Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 1 | /* |
Ben Lindstrom | 4469723 | 2001-07-04 03:32:30 +0000 | [diff] [blame] | 2 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * 1. Redistributions of source code must retain the above copyright |
| 8 | * notice, this list of conditions and the following disclaimer. |
| 9 | * 2. Redistributions in binary form must reproduce the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer in the |
| 11 | * documentation and/or other materials provided with the distribution. |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 12 | * |
| 13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 23 | */ |
| 24 | |
| 25 | #include "includes.h" |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 26 | |
| 27 | #include <openssl/crypto.h> |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 28 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 29 | #include "ssh2.h" |
| 30 | #include "xmalloc.h" |
| 31 | #include "buffer.h" |
| 32 | #include "bufaux.h" |
| 33 | #include "packet.h" |
| 34 | #include "compat.h" |
| 35 | #include "cipher.h" |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 36 | #include "kex.h" |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 37 | #include "key.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 38 | #include "log.h" |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 39 | #include "mac.h" |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 40 | #include "match.h" |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 41 | #include "dispatch.h" |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 42 | #include "monitor.h" |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 43 | |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 44 | #define KEX_COOKIE_LEN 16 |
| 45 | |
Damien Miller | b309203 | 2006-03-16 18:22:18 +1100 | [diff] [blame] | 46 | #if OPENSSL_VERSION_NUMBER >= 0x00907000L |
| 47 | # if defined(HAVE_EVP_SHA256) |
Damien Miller | af87af1 | 2006-03-15 13:02:28 +1100 | [diff] [blame] | 48 | # define evp_ssh_sha256 EVP_sha256 |
Damien Miller | b309203 | 2006-03-16 18:22:18 +1100 | [diff] [blame] | 49 | # else |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 50 | extern const EVP_MD *evp_ssh_sha256(void); |
Damien Miller | b309203 | 2006-03-16 18:22:18 +1100 | [diff] [blame] | 51 | # endif |
Tim Rice | 425a688 | 2006-03-15 20:17:05 -0800 | [diff] [blame] | 52 | #endif |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 53 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 54 | /* prototype */ |
| 55 | static void kex_kexinit_finish(Kex *); |
| 56 | static void kex_choose_conf(Kex *); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 57 | |
| 58 | /* put algorithm proposal into buffer */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 59 | static void |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 60 | kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX]) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 61 | { |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 62 | u_int i; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 63 | |
| 64 | buffer_clear(b); |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 65 | /* |
| 66 | * add a dummy cookie, the cookie will be overwritten by |
| 67 | * kex_send_kexinit(), each time a kexinit is set |
| 68 | */ |
| 69 | for (i = 0; i < KEX_COOKIE_LEN; i++) |
| 70 | buffer_put_char(b, 0); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 71 | for (i = 0; i < PROPOSAL_MAX; i++) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 72 | buffer_put_cstring(b, proposal[i]); |
| 73 | buffer_put_char(b, 0); /* first_kex_packet_follows */ |
| 74 | buffer_put_int(b, 0); /* uint32 reserved */ |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 75 | } |
| 76 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 77 | /* parse buffer and return algorithm proposal */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 78 | static char ** |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 79 | kex_buf2prop(Buffer *raw, int *first_kex_follows) |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 80 | { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 81 | Buffer b; |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 82 | int i; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 83 | char **proposal; |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 84 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 85 | proposal = xmalloc(PROPOSAL_MAX * sizeof(char *)); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 86 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 87 | buffer_init(&b); |
| 88 | buffer_append(&b, buffer_ptr(raw), buffer_len(raw)); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 89 | /* skip cookie */ |
| 90 | for (i = 0; i < KEX_COOKIE_LEN; i++) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 91 | buffer_get_char(&b); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 92 | /* extract kex init proposal strings */ |
| 93 | for (i = 0; i < PROPOSAL_MAX; i++) { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 94 | proposal[i] = buffer_get_string(&b,NULL); |
| 95 | debug2("kex_parse_kexinit: %s", proposal[i]); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 96 | } |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 97 | /* first kex follows / reserved */ |
| 98 | i = buffer_get_char(&b); |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 99 | if (first_kex_follows != NULL) |
| 100 | *first_kex_follows = i; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 101 | debug2("kex_parse_kexinit: first_kex_follows %d ", i); |
| 102 | i = buffer_get_int(&b); |
| 103 | debug2("kex_parse_kexinit: reserved %d ", i); |
| 104 | buffer_free(&b); |
| 105 | return proposal; |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 106 | } |
| 107 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 108 | static void |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 109 | kex_prop_free(char **proposal) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 110 | { |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 111 | u_int i; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 112 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 113 | for (i = 0; i < PROPOSAL_MAX; i++) |
| 114 | xfree(proposal[i]); |
| 115 | xfree(proposal); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 116 | } |
| 117 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 118 | static void |
Damien Miller | 630d6f4 | 2002-01-22 23:17:30 +1100 | [diff] [blame] | 119 | kex_protocol_error(int type, u_int32_t seq, void *ctxt) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 120 | { |
Damien Miller | 630d6f4 | 2002-01-22 23:17:30 +1100 | [diff] [blame] | 121 | error("Hm, kex protocol error: type %d seq %u", type, seq); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 122 | } |
| 123 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 124 | static void |
Damien Miller | bc27d4e | 2002-02-13 13:54:06 +1100 | [diff] [blame] | 125 | kex_reset_dispatch(void) |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 126 | { |
Damien Miller | 7d05339 | 2002-01-22 23:24:13 +1100 | [diff] [blame] | 127 | dispatch_range(SSH2_MSG_TRANSPORT_MIN, |
| 128 | SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error); |
Damien Miller | bc27d4e | 2002-02-13 13:54:06 +1100 | [diff] [blame] | 129 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 130 | } |
| 131 | |
| 132 | void |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 133 | kex_finish(Kex *kex) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 134 | { |
Damien Miller | bc27d4e | 2002-02-13 13:54:06 +1100 | [diff] [blame] | 135 | kex_reset_dispatch(); |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 136 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 137 | packet_start(SSH2_MSG_NEWKEYS); |
| 138 | packet_send(); |
| 139 | /* packet_write_wait(); */ |
| 140 | debug("SSH2_MSG_NEWKEYS sent"); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 141 | |
Ben Lindstrom | 064496f | 2002-12-23 02:04:22 +0000 | [diff] [blame] | 142 | debug("expecting SSH2_MSG_NEWKEYS"); |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 143 | packet_read_expect(SSH2_MSG_NEWKEYS); |
Ben Lindstrom | 1451908 | 2002-02-26 17:58:29 +0000 | [diff] [blame] | 144 | packet_check_eom(); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 145 | debug("SSH2_MSG_NEWKEYS received"); |
Ben Lindstrom | 5ba23b3 | 2001-04-05 02:05:21 +0000 | [diff] [blame] | 146 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 147 | kex->done = 1; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 148 | buffer_clear(&kex->peer); |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 149 | /* buffer_clear(&kex->my); */ |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 150 | kex->flags &= ~KEX_INIT_SENT; |
Ben Lindstrom | 5ba23b3 | 2001-04-05 02:05:21 +0000 | [diff] [blame] | 151 | xfree(kex->name); |
| 152 | kex->name = NULL; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 153 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 154 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 155 | void |
| 156 | kex_send_kexinit(Kex *kex) |
| 157 | { |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 158 | u_int32_t rnd = 0; |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 159 | u_char *cookie; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 160 | u_int i; |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 161 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 162 | if (kex == NULL) { |
| 163 | error("kex_send_kexinit: no kex, cannot rekey"); |
| 164 | return; |
| 165 | } |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 166 | if (kex->flags & KEX_INIT_SENT) { |
| 167 | debug("KEX_INIT_SENT"); |
| 168 | return; |
| 169 | } |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 170 | kex->done = 0; |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 171 | |
| 172 | /* generate a random cookie */ |
| 173 | if (buffer_len(&kex->my) < KEX_COOKIE_LEN) |
| 174 | fatal("kex_send_kexinit: kex proposal too short"); |
| 175 | cookie = buffer_ptr(&kex->my); |
| 176 | for (i = 0; i < KEX_COOKIE_LEN; i++) { |
| 177 | if (i % 4 == 0) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 178 | rnd = arc4random(); |
| 179 | cookie[i] = rnd; |
| 180 | rnd >>= 8; |
Ben Lindstrom | 5997172 | 2002-03-27 17:42:57 +0000 | [diff] [blame] | 181 | } |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 182 | packet_start(SSH2_MSG_KEXINIT); |
| 183 | packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my)); |
| 184 | packet_send(); |
| 185 | debug("SSH2_MSG_KEXINIT sent"); |
| 186 | kex->flags |= KEX_INIT_SENT; |
| 187 | } |
| 188 | |
| 189 | void |
Damien Miller | 630d6f4 | 2002-01-22 23:17:30 +1100 | [diff] [blame] | 190 | kex_input_kexinit(int type, u_int32_t seq, void *ctxt) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 191 | { |
| 192 | char *ptr; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 193 | u_int i, dlen; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 194 | Kex *kex = (Kex *)ctxt; |
| 195 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 196 | debug("SSH2_MSG_KEXINIT received"); |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 197 | if (kex == NULL) |
| 198 | fatal("kex_input_kexinit: no kex, cannot rekey"); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 199 | |
| 200 | ptr = packet_get_raw(&dlen); |
| 201 | buffer_append(&kex->peer, ptr, dlen); |
| 202 | |
Ben Lindstrom | 8e312f3 | 2001-04-04 23:50:21 +0000 | [diff] [blame] | 203 | /* discard packet */ |
| 204 | for (i = 0; i < KEX_COOKIE_LEN; i++) |
| 205 | packet_get_char(); |
| 206 | for (i = 0; i < PROPOSAL_MAX; i++) |
| 207 | xfree(packet_get_string(NULL)); |
Ben Lindstrom | c5a7f4f | 2002-06-25 23:19:13 +0000 | [diff] [blame] | 208 | (void) packet_get_char(); |
| 209 | (void) packet_get_int(); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 210 | packet_check_eom(); |
Ben Lindstrom | 8e312f3 | 2001-04-04 23:50:21 +0000 | [diff] [blame] | 211 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 212 | kex_kexinit_finish(kex); |
| 213 | } |
| 214 | |
| 215 | Kex * |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 216 | kex_setup(char *proposal[PROPOSAL_MAX]) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 217 | { |
| 218 | Kex *kex; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 219 | |
| 220 | kex = xmalloc(sizeof(*kex)); |
| 221 | memset(kex, 0, sizeof(*kex)); |
| 222 | buffer_init(&kex->peer); |
| 223 | buffer_init(&kex->my); |
| 224 | kex_prop2buf(&kex->my, proposal); |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 225 | kex->done = 0; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 226 | |
| 227 | kex_send_kexinit(kex); /* we start */ |
Damien Miller | bc27d4e | 2002-02-13 13:54:06 +1100 | [diff] [blame] | 228 | kex_reset_dispatch(); |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 229 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 230 | return kex; |
| 231 | } |
| 232 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 233 | static void |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 234 | kex_kexinit_finish(Kex *kex) |
| 235 | { |
| 236 | if (!(kex->flags & KEX_INIT_SENT)) |
| 237 | kex_send_kexinit(kex); |
| 238 | |
| 239 | kex_choose_conf(kex); |
| 240 | |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 241 | if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX && |
| 242 | kex->kex[kex->kex_type] != NULL) { |
| 243 | (kex->kex[kex->kex_type])(kex); |
| 244 | } else { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 245 | fatal("Unsupported key exchange %d", kex->kex_type); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 246 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 247 | } |
| 248 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 249 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 250 | choose_enc(Enc *enc, char *client, char *server) |
| 251 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 252 | char *name = match_list(client, server, NULL); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 253 | if (name == NULL) |
| 254 | fatal("no matching cipher found: client %s server %s", client, server); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 255 | if ((enc->cipher = cipher_by_name(name)) == NULL) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 256 | fatal("matching cipher is not supported: %s", name); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 257 | enc->name = name; |
| 258 | enc->enabled = 0; |
| 259 | enc->iv = NULL; |
| 260 | enc->key = NULL; |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 261 | enc->key_len = cipher_keylen(enc->cipher); |
| 262 | enc->block_size = cipher_blocksize(enc->cipher); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 263 | } |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 264 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 265 | choose_mac(Mac *mac, char *client, char *server) |
| 266 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 267 | char *name = match_list(client, server, NULL); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 268 | if (name == NULL) |
| 269 | fatal("no matching mac found: client %s server %s", client, server); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 270 | if (mac_init(mac, name) < 0) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 271 | fatal("unsupported mac %s", name); |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 272 | /* truncate the key */ |
| 273 | if (datafellows & SSH_BUG_HMAC) |
| 274 | mac->key_len = 16; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 275 | mac->name = name; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 276 | mac->key = NULL; |
| 277 | mac->enabled = 0; |
| 278 | } |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 279 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 280 | choose_comp(Comp *comp, char *client, char *server) |
| 281 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 282 | char *name = match_list(client, server, NULL); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 283 | if (name == NULL) |
| 284 | fatal("no matching comp found: client %s server %s", client, server); |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 285 | if (strcmp(name, "zlib@openssh.com") == 0) { |
| 286 | comp->type = COMP_DELAYED; |
| 287 | } else if (strcmp(name, "zlib") == 0) { |
| 288 | comp->type = COMP_ZLIB; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 289 | } else if (strcmp(name, "none") == 0) { |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 290 | comp->type = COMP_NONE; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 291 | } else { |
| 292 | fatal("unsupported comp %s", name); |
| 293 | } |
| 294 | comp->name = name; |
| 295 | } |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 296 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 297 | choose_kex(Kex *k, char *client, char *server) |
| 298 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 299 | k->name = match_list(client, server, NULL); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 300 | if (k->name == NULL) |
| 301 | fatal("no kex alg"); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 302 | if (strcmp(k->name, KEX_DH1) == 0) { |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 303 | k->kex_type = KEX_DH_GRP1_SHA1; |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 304 | k->evp_md = EVP_sha1(); |
Damien Miller | f675fc4 | 2004-06-15 10:30:09 +1000 | [diff] [blame] | 305 | } else if (strcmp(k->name, KEX_DH14) == 0) { |
| 306 | k->kex_type = KEX_DH_GRP14_SHA1; |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 307 | k->evp_md = EVP_sha1(); |
| 308 | } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) { |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 309 | k->kex_type = KEX_DH_GEX_SHA1; |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 310 | k->evp_md = EVP_sha1(); |
Damien Miller | b309203 | 2006-03-16 18:22:18 +1100 | [diff] [blame] | 311 | #if OPENSSL_VERSION_NUMBER >= 0x00907000L |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 312 | } else if (strcmp(k->name, KEX_DHGEX_SHA256) == 0) { |
| 313 | k->kex_type = KEX_DH_GEX_SHA256; |
| 314 | k->evp_md = evp_ssh_sha256(); |
Damien Miller | b309203 | 2006-03-16 18:22:18 +1100 | [diff] [blame] | 315 | #endif |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 316 | } else |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 317 | fatal("bad kex alg %s", k->name); |
| 318 | } |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 319 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 320 | static void |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 321 | choose_hostkeyalg(Kex *k, char *client, char *server) |
| 322 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 323 | char *hostkeyalg = match_list(client, server, NULL); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 324 | if (hostkeyalg == NULL) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 325 | fatal("no hostkey alg"); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 326 | k->hostkey_type = key_type_from_name(hostkeyalg); |
| 327 | if (k->hostkey_type == KEY_UNSPEC) |
| 328 | fatal("bad hostkey alg '%s'", hostkeyalg); |
Ben Lindstrom | 48bd7c1 | 2001-01-09 00:35:42 +0000 | [diff] [blame] | 329 | xfree(hostkeyalg); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 330 | } |
| 331 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 332 | static int |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 333 | proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX]) |
| 334 | { |
| 335 | static int check[] = { |
| 336 | PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1 |
| 337 | }; |
| 338 | int *idx; |
| 339 | char *p; |
| 340 | |
| 341 | for (idx = &check[0]; *idx != -1; idx++) { |
| 342 | if ((p = strchr(my[*idx], ',')) != NULL) |
| 343 | *p = '\0'; |
| 344 | if ((p = strchr(peer[*idx], ',')) != NULL) |
| 345 | *p = '\0'; |
| 346 | if (strcmp(my[*idx], peer[*idx]) != 0) { |
| 347 | debug2("proposal mismatch: my %s peer %s", |
| 348 | my[*idx], peer[*idx]); |
| 349 | return (0); |
| 350 | } |
| 351 | } |
| 352 | debug2("proposals match"); |
| 353 | return (1); |
| 354 | } |
| 355 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 356 | static void |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 357 | kex_choose_conf(Kex *kex) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 358 | { |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 359 | Newkeys *newkeys; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 360 | char **my, **peer; |
| 361 | char **cprop, **sprop; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 362 | int nenc, nmac, ncomp; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 363 | u_int mode, ctos, need; |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 364 | int first_kex_follows, type; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 365 | |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 366 | my = kex_buf2prop(&kex->my, NULL); |
| 367 | peer = kex_buf2prop(&kex->peer, &first_kex_follows); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 368 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 369 | if (kex->server) { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 370 | cprop=peer; |
| 371 | sprop=my; |
| 372 | } else { |
| 373 | cprop=my; |
| 374 | sprop=peer; |
| 375 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 376 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 377 | /* Algorithm Negotiation */ |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 378 | for (mode = 0; mode < MODE_MAX; mode++) { |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 379 | newkeys = xmalloc(sizeof(*newkeys)); |
| 380 | memset(newkeys, 0, sizeof(*newkeys)); |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 381 | kex->newkeys[mode] = newkeys; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 382 | ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 383 | nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC; |
| 384 | nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC; |
| 385 | ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 386 | choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]); |
| 387 | choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]); |
| 388 | choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 389 | debug("kex: %s %s %s %s", |
| 390 | ctos ? "client->server" : "server->client", |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 391 | newkeys->enc.name, |
| 392 | newkeys->mac.name, |
| 393 | newkeys->comp.name); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 394 | } |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 395 | choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]); |
| 396 | choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS], |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 397 | sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 398 | need = 0; |
| 399 | for (mode = 0; mode < MODE_MAX; mode++) { |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 400 | newkeys = kex->newkeys[mode]; |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 401 | if (need < newkeys->enc.key_len) |
| 402 | need = newkeys->enc.key_len; |
| 403 | if (need < newkeys->enc.block_size) |
| 404 | need = newkeys->enc.block_size; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 405 | if (need < newkeys->mac.key_len) |
| 406 | need = newkeys->mac.key_len; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 407 | } |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 408 | /* XXX need runden? */ |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 409 | kex->we_need = need; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 410 | |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 411 | /* ignore the next message if the proposals do not match */ |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 412 | if (first_kex_follows && !proposals_match(my, peer) && |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame] | 413 | !(datafellows & SSH_BUG_FIRSTKEX)) { |
Damien Miller | babb47a | 2003-02-24 11:53:32 +1100 | [diff] [blame] | 414 | type = packet_read(); |
| 415 | debug2("skipping next packet (type %u)", type); |
| 416 | } |
| 417 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 418 | kex_prop_free(my); |
| 419 | kex_prop_free(peer); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 420 | } |
| 421 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 422 | static u_char * |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 423 | derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen, |
| 424 | BIGNUM *shared_secret) |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 425 | { |
| 426 | Buffer b; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 427 | EVP_MD_CTX md; |
| 428 | char c = id; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 429 | u_int have; |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 430 | int mdsz; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 431 | u_char *digest; |
Damien Miller | 46d38de | 2005-07-17 17:02:09 +1000 | [diff] [blame] | 432 | |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 433 | if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0) |
| 434 | fatal("bad kex md size %d", mdsz); |
Damien Miller | c91e556 | 2006-03-26 13:58:55 +1100 | [diff] [blame] | 435 | digest = xmalloc(roundup(need, mdsz)); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 436 | |
| 437 | buffer_init(&b); |
| 438 | buffer_put_bignum2(&b, shared_secret); |
| 439 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 440 | /* K1 = HASH(K || H || "A" || session_id) */ |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 441 | EVP_DigestInit(&md, kex->evp_md); |
Ben Lindstrom | 8c96392 | 2001-04-30 23:06:57 +0000 | [diff] [blame] | 442 | if (!(datafellows & SSH_BUG_DERIVEKEY)) |
| 443 | EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 444 | EVP_DigestUpdate(&md, hash, hashlen); |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 445 | EVP_DigestUpdate(&md, &c, 1); |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 446 | EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 447 | EVP_DigestFinal(&md, digest, NULL); |
| 448 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 449 | /* |
| 450 | * expand key: |
| 451 | * Kn = HASH(K || H || K1 || K2 || ... || Kn-1) |
| 452 | * Key = K1 || K2 || ... || Kn |
| 453 | */ |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 454 | for (have = mdsz; need > have; have += mdsz) { |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 455 | EVP_DigestInit(&md, kex->evp_md); |
Ben Lindstrom | 8c96392 | 2001-04-30 23:06:57 +0000 | [diff] [blame] | 456 | if (!(datafellows & SSH_BUG_DERIVEKEY)) |
| 457 | EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 458 | EVP_DigestUpdate(&md, hash, hashlen); |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 459 | EVP_DigestUpdate(&md, digest, have); |
| 460 | EVP_DigestFinal(&md, digest + have, NULL); |
| 461 | } |
| 462 | buffer_free(&b); |
| 463 | #ifdef DEBUG_KEX |
| 464 | fprintf(stderr, "key '%c'== ", c); |
| 465 | dump_digest("key", digest, need); |
| 466 | #endif |
| 467 | return digest; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 468 | } |
| 469 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 470 | Newkeys *current_keys[MODE_MAX]; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 471 | |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 472 | #define NKEYS 6 |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 473 | void |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 474 | kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret) |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 475 | { |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 476 | u_char *keys[NKEYS]; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 477 | u_int i, mode, ctos; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 478 | |
Damien Miller | 19bb3a5 | 2005-11-05 15:19:35 +1100 | [diff] [blame] | 479 | for (i = 0; i < NKEYS; i++) { |
| 480 | keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen, |
| 481 | shared_secret); |
| 482 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 483 | |
Ben Lindstrom | 064496f | 2002-12-23 02:04:22 +0000 | [diff] [blame] | 484 | debug2("kex_derive_keys"); |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 485 | for (mode = 0; mode < MODE_MAX; mode++) { |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 486 | current_keys[mode] = kex->newkeys[mode]; |
| 487 | kex->newkeys[mode] = NULL; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 488 | ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN); |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 489 | current_keys[mode]->enc.iv = keys[ctos ? 0 : 1]; |
| 490 | current_keys[mode]->enc.key = keys[ctos ? 2 : 3]; |
| 491 | current_keys[mode]->mac.key = keys[ctos ? 4 : 5]; |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 492 | } |
Damien Miller | a664e87 | 2000-04-16 11:52:47 +1000 | [diff] [blame] | 493 | } |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 494 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 495 | Newkeys * |
| 496 | kex_get_newkeys(int mode) |
| 497 | { |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 498 | Newkeys *ret; |
| 499 | |
| 500 | ret = current_keys[mode]; |
| 501 | current_keys[mode] = NULL; |
| 502 | return ret; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 503 | } |
| 504 | |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 505 | void |
| 506 | derive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus, |
| 507 | u_int8_t cookie[8], u_int8_t id[16]) |
| 508 | { |
| 509 | const EVP_MD *evp_md = EVP_md5(); |
| 510 | EVP_MD_CTX md; |
| 511 | u_int8_t nbuf[2048], obuf[EVP_MAX_MD_SIZE]; |
| 512 | int len; |
| 513 | |
| 514 | EVP_DigestInit(&md, evp_md); |
| 515 | |
| 516 | len = BN_num_bytes(host_modulus); |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 517 | if (len < (512 / 8) || (u_int)len > sizeof(nbuf)) |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 518 | fatal("%s: bad host modulus (len %d)", __func__, len); |
| 519 | BN_bn2bin(host_modulus, nbuf); |
| 520 | EVP_DigestUpdate(&md, nbuf, len); |
| 521 | |
| 522 | len = BN_num_bytes(server_modulus); |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 523 | if (len < (512 / 8) || (u_int)len > sizeof(nbuf)) |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 524 | fatal("%s: bad server modulus (len %d)", __func__, len); |
| 525 | BN_bn2bin(server_modulus, nbuf); |
| 526 | EVP_DigestUpdate(&md, nbuf, len); |
| 527 | |
| 528 | EVP_DigestUpdate(&md, cookie, 8); |
| 529 | |
Darren Tucker | b42714e | 2004-05-13 16:31:48 +1000 | [diff] [blame] | 530 | EVP_DigestFinal(&md, obuf, NULL); |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 531 | memcpy(id, obuf, 16); |
| 532 | |
| 533 | memset(nbuf, 0, sizeof(nbuf)); |
| 534 | memset(obuf, 0, sizeof(obuf)); |
| 535 | memset(&md, 0, sizeof(md)); |
| 536 | } |
| 537 | |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 538 | #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) |
| 539 | void |
| 540 | dump_digest(char *msg, u_char *digest, int len) |
| 541 | { |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 542 | u_int i; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 543 | |
| 544 | fprintf(stderr, "%s\n", msg); |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 545 | for (i = 0; i< len; i++) { |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 546 | fprintf(stderr, "%02x", digest[i]); |
| 547 | if (i%32 == 31) |
| 548 | fprintf(stderr, "\n"); |
| 549 | else if (i%8 == 7) |
| 550 | fprintf(stderr, " "); |
| 551 | } |
| 552 | fprintf(stderr, "\n"); |
| 553 | } |
| 554 | #endif |