1 /*- 2 * Copyright (c) 2009 The NetBSD Foundation, Inc. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to The NetBSD Foundation 6 * by Alistair Crooks (agc@NetBSD.org) 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 #include "config.h" 30 31 #ifdef HAVE_SYS_CDEFS_H 32 #include <sys/cdefs.h> 33 #endif 34 35 #include <sys/types.h> 36 #include <sys/stat.h> 37 #include <sys/param.h> 38 39 #include <arpa/inet.h> 40 41 #include <inttypes.h> 42 #include <stdio.h> 43 44 #include <stdlib.h> 45 #include <string.h> 46 47 #ifdef HAVE_UNISTD_H 48 #include <unistd.h> 49 #endif 50 51 #ifdef HAVE_LIMITS_H 52 #include <limits.h> 53 #endif 54 55 #ifdef HAVE_OPENSSL_CAST_H 56 #include <openssl/cast.h> 57 #endif 58 59 #include <openssl/pem.h> 60 61 #include "bufgap.h" 62 #include "fastctype.h" 63 64 #include "packet-parse.h" 65 #include "netpgpdefs.h" 66 #include "netpgpsdk.h" 67 #include "crypto.h" 68 #include "netpgpdigest.h" 69 #include "ops-ssh.h" 70 71 /* structure for earching for constant strings */ 72 typedef struct str_t { 73 const char *s; /* string */ 74 size_t len; /* its length */ 75 int type; /* return type */ 76 } str_t; 77 78 #ifndef USE_ARG 79 #define USE_ARG(x) /*LINTED*/(void)&x 80 #endif 81 82 static const uint8_t base64s[] = 83 /* 000 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" 84 /* 016 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" 85 /* 032 */ "\0\0\0\0\0\0\0\0\0\0\0?\0\0\0@" 86 /* 048 */ "56789:;<=>\0\0\0\0\0\0" 87 /* 064 */ "\0\1\2\3\4\5\6\7\10\11\12\13\14\15\16\17" 88 /* 080 */ "\20\21\22\23\24\25\26\27\30\31\32\0\0\0\0\0" 89 /* 096 */ "\0\33\34\35\36\37 !\"#$%&'()" 90 /* 112 */ "*+,-./01234\0\0\0\0\0" 91 /* 128 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" 92 /* 144 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" 93 /* 160 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" 94 /* 176 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" 95 /* 192 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" 96 /* 208 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" 97 /* 224 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" 98 /* 240 */ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"; 99 100 101 /* short function to decode from base64 */ 102 /* inspired by an ancient copy of b64.c, then rewritten, the bugs are all mine */ 103 static int 104 frombase64(char *dst, const char *src, size_t size, int flag) 105 { 106 uint8_t out[3]; 107 uint8_t in[4]; 108 uint8_t b; 109 size_t srcc; 110 int dstc; 111 int gotc; 112 int i; 113 114 USE_ARG(flag); 115 for (dstc = 0, srcc = 0 ; srcc < size; ) { 116 for (gotc = 0, i = 0; i < 4 && srcc < size; i++) { 117 for (b = 0x0; srcc < size && b == 0x0 ; ) { 118 b = base64s[(unsigned)src[srcc++]]; 119 } 120 if (srcc < size) { 121 gotc += 1; 122 if (b) { 123 in[i] = (uint8_t)(b - 1); 124 } 125 } else { 126 in[i] = 0x0; 127 } 128 } 129 if (gotc) { 130 out[0] = (uint8_t)((unsigned)in[0] << 2 | 131 (unsigned)in[1] >> 4); 132 out[1] = (uint8_t)((unsigned)in[1] << 4 | 133 (unsigned)in[2] >> 2); 134 out[2] = (uint8_t)(((in[2] << 6) & 0xc0) | in[3]); 135 for (i = 0; i < gotc - 1; i++) { 136 *dst++ = out[i]; 137 } 138 dstc += gotc - 1; 139 } 140 } 141 return dstc; 142 } 143 144 #define LINELEN 16 145 146 /* show hexadecimal/ascii dump */ 147 static void 148 show(const char *header, char *in, int len) 149 { 150 char line[LINELEN + 1]; 151 int i; 152 153 printf("%s%s", (header) ? header : "", (header) ? "\n" : ""); 154 printf("[%d chars]\n", len); 155 for (i = 0 ; i < len ; i++) { 156 if (i % LINELEN == 0) { 157 printf("%.5d | ", i); 158 } 159 printf("%.02x ", (uint8_t)in[i]); 160 line[i % LINELEN] = (isprint(in[i])) ? in[i] : '.'; 161 if (i % LINELEN == LINELEN - 1) { 162 line[LINELEN] = 0x0; 163 printf(" | %s\n", line); 164 } 165 } 166 for ( ; i % LINELEN != 0 ; i++) { 167 printf(" "); 168 line[i % LINELEN] = ' '; 169 } 170 line[LINELEN] = 0x0; 171 printf(" | %s\n", line); 172 } 173 174 /* get a bignum from the buffer gap */ 175 static BIGNUM * 176 getbignum(bufgap_t *bg, char *buf, const char *header) 177 { 178 uint32_t len; 179 BIGNUM *bignum; 180 181 (void) bufgap_getbin(bg, &len, sizeof(len)); 182 len = ntohl(len); 183 (void) bufgap_seek(bg, sizeof(len), BGFromHere, BGByte); 184 (void) bufgap_getbin(bg, buf, len); 185 bignum = BN_bin2bn((const unsigned char *)buf, (int)len, NULL); 186 if (__ops_get_debug_level(__FILE__)) { 187 show(header, buf, (int)len); 188 } 189 (void) bufgap_seek(bg, len, BGFromHere, BGByte); 190 return bignum; 191 } 192 193 static str_t pkatypes[] = { 194 { "ssh-rsa", 7, OPS_PKA_RSA }, 195 { "ssh-dsa", 7, OPS_PKA_DSA }, 196 { NULL, 0, 0 } 197 }; 198 199 /* look for a string in the given array */ 200 static int 201 findstr(str_t *array, const char *name) 202 { 203 str_t *sp; 204 205 for (sp = array ; sp->s ; sp++) { 206 if (strncmp(name, sp->s, sp->len) == 0) { 207 return sp->type; 208 } 209 } 210 return -1; 211 } 212 213 /* convert an ssh (host) pubkey to a pgp pubkey */ 214 int 215 __ops_ssh2pubkey(__ops_io_t *io, const char *f, __ops_key_t *key) 216 { 217 __ops_userid_t userid; 218 __ops_pubkey_t *pubkey; 219 struct stat st; 220 bufgap_t bg; 221 uint32_t len; 222 int64_t off; 223 char hostname[256]; 224 char owner[256]; 225 char *space; 226 char *buf; 227 char *bin; 228 int ok; 229 int cc; 230 231 (void) memset(&bg, 0x0, sizeof(bg)); 232 if (!bufgap_open(&bg, f)) { 233 (void) fprintf(stderr, "__ops_ssh2pubkey: can't open '%s'\n", f); 234 return 0; 235 } 236 (void)stat(f, &st); 237 if ((buf = calloc(1, (size_t)st.st_size)) == NULL) { 238 (void) fprintf(stderr, "can't calloc %zu bytes for '%s'\n", (size_t)st.st_size, f); 239 bufgap_close(&bg); 240 return 0; 241 } 242 if ((bin = calloc(1, (size_t)st.st_size)) == NULL) { 243 (void) fprintf(stderr, "can't calloc %zu bytes for '%s'\n", (size_t)st.st_size, f); 244 (void) free(buf); 245 bufgap_close(&bg); 246 return 0; 247 } 248 249 /* move past ascii type of key */ 250 while (bufgap_peek(&bg, 0) != ' ') { 251 bufgap_seek(&bg, 1, BGFromHere, BGByte); 252 } 253 bufgap_seek(&bg, 1, BGFromHere, BGByte); 254 off = bufgap_tell(&bg, BGFromBOF, BGByte); 255 256 /* convert from base64 to binary */ 257 cc = bufgap_getbin(&bg, buf, (size_t)st.st_size); 258 if ((space = strchr(buf, ' ')) != NULL) { 259 cc = (int)(space - buf); 260 } 261 if (__ops_get_debug_level(__FILE__)) { 262 show(NULL, buf, cc); 263 } 264 cc = frombase64(bin, buf, (size_t)cc, 0); 265 if (__ops_get_debug_level(__FILE__)) { 266 show("decoded base64:", bin, cc); 267 } 268 bufgap_delete(&bg, (uint64_t)bufgap_tell(&bg, BGFromEOF, BGByte)); 269 bufgap_insert(&bg, bin, cc); 270 bufgap_seek(&bg, off, BGFromBOF, BGByte); 271 272 /* get the type of key */ 273 (void) bufgap_getbin(&bg, &len, sizeof(len)); 274 len = ntohl(len); 275 (void) bufgap_seek(&bg, sizeof(len), BGFromHere, BGByte); 276 (void) bufgap_getbin(&bg, buf, len); 277 (void) bufgap_seek(&bg, len, BGFromHere, BGByte); 278 279 (void) memset(key, 0x0, sizeof(*key)); 280 pubkey = &key->key.seckey.pubkey; 281 pubkey->version = OPS_V4; 282 pubkey->birthtime = st.st_mtime; 283 /* get key type */ 284 ok = 1; 285 switch (pubkey->alg = findstr(pkatypes, buf)) { 286 case OPS_PKA_RSA: 287 /* get the 'e' param of the key */ 288 pubkey->key.rsa.e = getbignum(&bg, buf, "RSA E"); 289 /* get the 'n' param of the key */ 290 pubkey->key.rsa.n = getbignum(&bg, buf, "RSA N"); 291 break; 292 case OPS_PKA_DSA: 293 /* get the 'p' param of the key */ 294 pubkey->key.dsa.p = getbignum(&bg, buf, "DSA P"); 295 /* get the 'q' param of the key */ 296 pubkey->key.dsa.q = getbignum(&bg, buf, "DSA Q"); 297 /* get the 'g' param of the key */ 298 pubkey->key.dsa.g = getbignum(&bg, buf, "DSA G"); 299 /* get the 'y' param of the key */ 300 pubkey->key.dsa.y = getbignum(&bg, buf, "DSA Y"); 301 break; 302 default: 303 (void) fprintf(stderr, "Unrecognised pubkey type %d for '%s'\n", 304 pubkey->alg, f); 305 ok = 0; 306 break; 307 } 308 309 /* check for stragglers */ 310 if (ok && bufgap_tell(&bg, BGFromEOF, BGByte) > 0) { 311 printf("%"PRIi64" bytes left\n", bufgap_tell(&bg, BGFromEOF, BGByte)); 312 printf("[%s]\n", bufgap_getstr(&bg)); 313 ok = 0; 314 } 315 if (ok) { 316 (void) memset(&userid, 0x0, sizeof(userid)); 317 (void) gethostname(hostname, sizeof(hostname)); 318 if (strlen(space + 1) - 1 == 0) { 319 (void) snprintf(owner, sizeof(owner), "<root@%s>", 320 hostname); 321 } else { 322 (void) snprintf(owner, sizeof(owner), "<%.*s>", 323 (int)strlen(space + 1) - 1, 324 space + 1); 325 } 326 (void) __ops_asprintf((char **)(void *)&userid.userid, 327 "%s (%s) %s", 328 hostname, 329 f, 330 owner); 331 __ops_keyid(key->key_id, sizeof(key->key_id), pubkey); 332 __ops_add_userid(key, &userid); 333 __ops_fingerprint(&key->fingerprint, pubkey); 334 free(userid.userid); 335 if (__ops_get_debug_level(__FILE__)) { 336 __ops_print_keydata(io, key, "pub", pubkey); 337 } 338 } 339 (void) free(bin); 340 (void) free(buf); 341 bufgap_close(&bg); 342 return ok; 343 } 344 345 /* convert an ssh (host) seckey to a pgp seckey */ 346 int 347 __ops_ssh2seckey(__ops_io_t *io, const char *f, __ops_key_t *key, __ops_pubkey_t *pubkey) 348 { 349 unsigned char sesskey[CAST_KEY_LENGTH]; 350 unsigned char hashed[OPS_SHA1_HASH_SIZE]; 351 __ops_crypt_t crypted; 352 __ops_hash_t hash; 353 unsigned int done = 0; 354 unsigned int i = 0; 355 356 /* XXX - check for rsa/dsa */ 357 if (!openssl_read_pem_seckey(f, key, "ssh-rsa", 0)) { 358 return 0; 359 } 360 if (__ops_get_debug_level(__FILE__)) { 361 __ops_print_keydata(io, key, "sec", &key->key.seckey.pubkey); 362 } 363 /* let's add some sane defaults */ 364 (void) memcpy(&key->key.seckey.pubkey, pubkey, sizeof(*pubkey)); 365 key->key.seckey.s2k_usage = OPS_S2KU_ENCRYPTED_AND_HASHED; 366 key->key.seckey.alg = OPS_SA_CAST5; 367 key->key.seckey.s2k_specifier = OPS_S2KS_SALTED; 368 key->key.seckey.hash_alg = OPS_HASH_SHA1; 369 for (done = 0, i = 0; done < CAST_KEY_LENGTH; i++) { 370 unsigned char zero = 0; 371 unsigned j; 372 int needed; 373 int size; 374 375 needed = CAST_KEY_LENGTH - done; 376 size = MIN(needed, OPS_SHA1_HASH_SIZE); 377 378 __ops_hash_any(&hash, key->key.seckey.hash_alg); 379 if (!hash.init(&hash)) { 380 (void) fprintf(stderr, "write_seckey_body: bad alloc\n"); 381 return 0; 382 } 383 384 /* preload if iterating */ 385 for (j = 0; j < i; j++) { 386 /* 387 * Coverity shows a DEADCODE error on this 388 * line. This is expected since the hardcoded 389 * use of SHA1 and CAST5 means that it will 390 * not used. This will change however when 391 * other algorithms are supported. 392 */ 393 hash.add(&hash, &zero, 1); 394 } 395 396 if (key->key.seckey.s2k_specifier == OPS_S2KS_SALTED) { 397 hash.add(&hash, key->key.seckey.salt, OPS_SALT_SIZE); 398 } 399 hash.finish(&hash, hashed); 400 401 /* 402 * if more in hash than is needed by session key, use 403 * the leftmost octets 404 */ 405 (void) memcpy(&sesskey[i * OPS_SHA1_HASH_SIZE], 406 hashed, (unsigned)size); 407 done += (unsigned)size; 408 if (done > CAST_KEY_LENGTH) { 409 (void) fprintf(stderr, 410 "write_seckey_body: short add\n"); 411 return 0; 412 } 413 } 414 __ops_crypt_any(&crypted, key->key.seckey.alg); 415 crypted.set_iv(&crypted, key->key.seckey.iv); 416 crypted.set_crypt_key(&crypted, sesskey); 417 __ops_encrypt_init(&crypted); 418 key->key.seckey.pubkey.alg = OPS_PKA_RSA; 419 __ops_fingerprint(&key->fingerprint, pubkey); 420 __ops_keyid(key->key_id, sizeof(key->key_id), pubkey); 421 return 1; 422 } 423 424 /* read a key from the ssh file, and add it to a keyring */ 425 int 426 __ops_ssh2_readkeys(__ops_io_t *io, __ops_keyring_t *pubring, 427 __ops_keyring_t *secring, const char *pubfile, 428 const char *secfile) 429 { 430 __ops_key_t *pubkey; 431 __ops_key_t *seckey; 432 __ops_key_t key; 433 434 pubkey = NULL; 435 (void) memset(&key, 0x0, sizeof(key)); 436 if (pubfile) { 437 if (__ops_get_debug_level(__FILE__)) { 438 (void) fprintf(io->errs, "__ops_ssh2_readkeys: pubfile '%s'\n", pubfile); 439 } 440 __ops_ssh2pubkey(io, pubfile, &key); 441 EXPAND_ARRAY(pubring, key); 442 pubkey = &pubring->keys[pubring->keyc++]; 443 (void) memcpy(pubkey, &key, sizeof(key)); 444 pubkey->type = OPS_PTAG_CT_PUBLIC_KEY; 445 } 446 if (secfile) { 447 if (__ops_get_debug_level(__FILE__)) { 448 (void) fprintf(io->errs, "__ops_ssh2_readkeys: secfile '%s'\n", secfile); 449 } 450 if (pubkey == NULL) { 451 pubkey = &pubring->keys[0]; 452 } 453 (void) __ops_ssh2seckey(io, secfile, &key, &pubkey->key.pubkey); 454 EXPAND_ARRAY(secring, key); 455 seckey = &secring->keys[secring->keyc++]; 456 (void) memcpy(seckey, &key, sizeof(key)); 457 seckey->type = OPS_PTAG_CT_SECRET_KEY; 458 } 459 return 1; 460 } 461