* Author: Tatu Ylonen <ylo@cs.hut.fi> |
* Author: Tatu Ylonen <ylo@cs.hut.fi> |
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* |
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
* All rights reserved |
* All rights reserved |
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* |
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* Created: Sat Mar 18 02:40:40 1995 ylo |
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* |
* This file contains code implementing the packet protocol and communication |
* This file contains code implementing the packet protocol and communication |
* with the other side. This same code is used both on client and server side. |
* with the other side. This same code is used both on client and server side. |
* |
* |
* As far as I am concerned, the code I have written for this software |
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* can be used freely for any purpose. Any derived versions of this |
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* software must be clearly marked as such, and if the derived work is |
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* incompatible with the protocol description in the RFC file, it must be |
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* called by a name other than "ssh" or "Secure Shell". |
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* |
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* |
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* SSH2 packet format added by Markus Friedl. |
* SSH2 packet format added by Markus Friedl. |
* Copyright (c) 2000 Markus Friedl. All rights reserved. |
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* |
* |
* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
*/ |
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#include "includes.h" |
#include "includes.h" |
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#include "buffer.h" |
#include "buffer.h" |
#include "packet.h" |
#include "packet.h" |
#include "bufaux.h" |
#include "bufaux.h" |
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#include "ssh.h" |
#include "crc32.h" |
#include "crc32.h" |
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#include "cipher.h" |
#include "getput.h" |
#include "getput.h" |
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#include "compress.h" |
#include "compress.h" |
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#include "channels.h" |
#include "channels.h" |
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#include "compat.h" |
#include "compat.h" |
#include "ssh1.h" |
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#include "ssh2.h" |
#include "ssh2.h" |
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#include "cipher.h" |
#include <openssl/bn.h> |
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#include <openssl/dh.h> |
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#include <openssl/hmac.h> |
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#include "buffer.h" |
#include "kex.h" |
#include "kex.h" |
#include "mac.h" |
#include "hmac.h" |
#include "log.h" |
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#include "canohost.h" |
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#ifdef PACKET_DEBUG |
#ifdef PACKET_DEBUG |
#define DBG(x) x |
#define DBG(x) x |
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static int cipher_type = SSH_CIPHER_NONE; |
static int cipher_type = SSH_CIPHER_NONE; |
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/* Protocol flags for the remote side. */ |
/* Protocol flags for the remote side. */ |
static u_int remote_protocol_flags = 0; |
static unsigned int remote_protocol_flags = 0; |
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/* Encryption context for receiving data. This is only used for decryption. */ |
/* Encryption context for receiving data. This is only used for decryption. */ |
static CipherContext receive_context; |
static CipherContext receive_context; |
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void |
void |
packet_set_connection(int fd_in, int fd_out) |
packet_set_connection(int fd_in, int fd_out) |
{ |
{ |
Cipher *none = cipher_by_name("none"); |
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if (none == NULL) |
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fatal("packet_set_connection: cannot load cipher 'none'"); |
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connection_in = fd_in; |
connection_in = fd_in; |
connection_out = fd_out; |
connection_out = fd_out; |
cipher_type = SSH_CIPHER_NONE; |
cipher_type = SSH_CIPHER_NONE; |
cipher_init(&send_context, none, (u_char *) "", 0, NULL, 0); |
cipher_set_key(&send_context, SSH_CIPHER_NONE, (unsigned char *) "", 0); |
cipher_init(&receive_context, none, (u_char *) "", 0, NULL, 0); |
cipher_set_key(&receive_context, SSH_CIPHER_NONE, (unsigned char *) "", 0); |
if (!initialized) { |
if (!initialized) { |
initialized = 1; |
initialized = 1; |
buffer_init(&input); |
buffer_init(&input); |
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/* Sets remote side protocol flags. */ |
/* Sets remote side protocol flags. */ |
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void |
void |
packet_set_protocol_flags(u_int protocol_flags) |
packet_set_protocol_flags(unsigned int protocol_flags) |
{ |
{ |
remote_protocol_flags = protocol_flags; |
remote_protocol_flags = protocol_flags; |
channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0); |
channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0); |
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/* Returns the remote protocol flags set earlier by the above function. */ |
/* Returns the remote protocol flags set earlier by the above function. */ |
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u_int |
unsigned int |
packet_get_protocol_flags() |
packet_get_protocol_flags() |
{ |
{ |
return remote_protocol_flags; |
return remote_protocol_flags; |
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void |
void |
packet_encrypt(CipherContext * cc, void *dest, void *src, |
packet_encrypt(CipherContext * cc, void *dest, void *src, |
u_int bytes) |
unsigned int bytes) |
{ |
{ |
cipher_encrypt(cc, dest, src, bytes); |
cipher_encrypt(cc, dest, src, bytes); |
} |
} |
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*/ |
*/ |
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void |
void |
packet_decrypt(CipherContext *context, void *dest, void *src, u_int bytes) |
packet_decrypt(CipherContext * cc, void *dest, void *src, |
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unsigned int bytes) |
{ |
{ |
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int i; |
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if ((bytes % 8) != 0) |
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fatal("packet_decrypt: bad ciphertext length %d", bytes); |
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/* |
/* |
* Cryptographic attack detector for ssh - Modifications for packet.c |
* Cryptographic attack detector for ssh - Modifications for packet.c |
* (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com) |
* (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com) |
*/ |
*/ |
if (!compat20 && |
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context->cipher->number != SSH_CIPHER_NONE && |
if (cc->type == SSH_CIPHER_NONE || compat20) { |
detect_attack(src, bytes, NULL) == DEATTACK_DETECTED) |
i = DEATTACK_OK; |
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} else { |
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i = detect_attack(src, bytes, NULL); |
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} |
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if (i == DEATTACK_DETECTED) |
packet_disconnect("crc32 compensation attack: network attack detected"); |
packet_disconnect("crc32 compensation attack: network attack detected"); |
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cipher_decrypt(context, dest, src, bytes); |
cipher_decrypt(cc, dest, src, bytes); |
} |
} |
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/* |
/* |
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*/ |
*/ |
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void |
void |
packet_set_encryption_key(const u_char *key, u_int keylen, |
packet_set_encryption_key(const unsigned char *key, unsigned int keylen, |
int number) |
int cipher) |
{ |
{ |
Cipher *cipher = cipher_by_number(number); |
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if (cipher == NULL) |
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fatal("packet_set_encryption_key: unknown cipher number %d", number); |
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if (keylen < 20) |
if (keylen < 20) |
fatal("packet_set_encryption_key: keylen too small: %d", keylen); |
fatal("keylen too small: %d", keylen); |
cipher_init(&receive_context, cipher, key, keylen, NULL, 0); |
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cipher_init(&send_context, cipher, key, keylen, NULL, 0); |
/* All other ciphers use the same key in both directions for now. */ |
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cipher_set_key(&receive_context, cipher, key, keylen); |
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cipher_set_key(&send_context, cipher, key, keylen); |
} |
} |
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/* Starts constructing a packet to send. */ |
/* Starts constructing a packet to send. */ |
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void |
void |
packet_start(int type) |
packet_start(int type) |
{ |
{ |
DBG(debug("packet_start[%d]", type)); |
DBG(debug("packet_start[%d]",type)); |
if (use_ssh2_packet_format) |
if (use_ssh2_packet_format) |
packet_start2(type); |
packet_start2(type); |
else |
else |
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/* Appends an integer to the packet data. */ |
/* Appends an integer to the packet data. */ |
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void |
void |
packet_put_int(u_int value) |
packet_put_int(unsigned int value) |
{ |
{ |
buffer_put_int(&outgoing_packet, value); |
buffer_put_int(&outgoing_packet, value); |
} |
} |
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/* Appends a string to packet data. */ |
/* Appends a string to packet data. */ |
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void |
void |
packet_put_string(const char *buf, u_int len) |
packet_put_string(const char *buf, unsigned int len) |
{ |
{ |
buffer_put_string(&outgoing_packet, buf, len); |
buffer_put_string(&outgoing_packet, buf, len); |
} |
} |
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} |
} |
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void |
void |
packet_put_raw(const char *buf, u_int len) |
packet_put_raw(const char *buf, unsigned int len) |
{ |
{ |
buffer_append(&outgoing_packet, buf, len); |
buffer_append(&outgoing_packet, buf, len); |
} |
} |
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*/ |
*/ |
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void |
void |
packet_send1(void) |
packet_send1() |
{ |
{ |
char buf[8], *cp; |
char buf[8], *cp; |
int i, padding, len; |
int i, padding, len; |
u_int checksum; |
unsigned int checksum; |
u_int32_t rand = 0; |
u_int32_t rand = 0; |
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/* |
/* |
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buffer_consume(&outgoing_packet, 8 - padding); |
buffer_consume(&outgoing_packet, 8 - padding); |
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/* Add check bytes. */ |
/* Add check bytes. */ |
checksum = ssh_crc32((u_char *) buffer_ptr(&outgoing_packet), |
checksum = crc32((unsigned char *) buffer_ptr(&outgoing_packet), |
buffer_len(&outgoing_packet)); |
buffer_len(&outgoing_packet)); |
PUT_32BIT(buf, checksum); |
PUT_32BIT(buf, checksum); |
buffer_append(&outgoing_packet, buf, 4); |
buffer_append(&outgoing_packet, buf, 4); |
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* Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) |
* Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) |
*/ |
*/ |
void |
void |
packet_send2(void) |
packet_send2() |
{ |
{ |
static u_int32_t seqnr = 0; |
unsigned char *macbuf = NULL; |
u_char *macbuf = NULL; |
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char *cp; |
char *cp; |
u_int packet_length = 0; |
unsigned int packet_length = 0; |
u_int i, padlen, len; |
unsigned int i, padlen, len; |
u_int32_t rand = 0; |
u_int32_t rand = 0; |
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static unsigned int seqnr = 0; |
int type; |
int type; |
Enc *enc = NULL; |
Enc *enc = NULL; |
Mac *mac = NULL; |
Mac *mac = NULL; |
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mac = &kex->mac[MODE_OUT]; |
mac = &kex->mac[MODE_OUT]; |
comp = &kex->comp[MODE_OUT]; |
comp = &kex->comp[MODE_OUT]; |
} |
} |
block_size = enc ? enc->cipher->block_size : 8; |
block_size = enc ? enc->block_size : 8; |
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cp = buffer_ptr(&outgoing_packet); |
cp = buffer_ptr(&outgoing_packet); |
type = cp[5] & 0xff; |
type = cp[5] & 0xff; |
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if (padlen < 4) |
if (padlen < 4) |
padlen += block_size; |
padlen += block_size; |
buffer_append_space(&outgoing_packet, &cp, padlen); |
buffer_append_space(&outgoing_packet, &cp, padlen); |
if (enc && enc->cipher->number != SSH_CIPHER_NONE) { |
if (enc && enc->type != SSH_CIPHER_NONE) { |
/* random padding */ |
/* random padding */ |
for (i = 0; i < padlen; i++) { |
for (i = 0; i < padlen; i++) { |
if (i % 4 == 0) |
if (i % 4 == 0) |
rand = arc4random(); |
rand = arc4random(); |
cp[i] = rand & 0xff; |
cp[i] = rand & 0xff; |
rand >>= 8; |
rand <<= 8; |
} |
} |
} else { |
} else { |
/* clear padding */ |
/* clear padding */ |
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/* compute MAC over seqnr and packet(length fields, payload, padding) */ |
/* compute MAC over seqnr and packet(length fields, payload, padding) */ |
if (mac && mac->enabled) { |
if (mac && mac->enabled) { |
macbuf = mac_compute(mac, seqnr, |
macbuf = hmac( mac->md, seqnr, |
(u_char *) buffer_ptr(&outgoing_packet), |
(unsigned char *) buffer_ptr(&outgoing_packet), |
buffer_len(&outgoing_packet)); |
buffer_len(&outgoing_packet), |
DBG(debug("done calc MAC out #%d", seqnr)); |
mac->key, mac->key_len |
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); |
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DBG(debug("done calc HMAC out #%d", seqnr)); |
} |
} |
/* encrypt packet and append to output buffer. */ |
/* encrypt packet and append to output buffer. */ |
buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); |
buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); |
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fatal("packet_send2: no KEX"); |
fatal("packet_send2: no KEX"); |
if (mac->md != NULL) |
if (mac->md != NULL) |
mac->enabled = 1; |
mac->enabled = 1; |
DBG(debug("cipher_init send_context")); |
DBG(debug("cipher_set_key_iv send_context")); |
cipher_init(&send_context, enc->cipher, |
cipher_set_key_iv(&send_context, enc->type, |
enc->key, enc->cipher->key_len, |
enc->key, enc->key_len, |
enc->iv, enc->cipher->block_size); |
enc->iv, enc->iv_len); |
clear_enc_keys(enc, kex->we_need); |
clear_enc_keys(enc, kex->we_need); |
if (comp->type != 0 && comp->enabled == 0) { |
if (comp->type != 0 && comp->enabled == 0) { |
comp->enabled = 1; |
comp->enabled = 1; |
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packet_read(int *payload_len_ptr) |
packet_read(int *payload_len_ptr) |
{ |
{ |
int type, len; |
int type, len; |
fd_set *setp; |
fd_set set; |
char buf[8192]; |
char buf[8192]; |
DBG(debug("packet_read()")); |
DBG(debug("packet_read()")); |
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setp = (fd_set *)xmalloc(howmany(connection_in+1, NFDBITS) * |
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sizeof(fd_mask)); |
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/* Since we are blocking, ensure that all written packets have been sent. */ |
/* Since we are blocking, ensure that all written packets have been sent. */ |
packet_write_wait(); |
packet_write_wait(); |
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|| type == SSH_CMSG_EXIT_CONFIRMATION)) |
|| type == SSH_CMSG_EXIT_CONFIRMATION)) |
packet_integrity_check(*payload_len_ptr, 0, type); |
packet_integrity_check(*payload_len_ptr, 0, type); |
/* If we got a packet, return it. */ |
/* If we got a packet, return it. */ |
if (type != SSH_MSG_NONE) { |
if (type != SSH_MSG_NONE) |
xfree(setp); |
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return type; |
return type; |
} |
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/* |
/* |
* Otherwise, wait for some data to arrive, add it to the |
* Otherwise, wait for some data to arrive, add it to the |
* buffer, and try again. |
* buffer, and try again. |
*/ |
*/ |
memset(setp, 0, howmany(connection_in + 1, NFDBITS) * |
FD_ZERO(&set); |
sizeof(fd_mask)); |
FD_SET(connection_in, &set); |
FD_SET(connection_in, setp); |
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/* Wait for some data to arrive. */ |
/* Wait for some data to arrive. */ |
while (select(connection_in + 1, setp, NULL, NULL, NULL) == -1 && |
select(connection_in + 1, &set, NULL, NULL, NULL); |
(errno == EAGAIN || errno == EINTR)) |
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; |
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/* Read data from the socket. */ |
/* Read data from the socket. */ |
len = read(connection_in, buf, sizeof(buf)); |
len = read(connection_in, buf, sizeof(buf)); |
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int |
int |
packet_read_poll1(int *payload_len_ptr) |
packet_read_poll1(int *payload_len_ptr) |
{ |
{ |
u_int len, padded_len; |
unsigned int len, padded_len; |
u_char *ucp; |
unsigned char *ucp; |
char buf[8], *cp; |
char buf[8], *cp; |
u_int checksum, stored_checksum; |
unsigned int checksum, stored_checksum; |
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/* Check if input size is less than minimum packet size. */ |
/* Check if input size is less than minimum packet size. */ |
if (buffer_len(&input) < 4 + 8) |
if (buffer_len(&input) < 4 + 8) |
return SSH_MSG_NONE; |
return SSH_MSG_NONE; |
/* Get length of incoming packet. */ |
/* Get length of incoming packet. */ |
ucp = (u_char *) buffer_ptr(&input); |
ucp = (unsigned char *) buffer_ptr(&input); |
len = GET_32BIT(ucp); |
len = GET_32BIT(ucp); |
if (len < 1 + 2 + 2 || len > 256 * 1024) |
if (len < 1 + 2 + 2 || len > 256 * 1024) |
packet_disconnect("Bad packet length %d.", len); |
packet_disconnect("Bad packet length %d.", len); |
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#endif |
#endif |
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/* Compute packet checksum. */ |
/* Compute packet checksum. */ |
checksum = ssh_crc32((u_char *) buffer_ptr(&incoming_packet), |
checksum = crc32((unsigned char *) buffer_ptr(&incoming_packet), |
buffer_len(&incoming_packet) - 4); |
buffer_len(&incoming_packet) - 4); |
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/* Skip padding. */ |
/* Skip padding. */ |
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packet_disconnect("packet_read_poll: len %d != buffer_len %d.", |
packet_disconnect("packet_read_poll: len %d != buffer_len %d.", |
len, buffer_len(&incoming_packet)); |
len, buffer_len(&incoming_packet)); |
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ucp = (u_char *) buffer_ptr(&incoming_packet) + len - 4; |
ucp = (unsigned char *) buffer_ptr(&incoming_packet) + len - 4; |
stored_checksum = GET_32BIT(ucp); |
stored_checksum = GET_32BIT(ucp); |
if (checksum != stored_checksum) |
if (checksum != stored_checksum) |
packet_disconnect("Corrupted check bytes on input."); |
packet_disconnect("Corrupted check bytes on input."); |
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*payload_len_ptr = buffer_len(&incoming_packet); |
*payload_len_ptr = buffer_len(&incoming_packet); |
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/* Return type. */ |
/* Return type. */ |
return (u_char) buf[0]; |
return (unsigned char) buf[0]; |
} |
} |
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int |
int |
packet_read_poll2(int *payload_len_ptr) |
packet_read_poll2(int *payload_len_ptr) |
{ |
{ |
static u_int32_t seqnr = 0; |
unsigned int padlen, need; |
static u_int packet_length = 0; |
unsigned char buf[8], *macbuf; |
u_int padlen, need; |
unsigned char *ucp; |
u_char buf[8], *macbuf; |
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u_char *ucp; |
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char *cp; |
char *cp; |
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static unsigned int packet_length = 0; |
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static unsigned int seqnr = 0; |
int type; |
int type; |
int maclen, block_size; |
int maclen, block_size; |
Enc *enc = NULL; |
Enc *enc = NULL; |
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comp = &kex->comp[MODE_IN]; |
comp = &kex->comp[MODE_IN]; |
} |
} |
maclen = mac && mac->enabled ? mac->mac_len : 0; |
maclen = mac && mac->enabled ? mac->mac_len : 0; |
block_size = enc ? enc->cipher->block_size : 8; |
block_size = enc ? enc->block_size : 8; |
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if (packet_length == 0) { |
if (packet_length == 0) { |
/* |
/* |
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buffer_append_space(&incoming_packet, &cp, block_size); |
buffer_append_space(&incoming_packet, &cp, block_size); |
packet_decrypt(&receive_context, cp, buffer_ptr(&input), |
packet_decrypt(&receive_context, cp, buffer_ptr(&input), |
block_size); |
block_size); |
ucp = (u_char *) buffer_ptr(&incoming_packet); |
ucp = (unsigned char *) buffer_ptr(&incoming_packet); |
packet_length = GET_32BIT(ucp); |
packet_length = GET_32BIT(ucp); |
if (packet_length < 1 + 4 || packet_length > 256 * 1024) { |
if (packet_length < 1 + 4 || packet_length > 256 * 1024) { |
buffer_dump(&incoming_packet); |
buffer_dump(&incoming_packet); |
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* increment sequence number for incoming packet |
* increment sequence number for incoming packet |
*/ |
*/ |
if (mac && mac->enabled) { |
if (mac && mac->enabled) { |
macbuf = mac_compute(mac, seqnr, |
macbuf = hmac( mac->md, seqnr, |
(u_char *) buffer_ptr(&incoming_packet), |
(unsigned char *) buffer_ptr(&incoming_packet), |
buffer_len(&incoming_packet)); |
buffer_len(&incoming_packet), |
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mac->key, mac->key_len |
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); |
if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) |
if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) |
packet_disconnect("Corrupted MAC on input."); |
packet_disconnect("Corrupted HMAC on input."); |
DBG(debug("MAC #%d ok", seqnr)); |
DBG(debug("HMAC #%d ok", seqnr)); |
buffer_consume(&input, mac->mac_len); |
buffer_consume(&input, mac->mac_len); |
} |
} |
if (++seqnr == 0) |
if (++seqnr == 0) |
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packet_length = 0; |
packet_length = 0; |
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/* extract packet type */ |
/* extract packet type */ |
type = (u_char)buf[0]; |
type = (unsigned char)buf[0]; |
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if (type == SSH2_MSG_NEWKEYS) { |
if (type == SSH2_MSG_NEWKEYS) { |
if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) |
if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) |
fatal("packet_read_poll2: no KEX"); |
fatal("packet_read_poll2: no KEX"); |
if (mac->md != NULL) |
if (mac->md != NULL) |
mac->enabled = 1; |
mac->enabled = 1; |
DBG(debug("cipher_init receive_context")); |
DBG(debug("cipher_set_key_iv receive_context")); |
cipher_init(&receive_context, enc->cipher, |
cipher_set_key_iv(&receive_context, enc->type, |
enc->key, enc->cipher->key_len, |
enc->key, enc->key_len, |
enc->iv, enc->cipher->block_size); |
enc->iv, enc->iv_len); |
clear_enc_keys(enc, kex->we_need); |
clear_enc_keys(enc, kex->we_need); |
if (comp->type != 0 && comp->enabled == 0) { |
if (comp->type != 0 && comp->enabled == 0) { |
comp->enabled = 1; |
comp->enabled = 1; |
|
|
} |
} |
|
|
#ifdef PACKET_DEBUG |
#ifdef PACKET_DEBUG |
fprintf(stderr, "read/plain[%d]:\r\n", type); |
fprintf(stderr, "read/plain[%d]:\r\n",type); |
buffer_dump(&incoming_packet); |
buffer_dump(&incoming_packet); |
#endif |
#endif |
return (u_char)type; |
return (unsigned char)type; |
} |
} |
|
|
int |
int |
|
|
case SSH2_MSG_DISCONNECT: |
case SSH2_MSG_DISCONNECT: |
reason = packet_get_int(); |
reason = packet_get_int(); |
msg = packet_get_string(NULL); |
msg = packet_get_string(NULL); |
log("Received disconnect from %s: %d: %.400s", get_remote_ipaddr(), |
log("Received disconnect: %d: %.900s", reason, msg); |
reason, msg); |
|
xfree(msg); |
xfree(msg); |
fatal_cleanup(); |
fatal_cleanup(); |
break; |
break; |
default: |
default: |
return type; |
return type; |
break; |
break; |
} |
} |
} else { |
} else { |
switch(type) { |
switch(type) { |
case SSH_MSG_IGNORE: |
case SSH_MSG_IGNORE: |
|
|
break; |
break; |
case SSH_MSG_DISCONNECT: |
case SSH_MSG_DISCONNECT: |
msg = packet_get_string(NULL); |
msg = packet_get_string(NULL); |
log("Received disconnect from %s: %.400s", get_remote_ipaddr(), |
log("Received disconnect: %.900s", msg); |
msg); |
|
fatal_cleanup(); |
fatal_cleanup(); |
xfree(msg); |
xfree(msg); |
break; |
break; |
|
|
DBG(debug("received packet type %d", type)); |
DBG(debug("received packet type %d", type)); |
return type; |
return type; |
break; |
break; |
} |
} |
} |
} |
} |
} |
} |
} |
|
|
*/ |
*/ |
|
|
void |
void |
packet_process_incoming(const char *buf, u_int len) |
packet_process_incoming(const char *buf, unsigned int len) |
{ |
{ |
buffer_append(&input, buf, len); |
buffer_append(&input, buf, len); |
} |
} |
|
|
/* Returns a character from the packet. */ |
/* Returns a character from the packet. */ |
|
|
u_int |
unsigned int |
packet_get_char() |
packet_get_char() |
{ |
{ |
char ch; |
char ch; |
buffer_get(&incoming_packet, &ch, 1); |
buffer_get(&incoming_packet, &ch, 1); |
return (u_char) ch; |
return (unsigned char) ch; |
} |
} |
|
|
/* Returns an integer from the packet data. */ |
/* Returns an integer from the packet data. */ |
|
|
u_int |
unsigned int |
packet_get_int() |
packet_get_int() |
{ |
{ |
return buffer_get_int(&incoming_packet); |
return buffer_get_int(&incoming_packet); |
|
|
*/ |
*/ |
|
|
char * |
char * |
packet_get_string(u_int *length_ptr) |
packet_get_string(unsigned int *length_ptr) |
{ |
{ |
return buffer_get_string(&incoming_packet, length_ptr); |
return buffer_get_string(&incoming_packet, length_ptr); |
} |
} |
|
|
char buf[1024]; |
char buf[1024]; |
va_list args; |
va_list args; |
|
|
if (compat20 && (datafellows & SSH_BUG_DEBUG)) |
|
return; |
|
|
|
va_start(args, fmt); |
va_start(args, fmt); |
vsnprintf(buf, sizeof(buf), fmt, args); |
vsnprintf(buf, sizeof(buf), fmt, args); |
va_end(args); |
va_end(args); |
|
|
void |
void |
packet_write_wait() |
packet_write_wait() |
{ |
{ |
fd_set *setp; |
|
|
|
setp = (fd_set *)xmalloc(howmany(connection_out + 1, NFDBITS) * |
|
sizeof(fd_mask)); |
|
packet_write_poll(); |
packet_write_poll(); |
while (packet_have_data_to_write()) { |
while (packet_have_data_to_write()) { |
memset(setp, 0, howmany(connection_out + 1, NFDBITS) * |
fd_set set; |
sizeof(fd_mask)); |
FD_ZERO(&set); |
FD_SET(connection_out, setp); |
FD_SET(connection_out, &set); |
while (select(connection_out + 1, NULL, setp, NULL, NULL) == -1 && |
select(connection_out + 1, NULL, &set, NULL, NULL); |
(errno == EAGAIN || errno == EINTR)) |
|
; |
|
packet_write_poll(); |
packet_write_poll(); |
} |
} |
xfree(setp); |
|
} |
} |
|
|
/* Returns true if there is buffered data to write to the connection. */ |
/* Returns true if there is buffered data to write to the connection. */ |
|
|
/* Informs that the current session is interactive. Sets IP flags for that. */ |
/* Informs that the current session is interactive. Sets IP flags for that. */ |
|
|
void |
void |
packet_set_interactive(int interactive) |
packet_set_interactive(int interactive, int keepalives) |
{ |
{ |
static int called = 0; |
|
int lowdelay = IPTOS_LOWDELAY; |
|
int throughput = IPTOS_THROUGHPUT; |
|
int on = 1; |
int on = 1; |
|
|
if (called) |
|
return; |
|
called = 1; |
|
|
|
/* Record that we are in interactive mode. */ |
/* Record that we are in interactive mode. */ |
interactive_mode = interactive; |
interactive_mode = interactive; |
|
|
/* Only set socket options if using a socket. */ |
/* Only set socket options if using a socket. */ |
if (!packet_connection_is_on_socket()) |
if (!packet_connection_is_on_socket()) |
return; |
return; |
|
if (keepalives) { |
|
/* Set keepalives if requested. */ |
|
if (setsockopt(connection_in, SOL_SOCKET, SO_KEEPALIVE, (void *) &on, |
|
sizeof(on)) < 0) |
|
error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
|
} |
/* |
/* |
* IPTOS_LOWDELAY and IPTOS_THROUGHPUT are IPv4 only |
* IPTOS_LOWDELAY, TCP_NODELAY and IPTOS_THROUGHPUT are IPv4 only |
*/ |
*/ |
|
if (!packet_connection_is_ipv4()) |
|
return; |
if (interactive) { |
if (interactive) { |
/* |
/* |
* Set IP options for an interactive connection. Use |
* Set IP options for an interactive connection. Use |
* IPTOS_LOWDELAY and TCP_NODELAY. |
* IPTOS_LOWDELAY and TCP_NODELAY. |
*/ |
*/ |
if (packet_connection_is_ipv4()) { |
int lowdelay = IPTOS_LOWDELAY; |
if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, |
if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &lowdelay, |
(void *) &lowdelay, sizeof(lowdelay)) < 0) |
sizeof(lowdelay)) < 0) |
error("setsockopt IPTOS_LOWDELAY: %.100s", |
error("setsockopt IPTOS_LOWDELAY: %.100s", strerror(errno)); |
strerror(errno)); |
|
} |
|
if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on, |
if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on, |
sizeof(on)) < 0) |
sizeof(on)) < 0) |
error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); |
error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); |
} else if (packet_connection_is_ipv4()) { |
} else { |
/* |
/* |
* Set IP options for a non-interactive connection. Use |
* Set IP options for a non-interactive connection. Use |
* IPTOS_THROUGHPUT. |
* IPTOS_THROUGHPUT. |
*/ |
*/ |
|
int throughput = IPTOS_THROUGHPUT; |
if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput, |
if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput, |
sizeof(throughput)) < 0) |
sizeof(throughput)) < 0) |
error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno)); |
error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno)); |
|
|
log("packet_set_maxsize: setting to %d", s); |
log("packet_set_maxsize: setting to %d", s); |
max_packet_size = s; |
max_packet_size = s; |
return s; |
return s; |
} |
|
|
|
/* |
|
* 9.2. Ignored Data Message |
|
* |
|
* byte SSH_MSG_IGNORE |
|
* string data |
|
* |
|
* All implementations MUST understand (and ignore) this message at any |
|
* time (after receiving the protocol version). No implementation is |
|
* required to send them. This message can be used as an additional |
|
* protection measure against advanced traffic analysis techniques. |
|
*/ |
|
/* size of current + ignore message should be n*sumlen bytes (w/o mac) */ |
|
void |
|
packet_inject_ignore(int sumlen) |
|
{ |
|
int blocksize, padlen, have, need, nb, mini, nbytes; |
|
Enc *enc = NULL; |
|
|
|
if (use_ssh2_packet_format == 0) |
|
return; |
|
|
|
have = buffer_len(&outgoing_packet); |
|
debug2("packet_inject_ignore: current %d", have); |
|
if (kex != NULL) |
|
enc = &kex->enc[MODE_OUT]; |
|
blocksize = enc ? enc->cipher->block_size : 8; |
|
padlen = blocksize - (have % blocksize); |
|
if (padlen < 4) |
|
padlen += blocksize; |
|
have += padlen; |
|
have /= blocksize; /* # of blocks for current message */ |
|
|
|
nb = roundup(sumlen, blocksize) / blocksize; /* blocks for both */ |
|
mini = roundup(5+1+4+4, blocksize) / blocksize; /* minsize ignore msg */ |
|
need = nb - (have % nb); /* blocks for ignore */ |
|
if (need <= mini) |
|
need += nb; |
|
nbytes = (need - mini) * blocksize; /* size of ignore payload */ |
|
debug2("packet_inject_ignore: block %d have %d nb %d mini %d need %d", |
|
blocksize, have, nb, mini, need); |
|
|
|
/* enqueue current message and append a ignore message */ |
|
packet_send(); |
|
packet_send_ignore(nbytes); |
|
} |
|
|
|
void |
|
packet_send_ignore(int nbytes) |
|
{ |
|
u_int32_t rand = 0; |
|
int i; |
|
|
|
packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE); |
|
packet_put_int(nbytes); |
|
for(i = 0; i < nbytes; i++) { |
|
if (i % 4 == 0) |
|
rand = arc4random(); |
|
packet_put_char(rand & 0xff); |
|
rand >>= 8; |
|
} |
|
} |
} |