| File: | src/usr.bin/ssh/ssh/../kex.c |
| Warning: | line 785, column 8 Although the value stored to 'r' is used in the enclosing expression, the value is never actually read from 'r' |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
| 1 | /* $OpenBSD: kex.c,v 1.185 2024/01/08 00:34:33 djm Exp $ */ |
| 2 | /* |
| 3 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 15 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 16 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 17 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 18 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 19 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 20 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 21 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 23 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | #include <sys/types.h> |
| 28 | #include <errno(*__errno()).h> |
| 29 | #include <signal.h> |
| 30 | #include <stdio.h> |
| 31 | #include <stdlib.h> |
| 32 | #include <string.h> |
| 33 | #include <unistd.h> |
| 34 | #include <poll.h> |
| 35 | |
| 36 | #ifdef WITH_OPENSSL1 |
| 37 | #include <openssl/crypto.h> |
| 38 | #endif |
| 39 | |
| 40 | #include "ssh.h" |
| 41 | #include "ssh2.h" |
| 42 | #include "atomicio.h" |
| 43 | #include "version.h" |
| 44 | #include "packet.h" |
| 45 | #include "compat.h" |
| 46 | #include "cipher.h" |
| 47 | #include "sshkey.h" |
| 48 | #include "kex.h" |
| 49 | #include "log.h" |
| 50 | #include "mac.h" |
| 51 | #include "match.h" |
| 52 | #include "misc.h" |
| 53 | #include "dispatch.h" |
| 54 | #include "monitor.h" |
| 55 | #include "myproposal.h" |
| 56 | |
| 57 | #include "ssherr.h" |
| 58 | #include "sshbuf.h" |
| 59 | #include "digest.h" |
| 60 | #include "xmalloc.h" |
| 61 | |
| 62 | /* prototype */ |
| 63 | static int kex_choose_conf(struct ssh *, uint32_t seq); |
| 64 | static int kex_input_newkeys(int, u_int32_t, struct ssh *); |
| 65 | |
| 66 | static const char * const proposal_names[PROPOSAL_MAX] = { |
| 67 | "KEX algorithms", |
| 68 | "host key algorithms", |
| 69 | "ciphers ctos", |
| 70 | "ciphers stoc", |
| 71 | "MACs ctos", |
| 72 | "MACs stoc", |
| 73 | "compression ctos", |
| 74 | "compression stoc", |
| 75 | "languages ctos", |
| 76 | "languages stoc", |
| 77 | }; |
| 78 | |
| 79 | struct kexalg { |
| 80 | char *name; |
| 81 | u_int type; |
| 82 | int ec_nid; |
| 83 | int hash_alg; |
| 84 | }; |
| 85 | static const struct kexalg kexalgs[] = { |
| 86 | #ifdef WITH_OPENSSL1 |
| 87 | { KEX_DH1"diffie-hellman-group1-sha1", KEX_DH_GRP1_SHA1, 0, SSH_DIGEST_SHA11 }, |
| 88 | { KEX_DH14_SHA1"diffie-hellman-group14-sha1", KEX_DH_GRP14_SHA1, 0, SSH_DIGEST_SHA11 }, |
| 89 | { KEX_DH14_SHA256"diffie-hellman-group14-sha256", KEX_DH_GRP14_SHA256, 0, SSH_DIGEST_SHA2562 }, |
| 90 | { KEX_DH16_SHA512"diffie-hellman-group16-sha512", KEX_DH_GRP16_SHA512, 0, SSH_DIGEST_SHA5124 }, |
| 91 | { KEX_DH18_SHA512"diffie-hellman-group18-sha512", KEX_DH_GRP18_SHA512, 0, SSH_DIGEST_SHA5124 }, |
| 92 | { KEX_DHGEX_SHA1"diffie-hellman-group-exchange-sha1", KEX_DH_GEX_SHA1, 0, SSH_DIGEST_SHA11 }, |
| 93 | { KEX_DHGEX_SHA256"diffie-hellman-group-exchange-sha256", KEX_DH_GEX_SHA256, 0, SSH_DIGEST_SHA2562 }, |
| 94 | { KEX_ECDH_SHA2_NISTP256"ecdh-sha2-nistp256", KEX_ECDH_SHA2, |
| 95 | NID_X9_62_prime256v1415, SSH_DIGEST_SHA2562 }, |
| 96 | { KEX_ECDH_SHA2_NISTP384"ecdh-sha2-nistp384", KEX_ECDH_SHA2, NID_secp384r1715, |
| 97 | SSH_DIGEST_SHA3843 }, |
| 98 | { KEX_ECDH_SHA2_NISTP521"ecdh-sha2-nistp521", KEX_ECDH_SHA2, NID_secp521r1716, |
| 99 | SSH_DIGEST_SHA5124 }, |
| 100 | #endif |
| 101 | { KEX_CURVE25519_SHA256"curve25519-sha256", KEX_C25519_SHA256, 0, SSH_DIGEST_SHA2562 }, |
| 102 | { KEX_CURVE25519_SHA256_OLD"curve25519-sha256@libssh.org", KEX_C25519_SHA256, 0, SSH_DIGEST_SHA2562 }, |
| 103 | { KEX_SNTRUP761X25519_SHA512"sntrup761x25519-sha512@openssh.com", KEX_KEM_SNTRUP761X25519_SHA512, 0, |
| 104 | SSH_DIGEST_SHA5124 }, |
| 105 | { NULL((void *)0), 0, -1, -1}, |
| 106 | }; |
| 107 | |
| 108 | char * |
| 109 | kex_alg_list(char sep) |
| 110 | { |
| 111 | char *ret = NULL((void *)0), *tmp; |
| 112 | size_t nlen, rlen = 0; |
| 113 | const struct kexalg *k; |
| 114 | |
| 115 | for (k = kexalgs; k->name != NULL((void *)0); k++) { |
| 116 | if (ret != NULL((void *)0)) |
| 117 | ret[rlen++] = sep; |
| 118 | nlen = strlen(k->name); |
| 119 | if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL((void *)0)) { |
| 120 | free(ret); |
| 121 | return NULL((void *)0); |
| 122 | } |
| 123 | ret = tmp; |
| 124 | memcpy(ret + rlen, k->name, nlen + 1); |
| 125 | rlen += nlen; |
| 126 | } |
| 127 | return ret; |
| 128 | } |
| 129 | |
| 130 | static const struct kexalg * |
| 131 | kex_alg_by_name(const char *name) |
| 132 | { |
| 133 | const struct kexalg *k; |
| 134 | |
| 135 | for (k = kexalgs; k->name != NULL((void *)0); k++) { |
| 136 | if (strcmp(k->name, name) == 0) |
| 137 | return k; |
| 138 | } |
| 139 | return NULL((void *)0); |
| 140 | } |
| 141 | |
| 142 | /* Validate KEX method name list */ |
| 143 | int |
| 144 | kex_names_valid(const char *names) |
| 145 | { |
| 146 | char *s, *cp, *p; |
| 147 | |
| 148 | if (names == NULL((void *)0) || strcmp(names, "") == 0) |
| 149 | return 0; |
| 150 | if ((s = cp = strdup(names)) == NULL((void *)0)) |
| 151 | return 0; |
| 152 | for ((p = strsep(&cp, ",")); p && *p != '\0'; |
| 153 | (p = strsep(&cp, ","))) { |
| 154 | if (kex_alg_by_name(p) == NULL((void *)0)) { |
| 155 | error("Unsupported KEX algorithm \"%.100s\"", p)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 155, 0, SYSLOG_LEVEL_ERROR, ((void *)0), "Unsupported KEX algorithm \"%.100s\"" , p); |
| 156 | free(s); |
| 157 | return 0; |
| 158 | } |
| 159 | } |
| 160 | debug3("kex names ok: [%s]", names)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 160, 0, SYSLOG_LEVEL_DEBUG3, ((void *)0), "kex names ok: [%s]", names ); |
| 161 | free(s); |
| 162 | return 1; |
| 163 | } |
| 164 | |
| 165 | /* returns non-zero if proposal contains any algorithm from algs */ |
| 166 | static int |
| 167 | has_any_alg(const char *proposal, const char *algs) |
| 168 | { |
| 169 | char *cp; |
| 170 | |
| 171 | if ((cp = match_list(proposal, algs, NULL((void *)0))) == NULL((void *)0)) |
| 172 | return 0; |
| 173 | free(cp); |
| 174 | return 1; |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * Concatenate algorithm names, avoiding duplicates in the process. |
| 179 | * Caller must free returned string. |
| 180 | */ |
| 181 | char * |
| 182 | kex_names_cat(const char *a, const char *b) |
| 183 | { |
| 184 | char *ret = NULL((void *)0), *tmp = NULL((void *)0), *cp, *p; |
| 185 | size_t len; |
| 186 | |
| 187 | if (a == NULL((void *)0) || *a == '\0') |
| 188 | return strdup(b); |
| 189 | if (b == NULL((void *)0) || *b == '\0') |
| 190 | return strdup(a); |
| 191 | if (strlen(b) > 1024*1024) |
| 192 | return NULL((void *)0); |
| 193 | len = strlen(a) + strlen(b) + 2; |
| 194 | if ((tmp = cp = strdup(b)) == NULL((void *)0) || |
| 195 | (ret = calloc(1, len)) == NULL((void *)0)) { |
| 196 | free(tmp); |
| 197 | return NULL((void *)0); |
| 198 | } |
| 199 | strlcpy(ret, a, len); |
| 200 | for ((p = strsep(&cp, ",")); p && *p != '\0'; (p = strsep(&cp, ","))) { |
| 201 | if (has_any_alg(ret, p)) |
| 202 | continue; /* Algorithm already present */ |
| 203 | if (strlcat(ret, ",", len) >= len || |
| 204 | strlcat(ret, p, len) >= len) { |
| 205 | free(tmp); |
| 206 | free(ret); |
| 207 | return NULL((void *)0); /* Shouldn't happen */ |
| 208 | } |
| 209 | } |
| 210 | free(tmp); |
| 211 | return ret; |
| 212 | } |
| 213 | |
| 214 | /* |
| 215 | * Assemble a list of algorithms from a default list and a string from a |
| 216 | * configuration file. The user-provided string may begin with '+' to |
| 217 | * indicate that it should be appended to the default, '-' that the |
| 218 | * specified names should be removed, or '^' that they should be placed |
| 219 | * at the head. |
| 220 | */ |
| 221 | int |
| 222 | kex_assemble_names(char **listp, const char *def, const char *all) |
| 223 | { |
| 224 | char *cp, *tmp, *patterns; |
| 225 | char *list = NULL((void *)0), *ret = NULL((void *)0), *matching = NULL((void *)0), *opatterns = NULL((void *)0); |
| 226 | int r = SSH_ERR_INTERNAL_ERROR-1; |
| 227 | |
| 228 | if (listp == NULL((void *)0) || def == NULL((void *)0) || all == NULL((void *)0)) |
| 229 | return SSH_ERR_INVALID_ARGUMENT-10; |
| 230 | |
| 231 | if (*listp == NULL((void *)0) || **listp == '\0') { |
| 232 | if ((*listp = strdup(def)) == NULL((void *)0)) |
| 233 | return SSH_ERR_ALLOC_FAIL-2; |
| 234 | return 0; |
| 235 | } |
| 236 | |
| 237 | list = *listp; |
| 238 | *listp = NULL((void *)0); |
| 239 | if (*list == '+') { |
| 240 | /* Append names to default list */ |
| 241 | if ((tmp = kex_names_cat(def, list + 1)) == NULL((void *)0)) { |
| 242 | r = SSH_ERR_ALLOC_FAIL-2; |
| 243 | goto fail; |
| 244 | } |
| 245 | free(list); |
| 246 | list = tmp; |
| 247 | } else if (*list == '-') { |
| 248 | /* Remove names from default list */ |
| 249 | if ((*listp = match_filter_denylist(def, list + 1)) == NULL((void *)0)) { |
| 250 | r = SSH_ERR_ALLOC_FAIL-2; |
| 251 | goto fail; |
| 252 | } |
| 253 | free(list); |
| 254 | /* filtering has already been done */ |
| 255 | return 0; |
| 256 | } else if (*list == '^') { |
| 257 | /* Place names at head of default list */ |
| 258 | if ((tmp = kex_names_cat(list + 1, def)) == NULL((void *)0)) { |
| 259 | r = SSH_ERR_ALLOC_FAIL-2; |
| 260 | goto fail; |
| 261 | } |
| 262 | free(list); |
| 263 | list = tmp; |
| 264 | } else { |
| 265 | /* Explicit list, overrides default - just use "list" as is */ |
| 266 | } |
| 267 | |
| 268 | /* |
| 269 | * The supplied names may be a pattern-list. For the -list case, |
| 270 | * the patterns are applied above. For the +list and explicit list |
| 271 | * cases we need to do it now. |
| 272 | */ |
| 273 | ret = NULL((void *)0); |
| 274 | if ((patterns = opatterns = strdup(list)) == NULL((void *)0)) { |
| 275 | r = SSH_ERR_ALLOC_FAIL-2; |
| 276 | goto fail; |
| 277 | } |
| 278 | /* Apply positive (i.e. non-negated) patterns from the list */ |
| 279 | while ((cp = strsep(&patterns, ",")) != NULL((void *)0)) { |
| 280 | if (*cp == '!') { |
| 281 | /* negated matches are not supported here */ |
| 282 | r = SSH_ERR_INVALID_ARGUMENT-10; |
| 283 | goto fail; |
| 284 | } |
| 285 | free(matching); |
| 286 | if ((matching = match_filter_allowlist(all, cp)) == NULL((void *)0)) { |
| 287 | r = SSH_ERR_ALLOC_FAIL-2; |
| 288 | goto fail; |
| 289 | } |
| 290 | if ((tmp = kex_names_cat(ret, matching)) == NULL((void *)0)) { |
| 291 | r = SSH_ERR_ALLOC_FAIL-2; |
| 292 | goto fail; |
| 293 | } |
| 294 | free(ret); |
| 295 | ret = tmp; |
| 296 | } |
| 297 | if (ret == NULL((void *)0) || *ret == '\0') { |
| 298 | /* An empty name-list is an error */ |
| 299 | /* XXX better error code? */ |
| 300 | r = SSH_ERR_INVALID_ARGUMENT-10; |
| 301 | goto fail; |
| 302 | } |
| 303 | |
| 304 | /* success */ |
| 305 | *listp = ret; |
| 306 | ret = NULL((void *)0); |
| 307 | r = 0; |
| 308 | |
| 309 | fail: |
| 310 | free(matching); |
| 311 | free(opatterns); |
| 312 | free(list); |
| 313 | free(ret); |
| 314 | return r; |
| 315 | } |
| 316 | |
| 317 | /* |
| 318 | * Fill out a proposal array with dynamically allocated values, which may |
| 319 | * be modified as required for compatibility reasons. |
| 320 | * Any of the options may be NULL, in which case the default is used. |
| 321 | * Array contents must be freed by calling kex_proposal_free_entries. |
| 322 | */ |
| 323 | void |
| 324 | kex_proposal_populate_entries(struct ssh *ssh, char *prop[PROPOSAL_MAX], |
| 325 | const char *kexalgos, const char *ciphers, const char *macs, |
| 326 | const char *comp, const char *hkalgs) |
| 327 | { |
| 328 | const char *defpropserver[PROPOSAL_MAX] = { KEX_SERVER"sntrup761x25519-sha512@openssh.com," "curve25519-sha256," "curve25519-sha256@libssh.org," "ecdh-sha2-nistp256," "ecdh-sha2-nistp384," "ecdh-sha2-nistp521," "diffie-hellman-group-exchange-sha256," "diffie-hellman-group16-sha512," "diffie-hellman-group18-sha512," "diffie-hellman-group14-sha256" , "ssh-ed25519-cert-v01@openssh.com," "ecdsa-sha2-nistp256-cert-v01@openssh.com," "ecdsa-sha2-nistp384-cert-v01@openssh.com," "ecdsa-sha2-nistp521-cert-v01@openssh.com," "sk-ssh-ed25519-cert-v01@openssh.com," "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com," "rsa-sha2-512-cert-v01@openssh.com," "rsa-sha2-256-cert-v01@openssh.com," "ssh-ed25519," "ecdsa-sha2-nistp256," "ecdsa-sha2-nistp384," "ecdsa-sha2-nistp521," "sk-ssh-ed25519@openssh.com," "sk-ecdsa-sha2-nistp256@openssh.com," "rsa-sha2-512," "rsa-sha2-256", "chacha20-poly1305@openssh.com," "aes128-ctr,aes192-ctr,aes256-ctr," "aes128-gcm@openssh.com,aes256-gcm@openssh.com" , "chacha20-poly1305@openssh.com," "aes128-ctr,aes192-ctr,aes256-ctr," "aes128-gcm@openssh.com,aes256-gcm@openssh.com", "umac-64-etm@openssh.com," "umac-128-etm@openssh.com," "hmac-sha2-256-etm@openssh.com," "hmac-sha2-512-etm@openssh.com," "hmac-sha1-etm@openssh.com," "umac-64@openssh.com," "umac-128@openssh.com," "hmac-sha2-256," "hmac-sha2-512," "hmac-sha1", "umac-64-etm@openssh.com," "umac-128-etm@openssh.com," "hmac-sha2-256-etm@openssh.com," "hmac-sha2-512-etm@openssh.com," "hmac-sha1-etm@openssh.com," "umac-64@openssh.com," "umac-128@openssh.com," "hmac-sha2-256," "hmac-sha2-512," "hmac-sha1", "none,zlib@openssh.com" , "none,zlib@openssh.com", "", "" }; |
| 329 | const char *defpropclient[PROPOSAL_MAX] = { KEX_CLIENT"sntrup761x25519-sha512@openssh.com," "curve25519-sha256," "curve25519-sha256@libssh.org," "ecdh-sha2-nistp256," "ecdh-sha2-nistp384," "ecdh-sha2-nistp521," "diffie-hellman-group-exchange-sha256," "diffie-hellman-group16-sha512," "diffie-hellman-group18-sha512," "diffie-hellman-group14-sha256" , "ssh-ed25519-cert-v01@openssh.com," "ecdsa-sha2-nistp256-cert-v01@openssh.com," "ecdsa-sha2-nistp384-cert-v01@openssh.com," "ecdsa-sha2-nistp521-cert-v01@openssh.com," "sk-ssh-ed25519-cert-v01@openssh.com," "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com," "rsa-sha2-512-cert-v01@openssh.com," "rsa-sha2-256-cert-v01@openssh.com," "ssh-ed25519," "ecdsa-sha2-nistp256," "ecdsa-sha2-nistp384," "ecdsa-sha2-nistp521," "sk-ssh-ed25519@openssh.com," "sk-ecdsa-sha2-nistp256@openssh.com," "rsa-sha2-512," "rsa-sha2-256", "chacha20-poly1305@openssh.com," "aes128-ctr,aes192-ctr,aes256-ctr," "aes128-gcm@openssh.com,aes256-gcm@openssh.com" , "chacha20-poly1305@openssh.com," "aes128-ctr,aes192-ctr,aes256-ctr," "aes128-gcm@openssh.com,aes256-gcm@openssh.com", "umac-64-etm@openssh.com," "umac-128-etm@openssh.com," "hmac-sha2-256-etm@openssh.com," "hmac-sha2-512-etm@openssh.com," "hmac-sha1-etm@openssh.com," "umac-64@openssh.com," "umac-128@openssh.com," "hmac-sha2-256," "hmac-sha2-512," "hmac-sha1", "umac-64-etm@openssh.com," "umac-128-etm@openssh.com," "hmac-sha2-256-etm@openssh.com," "hmac-sha2-512-etm@openssh.com," "hmac-sha1-etm@openssh.com," "umac-64@openssh.com," "umac-128@openssh.com," "hmac-sha2-256," "hmac-sha2-512," "hmac-sha1", "none,zlib@openssh.com" , "none,zlib@openssh.com", "", "" }; |
| 330 | const char **defprop = ssh->kex->server ? defpropserver : defpropclient; |
| 331 | u_int i; |
| 332 | char *cp; |
| 333 | |
| 334 | if (prop == NULL((void *)0)) |
| 335 | fatal_f("proposal missing")sshfatal("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 335, 1 , SYSLOG_LEVEL_FATAL, ((void *)0), "proposal missing"); |
| 336 | |
| 337 | /* Append EXT_INFO signalling to KexAlgorithms */ |
| 338 | if (kexalgos == NULL((void *)0)) |
| 339 | kexalgos = defprop[PROPOSAL_KEX_ALGS]; |
| 340 | if ((cp = kex_names_cat(kexalgos, ssh->kex->server ? |
| 341 | "ext-info-s,kex-strict-s-v00@openssh.com" : |
| 342 | "ext-info-c,kex-strict-c-v00@openssh.com")) == NULL((void *)0)) |
| 343 | fatal_f("kex_names_cat")sshfatal("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 343, 1 , SYSLOG_LEVEL_FATAL, ((void *)0), "kex_names_cat"); |
| 344 | |
| 345 | for (i = 0; i < PROPOSAL_MAX; i++) { |
| 346 | switch(i) { |
| 347 | case PROPOSAL_KEX_ALGS: |
| 348 | prop[i] = compat_kex_proposal(ssh, cp); |
| 349 | break; |
| 350 | case PROPOSAL_ENC_ALGS_CTOS: |
| 351 | case PROPOSAL_ENC_ALGS_STOC: |
| 352 | prop[i] = xstrdup(ciphers ? ciphers : defprop[i]); |
| 353 | break; |
| 354 | case PROPOSAL_MAC_ALGS_CTOS: |
| 355 | case PROPOSAL_MAC_ALGS_STOC: |
| 356 | prop[i] = xstrdup(macs ? macs : defprop[i]); |
| 357 | break; |
| 358 | case PROPOSAL_COMP_ALGS_CTOS: |
| 359 | case PROPOSAL_COMP_ALGS_STOC: |
| 360 | prop[i] = xstrdup(comp ? comp : defprop[i]); |
| 361 | break; |
| 362 | case PROPOSAL_SERVER_HOST_KEY_ALGS: |
| 363 | prop[i] = xstrdup(hkalgs ? hkalgs : defprop[i]); |
| 364 | break; |
| 365 | default: |
| 366 | prop[i] = xstrdup(defprop[i]); |
| 367 | } |
| 368 | } |
| 369 | free(cp); |
| 370 | } |
| 371 | |
| 372 | void |
| 373 | kex_proposal_free_entries(char *prop[PROPOSAL_MAX]) |
| 374 | { |
| 375 | u_int i; |
| 376 | |
| 377 | for (i = 0; i < PROPOSAL_MAX; i++) |
| 378 | free(prop[i]); |
| 379 | } |
| 380 | |
| 381 | /* put algorithm proposal into buffer */ |
| 382 | int |
| 383 | kex_prop2buf(struct sshbuf *b, char *proposal[PROPOSAL_MAX]) |
| 384 | { |
| 385 | u_int i; |
| 386 | int r; |
| 387 | |
| 388 | sshbuf_reset(b); |
| 389 | |
| 390 | /* |
| 391 | * add a dummy cookie, the cookie will be overwritten by |
| 392 | * kex_send_kexinit(), each time a kexinit is set |
| 393 | */ |
| 394 | for (i = 0; i < KEX_COOKIE_LEN16; i++) { |
| 395 | if ((r = sshbuf_put_u8(b, 0)) != 0) |
| 396 | return r; |
| 397 | } |
| 398 | for (i = 0; i < PROPOSAL_MAX; i++) { |
| 399 | if ((r = sshbuf_put_cstring(b, proposal[i])) != 0) |
| 400 | return r; |
| 401 | } |
| 402 | if ((r = sshbuf_put_u8(b, 0)) != 0 || /* first_kex_packet_follows */ |
| 403 | (r = sshbuf_put_u32(b, 0)) != 0) /* uint32 reserved */ |
| 404 | return r; |
| 405 | return 0; |
| 406 | } |
| 407 | |
| 408 | /* parse buffer and return algorithm proposal */ |
| 409 | int |
| 410 | kex_buf2prop(struct sshbuf *raw, int *first_kex_follows, char ***propp) |
| 411 | { |
| 412 | struct sshbuf *b = NULL((void *)0); |
| 413 | u_char v; |
| 414 | u_int i; |
| 415 | char **proposal = NULL((void *)0); |
| 416 | int r; |
| 417 | |
| 418 | *propp = NULL((void *)0); |
| 419 | if ((proposal = calloc(PROPOSAL_MAX, sizeof(char *))) == NULL((void *)0)) |
| 420 | return SSH_ERR_ALLOC_FAIL-2; |
| 421 | if ((b = sshbuf_fromb(raw)) == NULL((void *)0)) { |
| 422 | r = SSH_ERR_ALLOC_FAIL-2; |
| 423 | goto out; |
| 424 | } |
| 425 | if ((r = sshbuf_consume(b, KEX_COOKIE_LEN16)) != 0) { /* skip cookie */ |
| 426 | error_fr(r, "consume cookie")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 426, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), "consume cookie"); |
| 427 | goto out; |
| 428 | } |
| 429 | /* extract kex init proposal strings */ |
| 430 | for (i = 0; i < PROPOSAL_MAX; i++) { |
| 431 | if ((r = sshbuf_get_cstring(b, &(proposal[i]), NULL((void *)0))) != 0) { |
| 432 | error_fr(r, "parse proposal %u", i)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 432, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), "parse proposal %u", i); |
| 433 | goto out; |
| 434 | } |
| 435 | debug2("%s: %s", proposal_names[i], proposal[i])sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 435, 0, SYSLOG_LEVEL_DEBUG2, ((void *)0), "%s: %s", proposal_names[i ], proposal[i]); |
| 436 | } |
| 437 | /* first kex follows / reserved */ |
| 438 | if ((r = sshbuf_get_u8(b, &v)) != 0 || /* first_kex_follows */ |
| 439 | (r = sshbuf_get_u32(b, &i)) != 0) { /* reserved */ |
| 440 | error_fr(r, "parse")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 440, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), "parse"); |
| 441 | goto out; |
| 442 | } |
| 443 | if (first_kex_follows != NULL((void *)0)) |
| 444 | *first_kex_follows = v; |
| 445 | debug2("first_kex_follows %d ", v)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 445, 0, SYSLOG_LEVEL_DEBUG2, ((void *)0), "first_kex_follows %d ", v ); |
| 446 | debug2("reserved %u ", i)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 446, 0, SYSLOG_LEVEL_DEBUG2, ((void *)0), "reserved %u ", i); |
| 447 | r = 0; |
| 448 | *propp = proposal; |
| 449 | out: |
| 450 | if (r != 0 && proposal != NULL((void *)0)) |
| 451 | kex_prop_free(proposal); |
| 452 | sshbuf_free(b); |
| 453 | return r; |
| 454 | } |
| 455 | |
| 456 | void |
| 457 | kex_prop_free(char **proposal) |
| 458 | { |
| 459 | u_int i; |
| 460 | |
| 461 | if (proposal == NULL((void *)0)) |
| 462 | return; |
| 463 | for (i = 0; i < PROPOSAL_MAX; i++) |
| 464 | free(proposal[i]); |
| 465 | free(proposal); |
| 466 | } |
| 467 | |
| 468 | int |
| 469 | kex_protocol_error(int type, u_int32_t seq, struct ssh *ssh) |
| 470 | { |
| 471 | int r; |
| 472 | |
| 473 | /* If in strict mode, any unexpected message is an error */ |
| 474 | if ((ssh->kex->flags & KEX_INITIAL0x0002) && ssh->kex->kex_strict) { |
| 475 | ssh_packet_disconnect(ssh, "strict KEX violation: " |
| 476 | "unexpected packet type %u (seqnr %u)", type, seq); |
| 477 | } |
| 478 | error_f("type %u seq %u", type, seq)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 478, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "type %u seq %u", type, seq ); |
| 479 | if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED3)) != 0 || |
| 480 | (r = sshpkt_put_u32(ssh, seq)) != 0 || |
| 481 | (r = sshpkt_send(ssh)) != 0) |
| 482 | return r; |
| 483 | return 0; |
| 484 | } |
| 485 | |
| 486 | static void |
| 487 | kex_reset_dispatch(struct ssh *ssh) |
| 488 | { |
| 489 | ssh_dispatch_range(ssh, SSH2_MSG_TRANSPORT_MIN1, |
| 490 | SSH2_MSG_TRANSPORT_MAX49, &kex_protocol_error); |
| 491 | } |
| 492 | |
| 493 | void |
| 494 | kex_set_server_sig_algs(struct ssh *ssh, const char *allowed_algs) |
| 495 | { |
| 496 | char *alg, *oalgs, *algs, *sigalgs; |
| 497 | const char *sigalg; |
| 498 | |
| 499 | /* |
| 500 | * NB. allowed algorithms may contain certificate algorithms that |
| 501 | * map to a specific plain signature type, e.g. |
| 502 | * rsa-sha2-512-cert-v01@openssh.com => rsa-sha2-512 |
| 503 | * We need to be careful here to match these, retain the mapping |
| 504 | * and only add each signature algorithm once. |
| 505 | */ |
| 506 | if ((sigalgs = sshkey_alg_list(0, 1, 1, ',')) == NULL((void *)0)) |
| 507 | fatal_f("sshkey_alg_list failed")sshfatal("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 507, 1 , SYSLOG_LEVEL_FATAL, ((void *)0), "sshkey_alg_list failed"); |
| 508 | oalgs = algs = xstrdup(allowed_algs); |
| 509 | free(ssh->kex->server_sig_algs); |
| 510 | ssh->kex->server_sig_algs = NULL((void *)0); |
| 511 | for ((alg = strsep(&algs, ",")); alg != NULL((void *)0) && *alg != '\0'; |
| 512 | (alg = strsep(&algs, ","))) { |
| 513 | if ((sigalg = sshkey_sigalg_by_name(alg)) == NULL((void *)0)) |
| 514 | continue; |
| 515 | if (!has_any_alg(sigalg, sigalgs)) |
| 516 | continue; |
| 517 | /* Don't add an algorithm twice. */ |
| 518 | if (ssh->kex->server_sig_algs != NULL((void *)0) && |
| 519 | has_any_alg(sigalg, ssh->kex->server_sig_algs)) |
| 520 | continue; |
| 521 | xextendf(&ssh->kex->server_sig_algs, ",", "%s", sigalg); |
| 522 | } |
| 523 | free(oalgs); |
| 524 | free(sigalgs); |
| 525 | if (ssh->kex->server_sig_algs == NULL((void *)0)) |
| 526 | ssh->kex->server_sig_algs = xstrdup(""); |
| 527 | } |
| 528 | |
| 529 | static int |
| 530 | kex_compose_ext_info_server(struct ssh *ssh, struct sshbuf *m) |
| 531 | { |
| 532 | int r; |
| 533 | |
| 534 | if (ssh->kex->server_sig_algs == NULL((void *)0) && |
| 535 | (ssh->kex->server_sig_algs = sshkey_alg_list(0, 1, 1, ',')) == NULL((void *)0)) |
| 536 | return SSH_ERR_ALLOC_FAIL-2; |
| 537 | if ((r = sshbuf_put_u32(m, 3)) != 0 || |
| 538 | (r = sshbuf_put_cstring(m, "server-sig-algs")) != 0 || |
| 539 | (r = sshbuf_put_cstring(m, ssh->kex->server_sig_algs)) != 0 || |
| 540 | (r = sshbuf_put_cstring(m, |
| 541 | "publickey-hostbound@openssh.com")) != 0 || |
| 542 | (r = sshbuf_put_cstring(m, "0")) != 0 || |
| 543 | (r = sshbuf_put_cstring(m, "ping@openssh.com")) != 0 || |
| 544 | (r = sshbuf_put_cstring(m, "0")) != 0) { |
| 545 | error_fr(r, "compose")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 545, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), "compose"); |
| 546 | return r; |
| 547 | } |
| 548 | return 0; |
| 549 | } |
| 550 | |
| 551 | static int |
| 552 | kex_compose_ext_info_client(struct ssh *ssh, struct sshbuf *m) |
| 553 | { |
| 554 | int r; |
| 555 | |
| 556 | if ((r = sshbuf_put_u32(m, 1)) != 0 || |
| 557 | (r = sshbuf_put_cstring(m, "ext-info-in-auth@openssh.com")) != 0 || |
| 558 | (r = sshbuf_put_cstring(m, "0")) != 0) { |
| 559 | error_fr(r, "compose")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 559, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), "compose"); |
| 560 | goto out; |
| 561 | } |
| 562 | /* success */ |
| 563 | r = 0; |
| 564 | out: |
| 565 | return r; |
| 566 | } |
| 567 | |
| 568 | static int |
| 569 | kex_maybe_send_ext_info(struct ssh *ssh) |
| 570 | { |
| 571 | int r; |
| 572 | struct sshbuf *m = NULL((void *)0); |
| 573 | |
| 574 | if ((ssh->kex->flags & KEX_INITIAL0x0002) == 0) |
| 575 | return 0; |
| 576 | if (!ssh->kex->ext_info_c && !ssh->kex->ext_info_s) |
| 577 | return 0; |
| 578 | |
| 579 | /* Compose EXT_INFO packet. */ |
| 580 | if ((m = sshbuf_new()) == NULL((void *)0)) |
| 581 | fatal_f("sshbuf_new failed")sshfatal("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 581, 1 , SYSLOG_LEVEL_FATAL, ((void *)0), "sshbuf_new failed"); |
| 582 | if (ssh->kex->ext_info_c && |
| 583 | (r = kex_compose_ext_info_server(ssh, m)) != 0) |
| 584 | goto fail; |
| 585 | if (ssh->kex->ext_info_s && |
| 586 | (r = kex_compose_ext_info_client(ssh, m)) != 0) |
| 587 | goto fail; |
| 588 | |
| 589 | /* Send the actual KEX_INFO packet */ |
| 590 | debug("Sending SSH2_MSG_EXT_INFO")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 590, 0, SYSLOG_LEVEL_DEBUG1, ((void *)0), "Sending SSH2_MSG_EXT_INFO" ); |
| 591 | if ((r = sshpkt_start(ssh, SSH2_MSG_EXT_INFO7)) != 0 || |
| 592 | (r = sshpkt_putb(ssh, m)) != 0 || |
| 593 | (r = sshpkt_send(ssh)) != 0) { |
| 594 | error_f("send EXT_INFO")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 594, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "send EXT_INFO"); |
| 595 | goto fail; |
| 596 | } |
| 597 | |
| 598 | r = 0; |
| 599 | |
| 600 | fail: |
| 601 | sshbuf_free(m); |
| 602 | return r; |
| 603 | } |
| 604 | |
| 605 | int |
| 606 | kex_server_update_ext_info(struct ssh *ssh) |
| 607 | { |
| 608 | int r; |
| 609 | |
| 610 | if ((ssh->kex->flags & KEX_HAS_EXT_INFO_IN_AUTH0x0040) == 0) |
| 611 | return 0; |
| 612 | |
| 613 | debug_f("Sending SSH2_MSG_EXT_INFO")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 613, 1, SYSLOG_LEVEL_DEBUG1, ((void *)0), "Sending SSH2_MSG_EXT_INFO" ); |
| 614 | if ((r = sshpkt_start(ssh, SSH2_MSG_EXT_INFO7)) != 0 || |
| 615 | (r = sshpkt_put_u32(ssh, 1)) != 0 || |
| 616 | (r = sshpkt_put_cstring(ssh, "server-sig-algs")) != 0 || |
| 617 | (r = sshpkt_put_cstring(ssh, ssh->kex->server_sig_algs)) != 0 || |
| 618 | (r = sshpkt_send(ssh)) != 0) { |
| 619 | error_f("send EXT_INFO")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 619, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "send EXT_INFO"); |
| 620 | return r; |
| 621 | } |
| 622 | return 0; |
| 623 | } |
| 624 | |
| 625 | int |
| 626 | kex_send_newkeys(struct ssh *ssh) |
| 627 | { |
| 628 | int r; |
| 629 | |
| 630 | kex_reset_dispatch(ssh); |
| 631 | if ((r = sshpkt_start(ssh, SSH2_MSG_NEWKEYS21)) != 0 || |
| 632 | (r = sshpkt_send(ssh)) != 0) |
| 633 | return r; |
| 634 | debug("SSH2_MSG_NEWKEYS sent")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 634, 0, SYSLOG_LEVEL_DEBUG1, ((void *)0), "SSH2_MSG_NEWKEYS sent"); |
| 635 | ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS21, &kex_input_newkeys); |
| 636 | if ((r = kex_maybe_send_ext_info(ssh)) != 0) |
| 637 | return r; |
| 638 | debug("expecting SSH2_MSG_NEWKEYS")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 638, 0, SYSLOG_LEVEL_DEBUG1, ((void *)0), "expecting SSH2_MSG_NEWKEYS" ); |
| 639 | return 0; |
| 640 | } |
| 641 | |
| 642 | /* Check whether an ext_info value contains the expected version string */ |
| 643 | static int |
| 644 | kex_ext_info_check_ver(struct kex *kex, const char *name, |
| 645 | const u_char *val, size_t len, const char *want_ver, u_int flag) |
| 646 | { |
| 647 | if (memchr(val, '\0', len) != NULL((void *)0)) { |
| 648 | error("SSH2_MSG_EXT_INFO: %s value contains nul byte", name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 648, 0, SYSLOG_LEVEL_ERROR, ((void *)0), "SSH2_MSG_EXT_INFO: %s value contains nul byte" , name); |
| 649 | return SSH_ERR_INVALID_FORMAT-4; |
| 650 | } |
| 651 | debug_f("%s=<%s>", name, val)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 651, 1, SYSLOG_LEVEL_DEBUG1, ((void *)0), "%s=<%s>", name, val ); |
| 652 | if (strcmp(val, want_ver) == 0) |
| 653 | kex->flags |= flag; |
| 654 | else |
| 655 | debug_f("unsupported version of %s extension", name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 655, 1, SYSLOG_LEVEL_DEBUG1, ((void *)0), "unsupported version of %s extension" , name); |
| 656 | return 0; |
| 657 | } |
| 658 | |
| 659 | static int |
| 660 | kex_ext_info_client_parse(struct ssh *ssh, const char *name, |
| 661 | const u_char *value, size_t vlen) |
| 662 | { |
| 663 | int r; |
| 664 | |
| 665 | /* NB. some messages are only accepted in the initial EXT_INFO */ |
| 666 | if (strcmp(name, "server-sig-algs") == 0) { |
| 667 | /* Ensure no \0 lurking in value */ |
| 668 | if (memchr(value, '\0', vlen) != NULL((void *)0)) { |
| 669 | error_f("nul byte in %s", name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 669, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "nul byte in %s", name); |
| 670 | return SSH_ERR_INVALID_FORMAT-4; |
| 671 | } |
| 672 | debug_f("%s=<%s>", name, value)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 672, 1, SYSLOG_LEVEL_DEBUG1, ((void *)0), "%s=<%s>", name, value ); |
| 673 | free(ssh->kex->server_sig_algs); |
| 674 | ssh->kex->server_sig_algs = xstrdup((const char *)value); |
| 675 | } else if (ssh->kex->ext_info_received == 1 && |
| 676 | strcmp(name, "publickey-hostbound@openssh.com") == 0) { |
| 677 | if ((r = kex_ext_info_check_ver(ssh->kex, name, value, vlen, |
| 678 | "0", KEX_HAS_PUBKEY_HOSTBOUND0x0004)) != 0) { |
| 679 | return r; |
| 680 | } |
| 681 | } else if (ssh->kex->ext_info_received == 1 && |
| 682 | strcmp(name, "ping@openssh.com") == 0) { |
| 683 | if ((r = kex_ext_info_check_ver(ssh->kex, name, value, vlen, |
| 684 | "0", KEX_HAS_PING0x0020)) != 0) { |
| 685 | return r; |
| 686 | } |
| 687 | } else |
| 688 | debug_f("%s (unrecognised)", name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 688, 1, SYSLOG_LEVEL_DEBUG1, ((void *)0), "%s (unrecognised)", name); |
| 689 | |
| 690 | return 0; |
| 691 | } |
| 692 | |
| 693 | static int |
| 694 | kex_ext_info_server_parse(struct ssh *ssh, const char *name, |
| 695 | const u_char *value, size_t vlen) |
| 696 | { |
| 697 | int r; |
| 698 | |
| 699 | if (strcmp(name, "ext-info-in-auth@openssh.com") == 0) { |
| 700 | if ((r = kex_ext_info_check_ver(ssh->kex, name, value, vlen, |
| 701 | "0", KEX_HAS_EXT_INFO_IN_AUTH0x0040)) != 0) { |
| 702 | return r; |
| 703 | } |
| 704 | } else |
| 705 | debug_f("%s (unrecognised)", name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 705, 1, SYSLOG_LEVEL_DEBUG1, ((void *)0), "%s (unrecognised)", name); |
| 706 | return 0; |
| 707 | } |
| 708 | |
| 709 | int |
| 710 | kex_input_ext_info(int type, u_int32_t seq, struct ssh *ssh) |
| 711 | { |
| 712 | struct kex *kex = ssh->kex; |
| 713 | const int max_ext_info = kex->server ? 1 : 2; |
| 714 | u_int32_t i, ninfo; |
| 715 | char *name; |
| 716 | u_char *val; |
| 717 | size_t vlen; |
| 718 | int r; |
| 719 | |
| 720 | debug("SSH2_MSG_EXT_INFO received")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 720, 0, SYSLOG_LEVEL_DEBUG1, ((void *)0), "SSH2_MSG_EXT_INFO received" ); |
| 721 | if (++kex->ext_info_received > max_ext_info) { |
| 722 | error("too many SSH2_MSG_EXT_INFO messages sent by peer")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 722, 0, SYSLOG_LEVEL_ERROR, ((void *)0), "too many SSH2_MSG_EXT_INFO messages sent by peer" ); |
| 723 | return dispatch_protocol_error(type, seq, ssh); |
| 724 | } |
| 725 | ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO7, &kex_protocol_error); |
| 726 | if ((r = sshpkt_get_u32(ssh, &ninfo)) != 0) |
| 727 | return r; |
| 728 | if (ninfo >= 1024) { |
| 729 | error("SSH2_MSG_EXT_INFO with too many entries, expected "sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 730, 0, SYSLOG_LEVEL_ERROR, ((void *)0), "SSH2_MSG_EXT_INFO with too many entries, expected " "<=1024, received %u", ninfo) |
| 730 | "<=1024, received %u", ninfo)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 730, 0, SYSLOG_LEVEL_ERROR, ((void *)0), "SSH2_MSG_EXT_INFO with too many entries, expected " "<=1024, received %u", ninfo); |
| 731 | return dispatch_protocol_error(type, seq, ssh); |
| 732 | } |
| 733 | for (i = 0; i < ninfo; i++) { |
| 734 | if ((r = sshpkt_get_cstring(ssh, &name, NULL((void *)0))) != 0) |
| 735 | return r; |
| 736 | if ((r = sshpkt_get_string(ssh, &val, &vlen)) != 0) { |
| 737 | free(name); |
| 738 | return r; |
| 739 | } |
| 740 | debug3_f("extension %s", name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 740, 1, SYSLOG_LEVEL_DEBUG3, ((void *)0), "extension %s", name); |
| 741 | if (kex->server) { |
| 742 | if ((r = kex_ext_info_server_parse(ssh, name, |
| 743 | val, vlen)) != 0) |
| 744 | return r; |
| 745 | } else { |
| 746 | if ((r = kex_ext_info_client_parse(ssh, name, |
| 747 | val, vlen)) != 0) |
| 748 | return r; |
| 749 | } |
| 750 | free(name); |
| 751 | free(val); |
| 752 | } |
| 753 | return sshpkt_get_end(ssh); |
| 754 | } |
| 755 | |
| 756 | static int |
| 757 | kex_input_newkeys(int type, u_int32_t seq, struct ssh *ssh) |
| 758 | { |
| 759 | struct kex *kex = ssh->kex; |
| 760 | int r, initial = (kex->flags & KEX_INITIAL0x0002) != 0; |
| 761 | char *cp, **prop; |
| 762 | |
| 763 | debug("SSH2_MSG_NEWKEYS received")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 763, 0, SYSLOG_LEVEL_DEBUG1, ((void *)0), "SSH2_MSG_NEWKEYS received" ); |
| 764 | if (kex->ext_info_c && initial) |
| 765 | ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO7, &kex_input_ext_info); |
| 766 | ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS21, &kex_protocol_error); |
| 767 | ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT20, &kex_input_kexinit); |
| 768 | if ((r = sshpkt_get_end(ssh)) != 0) |
| 769 | return r; |
| 770 | if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0) |
| 771 | return r; |
| 772 | if (initial) { |
| 773 | /* Remove initial KEX signalling from proposal for rekeying */ |
| 774 | if ((r = kex_buf2prop(kex->my, NULL((void *)0), &prop)) != 0) |
| 775 | return r; |
| 776 | if ((cp = match_filter_denylist(prop[PROPOSAL_KEX_ALGS], |
| 777 | kex->server ? |
| 778 | "ext-info-s,kex-strict-s-v00@openssh.com" : |
| 779 | "ext-info-c,kex-strict-c-v00@openssh.com")) == NULL((void *)0)) { |
| 780 | error_f("match_filter_denylist failed")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 780, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "match_filter_denylist failed" ); |
| 781 | goto fail; |
| 782 | } |
| 783 | free(prop[PROPOSAL_KEX_ALGS]); |
| 784 | prop[PROPOSAL_KEX_ALGS] = cp; |
| 785 | if ((r = kex_prop2buf(ssh->kex->my, prop)) != 0) { |
Although the value stored to 'r' is used in the enclosing expression, the value is never actually read from 'r' | |
| 786 | error_f("kex_prop2buf failed")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 786, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "kex_prop2buf failed"); |
| 787 | fail: |
| 788 | kex_proposal_free_entries(prop); |
| 789 | free(prop); |
| 790 | return SSH_ERR_INTERNAL_ERROR-1; |
| 791 | } |
| 792 | kex_proposal_free_entries(prop); |
| 793 | free(prop); |
| 794 | } |
| 795 | kex->done = 1; |
| 796 | kex->flags &= ~KEX_INITIAL0x0002; |
| 797 | sshbuf_reset(kex->peer); |
| 798 | kex->flags &= ~KEX_INIT_SENT0x0001; |
| 799 | free(kex->name); |
| 800 | kex->name = NULL((void *)0); |
| 801 | return 0; |
| 802 | } |
| 803 | |
| 804 | int |
| 805 | kex_send_kexinit(struct ssh *ssh) |
| 806 | { |
| 807 | u_char *cookie; |
| 808 | struct kex *kex = ssh->kex; |
| 809 | int r; |
| 810 | |
| 811 | if (kex == NULL((void *)0)) { |
| 812 | error_f("no kex")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 812, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "no kex"); |
| 813 | return SSH_ERR_INTERNAL_ERROR-1; |
| 814 | } |
| 815 | if (kex->flags & KEX_INIT_SENT0x0001) |
| 816 | return 0; |
| 817 | kex->done = 0; |
| 818 | |
| 819 | /* generate a random cookie */ |
| 820 | if (sshbuf_len(kex->my) < KEX_COOKIE_LEN16) { |
| 821 | error_f("bad kex length: %zu < %d",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 822, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "bad kex length: %zu < %d" , sshbuf_len(kex->my), 16) |
| 822 | sshbuf_len(kex->my), KEX_COOKIE_LEN)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 822, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "bad kex length: %zu < %d" , sshbuf_len(kex->my), 16); |
| 823 | return SSH_ERR_INVALID_FORMAT-4; |
| 824 | } |
| 825 | if ((cookie = sshbuf_mutable_ptr(kex->my)) == NULL((void *)0)) { |
| 826 | error_f("buffer error")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 826, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "buffer error"); |
| 827 | return SSH_ERR_INTERNAL_ERROR-1; |
| 828 | } |
| 829 | arc4random_buf(cookie, KEX_COOKIE_LEN16); |
| 830 | |
| 831 | if ((r = sshpkt_start(ssh, SSH2_MSG_KEXINIT20)) != 0 || |
| 832 | (r = sshpkt_putb(ssh, kex->my)) != 0 || |
| 833 | (r = sshpkt_send(ssh)) != 0) { |
| 834 | error_fr(r, "compose reply")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 834, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), "compose reply"); |
| 835 | return r; |
| 836 | } |
| 837 | debug("SSH2_MSG_KEXINIT sent")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 837, 0, SYSLOG_LEVEL_DEBUG1, ((void *)0), "SSH2_MSG_KEXINIT sent"); |
| 838 | kex->flags |= KEX_INIT_SENT0x0001; |
| 839 | return 0; |
| 840 | } |
| 841 | |
| 842 | int |
| 843 | kex_input_kexinit(int type, u_int32_t seq, struct ssh *ssh) |
| 844 | { |
| 845 | struct kex *kex = ssh->kex; |
| 846 | const u_char *ptr; |
| 847 | u_int i; |
| 848 | size_t dlen; |
| 849 | int r; |
| 850 | |
| 851 | debug("SSH2_MSG_KEXINIT received")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 851, 0, SYSLOG_LEVEL_DEBUG1, ((void *)0), "SSH2_MSG_KEXINIT received" ); |
| 852 | if (kex == NULL((void *)0)) { |
| 853 | error_f("no kex")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 853, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "no kex"); |
| 854 | return SSH_ERR_INTERNAL_ERROR-1; |
| 855 | } |
| 856 | ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT20, &kex_protocol_error); |
| 857 | ptr = sshpkt_ptr(ssh, &dlen); |
| 858 | if ((r = sshbuf_put(kex->peer, ptr, dlen)) != 0) |
| 859 | return r; |
| 860 | |
| 861 | /* discard packet */ |
| 862 | for (i = 0; i < KEX_COOKIE_LEN16; i++) { |
| 863 | if ((r = sshpkt_get_u8(ssh, NULL((void *)0))) != 0) { |
| 864 | error_fr(r, "discard cookie")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 864, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), "discard cookie"); |
| 865 | return r; |
| 866 | } |
| 867 | } |
| 868 | for (i = 0; i < PROPOSAL_MAX; i++) { |
| 869 | if ((r = sshpkt_get_string(ssh, NULL((void *)0), NULL((void *)0))) != 0) { |
| 870 | error_fr(r, "discard proposal")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 870, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), "discard proposal"); |
| 871 | return r; |
| 872 | } |
| 873 | } |
| 874 | /* |
| 875 | * XXX RFC4253 sec 7: "each side MAY guess" - currently no supported |
| 876 | * KEX method has the server move first, but a server might be using |
| 877 | * a custom method or one that we otherwise don't support. We should |
| 878 | * be prepared to remember first_kex_follows here so we can eat a |
| 879 | * packet later. |
| 880 | * XXX2 - RFC4253 is kind of ambiguous on what first_kex_follows means |
| 881 | * for cases where the server *doesn't* go first. I guess we should |
| 882 | * ignore it when it is set for these cases, which is what we do now. |
| 883 | */ |
| 884 | if ((r = sshpkt_get_u8(ssh, NULL((void *)0))) != 0 || /* first_kex_follows */ |
| 885 | (r = sshpkt_get_u32(ssh, NULL((void *)0))) != 0 || /* reserved */ |
| 886 | (r = sshpkt_get_end(ssh)) != 0) |
| 887 | return r; |
| 888 | |
| 889 | if (!(kex->flags & KEX_INIT_SENT0x0001)) |
| 890 | if ((r = kex_send_kexinit(ssh)) != 0) |
| 891 | return r; |
| 892 | if ((r = kex_choose_conf(ssh, seq)) != 0) |
| 893 | return r; |
| 894 | |
| 895 | if (kex->kex_type < KEX_MAX && kex->kex[kex->kex_type] != NULL((void *)0)) |
| 896 | return (kex->kex[kex->kex_type])(ssh); |
| 897 | |
| 898 | error_f("unknown kex type %u", kex->kex_type)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 898, 1, SYSLOG_LEVEL_ERROR, ((void *)0), "unknown kex type %u", kex-> kex_type); |
| 899 | return SSH_ERR_INTERNAL_ERROR-1; |
| 900 | } |
| 901 | |
| 902 | struct kex * |
| 903 | kex_new(void) |
| 904 | { |
| 905 | struct kex *kex; |
| 906 | |
| 907 | if ((kex = calloc(1, sizeof(*kex))) == NULL((void *)0) || |
| 908 | (kex->peer = sshbuf_new()) == NULL((void *)0) || |
| 909 | (kex->my = sshbuf_new()) == NULL((void *)0) || |
| 910 | (kex->client_version = sshbuf_new()) == NULL((void *)0) || |
| 911 | (kex->server_version = sshbuf_new()) == NULL((void *)0) || |
| 912 | (kex->session_id = sshbuf_new()) == NULL((void *)0)) { |
| 913 | kex_free(kex); |
| 914 | return NULL((void *)0); |
| 915 | } |
| 916 | return kex; |
| 917 | } |
| 918 | |
| 919 | void |
| 920 | kex_free_newkeys(struct newkeys *newkeys) |
| 921 | { |
| 922 | if (newkeys == NULL((void *)0)) |
| 923 | return; |
| 924 | if (newkeys->enc.key) { |
| 925 | explicit_bzero(newkeys->enc.key, newkeys->enc.key_len); |
| 926 | free(newkeys->enc.key); |
| 927 | newkeys->enc.key = NULL((void *)0); |
| 928 | } |
| 929 | if (newkeys->enc.iv) { |
| 930 | explicit_bzero(newkeys->enc.iv, newkeys->enc.iv_len); |
| 931 | free(newkeys->enc.iv); |
| 932 | newkeys->enc.iv = NULL((void *)0); |
| 933 | } |
| 934 | free(newkeys->enc.name); |
| 935 | explicit_bzero(&newkeys->enc, sizeof(newkeys->enc)); |
| 936 | free(newkeys->comp.name); |
| 937 | explicit_bzero(&newkeys->comp, sizeof(newkeys->comp)); |
| 938 | mac_clear(&newkeys->mac); |
| 939 | if (newkeys->mac.key) { |
| 940 | explicit_bzero(newkeys->mac.key, newkeys->mac.key_len); |
| 941 | free(newkeys->mac.key); |
| 942 | newkeys->mac.key = NULL((void *)0); |
| 943 | } |
| 944 | free(newkeys->mac.name); |
| 945 | explicit_bzero(&newkeys->mac, sizeof(newkeys->mac)); |
| 946 | freezero(newkeys, sizeof(*newkeys)); |
| 947 | } |
| 948 | |
| 949 | void |
| 950 | kex_free(struct kex *kex) |
| 951 | { |
| 952 | u_int mode; |
| 953 | |
| 954 | if (kex == NULL((void *)0)) |
| 955 | return; |
| 956 | |
| 957 | #ifdef WITH_OPENSSL1 |
| 958 | DH_free(kex->dh); |
| 959 | EC_KEY_free(kex->ec_client_key); |
| 960 | #endif |
| 961 | for (mode = 0; mode < MODE_MAX; mode++) { |
| 962 | kex_free_newkeys(kex->newkeys[mode]); |
| 963 | kex->newkeys[mode] = NULL((void *)0); |
| 964 | } |
| 965 | sshbuf_free(kex->peer); |
| 966 | sshbuf_free(kex->my); |
| 967 | sshbuf_free(kex->client_version); |
| 968 | sshbuf_free(kex->server_version); |
| 969 | sshbuf_free(kex->client_pub); |
| 970 | sshbuf_free(kex->session_id); |
| 971 | sshbuf_free(kex->initial_sig); |
| 972 | sshkey_free(kex->initial_hostkey); |
| 973 | free(kex->failed_choice); |
| 974 | free(kex->hostkey_alg); |
| 975 | free(kex->name); |
| 976 | free(kex); |
| 977 | } |
| 978 | |
| 979 | int |
| 980 | kex_ready(struct ssh *ssh, char *proposal[PROPOSAL_MAX]) |
| 981 | { |
| 982 | int r; |
| 983 | |
| 984 | if ((r = kex_prop2buf(ssh->kex->my, proposal)) != 0) |
| 985 | return r; |
| 986 | ssh->kex->flags = KEX_INITIAL0x0002; |
| 987 | kex_reset_dispatch(ssh); |
| 988 | ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT20, &kex_input_kexinit); |
| 989 | return 0; |
| 990 | } |
| 991 | |
| 992 | int |
| 993 | kex_setup(struct ssh *ssh, char *proposal[PROPOSAL_MAX]) |
| 994 | { |
| 995 | int r; |
| 996 | |
| 997 | if ((r = kex_ready(ssh, proposal)) != 0) |
| 998 | return r; |
| 999 | if ((r = kex_send_kexinit(ssh)) != 0) { /* we start */ |
| 1000 | kex_free(ssh->kex); |
| 1001 | ssh->kex = NULL((void *)0); |
| 1002 | return r; |
| 1003 | } |
| 1004 | return 0; |
| 1005 | } |
| 1006 | |
| 1007 | /* |
| 1008 | * Request key re-exchange, returns 0 on success or a ssherr.h error |
| 1009 | * code otherwise. Must not be called if KEX is incomplete or in-progress. |
| 1010 | */ |
| 1011 | int |
| 1012 | kex_start_rekex(struct ssh *ssh) |
| 1013 | { |
| 1014 | if (ssh->kex == NULL((void *)0)) { |
| 1015 | error_f("no kex")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1015, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "no kex"); |
| 1016 | return SSH_ERR_INTERNAL_ERROR-1; |
| 1017 | } |
| 1018 | if (ssh->kex->done == 0) { |
| 1019 | error_f("requested twice")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1019, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "requested twice"); |
| 1020 | return SSH_ERR_INTERNAL_ERROR-1; |
| 1021 | } |
| 1022 | ssh->kex->done = 0; |
| 1023 | return kex_send_kexinit(ssh); |
| 1024 | } |
| 1025 | |
| 1026 | static int |
| 1027 | choose_enc(struct sshenc *enc, char *client, char *server) |
| 1028 | { |
| 1029 | char *name = match_list(client, server, NULL((void *)0)); |
| 1030 | |
| 1031 | if (name == NULL((void *)0)) |
| 1032 | return SSH_ERR_NO_CIPHER_ALG_MATCH-31; |
| 1033 | if ((enc->cipher = cipher_by_name(name)) == NULL((void *)0)) { |
| 1034 | error_f("unsupported cipher %s", name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1034, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "unsupported cipher %s", name ); |
| 1035 | free(name); |
| 1036 | return SSH_ERR_INTERNAL_ERROR-1; |
| 1037 | } |
| 1038 | enc->name = name; |
| 1039 | enc->enabled = 0; |
| 1040 | enc->iv = NULL((void *)0); |
| 1041 | enc->iv_len = cipher_ivlen(enc->cipher); |
| 1042 | enc->key = NULL((void *)0); |
| 1043 | enc->key_len = cipher_keylen(enc->cipher); |
| 1044 | enc->block_size = cipher_blocksize(enc->cipher); |
| 1045 | return 0; |
| 1046 | } |
| 1047 | |
| 1048 | static int |
| 1049 | choose_mac(struct ssh *ssh, struct sshmac *mac, char *client, char *server) |
| 1050 | { |
| 1051 | char *name = match_list(client, server, NULL((void *)0)); |
| 1052 | |
| 1053 | if (name == NULL((void *)0)) |
| 1054 | return SSH_ERR_NO_MAC_ALG_MATCH-32; |
| 1055 | if (mac_setup(mac, name) < 0) { |
| 1056 | error_f("unsupported MAC %s", name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1056, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "unsupported MAC %s", name ); |
| 1057 | free(name); |
| 1058 | return SSH_ERR_INTERNAL_ERROR-1; |
| 1059 | } |
| 1060 | mac->name = name; |
| 1061 | mac->key = NULL((void *)0); |
| 1062 | mac->enabled = 0; |
| 1063 | return 0; |
| 1064 | } |
| 1065 | |
| 1066 | static int |
| 1067 | choose_comp(struct sshcomp *comp, char *client, char *server) |
| 1068 | { |
| 1069 | char *name = match_list(client, server, NULL((void *)0)); |
| 1070 | |
| 1071 | if (name == NULL((void *)0)) |
| 1072 | return SSH_ERR_NO_COMPRESS_ALG_MATCH-33; |
| 1073 | #ifdef WITH_ZLIB1 |
| 1074 | if (strcmp(name, "zlib@openssh.com") == 0) { |
| 1075 | comp->type = COMP_DELAYED2; |
| 1076 | } else if (strcmp(name, "zlib") == 0) { |
| 1077 | comp->type = COMP_ZLIB1; |
| 1078 | } else |
| 1079 | #endif /* WITH_ZLIB */ |
| 1080 | if (strcmp(name, "none") == 0) { |
| 1081 | comp->type = COMP_NONE0; |
| 1082 | } else { |
| 1083 | error_f("unsupported compression scheme %s", name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1083, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "unsupported compression scheme %s" , name); |
| 1084 | free(name); |
| 1085 | return SSH_ERR_INTERNAL_ERROR-1; |
| 1086 | } |
| 1087 | comp->name = name; |
| 1088 | return 0; |
| 1089 | } |
| 1090 | |
| 1091 | static int |
| 1092 | choose_kex(struct kex *k, char *client, char *server) |
| 1093 | { |
| 1094 | const struct kexalg *kexalg; |
| 1095 | |
| 1096 | k->name = match_list(client, server, NULL((void *)0)); |
| 1097 | |
| 1098 | debug("kex: algorithm: %s", k->name ? k->name : "(no match)")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1098, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "kex: algorithm: %s", k-> name ? k->name : "(no match)"); |
| 1099 | if (k->name == NULL((void *)0)) |
| 1100 | return SSH_ERR_NO_KEX_ALG_MATCH-34; |
| 1101 | if ((kexalg = kex_alg_by_name(k->name)) == NULL((void *)0)) { |
| 1102 | error_f("unsupported KEX method %s", k->name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1102, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "unsupported KEX method %s" , k->name); |
| 1103 | return SSH_ERR_INTERNAL_ERROR-1; |
| 1104 | } |
| 1105 | k->kex_type = kexalg->type; |
| 1106 | k->hash_alg = kexalg->hash_alg; |
| 1107 | k->ec_nid = kexalg->ec_nid; |
| 1108 | return 0; |
| 1109 | } |
| 1110 | |
| 1111 | static int |
| 1112 | choose_hostkeyalg(struct kex *k, char *client, char *server) |
| 1113 | { |
| 1114 | free(k->hostkey_alg); |
| 1115 | k->hostkey_alg = match_list(client, server, NULL((void *)0)); |
| 1116 | |
| 1117 | debug("kex: host key algorithm: %s",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1118, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "kex: host key algorithm: %s" , k->hostkey_alg ? k->hostkey_alg : "(no match)") |
| 1118 | k->hostkey_alg ? k->hostkey_alg : "(no match)")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1118, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "kex: host key algorithm: %s" , k->hostkey_alg ? k->hostkey_alg : "(no match)"); |
| 1119 | if (k->hostkey_alg == NULL((void *)0)) |
| 1120 | return SSH_ERR_NO_HOSTKEY_ALG_MATCH-35; |
| 1121 | k->hostkey_type = sshkey_type_from_name(k->hostkey_alg); |
| 1122 | if (k->hostkey_type == KEY_UNSPEC) { |
| 1123 | error_f("unsupported hostkey algorithm %s", k->hostkey_alg)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1123, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "unsupported hostkey algorithm %s" , k->hostkey_alg); |
| 1124 | return SSH_ERR_INTERNAL_ERROR-1; |
| 1125 | } |
| 1126 | k->hostkey_nid = sshkey_ecdsa_nid_from_name(k->hostkey_alg); |
| 1127 | return 0; |
| 1128 | } |
| 1129 | |
| 1130 | static int |
| 1131 | proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX]) |
| 1132 | { |
| 1133 | static int check[] = { |
| 1134 | PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1 |
| 1135 | }; |
| 1136 | int *idx; |
| 1137 | char *p; |
| 1138 | |
| 1139 | for (idx = &check[0]; *idx != -1; idx++) { |
| 1140 | if ((p = strchr(my[*idx], ',')) != NULL((void *)0)) |
| 1141 | *p = '\0'; |
| 1142 | if ((p = strchr(peer[*idx], ',')) != NULL((void *)0)) |
| 1143 | *p = '\0'; |
| 1144 | if (strcmp(my[*idx], peer[*idx]) != 0) { |
| 1145 | debug2("proposal mismatch: my %s peer %s",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1146, 0 , SYSLOG_LEVEL_DEBUG2, ((void *)0), "proposal mismatch: my %s peer %s" , my[*idx], peer[*idx]) |
| 1146 | my[*idx], peer[*idx])sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1146, 0 , SYSLOG_LEVEL_DEBUG2, ((void *)0), "proposal mismatch: my %s peer %s" , my[*idx], peer[*idx]); |
| 1147 | return (0); |
| 1148 | } |
| 1149 | } |
| 1150 | debug2("proposals match")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1150, 0 , SYSLOG_LEVEL_DEBUG2, ((void *)0), "proposals match"); |
| 1151 | return (1); |
| 1152 | } |
| 1153 | |
| 1154 | static int |
| 1155 | kexalgs_contains(char **peer, const char *ext) |
| 1156 | { |
| 1157 | return has_any_alg(peer[PROPOSAL_KEX_ALGS], ext); |
| 1158 | } |
| 1159 | |
| 1160 | static int |
| 1161 | kex_choose_conf(struct ssh *ssh, uint32_t seq) |
| 1162 | { |
| 1163 | struct kex *kex = ssh->kex; |
| 1164 | struct newkeys *newkeys; |
| 1165 | char **my = NULL((void *)0), **peer = NULL((void *)0); |
| 1166 | char **cprop, **sprop; |
| 1167 | int nenc, nmac, ncomp; |
| 1168 | u_int mode, ctos, need, dh_need, authlen; |
| 1169 | int r, first_kex_follows; |
| 1170 | |
| 1171 | debug2("local %s KEXINIT proposal", kex->server ? "server" : "client")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1171, 0 , SYSLOG_LEVEL_DEBUG2, ((void *)0), "local %s KEXINIT proposal" , kex->server ? "server" : "client"); |
| 1172 | if ((r = kex_buf2prop(kex->my, NULL((void *)0), &my)) != 0) |
| 1173 | goto out; |
| 1174 | debug2("peer %s KEXINIT proposal", kex->server ? "client" : "server")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1174, 0 , SYSLOG_LEVEL_DEBUG2, ((void *)0), "peer %s KEXINIT proposal" , kex->server ? "client" : "server"); |
| 1175 | if ((r = kex_buf2prop(kex->peer, &first_kex_follows, &peer)) != 0) |
| 1176 | goto out; |
| 1177 | |
| 1178 | if (kex->server) { |
| 1179 | cprop=peer; |
| 1180 | sprop=my; |
| 1181 | } else { |
| 1182 | cprop=my; |
| 1183 | sprop=peer; |
| 1184 | } |
| 1185 | |
| 1186 | /* Check whether peer supports ext_info/kex_strict */ |
| 1187 | if ((kex->flags & KEX_INITIAL0x0002) != 0) { |
| 1188 | if (kex->server) { |
| 1189 | kex->ext_info_c = kexalgs_contains(peer, "ext-info-c"); |
| 1190 | kex->kex_strict = kexalgs_contains(peer, |
| 1191 | "kex-strict-c-v00@openssh.com"); |
| 1192 | } else { |
| 1193 | kex->ext_info_s = kexalgs_contains(peer, "ext-info-s"); |
| 1194 | kex->kex_strict = kexalgs_contains(peer, |
| 1195 | "kex-strict-s-v00@openssh.com"); |
| 1196 | } |
| 1197 | if (kex->kex_strict) { |
| 1198 | debug3_f("will use strict KEX ordering")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1198, 1 , SYSLOG_LEVEL_DEBUG3, ((void *)0), "will use strict KEX ordering" ); |
| 1199 | if (seq != 0) |
| 1200 | ssh_packet_disconnect(ssh, |
| 1201 | "strict KEX violation: " |
| 1202 | "KEXINIT was not the first packet"); |
| 1203 | } |
| 1204 | } |
| 1205 | |
| 1206 | /* Check whether client supports rsa-sha2 algorithms */ |
| 1207 | if (kex->server && (kex->flags & KEX_INITIAL0x0002)) { |
| 1208 | if (has_any_alg(peer[PROPOSAL_SERVER_HOST_KEY_ALGS], |
| 1209 | "rsa-sha2-256,rsa-sha2-256-cert-v01@openssh.com")) |
| 1210 | kex->flags |= KEX_RSA_SHA2_256_SUPPORTED0x0008; |
| 1211 | if (has_any_alg(peer[PROPOSAL_SERVER_HOST_KEY_ALGS], |
| 1212 | "rsa-sha2-512,rsa-sha2-512-cert-v01@openssh.com")) |
| 1213 | kex->flags |= KEX_RSA_SHA2_512_SUPPORTED0x0010; |
| 1214 | } |
| 1215 | |
| 1216 | /* Algorithm Negotiation */ |
| 1217 | if ((r = choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], |
| 1218 | sprop[PROPOSAL_KEX_ALGS])) != 0) { |
| 1219 | kex->failed_choice = peer[PROPOSAL_KEX_ALGS]; |
| 1220 | peer[PROPOSAL_KEX_ALGS] = NULL((void *)0); |
| 1221 | goto out; |
| 1222 | } |
| 1223 | if ((r = choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS], |
| 1224 | sprop[PROPOSAL_SERVER_HOST_KEY_ALGS])) != 0) { |
| 1225 | kex->failed_choice = peer[PROPOSAL_SERVER_HOST_KEY_ALGS]; |
| 1226 | peer[PROPOSAL_SERVER_HOST_KEY_ALGS] = NULL((void *)0); |
| 1227 | goto out; |
| 1228 | } |
| 1229 | for (mode = 0; mode < MODE_MAX; mode++) { |
| 1230 | if ((newkeys = calloc(1, sizeof(*newkeys))) == NULL((void *)0)) { |
| 1231 | r = SSH_ERR_ALLOC_FAIL-2; |
| 1232 | goto out; |
| 1233 | } |
| 1234 | kex->newkeys[mode] = newkeys; |
| 1235 | ctos = (!kex->server && mode == MODE_OUT) || |
| 1236 | (kex->server && mode == MODE_IN); |
| 1237 | nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC; |
| 1238 | nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC; |
| 1239 | ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC; |
| 1240 | if ((r = choose_enc(&newkeys->enc, cprop[nenc], |
| 1241 | sprop[nenc])) != 0) { |
| 1242 | kex->failed_choice = peer[nenc]; |
| 1243 | peer[nenc] = NULL((void *)0); |
| 1244 | goto out; |
| 1245 | } |
| 1246 | authlen = cipher_authlen(newkeys->enc.cipher); |
| 1247 | /* ignore mac for authenticated encryption */ |
| 1248 | if (authlen == 0 && |
| 1249 | (r = choose_mac(ssh, &newkeys->mac, cprop[nmac], |
| 1250 | sprop[nmac])) != 0) { |
| 1251 | kex->failed_choice = peer[nmac]; |
| 1252 | peer[nmac] = NULL((void *)0); |
| 1253 | goto out; |
| 1254 | } |
| 1255 | if ((r = choose_comp(&newkeys->comp, cprop[ncomp], |
| 1256 | sprop[ncomp])) != 0) { |
| 1257 | kex->failed_choice = peer[ncomp]; |
| 1258 | peer[ncomp] = NULL((void *)0); |
| 1259 | goto out; |
| 1260 | } |
| 1261 | debug("kex: %s cipher: %s MAC: %s compression: %s",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1265, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "kex: %s cipher: %s MAC: %s compression: %s" , ctos ? "client->server" : "server->client", newkeys-> enc.name, authlen == 0 ? newkeys->mac.name : "<implicit>" , newkeys->comp.name) |
| 1262 | ctos ? "client->server" : "server->client",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1265, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "kex: %s cipher: %s MAC: %s compression: %s" , ctos ? "client->server" : "server->client", newkeys-> enc.name, authlen == 0 ? newkeys->mac.name : "<implicit>" , newkeys->comp.name) |
| 1263 | newkeys->enc.name,sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1265, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "kex: %s cipher: %s MAC: %s compression: %s" , ctos ? "client->server" : "server->client", newkeys-> enc.name, authlen == 0 ? newkeys->mac.name : "<implicit>" , newkeys->comp.name) |
| 1264 | authlen == 0 ? newkeys->mac.name : "<implicit>",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1265, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "kex: %s cipher: %s MAC: %s compression: %s" , ctos ? "client->server" : "server->client", newkeys-> enc.name, authlen == 0 ? newkeys->mac.name : "<implicit>" , newkeys->comp.name) |
| 1265 | newkeys->comp.name)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1265, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "kex: %s cipher: %s MAC: %s compression: %s" , ctos ? "client->server" : "server->client", newkeys-> enc.name, authlen == 0 ? newkeys->mac.name : "<implicit>" , newkeys->comp.name); |
| 1266 | } |
| 1267 | need = dh_need = 0; |
| 1268 | for (mode = 0; mode < MODE_MAX; mode++) { |
| 1269 | newkeys = kex->newkeys[mode]; |
| 1270 | need = MAXIMUM(need, newkeys->enc.key_len)(((need) > (newkeys->enc.key_len)) ? (need) : (newkeys-> enc.key_len)); |
| 1271 | need = MAXIMUM(need, newkeys->enc.block_size)(((need) > (newkeys->enc.block_size)) ? (need) : (newkeys ->enc.block_size)); |
| 1272 | need = MAXIMUM(need, newkeys->enc.iv_len)(((need) > (newkeys->enc.iv_len)) ? (need) : (newkeys-> enc.iv_len)); |
| 1273 | need = MAXIMUM(need, newkeys->mac.key_len)(((need) > (newkeys->mac.key_len)) ? (need) : (newkeys-> mac.key_len)); |
| 1274 | dh_need = MAXIMUM(dh_need, cipher_seclen(newkeys->enc.cipher))(((dh_need) > (cipher_seclen(newkeys->enc.cipher))) ? ( dh_need) : (cipher_seclen(newkeys->enc.cipher))); |
| 1275 | dh_need = MAXIMUM(dh_need, newkeys->enc.block_size)(((dh_need) > (newkeys->enc.block_size)) ? (dh_need) : ( newkeys->enc.block_size)); |
| 1276 | dh_need = MAXIMUM(dh_need, newkeys->enc.iv_len)(((dh_need) > (newkeys->enc.iv_len)) ? (dh_need) : (newkeys ->enc.iv_len)); |
| 1277 | dh_need = MAXIMUM(dh_need, newkeys->mac.key_len)(((dh_need) > (newkeys->mac.key_len)) ? (dh_need) : (newkeys ->mac.key_len)); |
| 1278 | } |
| 1279 | /* XXX need runden? */ |
| 1280 | kex->we_need = need; |
| 1281 | kex->dh_need = dh_need; |
| 1282 | |
| 1283 | /* ignore the next message if the proposals do not match */ |
| 1284 | if (first_kex_follows && !proposals_match(my, peer)) |
| 1285 | ssh->dispatch_skip_packets = 1; |
| 1286 | r = 0; |
| 1287 | out: |
| 1288 | kex_prop_free(my); |
| 1289 | kex_prop_free(peer); |
| 1290 | return r; |
| 1291 | } |
| 1292 | |
| 1293 | static int |
| 1294 | derive_key(struct ssh *ssh, int id, u_int need, u_char *hash, u_int hashlen, |
| 1295 | const struct sshbuf *shared_secret, u_char **keyp) |
| 1296 | { |
| 1297 | struct kex *kex = ssh->kex; |
| 1298 | struct ssh_digest_ctx *hashctx = NULL((void *)0); |
| 1299 | char c = id; |
| 1300 | u_int have; |
| 1301 | size_t mdsz; |
| 1302 | u_char *digest; |
| 1303 | int r; |
| 1304 | |
| 1305 | if ((mdsz = ssh_digest_bytes(kex->hash_alg)) == 0) |
| 1306 | return SSH_ERR_INVALID_ARGUMENT-10; |
| 1307 | if ((digest = calloc(1, ROUNDUP(need, mdsz)((((need)+((mdsz)-1))/(mdsz))*(mdsz)))) == NULL((void *)0)) { |
| 1308 | r = SSH_ERR_ALLOC_FAIL-2; |
| 1309 | goto out; |
| 1310 | } |
| 1311 | |
| 1312 | /* K1 = HASH(K || H || "A" || session_id) */ |
| 1313 | if ((hashctx = ssh_digest_start(kex->hash_alg)) == NULL((void *)0) || |
| 1314 | ssh_digest_update_buffer(hashctx, shared_secret) != 0 || |
| 1315 | ssh_digest_update(hashctx, hash, hashlen) != 0 || |
| 1316 | ssh_digest_update(hashctx, &c, 1) != 0 || |
| 1317 | ssh_digest_update_buffer(hashctx, kex->session_id) != 0 || |
| 1318 | ssh_digest_final(hashctx, digest, mdsz) != 0) { |
| 1319 | r = SSH_ERR_LIBCRYPTO_ERROR-22; |
| 1320 | error_f("KEX hash failed")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1320, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "KEX hash failed"); |
| 1321 | goto out; |
| 1322 | } |
| 1323 | ssh_digest_free(hashctx); |
| 1324 | hashctx = NULL((void *)0); |
| 1325 | |
| 1326 | /* |
| 1327 | * expand key: |
| 1328 | * Kn = HASH(K || H || K1 || K2 || ... || Kn-1) |
| 1329 | * Key = K1 || K2 || ... || Kn |
| 1330 | */ |
| 1331 | for (have = mdsz; need > have; have += mdsz) { |
| 1332 | if ((hashctx = ssh_digest_start(kex->hash_alg)) == NULL((void *)0) || |
| 1333 | ssh_digest_update_buffer(hashctx, shared_secret) != 0 || |
| 1334 | ssh_digest_update(hashctx, hash, hashlen) != 0 || |
| 1335 | ssh_digest_update(hashctx, digest, have) != 0 || |
| 1336 | ssh_digest_final(hashctx, digest + have, mdsz) != 0) { |
| 1337 | error_f("KDF failed")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1337, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "KDF failed"); |
| 1338 | r = SSH_ERR_LIBCRYPTO_ERROR-22; |
| 1339 | goto out; |
| 1340 | } |
| 1341 | ssh_digest_free(hashctx); |
| 1342 | hashctx = NULL((void *)0); |
| 1343 | } |
| 1344 | #ifdef DEBUG_KEX |
| 1345 | fprintf(stderr(&__sF[2]), "key '%c'== ", c); |
| 1346 | dump_digest("key", digest, need); |
| 1347 | #endif |
| 1348 | *keyp = digest; |
| 1349 | digest = NULL((void *)0); |
| 1350 | r = 0; |
| 1351 | out: |
| 1352 | free(digest); |
| 1353 | ssh_digest_free(hashctx); |
| 1354 | return r; |
| 1355 | } |
| 1356 | |
| 1357 | #define NKEYS6 6 |
| 1358 | int |
| 1359 | kex_derive_keys(struct ssh *ssh, u_char *hash, u_int hashlen, |
| 1360 | const struct sshbuf *shared_secret) |
| 1361 | { |
| 1362 | struct kex *kex = ssh->kex; |
| 1363 | u_char *keys[NKEYS6]; |
| 1364 | u_int i, j, mode, ctos; |
| 1365 | int r; |
| 1366 | |
| 1367 | /* save initial hash as session id */ |
| 1368 | if ((kex->flags & KEX_INITIAL0x0002) != 0) { |
| 1369 | if (sshbuf_len(kex->session_id) != 0) { |
| 1370 | error_f("already have session ID at kex")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1370, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "already have session ID at kex" ); |
| 1371 | return SSH_ERR_INTERNAL_ERROR-1; |
| 1372 | } |
| 1373 | if ((r = sshbuf_put(kex->session_id, hash, hashlen)) != 0) |
| 1374 | return r; |
| 1375 | } else if (sshbuf_len(kex->session_id) == 0) { |
| 1376 | error_f("no session ID in rekex")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1376, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "no session ID in rekex"); |
| 1377 | return SSH_ERR_INTERNAL_ERROR-1; |
| 1378 | } |
| 1379 | for (i = 0; i < NKEYS6; i++) { |
| 1380 | if ((r = derive_key(ssh, 'A'+i, kex->we_need, hash, hashlen, |
| 1381 | shared_secret, &keys[i])) != 0) { |
| 1382 | for (j = 0; j < i; j++) |
| 1383 | free(keys[j]); |
| 1384 | return r; |
| 1385 | } |
| 1386 | } |
| 1387 | for (mode = 0; mode < MODE_MAX; mode++) { |
| 1388 | ctos = (!kex->server && mode == MODE_OUT) || |
| 1389 | (kex->server && mode == MODE_IN); |
| 1390 | kex->newkeys[mode]->enc.iv = keys[ctos ? 0 : 1]; |
| 1391 | kex->newkeys[mode]->enc.key = keys[ctos ? 2 : 3]; |
| 1392 | kex->newkeys[mode]->mac.key = keys[ctos ? 4 : 5]; |
| 1393 | } |
| 1394 | return 0; |
| 1395 | } |
| 1396 | |
| 1397 | int |
| 1398 | kex_load_hostkey(struct ssh *ssh, struct sshkey **prvp, struct sshkey **pubp) |
| 1399 | { |
| 1400 | struct kex *kex = ssh->kex; |
| 1401 | |
| 1402 | *pubp = NULL((void *)0); |
| 1403 | *prvp = NULL((void *)0); |
| 1404 | if (kex->load_host_public_key == NULL((void *)0) || |
| 1405 | kex->load_host_private_key == NULL((void *)0)) { |
| 1406 | error_f("missing hostkey loader")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1406, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "missing hostkey loader"); |
| 1407 | return SSH_ERR_INVALID_ARGUMENT-10; |
| 1408 | } |
| 1409 | *pubp = kex->load_host_public_key(kex->hostkey_type, |
| 1410 | kex->hostkey_nid, ssh); |
| 1411 | *prvp = kex->load_host_private_key(kex->hostkey_type, |
| 1412 | kex->hostkey_nid, ssh); |
| 1413 | if (*pubp == NULL((void *)0)) |
| 1414 | return SSH_ERR_NO_HOSTKEY_LOADED-36; |
| 1415 | return 0; |
| 1416 | } |
| 1417 | |
| 1418 | int |
| 1419 | kex_verify_host_key(struct ssh *ssh, struct sshkey *server_host_key) |
| 1420 | { |
| 1421 | struct kex *kex = ssh->kex; |
| 1422 | |
| 1423 | if (kex->verify_host_key == NULL((void *)0)) { |
| 1424 | error_f("missing hostkey verifier")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1424, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "missing hostkey verifier" ); |
| 1425 | return SSH_ERR_INVALID_ARGUMENT-10; |
| 1426 | } |
| 1427 | if (server_host_key->type != kex->hostkey_type || |
| 1428 | (kex->hostkey_type == KEY_ECDSA && |
| 1429 | server_host_key->ecdsa_nid != kex->hostkey_nid)) |
| 1430 | return SSH_ERR_KEY_TYPE_MISMATCH-13; |
| 1431 | if (kex->verify_host_key(server_host_key, ssh) == -1) |
| 1432 | return SSH_ERR_SIGNATURE_INVALID-21; |
| 1433 | return 0; |
| 1434 | } |
| 1435 | |
| 1436 | #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH) |
| 1437 | void |
| 1438 | dump_digest(const char *msg, const u_char *digest, int len) |
| 1439 | { |
| 1440 | fprintf(stderr(&__sF[2]), "%s\n", msg); |
| 1441 | sshbuf_dump_data(digest, len, stderr(&__sF[2])); |
| 1442 | } |
| 1443 | #endif |
| 1444 | |
| 1445 | /* |
| 1446 | * Send a plaintext error message to the peer, suffixed by \r\n. |
| 1447 | * Only used during banner exchange, and there only for the server. |
| 1448 | */ |
| 1449 | static void |
| 1450 | send_error(struct ssh *ssh, char *msg) |
| 1451 | { |
| 1452 | char *crnl = "\r\n"; |
| 1453 | |
| 1454 | if (!ssh->kex->server) |
| 1455 | return; |
| 1456 | |
| 1457 | if (atomicio(vwrite(ssize_t (*)(int, void *, size_t))write, ssh_packet_get_connection_out(ssh), |
| 1458 | msg, strlen(msg)) != strlen(msg) || |
| 1459 | atomicio(vwrite(ssize_t (*)(int, void *, size_t))write, ssh_packet_get_connection_out(ssh), |
| 1460 | crnl, strlen(crnl)) != strlen(crnl)) |
| 1461 | error_f("write: %.100s", strerror(errno))sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1461, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "write: %.100s", strerror( (*__errno()))); |
| 1462 | } |
| 1463 | |
| 1464 | /* |
| 1465 | * Sends our identification string and waits for the peer's. Will block for |
| 1466 | * up to timeout_ms (or indefinitely if timeout_ms <= 0). |
| 1467 | * Returns on 0 success or a ssherr.h code on failure. |
| 1468 | */ |
| 1469 | int |
| 1470 | kex_exchange_identification(struct ssh *ssh, int timeout_ms, |
| 1471 | const char *version_addendum) |
| 1472 | { |
| 1473 | int remote_major, remote_minor, mismatch, oerrno = 0; |
| 1474 | size_t len, n; |
| 1475 | int r, expect_nl; |
| 1476 | u_char c; |
| 1477 | struct sshbuf *our_version = ssh->kex->server ? |
| 1478 | ssh->kex->server_version : ssh->kex->client_version; |
| 1479 | struct sshbuf *peer_version = ssh->kex->server ? |
| 1480 | ssh->kex->client_version : ssh->kex->server_version; |
| 1481 | char *our_version_string = NULL((void *)0), *peer_version_string = NULL((void *)0); |
| 1482 | char *cp, *remote_version = NULL((void *)0); |
| 1483 | |
| 1484 | /* Prepare and send our banner */ |
| 1485 | sshbuf_reset(our_version); |
| 1486 | if (version_addendum != NULL((void *)0) && *version_addendum == '\0') |
| 1487 | version_addendum = NULL((void *)0); |
| 1488 | if ((r = sshbuf_putf(our_version, "SSH-%d.%d-%s%s%s\r\n", |
| 1489 | PROTOCOL_MAJOR_22, PROTOCOL_MINOR_20, SSH_VERSION"OpenSSH_9.6", |
| 1490 | version_addendum == NULL((void *)0) ? "" : " ", |
| 1491 | version_addendum == NULL((void *)0) ? "" : version_addendum)) != 0) { |
| 1492 | oerrno = errno(*__errno()); |
| 1493 | error_fr(r, "sshbuf_putf")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1493, 1 , SYSLOG_LEVEL_ERROR, ssh_err(r), "sshbuf_putf"); |
| 1494 | goto out; |
| 1495 | } |
| 1496 | |
| 1497 | if (atomicio(vwrite(ssize_t (*)(int, void *, size_t))write, ssh_packet_get_connection_out(ssh), |
| 1498 | sshbuf_mutable_ptr(our_version), |
| 1499 | sshbuf_len(our_version)) != sshbuf_len(our_version)) { |
| 1500 | oerrno = errno(*__errno()); |
| 1501 | debug_f("write: %.100s", strerror(errno))sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1501, 1 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "write: %.100s", strerror ((*__errno()))); |
| 1502 | r = SSH_ERR_SYSTEM_ERROR-24; |
| 1503 | goto out; |
| 1504 | } |
| 1505 | if ((r = sshbuf_consume_end(our_version, 2)) != 0) { /* trim \r\n */ |
| 1506 | oerrno = errno(*__errno()); |
| 1507 | error_fr(r, "sshbuf_consume_end")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1507, 1 , SYSLOG_LEVEL_ERROR, ssh_err(r), "sshbuf_consume_end"); |
| 1508 | goto out; |
| 1509 | } |
| 1510 | our_version_string = sshbuf_dup_string(our_version); |
| 1511 | if (our_version_string == NULL((void *)0)) { |
| 1512 | error_f("sshbuf_dup_string failed")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1512, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "sshbuf_dup_string failed" ); |
| 1513 | r = SSH_ERR_ALLOC_FAIL-2; |
| 1514 | goto out; |
| 1515 | } |
| 1516 | debug("Local version string %.100s", our_version_string)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1516, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "Local version string %.100s" , our_version_string); |
| 1517 | |
| 1518 | /* Read other side's version identification. */ |
| 1519 | for (n = 0; ; n++) { |
| 1520 | if (n >= SSH_MAX_PRE_BANNER_LINES1024) { |
| 1521 | send_error(ssh, "No SSH identification string " |
| 1522 | "received."); |
| 1523 | error_f("No SSH version received in first %u lines "sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1524, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "No SSH version received in first %u lines " "from server", 1024) |
| 1524 | "from server", SSH_MAX_PRE_BANNER_LINES)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1524, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "No SSH version received in first %u lines " "from server", 1024); |
| 1525 | r = SSH_ERR_INVALID_FORMAT-4; |
| 1526 | goto out; |
| 1527 | } |
| 1528 | sshbuf_reset(peer_version); |
| 1529 | expect_nl = 0; |
| 1530 | for (;;) { |
| 1531 | if (timeout_ms > 0) { |
| 1532 | r = waitrfd(ssh_packet_get_connection_in(ssh), |
| 1533 | &timeout_ms, NULL((void *)0)); |
| 1534 | if (r == -1 && errno(*__errno()) == ETIMEDOUT60) { |
| 1535 | send_error(ssh, "Timed out waiting " |
| 1536 | "for SSH identification string."); |
| 1537 | error("Connection timed out during "sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1538, 0 , SYSLOG_LEVEL_ERROR, ((void *)0), "Connection timed out during " "banner exchange") |
| 1538 | "banner exchange")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1538, 0 , SYSLOG_LEVEL_ERROR, ((void *)0), "Connection timed out during " "banner exchange"); |
| 1539 | r = SSH_ERR_CONN_TIMEOUT-53; |
| 1540 | goto out; |
| 1541 | } else if (r == -1) { |
| 1542 | oerrno = errno(*__errno()); |
| 1543 | error_f("%s", strerror(errno))sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1543, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "%s", strerror((*__errno() ))); |
| 1544 | r = SSH_ERR_SYSTEM_ERROR-24; |
| 1545 | goto out; |
| 1546 | } |
| 1547 | } |
| 1548 | |
| 1549 | len = atomicio(read, ssh_packet_get_connection_in(ssh), |
| 1550 | &c, 1); |
| 1551 | if (len != 1 && errno(*__errno()) == EPIPE32) { |
| 1552 | verbose_f("Connection closed by remote host")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1552, 1 , SYSLOG_LEVEL_VERBOSE, ((void *)0), "Connection closed by remote host" ); |
| 1553 | r = SSH_ERR_CONN_CLOSED-52; |
| 1554 | goto out; |
| 1555 | } else if (len != 1) { |
| 1556 | oerrno = errno(*__errno()); |
| 1557 | error_f("read: %.100s", strerror(errno))sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1557, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "read: %.100s", strerror(( *__errno()))); |
| 1558 | r = SSH_ERR_SYSTEM_ERROR-24; |
| 1559 | goto out; |
| 1560 | } |
| 1561 | if (c == '\r') { |
| 1562 | expect_nl = 1; |
| 1563 | continue; |
| 1564 | } |
| 1565 | if (c == '\n') |
| 1566 | break; |
| 1567 | if (c == '\0' || expect_nl) { |
| 1568 | verbose_f("banner line contains invalid "sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1569, 1 , SYSLOG_LEVEL_VERBOSE, ((void *)0), "banner line contains invalid " "characters") |
| 1569 | "characters")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1569, 1 , SYSLOG_LEVEL_VERBOSE, ((void *)0), "banner line contains invalid " "characters"); |
| 1570 | goto invalid; |
| 1571 | } |
| 1572 | if ((r = sshbuf_put_u8(peer_version, c)) != 0) { |
| 1573 | oerrno = errno(*__errno()); |
| 1574 | error_fr(r, "sshbuf_put")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1574, 1 , SYSLOG_LEVEL_ERROR, ssh_err(r), "sshbuf_put"); |
| 1575 | goto out; |
| 1576 | } |
| 1577 | if (sshbuf_len(peer_version) > SSH_MAX_BANNER_LEN8192) { |
| 1578 | verbose_f("banner line too long")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1578, 1 , SYSLOG_LEVEL_VERBOSE, ((void *)0), "banner line too long"); |
| 1579 | goto invalid; |
| 1580 | } |
| 1581 | } |
| 1582 | /* Is this an actual protocol banner? */ |
| 1583 | if (sshbuf_len(peer_version) > 4 && |
| 1584 | memcmp(sshbuf_ptr(peer_version), "SSH-", 4) == 0) |
| 1585 | break; |
| 1586 | /* If not, then just log the line and continue */ |
| 1587 | if ((cp = sshbuf_dup_string(peer_version)) == NULL((void *)0)) { |
| 1588 | error_f("sshbuf_dup_string failed")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1588, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "sshbuf_dup_string failed" ); |
| 1589 | r = SSH_ERR_ALLOC_FAIL-2; |
| 1590 | goto out; |
| 1591 | } |
| 1592 | /* Do not accept lines before the SSH ident from a client */ |
| 1593 | if (ssh->kex->server) { |
| 1594 | verbose_f("client sent invalid protocol identifier "sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1595, 1 , SYSLOG_LEVEL_VERBOSE, ((void *)0), "client sent invalid protocol identifier " "\"%.256s\"", cp) |
| 1595 | "\"%.256s\"", cp)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1595, 1 , SYSLOG_LEVEL_VERBOSE, ((void *)0), "client sent invalid protocol identifier " "\"%.256s\"", cp); |
| 1596 | free(cp); |
| 1597 | goto invalid; |
| 1598 | } |
| 1599 | debug_f("banner line %zu: %s", n, cp)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1599, 1 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "banner line %zu: %s", n, cp); |
| 1600 | free(cp); |
| 1601 | } |
| 1602 | peer_version_string = sshbuf_dup_string(peer_version); |
| 1603 | if (peer_version_string == NULL((void *)0)) |
| 1604 | fatal_f("sshbuf_dup_string failed")sshfatal("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1604, 1, SYSLOG_LEVEL_FATAL, ((void *)0), "sshbuf_dup_string failed" ); |
| 1605 | /* XXX must be same size for sscanf */ |
| 1606 | if ((remote_version = calloc(1, sshbuf_len(peer_version))) == NULL((void *)0)) { |
| 1607 | error_f("calloc failed")sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1607, 1 , SYSLOG_LEVEL_ERROR, ((void *)0), "calloc failed"); |
| 1608 | r = SSH_ERR_ALLOC_FAIL-2; |
| 1609 | goto out; |
| 1610 | } |
| 1611 | |
| 1612 | /* |
| 1613 | * Check that the versions match. In future this might accept |
| 1614 | * several versions and set appropriate flags to handle them. |
| 1615 | */ |
| 1616 | if (sscanf(peer_version_string, "SSH-%d.%d-%[^\n]\n", |
| 1617 | &remote_major, &remote_minor, remote_version) != 3) { |
| 1618 | error("Bad remote protocol version identification: '%.100s'",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1619, 0 , SYSLOG_LEVEL_ERROR, ((void *)0), "Bad remote protocol version identification: '%.100s'" , peer_version_string) |
| 1619 | peer_version_string)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1619, 0 , SYSLOG_LEVEL_ERROR, ((void *)0), "Bad remote protocol version identification: '%.100s'" , peer_version_string); |
| 1620 | invalid: |
| 1621 | send_error(ssh, "Invalid SSH identification string."); |
| 1622 | r = SSH_ERR_INVALID_FORMAT-4; |
| 1623 | goto out; |
| 1624 | } |
| 1625 | debug("Remote protocol version %d.%d, remote software version %.100s",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1626, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "Remote protocol version %d.%d, remote software version %.100s" , remote_major, remote_minor, remote_version) |
| 1626 | remote_major, remote_minor, remote_version)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1626, 0 , SYSLOG_LEVEL_DEBUG1, ((void *)0), "Remote protocol version %d.%d, remote software version %.100s" , remote_major, remote_minor, remote_version); |
| 1627 | compat_banner(ssh, remote_version); |
| 1628 | |
| 1629 | mismatch = 0; |
| 1630 | switch (remote_major) { |
| 1631 | case 2: |
| 1632 | break; |
| 1633 | case 1: |
| 1634 | if (remote_minor != 99) |
| 1635 | mismatch = 1; |
| 1636 | break; |
| 1637 | default: |
| 1638 | mismatch = 1; |
| 1639 | break; |
| 1640 | } |
| 1641 | if (mismatch) { |
| 1642 | error("Protocol major versions differ: %d vs. %d",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1643, 0 , SYSLOG_LEVEL_ERROR, ((void *)0), "Protocol major versions differ: %d vs. %d" , 2, remote_major) |
| 1643 | PROTOCOL_MAJOR_2, remote_major)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1643, 0 , SYSLOG_LEVEL_ERROR, ((void *)0), "Protocol major versions differ: %d vs. %d" , 2, remote_major); |
| 1644 | send_error(ssh, "Protocol major versions differ."); |
| 1645 | r = SSH_ERR_NO_PROTOCOL_VERSION-38; |
| 1646 | goto out; |
| 1647 | } |
| 1648 | |
| 1649 | if (ssh->kex->server && (ssh->compat & SSH_BUG_PROBE0x00400000) != 0) { |
| 1650 | logit("probed from %s port %d with %s. Don't panic.",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1652, 0 , SYSLOG_LEVEL_INFO, ((void *)0), "probed from %s port %d with %s. Don't panic." , ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), peer_version_string ) |
| 1651 | ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1652, 0 , SYSLOG_LEVEL_INFO, ((void *)0), "probed from %s port %d with %s. Don't panic." , ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), peer_version_string ) |
| 1652 | peer_version_string)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1652, 0 , SYSLOG_LEVEL_INFO, ((void *)0), "probed from %s port %d with %s. Don't panic." , ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), peer_version_string ); |
| 1653 | r = SSH_ERR_CONN_CLOSED-52; /* XXX */ |
| 1654 | goto out; |
| 1655 | } |
| 1656 | if (ssh->kex->server && (ssh->compat & SSH_BUG_SCANNER0x00000800) != 0) { |
| 1657 | logit("scanned from %s port %d with %s. Don't panic.",sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1659, 0 , SYSLOG_LEVEL_INFO, ((void *)0), "scanned from %s port %d with %s. Don't panic." , ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), peer_version_string ) |
| 1658 | ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1659, 0 , SYSLOG_LEVEL_INFO, ((void *)0), "scanned from %s port %d with %s. Don't panic." , ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), peer_version_string ) |
| 1659 | peer_version_string)sshlog("/usr/src/usr.bin/ssh/ssh/../kex.c", __func__, 1659, 0 , SYSLOG_LEVEL_INFO, ((void *)0), "scanned from %s port %d with %s. Don't panic." , ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), peer_version_string ); |
| 1660 | r = SSH_ERR_CONN_CLOSED-52; /* XXX */ |
| 1661 | goto out; |
| 1662 | } |
| 1663 | /* success */ |
| 1664 | r = 0; |
| 1665 | out: |
| 1666 | free(our_version_string); |
| 1667 | free(peer_version_string); |
| 1668 | free(remote_version); |
| 1669 | if (r == SSH_ERR_SYSTEM_ERROR-24) |
| 1670 | errno(*__errno()) = oerrno; |
| 1671 | return r; |
| 1672 | } |
| 1673 |