key.c

   1 /*
   2  * read_bignum():
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *
   5  * As far as I am concerned, the code I have written for this software
   6  * can be used freely for any purpose.  Any derived versions of this
   7  * software must be clearly marked as such, and if the derived work is
   8  * incompatible with the protocol description in the RFC file, it must be
   9  * called by a name other than "ssh" or "Secure Shell".
  10  *
  11  *
  12  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions
  16  * are met:
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  * 2. Redistributions in binary form must reproduce the above copyright
  20  *    notice, this list of conditions and the following disclaimer in the
  21  *    documentation and/or other materials provided with the distribution.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34 #include "includes.h"
  35 RCSID("$OpenBSD: key.c,v 1.57 2004/10/29 23:57:05 djm Exp $");
  36
  37 #include <openssl/evp.h>
  38
  39 #include "xmalloc.h"
  40 #include "key.h"
  41 #include "rsa.h"
  42 #include "uuencode.h"
  43 #include "buffer.h"
  44 #include "bufaux.h"
  45 #include "log.h"
  46
  47 Key *
  48 key_new(int type)
  49 {
  50         Key *k;
  51         RSA *rsa;
  52         DSA *dsa;
  53         k = xmalloc(sizeof(*k));
  54         k->type = type;
  55         k->flags = 0;
  56         k->dsa = NULL;
  57         k->rsa = NULL;
  58         switch (k->type) {
  59         case KEY_RSA1:
  60         case KEY_RSA:
  61                 if ((rsa = RSA_new()) == NULL)
  62                         fatal("key_new: RSA_new failed");
  63                 if ((rsa->n = BN_new()) == NULL)
  64                         fatal("key_new: BN_new failed");
  65                 if ((rsa->e = BN_new()) == NULL)
  66                         fatal("key_new: BN_new failed");
  67                 k->rsa = rsa;
  68                 break;
  69         case KEY_DSA:
  70                 if ((dsa = DSA_new()) == NULL)
  71                         fatal("key_new: DSA_new failed");
  72                 if ((dsa->p = BN_new()) == NULL)
  73                         fatal("key_new: BN_new failed");
  74                 if ((dsa->q = BN_new()) == NULL)
  75                         fatal("key_new: BN_new failed");
  76                 if ((dsa->g = BN_new()) == NULL)
  77                         fatal("key_new: BN_new failed");
  78                 if ((dsa->pub_key = BN_new()) == NULL)
  79                         fatal("key_new: BN_new failed");
  80                 k->dsa = dsa;
  81                 break;
  82         case KEY_UNSPEC:
  83                 break;
  84         default:
  85                 fatal("key_new: bad key type %d", k->type);
  86                 break;
  87         }
  88         return k;
  89 }
  90
  91 Key *
  92 key_new_private(int type)
  93 {
  94         Key *k = key_new(type);
  95         switch (k->type) {
  96         case KEY_RSA1:
  97         case KEY_RSA:
  98                 if ((k->rsa->d = BN_new()) == NULL)
  99                         fatal("key_new_private: BN_new failed");
 100                 if ((k->rsa->iqmp = BN_new()) == NULL)
 101                         fatal("key_new_private: BN_new failed");
 102                 if ((k->rsa->q = BN_new()) == NULL)
 103                         fatal("key_new_private: BN_new failed");
 104                 if ((k->rsa->p = BN_new()) == NULL)
 105                         fatal("key_new_private: BN_new failed");
 106                 if ((k->rsa->dmq1 = BN_new()) == NULL)
 107                         fatal("key_new_private: BN_new failed");
 108                 if ((k->rsa->dmp1 = BN_new()) == NULL)
 109                         fatal("key_new_private: BN_new failed");
 110                 break;
 111         case KEY_DSA:
 112                 if ((k->dsa->priv_key = BN_new()) == NULL)
 113                         fatal("key_new_private: BN_new failed");
 114                 break;
 115         case KEY_UNSPEC:
 116                 break;
 117         default:
 118                 break;
 119         }
 120         return k;
 121 }
 122
 123 void
 124 key_free(Key *k)
 125 {
 126         switch (k->type) {
 127         case KEY_RSA1:
 128         case KEY_RSA:
 129                 if (k->rsa != NULL)
 130                         RSA_free(k->rsa);
 131                 k->rsa = NULL;
 132                 break;
 133         case KEY_DSA:
 134                 if (k->dsa != NULL)
 135                         DSA_free(k->dsa);
 136                 k->dsa = NULL;
 137                 break;
 138         case KEY_UNSPEC:
 139                 break;
 140         default:
 141                 fatal("key_free: bad key type %d", k->type);
 142                 break;
 143         }
 144         xfree(k);
 145 }
 146
 147 int
 148 key_equal(const Key *a, const Key *b)
 149 {
 150         if (a == NULL || b == NULL || a->type != b->type)
 151                 return 0;
 152         switch (a->type) {
 153         case KEY_RSA1:
 154         case KEY_RSA:
 155                 return a->rsa != NULL && b->rsa != NULL &&
 156                     BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
 157                     BN_cmp(a->rsa->n, b->rsa->n) == 0;
 158                 break;
 159         case KEY_DSA:
 160                 return a->dsa != NULL && b->dsa != NULL &&
 161                     BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
 162                     BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
 163                     BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
 164                     BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
 165                 break;
 166         default:
 167                 fatal("key_equal: bad key type %d", a->type);
 168                 break;
 169         }
 170         return 0;
 171 }
 172
 173 u_char*
 174 key_fingerprint_raw(const Key *k, enum fp_type dgst_type,
 175     u_int *dgst_raw_length)
 176 {
 177         const EVP_MD *md = NULL;
 178         EVP_MD_CTX ctx;
 179         u_char *blob = NULL;
 180         u_char *retval = NULL;
 181         u_int len = 0;
 182         int nlen, elen;
 183
 184         *dgst_raw_length = 0;
 185
 186         switch (dgst_type) {
 187         case SSH_FP_MD5:
 188                 md = EVP_md5();
 189                 break;
 190         case SSH_FP_SHA1:
 191                 md = EVP_sha1();
 192                 break;
 193         default:
 194                 fatal("key_fingerprint_raw: bad digest type %d",
 195                     dgst_type);
 196         }
 197         switch (k->type) {
 198         case KEY_RSA1:
 199                 nlen = BN_num_bytes(k->rsa->n);
 200                 elen = BN_num_bytes(k->rsa->e);
 201                 len = nlen + elen;
 202                 blob = xmalloc(len);
 203                 BN_bn2bin(k->rsa->n, blob);
 204                 BN_bn2bin(k->rsa->e, blob + nlen);
 205                 break;
 206         case KEY_DSA:
 207         case KEY_RSA:
 208                 key_to_blob(k, &blob, &len);
 209                 break;
 210         case KEY_UNSPEC:
 211                 return retval;
 212                 break;
 213         default:
 214                 fatal("key_fingerprint_raw: bad key type %d", k->type);
 215                 break;
 216         }
 217         if (blob != NULL) {
 218                 retval = xmalloc(EVP_MAX_MD_SIZE);
 219                 EVP_DigestInit(&ctx, md);
 220                 EVP_DigestUpdate(&ctx, blob, len);
 221                 EVP_DigestFinal(&ctx, retval, dgst_raw_length);
 222                 memset(blob, 0, len);
 223                 xfree(blob);
 224         } else {
 225                 fatal("key_fingerprint_raw: blob is null");
 226         }
 227         return retval;
 228 }
 229
 230 static char *
 231 key_fingerprint_hex(u_char *dgst_raw, u_int dgst_raw_len)
 232 {
 233         char *retval;
 234         int i;
 235
 236         retval = xmalloc(dgst_raw_len * 3 + 1);
 237         retval[0] = '\0';
 238         for (i = 0; i < dgst_raw_len; i++) {
 239                 char hex[4];
 240                 snprintf(hex, sizeof(hex), "%02x:", dgst_raw[i]);
 241                 strlcat(retval, hex, dgst_raw_len * 3 + 1);
 242         }
 243
 244         /* Remove the trailing ':' character */
 245         retval[(dgst_raw_len * 3) - 1] = '\0';
 246         return retval;
 247 }
 248
 249 static char *
 250 key_fingerprint_bubblebabble(u_char *dgst_raw, u_int dgst_raw_len)
 251 {
 252         char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
 253         char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
 254             'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
 255         u_int i, j = 0, rounds, seed = 1;
 256         char *retval;
 257
 258         rounds = (dgst_raw_len / 2) + 1;
 259         retval = xmalloc(sizeof(char) * (rounds*6));
 260         retval[j++] = 'x';
 261         for (i = 0; i < rounds; i++) {
 262                 u_int idx0, idx1, idx2, idx3, idx4;
 263                 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) {
 264                         idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) +
 265                             seed) % 6;
 266                         idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15;
 267                         idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) +
 268                             (seed / 6)) % 6;
 269                         retval[j++] = vowels[idx0];
 270                         retval[j++] = consonants[idx1];
 271                         retval[j++] = vowels[idx2];
 272                         if ((i + 1) < rounds) {
 273                                 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15;
 274                                 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15;
 275                                 retval[j++] = consonants[idx3];
 276                                 retval[j++] = '-';
 277                                 retval[j++] = consonants[idx4];
 278                                 seed = ((seed * 5) +
 279                                     ((((u_int)(dgst_raw[2 * i])) * 7) +
 280                                     ((u_int)(dgst_raw[(2 * i) + 1])))) % 36;
 281                         }
 282                 } else {
 283                         idx0 = seed % 6;
 284                         idx1 = 16;
 285                         idx2 = seed / 6;
 286                         retval[j++] = vowels[idx0];
 287                         retval[j++] = consonants[idx1];
 288                         retval[j++] = vowels[idx2];
 289                 }
 290         }
 291         retval[j++] = 'x';
 292         retval[j++] = '\0';
 293         return retval;
 294 }
 295
 296 char *
 297 key_fingerprint(const Key *k, enum fp_type dgst_type, enum fp_rep dgst_rep)
 298 {
 299         char *retval = NULL;
 300         u_char *dgst_raw;
 301         u_int dgst_raw_len;
 302
 303         dgst_raw = key_fingerprint_raw(k, dgst_type, &dgst_raw_len);
 304         if (!dgst_raw)
 305                 fatal("key_fingerprint: null from key_fingerprint_raw()");
 306         switch (dgst_rep) {
 307         case SSH_FP_HEX:
 308                 retval = key_fingerprint_hex(dgst_raw, dgst_raw_len);
 309                 break;
 310         case SSH_FP_BUBBLEBABBLE:
 311                 retval = key_fingerprint_bubblebabble(dgst_raw, dgst_raw_len);
 312                 break;
 313         default:
 314                 fatal("key_fingerprint_ex: bad digest representation %d",
 315                     dgst_rep);
 316                 break;
 317         }
 318         memset(dgst_raw, 0, dgst_raw_len);
 319         xfree(dgst_raw);
 320         return retval;
 321 }
 322
 323 /*
 324  * Reads a multiple-precision integer in decimal from the buffer, and advances
 325  * the pointer.  The integer must already be initialized.  This function is
 326  * permitted to modify the buffer.  This leaves *cpp to point just beyond the
 327  * last processed (and maybe modified) character.  Note that this may modify
 328  * the buffer containing the number.
 329  */
 330 static int
 331 read_bignum(char **cpp, BIGNUM * value)
 332 {
 333         char *cp = *cpp;
 334         int old;
 335
 336         /* Skip any leading whitespace. */
 337         for (; *cp == ' ' || *cp == '\t'; cp++)
 338                 ;
 339
 340         /* Check that it begins with a decimal digit. */
 341         if (*cp < '0' || *cp > '9')
 342                 return 0;
 343
 344         /* Save starting position. */
 345         *cpp = cp;
 346
 347         /* Move forward until all decimal digits skipped. */
 348         for (; *cp >= '0' && *cp <= '9'; cp++)
 349                 ;
 350
 351         /* Save the old terminating character, and replace it by \0. */
 352         old = *cp;
 353         *cp = 0;
 354
 355         /* Parse the number. */
 356         if (BN_dec2bn(&value, *cpp) == 0)
 357                 return 0;
 358
 359         /* Restore old terminating character. */
 360         *cp = old;
 361
 362         /* Move beyond the number and return success. */
 363         *cpp = cp;
 364         return 1;
 365 }
 366
 367 static int
 368 write_bignum(FILE *f, BIGNUM *num)
 369 {
 370         char *buf = BN_bn2dec(num);
 371         if (buf == NULL) {
 372                 error("write_bignum: BN_bn2dec() failed");
 373                 return 0;
 374         }
 375         fprintf(f, " %s", buf);
 376         OPENSSL_free(buf);
 377         return 1;
 378 }
 379
 380 /* returns 1 ok, -1 error */
 381 int
 382 key_read(Key *ret, char **cpp)
 383 {
 384         Key *k;
 385         int success = -1;
 386         char *cp, *space;
 387         int len, n, type;
 388         u_int bits;
 389         u_char *blob;
 390
 391         cp = *cpp;
 392
 393         switch (ret->type) {
 394         case KEY_RSA1:
 395                 /* Get number of bits. */
 396                 if (*cp < '0' || *cp > '9')
 397                         return -1;      /* Bad bit count... */
 398                 for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
 399                         bits = 10 * bits + *cp - '0';
 400                 if (bits == 0)
 401                         return -1;
 402                 *cpp = cp;
 403                 /* Get public exponent, public modulus. */
 404                 if (!read_bignum(cpp, ret->rsa->e))
 405                         return -1;
 406                 if (!read_bignum(cpp, ret->rsa->n))
 407                         return -1;
 408                 success = 1;
 409                 break;
 410         case KEY_UNSPEC:
 411         case KEY_RSA:
 412         case KEY_DSA:
 413                 space = strchr(cp, ' ');
 414                 if (space == NULL) {
 415                         debug3("key_read: missing whitespace");
 416                         return -1;
 417                 }
 418                 *space = '\0';
 419                 type = key_type_from_name(cp);
 420                 *space = ' ';
 421                 if (type == KEY_UNSPEC) {
 422                         debug3("key_read: missing keytype");
 423                         return -1;
 424                 }
 425                 cp = space+1;
 426                 if (*cp == '\0') {
 427                         debug3("key_read: short string");
 428                         return -1;
 429                 }
 430                 if (ret->type == KEY_UNSPEC) {
 431                         ret->type = type;
 432                 } else if (ret->type != type) {
 433                         /* is a key, but different type */
 434                         debug3("key_read: type mismatch");
 435                         return -1;
 436                 }
 437                 len = 2*strlen(cp);
 438                 blob = xmalloc(len);
 439                 n = uudecode(cp, blob, len);
 440                 if (n < 0) {
 441                         error("key_read: uudecode %s failed", cp);
 442                         xfree(blob);
 443                         return -1;
 444                 }
 445                 k = key_from_blob(blob, (u_int)n);
 446                 xfree(blob);
 447                 if (k == NULL) {
 448                         error("key_read: key_from_blob %s failed", cp);
 449                         return -1;
 450                 }
 451                 if (k->type != type) {
 452                         error("key_read: type mismatch: encoding error");
 453                         key_free(k);
 454                         return -1;
 455                 }
 456 /*XXXX*/
 457                 if (ret->type == KEY_RSA) {
 458                         if (ret->rsa != NULL)
 459                                 RSA_free(ret->rsa);
 460                         ret->rsa = k->rsa;
 461                         k->rsa = NULL;
 462                         success = 1;
 463 #ifdef DEBUG_PK
 464                         RSA_print_fp(stderr, ret->rsa, 8);
 465 #endif
 466                 } else {
 467                         if (ret->dsa != NULL)
 468                                 DSA_free(ret->dsa);
 469                         ret->dsa = k->dsa;
 470                         k->dsa = NULL;
 471                         success = 1;
 472 #ifdef DEBUG_PK
 473                         DSA_print_fp(stderr, ret->dsa, 8);
 474 #endif
 475                 }
 476 /*XXXX*/
 477                 key_free(k);
 478                 if (success != 1)
 479                         break;
 480                 /* advance cp: skip whitespace and data */
 481                 while (*cp == ' ' || *cp == '\t')
 482                         cp++;
 483                 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
 484                         cp++;
 485                 *cpp = cp;
 486                 break;
 487         default:
 488                 fatal("key_read: bad key type: %d", ret->type);
 489                 break;
 490         }
 491         return success;
 492 }
 493
 494 int
 495 key_write(const Key *key, FILE *f)
 496 {
 497         int n, success = 0;
 498         u_int len, bits = 0;
 499         u_char *blob;
 500         char *uu;
 501
 502         if (key->type == KEY_RSA1 && key->rsa != NULL) {
 503                 /* size of modulus 'n' */
 504                 bits = BN_num_bits(key->rsa->n);
 505                 fprintf(f, "%u", bits);
 506                 if (write_bignum(f, key->rsa->e) &&
 507                     write_bignum(f, key->rsa->n)) {
 508                         success = 1;
 509                 } else {
 510                         error("key_write: failed for RSA key");
 511                 }
 512         } else if ((key->type == KEY_DSA && key->dsa != NULL) ||
 513             (key->type == KEY_RSA && key->rsa != NULL)) {
 514                 key_to_blob(key, &blob, &len);
 515                 uu = xmalloc(2*len);
 516                 n = uuencode(blob, len, uu, 2*len);
 517                 if (n > 0) {
 518                         fprintf(f, "%s %s", key_ssh_name(key), uu);
 519                         success = 1;
 520                 }
 521                 xfree(blob);
 522                 xfree(uu);
 523         }
 524         return success;
 525 }
 526
 527 const char *
 528 key_type(const Key *k)
 529 {
 530         switch (k->type) {
 531         case KEY_RSA1:
 532                 return "RSA1";
 533                 break;
 534         case KEY_RSA:
 535                 return "RSA";
 536                 break;
 537         case KEY_DSA:
 538                 return "DSA";
 539                 break;
 540         }
 541         return "unknown";
 542 }
 543
 544 const char *
 545 key_ssh_name(const Key *k)
 546 {
 547         switch (k->type) {
 548         case KEY_RSA:
 549                 return "ssh-rsa";
 550                 break;
 551         case KEY_DSA:
 552                 return "ssh-dss";
 553                 break;
 554         }
 555         return "ssh-unknown";
 556 }
 557
 558 u_int
 559 key_size(const Key *k)
 560 {
 561         switch (k->type) {
 562         case KEY_RSA1:
 563         case KEY_RSA:
 564                 return BN_num_bits(k->rsa->n);
 565                 break;
 566         case KEY_DSA:
 567                 return BN_num_bits(k->dsa->p);
 568                 break;
 569         }
 570         return 0;
 571 }
 572
 573 static RSA *
 574 rsa_generate_private_key(u_int bits)
 575 {
 576         RSA *private;
 577         private = RSA_generate_key(bits, 35, NULL, NULL);
 578         if (private == NULL)
 579                 fatal("rsa_generate_private_key: key generation failed.");
 580         return private;
 581 }
 582
 583 static DSA*
 584 dsa_generate_private_key(u_int bits)
 585 {
 586         DSA *private = DSA_generate_parameters(bits, NULL, 0, NULL, NULL, NULL, NULL);
 587         if (private == NULL)
 588                 fatal("dsa_generate_private_key: DSA_generate_parameters failed");
 589         if (!DSA_generate_key(private))
 590                 fatal("dsa_generate_private_key: DSA_generate_key failed.");
 591         if (private == NULL)
 592                 fatal("dsa_generate_private_key: NULL.");
 593         return private;
 594 }
 595
 596 Key *
 597 key_generate(int type, u_int bits)
 598 {
 599         Key *k = key_new(KEY_UNSPEC);
 600         switch (type) {
 601         case KEY_DSA:
 602                 k->dsa = dsa_generate_private_key(bits);
 603                 break;
 604         case KEY_RSA:
 605         case KEY_RSA1:
 606                 k->rsa = rsa_generate_private_key(bits);
 607                 break;
 608         default:
 609                 fatal("key_generate: unknown type %d", type);
 610         }
 611         k->type = type;
 612         return k;
 613 }
 614
 615 Key *
 616 key_from_private(const Key *k)
 617 {
 618         Key *n = NULL;
 619         switch (k->type) {
 620         case KEY_DSA:
 621                 n = key_new(k->type);
 622                 BN_copy(n->dsa->p, k->dsa->p);
 623                 BN_copy(n->dsa->q, k->dsa->q);
 624                 BN_copy(n->dsa->g, k->dsa->g);
 625                 BN_copy(n->dsa->pub_key, k->dsa->pub_key);
 626                 break;
 627         case KEY_RSA:
 628         case KEY_RSA1:
 629                 n = key_new(k->type);
 630                 BN_copy(n->rsa->n, k->rsa->n);
 631                 BN_copy(n->rsa->e, k->rsa->e);
 632                 break;
 633         default:
 634                 fatal("key_from_private: unknown type %d", k->type);
 635                 break;
 636         }
 637         return n;
 638 }
 639
 640 int
 641 key_type_from_name(char *name)
 642 {
 643         if (strcmp(name, "rsa1") == 0) {
 644                 return KEY_RSA1;
 645         } else if (strcmp(name, "rsa") == 0) {
 646                 return KEY_RSA;
 647         } else if (strcmp(name, "dsa") == 0) {
 648                 return KEY_DSA;
 649         } else if (strcmp(name, "ssh-rsa") == 0) {
 650                 return KEY_RSA;
 651         } else if (strcmp(name, "ssh-dss") == 0) {
 652                 return KEY_DSA;
 653         }
 654         debug2("key_type_from_name: unknown key type '%s'", name);
 655         return KEY_UNSPEC;
 656 }
 657
 658 int
 659 key_names_valid2(const char *names)
 660 {
 661         char *s, *cp, *p;
 662
 663         if (names == NULL || strcmp(names, "") == 0)
 664                 return 0;
 665         s = cp = xstrdup(names);
 666         for ((p = strsep(&cp, ",")); p && *p != '\0';
 667             (p = strsep(&cp, ","))) {
 668                 switch (key_type_from_name(p)) {
 669                 case KEY_RSA1:
 670                 case KEY_UNSPEC:
 671                         xfree(s);
 672                         return 0;
 673                 }
 674         }
 675         debug3("key names ok: [%s]", names);
 676         xfree(s);
 677         return 1;
 678 }
 679
 680 Key *
 681 key_from_blob(const u_char *blob, u_int blen)
 682 {
 683         Buffer b;
 684         int rlen, type;
 685         char *ktype = NULL;
 686         Key *key = NULL;
 687
 688 #ifdef DEBUG_PK
 689         dump_base64(stderr, blob, blen);
 690 #endif
 691         buffer_init(&b);
 692         buffer_append(&b, blob, blen);
 693         if ((ktype = buffer_get_string_ret(&b, NULL)) == NULL) {
 694                 error("key_from_blob: can't read key type");
 695                 goto out;
 696         }
 697
 698         type = key_type_from_name(ktype);
 699
 700         switch (type) {
 701         case KEY_RSA:
 702                 key = key_new(type);
 703                 if (buffer_get_bignum2_ret(&b, key->rsa->e) == -1 ||
 704                     buffer_get_bignum2_ret(&b, key->rsa->n) == -1) {
 705                         error("key_from_blob: can't read rsa key");
 706                         key_free(key);
 707                         key = NULL;
 708                         goto out;
 709                 }
 710 #ifdef DEBUG_PK
 711                 RSA_print_fp(stderr, key->rsa, 8);
 712 #endif
 713                 break;
 714         case KEY_DSA:
 715                 key = key_new(type);
 716                 if (buffer_get_bignum2_ret(&b, key->dsa->p) == -1 ||
 717                     buffer_get_bignum2_ret(&b, key->dsa->q) == -1 ||
 718                     buffer_get_bignum2_ret(&b, key->dsa->g) == -1 ||
 719                     buffer_get_bignum2_ret(&b, key->dsa->pub_key) == -1) {
 720                         error("key_from_blob: can't read dsa key");
 721                         key_free(key);
 722                         key = NULL;
 723                         goto out;
 724                 }
 725 #ifdef DEBUG_PK
 726                 DSA_print_fp(stderr, key->dsa, 8);
 727 #endif
 728                 break;
 729         case KEY_UNSPEC:
 730                 key = key_new(type);
 731                 break;
 732         default:
 733                 error("key_from_blob: cannot handle type %s", ktype);
 734                 goto out;
 735         }
 736         rlen = buffer_len(&b);
 737         if (key != NULL && rlen != 0)
 738                 error("key_from_blob: remaining bytes in key blob %d", rlen);
 739  out:
 740         if (ktype != NULL)
 741                 xfree(ktype);
 742         buffer_free(&b);
 743         return key;
 744 }
 745
 746 int
 747 key_to_blob(const Key *key, u_char **blobp, u_int *lenp)
 748 {
 749         Buffer b;
 750         int len;
 751
 752         if (key == NULL) {
 753                 error("key_to_blob: key == NULL");
 754                 return 0;
 755         }
 756         buffer_init(&b);
 757         switch (key->type) {
 758         case KEY_DSA:
 759                 buffer_put_cstring(&b, key_ssh_name(key));
 760                 buffer_put_bignum2(&b, key->dsa->p);
 761                 buffer_put_bignum2(&b, key->dsa->q);
 762                 buffer_put_bignum2(&b, key->dsa->g);
 763                 buffer_put_bignum2(&b, key->dsa->pub_key);
 764                 break;
 765         case KEY_RSA:
 766                 buffer_put_cstring(&b, key_ssh_name(key));
 767                 buffer_put_bignum2(&b, key->rsa->e);
 768                 buffer_put_bignum2(&b, key->rsa->n);
 769                 break;
 770         default:
 771                 error("key_to_blob: unsupported key type %d", key->type);
 772                 buffer_free(&b);
 773                 return 0;
 774         }
 775         len = buffer_len(&b);
 776         if (lenp != NULL)
 777                 *lenp = len;
 778         if (blobp != NULL) {
 779                 *blobp = xmalloc(len);
 780                 memcpy(*blobp, buffer_ptr(&b), len);
 781         }
 782         memset(buffer_ptr(&b), 0, len);
 783         buffer_free(&b);
 784         return len;
 785 }
 786
 787 int
 788 key_sign(
 789     const Key *key,
 790     u_char **sigp, u_int *lenp,
 791     const u_char *data, u_int datalen)
 792 {
 793         switch (key->type) {
 794         case KEY_DSA:
 795                 return ssh_dss_sign(key, sigp, lenp, data, datalen);
 796                 break;
 797         case KEY_RSA:
 798                 return ssh_rsa_sign(key, sigp, lenp, data, datalen);
 799                 break;
 800         default:
 801                 error("key_sign: invalid key type %d", key->type);
 802                 return -1;
 803                 break;
 804         }
 805 }
 806
 807 /*
 808  * key_verify returns 1 for a correct signature, 0 for an incorrect signature
 809  * and -1 on error.
 810  */
 811 int
 812 key_verify(
 813     const Key *key,
 814     const u_char *signature, u_int signaturelen,
 815     const u_char *data, u_int datalen)
 816 {
 817         if (signaturelen == 0)
 818                 return -1;
 819
 820         switch (key->type) {
 821         case KEY_DSA:
 822                 return ssh_dss_verify(key, signature, signaturelen, data, datalen);
 823                 break;
 824         case KEY_RSA:
 825                 return ssh_rsa_verify(key, signature, signaturelen, data, datalen);
 826                 break;
 827         default:
 828                 error("key_verify: invalid key type %d", key->type);
 829                 return -1;
 830                 break;
 831         }
 832 }
 833
 834 /* Converts a private to a public key */
 835 Key *
 836 key_demote(const Key *k)
 837 {
 838         Key *pk;
 839
 840         pk = xmalloc(sizeof(*pk));
 841         pk->type = k->type;
 842         pk->flags = k->flags;
 843         pk->dsa = NULL;
 844         pk->rsa = NULL;
 845
 846         switch (k->type) {
 847         case KEY_RSA1:
 848         case KEY_RSA:
 849                 if ((pk->rsa = RSA_new()) == NULL)
 850                         fatal("key_demote: RSA_new failed");
 851                 if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL)
 852                         fatal("key_demote: BN_dup failed");
 853                 if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL)
 854                         fatal("key_demote: BN_dup failed");
 855                 break;
 856         case KEY_DSA:
 857                 if ((pk->dsa = DSA_new()) == NULL)
 858                         fatal("key_demote: DSA_new failed");
 859                 if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL)
 860                         fatal("key_demote: BN_dup failed");
 861                 if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL)
 862                         fatal("key_demote: BN_dup failed");
 863                 if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL)
 864                         fatal("key_demote: BN_dup failed");
 865                 if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL)
 866                         fatal("key_demote: BN_dup failed");
 867                 break;
 868         default:
 869                 fatal("key_free: bad key type %d", k->type);
 870                 break;
 871         }
 872
 873         return (pk);
 874 }