Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2002 Niels Provos <provos@citi.umich.edu> |
| 3 | * Copyright 2002 Markus Friedl <markus@openbsd.org> |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 16 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 17 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 18 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 19 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 20 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 21 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 22 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 23 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 24 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 25 | */ |
| 26 | |
| 27 | #include "includes.h" |
| 28 | RCSID("$OpenBSD: monitor.c,v 1.6 2002/03/21 18:38:33 stevesk Exp $"); |
| 29 | |
| 30 | #include <openssl/dh.h> |
| 31 | |
| 32 | #ifdef SKEY |
| 33 | #include <skey.h> |
| 34 | #endif |
| 35 | |
| 36 | #include "ssh.h" |
| 37 | #include "auth.h" |
| 38 | #include "kex.h" |
| 39 | #include "dh.h" |
| 40 | #include "zlib.h" |
| 41 | #include "packet.h" |
| 42 | #include "auth-options.h" |
| 43 | #include "sshpty.h" |
| 44 | #include "channels.h" |
| 45 | #include "session.h" |
| 46 | #include "sshlogin.h" |
| 47 | #include "canohost.h" |
| 48 | #include "log.h" |
| 49 | #include "servconf.h" |
| 50 | #include "monitor.h" |
| 51 | #include "monitor_mm.h" |
| 52 | #include "monitor_wrap.h" |
| 53 | #include "monitor_fdpass.h" |
| 54 | #include "xmalloc.h" |
| 55 | #include "misc.h" |
| 56 | #include "buffer.h" |
| 57 | #include "bufaux.h" |
| 58 | #include "compat.h" |
| 59 | #include "ssh2.h" |
| 60 | #include "mpaux.h" |
| 61 | |
| 62 | /* Imports */ |
| 63 | extern ServerOptions options; |
| 64 | extern u_int utmp_len; |
| 65 | extern Newkeys *current_keys[]; |
| 66 | extern z_stream incoming_stream; |
| 67 | extern z_stream outgoing_stream; |
| 68 | extern u_char session_id[]; |
| 69 | extern Buffer input, output; |
| 70 | extern Buffer auth_debug; |
| 71 | extern int auth_debug_init; |
| 72 | |
| 73 | /* State exported from the child */ |
| 74 | |
| 75 | struct { |
| 76 | z_stream incoming; |
| 77 | z_stream outgoing; |
| 78 | u_char *keyin; |
| 79 | u_int keyinlen; |
| 80 | u_char *keyout; |
| 81 | u_int keyoutlen; |
| 82 | u_char *ivin; |
| 83 | u_int ivinlen; |
| 84 | u_char *ivout; |
| 85 | u_int ivoutlen; |
| 86 | int ssh1cipher; |
| 87 | int ssh1protoflags; |
| 88 | u_char *input; |
| 89 | u_int ilen; |
| 90 | u_char *output; |
| 91 | u_int olen; |
| 92 | } child_state; |
| 93 | |
| 94 | /* Functions on the montior that answer unprivileged requests */ |
| 95 | |
| 96 | int mm_answer_moduli(int, Buffer *); |
| 97 | int mm_answer_sign(int, Buffer *); |
| 98 | int mm_answer_pwnamallow(int, Buffer *); |
| 99 | int mm_answer_authserv(int, Buffer *); |
| 100 | int mm_answer_authpassword(int, Buffer *); |
| 101 | int mm_answer_bsdauthquery(int, Buffer *); |
| 102 | int mm_answer_bsdauthrespond(int, Buffer *); |
| 103 | int mm_answer_skeyquery(int, Buffer *); |
| 104 | int mm_answer_skeyrespond(int, Buffer *); |
| 105 | int mm_answer_keyallowed(int, Buffer *); |
| 106 | int mm_answer_keyverify(int, Buffer *); |
| 107 | int mm_answer_pty(int, Buffer *); |
| 108 | int mm_answer_pty_cleanup(int, Buffer *); |
| 109 | int mm_answer_term(int, Buffer *); |
| 110 | int mm_answer_rsa_keyallowed(int, Buffer *); |
| 111 | int mm_answer_rsa_challenge(int, Buffer *); |
| 112 | int mm_answer_rsa_response(int, Buffer *); |
| 113 | int mm_answer_sesskey(int, Buffer *); |
| 114 | int mm_answer_sessid(int, Buffer *); |
| 115 | |
| 116 | static Authctxt *authctxt; |
| 117 | static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ |
| 118 | |
| 119 | /* local state for key verify */ |
| 120 | static u_char *key_blob = NULL; |
| 121 | static u_int key_bloblen = 0; |
| 122 | static int key_blobtype = MM_NOKEY; |
| 123 | static u_char *hostbased_cuser = NULL; |
| 124 | static u_char *hostbased_chost = NULL; |
| 125 | static char *auth_method = "unknown"; |
| 126 | |
| 127 | struct mon_table { |
| 128 | enum monitor_reqtype type; |
| 129 | int flags; |
| 130 | int (*f)(int, Buffer *); |
| 131 | }; |
| 132 | |
| 133 | #define MON_ISAUTH 0x0004 /* Required for Authentication */ |
| 134 | #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ |
| 135 | #define MON_ONCE 0x0010 /* Disable after calling */ |
| 136 | |
| 137 | #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) |
| 138 | |
| 139 | #define MON_PERMIT 0x1000 /* Request is permitted */ |
| 140 | |
| 141 | struct mon_table mon_dispatch_proto20[] = { |
| 142 | {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, |
| 143 | {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, |
| 144 | {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, |
| 145 | {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, |
| 146 | {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, |
| 147 | #ifdef BSD_AUTH |
| 148 | {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, |
| 149 | {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, |
| 150 | #endif |
| 151 | #ifdef SKEY |
| 152 | {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, |
| 153 | {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, |
| 154 | #endif |
| 155 | {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, |
| 156 | {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, |
| 157 | {0, 0, NULL} |
| 158 | }; |
| 159 | |
| 160 | struct mon_table mon_dispatch_postauth20[] = { |
| 161 | {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, |
| 162 | {MONITOR_REQ_SIGN, 0, mm_answer_sign}, |
| 163 | {MONITOR_REQ_PTY, 0, mm_answer_pty}, |
| 164 | {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, |
| 165 | {MONITOR_REQ_TERM, 0, mm_answer_term}, |
| 166 | {0, 0, NULL} |
| 167 | }; |
| 168 | |
| 169 | struct mon_table mon_dispatch_proto15[] = { |
| 170 | {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, |
| 171 | {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, |
| 172 | {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, |
| 173 | {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, |
| 174 | {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed}, |
| 175 | {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, |
| 176 | {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, |
| 177 | {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, |
| 178 | #ifdef BSD_AUTH |
| 179 | {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, |
| 180 | {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, |
| 181 | #endif |
| 182 | #ifdef SKEY |
| 183 | {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, |
| 184 | {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, |
| 185 | #endif |
| 186 | {0, 0, NULL} |
| 187 | }; |
| 188 | |
| 189 | struct mon_table mon_dispatch_postauth15[] = { |
| 190 | {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, |
| 191 | {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, |
| 192 | {MONITOR_REQ_TERM, 0, mm_answer_term}, |
| 193 | {0, 0, NULL} |
| 194 | }; |
| 195 | |
| 196 | struct mon_table *mon_dispatch; |
| 197 | |
| 198 | /* Specifies if a certain message is allowed at the moment */ |
| 199 | |
| 200 | static void |
| 201 | monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) |
| 202 | { |
| 203 | while (ent->f != NULL) { |
| 204 | if (ent->type == type) { |
| 205 | ent->flags &= ~MON_PERMIT; |
| 206 | ent->flags |= permit ? MON_PERMIT : 0; |
| 207 | return; |
| 208 | } |
| 209 | ent++; |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | static void |
| 214 | monitor_permit_authentications(int permit) |
| 215 | { |
| 216 | struct mon_table *ent = mon_dispatch; |
| 217 | |
| 218 | while (ent->f != NULL) { |
| 219 | if (ent->flags & MON_AUTH) { |
| 220 | ent->flags &= ~MON_PERMIT; |
| 221 | ent->flags |= permit ? MON_PERMIT : 0; |
| 222 | } |
| 223 | ent++; |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | Authctxt * |
| 228 | monitor_child_preauth(struct monitor *monitor) |
| 229 | { |
| 230 | struct mon_table *ent; |
| 231 | int authenticated = 0; |
| 232 | |
| 233 | debug3("preauth child monitor started"); |
| 234 | |
| 235 | if (compat20) { |
| 236 | mon_dispatch = mon_dispatch_proto20; |
| 237 | |
| 238 | /* Permit requests for moduli and signatures */ |
| 239 | monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); |
| 240 | monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); |
| 241 | } else { |
| 242 | mon_dispatch = mon_dispatch_proto15; |
| 243 | |
| 244 | monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); |
| 245 | } |
| 246 | |
| 247 | authctxt = authctxt_new(); |
| 248 | |
| 249 | /* The first few requests do not require asynchronous access */ |
| 250 | while (!authenticated) { |
| 251 | authenticated = monitor_read(monitor, mon_dispatch, &ent); |
| 252 | if (authenticated) { |
| 253 | if (!(ent->flags & MON_AUTHDECIDE)) |
| 254 | fatal("%s: unexpected authentication from %d", |
| 255 | __FUNCTION__, ent->type); |
| 256 | if (authctxt->pw->pw_uid == 0 && |
| 257 | !auth_root_allowed(auth_method)) |
| 258 | authenticated = 0; |
| 259 | } |
| 260 | |
| 261 | if (ent->flags & MON_AUTHDECIDE) { |
| 262 | auth_log(authctxt, authenticated, auth_method, |
| 263 | compat20 ? " ssh2" : ""); |
| 264 | if (!authenticated) |
| 265 | authctxt->failures++; |
| 266 | } |
| 267 | } |
| 268 | |
| 269 | if (!authctxt->valid) |
| 270 | fatal("%s: authenticated invalid user", __FUNCTION__); |
| 271 | |
| 272 | debug("%s: %s has been authenticated by privileged process", |
| 273 | __FUNCTION__, authctxt->user); |
| 274 | |
| 275 | mm_get_keystate(monitor); |
| 276 | |
| 277 | return (authctxt); |
| 278 | } |
| 279 | |
| 280 | void |
| 281 | monitor_child_postauth(struct monitor *monitor) |
| 282 | { |
| 283 | if (compat20) { |
| 284 | mon_dispatch = mon_dispatch_postauth20; |
| 285 | |
| 286 | /* Permit requests for moduli and signatures */ |
| 287 | monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); |
| 288 | monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); |
| 289 | monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); |
| 290 | |
| 291 | } else { |
| 292 | mon_dispatch = mon_dispatch_postauth15; |
| 293 | monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); |
| 294 | } |
| 295 | if (!no_pty_flag) { |
| 296 | monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); |
| 297 | monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); |
| 298 | } |
| 299 | |
| 300 | for (;;) |
| 301 | monitor_read(monitor, mon_dispatch, NULL); |
| 302 | } |
| 303 | |
| 304 | void |
| 305 | monitor_sync(struct monitor *monitor) |
| 306 | { |
| 307 | /* The member allocation is not visible, so sync it */ |
| 308 | mm_share_sync(&monitor->m_zlib, &monitor->m_zback); |
| 309 | } |
| 310 | |
| 311 | int |
| 312 | monitor_read(struct monitor *monitor, struct mon_table *ent, |
| 313 | struct mon_table **pent) |
| 314 | { |
| 315 | Buffer m; |
| 316 | int ret; |
| 317 | u_char type; |
| 318 | |
| 319 | buffer_init(&m); |
| 320 | |
| 321 | mm_request_receive(monitor->m_sendfd, &m); |
| 322 | type = buffer_get_char(&m); |
| 323 | |
| 324 | debug3("%s: checking request %d", __FUNCTION__, type); |
| 325 | |
| 326 | while (ent->f != NULL) { |
| 327 | if (ent->type == type) |
| 328 | break; |
| 329 | ent++; |
| 330 | } |
| 331 | |
| 332 | if (ent->f != NULL) { |
| 333 | if (!(ent->flags & MON_PERMIT)) |
| 334 | fatal("%s: unpermitted request %d", __FUNCTION__, |
| 335 | type); |
| 336 | ret = (*ent->f)(monitor->m_sendfd, &m); |
| 337 | buffer_free(&m); |
| 338 | |
| 339 | /* The child may use this request only once, disable it */ |
| 340 | if (ent->flags & MON_ONCE) { |
| 341 | debug2("%s: %d used once, disabling now", __FUNCTION__, |
| 342 | type); |
| 343 | ent->flags &= ~MON_PERMIT; |
| 344 | } |
| 345 | |
| 346 | if (pent != NULL) |
| 347 | *pent = ent; |
| 348 | |
| 349 | return ret; |
| 350 | } |
| 351 | |
| 352 | fatal("%s: unsupported request: %d\n", __FUNCTION__, type); |
| 353 | |
| 354 | /* NOTREACHED */ |
| 355 | return (-1); |
| 356 | } |
| 357 | |
| 358 | /* allowed key state */ |
| 359 | static int |
| 360 | monitor_allowed_key(u_char *blob, u_int bloblen) |
| 361 | { |
| 362 | /* make sure key is allowed */ |
| 363 | if (key_blob == NULL || key_bloblen != bloblen || |
| 364 | memcmp(key_blob, blob, key_bloblen)) |
| 365 | return (0); |
| 366 | return (1); |
| 367 | } |
| 368 | |
| 369 | static void |
| 370 | monitor_reset_key_state(void) |
| 371 | { |
| 372 | /* reset state */ |
| 373 | if (key_blob != NULL) |
| 374 | xfree(key_blob); |
| 375 | if (hostbased_cuser != NULL) |
| 376 | xfree(hostbased_cuser); |
| 377 | if (hostbased_chost != NULL) |
| 378 | xfree(hostbased_chost); |
| 379 | key_blob = NULL; |
| 380 | key_bloblen = 0; |
| 381 | key_blobtype = MM_NOKEY; |
| 382 | hostbased_cuser = NULL; |
| 383 | hostbased_chost = NULL; |
| 384 | } |
| 385 | |
| 386 | int |
| 387 | mm_answer_moduli(int socket, Buffer *m) |
| 388 | { |
| 389 | DH *dh; |
| 390 | int min, want, max; |
| 391 | |
| 392 | min = buffer_get_int(m); |
| 393 | want = buffer_get_int(m); |
| 394 | max = buffer_get_int(m); |
| 395 | |
| 396 | debug3("%s: got parameters: %d %d %d", |
| 397 | __FUNCTION__, min, want, max); |
| 398 | /* We need to check here, too, in case the child got corrupted */ |
| 399 | if (max < min || want < min || max < want) |
| 400 | fatal("%s: bad parameters: %d %d %d", |
| 401 | __FUNCTION__, min, want, max); |
| 402 | |
| 403 | buffer_clear(m); |
| 404 | |
| 405 | dh = choose_dh(min, want, max); |
| 406 | if (dh == NULL) { |
| 407 | buffer_put_char(m, 0); |
| 408 | return (0); |
| 409 | } else { |
| 410 | /* Send first bignum */ |
| 411 | buffer_put_char(m, 1); |
| 412 | buffer_put_bignum2(m, dh->p); |
| 413 | buffer_put_bignum2(m, dh->g); |
| 414 | |
| 415 | DH_free(dh); |
| 416 | } |
| 417 | mm_request_send(socket, MONITOR_ANS_MODULI, m); |
| 418 | return (0); |
| 419 | } |
| 420 | |
| 421 | int |
| 422 | mm_answer_sign(int socket, Buffer *m) |
| 423 | { |
| 424 | Key *key; |
| 425 | u_char *p; |
| 426 | u_char *signature; |
| 427 | u_int siglen, datlen; |
| 428 | int keyid; |
| 429 | |
| 430 | debug3("%s", __FUNCTION__); |
| 431 | |
| 432 | keyid = buffer_get_int(m); |
| 433 | p = buffer_get_string(m, &datlen); |
| 434 | |
| 435 | if (datlen != 20) |
| 436 | fatal("%s: data length incorrect: %d", __FUNCTION__, datlen); |
| 437 | |
| 438 | if ((key = get_hostkey_by_index(keyid)) == NULL) |
| 439 | fatal("%s: no hostkey from index %d", __FUNCTION__, keyid); |
| 440 | if (key_sign(key, &signature, &siglen, p, datlen) < 0) |
| 441 | fatal("%s: key_sign failed", __FUNCTION__); |
| 442 | |
| 443 | debug3("%s: signature %p(%d)", __FUNCTION__, signature, siglen); |
| 444 | |
| 445 | buffer_clear(m); |
| 446 | buffer_put_string(m, signature, siglen); |
| 447 | |
| 448 | xfree(p); |
| 449 | xfree(signature); |
| 450 | |
| 451 | mm_request_send(socket, MONITOR_ANS_SIGN, m); |
| 452 | |
| 453 | /* Turn on permissions for getpwnam */ |
| 454 | monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); |
| 455 | |
| 456 | return (0); |
| 457 | } |
| 458 | |
| 459 | /* Retrieves the password entry and also checks if the user is permitted */ |
| 460 | |
| 461 | int |
| 462 | mm_answer_pwnamallow(int socket, Buffer *m) |
| 463 | { |
| 464 | char *login; |
| 465 | struct passwd *pwent; |
| 466 | int allowed = 0; |
| 467 | |
| 468 | debug3("%s", __FUNCTION__); |
| 469 | |
| 470 | if (authctxt->attempt++ != 0) |
| 471 | fatal("%s: multiple attempts for getpwnam", __FUNCTION__); |
| 472 | |
| 473 | login = buffer_get_string(m, NULL); |
| 474 | |
| 475 | pwent = getpwnamallow(login); |
| 476 | |
| 477 | authctxt->user = xstrdup(login); |
| 478 | setproctitle("%s [priv]", pwent ? login : "unknown"); |
| 479 | xfree(login); |
| 480 | |
| 481 | buffer_clear(m); |
| 482 | |
| 483 | if (pwent == NULL) { |
| 484 | buffer_put_char(m, 0); |
| 485 | goto out; |
| 486 | } |
| 487 | |
| 488 | allowed = 1; |
| 489 | authctxt->pw = pwent; |
| 490 | authctxt->valid = 1; |
| 491 | |
| 492 | buffer_put_char(m, 1); |
| 493 | buffer_put_string(m, pwent, sizeof(struct passwd)); |
| 494 | buffer_put_cstring(m, pwent->pw_name); |
| 495 | buffer_put_cstring(m, "*"); |
| 496 | buffer_put_cstring(m, pwent->pw_gecos); |
Kevin Steves | 7e14760 | 2002-03-22 18:07:17 +0000 | [diff] [blame] | 497 | #ifdef HAVE_PW_CLASS_IN_PASSWD |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 498 | buffer_put_cstring(m, pwent->pw_class); |
Kevin Steves | 7e14760 | 2002-03-22 18:07:17 +0000 | [diff] [blame] | 499 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 500 | buffer_put_cstring(m, pwent->pw_dir); |
| 501 | buffer_put_cstring(m, pwent->pw_shell); |
| 502 | |
| 503 | out: |
| 504 | debug3("%s: sending MONITOR_ANS_PWNAM: %d", __FUNCTION__, allowed); |
| 505 | mm_request_send(socket, MONITOR_ANS_PWNAM, m); |
| 506 | |
| 507 | /* For SSHv1 allow authentication now */ |
| 508 | if (!compat20) |
| 509 | monitor_permit_authentications(1); |
| 510 | else |
| 511 | /* Allow service/style information on the auth context */ |
| 512 | monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); |
| 513 | |
| 514 | |
| 515 | return (0); |
| 516 | } |
| 517 | |
| 518 | int |
| 519 | mm_answer_authserv(int socket, Buffer *m) |
| 520 | { |
| 521 | monitor_permit_authentications(1); |
| 522 | |
| 523 | authctxt->service = buffer_get_string(m, NULL); |
| 524 | authctxt->style = buffer_get_string(m, NULL); |
| 525 | debug3("%s: service=%s, style=%s", |
| 526 | __FUNCTION__, authctxt->service, authctxt->style); |
| 527 | |
| 528 | if (strlen(authctxt->style) == 0) { |
| 529 | xfree(authctxt->style); |
| 530 | authctxt->style = NULL; |
| 531 | } |
| 532 | |
| 533 | return (0); |
| 534 | } |
| 535 | |
| 536 | int |
| 537 | mm_answer_authpassword(int socket, Buffer *m) |
| 538 | { |
| 539 | static int call_count; |
| 540 | char *passwd; |
| 541 | int authenticated, plen; |
| 542 | |
| 543 | passwd = buffer_get_string(m, &plen); |
| 544 | /* Only authenticate if the context is valid */ |
| 545 | authenticated = authctxt->valid && auth_password(authctxt, passwd); |
| 546 | memset(passwd, 0, strlen(passwd)); |
| 547 | xfree(passwd); |
| 548 | |
| 549 | buffer_clear(m); |
| 550 | buffer_put_int(m, authenticated); |
| 551 | |
| 552 | debug3("%s: sending result %d", __FUNCTION__, authenticated); |
| 553 | mm_request_send(socket, MONITOR_ANS_AUTHPASSWORD, m); |
| 554 | |
| 555 | call_count++; |
| 556 | if (plen == 0 && call_count == 1) |
| 557 | auth_method = "none"; |
| 558 | else |
| 559 | auth_method = "password"; |
| 560 | |
| 561 | /* Causes monitor loop to terminate if authenticated */ |
| 562 | return (authenticated); |
| 563 | } |
| 564 | |
| 565 | #ifdef BSD_AUTH |
| 566 | int |
| 567 | mm_answer_bsdauthquery(int socket, Buffer *m) |
| 568 | { |
| 569 | char *name, *infotxt; |
| 570 | u_int numprompts; |
| 571 | u_int *echo_on; |
| 572 | char **prompts; |
| 573 | int res; |
| 574 | |
| 575 | res = bsdauth_query(authctxt, &name, &infotxt, &numprompts, |
| 576 | &prompts, &echo_on); |
| 577 | |
| 578 | buffer_clear(m); |
| 579 | buffer_put_int(m, res); |
| 580 | if (res != -1) |
| 581 | buffer_put_cstring(m, prompts[0]); |
| 582 | |
| 583 | debug3("%s: sending challenge res: %d", __FUNCTION__, res); |
| 584 | mm_request_send(socket, MONITOR_ANS_BSDAUTHQUERY, m); |
| 585 | |
| 586 | if (res != -1) { |
| 587 | xfree(name); |
| 588 | xfree(infotxt); |
| 589 | xfree(prompts); |
| 590 | xfree(echo_on); |
| 591 | } |
| 592 | |
| 593 | return (0); |
| 594 | } |
| 595 | |
| 596 | int |
| 597 | mm_answer_bsdauthrespond(int socket, Buffer *m) |
| 598 | { |
| 599 | char *response; |
| 600 | int authok; |
| 601 | |
| 602 | if (authctxt->as == 0) |
| 603 | fatal("%s: no bsd auth session", __FUNCTION__); |
| 604 | |
| 605 | response = buffer_get_string(m, NULL); |
| 606 | authok = auth_userresponse(authctxt->as, response, 0); |
| 607 | authctxt->as = NULL; |
| 608 | debug3("%s: <%s> = <%d>", __FUNCTION__, response, authok); |
| 609 | xfree(response); |
| 610 | |
| 611 | buffer_clear(m); |
| 612 | buffer_put_int(m, authok); |
| 613 | |
| 614 | debug3("%s: sending authenticated: %d", __FUNCTION__, authok); |
| 615 | mm_request_send(socket, MONITOR_ANS_BSDAUTHRESPOND, m); |
| 616 | |
| 617 | auth_method = "bsdauth"; |
| 618 | |
| 619 | return (authok != 0); |
| 620 | } |
| 621 | #endif |
| 622 | |
| 623 | #ifdef SKEY |
| 624 | int |
| 625 | mm_answer_skeyquery(int socket, Buffer *m) |
| 626 | { |
| 627 | struct skey skey; |
| 628 | char challenge[1024]; |
| 629 | int res; |
| 630 | |
| 631 | res = skeychallenge(&skey, authctxt->user, challenge); |
| 632 | |
| 633 | buffer_clear(m); |
| 634 | buffer_put_int(m, res); |
| 635 | if (res != -1) |
| 636 | buffer_put_cstring(m, challenge); |
| 637 | |
| 638 | debug3("%s: sending challenge res: %d", __FUNCTION__, res); |
| 639 | mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m); |
| 640 | |
| 641 | return (0); |
| 642 | } |
| 643 | |
| 644 | int |
| 645 | mm_answer_skeyrespond(int socket, Buffer *m) |
| 646 | { |
| 647 | char *response; |
| 648 | int authok; |
| 649 | |
| 650 | response = buffer_get_string(m, NULL); |
| 651 | |
| 652 | authok = (authctxt->valid && |
| 653 | skey_haskey(authctxt->pw->pw_name) == 0 && |
| 654 | skey_passcheck(authctxt->pw->pw_name, response) != -1); |
| 655 | |
| 656 | xfree(response); |
| 657 | |
| 658 | buffer_clear(m); |
| 659 | buffer_put_int(m, authok); |
| 660 | |
| 661 | debug3("%s: sending authenticated: %d", __FUNCTION__, authok); |
| 662 | mm_request_send(socket, MONITOR_ANS_SKEYRESPOND, m); |
| 663 | |
| 664 | auth_method = "skey"; |
| 665 | |
| 666 | return (authok != 0); |
| 667 | } |
| 668 | #endif |
| 669 | |
| 670 | static void |
| 671 | mm_append_debug(Buffer *m) |
| 672 | { |
| 673 | if (auth_debug_init && buffer_len(&auth_debug)) { |
| 674 | debug3("%s: Appending debug messages for child", __FUNCTION__); |
| 675 | buffer_append(m, buffer_ptr(&auth_debug), |
| 676 | buffer_len(&auth_debug)); |
| 677 | buffer_clear(&auth_debug); |
| 678 | } |
| 679 | } |
| 680 | |
| 681 | int |
| 682 | mm_answer_keyallowed(int socket, Buffer *m) |
| 683 | { |
| 684 | Key *key; |
| 685 | u_char *cuser, *chost, *blob; |
| 686 | u_int bloblen; |
| 687 | enum mm_keytype type = 0; |
| 688 | int allowed = 0; |
| 689 | |
| 690 | debug3("%s entering", __FUNCTION__); |
| 691 | |
| 692 | type = buffer_get_int(m); |
| 693 | cuser = buffer_get_string(m, NULL); |
| 694 | chost = buffer_get_string(m, NULL); |
| 695 | blob = buffer_get_string(m, &bloblen); |
| 696 | |
| 697 | key = key_from_blob(blob, bloblen); |
| 698 | |
| 699 | if ((compat20 && type == MM_RSAHOSTKEY) || |
| 700 | (!compat20 && type != MM_RSAHOSTKEY)) |
| 701 | fatal("%s: key type and protocol mismatch", __FUNCTION__); |
| 702 | |
| 703 | debug3("%s: key_from_blob: %p", __FUNCTION__, key); |
| 704 | |
| 705 | if (key != NULL && authctxt->pw != NULL) { |
| 706 | switch(type) { |
| 707 | case MM_USERKEY: |
| 708 | allowed = user_key_allowed(authctxt->pw, key); |
| 709 | break; |
| 710 | case MM_HOSTKEY: |
| 711 | allowed = hostbased_key_allowed(authctxt->pw, |
| 712 | cuser, chost, key); |
| 713 | break; |
| 714 | case MM_RSAHOSTKEY: |
| 715 | key->type = KEY_RSA1; /* XXX */ |
| 716 | allowed = auth_rhosts_rsa_key_allowed(authctxt->pw, |
| 717 | cuser, chost, key); |
| 718 | break; |
| 719 | default: |
| 720 | fatal("%s: unknown key type %d", __FUNCTION__, type); |
| 721 | break; |
| 722 | } |
| 723 | key_free(key); |
| 724 | } |
| 725 | |
| 726 | /* clear temporarily storage (used by verify) */ |
| 727 | monitor_reset_key_state(); |
| 728 | |
| 729 | if (allowed) { |
| 730 | /* Save temporarily for comparison in verify */ |
| 731 | key_blob = blob; |
| 732 | key_bloblen = bloblen; |
| 733 | key_blobtype = type; |
| 734 | hostbased_cuser = cuser; |
| 735 | hostbased_chost = chost; |
| 736 | } |
| 737 | |
| 738 | debug3("%s: key %p is %s", |
| 739 | __FUNCTION__, key, allowed ? "allowed" : "disallowed"); |
| 740 | |
| 741 | buffer_clear(m); |
| 742 | buffer_put_int(m, allowed); |
| 743 | |
| 744 | mm_append_debug(m); |
| 745 | |
| 746 | mm_request_send(socket, MONITOR_ANS_KEYALLOWED, m); |
| 747 | |
| 748 | if (type == MM_RSAHOSTKEY) |
| 749 | monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); |
| 750 | |
| 751 | return (0); |
| 752 | } |
| 753 | |
| 754 | static int |
| 755 | monitor_valid_userblob(u_char *data, u_int datalen) |
| 756 | { |
| 757 | Buffer b; |
| 758 | u_char *p; |
| 759 | u_int len; |
| 760 | int fail = 0; |
| 761 | int session_id2_len = 20 /*XXX should get from [net] */; |
| 762 | |
| 763 | buffer_init(&b); |
| 764 | buffer_append(&b, data, datalen); |
| 765 | |
| 766 | if (datafellows & SSH_OLD_SESSIONID) { |
| 767 | buffer_consume(&b, session_id2_len); |
| 768 | } else { |
| 769 | xfree(buffer_get_string(&b, &len)); |
| 770 | if (len != session_id2_len) |
| 771 | fail++; |
| 772 | } |
| 773 | if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) |
| 774 | fail++; |
| 775 | p = buffer_get_string(&b, NULL); |
| 776 | if (strcmp(authctxt->user, p) != 0) { |
| 777 | log("wrong user name passed to monitor: expected %s != %.100s", |
| 778 | authctxt->user, p); |
| 779 | fail++; |
| 780 | } |
| 781 | xfree(p); |
| 782 | buffer_skip_string(&b); |
| 783 | if (datafellows & SSH_BUG_PKAUTH) { |
| 784 | if (!buffer_get_char(&b)) |
| 785 | fail++; |
| 786 | } else { |
| 787 | p = buffer_get_string(&b, NULL); |
| 788 | if (strcmp("publickey", p) != 0) |
| 789 | fail++; |
| 790 | xfree(p); |
| 791 | if (!buffer_get_char(&b)) |
| 792 | fail++; |
| 793 | buffer_skip_string(&b); |
| 794 | } |
| 795 | buffer_skip_string(&b); |
| 796 | if (buffer_len(&b) != 0) |
| 797 | fail++; |
| 798 | buffer_free(&b); |
| 799 | return (fail == 0); |
| 800 | } |
| 801 | |
| 802 | static int |
| 803 | monitor_valid_hostbasedblob(u_char *data, u_int datalen, u_char *cuser, |
| 804 | u_char *chost) |
| 805 | { |
| 806 | Buffer b; |
| 807 | u_char *p; |
| 808 | u_int len; |
| 809 | int fail = 0; |
| 810 | int session_id2_len = 20 /*XXX should get from [net] */; |
| 811 | |
| 812 | buffer_init(&b); |
| 813 | buffer_append(&b, data, datalen); |
| 814 | |
| 815 | xfree(buffer_get_string(&b, &len)); |
| 816 | if (len != session_id2_len) |
| 817 | fail++; |
| 818 | if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) |
| 819 | fail++; |
| 820 | p = buffer_get_string(&b, NULL); |
| 821 | if (strcmp(authctxt->user, p) != 0) { |
| 822 | log("wrong user name passed to monitor: expected %s != %.100s", |
| 823 | authctxt->user, p); |
| 824 | fail++; |
| 825 | } |
| 826 | xfree(p); |
| 827 | buffer_skip_string(&b); /* service */ |
| 828 | p = buffer_get_string(&b, NULL); |
| 829 | if (strcmp(p, "hostbased") != 0) |
| 830 | fail++; |
| 831 | xfree(p); |
| 832 | buffer_skip_string(&b); /* pkalg */ |
| 833 | buffer_skip_string(&b); /* pkblob */ |
| 834 | |
| 835 | /* verify client host, strip trailing dot if necessary */ |
| 836 | p = buffer_get_string(&b, NULL); |
| 837 | if (((len = strlen(p)) > 0) && p[len - 1] == '.') |
| 838 | p[len - 1] = '\0'; |
| 839 | if (strcmp(p, chost) != 0) |
| 840 | fail++; |
| 841 | xfree(p); |
| 842 | |
| 843 | /* verify client user */ |
| 844 | p = buffer_get_string(&b, NULL); |
| 845 | if (strcmp(p, cuser) != 0) |
| 846 | fail++; |
| 847 | xfree(p); |
| 848 | |
| 849 | if (buffer_len(&b) != 0) |
| 850 | fail++; |
| 851 | buffer_free(&b); |
| 852 | return (fail == 0); |
| 853 | } |
| 854 | |
| 855 | int |
| 856 | mm_answer_keyverify(int socket, Buffer *m) |
| 857 | { |
| 858 | Key *key; |
| 859 | u_char *signature, *data, *blob; |
| 860 | u_int signaturelen, datalen, bloblen; |
| 861 | int verified = 0; |
| 862 | int valid_data = 0; |
| 863 | |
| 864 | blob = buffer_get_string(m, &bloblen); |
| 865 | signature = buffer_get_string(m, &signaturelen); |
| 866 | data = buffer_get_string(m, &datalen); |
| 867 | |
| 868 | if (hostbased_cuser == NULL || hostbased_chost == NULL || |
| 869 | monitor_allowed_key(blob, bloblen) == NULL) |
| 870 | fatal("%s: bad key, not previously allowed", __FUNCTION__); |
| 871 | |
| 872 | key = key_from_blob(blob, bloblen); |
| 873 | if (key == NULL) |
| 874 | fatal("%s: bad public key blob", __FUNCTION__); |
| 875 | |
| 876 | switch (key_blobtype) { |
| 877 | case MM_USERKEY: |
| 878 | valid_data = monitor_valid_userblob(data, datalen); |
| 879 | break; |
| 880 | case MM_HOSTKEY: |
| 881 | valid_data = monitor_valid_hostbasedblob(data, datalen, |
| 882 | hostbased_cuser, hostbased_chost); |
| 883 | break; |
| 884 | default: |
| 885 | valid_data = 0; |
| 886 | break; |
| 887 | } |
| 888 | if (!valid_data) |
| 889 | fatal("%s: bad signature data blob", __FUNCTION__); |
| 890 | |
| 891 | verified = key_verify(key, signature, signaturelen, data, datalen); |
| 892 | debug3("%s: key %p signature %s", |
| 893 | __FUNCTION__, key, verified ? "verified" : "unverified"); |
| 894 | |
| 895 | key_free(key); |
| 896 | xfree(blob); |
| 897 | xfree(signature); |
| 898 | xfree(data); |
| 899 | |
| 900 | monitor_reset_key_state(); |
| 901 | |
| 902 | buffer_clear(m); |
| 903 | buffer_put_int(m, verified); |
| 904 | mm_request_send(socket, MONITOR_ANS_KEYVERIFY, m); |
| 905 | |
| 906 | auth_method = "publickey"; |
| 907 | |
| 908 | return (verified); |
| 909 | } |
| 910 | |
| 911 | static void |
| 912 | mm_record_login(Session *s, struct passwd *pw) |
| 913 | { |
| 914 | socklen_t fromlen; |
| 915 | struct sockaddr_storage from; |
| 916 | |
| 917 | /* |
| 918 | * Get IP address of client. If the connection is not a socket, let |
| 919 | * the address be 0.0.0.0. |
| 920 | */ |
| 921 | memset(&from, 0, sizeof(from)); |
| 922 | if (packet_connection_is_on_socket()) { |
| 923 | fromlen = sizeof(from); |
| 924 | if (getpeername(packet_get_connection_in(), |
| 925 | (struct sockaddr *) & from, &fromlen) < 0) { |
| 926 | debug("getpeername: %.100s", strerror(errno)); |
| 927 | fatal_cleanup(); |
| 928 | } |
| 929 | } |
| 930 | /* Record that there was a login on that tty from the remote host. */ |
| 931 | record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, |
| 932 | get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping), |
| 933 | (struct sockaddr *)&from); |
| 934 | } |
| 935 | |
| 936 | static void |
| 937 | mm_session_close(Session *s) |
| 938 | { |
| 939 | debug3("%s: session %d pid %d", __FUNCTION__, s->self, s->pid); |
| 940 | if (s->ttyfd != -1) { |
| 941 | debug3("%s: tty %s ptyfd %d", __FUNCTION__, s->tty, s->ptyfd); |
| 942 | fatal_remove_cleanup(session_pty_cleanup2, (void *)s); |
| 943 | session_pty_cleanup2(s); |
| 944 | } |
| 945 | s->used = 0; |
| 946 | } |
| 947 | |
| 948 | int |
| 949 | mm_answer_pty(int socket, Buffer *m) |
| 950 | { |
| 951 | extern struct monitor *monitor; |
| 952 | Session *s; |
| 953 | int res, fd0; |
| 954 | |
| 955 | debug3("%s entering", __FUNCTION__); |
| 956 | |
| 957 | buffer_clear(m); |
| 958 | s = session_new(); |
| 959 | if (s == NULL) |
| 960 | goto error; |
| 961 | s->authctxt = authctxt; |
| 962 | s->pw = authctxt->pw; |
| 963 | s->pid = monitor->m_pid; |
| 964 | res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); |
| 965 | if (res == 0) |
| 966 | goto error; |
| 967 | fatal_add_cleanup(session_pty_cleanup2, (void *)s); |
| 968 | pty_setowner(authctxt->pw, s->tty); |
| 969 | |
| 970 | buffer_put_int(m, 1); |
| 971 | buffer_put_cstring(m, s->tty); |
| 972 | mm_request_send(socket, MONITOR_ANS_PTY, m); |
| 973 | |
| 974 | mm_send_fd(socket, s->ptyfd); |
| 975 | mm_send_fd(socket, s->ttyfd); |
| 976 | |
| 977 | /* We need to trick ttyslot */ |
| 978 | if (dup2(s->ttyfd, 0) == -1) |
| 979 | fatal("%s: dup2", __FUNCTION__); |
| 980 | |
| 981 | mm_record_login(s, authctxt->pw); |
| 982 | |
| 983 | /* Now we can close the file descriptor again */ |
| 984 | close(0); |
| 985 | |
| 986 | /* make sure nothing uses fd 0 */ |
| 987 | if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) |
| 988 | fatal("%s: open(/dev/null): %s", __FUNCTION__, strerror(errno)); |
| 989 | if (fd0 != 0) |
| 990 | error("%s: fd0 %d != 0", __FUNCTION__, fd0); |
| 991 | |
| 992 | /* slave is not needed */ |
| 993 | close(s->ttyfd); |
| 994 | s->ttyfd = s->ptyfd; |
| 995 | /* no need to dup() because nobody closes ptyfd */ |
| 996 | s->ptymaster = s->ptyfd; |
| 997 | |
| 998 | debug3("%s: tty %s ptyfd %d", __FUNCTION__, s->tty, s->ttyfd); |
| 999 | |
| 1000 | return (0); |
| 1001 | |
| 1002 | error: |
| 1003 | if (s != NULL) |
| 1004 | mm_session_close(s); |
| 1005 | buffer_put_int(m, 0); |
| 1006 | mm_request_send(socket, MONITOR_ANS_PTY, m); |
| 1007 | return (0); |
| 1008 | } |
| 1009 | |
| 1010 | int |
| 1011 | mm_answer_pty_cleanup(int socket, Buffer *m) |
| 1012 | { |
| 1013 | Session *s; |
| 1014 | char *tty; |
| 1015 | |
| 1016 | debug3("%s entering", __FUNCTION__); |
| 1017 | |
| 1018 | tty = buffer_get_string(m, NULL); |
| 1019 | if ((s = session_by_tty(tty)) != NULL) |
| 1020 | mm_session_close(s); |
| 1021 | buffer_clear(m); |
| 1022 | xfree(tty); |
| 1023 | return (0); |
| 1024 | } |
| 1025 | |
| 1026 | int |
| 1027 | mm_answer_sesskey(int socket, Buffer *m) |
| 1028 | { |
| 1029 | BIGNUM *p; |
| 1030 | int rsafail; |
| 1031 | |
| 1032 | /* Turn off permissions */ |
| 1033 | monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); |
| 1034 | |
| 1035 | if ((p = BN_new()) == NULL) |
| 1036 | fatal("%s: BN_new", __FUNCTION__); |
| 1037 | |
| 1038 | buffer_get_bignum2(m, p); |
| 1039 | |
| 1040 | rsafail = ssh1_session_key(p); |
| 1041 | |
| 1042 | buffer_clear(m); |
| 1043 | buffer_put_int(m, rsafail); |
| 1044 | buffer_put_bignum2(m, p); |
| 1045 | |
| 1046 | BN_clear_free(p); |
| 1047 | |
| 1048 | mm_request_send(socket, MONITOR_ANS_SESSKEY, m); |
| 1049 | |
| 1050 | /* Turn on permissions for sessid passing */ |
| 1051 | monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); |
| 1052 | |
| 1053 | return (0); |
| 1054 | } |
| 1055 | |
| 1056 | int |
| 1057 | mm_answer_sessid(int socket, Buffer *m) |
| 1058 | { |
| 1059 | int i; |
| 1060 | |
| 1061 | debug3("%s entering", __FUNCTION__); |
| 1062 | |
| 1063 | if (buffer_len(m) != 16) |
| 1064 | fatal("%s: bad ssh1 session id", __FUNCTION__); |
| 1065 | for (i = 0; i < 16; i++) |
| 1066 | session_id[i] = buffer_get_char(m); |
| 1067 | |
| 1068 | /* Turn on permissions for getpwnam */ |
| 1069 | monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); |
| 1070 | |
| 1071 | return (0); |
| 1072 | } |
| 1073 | |
| 1074 | int |
| 1075 | mm_answer_rsa_keyallowed(int socket, Buffer *m) |
| 1076 | { |
| 1077 | BIGNUM *client_n; |
| 1078 | Key *key = NULL; |
| 1079 | u_char *blob = NULL; |
| 1080 | u_int blen = 0; |
| 1081 | int allowed = 0; |
| 1082 | |
| 1083 | debug3("%s entering", __FUNCTION__); |
| 1084 | |
| 1085 | if (authctxt->valid) { |
| 1086 | if ((client_n = BN_new()) == NULL) |
| 1087 | fatal("%s: BN_new", __FUNCTION__); |
| 1088 | buffer_get_bignum2(m, client_n); |
| 1089 | allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); |
| 1090 | BN_clear_free(client_n); |
| 1091 | } |
| 1092 | buffer_clear(m); |
| 1093 | buffer_put_int(m, allowed); |
| 1094 | |
| 1095 | /* clear temporarily storage (used by generate challenge) */ |
| 1096 | monitor_reset_key_state(); |
| 1097 | |
| 1098 | if (allowed && key != NULL) { |
| 1099 | key->type = KEY_RSA; /* cheat for key_to_blob */ |
| 1100 | if (key_to_blob(key, &blob, &blen) == 0) |
| 1101 | fatal("%s: key_to_blob failed", __FUNCTION__); |
| 1102 | buffer_put_string(m, blob, blen); |
| 1103 | |
| 1104 | /* Save temporarily for comparison in verify */ |
| 1105 | key_blob = blob; |
| 1106 | key_bloblen = blen; |
| 1107 | key_blobtype = MM_RSAUSERKEY; |
| 1108 | key_free(key); |
| 1109 | } |
| 1110 | |
| 1111 | mm_append_debug(m); |
| 1112 | |
| 1113 | mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m); |
| 1114 | |
| 1115 | monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); |
| 1116 | monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); |
| 1117 | return (0); |
| 1118 | } |
| 1119 | |
| 1120 | int |
| 1121 | mm_answer_rsa_challenge(int socket, Buffer *m) |
| 1122 | { |
| 1123 | Key *key = NULL; |
| 1124 | u_char *blob; |
| 1125 | u_int blen; |
| 1126 | |
| 1127 | debug3("%s entering", __FUNCTION__); |
| 1128 | |
| 1129 | if (!authctxt->valid) |
| 1130 | fatal("%s: authctxt not valid", __FUNCTION__); |
| 1131 | blob = buffer_get_string(m, &blen); |
| 1132 | if (!monitor_allowed_key(blob, blen)) |
| 1133 | fatal("%s: bad key, not previously allowed", __FUNCTION__); |
| 1134 | if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) |
| 1135 | fatal("%s: key type mismatch", __FUNCTION__); |
| 1136 | if ((key = key_from_blob(blob, blen)) == NULL) |
| 1137 | fatal("%s: received bad key", __FUNCTION__); |
| 1138 | |
| 1139 | if (ssh1_challenge) |
| 1140 | BN_clear_free(ssh1_challenge); |
| 1141 | ssh1_challenge = auth_rsa_generate_challenge(key); |
| 1142 | |
| 1143 | buffer_clear(m); |
| 1144 | buffer_put_bignum2(m, ssh1_challenge); |
| 1145 | |
| 1146 | debug3("%s sending reply", __FUNCTION__); |
| 1147 | mm_request_send(socket, MONITOR_ANS_RSACHALLENGE, m); |
| 1148 | |
| 1149 | monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); |
| 1150 | return (0); |
| 1151 | } |
| 1152 | |
| 1153 | int |
| 1154 | mm_answer_rsa_response(int socket, Buffer *m) |
| 1155 | { |
| 1156 | Key *key = NULL; |
| 1157 | u_char *blob, *response; |
| 1158 | u_int blen, len; |
| 1159 | int success; |
| 1160 | |
| 1161 | debug3("%s entering", __FUNCTION__); |
| 1162 | |
| 1163 | if (!authctxt->valid) |
| 1164 | fatal("%s: authctxt not valid", __FUNCTION__); |
| 1165 | if (ssh1_challenge == NULL) |
| 1166 | fatal("%s: no ssh1_challenge", __FUNCTION__); |
| 1167 | |
| 1168 | blob = buffer_get_string(m, &blen); |
| 1169 | if (!monitor_allowed_key(blob, blen)) |
| 1170 | fatal("%s: bad key, not previously allowed", __FUNCTION__); |
| 1171 | if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) |
| 1172 | fatal("%s: key type mismatch: %d", __FUNCTION__, key_blobtype); |
| 1173 | if ((key = key_from_blob(blob, blen)) == NULL) |
| 1174 | fatal("%s: received bad key", __FUNCTION__); |
| 1175 | response = buffer_get_string(m, &len); |
| 1176 | if (len != 16) |
| 1177 | fatal("%s: received bad response to challenge", __FUNCTION__); |
| 1178 | success = auth_rsa_verify_response(key, ssh1_challenge, response); |
| 1179 | |
| 1180 | key_free(key); |
| 1181 | xfree(response); |
| 1182 | |
| 1183 | auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; |
| 1184 | |
| 1185 | /* reset state */ |
| 1186 | BN_clear_free(ssh1_challenge); |
| 1187 | ssh1_challenge = NULL; |
| 1188 | monitor_reset_key_state(); |
| 1189 | |
| 1190 | buffer_clear(m); |
| 1191 | buffer_put_int(m, success); |
| 1192 | mm_request_send(socket, MONITOR_ANS_RSARESPONSE, m); |
| 1193 | |
| 1194 | return (success); |
| 1195 | } |
| 1196 | |
| 1197 | int |
| 1198 | mm_answer_term(int socket, Buffer *req) |
| 1199 | { |
| 1200 | extern struct monitor *monitor; |
| 1201 | int res, status; |
| 1202 | |
| 1203 | debug3("%s: tearing down sessions", __FUNCTION__); |
| 1204 | |
| 1205 | /* The child is terminating */ |
| 1206 | session_destroy_all(&mm_session_close); |
| 1207 | |
| 1208 | if (waitpid(monitor->m_pid, &status, 0) == -1) |
| 1209 | exit(1); |
| 1210 | |
| 1211 | res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; |
| 1212 | |
| 1213 | /* Terminate process */ |
| 1214 | exit (res); |
| 1215 | } |
| 1216 | |
| 1217 | void |
| 1218 | monitor_apply_keystate(struct monitor *monitor) |
| 1219 | { |
| 1220 | if (compat20) { |
| 1221 | set_newkeys(MODE_IN); |
| 1222 | set_newkeys(MODE_OUT); |
| 1223 | } else { |
| 1224 | u_char key[SSH_SESSION_KEY_LENGTH]; |
| 1225 | |
| 1226 | memset(key, 'a', sizeof(key)); |
| 1227 | packet_set_protocol_flags(child_state.ssh1protoflags); |
| 1228 | packet_set_encryption_key(key, SSH_SESSION_KEY_LENGTH, |
| 1229 | child_state.ssh1cipher); |
| 1230 | } |
| 1231 | |
| 1232 | packet_set_keycontext(MODE_OUT, child_state.keyout); |
| 1233 | xfree(child_state.keyout); |
| 1234 | packet_set_keycontext(MODE_IN, child_state.keyin); |
| 1235 | xfree(child_state.keyin); |
| 1236 | |
| 1237 | if (!compat20) { |
| 1238 | packet_set_iv(MODE_OUT, child_state.ivout); |
| 1239 | xfree(child_state.ivout); |
| 1240 | packet_set_iv(MODE_IN, child_state.ivin); |
| 1241 | xfree(child_state.ivin); |
| 1242 | } |
| 1243 | |
| 1244 | memcpy(&incoming_stream, &child_state.incoming, |
| 1245 | sizeof(incoming_stream)); |
| 1246 | memcpy(&outgoing_stream, &child_state.outgoing, |
| 1247 | sizeof(outgoing_stream)); |
| 1248 | |
| 1249 | /* Update with new address */ |
| 1250 | mm_init_compression(monitor->m_zlib); |
| 1251 | |
| 1252 | /* Network I/O buffers */ |
| 1253 | /* XXX inefficient for large buffers, need: buffer_init_from_string */ |
| 1254 | buffer_clear(&input); |
| 1255 | buffer_append(&input, child_state.input, child_state.ilen); |
| 1256 | memset(child_state.input, 0, child_state.ilen); |
| 1257 | xfree(child_state.input); |
| 1258 | |
| 1259 | buffer_clear(&output); |
| 1260 | buffer_append(&output, child_state.output, child_state.olen); |
| 1261 | memset(child_state.output, 0, child_state.olen); |
| 1262 | xfree(child_state.output); |
| 1263 | } |
| 1264 | |
| 1265 | static Kex * |
| 1266 | mm_get_kex(Buffer *m) |
| 1267 | { |
| 1268 | Kex *kex; |
| 1269 | void *blob; |
| 1270 | u_int bloblen; |
| 1271 | |
| 1272 | kex = xmalloc(sizeof(*kex)); |
| 1273 | memset(kex, 0, sizeof(*kex)); |
| 1274 | kex->session_id = buffer_get_string(m, &kex->session_id_len); |
| 1275 | kex->we_need = buffer_get_int(m); |
| 1276 | kex->server = 1; |
| 1277 | kex->hostkey_type = buffer_get_int(m); |
| 1278 | kex->kex_type = buffer_get_int(m); |
| 1279 | blob = buffer_get_string(m, &bloblen); |
| 1280 | buffer_init(&kex->my); |
| 1281 | buffer_append(&kex->my, blob, bloblen); |
| 1282 | xfree(blob); |
| 1283 | blob = buffer_get_string(m, &bloblen); |
| 1284 | buffer_init(&kex->peer); |
| 1285 | buffer_append(&kex->peer, blob, bloblen); |
| 1286 | xfree(blob); |
| 1287 | kex->done = 1; |
| 1288 | kex->flags = buffer_get_int(m); |
| 1289 | kex->client_version_string = buffer_get_string(m, NULL); |
| 1290 | kex->server_version_string = buffer_get_string(m, NULL); |
| 1291 | kex->load_host_key=&get_hostkey_by_type; |
| 1292 | kex->host_key_index=&get_hostkey_index; |
| 1293 | |
| 1294 | return (kex); |
| 1295 | } |
| 1296 | |
| 1297 | /* This function requries careful sanity checking */ |
| 1298 | |
| 1299 | void |
| 1300 | mm_get_keystate(struct monitor *monitor) |
| 1301 | { |
| 1302 | Buffer m; |
| 1303 | u_char *blob, *p; |
| 1304 | u_int bloblen, plen; |
| 1305 | |
| 1306 | debug3("%s: Waiting for new keys", __FUNCTION__); |
| 1307 | |
| 1308 | buffer_init(&m); |
| 1309 | mm_request_receive_expect(monitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); |
| 1310 | if (!compat20) { |
| 1311 | child_state.ssh1protoflags = buffer_get_int(&m); |
| 1312 | child_state.ssh1cipher = buffer_get_int(&m); |
| 1313 | child_state.ivout = buffer_get_string(&m, |
| 1314 | &child_state.ivoutlen); |
| 1315 | child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); |
| 1316 | goto skip; |
| 1317 | } else { |
| 1318 | /* Get the Kex for rekeying */ |
| 1319 | *monitor->m_pkex = mm_get_kex(&m); |
| 1320 | } |
| 1321 | |
| 1322 | blob = buffer_get_string(&m, &bloblen); |
| 1323 | current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); |
| 1324 | xfree(blob); |
| 1325 | |
| 1326 | debug3("%s: Waiting for second key", __FUNCTION__); |
| 1327 | blob = buffer_get_string(&m, &bloblen); |
| 1328 | current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); |
| 1329 | xfree(blob); |
| 1330 | |
| 1331 | /* Now get sequence numbers for the packets */ |
| 1332 | packet_set_seqnr(MODE_OUT, buffer_get_int(&m)); |
| 1333 | packet_set_seqnr(MODE_IN, buffer_get_int(&m)); |
| 1334 | |
| 1335 | skip: |
| 1336 | /* Get the key context */ |
| 1337 | child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); |
| 1338 | child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); |
| 1339 | |
| 1340 | debug3("%s: Getting compression state", __FUNCTION__); |
| 1341 | /* Get compression state */ |
| 1342 | p = buffer_get_string(&m, &plen); |
| 1343 | if (plen != sizeof(child_state.outgoing)) |
| 1344 | fatal("%s: bad request size", __FUNCTION__); |
| 1345 | memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); |
| 1346 | xfree(p); |
| 1347 | |
| 1348 | p = buffer_get_string(&m, &plen); |
| 1349 | if (plen != sizeof(child_state.incoming)) |
| 1350 | fatal("%s: bad request size", __FUNCTION__); |
| 1351 | memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); |
| 1352 | xfree(p); |
| 1353 | |
| 1354 | /* Network I/O buffers */ |
| 1355 | debug3("%s: Getting Network I/O buffers", __FUNCTION__); |
| 1356 | child_state.input = buffer_get_string(&m, &child_state.ilen); |
| 1357 | child_state.output = buffer_get_string(&m, &child_state.olen); |
| 1358 | |
| 1359 | buffer_free(&m); |
| 1360 | } |
| 1361 | |
| 1362 | |
| 1363 | /* Allocation functions for zlib */ |
| 1364 | void * |
| 1365 | mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) |
| 1366 | { |
| 1367 | void *address; |
| 1368 | |
| 1369 | address = mm_malloc(mm, size * ncount); |
| 1370 | |
| 1371 | return (address); |
| 1372 | } |
| 1373 | |
| 1374 | void |
| 1375 | mm_zfree(struct mm_master *mm, void *address) |
| 1376 | { |
| 1377 | mm_free(mm, address); |
| 1378 | } |
| 1379 | |
| 1380 | void |
| 1381 | mm_init_compression(struct mm_master *mm) |
| 1382 | { |
| 1383 | outgoing_stream.zalloc = (alloc_func)mm_zalloc; |
| 1384 | outgoing_stream.zfree = (free_func)mm_zfree; |
| 1385 | outgoing_stream.opaque = mm; |
| 1386 | |
| 1387 | incoming_stream.zalloc = (alloc_func)mm_zalloc; |
| 1388 | incoming_stream.zfree = (free_func)mm_zfree; |
| 1389 | incoming_stream.opaque = mm; |
| 1390 | } |
| 1391 | |
| 1392 | /* XXX */ |
| 1393 | |
| 1394 | #define FD_CLOSEONEXEC(x) do { \ |
| 1395 | if (fcntl(x, F_SETFD, 1) == -1) \ |
| 1396 | fatal("fcntl(%d, F_SETFD)", x); \ |
| 1397 | } while (0) |
| 1398 | |
| 1399 | static void |
| 1400 | monitor_socketpair(int *pair) |
| 1401 | { |
| 1402 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) |
| 1403 | fatal("%s: socketpair", __FUNCTION__); |
| 1404 | FD_CLOSEONEXEC(pair[0]); |
| 1405 | FD_CLOSEONEXEC(pair[1]); |
| 1406 | } |
| 1407 | |
| 1408 | #define MM_MEMSIZE 65536 |
| 1409 | |
| 1410 | struct monitor * |
| 1411 | monitor_init(void) |
| 1412 | { |
| 1413 | struct monitor *mon; |
| 1414 | int pair[2]; |
| 1415 | |
| 1416 | mon = xmalloc(sizeof(*mon)); |
| 1417 | |
| 1418 | monitor_socketpair(pair); |
| 1419 | |
| 1420 | mon->m_recvfd = pair[0]; |
| 1421 | mon->m_sendfd = pair[1]; |
| 1422 | |
| 1423 | /* Used to share zlib space across processes */ |
| 1424 | mon->m_zback = mm_create(NULL, MM_MEMSIZE); |
| 1425 | mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); |
| 1426 | |
| 1427 | /* Compression needs to share state across borders */ |
| 1428 | mm_init_compression(mon->m_zlib); |
| 1429 | |
| 1430 | return mon; |
| 1431 | } |
| 1432 | |
| 1433 | void |
| 1434 | monitor_reinit(struct monitor *mon) |
| 1435 | { |
| 1436 | int pair[2]; |
| 1437 | |
| 1438 | monitor_socketpair(pair); |
| 1439 | |
| 1440 | mon->m_recvfd = pair[0]; |
| 1441 | mon->m_sendfd = pair[1]; |
| 1442 | } |