1 /* $OpenBSD: key.c,v 1.90 2010/07/13 23:13:16 djm Exp $ */
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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".
13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
14 * Copyright (c) 2008 Alexander von Gernler. All rights reserved.
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
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.
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.
39 #include <sys/param.h>
40 #include <sys/types.h>
42 #include <openssl/evp.h>
43 #include <openbsd-compat/openssl-compat.h>
58 static struct KeyCert *
63 cert = xcalloc(1, sizeof(*cert));
64 buffer_init(&cert->certblob);
65 buffer_init(&cert->critical);
66 buffer_init(&cert->extensions);
68 cert->principals = NULL;
69 cert->signature_key = NULL;
79 k = xcalloc(1, sizeof(*k));
87 case KEY_RSA_CERT_V00:
89 if ((rsa = RSA_new()) == NULL)
90 fatal("key_new: RSA_new failed");
91 if ((rsa->n = BN_new()) == NULL)
92 fatal("key_new: BN_new failed");
93 if ((rsa->e = BN_new()) == NULL)
94 fatal("key_new: BN_new failed");
98 case KEY_DSA_CERT_V00:
100 if ((dsa = DSA_new()) == NULL)
101 fatal("key_new: DSA_new failed");
102 if ((dsa->p = BN_new()) == NULL)
103 fatal("key_new: BN_new failed");
104 if ((dsa->q = BN_new()) == NULL)
105 fatal("key_new: BN_new failed");
106 if ((dsa->g = BN_new()) == NULL)
107 fatal("key_new: BN_new failed");
108 if ((dsa->pub_key = BN_new()) == NULL)
109 fatal("key_new: BN_new failed");
115 fatal("key_new: bad key type %d", k->type);
120 k->cert = cert_new();
126 key_add_private(Key *k)
131 case KEY_RSA_CERT_V00:
133 if ((k->rsa->d = BN_new()) == NULL)
134 fatal("key_new_private: BN_new failed");
135 if ((k->rsa->iqmp = BN_new()) == NULL)
136 fatal("key_new_private: BN_new failed");
137 if ((k->rsa->q = BN_new()) == NULL)
138 fatal("key_new_private: BN_new failed");
139 if ((k->rsa->p = BN_new()) == NULL)
140 fatal("key_new_private: BN_new failed");
141 if ((k->rsa->dmq1 = BN_new()) == NULL)
142 fatal("key_new_private: BN_new failed");
143 if ((k->rsa->dmp1 = BN_new()) == NULL)
144 fatal("key_new_private: BN_new failed");
147 case KEY_DSA_CERT_V00:
149 if ((k->dsa->priv_key = BN_new()) == NULL)
150 fatal("key_new_private: BN_new failed");
160 key_new_private(int type)
162 Key *k = key_new(type);
169 cert_free(struct KeyCert *cert)
173 buffer_free(&cert->certblob);
174 buffer_free(&cert->critical);
175 buffer_free(&cert->extensions);
176 if (cert->key_id != NULL)
178 for (i = 0; i < cert->nprincipals; i++)
179 xfree(cert->principals[i]);
180 if (cert->principals != NULL)
181 xfree(cert->principals);
182 if (cert->signature_key != NULL)
183 key_free(cert->signature_key);
190 fatal("key_free: key is NULL");
194 case KEY_RSA_CERT_V00:
201 case KEY_DSA_CERT_V00:
210 fatal("key_free: bad key type %d", k->type);
213 if (key_is_cert(k)) {
223 cert_compare(struct KeyCert *a, struct KeyCert *b)
225 if (a == NULL && b == NULL)
227 if (a == NULL || b == NULL)
229 if (buffer_len(&a->certblob) != buffer_len(&b->certblob))
231 if (timingsafe_bcmp(buffer_ptr(&a->certblob), buffer_ptr(&b->certblob),
232 buffer_len(&a->certblob)) != 0)
238 * Compare public portions of key only, allowing comparisons between
239 * certificates and plain keys too.
242 key_equal_public(const Key *a, const Key *b)
244 if (a == NULL || b == NULL ||
245 key_type_plain(a->type) != key_type_plain(b->type))
250 case KEY_RSA_CERT_V00:
253 return a->rsa != NULL && b->rsa != NULL &&
254 BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
255 BN_cmp(a->rsa->n, b->rsa->n) == 0;
256 case KEY_DSA_CERT_V00:
259 return a->dsa != NULL && b->dsa != NULL &&
260 BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
261 BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
262 BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
263 BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
265 fatal("key_equal: bad key type %d", a->type);
271 key_equal(const Key *a, const Key *b)
273 if (a == NULL || b == NULL || a->type != b->type)
275 if (key_is_cert(a)) {
276 if (!cert_compare(a->cert, b->cert))
279 return key_equal_public(a, b);
283 key_fingerprint_raw(Key *k, enum fp_type dgst_type, u_int *dgst_raw_length)
285 const EVP_MD *md = NULL;
288 u_char *retval = NULL;
290 int nlen, elen, otype;
292 *dgst_raw_length = 0;
302 fatal("key_fingerprint_raw: bad digest type %d",
307 nlen = BN_num_bytes(k->rsa->n);
308 elen = BN_num_bytes(k->rsa->e);
311 BN_bn2bin(k->rsa->n, blob);
312 BN_bn2bin(k->rsa->e, blob + nlen);
316 key_to_blob(k, &blob, &len);
318 case KEY_DSA_CERT_V00:
319 case KEY_RSA_CERT_V00:
322 /* We want a fingerprint of the _key_ not of the cert */
324 k->type = key_type_plain(k->type);
325 key_to_blob(k, &blob, &len);
331 fatal("key_fingerprint_raw: bad key type %d", k->type);
335 retval = xmalloc(EVP_MAX_MD_SIZE);
336 EVP_DigestInit(&ctx, md);
337 EVP_DigestUpdate(&ctx, blob, len);
338 EVP_DigestFinal(&ctx, retval, dgst_raw_length);
339 memset(blob, 0, len);
342 fatal("key_fingerprint_raw: blob is null");
348 key_fingerprint_hex(u_char *dgst_raw, u_int dgst_raw_len)
353 retval = xcalloc(1, dgst_raw_len * 3 + 1);
354 for (i = 0; i < dgst_raw_len; i++) {
356 snprintf(hex, sizeof(hex), "%02x:", dgst_raw[i]);
357 strlcat(retval, hex, dgst_raw_len * 3 + 1);
360 /* Remove the trailing ':' character */
361 retval[(dgst_raw_len * 3) - 1] = '\0';
366 key_fingerprint_bubblebabble(u_char *dgst_raw, u_int dgst_raw_len)
368 char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
369 char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
370 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
371 u_int i, j = 0, rounds, seed = 1;
374 rounds = (dgst_raw_len / 2) + 1;
375 retval = xcalloc((rounds * 6), sizeof(char));
377 for (i = 0; i < rounds; i++) {
378 u_int idx0, idx1, idx2, idx3, idx4;
379 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) {
380 idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) +
382 idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15;
383 idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) +
385 retval[j++] = vowels[idx0];
386 retval[j++] = consonants[idx1];
387 retval[j++] = vowels[idx2];
388 if ((i + 1) < rounds) {
389 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15;
390 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15;
391 retval[j++] = consonants[idx3];
393 retval[j++] = consonants[idx4];
395 ((((u_int)(dgst_raw[2 * i])) * 7) +
396 ((u_int)(dgst_raw[(2 * i) + 1])))) % 36;
402 retval[j++] = vowels[idx0];
403 retval[j++] = consonants[idx1];
404 retval[j++] = vowels[idx2];
413 * Draw an ASCII-Art representing the fingerprint so human brain can
414 * profit from its built-in pattern recognition ability.
415 * This technique is called "random art" and can be found in some
416 * scientific publications like this original paper:
418 * "Hash Visualization: a New Technique to improve Real-World Security",
419 * Perrig A. and Song D., 1999, International Workshop on Cryptographic
420 * Techniques and E-Commerce (CrypTEC '99)
421 * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
423 * The subject came up in a talk by Dan Kaminsky, too.
425 * If you see the picture is different, the key is different.
426 * If the picture looks the same, you still know nothing.
428 * The algorithm used here is a worm crawling over a discrete plane,
429 * leaving a trace (augmenting the field) everywhere it goes.
430 * Movement is taken from dgst_raw 2bit-wise. Bumping into walls
431 * makes the respective movement vector be ignored for this turn.
432 * Graphs are not unambiguous, because circles in graphs can be
433 * walked in either direction.
437 * Field sizes for the random art. Have to be odd, so the starting point
438 * can be in the exact middle of the picture, and FLDBASE should be >=8 .
439 * Else pictures would be too dense, and drawing the frame would
440 * fail, too, because the key type would not fit in anymore.
443 #define FLDSIZE_Y (FLDBASE + 1)
444 #define FLDSIZE_X (FLDBASE * 2 + 1)
446 key_fingerprint_randomart(u_char *dgst_raw, u_int dgst_raw_len, const Key *k)
449 * Chars to be used after each other every time the worm
450 * intersects with itself. Matter of taste.
452 char *augmentation_string = " .o+=*BOX@%&#/^SE";
454 u_char field[FLDSIZE_X][FLDSIZE_Y];
457 size_t len = strlen(augmentation_string) - 1;
459 retval = xcalloc(1, (FLDSIZE_X + 3) * (FLDSIZE_Y + 2));
461 /* initialize field */
462 memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char));
466 /* process raw key */
467 for (i = 0; i < dgst_raw_len; i++) {
469 /* each byte conveys four 2-bit move commands */
471 for (b = 0; b < 4; b++) {
472 /* evaluate 2 bit, rest is shifted later */
473 x += (input & 0x1) ? 1 : -1;
474 y += (input & 0x2) ? 1 : -1;
476 /* assure we are still in bounds */
479 x = MIN(x, FLDSIZE_X - 1);
480 y = MIN(y, FLDSIZE_Y - 1);
482 /* augment the field */
483 if (field[x][y] < len - 2)
489 /* mark starting point and end point*/
490 field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1;
494 snprintf(retval, FLDSIZE_X, "+--[%4s %4u]", key_type(k), key_size(k));
495 p = strchr(retval, '\0');
497 /* output upper border */
498 for (i = p - retval - 1; i < FLDSIZE_X; i++)
504 for (y = 0; y < FLDSIZE_Y; y++) {
506 for (x = 0; x < FLDSIZE_X; x++)
507 *p++ = augmentation_string[MIN(field[x][y], len)];
512 /* output lower border */
514 for (i = 0; i < FLDSIZE_X; i++)
522 key_fingerprint(Key *k, enum fp_type dgst_type, enum fp_rep dgst_rep)
528 dgst_raw = key_fingerprint_raw(k, dgst_type, &dgst_raw_len);
530 fatal("key_fingerprint: null from key_fingerprint_raw()");
533 retval = key_fingerprint_hex(dgst_raw, dgst_raw_len);
535 case SSH_FP_BUBBLEBABBLE:
536 retval = key_fingerprint_bubblebabble(dgst_raw, dgst_raw_len);
538 case SSH_FP_RANDOMART:
539 retval = key_fingerprint_randomart(dgst_raw, dgst_raw_len, k);
542 fatal("key_fingerprint: bad digest representation %d",
546 memset(dgst_raw, 0, dgst_raw_len);
552 * Reads a multiple-precision integer in decimal from the buffer, and advances
553 * the pointer. The integer must already be initialized. This function is
554 * permitted to modify the buffer. This leaves *cpp to point just beyond the
555 * last processed (and maybe modified) character. Note that this may modify
556 * the buffer containing the number.
559 read_bignum(char **cpp, BIGNUM * value)
564 /* Skip any leading whitespace. */
565 for (; *cp == ' ' || *cp == '\t'; cp++)
568 /* Check that it begins with a decimal digit. */
569 if (*cp < '0' || *cp > '9')
572 /* Save starting position. */
575 /* Move forward until all decimal digits skipped. */
576 for (; *cp >= '0' && *cp <= '9'; cp++)
579 /* Save the old terminating character, and replace it by \0. */
583 /* Parse the number. */
584 if (BN_dec2bn(&value, *cpp) == 0)
587 /* Restore old terminating character. */
590 /* Move beyond the number and return success. */
596 write_bignum(FILE *f, BIGNUM *num)
598 char *buf = BN_bn2dec(num);
600 error("write_bignum: BN_bn2dec() failed");
603 fprintf(f, " %s", buf);
608 /* returns 1 ok, -1 error */
610 key_read(Key *ret, char **cpp)
623 /* Get number of bits. */
624 if (*cp < '0' || *cp > '9')
625 return -1; /* Bad bit count... */
626 for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
627 bits = 10 * bits + *cp - '0';
631 /* Get public exponent, public modulus. */
632 if (!read_bignum(cpp, ret->rsa->e))
634 if (!read_bignum(cpp, ret->rsa->n))
636 /* validate the claimed number of bits */
637 if ((u_int)BN_num_bits(ret->rsa->n) != bits) {
638 verbose("key_read: claimed key size %d does not match "
639 "actual %d", bits, BN_num_bits(ret->rsa->n));
647 case KEY_DSA_CERT_V00:
648 case KEY_RSA_CERT_V00:
651 space = strchr(cp, ' ');
653 debug3("key_read: missing whitespace");
657 type = key_type_from_name(cp);
659 if (type == KEY_UNSPEC) {
660 debug3("key_read: missing keytype");
665 debug3("key_read: short string");
668 if (ret->type == KEY_UNSPEC) {
670 } else if (ret->type != type) {
671 /* is a key, but different type */
672 debug3("key_read: type mismatch");
677 n = uudecode(cp, blob, len);
679 error("key_read: uudecode %s failed", cp);
683 k = key_from_blob(blob, (u_int)n);
686 error("key_read: key_from_blob %s failed", cp);
689 if (k->type != type) {
690 error("key_read: type mismatch: encoding error");
695 if (key_is_cert(ret)) {
696 if (!key_is_cert(k)) {
697 error("key_read: loaded key is not a cert");
701 if (ret->cert != NULL)
702 cert_free(ret->cert);
706 if (key_type_plain(ret->type) == KEY_RSA) {
707 if (ret->rsa != NULL)
712 RSA_print_fp(stderr, ret->rsa, 8);
715 if (key_type_plain(ret->type) == KEY_DSA) {
716 if (ret->dsa != NULL)
721 DSA_print_fp(stderr, ret->dsa, 8);
729 /* advance cp: skip whitespace and data */
730 while (*cp == ' ' || *cp == '\t')
732 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
737 fatal("key_read: bad key type: %d", ret->type);
744 key_write(const Key *key, FILE *f)
751 if (key_is_cert(key)) {
752 if (key->cert == NULL) {
753 error("%s: no cert data", __func__);
756 if (buffer_len(&key->cert->certblob) == 0) {
757 error("%s: no signed certificate blob", __func__);
764 if (key->rsa == NULL)
766 /* size of modulus 'n' */
767 bits = BN_num_bits(key->rsa->n);
768 fprintf(f, "%u", bits);
769 if (write_bignum(f, key->rsa->e) &&
770 write_bignum(f, key->rsa->n))
772 error("key_write: failed for RSA key");
775 case KEY_DSA_CERT_V00:
777 if (key->dsa == NULL)
781 case KEY_RSA_CERT_V00:
783 if (key->rsa == NULL)
790 key_to_blob(key, &blob, &len);
792 n = uuencode(blob, len, uu, 2*len);
794 fprintf(f, "%s %s", key_ssh_name(key), uu);
804 key_type(const Key *k)
813 case KEY_RSA_CERT_V00:
814 return "RSA-CERT-V00";
815 case KEY_DSA_CERT_V00:
816 return "DSA-CERT-V00";
826 key_cert_type(const Key *k)
828 switch (k->cert->type) {
829 case SSH2_CERT_TYPE_USER:
831 case SSH2_CERT_TYPE_HOST:
839 key_ssh_name(const Key *k)
846 case KEY_RSA_CERT_V00:
847 return "ssh-rsa-cert-v00@openssh.com";
848 case KEY_DSA_CERT_V00:
849 return "ssh-dss-cert-v00@openssh.com";
851 return "ssh-rsa-cert-v01@openssh.com";
853 return "ssh-dss-cert-v01@openssh.com";
855 return "ssh-unknown";
859 key_size(const Key *k)
864 case KEY_RSA_CERT_V00:
866 return BN_num_bits(k->rsa->n);
868 case KEY_DSA_CERT_V00:
870 return BN_num_bits(k->dsa->p);
876 rsa_generate_private_key(u_int bits)
880 private = RSA_generate_key(bits, RSA_F4, NULL, NULL);
882 fatal("rsa_generate_private_key: key generation failed.");
887 dsa_generate_private_key(u_int bits)
889 DSA *private = DSA_generate_parameters(bits, NULL, 0, NULL, NULL, NULL, NULL);
892 fatal("dsa_generate_private_key: DSA_generate_parameters failed");
893 if (!DSA_generate_key(private))
894 fatal("dsa_generate_private_key: DSA_generate_key failed.");
896 fatal("dsa_generate_private_key: NULL.");
901 key_generate(int type, u_int bits)
903 Key *k = key_new(KEY_UNSPEC);
906 k->dsa = dsa_generate_private_key(bits);
910 k->rsa = rsa_generate_private_key(bits);
912 case KEY_RSA_CERT_V00:
913 case KEY_DSA_CERT_V00:
916 fatal("key_generate: cert keys cannot be generated directly");
918 fatal("key_generate: unknown type %d", type);
925 key_cert_copy(const Key *from_key, struct Key *to_key)
928 const struct KeyCert *from;
931 if (to_key->cert != NULL) {
932 cert_free(to_key->cert);
936 if ((from = from_key->cert) == NULL)
939 to = to_key->cert = cert_new();
941 buffer_append(&to->certblob, buffer_ptr(&from->certblob),
942 buffer_len(&from->certblob));
944 buffer_append(&to->critical,
945 buffer_ptr(&from->critical), buffer_len(&from->critical));
946 buffer_append(&to->extensions,
947 buffer_ptr(&from->extensions), buffer_len(&from->extensions));
949 to->serial = from->serial;
950 to->type = from->type;
951 to->key_id = from->key_id == NULL ? NULL : xstrdup(from->key_id);
952 to->valid_after = from->valid_after;
953 to->valid_before = from->valid_before;
954 to->signature_key = from->signature_key == NULL ?
955 NULL : key_from_private(from->signature_key);
957 to->nprincipals = from->nprincipals;
958 if (to->nprincipals > CERT_MAX_PRINCIPALS)
959 fatal("%s: nprincipals (%u) > CERT_MAX_PRINCIPALS (%u)",
960 __func__, to->nprincipals, CERT_MAX_PRINCIPALS);
961 if (to->nprincipals > 0) {
962 to->principals = xcalloc(from->nprincipals,
963 sizeof(*to->principals));
964 for (i = 0; i < to->nprincipals; i++)
965 to->principals[i] = xstrdup(from->principals[i]);
970 key_from_private(const Key *k)
975 case KEY_DSA_CERT_V00:
977 n = key_new(k->type);
978 if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) ||
979 (BN_copy(n->dsa->q, k->dsa->q) == NULL) ||
980 (BN_copy(n->dsa->g, k->dsa->g) == NULL) ||
981 (BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL))
982 fatal("key_from_private: BN_copy failed");
986 case KEY_RSA_CERT_V00:
988 n = key_new(k->type);
989 if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) ||
990 (BN_copy(n->rsa->e, k->rsa->e) == NULL))
991 fatal("key_from_private: BN_copy failed");
994 fatal("key_from_private: unknown type %d", k->type);
1003 key_type_from_name(char *name)
1005 if (strcmp(name, "rsa1") == 0) {
1007 } else if (strcmp(name, "rsa") == 0) {
1009 } else if (strcmp(name, "dsa") == 0) {
1011 } else if (strcmp(name, "ssh-rsa") == 0) {
1013 } else if (strcmp(name, "ssh-dss") == 0) {
1015 } else if (strcmp(name, "ssh-rsa-cert-v00@openssh.com") == 0) {
1016 return KEY_RSA_CERT_V00;
1017 } else if (strcmp(name, "ssh-dss-cert-v00@openssh.com") == 0) {
1018 return KEY_DSA_CERT_V00;
1019 } else if (strcmp(name, "ssh-rsa-cert-v01@openssh.com") == 0) {
1020 return KEY_RSA_CERT;
1021 } else if (strcmp(name, "ssh-dss-cert-v01@openssh.com") == 0) {
1022 return KEY_DSA_CERT;
1024 debug2("key_type_from_name: unknown key type '%s'", name);
1029 key_names_valid2(const char *names)
1033 if (names == NULL || strcmp(names, "") == 0)
1035 s = cp = xstrdup(names);
1036 for ((p = strsep(&cp, ",")); p && *p != '\0';
1037 (p = strsep(&cp, ","))) {
1038 switch (key_type_from_name(p)) {
1045 debug3("key names ok: [%s]", names);
1051 cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
1053 u_char *principals, *critical, *exts, *sig_key, *sig;
1054 u_int signed_len, plen, clen, sklen, slen, kidlen, elen;
1058 int v00 = key->type == KEY_DSA_CERT_V00 ||
1059 key->type == KEY_RSA_CERT_V00;
1063 /* Copy the entire key blob for verification and later serialisation */
1064 buffer_append(&key->cert->certblob, blob, blen);
1066 elen = 0; /* Not touched for v00 certs */
1067 principals = exts = critical = sig_key = sig = NULL;
1068 if ((!v00 && buffer_get_int64_ret(&key->cert->serial, b) != 0) ||
1069 buffer_get_int_ret(&key->cert->type, b) != 0 ||
1070 (key->cert->key_id = buffer_get_string_ret(b, &kidlen)) == NULL ||
1071 (principals = buffer_get_string_ret(b, &plen)) == NULL ||
1072 buffer_get_int64_ret(&key->cert->valid_after, b) != 0 ||
1073 buffer_get_int64_ret(&key->cert->valid_before, b) != 0 ||
1074 (critical = buffer_get_string_ret(b, &clen)) == NULL ||
1075 (!v00 && (exts = buffer_get_string_ret(b, &elen)) == NULL) ||
1076 (v00 && buffer_get_string_ptr_ret(b, NULL) == NULL) || /* nonce */
1077 buffer_get_string_ptr_ret(b, NULL) == NULL || /* reserved */
1078 (sig_key = buffer_get_string_ret(b, &sklen)) == NULL) {
1079 error("%s: parse error", __func__);
1083 if (kidlen != strlen(key->cert->key_id)) {
1084 error("%s: key ID contains \\0 character", __func__);
1088 /* Signature is left in the buffer so we can calculate this length */
1089 signed_len = buffer_len(&key->cert->certblob) - buffer_len(b);
1091 if ((sig = buffer_get_string_ret(b, &slen)) == NULL) {
1092 error("%s: parse error", __func__);
1096 if (key->cert->type != SSH2_CERT_TYPE_USER &&
1097 key->cert->type != SSH2_CERT_TYPE_HOST) {
1098 error("Unknown certificate type %u", key->cert->type);
1102 buffer_append(&tmp, principals, plen);
1103 while (buffer_len(&tmp) > 0) {
1104 if (key->cert->nprincipals >= CERT_MAX_PRINCIPALS) {
1105 error("%s: Too many principals", __func__);
1108 if ((principal = buffer_get_string_ret(&tmp, &plen)) == NULL) {
1109 error("%s: Principals data invalid", __func__);
1112 if (strlen(principal) != plen) {
1113 error("%s: Principal contains \\0 character",
1117 key->cert->principals = xrealloc(key->cert->principals,
1118 key->cert->nprincipals + 1, sizeof(*key->cert->principals));
1119 key->cert->principals[key->cert->nprincipals++] = principal;
1124 buffer_append(&key->cert->critical, critical, clen);
1125 buffer_append(&tmp, critical, clen);
1126 /* validate structure */
1127 while (buffer_len(&tmp) != 0) {
1128 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL ||
1129 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) {
1130 error("%s: critical option data invalid", __func__);
1136 buffer_append(&key->cert->extensions, exts, elen);
1137 buffer_append(&tmp, exts, elen);
1138 /* validate structure */
1139 while (buffer_len(&tmp) != 0) {
1140 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL ||
1141 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) {
1142 error("%s: extension data invalid", __func__);
1148 if ((key->cert->signature_key = key_from_blob(sig_key,
1150 error("%s: Signature key invalid", __func__);
1153 if (key->cert->signature_key->type != KEY_RSA &&
1154 key->cert->signature_key->type != KEY_DSA) {
1155 error("%s: Invalid signature key type %s (%d)", __func__,
1156 key_type(key->cert->signature_key),
1157 key->cert->signature_key->type);
1161 switch (key_verify(key->cert->signature_key, sig, slen,
1162 buffer_ptr(&key->cert->certblob), signed_len)) {
1165 break; /* Good signature */
1167 error("%s: Invalid signature on certificate", __func__);
1170 error("%s: Certificate signature verification failed",
1177 if (principals != NULL)
1179 if (critical != NULL)
1183 if (sig_key != NULL)
1191 key_from_blob(const u_char *blob, u_int blen)
1199 dump_base64(stderr, blob, blen);
1202 buffer_append(&b, blob, blen);
1203 if ((ktype = buffer_get_string_ret(&b, NULL)) == NULL) {
1204 error("key_from_blob: can't read key type");
1208 type = key_type_from_name(ktype);
1212 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */
1215 case KEY_RSA_CERT_V00:
1216 key = key_new(type);
1217 if (buffer_get_bignum2_ret(&b, key->rsa->e) == -1 ||
1218 buffer_get_bignum2_ret(&b, key->rsa->n) == -1) {
1219 error("key_from_blob: can't read rsa key");
1226 RSA_print_fp(stderr, key->rsa, 8);
1230 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */
1233 case KEY_DSA_CERT_V00:
1234 key = key_new(type);
1235 if (buffer_get_bignum2_ret(&b, key->dsa->p) == -1 ||
1236 buffer_get_bignum2_ret(&b, key->dsa->q) == -1 ||
1237 buffer_get_bignum2_ret(&b, key->dsa->g) == -1 ||
1238 buffer_get_bignum2_ret(&b, key->dsa->pub_key) == -1) {
1239 error("key_from_blob: can't read dsa key");
1243 DSA_print_fp(stderr, key->dsa, 8);
1247 key = key_new(type);
1250 error("key_from_blob: cannot handle type %s", ktype);
1253 if (key_is_cert(key) && cert_parse(&b, key, blob, blen) == -1) {
1254 error("key_from_blob: can't parse cert data");
1257 rlen = buffer_len(&b);
1258 if (key != NULL && rlen != 0)
1259 error("key_from_blob: remaining bytes in key blob %d", rlen);
1268 key_to_blob(const Key *key, u_char **blobp, u_int *lenp)
1274 error("key_to_blob: key == NULL");
1278 switch (key->type) {
1279 case KEY_DSA_CERT_V00:
1280 case KEY_RSA_CERT_V00:
1283 /* Use the existing blob */
1284 buffer_append(&b, buffer_ptr(&key->cert->certblob),
1285 buffer_len(&key->cert->certblob));
1288 buffer_put_cstring(&b, key_ssh_name(key));
1289 buffer_put_bignum2(&b, key->dsa->p);
1290 buffer_put_bignum2(&b, key->dsa->q);
1291 buffer_put_bignum2(&b, key->dsa->g);
1292 buffer_put_bignum2(&b, key->dsa->pub_key);
1295 buffer_put_cstring(&b, key_ssh_name(key));
1296 buffer_put_bignum2(&b, key->rsa->e);
1297 buffer_put_bignum2(&b, key->rsa->n);
1300 error("key_to_blob: unsupported key type %d", key->type);
1304 len = buffer_len(&b);
1307 if (blobp != NULL) {
1308 *blobp = xmalloc(len);
1309 memcpy(*blobp, buffer_ptr(&b), len);
1311 memset(buffer_ptr(&b), 0, len);
1319 u_char **sigp, u_int *lenp,
1320 const u_char *data, u_int datalen)
1322 switch (key->type) {
1323 case KEY_DSA_CERT_V00:
1326 return ssh_dss_sign(key, sigp, lenp, data, datalen);
1327 case KEY_RSA_CERT_V00:
1330 return ssh_rsa_sign(key, sigp, lenp, data, datalen);
1332 error("key_sign: invalid key type %d", key->type);
1338 * key_verify returns 1 for a correct signature, 0 for an incorrect signature
1344 const u_char *signature, u_int signaturelen,
1345 const u_char *data, u_int datalen)
1347 if (signaturelen == 0)
1350 switch (key->type) {
1351 case KEY_DSA_CERT_V00:
1354 return ssh_dss_verify(key, signature, signaturelen, data, datalen);
1355 case KEY_RSA_CERT_V00:
1358 return ssh_rsa_verify(key, signature, signaturelen, data, datalen);
1360 error("key_verify: invalid key type %d", key->type);
1365 /* Converts a private to a public key */
1367 key_demote(const Key *k)
1371 pk = xcalloc(1, sizeof(*pk));
1373 pk->flags = k->flags;
1378 case KEY_RSA_CERT_V00:
1380 key_cert_copy(k, pk);
1384 if ((pk->rsa = RSA_new()) == NULL)
1385 fatal("key_demote: RSA_new failed");
1386 if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL)
1387 fatal("key_demote: BN_dup failed");
1388 if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL)
1389 fatal("key_demote: BN_dup failed");
1391 case KEY_DSA_CERT_V00:
1393 key_cert_copy(k, pk);
1396 if ((pk->dsa = DSA_new()) == NULL)
1397 fatal("key_demote: DSA_new failed");
1398 if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL)
1399 fatal("key_demote: BN_dup failed");
1400 if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL)
1401 fatal("key_demote: BN_dup failed");
1402 if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL)
1403 fatal("key_demote: BN_dup failed");
1404 if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL)
1405 fatal("key_demote: BN_dup failed");
1408 fatal("key_free: bad key type %d", k->type);
1416 key_is_cert(const Key *k)
1421 case KEY_RSA_CERT_V00:
1422 case KEY_DSA_CERT_V00:
1431 /* Return the cert-less equivalent to a certified key type */
1433 key_type_plain(int type)
1436 case KEY_RSA_CERT_V00:
1439 case KEY_DSA_CERT_V00:
1447 /* Convert a KEY_RSA or KEY_DSA to their _CERT equivalent */
1449 key_to_certified(Key *k, int legacy)
1453 k->cert = cert_new();
1454 k->type = legacy ? KEY_RSA_CERT_V00 : KEY_RSA_CERT;
1457 k->cert = cert_new();
1458 k->type = legacy ? KEY_DSA_CERT_V00 : KEY_DSA_CERT;
1461 error("%s: key has incorrect type %s", __func__, key_type(k));
1466 /* Convert a KEY_RSA_CERT or KEY_DSA_CERT to their raw key equivalent */
1468 key_drop_cert(Key *k)
1471 case KEY_RSA_CERT_V00:
1476 case KEY_DSA_CERT_V00:
1482 error("%s: key has incorrect type %s", __func__, key_type(k));
1487 /* Sign a KEY_RSA_CERT or KEY_DSA_CERT, (re-)generating the signed certblob */
1489 key_certify(Key *k, Key *ca)
1492 u_char *ca_blob, *sig_blob, nonce[32];
1493 u_int i, ca_len, sig_len;
1495 if (k->cert == NULL) {
1496 error("%s: key lacks cert info", __func__);
1500 if (!key_is_cert(k)) {
1501 error("%s: certificate has unknown type %d", __func__,
1506 if (ca->type != KEY_RSA && ca->type != KEY_DSA) {
1507 error("%s: CA key has unsupported type %s", __func__,
1512 key_to_blob(ca, &ca_blob, &ca_len);
1514 buffer_clear(&k->cert->certblob);
1515 buffer_put_cstring(&k->cert->certblob, key_ssh_name(k));
1517 /* -v01 certs put nonce first */
1518 if (k->type == KEY_DSA_CERT || k->type == KEY_RSA_CERT) {
1519 arc4random_buf(&nonce, sizeof(nonce));
1520 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce));
1524 case KEY_DSA_CERT_V00:
1526 buffer_put_bignum2(&k->cert->certblob, k->dsa->p);
1527 buffer_put_bignum2(&k->cert->certblob, k->dsa->q);
1528 buffer_put_bignum2(&k->cert->certblob, k->dsa->g);
1529 buffer_put_bignum2(&k->cert->certblob, k->dsa->pub_key);
1531 case KEY_RSA_CERT_V00:
1533 buffer_put_bignum2(&k->cert->certblob, k->rsa->e);
1534 buffer_put_bignum2(&k->cert->certblob, k->rsa->n);
1537 error("%s: key has incorrect type %s", __func__, key_type(k));
1538 buffer_clear(&k->cert->certblob);
1543 /* -v01 certs have a serial number next */
1544 if (k->type == KEY_DSA_CERT || k->type == KEY_RSA_CERT)
1545 buffer_put_int64(&k->cert->certblob, k->cert->serial);
1547 buffer_put_int(&k->cert->certblob, k->cert->type);
1548 buffer_put_cstring(&k->cert->certblob, k->cert->key_id);
1550 buffer_init(&principals);
1551 for (i = 0; i < k->cert->nprincipals; i++)
1552 buffer_put_cstring(&principals, k->cert->principals[i]);
1553 buffer_put_string(&k->cert->certblob, buffer_ptr(&principals),
1554 buffer_len(&principals));
1555 buffer_free(&principals);
1557 buffer_put_int64(&k->cert->certblob, k->cert->valid_after);
1558 buffer_put_int64(&k->cert->certblob, k->cert->valid_before);
1559 buffer_put_string(&k->cert->certblob,
1560 buffer_ptr(&k->cert->critical), buffer_len(&k->cert->critical));
1562 /* -v01 certs have non-critical options here */
1563 if (k->type == KEY_DSA_CERT || k->type == KEY_RSA_CERT) {
1564 buffer_put_string(&k->cert->certblob,
1565 buffer_ptr(&k->cert->extensions),
1566 buffer_len(&k->cert->extensions));
1569 /* -v00 certs put the nonce at the end */
1570 if (k->type == KEY_DSA_CERT_V00 || k->type == KEY_RSA_CERT_V00)
1571 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce));
1573 buffer_put_string(&k->cert->certblob, NULL, 0); /* reserved */
1574 buffer_put_string(&k->cert->certblob, ca_blob, ca_len);
1577 /* Sign the whole mess */
1578 if (key_sign(ca, &sig_blob, &sig_len, buffer_ptr(&k->cert->certblob),
1579 buffer_len(&k->cert->certblob)) != 0) {
1580 error("%s: signature operation failed", __func__);
1581 buffer_clear(&k->cert->certblob);
1584 /* Append signature and we are done */
1585 buffer_put_string(&k->cert->certblob, sig_blob, sig_len);
1592 key_cert_check_authority(const Key *k, int want_host, int require_principal,
1593 const char *name, const char **reason)
1595 u_int i, principal_matches;
1596 time_t now = time(NULL);
1599 if (k->cert->type != SSH2_CERT_TYPE_HOST) {
1600 *reason = "Certificate invalid: not a host certificate";
1604 if (k->cert->type != SSH2_CERT_TYPE_USER) {
1605 *reason = "Certificate invalid: not a user certificate";
1610 error("%s: system clock lies before epoch", __func__);
1611 *reason = "Certificate invalid: not yet valid";
1614 if ((u_int64_t)now < k->cert->valid_after) {
1615 *reason = "Certificate invalid: not yet valid";
1618 if ((u_int64_t)now >= k->cert->valid_before) {
1619 *reason = "Certificate invalid: expired";
1622 if (k->cert->nprincipals == 0) {
1623 if (require_principal) {
1624 *reason = "Certificate lacks principal list";
1627 } else if (name != NULL) {
1628 principal_matches = 0;
1629 for (i = 0; i < k->cert->nprincipals; i++) {
1630 if (strcmp(name, k->cert->principals[i]) == 0) {
1631 principal_matches = 1;
1635 if (!principal_matches) {
1636 *reason = "Certificate invalid: name is not a listed "
1645 key_cert_is_legacy(Key *k)
1648 case KEY_DSA_CERT_V00:
1649 case KEY_RSA_CERT_V00: