crypto/openssh/key.c

   1 /* $OpenBSD: key.c,v 1.78 2008/07/07 23:32:51 stevesk Exp $ */
   2 /*
   3  * read_bignum():
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *
   6  * As far as I am concerned, the code I have written for this software
   7  * can be used freely for any purpose.  Any derived versions of this
   8  * software must be clearly marked as such, and if the derived work is
   9  * incompatible with the protocol description in the RFC file, it must be
  10  * called by a name other than "ssh" or "Secure Shell".
  11  *
  12  *
  13  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  14  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  28  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "includes.h"
  38
  39 #include <sys/param.h>
  40 #include <sys/types.h>
  41
  42 #include <openssl/evp.h>
  43 #include <openbsd-compat/openssl-compat.h>
  44
  45 #include <stdarg.h>
  46 #include <stdio.h>
  47 #include <string.h>
  48
  49 #include "xmalloc.h"
  50 #include "key.h"
  51 #include "rsa.h"
  52 #include "uuencode.h"
  53 #include "buffer.h"
  54 #include "log.h"
  55
  56 Key *
  57 key_new(int type)
  58 {
  59         Key *k;
  60         RSA *rsa;
  61         DSA *dsa;
  62         k = xcalloc(1, sizeof(*k));
  63         k->type = type;
  64         k->dsa = NULL;
  65         k->rsa = NULL;
  66         switch (k->type) {
  67         case KEY_RSA1:
  68         case KEY_RSA:
  69                 if ((rsa = RSA_new()) == NULL)
  70                         fatal("key_new: RSA_new failed");
  71                 if ((rsa->n = BN_new()) == NULL)
  72                         fatal("key_new: BN_new failed");
  73                 if ((rsa->e = BN_new()) == NULL)
  74                         fatal("key_new: BN_new failed");
  75                 k->rsa = rsa;
  76                 break;
  77         case KEY_DSA:
  78                 if ((dsa = DSA_new()) == NULL)
  79                         fatal("key_new: DSA_new failed");
  80                 if ((dsa->p = BN_new()) == NULL)
  81                         fatal("key_new: BN_new failed");
  82                 if ((dsa->q = BN_new()) == NULL)
  83                         fatal("key_new: BN_new failed");
  84                 if ((dsa->g = BN_new()) == NULL)
  85                         fatal("key_new: BN_new failed");
  86                 if ((dsa->pub_key = BN_new()) == NULL)
  87                         fatal("key_new: BN_new failed");
  88                 k->dsa = dsa;
  89                 break;
  90         case KEY_UNSPEC:
  91                 break;
  92         default:
  93                 fatal("key_new: bad key type %d", k->type);
  94                 break;
  95         }
  96         return k;
  97 }
  98
  99 Key *
 100 key_new_private(int type)
 101 {
 102         Key *k = key_new(type);
 103         switch (k->type) {
 104         case KEY_RSA1:
 105         case KEY_RSA:
 106                 if ((k->rsa->d = BN_new()) == NULL)
 107                         fatal("key_new_private: BN_new failed");
 108                 if ((k->rsa->iqmp = BN_new()) == NULL)
 109                         fatal("key_new_private: BN_new failed");
 110                 if ((k->rsa->q = BN_new()) == NULL)
 111                         fatal("key_new_private: BN_new failed");
 112                 if ((k->rsa->p = BN_new()) == NULL)
 113                         fatal("key_new_private: BN_new failed");
 114                 if ((k->rsa->dmq1 = BN_new()) == NULL)
 115                         fatal("key_new_private: BN_new failed");
 116                 if ((k->rsa->dmp1 = BN_new()) == NULL)
 117                         fatal("key_new_private: BN_new failed");
 118                 break;
 119         case KEY_DSA:
 120                 if ((k->dsa->priv_key = BN_new()) == NULL)
 121                         fatal("key_new_private: BN_new failed");
 122                 break;
 123         case KEY_UNSPEC:
 124                 break;
 125         default:
 126                 break;
 127         }
 128         return k;
 129 }
 130
 131 void
 132 key_free(Key *k)
 133 {
 134         if (k == NULL)
 135                 fatal("key_free: key is NULL");
 136         switch (k->type) {
 137         case KEY_RSA1:
 138         case KEY_RSA:
 139                 if (k->rsa != NULL)
 140                         RSA_free(k->rsa);
 141                 k->rsa = NULL;
 142                 break;
 143         case KEY_DSA:
 144                 if (k->dsa != NULL)
 145                         DSA_free(k->dsa);
 146                 k->dsa = NULL;
 147                 break;
 148         case KEY_UNSPEC:
 149                 break;
 150         default:
 151                 fatal("key_free: bad key type %d", k->type);
 152                 break;
 153         }
 154         xfree(k);
 155 }
 156
 157 int
 158 key_equal(const Key *a, const Key *b)
 159 {
 160         if (a == NULL || b == NULL || a->type != b->type)
 161                 return 0;
 162         switch (a->type) {
 163         case KEY_RSA1:
 164         case KEY_RSA:
 165                 return a->rsa != NULL && b->rsa != NULL &&
 166                     BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
 167                     BN_cmp(a->rsa->n, b->rsa->n) == 0;
 168         case KEY_DSA:
 169                 return a->dsa != NULL && b->dsa != NULL &&
 170                     BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
 171                     BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
 172                     BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
 173                     BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
 174         default:
 175                 fatal("key_equal: bad key type %d", a->type);
 176         }
 177         /* NOTREACHED */
 178 }
 179
 180 u_char*
 181 key_fingerprint_raw(const Key *k, enum fp_type dgst_type,
 182     u_int *dgst_raw_length)
 183 {
 184         const EVP_MD *md = NULL;
 185         EVP_MD_CTX ctx;
 186         u_char *blob = NULL;
 187         u_char *retval = NULL;
 188         u_int len = 0;
 189         int nlen, elen;
 190
 191         *dgst_raw_length = 0;
 192
 193         switch (dgst_type) {
 194         case SSH_FP_MD5:
 195                 md = EVP_md5();
 196                 break;
 197         case SSH_FP_SHA1:
 198                 md = EVP_sha1();
 199                 break;
 200         default:
 201                 fatal("key_fingerprint_raw: bad digest type %d",
 202                     dgst_type);
 203         }
 204         switch (k->type) {
 205         case KEY_RSA1:
 206                 nlen = BN_num_bytes(k->rsa->n);
 207                 elen = BN_num_bytes(k->rsa->e);
 208                 len = nlen + elen;
 209                 blob = xmalloc(len);
 210                 BN_bn2bin(k->rsa->n, blob);
 211                 BN_bn2bin(k->rsa->e, blob + nlen);
 212                 break;
 213         case KEY_DSA:
 214         case KEY_RSA:
 215                 key_to_blob(k, &blob, &len);
 216                 break;
 217         case KEY_UNSPEC:
 218                 return retval;
 219         default:
 220                 fatal("key_fingerprint_raw: bad key type %d", k->type);
 221                 break;
 222         }
 223         if (blob != NULL) {
 224                 retval = xmalloc(EVP_MAX_MD_SIZE);
 225                 EVP_DigestInit(&ctx, md);
 226                 EVP_DigestUpdate(&ctx, blob, len);
 227                 EVP_DigestFinal(&ctx, retval, dgst_raw_length);
 228                 memset(blob, 0, len);
 229                 xfree(blob);
 230         } else {
 231                 fatal("key_fingerprint_raw: blob is null");
 232         }
 233         return retval;
 234 }
 235
 236 static char *
 237 key_fingerprint_hex(u_char *dgst_raw, u_int dgst_raw_len)
 238 {
 239         char *retval;
 240         u_int i;
 241
 242         retval = xcalloc(1, dgst_raw_len * 3 + 1);
 243         for (i = 0; i < dgst_raw_len; i++) {
 244                 char hex[4];
 245                 snprintf(hex, sizeof(hex), "%02x:", dgst_raw[i]);
 246                 strlcat(retval, hex, dgst_raw_len * 3 + 1);
 247         }
 248
 249         /* Remove the trailing ':' character */
 250         retval[(dgst_raw_len * 3) - 1] = '\0';
 251         return retval;
 252 }
 253
 254 static char *
 255 key_fingerprint_bubblebabble(u_char *dgst_raw, u_int dgst_raw_len)
 256 {
 257         char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
 258         char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
 259             'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
 260         u_int i, j = 0, rounds, seed = 1;
 261         char *retval;
 262
 263         rounds = (dgst_raw_len / 2) + 1;
 264         retval = xcalloc((rounds * 6), sizeof(char));
 265         retval[j++] = 'x';
 266         for (i = 0; i < rounds; i++) {
 267                 u_int idx0, idx1, idx2, idx3, idx4;
 268                 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) {
 269                         idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) +
 270                             seed) % 6;
 271                         idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15;
 272                         idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) +
 273                             (seed / 6)) % 6;
 274                         retval[j++] = vowels[idx0];
 275                         retval[j++] = consonants[idx1];
 276                         retval[j++] = vowels[idx2];
 277                         if ((i + 1) < rounds) {
 278                                 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15;
 279                                 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15;
 280                                 retval[j++] = consonants[idx3];
 281                                 retval[j++] = '-';
 282                                 retval[j++] = consonants[idx4];
 283                                 seed = ((seed * 5) +
 284                                     ((((u_int)(dgst_raw[2 * i])) * 7) +
 285                                     ((u_int)(dgst_raw[(2 * i) + 1])))) % 36;
 286                         }
 287                 } else {
 288                         idx0 = seed % 6;
 289                         idx1 = 16;
 290                         idx2 = seed / 6;
 291                         retval[j++] = vowels[idx0];
 292                         retval[j++] = consonants[idx1];
 293                         retval[j++] = vowels[idx2];
 294                 }
 295         }
 296         retval[j++] = 'x';
 297         retval[j++] = '\0';
 298         return retval;
 299 }
 300
 301 /*
 302  * Draw an ASCII-Art representing the fingerprint so human brain can
 303  * profit from its built-in pattern recognition ability.
 304  * This technique is called "random art" and can be found in some
 305  * scientific publications like this original paper:
 306  *
 307  * "Hash Visualization: a New Technique to improve Real-World Security",
 308  * Perrig A. and Song D., 1999, International Workshop on Cryptographic
 309  * Techniques and E-Commerce (CrypTEC '99)
 310  * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
 311  *
 312  * The subject came up in a talk by Dan Kaminsky, too.
 313  *
 314  * If you see the picture is different, the key is different.
 315  * If the picture looks the same, you still know nothing.
 316  *
 317  * The algorithm used here is a worm crawling over a discrete plane,
 318  * leaving a trace (augmenting the field) everywhere it goes.
 319  * Movement is taken from dgst_raw 2bit-wise.  Bumping into walls
 320  * makes the respective movement vector be ignored for this turn.
 321  * Graphs are not unambiguous, because circles in graphs can be
 322  * walked in either direction.
 323  */
 324
 325 /*
 326  * Field sizes for the random art.  Have to be odd, so the starting point
 327  * can be in the exact middle of the picture, and FLDBASE should be >=8 .
 328  * Else pictures would be too dense, and drawing the frame would
 329  * fail, too, because the key type would not fit in anymore.
 330  */
 331 #define FLDBASE         8
 332 #define FLDSIZE_Y       (FLDBASE + 1)
 333 #define FLDSIZE_X       (FLDBASE * 2 + 1)
 334 static char *
 335 key_fingerprint_randomart(u_char *dgst_raw, u_int dgst_raw_len, const Key *k)
 336 {
 337         /*
 338          * Chars to be used after each other every time the worm
 339          * intersects with itself.  Matter of taste.
 340          */
 341         char    *augmentation_string = " .o+=*BOX@%&#/^SE";
 342         char    *retval, *p;
 343         u_char   field[FLDSIZE_X][FLDSIZE_Y];
 344         u_int    i, b;
 345         int      x, y;
 346         size_t   len = strlen(augmentation_string) - 1;
 347
 348         retval = xcalloc(1, (FLDSIZE_X + 3) * (FLDSIZE_Y + 2));
 349
 350         /* initialize field */
 351         memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char));
 352         x = FLDSIZE_X / 2;
 353         y = FLDSIZE_Y / 2;
 354
 355         /* process raw key */
 356         for (i = 0; i < dgst_raw_len; i++) {
 357                 int input;
 358                 /* each byte conveys four 2-bit move commands */
 359                 input = dgst_raw[i];
 360                 for (b = 0; b < 4; b++) {
 361                         /* evaluate 2 bit, rest is shifted later */
 362                         x += (input & 0x1) ? 1 : -1;
 363                         y += (input & 0x2) ? 1 : -1;
 364
 365                         /* assure we are still in bounds */
 366                         x = MAX(x, 0);
 367                         y = MAX(y, 0);
 368                         x = MIN(x, FLDSIZE_X - 1);
 369                         y = MIN(y, FLDSIZE_Y - 1);
 370
 371                         /* augment the field */
 372                         field[x][y]++;
 373                         input = input >> 2;
 374                 }
 375         }
 376
 377         /* mark starting point and end point*/
 378         field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1;
 379         field[x][y] = len;
 380
 381         /* fill in retval */
 382         snprintf(retval, FLDSIZE_X, "+--[%4s %4u]", key_type(k), key_size(k));
 383         p = strchr(retval, '\0');
 384
 385         /* output upper border */
 386         for (i = p - retval - 1; i < FLDSIZE_X; i++)
 387                 *p++ = '-';
 388         *p++ = '+';
 389         *p++ = '\n';
 390
 391         /* output content */
 392         for (y = 0; y < FLDSIZE_Y; y++) {
 393                 *p++ = '|';
 394                 for (x = 0; x < FLDSIZE_X; x++)
 395                         *p++ = augmentation_string[MIN(field[x][y], len)];
 396                 *p++ = '|';
 397                 *p++ = '\n';
 398         }
 399
 400         /* output lower border */
 401         *p++ = '+';
 402         for (i = 0; i < FLDSIZE_X; i++)
 403                 *p++ = '-';
 404         *p++ = '+';
 405
 406         return retval;
 407 }
 408
 409 char *
 410 key_fingerprint(const Key *k, enum fp_type dgst_type, enum fp_rep dgst_rep)
 411 {
 412         char *retval = NULL;
 413         u_char *dgst_raw;
 414         u_int dgst_raw_len;
 415
 416         dgst_raw = key_fingerprint_raw(k, dgst_type, &dgst_raw_len);
 417         if (!dgst_raw)
 418                 fatal("key_fingerprint: null from key_fingerprint_raw()");
 419         switch (dgst_rep) {
 420         case SSH_FP_HEX:
 421                 retval = key_fingerprint_hex(dgst_raw, dgst_raw_len);
 422                 break;
 423         case SSH_FP_BUBBLEBABBLE:
 424                 retval = key_fingerprint_bubblebabble(dgst_raw, dgst_raw_len);
 425                 break;
 426         case SSH_FP_RANDOMART:
 427                 retval = key_fingerprint_randomart(dgst_raw, dgst_raw_len, k);
 428                 break;
 429         default:
 430                 fatal("key_fingerprint_ex: bad digest representation %d",
 431                     dgst_rep);
 432                 break;
 433         }
 434         memset(dgst_raw, 0, dgst_raw_len);
 435         xfree(dgst_raw);
 436         return retval;
 437 }
 438
 439 /*
 440  * Reads a multiple-precision integer in decimal from the buffer, and advances
 441  * the pointer.  The integer must already be initialized.  This function is
 442  * permitted to modify the buffer.  This leaves *cpp to point just beyond the
 443  * last processed (and maybe modified) character.  Note that this may modify
 444  * the buffer containing the number.
 445  */
 446 static int
 447 read_bignum(char **cpp, BIGNUM * value)
 448 {
 449         char *cp = *cpp;
 450         int old;
 451
 452         /* Skip any leading whitespace. */
 453         for (; *cp == ' ' || *cp == '\t'; cp++)
 454                 ;
 455
 456         /* Check that it begins with a decimal digit. */
 457         if (*cp < '0' || *cp > '9')
 458                 return 0;
 459
 460         /* Save starting position. */
 461         *cpp = cp;
 462
 463         /* Move forward until all decimal digits skipped. */
 464         for (; *cp >= '0' && *cp <= '9'; cp++)
 465                 ;
 466
 467         /* Save the old terminating character, and replace it by \0. */
 468         old = *cp;
 469         *cp = 0;
 470
 471         /* Parse the number. */
 472         if (BN_dec2bn(&value, *cpp) == 0)
 473                 return 0;
 474
 475         /* Restore old terminating character. */
 476         *cp = old;
 477
 478         /* Move beyond the number and return success. */
 479         *cpp = cp;
 480         return 1;
 481 }
 482
 483 static int
 484 write_bignum(FILE *f, BIGNUM *num)
 485 {
 486         char *buf = BN_bn2dec(num);
 487         if (buf == NULL) {
 488                 error("write_bignum: BN_bn2dec() failed");
 489                 return 0;
 490         }
 491         fprintf(f, " %s", buf);
 492         OPENSSL_free(buf);
 493         return 1;
 494 }
 495
 496 /* returns 1 ok, -1 error */
 497 int
 498 key_read(Key *ret, char **cpp)
 499 {
 500         Key *k;
 501         int success = -1;
 502         char *cp, *space;
 503         int len, n, type;
 504         u_int bits;
 505         u_char *blob;
 506
 507         cp = *cpp;
 508
 509         switch (ret->type) {
 510         case KEY_RSA1:
 511                 /* Get number of bits. */
 512                 if (*cp < '0' || *cp > '9')
 513                         return -1;      /* Bad bit count... */
 514                 for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
 515                         bits = 10 * bits + *cp - '0';
 516                 if (bits == 0)
 517                         return -1;
 518                 *cpp = cp;
 519                 /* Get public exponent, public modulus. */
 520                 if (!read_bignum(cpp, ret->rsa->e))
 521                         return -1;
 522                 if (!read_bignum(cpp, ret->rsa->n))
 523                         return -1;
 524                 success = 1;
 525                 break;
 526         case KEY_UNSPEC:
 527         case KEY_RSA:
 528         case KEY_DSA:
 529                 space = strchr(cp, ' ');
 530                 if (space == NULL) {
 531                         debug3("key_read: missing whitespace");
 532                         return -1;
 533                 }
 534                 *space = '\0';
 535                 type = key_type_from_name(cp);
 536                 *space = ' ';
 537                 if (type == KEY_UNSPEC) {
 538                         debug3("key_read: missing keytype");
 539                         return -1;
 540                 }
 541                 cp = space+1;
 542                 if (*cp == '\0') {
 543                         debug3("key_read: short string");
 544                         return -1;
 545                 }
 546                 if (ret->type == KEY_UNSPEC) {
 547                         ret->type = type;
 548                 } else if (ret->type != type) {
 549                         /* is a key, but different type */
 550                         debug3("key_read: type mismatch");
 551                         return -1;
 552                 }
 553                 len = 2*strlen(cp);
 554                 blob = xmalloc(len);
 555                 n = uudecode(cp, blob, len);
 556                 if (n < 0) {
 557                         error("key_read: uudecode %s failed", cp);
 558                         xfree(blob);
 559                         return -1;
 560                 }
 561                 k = key_from_blob(blob, (u_int)n);
 562                 xfree(blob);
 563                 if (k == NULL) {
 564                         error("key_read: key_from_blob %s failed", cp);
 565                         return -1;
 566                 }
 567                 if (k->type != type) {
 568                         error("key_read: type mismatch: encoding error");
 569                         key_free(k);
 570                         return -1;
 571                 }
 572 /*XXXX*/
 573                 if (ret->type == KEY_RSA) {
 574                         if (ret->rsa != NULL)
 575                                 RSA_free(ret->rsa);
 576                         ret->rsa = k->rsa;
 577                         k->rsa = NULL;
 578                         success = 1;
 579 #ifdef DEBUG_PK
 580                         RSA_print_fp(stderr, ret->rsa, 8);
 581 #endif
 582                 } else {
 583                         if (ret->dsa != NULL)
 584                                 DSA_free(ret->dsa);
 585                         ret->dsa = k->dsa;
 586                         k->dsa = NULL;
 587                         success = 1;
 588 #ifdef DEBUG_PK
 589                         DSA_print_fp(stderr, ret->dsa, 8);
 590 #endif
 591                 }
 592 /*XXXX*/
 593                 key_free(k);
 594                 if (success != 1)
 595                         break;
 596                 /* advance cp: skip whitespace and data */
 597                 while (*cp == ' ' || *cp == '\t')
 598                         cp++;
 599                 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
 600                         cp++;
 601                 *cpp = cp;
 602                 break;
 603         default:
 604                 fatal("key_read: bad key type: %d", ret->type);
 605                 break;
 606         }
 607         return success;
 608 }
 609
 610 int
 611 key_write(const Key *key, FILE *f)
 612 {
 613         int n, success = 0;
 614         u_int len, bits = 0;
 615         u_char *blob;
 616         char *uu;
 617
 618         if (key->type == KEY_RSA1 && key->rsa != NULL) {
 619                 /* size of modulus 'n' */
 620                 bits = BN_num_bits(key->rsa->n);
 621                 fprintf(f, "%u", bits);
 622                 if (write_bignum(f, key->rsa->e) &&
 623                     write_bignum(f, key->rsa->n)) {
 624                         success = 1;
 625                 } else {
 626                         error("key_write: failed for RSA key");
 627                 }
 628         } else if ((key->type == KEY_DSA && key->dsa != NULL) ||
 629             (key->type == KEY_RSA && key->rsa != NULL)) {
 630                 key_to_blob(key, &blob, &len);
 631                 uu = xmalloc(2*len);
 632                 n = uuencode(blob, len, uu, 2*len);
 633                 if (n > 0) {
 634                         fprintf(f, "%s %s", key_ssh_name(key), uu);
 635                         success = 1;
 636                 }
 637                 xfree(blob);
 638                 xfree(uu);
 639         }
 640         return success;
 641 }
 642
 643 const char *
 644 key_type(const Key *k)
 645 {
 646         switch (k->type) {
 647         case KEY_RSA1:
 648                 return "RSA1";
 649         case KEY_RSA:
 650                 return "RSA";
 651         case KEY_DSA:
 652                 return "DSA";
 653         }
 654         return "unknown";
 655 }
 656
 657 const char *
 658 key_ssh_name(const Key *k)
 659 {
 660         switch (k->type) {
 661         case KEY_RSA:
 662                 return "ssh-rsa";
 663         case KEY_DSA:
 664                 return "ssh-dss";
 665         }
 666         return "ssh-unknown";
 667 }
 668
 669 u_int
 670 key_size(const Key *k)
 671 {
 672         switch (k->type) {
 673         case KEY_RSA1:
 674         case KEY_RSA:
 675                 return BN_num_bits(k->rsa->n);
 676         case KEY_DSA:
 677                 return BN_num_bits(k->dsa->p);
 678         }
 679         return 0;
 680 }
 681
 682 static RSA *
 683 rsa_generate_private_key(u_int bits)
 684 {
 685         RSA *private;
 686
 687         private = RSA_generate_key(bits, 35, NULL, NULL);
 688         if (private == NULL)
 689                 fatal("rsa_generate_private_key: key generation failed.");
 690         return private;
 691 }
 692
 693 static DSA*
 694 dsa_generate_private_key(u_int bits)
 695 {
 696         DSA *private = DSA_generate_parameters(bits, NULL, 0, NULL, NULL, NULL, NULL);
 697
 698         if (private == NULL)
 699                 fatal("dsa_generate_private_key: DSA_generate_parameters failed");
 700         if (!DSA_generate_key(private))
 701                 fatal("dsa_generate_private_key: DSA_generate_key failed.");
 702         if (private == NULL)
 703                 fatal("dsa_generate_private_key: NULL.");
 704         return private;
 705 }
 706
 707 Key *
 708 key_generate(int type, u_int bits)
 709 {
 710         Key *k = key_new(KEY_UNSPEC);
 711         switch (type) {
 712         case KEY_DSA:
 713                 k->dsa = dsa_generate_private_key(bits);
 714                 break;
 715         case KEY_RSA:
 716         case KEY_RSA1:
 717                 k->rsa = rsa_generate_private_key(bits);
 718                 break;
 719         default:
 720                 fatal("key_generate: unknown type %d", type);
 721         }
 722         k->type = type;
 723         return k;
 724 }
 725
 726 Key *
 727 key_from_private(const Key *k)
 728 {
 729         Key *n = NULL;
 730         switch (k->type) {
 731         case KEY_DSA:
 732                 n = key_new(k->type);
 733                 if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) ||
 734                     (BN_copy(n->dsa->q, k->dsa->q) == NULL) ||
 735                     (BN_copy(n->dsa->g, k->dsa->g) == NULL) ||
 736                     (BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL))
 737                         fatal("key_from_private: BN_copy failed");
 738                 break;
 739         case KEY_RSA:
 740         case KEY_RSA1:
 741                 n = key_new(k->type);
 742                 if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) ||
 743                     (BN_copy(n->rsa->e, k->rsa->e) == NULL))
 744                         fatal("key_from_private: BN_copy failed");
 745                 break;
 746         default:
 747                 fatal("key_from_private: unknown type %d", k->type);
 748                 break;
 749         }
 750         return n;
 751 }
 752
 753 int
 754 key_type_from_name(char *name)
 755 {
 756         if (strcmp(name, "rsa1") == 0) {
 757                 return KEY_RSA1;
 758         } else if (strcmp(name, "rsa") == 0) {
 759                 return KEY_RSA;
 760         } else if (strcmp(name, "dsa") == 0) {
 761                 return KEY_DSA;
 762         } else if (strcmp(name, "ssh-rsa") == 0) {
 763                 return KEY_RSA;
 764         } else if (strcmp(name, "ssh-dss") == 0) {
 765                 return KEY_DSA;
 766         }
 767         debug2("key_type_from_name: unknown key type '%s'", name);
 768         return KEY_UNSPEC;
 769 }
 770
 771 int
 772 key_names_valid2(const char *names)
 773 {
 774         char *s, *cp, *p;
 775
 776         if (names == NULL || strcmp(names, "") == 0)
 777                 return 0;
 778         s = cp = xstrdup(names);
 779         for ((p = strsep(&cp, ",")); p && *p != '\0';
 780             (p = strsep(&cp, ","))) {
 781                 switch (key_type_from_name(p)) {
 782                 case KEY_RSA1:
 783                 case KEY_UNSPEC:
 784                         xfree(s);
 785                         return 0;
 786                 }
 787         }
 788         debug3("key names ok: [%s]", names);
 789         xfree(s);
 790         return 1;
 791 }
 792
 793 Key *
 794 key_from_blob(const u_char *blob, u_int blen)
 795 {
 796         Buffer b;
 797         int rlen, type;
 798         char *ktype = NULL;
 799         Key *key = NULL;
 800
 801 #ifdef DEBUG_PK
 802         dump_base64(stderr, blob, blen);
 803 #endif
 804         buffer_init(&b);
 805         buffer_append(&b, blob, blen);
 806         if ((ktype = buffer_get_string_ret(&b, NULL)) == NULL) {
 807                 error("key_from_blob: can't read key type");
 808                 goto out;
 809         }
 810
 811         type = key_type_from_name(ktype);
 812
 813         switch (type) {
 814         case KEY_RSA:
 815                 key = key_new(type);
 816                 if (buffer_get_bignum2_ret(&b, key->rsa->e) == -1 ||
 817                     buffer_get_bignum2_ret(&b, key->rsa->n) == -1) {
 818                         error("key_from_blob: can't read rsa key");
 819                         key_free(key);
 820                         key = NULL;
 821                         goto out;
 822                 }
 823 #ifdef DEBUG_PK
 824                 RSA_print_fp(stderr, key->rsa, 8);
 825 #endif
 826                 break;
 827         case KEY_DSA:
 828                 key = key_new(type);
 829                 if (buffer_get_bignum2_ret(&b, key->dsa->p) == -1 ||
 830                     buffer_get_bignum2_ret(&b, key->dsa->q) == -1 ||
 831                     buffer_get_bignum2_ret(&b, key->dsa->g) == -1 ||
 832                     buffer_get_bignum2_ret(&b, key->dsa->pub_key) == -1) {
 833                         error("key_from_blob: can't read dsa key");
 834                         key_free(key);
 835                         key = NULL;
 836                         goto out;
 837                 }
 838 #ifdef DEBUG_PK
 839                 DSA_print_fp(stderr, key->dsa, 8);
 840 #endif
 841                 break;
 842         case KEY_UNSPEC:
 843                 key = key_new(type);
 844                 break;
 845         default:
 846                 error("key_from_blob: cannot handle type %s", ktype);
 847                 goto out;
 848         }
 849         rlen = buffer_len(&b);
 850         if (key != NULL && rlen != 0)
 851                 error("key_from_blob: remaining bytes in key blob %d", rlen);
 852  out:
 853         if (ktype != NULL)
 854                 xfree(ktype);
 855         buffer_free(&b);
 856         return key;
 857 }
 858
 859 int
 860 key_to_blob(const Key *key, u_char **blobp, u_int *lenp)
 861 {
 862         Buffer b;
 863         int len;
 864
 865         if (key == NULL) {
 866                 error("key_to_blob: key == NULL");
 867                 return 0;
 868         }
 869         buffer_init(&b);
 870         switch (key->type) {
 871         case KEY_DSA:
 872                 buffer_put_cstring(&b, key_ssh_name(key));
 873                 buffer_put_bignum2(&b, key->dsa->p);
 874                 buffer_put_bignum2(&b, key->dsa->q);
 875                 buffer_put_bignum2(&b, key->dsa->g);
 876                 buffer_put_bignum2(&b, key->dsa->pub_key);
 877                 break;
 878         case KEY_RSA:
 879                 buffer_put_cstring(&b, key_ssh_name(key));
 880                 buffer_put_bignum2(&b, key->rsa->e);
 881                 buffer_put_bignum2(&b, key->rsa->n);
 882                 break;
 883         default:
 884                 error("key_to_blob: unsupported key type %d", key->type);
 885                 buffer_free(&b);
 886                 return 0;
 887         }
 888         len = buffer_len(&b);
 889         if (lenp != NULL)
 890                 *lenp = len;
 891         if (blobp != NULL) {
 892                 *blobp = xmalloc(len);
 893                 memcpy(*blobp, buffer_ptr(&b), len);
 894         }
 895         memset(buffer_ptr(&b), 0, len);
 896         buffer_free(&b);
 897         return len;
 898 }
 899
 900 int
 901 key_sign(
 902     const Key *key,
 903     u_char **sigp, u_int *lenp,
 904     const u_char *data, u_int datalen)
 905 {
 906         switch (key->type) {
 907         case KEY_DSA:
 908                 return ssh_dss_sign(key, sigp, lenp, data, datalen);
 909         case KEY_RSA:
 910                 return ssh_rsa_sign(key, sigp, lenp, data, datalen);
 911         default:
 912                 error("key_sign: invalid key type %d", key->type);
 913                 return -1;
 914         }
 915 }
 916
 917 /*
 918  * key_verify returns 1 for a correct signature, 0 for an incorrect signature
 919  * and -1 on error.
 920  */
 921 int
 922 key_verify(
 923     const Key *key,
 924     const u_char *signature, u_int signaturelen,
 925     const u_char *data, u_int datalen)
 926 {
 927         if (signaturelen == 0)
 928                 return -1;
 929
 930         switch (key->type) {
 931         case KEY_DSA:
 932                 return ssh_dss_verify(key, signature, signaturelen, data, datalen);
 933         case KEY_RSA:
 934                 return ssh_rsa_verify(key, signature, signaturelen, data, datalen);
 935         default:
 936                 error("key_verify: invalid key type %d", key->type);
 937                 return -1;
 938         }
 939 }
 940
 941 /* Converts a private to a public key */
 942 Key *
 943 key_demote(const Key *k)
 944 {
 945         Key *pk;
 946
 947         pk = xcalloc(1, sizeof(*pk));
 948         pk->type = k->type;
 949         pk->flags = k->flags;
 950         pk->dsa = NULL;
 951         pk->rsa = NULL;
 952
 953         switch (k->type) {
 954         case KEY_RSA1:
 955         case KEY_RSA:
 956                 if ((pk->rsa = RSA_new()) == NULL)
 957                         fatal("key_demote: RSA_new failed");
 958                 if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL)
 959                         fatal("key_demote: BN_dup failed");
 960                 if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL)
 961                         fatal("key_demote: BN_dup failed");
 962                 break;
 963         case KEY_DSA:
 964                 if ((pk->dsa = DSA_new()) == NULL)
 965                         fatal("key_demote: DSA_new failed");
 966                 if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL)
 967                         fatal("key_demote: BN_dup failed");
 968                 if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL)
 969                         fatal("key_demote: BN_dup failed");
 970                 if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL)
 971                         fatal("key_demote: BN_dup failed");
 972                 if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL)
 973                         fatal("key_demote: BN_dup failed");
 974                 break;
 975         default:
 976                 fatal("key_free: bad key type %d", k->type);
 977                 break;
 978         }
 979
 980         return (pk);
 981 }