1/* $OpenBSD: key.c,v 1.104 2013/05/19 02:42:42 djm 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#include "misc.h" 56#include "ssh2.h" 57 58static int to_blob(const Key *, u_char **, u_int *, int); 59 60static struct KeyCert * 61cert_new(void) 62{ 63 struct KeyCert *cert; 64 65 cert = xcalloc(1, sizeof(*cert)); 66 buffer_init(&cert->certblob); 67 buffer_init(&cert->critical); 68 buffer_init(&cert->extensions); 69 cert->key_id = NULL; 70 cert->principals = NULL; 71 cert->signature_key = NULL; 72 return cert; 73} 74 75Key * 76key_new(int type) 77{ 78 Key *k; 79 RSA *rsa; 80 DSA *dsa; 81 k = xcalloc(1, sizeof(*k)); 82 k->type = type; 83 k->ecdsa = NULL; 84 k->ecdsa_nid = -1; 85 k->dsa = NULL; 86 k->rsa = NULL; 87 k->cert = NULL; 88 switch (k->type) { 89 case KEY_RSA1: 90 case KEY_RSA: 91 case KEY_RSA_CERT_V00: 92 case KEY_RSA_CERT: 93 if ((rsa = RSA_new()) == NULL) 94 fatal("key_new: RSA_new failed"); 95 if ((rsa->n = BN_new()) == NULL) 96 fatal("key_new: BN_new failed"); 97 if ((rsa->e = BN_new()) == NULL) 98 fatal("key_new: BN_new failed"); 99 k->rsa = rsa; 100 break; 101 case KEY_DSA: 102 case KEY_DSA_CERT_V00: 103 case KEY_DSA_CERT: 104 if ((dsa = DSA_new()) == NULL) 105 fatal("key_new: DSA_new failed"); 106 if ((dsa->p = BN_new()) == NULL) 107 fatal("key_new: BN_new failed"); 108 if ((dsa->q = BN_new()) == NULL) 109 fatal("key_new: BN_new failed"); 110 if ((dsa->g = BN_new()) == NULL) 111 fatal("key_new: BN_new failed"); 112 if ((dsa->pub_key = BN_new()) == NULL) 113 fatal("key_new: BN_new failed"); 114 k->dsa = dsa; 115 break; 116#ifdef OPENSSL_HAS_ECC 117 case KEY_ECDSA: 118 case KEY_ECDSA_CERT: 119 /* Cannot do anything until we know the group */ 120 break; 121#endif 122 case KEY_UNSPEC: 123 break; 124 default: 125 fatal("key_new: bad key type %d", k->type); 126 break; 127 } 128 129 if (key_is_cert(k)) 130 k->cert = cert_new(); 131 132 return k; 133} 134 135void 136key_add_private(Key *k) 137{ 138 switch (k->type) { 139 case KEY_RSA1: 140 case KEY_RSA: 141 case KEY_RSA_CERT_V00: 142 case KEY_RSA_CERT: 143 if ((k->rsa->d = BN_new()) == NULL) 144 fatal("key_new_private: BN_new failed"); 145 if ((k->rsa->iqmp = BN_new()) == NULL) 146 fatal("key_new_private: BN_new failed"); 147 if ((k->rsa->q = BN_new()) == NULL) 148 fatal("key_new_private: BN_new failed"); 149 if ((k->rsa->p = BN_new()) == NULL) 150 fatal("key_new_private: BN_new failed"); 151 if ((k->rsa->dmq1 = BN_new()) == NULL) 152 fatal("key_new_private: BN_new failed"); 153 if ((k->rsa->dmp1 = BN_new()) == NULL) 154 fatal("key_new_private: BN_new failed"); 155 break; 156 case KEY_DSA: 157 case KEY_DSA_CERT_V00: 158 case KEY_DSA_CERT: 159 if ((k->dsa->priv_key = BN_new()) == NULL) 160 fatal("key_new_private: BN_new failed"); 161 break; 162 case KEY_ECDSA: 163 case KEY_ECDSA_CERT: 164 /* Cannot do anything until we know the group */ 165 break; 166 case KEY_UNSPEC: 167 break; 168 default: 169 break; 170 } 171} 172 173Key * 174key_new_private(int type) 175{ 176 Key *k = key_new(type); 177 178 key_add_private(k); 179 return k; 180} 181 182static void 183cert_free(struct KeyCert *cert) 184{ 185 u_int i; 186 187 buffer_free(&cert->certblob); 188 buffer_free(&cert->critical); 189 buffer_free(&cert->extensions); 190 free(cert->key_id); 191 for (i = 0; i < cert->nprincipals; i++) 192 free(cert->principals[i]); 193 free(cert->principals); 194 if (cert->signature_key != NULL) 195 key_free(cert->signature_key); 196 free(cert); 197} 198 199void 200key_free(Key *k) 201{ 202 if (k == NULL) 203 fatal("key_free: key is NULL"); 204 switch (k->type) { 205 case KEY_RSA1: 206 case KEY_RSA: 207 case KEY_RSA_CERT_V00: 208 case KEY_RSA_CERT: 209 if (k->rsa != NULL) 210 RSA_free(k->rsa); 211 k->rsa = NULL; 212 break; 213 case KEY_DSA: 214 case KEY_DSA_CERT_V00: 215 case KEY_DSA_CERT: 216 if (k->dsa != NULL) 217 DSA_free(k->dsa); 218 k->dsa = NULL; 219 break; 220#ifdef OPENSSL_HAS_ECC 221 case KEY_ECDSA: 222 case KEY_ECDSA_CERT: 223 if (k->ecdsa != NULL) 224 EC_KEY_free(k->ecdsa); 225 k->ecdsa = NULL; 226 break; 227#endif 228 case KEY_UNSPEC: 229 break; 230 default: 231 fatal("key_free: bad key type %d", k->type); 232 break; 233 } 234 if (key_is_cert(k)) { 235 if (k->cert != NULL) 236 cert_free(k->cert); 237 k->cert = NULL; 238 } 239 240 free(k); 241} 242 243static int 244cert_compare(struct KeyCert *a, struct KeyCert *b) 245{ 246 if (a == NULL && b == NULL) 247 return 1; 248 if (a == NULL || b == NULL) 249 return 0; 250 if (buffer_len(&a->certblob) != buffer_len(&b->certblob)) 251 return 0; 252 if (timingsafe_bcmp(buffer_ptr(&a->certblob), buffer_ptr(&b->certblob), 253 buffer_len(&a->certblob)) != 0) 254 return 0; 255 return 1; 256} 257 258/* 259 * Compare public portions of key only, allowing comparisons between 260 * certificates and plain keys too. 261 */ 262int 263key_equal_public(const Key *a, const Key *b) 264{ 265#ifdef OPENSSL_HAS_ECC 266 BN_CTX *bnctx; 267#endif 268 269 if (a == NULL || b == NULL || 270 key_type_plain(a->type) != key_type_plain(b->type)) 271 return 0; 272 273 switch (a->type) { 274 case KEY_RSA1: 275 case KEY_RSA_CERT_V00: 276 case KEY_RSA_CERT: 277 case KEY_RSA: 278 return a->rsa != NULL && b->rsa != NULL && 279 BN_cmp(a->rsa->e, b->rsa->e) == 0 && 280 BN_cmp(a->rsa->n, b->rsa->n) == 0; 281 case KEY_DSA_CERT_V00: 282 case KEY_DSA_CERT: 283 case KEY_DSA: 284 return a->dsa != NULL && b->dsa != NULL && 285 BN_cmp(a->dsa->p, b->dsa->p) == 0 && 286 BN_cmp(a->dsa->q, b->dsa->q) == 0 && 287 BN_cmp(a->dsa->g, b->dsa->g) == 0 && 288 BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0; 289#ifdef OPENSSL_HAS_ECC 290 case KEY_ECDSA_CERT: 291 case KEY_ECDSA: 292 if (a->ecdsa == NULL || b->ecdsa == NULL || 293 EC_KEY_get0_public_key(a->ecdsa) == NULL || 294 EC_KEY_get0_public_key(b->ecdsa) == NULL) 295 return 0; 296 if ((bnctx = BN_CTX_new()) == NULL) 297 fatal("%s: BN_CTX_new failed", __func__); 298 if (EC_GROUP_cmp(EC_KEY_get0_group(a->ecdsa), 299 EC_KEY_get0_group(b->ecdsa), bnctx) != 0 || 300 EC_POINT_cmp(EC_KEY_get0_group(a->ecdsa), 301 EC_KEY_get0_public_key(a->ecdsa), 302 EC_KEY_get0_public_key(b->ecdsa), bnctx) != 0) { 303 BN_CTX_free(bnctx); 304 return 0; 305 } 306 BN_CTX_free(bnctx); 307 return 1; 308#endif /* OPENSSL_HAS_ECC */ 309 default: 310 fatal("key_equal: bad key type %d", a->type); 311 } 312 /* NOTREACHED */ 313} 314 315int 316key_equal(const Key *a, const Key *b) 317{ 318 if (a == NULL || b == NULL || a->type != b->type) 319 return 0; 320 if (key_is_cert(a)) { 321 if (!cert_compare(a->cert, b->cert)) 322 return 0; 323 } 324 return key_equal_public(a, b); 325} 326 327u_char* 328key_fingerprint_raw(const Key *k, enum fp_type dgst_type, 329 u_int *dgst_raw_length) 330{ 331 const EVP_MD *md = NULL; 332 EVP_MD_CTX ctx; 333 u_char *blob = NULL; 334 u_char *retval = NULL; 335 u_int len = 0; 336 int nlen, elen; 337 338 *dgst_raw_length = 0; 339 340 switch (dgst_type) { 341 case SSH_FP_MD5: 342 md = EVP_md5(); 343 break; 344 case SSH_FP_SHA1: 345 md = EVP_sha1(); 346 break; 347#ifdef HAVE_EVP_SHA256 348 case SSH_FP_SHA256: 349 md = EVP_sha256(); 350 break; 351#endif 352 default: 353 fatal("key_fingerprint_raw: bad digest type %d", 354 dgst_type); 355 } 356 switch (k->type) { 357 case KEY_RSA1: 358 nlen = BN_num_bytes(k->rsa->n); 359 elen = BN_num_bytes(k->rsa->e); 360 len = nlen + elen; 361 blob = xmalloc(len); 362 BN_bn2bin(k->rsa->n, blob); 363 BN_bn2bin(k->rsa->e, blob + nlen); 364 break; 365 case KEY_DSA: 366 case KEY_ECDSA: 367 case KEY_RSA: 368 key_to_blob(k, &blob, &len); 369 break; 370 case KEY_DSA_CERT_V00: 371 case KEY_RSA_CERT_V00: 372 case KEY_DSA_CERT: 373 case KEY_ECDSA_CERT: 374 case KEY_RSA_CERT: 375 /* We want a fingerprint of the _key_ not of the cert */ 376 to_blob(k, &blob, &len, 1); 377 break; 378 case KEY_UNSPEC: 379 return retval; 380 default: 381 fatal("key_fingerprint_raw: bad key type %d", k->type); 382 break; 383 } 384 if (blob != NULL) { 385 retval = xmalloc(EVP_MAX_MD_SIZE); 386 EVP_DigestInit(&ctx, md); 387 EVP_DigestUpdate(&ctx, blob, len); 388 EVP_DigestFinal(&ctx, retval, dgst_raw_length); 389 memset(blob, 0, len); 390 free(blob); 391 } else { 392 fatal("key_fingerprint_raw: blob is null"); 393 } 394 return retval; 395} 396 397static char * 398key_fingerprint_hex(u_char *dgst_raw, u_int dgst_raw_len) 399{ 400 char *retval; 401 u_int i; 402 403 retval = xcalloc(1, dgst_raw_len * 3 + 1); 404 for (i = 0; i < dgst_raw_len; i++) { 405 char hex[4]; 406 snprintf(hex, sizeof(hex), "%02x:", dgst_raw[i]); 407 strlcat(retval, hex, dgst_raw_len * 3 + 1); 408 } 409 410 /* Remove the trailing ':' character */ 411 retval[(dgst_raw_len * 3) - 1] = '\0'; 412 return retval; 413} 414 415static char * 416key_fingerprint_bubblebabble(u_char *dgst_raw, u_int dgst_raw_len) 417{ 418 char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' }; 419 char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm', 420 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' }; 421 u_int i, j = 0, rounds, seed = 1; 422 char *retval; 423 424 rounds = (dgst_raw_len / 2) + 1; 425 retval = xcalloc((rounds * 6), sizeof(char)); 426 retval[j++] = 'x'; 427 for (i = 0; i < rounds; i++) { 428 u_int idx0, idx1, idx2, idx3, idx4; 429 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) { 430 idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) + 431 seed) % 6; 432 idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15; 433 idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) + 434 (seed / 6)) % 6; 435 retval[j++] = vowels[idx0]; 436 retval[j++] = consonants[idx1]; 437 retval[j++] = vowels[idx2]; 438 if ((i + 1) < rounds) { 439 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15; 440 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15; 441 retval[j++] = consonants[idx3]; 442 retval[j++] = '-'; 443 retval[j++] = consonants[idx4]; 444 seed = ((seed * 5) + 445 ((((u_int)(dgst_raw[2 * i])) * 7) + 446 ((u_int)(dgst_raw[(2 * i) + 1])))) % 36; 447 } 448 } else { 449 idx0 = seed % 6; 450 idx1 = 16; 451 idx2 = seed / 6; 452 retval[j++] = vowels[idx0]; 453 retval[j++] = consonants[idx1]; 454 retval[j++] = vowels[idx2]; 455 } 456 } 457 retval[j++] = 'x'; 458 retval[j++] = '\0'; 459 return retval; 460} 461 462/* 463 * Draw an ASCII-Art representing the fingerprint so human brain can 464 * profit from its built-in pattern recognition ability. 465 * This technique is called "random art" and can be found in some 466 * scientific publications like this original paper: 467 * 468 * "Hash Visualization: a New Technique to improve Real-World Security", 469 * Perrig A. and Song D., 1999, International Workshop on Cryptographic 470 * Techniques and E-Commerce (CrypTEC '99) 471 * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf 472 * 473 * The subject came up in a talk by Dan Kaminsky, too. 474 * 475 * If you see the picture is different, the key is different. 476 * If the picture looks the same, you still know nothing. 477 * 478 * The algorithm used here is a worm crawling over a discrete plane, 479 * leaving a trace (augmenting the field) everywhere it goes. 480 * Movement is taken from dgst_raw 2bit-wise. Bumping into walls 481 * makes the respective movement vector be ignored for this turn. 482 * Graphs are not unambiguous, because circles in graphs can be 483 * walked in either direction. 484 */ 485 486/* 487 * Field sizes for the random art. Have to be odd, so the starting point 488 * can be in the exact middle of the picture, and FLDBASE should be >=8 . 489 * Else pictures would be too dense, and drawing the frame would 490 * fail, too, because the key type would not fit in anymore. 491 */ 492#define FLDBASE 8 493#define FLDSIZE_Y (FLDBASE + 1) 494#define FLDSIZE_X (FLDBASE * 2 + 1) 495static char * 496key_fingerprint_randomart(u_char *dgst_raw, u_int dgst_raw_len, const Key *k) 497{ 498 /* 499 * Chars to be used after each other every time the worm 500 * intersects with itself. Matter of taste. 501 */ 502 char *augmentation_string = " .o+=*BOX@%&#/^SE"; 503 char *retval, *p; 504 u_char field[FLDSIZE_X][FLDSIZE_Y]; 505 u_int i, b; 506 int x, y; 507 size_t len = strlen(augmentation_string) - 1; 508 509 retval = xcalloc(1, (FLDSIZE_X + 3) * (FLDSIZE_Y + 2)); 510 511 /* initialize field */ 512 memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char)); 513 x = FLDSIZE_X / 2; 514 y = FLDSIZE_Y / 2; 515 516 /* process raw key */ 517 for (i = 0; i < dgst_raw_len; i++) { 518 int input; 519 /* each byte conveys four 2-bit move commands */ 520 input = dgst_raw[i]; 521 for (b = 0; b < 4; b++) { 522 /* evaluate 2 bit, rest is shifted later */ 523 x += (input & 0x1) ? 1 : -1; 524 y += (input & 0x2) ? 1 : -1; 525 526 /* assure we are still in bounds */ 527 x = MAX(x, 0); 528 y = MAX(y, 0); 529 x = MIN(x, FLDSIZE_X - 1); 530 y = MIN(y, FLDSIZE_Y - 1); 531 532 /* augment the field */ 533 if (field[x][y] < len - 2) 534 field[x][y]++; 535 input = input >> 2; 536 } 537 } 538 539 /* mark starting point and end point*/ 540 field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1; 541 field[x][y] = len; 542 543 /* fill in retval */ 544 snprintf(retval, FLDSIZE_X, "+--[%4s %4u]", key_type(k), key_size(k)); 545 p = strchr(retval, '\0'); 546 547 /* output upper border */ 548 for (i = p - retval - 1; i < FLDSIZE_X; i++) 549 *p++ = '-'; 550 *p++ = '+'; 551 *p++ = '\n'; 552 553 /* output content */ 554 for (y = 0; y < FLDSIZE_Y; y++) { 555 *p++ = '|'; 556 for (x = 0; x < FLDSIZE_X; x++) 557 *p++ = augmentation_string[MIN(field[x][y], len)]; 558 *p++ = '|'; 559 *p++ = '\n'; 560 } 561 562 /* output lower border */ 563 *p++ = '+'; 564 for (i = 0; i < FLDSIZE_X; i++) 565 *p++ = '-'; 566 *p++ = '+'; 567 568 return retval; 569} 570 571char * 572key_fingerprint(const Key *k, enum fp_type dgst_type, enum fp_rep dgst_rep) 573{ 574 char *retval = NULL; 575 u_char *dgst_raw; 576 u_int dgst_raw_len; 577 578 dgst_raw = key_fingerprint_raw(k, dgst_type, &dgst_raw_len); 579 if (!dgst_raw) 580 fatal("key_fingerprint: null from key_fingerprint_raw()"); 581 switch (dgst_rep) { 582 case SSH_FP_HEX: 583 retval = key_fingerprint_hex(dgst_raw, dgst_raw_len); 584 break; 585 case SSH_FP_BUBBLEBABBLE: 586 retval = key_fingerprint_bubblebabble(dgst_raw, dgst_raw_len); 587 break; 588 case SSH_FP_RANDOMART: 589 retval = key_fingerprint_randomart(dgst_raw, dgst_raw_len, k); 590 break; 591 default: 592 fatal("key_fingerprint: bad digest representation %d", 593 dgst_rep); 594 break; 595 } 596 memset(dgst_raw, 0, dgst_raw_len); 597 free(dgst_raw); 598 return retval; 599} 600 601/* 602 * Reads a multiple-precision integer in decimal from the buffer, and advances 603 * the pointer. The integer must already be initialized. This function is 604 * permitted to modify the buffer. This leaves *cpp to point just beyond the 605 * last processed (and maybe modified) character. Note that this may modify 606 * the buffer containing the number. 607 */ 608static int 609read_bignum(char **cpp, BIGNUM * value) 610{ 611 char *cp = *cpp; 612 int old; 613 614 /* Skip any leading whitespace. */ 615 for (; *cp == ' ' || *cp == '\t'; cp++) 616 ; 617 618 /* Check that it begins with a decimal digit. */ 619 if (*cp < '0' || *cp > '9') 620 return 0; 621 622 /* Save starting position. */ 623 *cpp = cp; 624 625 /* Move forward until all decimal digits skipped. */ 626 for (; *cp >= '0' && *cp <= '9'; cp++) 627 ; 628 629 /* Save the old terminating character, and replace it by \0. */ 630 old = *cp; 631 *cp = 0; 632 633 /* Parse the number. */ 634 if (BN_dec2bn(&value, *cpp) == 0) 635 return 0; 636 637 /* Restore old terminating character. */ 638 *cp = old; 639 640 /* Move beyond the number and return success. */ 641 *cpp = cp; 642 return 1; 643} 644 645static int 646write_bignum(FILE *f, BIGNUM *num) 647{ 648 char *buf = BN_bn2dec(num); 649 if (buf == NULL) { 650 error("write_bignum: BN_bn2dec() failed"); 651 return 0; 652 } 653 fprintf(f, " %s", buf); 654 OPENSSL_free(buf); 655 return 1; 656} 657 658/* returns 1 ok, -1 error */ 659int 660key_read(Key *ret, char **cpp) 661{ 662 Key *k; 663 int success = -1; 664 char *cp, *space; 665 int len, n, type; 666 u_int bits; 667 u_char *blob; 668#ifdef OPENSSL_HAS_ECC 669 int curve_nid = -1; 670#endif 671 672 cp = *cpp; 673 674 switch (ret->type) { 675 case KEY_RSA1: 676 /* Get number of bits. */ 677 if (*cp < '0' || *cp > '9') 678 return -1; /* Bad bit count... */ 679 for (bits = 0; *cp >= '0' && *cp <= '9'; cp++) 680 bits = 10 * bits + *cp - '0'; 681 if (bits == 0) 682 return -1; 683 *cpp = cp; 684 /* Get public exponent, public modulus. */ 685 if (!read_bignum(cpp, ret->rsa->e)) 686 return -1; 687 if (!read_bignum(cpp, ret->rsa->n)) 688 return -1; 689 /* validate the claimed number of bits */ 690 if ((u_int)BN_num_bits(ret->rsa->n) != bits) { 691 verbose("key_read: claimed key size %d does not match " 692 "actual %d", bits, BN_num_bits(ret->rsa->n)); 693 return -1; 694 } 695 success = 1; 696 break; 697 case KEY_UNSPEC: 698 case KEY_RSA: 699 case KEY_DSA: 700 case KEY_ECDSA: 701 case KEY_DSA_CERT_V00: 702 case KEY_RSA_CERT_V00: 703 case KEY_DSA_CERT: 704 case KEY_ECDSA_CERT: 705 case KEY_RSA_CERT: 706 space = strchr(cp, ' '); 707 if (space == NULL) { 708 debug3("key_read: missing whitespace"); 709 return -1; 710 } 711 *space = '\0'; 712 type = key_type_from_name(cp); 713#ifdef OPENSSL_HAS_ECC 714 if (key_type_plain(type) == KEY_ECDSA && 715 (curve_nid = key_ecdsa_nid_from_name(cp)) == -1) { 716 debug("key_read: invalid curve"); 717 return -1; 718 } 719#endif 720 *space = ' '; 721 if (type == KEY_UNSPEC) { 722 debug3("key_read: missing keytype"); 723 return -1; 724 } 725 cp = space+1; 726 if (*cp == '\0') { 727 debug3("key_read: short string"); 728 return -1; 729 } 730 if (ret->type == KEY_UNSPEC) { 731 ret->type = type; 732 } else if (ret->type != type) { 733 /* is a key, but different type */ 734 debug3("key_read: type mismatch"); 735 return -1; 736 } 737 len = 2*strlen(cp); 738 blob = xmalloc(len); 739 n = uudecode(cp, blob, len); 740 if (n < 0) { 741 error("key_read: uudecode %s failed", cp); 742 free(blob); 743 return -1; 744 } 745 k = key_from_blob(blob, (u_int)n); 746 free(blob); 747 if (k == NULL) { 748 error("key_read: key_from_blob %s failed", cp); 749 return -1; 750 } 751 if (k->type != type) { 752 error("key_read: type mismatch: encoding error"); 753 key_free(k); 754 return -1; 755 } 756#ifdef OPENSSL_HAS_ECC 757 if (key_type_plain(type) == KEY_ECDSA && 758 curve_nid != k->ecdsa_nid) { 759 error("key_read: type mismatch: EC curve mismatch"); 760 key_free(k); 761 return -1; 762 } 763#endif 764/*XXXX*/ 765 if (key_is_cert(ret)) { 766 if (!key_is_cert(k)) { 767 error("key_read: loaded key is not a cert"); 768 key_free(k); 769 return -1; 770 } 771 if (ret->cert != NULL) 772 cert_free(ret->cert); 773 ret->cert = k->cert; 774 k->cert = NULL; 775 } 776 if (key_type_plain(ret->type) == KEY_RSA) { 777 if (ret->rsa != NULL) 778 RSA_free(ret->rsa); 779 ret->rsa = k->rsa; 780 k->rsa = NULL; 781#ifdef DEBUG_PK 782 RSA_print_fp(stderr, ret->rsa, 8); 783#endif 784 } 785 if (key_type_plain(ret->type) == KEY_DSA) { 786 if (ret->dsa != NULL) 787 DSA_free(ret->dsa); 788 ret->dsa = k->dsa; 789 k->dsa = NULL; 790#ifdef DEBUG_PK 791 DSA_print_fp(stderr, ret->dsa, 8); 792#endif 793 } 794#ifdef OPENSSL_HAS_ECC 795 if (key_type_plain(ret->type) == KEY_ECDSA) { 796 if (ret->ecdsa != NULL) 797 EC_KEY_free(ret->ecdsa); 798 ret->ecdsa = k->ecdsa; 799 ret->ecdsa_nid = k->ecdsa_nid; 800 k->ecdsa = NULL; 801 k->ecdsa_nid = -1; 802#ifdef DEBUG_PK 803 key_dump_ec_key(ret->ecdsa); 804#endif 805 } 806#endif 807 success = 1; 808/*XXXX*/ 809 key_free(k); 810 if (success != 1) 811 break; 812 /* advance cp: skip whitespace and data */ 813 while (*cp == ' ' || *cp == '\t') 814 cp++; 815 while (*cp != '\0' && *cp != ' ' && *cp != '\t') 816 cp++; 817 *cpp = cp; 818 break; 819 default: 820 fatal("key_read: bad key type: %d", ret->type); 821 break; 822 } 823 return success; 824} 825 826int 827key_write(const Key *key, FILE *f) 828{ 829 int n, success = 0; 830 u_int len, bits = 0; 831 u_char *blob; 832 char *uu; 833 834 if (key_is_cert(key)) { 835 if (key->cert == NULL) { 836 error("%s: no cert data", __func__); 837 return 0; 838 } 839 if (buffer_len(&key->cert->certblob) == 0) { 840 error("%s: no signed certificate blob", __func__); 841 return 0; 842 } 843 } 844 845 switch (key->type) { 846 case KEY_RSA1: 847 if (key->rsa == NULL) 848 return 0; 849 /* size of modulus 'n' */ 850 bits = BN_num_bits(key->rsa->n); 851 fprintf(f, "%u", bits); 852 if (write_bignum(f, key->rsa->e) && 853 write_bignum(f, key->rsa->n)) 854 return 1; 855 error("key_write: failed for RSA key"); 856 return 0; 857 case KEY_DSA: 858 case KEY_DSA_CERT_V00: 859 case KEY_DSA_CERT: 860 if (key->dsa == NULL) 861 return 0; 862 break; 863#ifdef OPENSSL_HAS_ECC 864 case KEY_ECDSA: 865 case KEY_ECDSA_CERT: 866 if (key->ecdsa == NULL) 867 return 0; 868 break; 869#endif 870 case KEY_RSA: 871 case KEY_RSA_CERT_V00: 872 case KEY_RSA_CERT: 873 if (key->rsa == NULL) 874 return 0; 875 break; 876 default: 877 return 0; 878 } 879 880 key_to_blob(key, &blob, &len); 881 uu = xmalloc(2*len); 882 n = uuencode(blob, len, uu, 2*len); 883 if (n > 0) { 884 fprintf(f, "%s %s", key_ssh_name(key), uu); 885 success = 1; 886 } 887 free(blob); 888 free(uu); 889 890 return success; 891} 892 893const char * 894key_cert_type(const Key *k) 895{ 896 switch (k->cert->type) { 897 case SSH2_CERT_TYPE_USER: 898 return "user"; 899 case SSH2_CERT_TYPE_HOST: 900 return "host"; 901 default: 902 return "unknown"; 903 } 904} 905 906struct keytype { 907 char *name; 908 char *shortname; 909 int type; 910 int nid; 911 int cert; 912}; 913static const struct keytype keytypes[] = { 914 { NULL, "RSA1", KEY_RSA1, 0, 0 }, 915 { "ssh-rsa", "RSA", KEY_RSA, 0, 0 }, 916 { "ssh-dss", "DSA", KEY_DSA, 0, 0 }, 917#ifdef OPENSSL_HAS_ECC 918 { "ecdsa-sha2-nistp256", "ECDSA", KEY_ECDSA, NID_X9_62_prime256v1, 0 }, 919 { "ecdsa-sha2-nistp384", "ECDSA", KEY_ECDSA, NID_secp384r1, 0 }, 920 { "ecdsa-sha2-nistp521", "ECDSA", KEY_ECDSA, NID_secp521r1, 0 }, 921#endif /* OPENSSL_HAS_ECC */ 922 { "ssh-rsa-cert-v01@openssh.com", "RSA-CERT", KEY_RSA_CERT, 0, 1 }, 923 { "ssh-dss-cert-v01@openssh.com", "DSA-CERT", KEY_DSA_CERT, 0, 1 }, 924#ifdef OPENSSL_HAS_ECC 925 { "ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-CERT", 926 KEY_ECDSA_CERT, NID_X9_62_prime256v1, 1 }, 927 { "ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA-CERT", 928 KEY_ECDSA_CERT, NID_secp384r1, 1 }, 929 { "ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA-CERT", 930 KEY_ECDSA_CERT, NID_secp521r1, 1 }, 931#endif /* OPENSSL_HAS_ECC */ 932 { "ssh-rsa-cert-v00@openssh.com", "RSA-CERT-V00", 933 KEY_RSA_CERT_V00, 0, 1 }, 934 { "ssh-dss-cert-v00@openssh.com", "DSA-CERT-V00", 935 KEY_DSA_CERT_V00, 0, 1 }, 936 { NULL, NULL, -1, -1, 0 } 937}; 938 939const char * 940key_type(const Key *k) 941{ 942 const struct keytype *kt; 943 944 for (kt = keytypes; kt->type != -1; kt++) { 945 if (kt->type == k->type) 946 return kt->shortname; 947 } 948 return "unknown"; 949} 950 951static const char * 952key_ssh_name_from_type_nid(int type, int nid) 953{ 954 const struct keytype *kt; 955 956 for (kt = keytypes; kt->type != -1; kt++) { 957 if (kt->type == type && (kt->nid == 0 || kt->nid == nid)) 958 return kt->name; 959 } 960 return "ssh-unknown"; 961} 962 963const char * 964key_ssh_name(const Key *k) 965{ 966 return key_ssh_name_from_type_nid(k->type, k->ecdsa_nid); 967} 968 969const char * 970key_ssh_name_plain(const Key *k) 971{ 972 return key_ssh_name_from_type_nid(key_type_plain(k->type), 973 k->ecdsa_nid); 974} 975 976int 977key_type_from_name(char *name) 978{ 979 const struct keytype *kt; 980 981 for (kt = keytypes; kt->type != -1; kt++) { 982 /* Only allow shortname matches for plain key types */ 983 if ((kt->name != NULL && strcmp(name, kt->name) == 0) || 984 (!kt->cert && strcasecmp(kt->shortname, name) == 0)) 985 return kt->type; 986 } 987 debug2("key_type_from_name: unknown key type '%s'", name); 988 return KEY_UNSPEC; 989} 990 991int 992key_ecdsa_nid_from_name(const char *name) 993{ 994 const struct keytype *kt; 995 996 for (kt = keytypes; kt->type != -1; kt++) { 997 if (kt->type != KEY_ECDSA && kt->type != KEY_ECDSA_CERT) 998 continue; 999 if (kt->name != NULL && strcmp(name, kt->name) == 0) 1000 return kt->nid; 1001 } 1002 debug2("%s: unknown/non-ECDSA key type '%s'", __func__, name); 1003 return -1; 1004} 1005 1006char * 1007key_alg_list(void) 1008{ 1009 char *ret = NULL; 1010 size_t nlen, rlen = 0; 1011 const struct keytype *kt; 1012 1013 for (kt = keytypes; kt->type != -1; kt++) { 1014 if (kt->name == NULL) 1015 continue; 1016 if (ret != NULL) 1017 ret[rlen++] = '\n'; 1018 nlen = strlen(kt->name); 1019 ret = xrealloc(ret, 1, rlen + nlen + 2); 1020 memcpy(ret + rlen, kt->name, nlen + 1); 1021 rlen += nlen; 1022 } 1023 return ret; 1024} 1025 1026u_int 1027key_size(const Key *k) 1028{ 1029 switch (k->type) { 1030 case KEY_RSA1: 1031 case KEY_RSA: 1032 case KEY_RSA_CERT_V00: 1033 case KEY_RSA_CERT: 1034 return BN_num_bits(k->rsa->n); 1035 case KEY_DSA: 1036 case KEY_DSA_CERT_V00: 1037 case KEY_DSA_CERT: 1038 return BN_num_bits(k->dsa->p); 1039#ifdef OPENSSL_HAS_ECC 1040 case KEY_ECDSA: 1041 case KEY_ECDSA_CERT: 1042 return key_curve_nid_to_bits(k->ecdsa_nid); 1043#endif 1044 } 1045 return 0; 1046} 1047 1048static RSA * 1049rsa_generate_private_key(u_int bits) 1050{ 1051 RSA *private = RSA_new(); 1052 BIGNUM *f4 = BN_new(); 1053 1054 if (private == NULL) 1055 fatal("%s: RSA_new failed", __func__); 1056 if (f4 == NULL) 1057 fatal("%s: BN_new failed", __func__); 1058 if (!BN_set_word(f4, RSA_F4)) 1059 fatal("%s: BN_new failed", __func__); 1060 if (!RSA_generate_key_ex(private, bits, f4, NULL)) 1061 fatal("%s: key generation failed.", __func__); 1062 BN_free(f4); 1063 return private; 1064} 1065 1066static DSA* 1067dsa_generate_private_key(u_int bits) 1068{ 1069 DSA *private = DSA_new(); 1070 1071 if (private == NULL) 1072 fatal("%s: DSA_new failed", __func__); 1073 if (!DSA_generate_parameters_ex(private, bits, NULL, 0, NULL, 1074 NULL, NULL)) 1075 fatal("%s: DSA_generate_parameters failed", __func__); 1076 if (!DSA_generate_key(private)) 1077 fatal("%s: DSA_generate_key failed.", __func__); 1078 return private; 1079} 1080 1081int 1082key_ecdsa_bits_to_nid(int bits) 1083{ 1084 switch (bits) { 1085#ifdef OPENSSL_HAS_ECC 1086 case 256: 1087 return NID_X9_62_prime256v1; 1088 case 384: 1089 return NID_secp384r1; 1090 case 521: 1091 return NID_secp521r1; 1092#endif 1093 default: 1094 return -1; 1095 } 1096} 1097 1098#ifdef OPENSSL_HAS_ECC 1099int 1100key_ecdsa_key_to_nid(EC_KEY *k) 1101{ 1102 EC_GROUP *eg; 1103 int nids[] = { 1104 NID_X9_62_prime256v1, 1105 NID_secp384r1, 1106 NID_secp521r1, 1107 -1 1108 }; 1109 int nid; 1110 u_int i; 1111 BN_CTX *bnctx; 1112 const EC_GROUP *g = EC_KEY_get0_group(k); 1113 1114 /* 1115 * The group may be stored in a ASN.1 encoded private key in one of two 1116 * ways: as a "named group", which is reconstituted by ASN.1 object ID 1117 * or explicit group parameters encoded into the key blob. Only the 1118 * "named group" case sets the group NID for us, but we can figure 1119 * it out for the other case by comparing against all the groups that 1120 * are supported. 1121 */ 1122 if ((nid = EC_GROUP_get_curve_name(g)) > 0) 1123 return nid; 1124 if ((bnctx = BN_CTX_new()) == NULL) 1125 fatal("%s: BN_CTX_new() failed", __func__); 1126 for (i = 0; nids[i] != -1; i++) { 1127 if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL) 1128 fatal("%s: EC_GROUP_new_by_curve_name failed", 1129 __func__); 1130 if (EC_GROUP_cmp(g, eg, bnctx) == 0) 1131 break; 1132 EC_GROUP_free(eg); 1133 } 1134 BN_CTX_free(bnctx); 1135 debug3("%s: nid = %d", __func__, nids[i]); 1136 if (nids[i] != -1) { 1137 /* Use the group with the NID attached */ 1138 EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE); 1139 if (EC_KEY_set_group(k, eg) != 1) 1140 fatal("%s: EC_KEY_set_group", __func__); 1141 } 1142 return nids[i]; 1143} 1144 1145static EC_KEY* 1146ecdsa_generate_private_key(u_int bits, int *nid) 1147{ 1148 EC_KEY *private; 1149 1150 if ((*nid = key_ecdsa_bits_to_nid(bits)) == -1) 1151 fatal("%s: invalid key length", __func__); 1152 if ((private = EC_KEY_new_by_curve_name(*nid)) == NULL) 1153 fatal("%s: EC_KEY_new_by_curve_name failed", __func__); 1154 if (EC_KEY_generate_key(private) != 1) 1155 fatal("%s: EC_KEY_generate_key failed", __func__); 1156 EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE); 1157 return private; 1158} 1159#endif /* OPENSSL_HAS_ECC */ 1160 1161Key * 1162key_generate(int type, u_int bits) 1163{ 1164 Key *k = key_new(KEY_UNSPEC); 1165 switch (type) { 1166 case KEY_DSA: 1167 k->dsa = dsa_generate_private_key(bits); 1168 break; 1169#ifdef OPENSSL_HAS_ECC 1170 case KEY_ECDSA: 1171 k->ecdsa = ecdsa_generate_private_key(bits, &k->ecdsa_nid); 1172 break; 1173#endif 1174 case KEY_RSA: 1175 case KEY_RSA1: 1176 k->rsa = rsa_generate_private_key(bits); 1177 break; 1178 case KEY_RSA_CERT_V00: 1179 case KEY_DSA_CERT_V00: 1180 case KEY_RSA_CERT: 1181 case KEY_DSA_CERT: 1182 fatal("key_generate: cert keys cannot be generated directly"); 1183 default: 1184 fatal("key_generate: unknown type %d", type); 1185 } 1186 k->type = type; 1187 return k; 1188} 1189 1190void 1191key_cert_copy(const Key *from_key, struct Key *to_key) 1192{ 1193 u_int i; 1194 const struct KeyCert *from; 1195 struct KeyCert *to; 1196 1197 if (to_key->cert != NULL) { 1198 cert_free(to_key->cert); 1199 to_key->cert = NULL; 1200 } 1201 1202 if ((from = from_key->cert) == NULL) 1203 return; 1204 1205 to = to_key->cert = cert_new(); 1206 1207 buffer_append(&to->certblob, buffer_ptr(&from->certblob), 1208 buffer_len(&from->certblob)); 1209 1210 buffer_append(&to->critical, 1211 buffer_ptr(&from->critical), buffer_len(&from->critical)); 1212 buffer_append(&to->extensions, 1213 buffer_ptr(&from->extensions), buffer_len(&from->extensions)); 1214 1215 to->serial = from->serial; 1216 to->type = from->type; 1217 to->key_id = from->key_id == NULL ? NULL : xstrdup(from->key_id); 1218 to->valid_after = from->valid_after; 1219 to->valid_before = from->valid_before; 1220 to->signature_key = from->signature_key == NULL ? 1221 NULL : key_from_private(from->signature_key); 1222 1223 to->nprincipals = from->nprincipals; 1224 if (to->nprincipals > CERT_MAX_PRINCIPALS) 1225 fatal("%s: nprincipals (%u) > CERT_MAX_PRINCIPALS (%u)", 1226 __func__, to->nprincipals, CERT_MAX_PRINCIPALS); 1227 if (to->nprincipals > 0) { 1228 to->principals = xcalloc(from->nprincipals, 1229 sizeof(*to->principals)); 1230 for (i = 0; i < to->nprincipals; i++) 1231 to->principals[i] = xstrdup(from->principals[i]); 1232 } 1233} 1234 1235Key * 1236key_from_private(const Key *k) 1237{ 1238 Key *n = NULL; 1239 switch (k->type) { 1240 case KEY_DSA: 1241 case KEY_DSA_CERT_V00: 1242 case KEY_DSA_CERT: 1243 n = key_new(k->type); 1244 if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) || 1245 (BN_copy(n->dsa->q, k->dsa->q) == NULL) || 1246 (BN_copy(n->dsa->g, k->dsa->g) == NULL) || 1247 (BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL)) 1248 fatal("key_from_private: BN_copy failed"); 1249 break; 1250#ifdef OPENSSL_HAS_ECC 1251 case KEY_ECDSA: 1252 case KEY_ECDSA_CERT: 1253 n = key_new(k->type); 1254 n->ecdsa_nid = k->ecdsa_nid; 1255 if ((n->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid)) == NULL) 1256 fatal("%s: EC_KEY_new_by_curve_name failed", __func__); 1257 if (EC_KEY_set_public_key(n->ecdsa, 1258 EC_KEY_get0_public_key(k->ecdsa)) != 1) 1259 fatal("%s: EC_KEY_set_public_key failed", __func__); 1260 break; 1261#endif 1262 case KEY_RSA: 1263 case KEY_RSA1: 1264 case KEY_RSA_CERT_V00: 1265 case KEY_RSA_CERT: 1266 n = key_new(k->type); 1267 if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) || 1268 (BN_copy(n->rsa->e, k->rsa->e) == NULL)) 1269 fatal("key_from_private: BN_copy failed"); 1270 break; 1271 default: 1272 fatal("key_from_private: unknown type %d", k->type); 1273 break; 1274 } 1275 if (key_is_cert(k)) 1276 key_cert_copy(k, n); 1277 return n; 1278} 1279 1280int 1281key_names_valid2(const char *names) 1282{ 1283 char *s, *cp, *p; 1284 1285 if (names == NULL || strcmp(names, "") == 0) 1286 return 0; 1287 s = cp = xstrdup(names); 1288 for ((p = strsep(&cp, ",")); p && *p != '\0'; 1289 (p = strsep(&cp, ","))) { 1290 switch (key_type_from_name(p)) { 1291 case KEY_RSA1: 1292 case KEY_UNSPEC: 1293 free(s); 1294 return 0; 1295 } 1296 } 1297 debug3("key names ok: [%s]", names); 1298 free(s); 1299 return 1; 1300} 1301 1302static int 1303cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen) 1304{ 1305 u_char *principals, *critical, *exts, *sig_key, *sig; 1306 u_int signed_len, plen, clen, sklen, slen, kidlen, elen; 1307 Buffer tmp; 1308 char *principal; 1309 int ret = -1; 1310 int v00 = key->type == KEY_DSA_CERT_V00 || 1311 key->type == KEY_RSA_CERT_V00; 1312 1313 buffer_init(&tmp); 1314 1315 /* Copy the entire key blob for verification and later serialisation */ 1316 buffer_append(&key->cert->certblob, blob, blen); 1317 1318 elen = 0; /* Not touched for v00 certs */ 1319 principals = exts = critical = sig_key = sig = NULL; 1320 if ((!v00 && buffer_get_int64_ret(&key->cert->serial, b) != 0) || 1321 buffer_get_int_ret(&key->cert->type, b) != 0 || 1322 (key->cert->key_id = buffer_get_cstring_ret(b, &kidlen)) == NULL || 1323 (principals = buffer_get_string_ret(b, &plen)) == NULL || 1324 buffer_get_int64_ret(&key->cert->valid_after, b) != 0 || 1325 buffer_get_int64_ret(&key->cert->valid_before, b) != 0 || 1326 (critical = buffer_get_string_ret(b, &clen)) == NULL || 1327 (!v00 && (exts = buffer_get_string_ret(b, &elen)) == NULL) || 1328 (v00 && buffer_get_string_ptr_ret(b, NULL) == NULL) || /* nonce */ 1329 buffer_get_string_ptr_ret(b, NULL) == NULL || /* reserved */ 1330 (sig_key = buffer_get_string_ret(b, &sklen)) == NULL) { 1331 error("%s: parse error", __func__); 1332 goto out; 1333 } 1334 1335 /* Signature is left in the buffer so we can calculate this length */ 1336 signed_len = buffer_len(&key->cert->certblob) - buffer_len(b); 1337 1338 if ((sig = buffer_get_string_ret(b, &slen)) == NULL) { 1339 error("%s: parse error", __func__); 1340 goto out; 1341 } 1342 1343 if (key->cert->type != SSH2_CERT_TYPE_USER && 1344 key->cert->type != SSH2_CERT_TYPE_HOST) { 1345 error("Unknown certificate type %u", key->cert->type); 1346 goto out; 1347 } 1348 1349 buffer_append(&tmp, principals, plen); 1350 while (buffer_len(&tmp) > 0) { 1351 if (key->cert->nprincipals >= CERT_MAX_PRINCIPALS) { 1352 error("%s: Too many principals", __func__); 1353 goto out; 1354 } 1355 if ((principal = buffer_get_cstring_ret(&tmp, &plen)) == NULL) { 1356 error("%s: Principals data invalid", __func__); 1357 goto out; 1358 } 1359 key->cert->principals = xrealloc(key->cert->principals, 1360 key->cert->nprincipals + 1, sizeof(*key->cert->principals)); 1361 key->cert->principals[key->cert->nprincipals++] = principal; 1362 } 1363 1364 buffer_clear(&tmp); 1365 1366 buffer_append(&key->cert->critical, critical, clen); 1367 buffer_append(&tmp, critical, clen); 1368 /* validate structure */ 1369 while (buffer_len(&tmp) != 0) { 1370 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL || 1371 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) { 1372 error("%s: critical option data invalid", __func__); 1373 goto out; 1374 } 1375 } 1376 buffer_clear(&tmp); 1377 1378 buffer_append(&key->cert->extensions, exts, elen); 1379 buffer_append(&tmp, exts, elen); 1380 /* validate structure */ 1381 while (buffer_len(&tmp) != 0) { 1382 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL || 1383 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) { 1384 error("%s: extension data invalid", __func__); 1385 goto out; 1386 } 1387 } 1388 buffer_clear(&tmp); 1389 1390 if ((key->cert->signature_key = key_from_blob(sig_key, 1391 sklen)) == NULL) { 1392 error("%s: Signature key invalid", __func__); 1393 goto out; 1394 } 1395 if (key->cert->signature_key->type != KEY_RSA && 1396 key->cert->signature_key->type != KEY_DSA && 1397 key->cert->signature_key->type != KEY_ECDSA) { 1398 error("%s: Invalid signature key type %s (%d)", __func__, 1399 key_type(key->cert->signature_key), 1400 key->cert->signature_key->type); 1401 goto out; 1402 } 1403 1404 switch (key_verify(key->cert->signature_key, sig, slen, 1405 buffer_ptr(&key->cert->certblob), signed_len)) { 1406 case 1: 1407 ret = 0; 1408 break; /* Good signature */ 1409 case 0: 1410 error("%s: Invalid signature on certificate", __func__); 1411 goto out; 1412 case -1: 1413 error("%s: Certificate signature verification failed", 1414 __func__); 1415 goto out; 1416 } 1417 1418 out: 1419 buffer_free(&tmp); 1420 free(principals); 1421 free(critical); 1422 free(exts); 1423 free(sig_key); 1424 free(sig); 1425 return ret; 1426} 1427 1428Key * 1429key_from_blob(const u_char *blob, u_int blen) 1430{ 1431 Buffer b; 1432 int rlen, type; 1433 char *ktype = NULL, *curve = NULL; 1434 Key *key = NULL; 1435#ifdef OPENSSL_HAS_ECC 1436 EC_POINT *q = NULL; 1437 int nid = -1; 1438#endif 1439 1440#ifdef DEBUG_PK 1441 dump_base64(stderr, blob, blen); 1442#endif 1443 buffer_init(&b); 1444 buffer_append(&b, blob, blen); 1445 if ((ktype = buffer_get_cstring_ret(&b, NULL)) == NULL) { 1446 error("key_from_blob: can't read key type"); 1447 goto out; 1448 } 1449 1450 type = key_type_from_name(ktype); 1451#ifdef OPENSSL_HAS_ECC 1452 if (key_type_plain(type) == KEY_ECDSA) 1453 nid = key_ecdsa_nid_from_name(ktype); 1454#endif 1455 1456 switch (type) { 1457 case KEY_RSA_CERT: 1458 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */ 1459 /* FALLTHROUGH */ 1460 case KEY_RSA: 1461 case KEY_RSA_CERT_V00: 1462 key = key_new(type); 1463 if (buffer_get_bignum2_ret(&b, key->rsa->e) == -1 || 1464 buffer_get_bignum2_ret(&b, key->rsa->n) == -1) { 1465 error("key_from_blob: can't read rsa key"); 1466 badkey: 1467 key_free(key); 1468 key = NULL; 1469 goto out; 1470 } 1471#ifdef DEBUG_PK 1472 RSA_print_fp(stderr, key->rsa, 8); 1473#endif 1474 break; 1475 case KEY_DSA_CERT: 1476 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */ 1477 /* FALLTHROUGH */ 1478 case KEY_DSA: 1479 case KEY_DSA_CERT_V00: 1480 key = key_new(type); 1481 if (buffer_get_bignum2_ret(&b, key->dsa->p) == -1 || 1482 buffer_get_bignum2_ret(&b, key->dsa->q) == -1 || 1483 buffer_get_bignum2_ret(&b, key->dsa->g) == -1 || 1484 buffer_get_bignum2_ret(&b, key->dsa->pub_key) == -1) { 1485 error("key_from_blob: can't read dsa key"); 1486 goto badkey; 1487 } 1488#ifdef DEBUG_PK 1489 DSA_print_fp(stderr, key->dsa, 8); 1490#endif 1491 break; 1492#ifdef OPENSSL_HAS_ECC 1493 case KEY_ECDSA_CERT: 1494 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */ 1495 /* FALLTHROUGH */ 1496 case KEY_ECDSA: 1497 key = key_new(type); 1498 key->ecdsa_nid = nid; 1499 if ((curve = buffer_get_string_ret(&b, NULL)) == NULL) { 1500 error("key_from_blob: can't read ecdsa curve"); 1501 goto badkey; 1502 } 1503 if (key->ecdsa_nid != key_curve_name_to_nid(curve)) { 1504 error("key_from_blob: ecdsa curve doesn't match type"); 1505 goto badkey; 1506 } 1507 if (key->ecdsa != NULL) 1508 EC_KEY_free(key->ecdsa); 1509 if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid)) 1510 == NULL) 1511 fatal("key_from_blob: EC_KEY_new_by_curve_name failed"); 1512 if ((q = EC_POINT_new(EC_KEY_get0_group(key->ecdsa))) == NULL) 1513 fatal("key_from_blob: EC_POINT_new failed"); 1514 if (buffer_get_ecpoint_ret(&b, EC_KEY_get0_group(key->ecdsa), 1515 q) == -1) { 1516 error("key_from_blob: can't read ecdsa key point"); 1517 goto badkey; 1518 } 1519 if (key_ec_validate_public(EC_KEY_get0_group(key->ecdsa), 1520 q) != 0) 1521 goto badkey; 1522 if (EC_KEY_set_public_key(key->ecdsa, q) != 1) 1523 fatal("key_from_blob: EC_KEY_set_public_key failed"); 1524#ifdef DEBUG_PK 1525 key_dump_ec_point(EC_KEY_get0_group(key->ecdsa), q); 1526#endif 1527 break; 1528#endif /* OPENSSL_HAS_ECC */ 1529 case KEY_UNSPEC: 1530 key = key_new(type); 1531 break; 1532 default: 1533 error("key_from_blob: cannot handle type %s", ktype); 1534 goto out; 1535 } 1536 if (key_is_cert(key) && cert_parse(&b, key, blob, blen) == -1) { 1537 error("key_from_blob: can't parse cert data"); 1538 goto badkey; 1539 } 1540 rlen = buffer_len(&b); 1541 if (key != NULL && rlen != 0) 1542 error("key_from_blob: remaining bytes in key blob %d", rlen); 1543 out: 1544 free(ktype); 1545 free(curve); 1546#ifdef OPENSSL_HAS_ECC 1547 if (q != NULL) 1548 EC_POINT_free(q); 1549#endif 1550 buffer_free(&b); 1551 return key; 1552} 1553 1554static int 1555to_blob(const Key *key, u_char **blobp, u_int *lenp, int force_plain) 1556{ 1557 Buffer b; 1558 int len, type; 1559 1560 if (key == NULL) { 1561 error("key_to_blob: key == NULL"); 1562 return 0; 1563 } 1564 buffer_init(&b); 1565 type = force_plain ? key_type_plain(key->type) : key->type; 1566 switch (type) { 1567 case KEY_DSA_CERT_V00: 1568 case KEY_RSA_CERT_V00: 1569 case KEY_DSA_CERT: 1570 case KEY_ECDSA_CERT: 1571 case KEY_RSA_CERT: 1572 /* Use the existing blob */ 1573 buffer_append(&b, buffer_ptr(&key->cert->certblob), 1574 buffer_len(&key->cert->certblob)); 1575 break; 1576 case KEY_DSA: 1577 buffer_put_cstring(&b, 1578 key_ssh_name_from_type_nid(type, key->ecdsa_nid)); 1579 buffer_put_bignum2(&b, key->dsa->p); 1580 buffer_put_bignum2(&b, key->dsa->q); 1581 buffer_put_bignum2(&b, key->dsa->g); 1582 buffer_put_bignum2(&b, key->dsa->pub_key); 1583 break; 1584#ifdef OPENSSL_HAS_ECC 1585 case KEY_ECDSA: 1586 buffer_put_cstring(&b, 1587 key_ssh_name_from_type_nid(type, key->ecdsa_nid)); 1588 buffer_put_cstring(&b, key_curve_nid_to_name(key->ecdsa_nid)); 1589 buffer_put_ecpoint(&b, EC_KEY_get0_group(key->ecdsa), 1590 EC_KEY_get0_public_key(key->ecdsa)); 1591 break; 1592#endif 1593 case KEY_RSA: 1594 buffer_put_cstring(&b, 1595 key_ssh_name_from_type_nid(type, key->ecdsa_nid)); 1596 buffer_put_bignum2(&b, key->rsa->e); 1597 buffer_put_bignum2(&b, key->rsa->n); 1598 break; 1599 default: 1600 error("key_to_blob: unsupported key type %d", key->type); 1601 buffer_free(&b); 1602 return 0; 1603 } 1604 len = buffer_len(&b); 1605 if (lenp != NULL) 1606 *lenp = len; 1607 if (blobp != NULL) { 1608 *blobp = xmalloc(len); 1609 memcpy(*blobp, buffer_ptr(&b), len); 1610 } 1611 memset(buffer_ptr(&b), 0, len); 1612 buffer_free(&b); 1613 return len; 1614} 1615 1616int 1617key_to_blob(const Key *key, u_char **blobp, u_int *lenp) 1618{ 1619 return to_blob(key, blobp, lenp, 0); 1620} 1621 1622int 1623key_sign( 1624 const Key *key, 1625 u_char **sigp, u_int *lenp, 1626 const u_char *data, u_int datalen) 1627{ 1628 switch (key->type) { 1629 case KEY_DSA_CERT_V00: 1630 case KEY_DSA_CERT: 1631 case KEY_DSA: 1632 return ssh_dss_sign(key, sigp, lenp, data, datalen); 1633#ifdef OPENSSL_HAS_ECC 1634 case KEY_ECDSA_CERT: 1635 case KEY_ECDSA: 1636 return ssh_ecdsa_sign(key, sigp, lenp, data, datalen); 1637#endif 1638 case KEY_RSA_CERT_V00: 1639 case KEY_RSA_CERT: 1640 case KEY_RSA: 1641 return ssh_rsa_sign(key, sigp, lenp, data, datalen); 1642 default: 1643 error("key_sign: invalid key type %d", key->type); 1644 return -1; 1645 } 1646} 1647 1648/* 1649 * key_verify returns 1 for a correct signature, 0 for an incorrect signature 1650 * and -1 on error. 1651 */ 1652int 1653key_verify( 1654 const Key *key, 1655 const u_char *signature, u_int signaturelen, 1656 const u_char *data, u_int datalen) 1657{ 1658 if (signaturelen == 0) 1659 return -1; 1660 1661 switch (key->type) { 1662 case KEY_DSA_CERT_V00: 1663 case KEY_DSA_CERT: 1664 case KEY_DSA: 1665 return ssh_dss_verify(key, signature, signaturelen, data, datalen); 1666#ifdef OPENSSL_HAS_ECC 1667 case KEY_ECDSA_CERT: 1668 case KEY_ECDSA: 1669 return ssh_ecdsa_verify(key, signature, signaturelen, data, datalen); 1670#endif 1671 case KEY_RSA_CERT_V00: 1672 case KEY_RSA_CERT: 1673 case KEY_RSA: 1674 return ssh_rsa_verify(key, signature, signaturelen, data, datalen); 1675 default: 1676 error("key_verify: invalid key type %d", key->type); 1677 return -1; 1678 } 1679} 1680 1681/* Converts a private to a public key */ 1682Key * 1683key_demote(const Key *k) 1684{ 1685 Key *pk; 1686 1687 pk = xcalloc(1, sizeof(*pk)); 1688 pk->type = k->type; 1689 pk->flags = k->flags; 1690 pk->ecdsa_nid = k->ecdsa_nid; 1691 pk->dsa = NULL; 1692 pk->ecdsa = NULL; 1693 pk->rsa = NULL; 1694 1695 switch (k->type) { 1696 case KEY_RSA_CERT_V00: 1697 case KEY_RSA_CERT: 1698 key_cert_copy(k, pk); 1699 /* FALLTHROUGH */ 1700 case KEY_RSA1: 1701 case KEY_RSA: 1702 if ((pk->rsa = RSA_new()) == NULL) 1703 fatal("key_demote: RSA_new failed"); 1704 if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL) 1705 fatal("key_demote: BN_dup failed"); 1706 if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL) 1707 fatal("key_demote: BN_dup failed"); 1708 break; 1709 case KEY_DSA_CERT_V00: 1710 case KEY_DSA_CERT: 1711 key_cert_copy(k, pk); 1712 /* FALLTHROUGH */ 1713 case KEY_DSA: 1714 if ((pk->dsa = DSA_new()) == NULL) 1715 fatal("key_demote: DSA_new failed"); 1716 if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL) 1717 fatal("key_demote: BN_dup failed"); 1718 if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL) 1719 fatal("key_demote: BN_dup failed"); 1720 if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL) 1721 fatal("key_demote: BN_dup failed"); 1722 if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL) 1723 fatal("key_demote: BN_dup failed"); 1724 break; 1725#ifdef OPENSSL_HAS_ECC 1726 case KEY_ECDSA_CERT: 1727 key_cert_copy(k, pk); 1728 /* FALLTHROUGH */ 1729 case KEY_ECDSA: 1730 if ((pk->ecdsa = EC_KEY_new_by_curve_name(pk->ecdsa_nid)) == NULL) 1731 fatal("key_demote: EC_KEY_new_by_curve_name failed"); 1732 if (EC_KEY_set_public_key(pk->ecdsa, 1733 EC_KEY_get0_public_key(k->ecdsa)) != 1) 1734 fatal("key_demote: EC_KEY_set_public_key failed"); 1735 break; 1736#endif 1737 default: 1738 fatal("key_free: bad key type %d", k->type); 1739 break; 1740 } 1741 1742 return (pk); 1743} 1744 1745int 1746key_is_cert(const Key *k) 1747{ 1748 if (k == NULL) 1749 return 0; 1750 switch (k->type) { 1751 case KEY_RSA_CERT_V00: 1752 case KEY_DSA_CERT_V00: 1753 case KEY_RSA_CERT: 1754 case KEY_DSA_CERT: 1755 case KEY_ECDSA_CERT: 1756 return 1; 1757 default: 1758 return 0; 1759 } 1760} 1761 1762/* Return the cert-less equivalent to a certified key type */ 1763int 1764key_type_plain(int type) 1765{ 1766 switch (type) { 1767 case KEY_RSA_CERT_V00: 1768 case KEY_RSA_CERT: 1769 return KEY_RSA; 1770 case KEY_DSA_CERT_V00: 1771 case KEY_DSA_CERT: 1772 return KEY_DSA; 1773 case KEY_ECDSA_CERT: 1774 return KEY_ECDSA; 1775 default: 1776 return type; 1777 } 1778} 1779 1780/* Convert a KEY_RSA or KEY_DSA to their _CERT equivalent */ 1781int 1782key_to_certified(Key *k, int legacy) 1783{ 1784 switch (k->type) { 1785 case KEY_RSA: 1786 k->cert = cert_new(); 1787 k->type = legacy ? KEY_RSA_CERT_V00 : KEY_RSA_CERT; 1788 return 0; 1789 case KEY_DSA: 1790 k->cert = cert_new(); 1791 k->type = legacy ? KEY_DSA_CERT_V00 : KEY_DSA_CERT; 1792 return 0; 1793 case KEY_ECDSA: 1794 if (legacy) 1795 fatal("%s: legacy ECDSA certificates are not supported", 1796 __func__); 1797 k->cert = cert_new(); 1798 k->type = KEY_ECDSA_CERT; 1799 return 0; 1800 default: 1801 error("%s: key has incorrect type %s", __func__, key_type(k)); 1802 return -1; 1803 } 1804} 1805 1806/* Convert a KEY_RSA_CERT or KEY_DSA_CERT to their raw key equivalent */ 1807int 1808key_drop_cert(Key *k) 1809{ 1810 switch (k->type) { 1811 case KEY_RSA_CERT_V00: 1812 case KEY_RSA_CERT: 1813 cert_free(k->cert); 1814 k->type = KEY_RSA; 1815 return 0; 1816 case KEY_DSA_CERT_V00: 1817 case KEY_DSA_CERT: 1818 cert_free(k->cert); 1819 k->type = KEY_DSA; 1820 return 0; 1821 case KEY_ECDSA_CERT: 1822 cert_free(k->cert); 1823 k->type = KEY_ECDSA; 1824 return 0; 1825 default: 1826 error("%s: key has incorrect type %s", __func__, key_type(k)); 1827 return -1; 1828 } 1829} 1830 1831/* 1832 * Sign a KEY_RSA_CERT, KEY_DSA_CERT or KEY_ECDSA_CERT, (re-)generating 1833 * the signed certblob 1834 */ 1835int 1836key_certify(Key *k, Key *ca) 1837{ 1838 Buffer principals; 1839 u_char *ca_blob, *sig_blob, nonce[32]; 1840 u_int i, ca_len, sig_len; 1841 1842 if (k->cert == NULL) { 1843 error("%s: key lacks cert info", __func__); 1844 return -1; 1845 } 1846 1847 if (!key_is_cert(k)) { 1848 error("%s: certificate has unknown type %d", __func__, 1849 k->cert->type); 1850 return -1; 1851 } 1852 1853 if (ca->type != KEY_RSA && ca->type != KEY_DSA && 1854 ca->type != KEY_ECDSA) { 1855 error("%s: CA key has unsupported type %s", __func__, 1856 key_type(ca)); 1857 return -1; 1858 } 1859 1860 key_to_blob(ca, &ca_blob, &ca_len); 1861 1862 buffer_clear(&k->cert->certblob); 1863 buffer_put_cstring(&k->cert->certblob, key_ssh_name(k)); 1864 1865 /* -v01 certs put nonce first */ 1866 arc4random_buf(&nonce, sizeof(nonce)); 1867 if (!key_cert_is_legacy(k)) 1868 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce)); 1869 1870 switch (k->type) { 1871 case KEY_DSA_CERT_V00: 1872 case KEY_DSA_CERT: 1873 buffer_put_bignum2(&k->cert->certblob, k->dsa->p); 1874 buffer_put_bignum2(&k->cert->certblob, k->dsa->q); 1875 buffer_put_bignum2(&k->cert->certblob, k->dsa->g); 1876 buffer_put_bignum2(&k->cert->certblob, k->dsa->pub_key); 1877 break; 1878#ifdef OPENSSL_HAS_ECC 1879 case KEY_ECDSA_CERT: 1880 buffer_put_cstring(&k->cert->certblob, 1881 key_curve_nid_to_name(k->ecdsa_nid)); 1882 buffer_put_ecpoint(&k->cert->certblob, 1883 EC_KEY_get0_group(k->ecdsa), 1884 EC_KEY_get0_public_key(k->ecdsa)); 1885 break; 1886#endif 1887 case KEY_RSA_CERT_V00: 1888 case KEY_RSA_CERT: 1889 buffer_put_bignum2(&k->cert->certblob, k->rsa->e); 1890 buffer_put_bignum2(&k->cert->certblob, k->rsa->n); 1891 break; 1892 default: 1893 error("%s: key has incorrect type %s", __func__, key_type(k)); 1894 buffer_clear(&k->cert->certblob); 1895 free(ca_blob); 1896 return -1; 1897 } 1898 1899 /* -v01 certs have a serial number next */ 1900 if (!key_cert_is_legacy(k)) 1901 buffer_put_int64(&k->cert->certblob, k->cert->serial); 1902 1903 buffer_put_int(&k->cert->certblob, k->cert->type); 1904 buffer_put_cstring(&k->cert->certblob, k->cert->key_id); 1905 1906 buffer_init(&principals); 1907 for (i = 0; i < k->cert->nprincipals; i++) 1908 buffer_put_cstring(&principals, k->cert->principals[i]); 1909 buffer_put_string(&k->cert->certblob, buffer_ptr(&principals), 1910 buffer_len(&principals)); 1911 buffer_free(&principals); 1912 1913 buffer_put_int64(&k->cert->certblob, k->cert->valid_after); 1914 buffer_put_int64(&k->cert->certblob, k->cert->valid_before); 1915 buffer_put_string(&k->cert->certblob, 1916 buffer_ptr(&k->cert->critical), buffer_len(&k->cert->critical)); 1917 1918 /* -v01 certs have non-critical options here */ 1919 if (!key_cert_is_legacy(k)) { 1920 buffer_put_string(&k->cert->certblob, 1921 buffer_ptr(&k->cert->extensions), 1922 buffer_len(&k->cert->extensions)); 1923 } 1924 1925 /* -v00 certs put the nonce at the end */ 1926 if (key_cert_is_legacy(k)) 1927 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce)); 1928 1929 buffer_put_string(&k->cert->certblob, NULL, 0); /* reserved */ 1930 buffer_put_string(&k->cert->certblob, ca_blob, ca_len); 1931 free(ca_blob); 1932 1933 /* Sign the whole mess */ 1934 if (key_sign(ca, &sig_blob, &sig_len, buffer_ptr(&k->cert->certblob), 1935 buffer_len(&k->cert->certblob)) != 0) { 1936 error("%s: signature operation failed", __func__); 1937 buffer_clear(&k->cert->certblob); 1938 return -1; 1939 } 1940 /* Append signature and we are done */ 1941 buffer_put_string(&k->cert->certblob, sig_blob, sig_len); 1942 free(sig_blob); 1943 1944 return 0; 1945} 1946 1947int 1948key_cert_check_authority(const Key *k, int want_host, int require_principal, 1949 const char *name, const char **reason) 1950{ 1951 u_int i, principal_matches; 1952 time_t now = time(NULL); 1953 1954 if (want_host) { 1955 if (k->cert->type != SSH2_CERT_TYPE_HOST) { 1956 *reason = "Certificate invalid: not a host certificate"; 1957 return -1; 1958 } 1959 } else { 1960 if (k->cert->type != SSH2_CERT_TYPE_USER) { 1961 *reason = "Certificate invalid: not a user certificate"; 1962 return -1; 1963 } 1964 } 1965 if (now < 0) { 1966 error("%s: system clock lies before epoch", __func__); 1967 *reason = "Certificate invalid: not yet valid"; 1968 return -1; 1969 } 1970 if ((u_int64_t)now < k->cert->valid_after) { 1971 *reason = "Certificate invalid: not yet valid"; 1972 return -1; 1973 } 1974 if ((u_int64_t)now >= k->cert->valid_before) { 1975 *reason = "Certificate invalid: expired"; 1976 return -1; 1977 } 1978 if (k->cert->nprincipals == 0) { 1979 if (require_principal) { 1980 *reason = "Certificate lacks principal list"; 1981 return -1; 1982 } 1983 } else if (name != NULL) { 1984 principal_matches = 0; 1985 for (i = 0; i < k->cert->nprincipals; i++) { 1986 if (strcmp(name, k->cert->principals[i]) == 0) { 1987 principal_matches = 1; 1988 break; 1989 } 1990 } 1991 if (!principal_matches) { 1992 *reason = "Certificate invalid: name is not a listed " 1993 "principal"; 1994 return -1; 1995 } 1996 } 1997 return 0; 1998} 1999 2000int 2001key_cert_is_legacy(const Key *k) 2002{ 2003 switch (k->type) { 2004 case KEY_DSA_CERT_V00: 2005 case KEY_RSA_CERT_V00: 2006 return 1; 2007 default: 2008 return 0; 2009 } 2010} 2011 2012/* XXX: these are really begging for a table-driven approach */ 2013int 2014key_curve_name_to_nid(const char *name) 2015{ 2016#ifdef OPENSSL_HAS_ECC 2017 if (strcmp(name, "nistp256") == 0) 2018 return NID_X9_62_prime256v1; 2019 else if (strcmp(name, "nistp384") == 0) 2020 return NID_secp384r1; 2021 else if (strcmp(name, "nistp521") == 0) 2022 return NID_secp521r1; 2023#endif 2024 2025 debug("%s: unsupported EC curve name \"%.100s\"", __func__, name); 2026 return -1; 2027} 2028 2029u_int 2030key_curve_nid_to_bits(int nid) 2031{ 2032 switch (nid) { 2033#ifdef OPENSSL_HAS_ECC 2034 case NID_X9_62_prime256v1: 2035 return 256; 2036 case NID_secp384r1: 2037 return 384; 2038 case NID_secp521r1: 2039 return 521; 2040#endif 2041 default: 2042 error("%s: unsupported EC curve nid %d", __func__, nid); 2043 return 0; 2044 } 2045} 2046 2047const char * 2048key_curve_nid_to_name(int nid) 2049{ 2050#ifdef OPENSSL_HAS_ECC 2051 if (nid == NID_X9_62_prime256v1) 2052 return "nistp256"; 2053 else if (nid == NID_secp384r1) 2054 return "nistp384"; 2055 else if (nid == NID_secp521r1) 2056 return "nistp521"; 2057#endif 2058 error("%s: unsupported EC curve nid %d", __func__, nid); 2059 return NULL; 2060} 2061 2062#ifdef OPENSSL_HAS_ECC 2063const EVP_MD * 2064key_ec_nid_to_evpmd(int nid) 2065{ 2066 int kbits = key_curve_nid_to_bits(nid); 2067 2068 if (kbits == 0) 2069 fatal("%s: invalid nid %d", __func__, nid); 2070 /* RFC5656 section 6.2.1 */ 2071 if (kbits <= 256) 2072 return EVP_sha256(); 2073 else if (kbits <= 384) 2074 return EVP_sha384(); 2075 else 2076 return EVP_sha512(); 2077} 2078 2079int 2080key_ec_validate_public(const EC_GROUP *group, const EC_POINT *public) 2081{ 2082 BN_CTX *bnctx; 2083 EC_POINT *nq = NULL; 2084 BIGNUM *order, *x, *y, *tmp; 2085 int ret = -1; 2086 2087 if ((bnctx = BN_CTX_new()) == NULL) 2088 fatal("%s: BN_CTX_new failed", __func__); 2089 BN_CTX_start(bnctx); 2090 2091 /* 2092 * We shouldn't ever hit this case because bignum_get_ecpoint() 2093 * refuses to load GF2m points. 2094 */ 2095 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) != 2096 NID_X9_62_prime_field) { 2097 error("%s: group is not a prime field", __func__); 2098 goto out; 2099 } 2100 2101 /* Q != infinity */ 2102 if (EC_POINT_is_at_infinity(group, public)) { 2103 error("%s: received degenerate public key (infinity)", 2104 __func__); 2105 goto out; 2106 } 2107 2108 if ((x = BN_CTX_get(bnctx)) == NULL || 2109 (y = BN_CTX_get(bnctx)) == NULL || 2110 (order = BN_CTX_get(bnctx)) == NULL || 2111 (tmp = BN_CTX_get(bnctx)) == NULL) 2112 fatal("%s: BN_CTX_get failed", __func__); 2113 2114 /* log2(x) > log2(order)/2, log2(y) > log2(order)/2 */ 2115 if (EC_GROUP_get_order(group, order, bnctx) != 1) 2116 fatal("%s: EC_GROUP_get_order failed", __func__); 2117 if (EC_POINT_get_affine_coordinates_GFp(group, public, 2118 x, y, bnctx) != 1) 2119 fatal("%s: EC_POINT_get_affine_coordinates_GFp", __func__); 2120 if (BN_num_bits(x) <= BN_num_bits(order) / 2) { 2121 error("%s: public key x coordinate too small: " 2122 "bits(x) = %d, bits(order)/2 = %d", __func__, 2123 BN_num_bits(x), BN_num_bits(order) / 2); 2124 goto out; 2125 } 2126 if (BN_num_bits(y) <= BN_num_bits(order) / 2) { 2127 error("%s: public key y coordinate too small: " 2128 "bits(y) = %d, bits(order)/2 = %d", __func__, 2129 BN_num_bits(x), BN_num_bits(order) / 2); 2130 goto out; 2131 } 2132 2133 /* nQ == infinity (n == order of subgroup) */ 2134 if ((nq = EC_POINT_new(group)) == NULL) 2135 fatal("%s: BN_CTX_tmp failed", __func__); 2136 if (EC_POINT_mul(group, nq, NULL, public, order, bnctx) != 1) 2137 fatal("%s: EC_GROUP_mul failed", __func__); 2138 if (EC_POINT_is_at_infinity(group, nq) != 1) { 2139 error("%s: received degenerate public key (nQ != infinity)", 2140 __func__); 2141 goto out; 2142 } 2143 2144 /* x < order - 1, y < order - 1 */ 2145 if (!BN_sub(tmp, order, BN_value_one())) 2146 fatal("%s: BN_sub failed", __func__); 2147 if (BN_cmp(x, tmp) >= 0) { 2148 error("%s: public key x coordinate >= group order - 1", 2149 __func__); 2150 goto out; 2151 } 2152 if (BN_cmp(y, tmp) >= 0) { 2153 error("%s: public key y coordinate >= group order - 1", 2154 __func__); 2155 goto out; 2156 } 2157 ret = 0; 2158 out: 2159 BN_CTX_free(bnctx); 2160 EC_POINT_free(nq); 2161 return ret; 2162} 2163 2164int 2165key_ec_validate_private(const EC_KEY *key) 2166{ 2167 BN_CTX *bnctx; 2168 BIGNUM *order, *tmp; 2169 int ret = -1; 2170 2171 if ((bnctx = BN_CTX_new()) == NULL) 2172 fatal("%s: BN_CTX_new failed", __func__); 2173 BN_CTX_start(bnctx); 2174 2175 if ((order = BN_CTX_get(bnctx)) == NULL || 2176 (tmp = BN_CTX_get(bnctx)) == NULL) 2177 fatal("%s: BN_CTX_get failed", __func__); 2178 2179 /* log2(private) > log2(order)/2 */ 2180 if (EC_GROUP_get_order(EC_KEY_get0_group(key), order, bnctx) != 1) 2181 fatal("%s: EC_GROUP_get_order failed", __func__); 2182 if (BN_num_bits(EC_KEY_get0_private_key(key)) <= 2183 BN_num_bits(order) / 2) { 2184 error("%s: private key too small: " 2185 "bits(y) = %d, bits(order)/2 = %d", __func__, 2186 BN_num_bits(EC_KEY_get0_private_key(key)), 2187 BN_num_bits(order) / 2); 2188 goto out; 2189 } 2190 2191 /* private < order - 1 */ 2192 if (!BN_sub(tmp, order, BN_value_one())) 2193 fatal("%s: BN_sub failed", __func__); 2194 if (BN_cmp(EC_KEY_get0_private_key(key), tmp) >= 0) { 2195 error("%s: private key >= group order - 1", __func__); 2196 goto out; 2197 } 2198 ret = 0; 2199 out: 2200 BN_CTX_free(bnctx); 2201 return ret; 2202} 2203 2204#if defined(DEBUG_KEXECDH) || defined(DEBUG_PK) 2205void 2206key_dump_ec_point(const EC_GROUP *group, const EC_POINT *point) 2207{ 2208 BIGNUM *x, *y; 2209 BN_CTX *bnctx; 2210 2211 if (point == NULL) { 2212 fputs("point=(NULL)\n", stderr); 2213 return; 2214 } 2215 if ((bnctx = BN_CTX_new()) == NULL) 2216 fatal("%s: BN_CTX_new failed", __func__); 2217 BN_CTX_start(bnctx); 2218 if ((x = BN_CTX_get(bnctx)) == NULL || (y = BN_CTX_get(bnctx)) == NULL) 2219 fatal("%s: BN_CTX_get failed", __func__); 2220 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) != 2221 NID_X9_62_prime_field) 2222 fatal("%s: group is not a prime field", __func__); 2223 if (EC_POINT_get_affine_coordinates_GFp(group, point, x, y, bnctx) != 1) 2224 fatal("%s: EC_POINT_get_affine_coordinates_GFp", __func__); 2225 fputs("x=", stderr); 2226 BN_print_fp(stderr, x); 2227 fputs("\ny=", stderr); 2228 BN_print_fp(stderr, y); 2229 fputs("\n", stderr); 2230 BN_CTX_free(bnctx); 2231} 2232 2233void 2234key_dump_ec_key(const EC_KEY *key) 2235{ 2236 const BIGNUM *exponent; 2237 2238 key_dump_ec_point(EC_KEY_get0_group(key), EC_KEY_get0_public_key(key)); 2239 fputs("exponent=", stderr); 2240 if ((exponent = EC_KEY_get0_private_key(key)) == NULL) 2241 fputs("(NULL)", stderr); 2242 else 2243 BN_print_fp(stderr, EC_KEY_get0_private_key(key)); 2244 fputs("\n", stderr); 2245} 2246#endif /* defined(DEBUG_KEXECDH) || defined(DEBUG_PK) */ 2247#endif /* OPENSSL_HAS_ECC */ 2248