1 /* $OpenBSD: key.c,v 1.85 2010/03/04 01:44:57 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>
57 static struct KeyCert *
62 cert = xcalloc(1, sizeof(*cert));
63 buffer_init(&cert->certblob);
64 buffer_init(&cert->constraints);
66 cert->principals = NULL;
67 cert->signature_key = NULL;
77 k = xcalloc(1, sizeof(*k));
86 if ((rsa = RSA_new()) == NULL)
87 fatal("key_new: RSA_new failed");
88 if ((rsa->n = BN_new()) == NULL)
89 fatal("key_new: BN_new failed");
90 if ((rsa->e = BN_new()) == NULL)
91 fatal("key_new: BN_new failed");
96 if ((dsa = DSA_new()) == NULL)
97 fatal("key_new: DSA_new failed");
98 if ((dsa->p = BN_new()) == NULL)
99 fatal("key_new: BN_new failed");
100 if ((dsa->q = BN_new()) == NULL)
101 fatal("key_new: BN_new failed");
102 if ((dsa->g = BN_new()) == NULL)
103 fatal("key_new: BN_new failed");
104 if ((dsa->pub_key = BN_new()) == NULL)
105 fatal("key_new: BN_new failed");
111 fatal("key_new: bad key type %d", k->type);
116 k->cert = cert_new();
122 key_add_private(Key *k)
128 if ((k->rsa->d = BN_new()) == NULL)
129 fatal("key_new_private: BN_new failed");
130 if ((k->rsa->iqmp = BN_new()) == NULL)
131 fatal("key_new_private: BN_new failed");
132 if ((k->rsa->q = BN_new()) == NULL)
133 fatal("key_new_private: BN_new failed");
134 if ((k->rsa->p = BN_new()) == NULL)
135 fatal("key_new_private: BN_new failed");
136 if ((k->rsa->dmq1 = BN_new()) == NULL)
137 fatal("key_new_private: BN_new failed");
138 if ((k->rsa->dmp1 = BN_new()) == NULL)
139 fatal("key_new_private: BN_new failed");
143 if ((k->dsa->priv_key = BN_new()) == NULL)
144 fatal("key_new_private: BN_new failed");
154 key_new_private(int type)
156 Key *k = key_new(type);
163 cert_free(struct KeyCert *cert)
167 buffer_free(&cert->certblob);
168 buffer_free(&cert->constraints);
169 if (cert->key_id != NULL)
171 for (i = 0; i < cert->nprincipals; i++)
172 xfree(cert->principals[i]);
173 if (cert->principals != NULL)
174 xfree(cert->principals);
175 if (cert->signature_key != NULL)
176 key_free(cert->signature_key);
183 fatal("key_free: key is NULL");
201 fatal("key_free: bad key type %d", k->type);
204 if (key_is_cert(k)) {
214 cert_compare(struct KeyCert *a, struct KeyCert *b)
216 if (a == NULL && b == NULL)
218 if (a == NULL || b == NULL)
220 if (buffer_len(&a->certblob) != buffer_len(&b->certblob))
222 if (memcmp(buffer_ptr(&a->certblob), buffer_ptr(&b->certblob),
223 buffer_len(&a->certblob)) != 0)
229 * Compare public portions of key only, allowing comparisons between
230 * certificates and plain keys too.
233 key_equal_public(const Key *a, const Key *b)
235 if (a == NULL || b == NULL ||
236 key_type_plain(a->type) != key_type_plain(b->type))
243 return a->rsa != NULL && b->rsa != NULL &&
244 BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
245 BN_cmp(a->rsa->n, b->rsa->n) == 0;
248 return a->dsa != NULL && b->dsa != NULL &&
249 BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
250 BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
251 BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
252 BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
254 fatal("key_equal: bad key type %d", a->type);
260 key_equal(const Key *a, const Key *b)
262 if (a == NULL || b == NULL || a->type != b->type)
264 if (key_is_cert(a)) {
265 if (!cert_compare(a->cert, b->cert))
268 return key_equal_public(a, b);
272 key_fingerprint_raw(Key *k, enum fp_type dgst_type, u_int *dgst_raw_length)
274 const EVP_MD *md = NULL;
277 u_char *retval = NULL;
279 int nlen, elen, otype;
281 *dgst_raw_length = 0;
291 fatal("key_fingerprint_raw: bad digest type %d",
296 nlen = BN_num_bytes(k->rsa->n);
297 elen = BN_num_bytes(k->rsa->e);
300 BN_bn2bin(k->rsa->n, blob);
301 BN_bn2bin(k->rsa->e, blob + nlen);
305 key_to_blob(k, &blob, &len);
309 /* We want a fingerprint of the _key_ not of the cert */
311 k->type = key_type_plain(k->type);
312 key_to_blob(k, &blob, &len);
318 fatal("key_fingerprint_raw: bad key type %d", k->type);
322 retval = xmalloc(EVP_MAX_MD_SIZE);
323 EVP_DigestInit(&ctx, md);
324 EVP_DigestUpdate(&ctx, blob, len);
325 EVP_DigestFinal(&ctx, retval, dgst_raw_length);
326 memset(blob, 0, len);
329 fatal("key_fingerprint_raw: blob is null");
335 key_fingerprint_hex(u_char *dgst_raw, u_int dgst_raw_len)
340 retval = xcalloc(1, dgst_raw_len * 3 + 1);
341 for (i = 0; i < dgst_raw_len; i++) {
343 snprintf(hex, sizeof(hex), "%02x:", dgst_raw[i]);
344 strlcat(retval, hex, dgst_raw_len * 3 + 1);
347 /* Remove the trailing ':' character */
348 retval[(dgst_raw_len * 3) - 1] = '\0';
353 key_fingerprint_bubblebabble(u_char *dgst_raw, u_int dgst_raw_len)
355 char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
356 char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
357 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
358 u_int i, j = 0, rounds, seed = 1;
361 rounds = (dgst_raw_len / 2) + 1;
362 retval = xcalloc((rounds * 6), sizeof(char));
364 for (i = 0; i < rounds; i++) {
365 u_int idx0, idx1, idx2, idx3, idx4;
366 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) {
367 idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) +
369 idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15;
370 idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) +
372 retval[j++] = vowels[idx0];
373 retval[j++] = consonants[idx1];
374 retval[j++] = vowels[idx2];
375 if ((i + 1) < rounds) {
376 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15;
377 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15;
378 retval[j++] = consonants[idx3];
380 retval[j++] = consonants[idx4];
382 ((((u_int)(dgst_raw[2 * i])) * 7) +
383 ((u_int)(dgst_raw[(2 * i) + 1])))) % 36;
389 retval[j++] = vowels[idx0];
390 retval[j++] = consonants[idx1];
391 retval[j++] = vowels[idx2];
400 * Draw an ASCII-Art representing the fingerprint so human brain can
401 * profit from its built-in pattern recognition ability.
402 * This technique is called "random art" and can be found in some
403 * scientific publications like this original paper:
405 * "Hash Visualization: a New Technique to improve Real-World Security",
406 * Perrig A. and Song D., 1999, International Workshop on Cryptographic
407 * Techniques and E-Commerce (CrypTEC '99)
408 * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
410 * The subject came up in a talk by Dan Kaminsky, too.
412 * If you see the picture is different, the key is different.
413 * If the picture looks the same, you still know nothing.
415 * The algorithm used here is a worm crawling over a discrete plane,
416 * leaving a trace (augmenting the field) everywhere it goes.
417 * Movement is taken from dgst_raw 2bit-wise. Bumping into walls
418 * makes the respective movement vector be ignored for this turn.
419 * Graphs are not unambiguous, because circles in graphs can be
420 * walked in either direction.
424 * Field sizes for the random art. Have to be odd, so the starting point
425 * can be in the exact middle of the picture, and FLDBASE should be >=8 .
426 * Else pictures would be too dense, and drawing the frame would
427 * fail, too, because the key type would not fit in anymore.
430 #define FLDSIZE_Y (FLDBASE + 1)
431 #define FLDSIZE_X (FLDBASE * 2 + 1)
433 key_fingerprint_randomart(u_char *dgst_raw, u_int dgst_raw_len, const Key *k)
436 * Chars to be used after each other every time the worm
437 * intersects with itself. Matter of taste.
439 char *augmentation_string = " .o+=*BOX@%&#/^SE";
441 u_char field[FLDSIZE_X][FLDSIZE_Y];
444 size_t len = strlen(augmentation_string) - 1;
446 retval = xcalloc(1, (FLDSIZE_X + 3) * (FLDSIZE_Y + 2));
448 /* initialize field */
449 memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char));
453 /* process raw key */
454 for (i = 0; i < dgst_raw_len; i++) {
456 /* each byte conveys four 2-bit move commands */
458 for (b = 0; b < 4; b++) {
459 /* evaluate 2 bit, rest is shifted later */
460 x += (input & 0x1) ? 1 : -1;
461 y += (input & 0x2) ? 1 : -1;
463 /* assure we are still in bounds */
466 x = MIN(x, FLDSIZE_X - 1);
467 y = MIN(y, FLDSIZE_Y - 1);
469 /* augment the field */
470 if (field[x][y] < len - 2)
476 /* mark starting point and end point*/
477 field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1;
481 snprintf(retval, FLDSIZE_X, "+--[%4s %4u]", key_type(k), key_size(k));
482 p = strchr(retval, '\0');
484 /* output upper border */
485 for (i = p - retval - 1; i < FLDSIZE_X; i++)
491 for (y = 0; y < FLDSIZE_Y; y++) {
493 for (x = 0; x < FLDSIZE_X; x++)
494 *p++ = augmentation_string[MIN(field[x][y], len)];
499 /* output lower border */
501 for (i = 0; i < FLDSIZE_X; i++)
509 key_fingerprint(Key *k, enum fp_type dgst_type, enum fp_rep dgst_rep)
515 dgst_raw = key_fingerprint_raw(k, dgst_type, &dgst_raw_len);
517 fatal("key_fingerprint: null from key_fingerprint_raw()");
520 retval = key_fingerprint_hex(dgst_raw, dgst_raw_len);
522 case SSH_FP_BUBBLEBABBLE:
523 retval = key_fingerprint_bubblebabble(dgst_raw, dgst_raw_len);
525 case SSH_FP_RANDOMART:
526 retval = key_fingerprint_randomart(dgst_raw, dgst_raw_len, k);
529 fatal("key_fingerprint: bad digest representation %d",
533 memset(dgst_raw, 0, dgst_raw_len);
539 * Reads a multiple-precision integer in decimal from the buffer, and advances
540 * the pointer. The integer must already be initialized. This function is
541 * permitted to modify the buffer. This leaves *cpp to point just beyond the
542 * last processed (and maybe modified) character. Note that this may modify
543 * the buffer containing the number.
546 read_bignum(char **cpp, BIGNUM * value)
551 /* Skip any leading whitespace. */
552 for (; *cp == ' ' || *cp == '\t'; cp++)
555 /* Check that it begins with a decimal digit. */
556 if (*cp < '0' || *cp > '9')
559 /* Save starting position. */
562 /* Move forward until all decimal digits skipped. */
563 for (; *cp >= '0' && *cp <= '9'; cp++)
566 /* Save the old terminating character, and replace it by \0. */
570 /* Parse the number. */
571 if (BN_dec2bn(&value, *cpp) == 0)
574 /* Restore old terminating character. */
577 /* Move beyond the number and return success. */
583 write_bignum(FILE *f, BIGNUM *num)
585 char *buf = BN_bn2dec(num);
587 error("write_bignum: BN_bn2dec() failed");
590 fprintf(f, " %s", buf);
595 /* returns 1 ok, -1 error */
597 key_read(Key *ret, char **cpp)
610 /* Get number of bits. */
611 if (*cp < '0' || *cp > '9')
612 return -1; /* Bad bit count... */
613 for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
614 bits = 10 * bits + *cp - '0';
618 /* Get public exponent, public modulus. */
619 if (!read_bignum(cpp, ret->rsa->e))
621 if (!read_bignum(cpp, ret->rsa->n))
623 /* validate the claimed number of bits */
624 if ((u_int)BN_num_bits(ret->rsa->n) != bits) {
625 verbose("key_read: claimed key size %d does not match "
626 "actual %d", bits, BN_num_bits(ret->rsa->n));
636 space = strchr(cp, ' ');
638 debug3("key_read: missing whitespace");
642 type = key_type_from_name(cp);
644 if (type == KEY_UNSPEC) {
645 debug3("key_read: missing keytype");
650 debug3("key_read: short string");
653 if (ret->type == KEY_UNSPEC) {
655 } else if (ret->type != type) {
656 /* is a key, but different type */
657 debug3("key_read: type mismatch");
662 n = uudecode(cp, blob, len);
664 error("key_read: uudecode %s failed", cp);
668 k = key_from_blob(blob, (u_int)n);
671 error("key_read: key_from_blob %s failed", cp);
674 if (k->type != type) {
675 error("key_read: type mismatch: encoding error");
680 if (key_is_cert(ret)) {
681 if (!key_is_cert(k)) {
682 error("key_read: loaded key is not a cert");
686 if (ret->cert != NULL)
687 cert_free(ret->cert);
691 if (key_type_plain(ret->type) == KEY_RSA) {
692 if (ret->rsa != NULL)
697 RSA_print_fp(stderr, ret->rsa, 8);
700 if (key_type_plain(ret->type) == KEY_DSA) {
701 if (ret->dsa != NULL)
706 DSA_print_fp(stderr, ret->dsa, 8);
714 /* advance cp: skip whitespace and data */
715 while (*cp == ' ' || *cp == '\t')
717 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
722 fatal("key_read: bad key type: %d", ret->type);
729 key_write(const Key *key, FILE *f)
736 if (key_is_cert(key)) {
737 if (key->cert == NULL) {
738 error("%s: no cert data", __func__);
741 if (buffer_len(&key->cert->certblob) == 0) {
742 error("%s: no signed certificate blob", __func__);
749 if (key->rsa == NULL)
751 /* size of modulus 'n' */
752 bits = BN_num_bits(key->rsa->n);
753 fprintf(f, "%u", bits);
754 if (write_bignum(f, key->rsa->e) &&
755 write_bignum(f, key->rsa->n))
757 error("key_write: failed for RSA key");
761 if (key->dsa == NULL)
766 if (key->rsa == NULL)
773 key_to_blob(key, &blob, &len);
775 n = uuencode(blob, len, uu, 2*len);
777 fprintf(f, "%s %s", key_ssh_name(key), uu);
787 key_type(const Key *k)
805 key_ssh_name(const Key *k)
813 return "ssh-rsa-cert-v00@openssh.com";
815 return "ssh-dss-cert-v00@openssh.com";
817 return "ssh-unknown";
821 key_size(const Key *k)
827 return BN_num_bits(k->rsa->n);
830 return BN_num_bits(k->dsa->p);
836 rsa_generate_private_key(u_int bits)
840 private = RSA_generate_key(bits, RSA_F4, NULL, NULL);
842 fatal("rsa_generate_private_key: key generation failed.");
847 dsa_generate_private_key(u_int bits)
849 DSA *private = DSA_generate_parameters(bits, NULL, 0, NULL, NULL, NULL, NULL);
852 fatal("dsa_generate_private_key: DSA_generate_parameters failed");
853 if (!DSA_generate_key(private))
854 fatal("dsa_generate_private_key: DSA_generate_key failed.");
856 fatal("dsa_generate_private_key: NULL.");
861 key_generate(int type, u_int bits)
863 Key *k = key_new(KEY_UNSPEC);
866 k->dsa = dsa_generate_private_key(bits);
870 k->rsa = rsa_generate_private_key(bits);
874 fatal("key_generate: cert keys cannot be generated directly");
876 fatal("key_generate: unknown type %d", type);
883 key_cert_copy(const Key *from_key, struct Key *to_key)
886 const struct KeyCert *from;
889 if (to_key->cert != NULL) {
890 cert_free(to_key->cert);
894 if ((from = from_key->cert) == NULL)
897 to = to_key->cert = cert_new();
899 buffer_append(&to->certblob, buffer_ptr(&from->certblob),
900 buffer_len(&from->certblob));
902 buffer_append(&to->constraints, buffer_ptr(&from->constraints),
903 buffer_len(&from->constraints));
905 to->type = from->type;
906 to->key_id = from->key_id == NULL ? NULL : xstrdup(from->key_id);
907 to->valid_after = from->valid_after;
908 to->valid_before = from->valid_before;
909 to->signature_key = from->signature_key == NULL ?
910 NULL : key_from_private(from->signature_key);
912 to->nprincipals = from->nprincipals;
913 if (to->nprincipals > CERT_MAX_PRINCIPALS)
914 fatal("%s: nprincipals (%u) > CERT_MAX_PRINCIPALS (%u)",
915 __func__, to->nprincipals, CERT_MAX_PRINCIPALS);
916 if (to->nprincipals > 0) {
917 to->principals = xcalloc(from->nprincipals,
918 sizeof(*to->principals));
919 for (i = 0; i < to->nprincipals; i++)
920 to->principals[i] = xstrdup(from->principals[i]);
925 key_from_private(const Key *k)
931 n = key_new(k->type);
932 if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) ||
933 (BN_copy(n->dsa->q, k->dsa->q) == NULL) ||
934 (BN_copy(n->dsa->g, k->dsa->g) == NULL) ||
935 (BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL))
936 fatal("key_from_private: BN_copy failed");
941 n = key_new(k->type);
942 if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) ||
943 (BN_copy(n->rsa->e, k->rsa->e) == NULL))
944 fatal("key_from_private: BN_copy failed");
947 fatal("key_from_private: unknown type %d", k->type);
956 key_type_from_name(char *name)
958 if (strcmp(name, "rsa1") == 0) {
960 } else if (strcmp(name, "rsa") == 0) {
962 } else if (strcmp(name, "dsa") == 0) {
964 } else if (strcmp(name, "ssh-rsa") == 0) {
966 } else if (strcmp(name, "ssh-dss") == 0) {
968 } else if (strcmp(name, "ssh-rsa-cert-v00@openssh.com") == 0) {
970 } else if (strcmp(name, "ssh-dss-cert-v00@openssh.com") == 0) {
973 debug2("key_type_from_name: unknown key type '%s'", name);
978 key_names_valid2(const char *names)
982 if (names == NULL || strcmp(names, "") == 0)
984 s = cp = xstrdup(names);
985 for ((p = strsep(&cp, ",")); p && *p != '\0';
986 (p = strsep(&cp, ","))) {
987 switch (key_type_from_name(p)) {
994 debug3("key names ok: [%s]", names);
1000 cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
1002 u_char *principals, *constraints, *sig_key, *sig;
1003 u_int signed_len, plen, clen, sklen, slen, kidlen;
1010 /* Copy the entire key blob for verification and later serialisation */
1011 buffer_append(&key->cert->certblob, blob, blen);
1013 principals = constraints = sig_key = sig = NULL;
1014 if (buffer_get_int_ret(&key->cert->type, b) != 0 ||
1015 (key->cert->key_id = buffer_get_string_ret(b, &kidlen)) == NULL ||
1016 (principals = buffer_get_string_ret(b, &plen)) == NULL ||
1017 buffer_get_int64_ret(&key->cert->valid_after, b) != 0 ||
1018 buffer_get_int64_ret(&key->cert->valid_before, b) != 0 ||
1019 (constraints = buffer_get_string_ret(b, &clen)) == NULL ||
1020 /* skip nonce */ buffer_get_string_ptr_ret(b, NULL) == NULL ||
1021 /* skip reserved */ buffer_get_string_ptr_ret(b, NULL) == NULL ||
1022 (sig_key = buffer_get_string_ret(b, &sklen)) == NULL) {
1023 error("%s: parse error", __func__);
1027 if (kidlen != strlen(key->cert->key_id)) {
1028 error("%s: key ID contains \\0 character", __func__);
1032 /* Signature is left in the buffer so we can calculate this length */
1033 signed_len = buffer_len(&key->cert->certblob) - buffer_len(b);
1035 if ((sig = buffer_get_string_ret(b, &slen)) == NULL) {
1036 error("%s: parse error", __func__);
1040 if (key->cert->type != SSH2_CERT_TYPE_USER &&
1041 key->cert->type != SSH2_CERT_TYPE_HOST) {
1042 error("Unknown certificate type %u", key->cert->type);
1046 buffer_append(&tmp, principals, plen);
1047 while (buffer_len(&tmp) > 0) {
1048 if (key->cert->nprincipals >= CERT_MAX_PRINCIPALS) {
1049 error("%s: Too many principals", __func__);
1052 if ((principal = buffer_get_string_ret(&tmp, &plen)) == NULL) {
1053 error("%s: Principals data invalid", __func__);
1056 if (strlen(principal) != plen) {
1057 error("%s: Principal contains \\0 character",
1061 key->cert->principals = xrealloc(key->cert->principals,
1062 key->cert->nprincipals + 1, sizeof(*key->cert->principals));
1063 key->cert->principals[key->cert->nprincipals++] = principal;
1068 buffer_append(&key->cert->constraints, constraints, clen);
1069 buffer_append(&tmp, constraints, clen);
1070 /* validate structure */
1071 while (buffer_len(&tmp) != 0) {
1072 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL ||
1073 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) {
1074 error("%s: Constraints data invalid", __func__);
1080 if ((key->cert->signature_key = key_from_blob(sig_key,
1082 error("%s: Signature key invalid", __func__);
1085 if (key->cert->signature_key->type != KEY_RSA &&
1086 key->cert->signature_key->type != KEY_DSA) {
1087 error("%s: Invalid signature key type %s (%d)", __func__,
1088 key_type(key->cert->signature_key),
1089 key->cert->signature_key->type);
1093 switch (key_verify(key->cert->signature_key, sig, slen,
1094 buffer_ptr(&key->cert->certblob), signed_len)) {
1097 break; /* Good signature */
1099 error("%s: Invalid signature on certificate", __func__);
1102 error("%s: Certificate signature verification failed",
1109 if (principals != NULL)
1111 if (constraints != NULL)
1113 if (sig_key != NULL)
1121 key_from_blob(const u_char *blob, u_int blen)
1129 dump_base64(stderr, blob, blen);
1132 buffer_append(&b, blob, blen);
1133 if ((ktype = buffer_get_string_ret(&b, NULL)) == NULL) {
1134 error("key_from_blob: can't read key type");
1138 type = key_type_from_name(ktype);
1143 key = key_new(type);
1144 if (buffer_get_bignum2_ret(&b, key->rsa->e) == -1 ||
1145 buffer_get_bignum2_ret(&b, key->rsa->n) == -1) {
1146 error("key_from_blob: can't read rsa key");
1153 RSA_print_fp(stderr, key->rsa, 8);
1158 key = key_new(type);
1159 if (buffer_get_bignum2_ret(&b, key->dsa->p) == -1 ||
1160 buffer_get_bignum2_ret(&b, key->dsa->q) == -1 ||
1161 buffer_get_bignum2_ret(&b, key->dsa->g) == -1 ||
1162 buffer_get_bignum2_ret(&b, key->dsa->pub_key) == -1) {
1163 error("key_from_blob: can't read dsa key");
1167 DSA_print_fp(stderr, key->dsa, 8);
1171 key = key_new(type);
1174 error("key_from_blob: cannot handle type %s", ktype);
1177 if (key_is_cert(key) && cert_parse(&b, key, blob, blen) == -1) {
1178 error("key_from_blob: can't parse cert data");
1181 rlen = buffer_len(&b);
1182 if (key != NULL && rlen != 0)
1183 error("key_from_blob: remaining bytes in key blob %d", rlen);
1192 key_to_blob(const Key *key, u_char **blobp, u_int *lenp)
1198 error("key_to_blob: key == NULL");
1202 switch (key->type) {
1205 /* Use the existing blob */
1206 buffer_append(&b, buffer_ptr(&key->cert->certblob),
1207 buffer_len(&key->cert->certblob));
1210 buffer_put_cstring(&b, key_ssh_name(key));
1211 buffer_put_bignum2(&b, key->dsa->p);
1212 buffer_put_bignum2(&b, key->dsa->q);
1213 buffer_put_bignum2(&b, key->dsa->g);
1214 buffer_put_bignum2(&b, key->dsa->pub_key);
1217 buffer_put_cstring(&b, key_ssh_name(key));
1218 buffer_put_bignum2(&b, key->rsa->e);
1219 buffer_put_bignum2(&b, key->rsa->n);
1222 error("key_to_blob: unsupported key type %d", key->type);
1226 len = buffer_len(&b);
1229 if (blobp != NULL) {
1230 *blobp = xmalloc(len);
1231 memcpy(*blobp, buffer_ptr(&b), len);
1233 memset(buffer_ptr(&b), 0, len);
1241 u_char **sigp, u_int *lenp,
1242 const u_char *data, u_int datalen)
1244 switch (key->type) {
1247 return ssh_dss_sign(key, sigp, lenp, data, datalen);
1250 return ssh_rsa_sign(key, sigp, lenp, data, datalen);
1252 error("key_sign: invalid key type %d", key->type);
1258 * key_verify returns 1 for a correct signature, 0 for an incorrect signature
1264 const u_char *signature, u_int signaturelen,
1265 const u_char *data, u_int datalen)
1267 if (signaturelen == 0)
1270 switch (key->type) {
1273 return ssh_dss_verify(key, signature, signaturelen, data, datalen);
1276 return ssh_rsa_verify(key, signature, signaturelen, data, datalen);
1278 error("key_verify: invalid key type %d", key->type);
1283 /* Converts a private to a public key */
1285 key_demote(const Key *k)
1289 pk = xcalloc(1, sizeof(*pk));
1291 pk->flags = k->flags;
1297 key_cert_copy(k, pk);
1301 if ((pk->rsa = RSA_new()) == NULL)
1302 fatal("key_demote: RSA_new failed");
1303 if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL)
1304 fatal("key_demote: BN_dup failed");
1305 if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL)
1306 fatal("key_demote: BN_dup failed");
1309 key_cert_copy(k, pk);
1312 if ((pk->dsa = DSA_new()) == NULL)
1313 fatal("key_demote: DSA_new failed");
1314 if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL)
1315 fatal("key_demote: BN_dup failed");
1316 if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL)
1317 fatal("key_demote: BN_dup failed");
1318 if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL)
1319 fatal("key_demote: BN_dup failed");
1320 if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL)
1321 fatal("key_demote: BN_dup failed");
1324 fatal("key_free: bad key type %d", k->type);
1332 key_is_cert(const Key *k)
1335 (k->type == KEY_RSA_CERT || k->type == KEY_DSA_CERT);
1338 /* Return the cert-less equivalent to a certified key type */
1340 key_type_plain(int type)
1352 /* Convert a KEY_RSA or KEY_DSA to their _CERT equivalent */
1354 key_to_certified(Key *k)
1358 k->cert = cert_new();
1359 k->type = KEY_RSA_CERT;
1362 k->cert = cert_new();
1363 k->type = KEY_DSA_CERT;
1366 error("%s: key has incorrect type %s", __func__, key_type(k));
1371 /* Convert a KEY_RSA_CERT or KEY_DSA_CERT to their raw key equivalent */
1373 key_drop_cert(Key *k)
1385 error("%s: key has incorrect type %s", __func__, key_type(k));
1390 /* Sign a KEY_RSA_CERT or KEY_DSA_CERT, (re-)generating the signed certblob */
1392 key_certify(Key *k, Key *ca)
1395 u_char *ca_blob, *sig_blob, nonce[32];
1396 u_int i, ca_len, sig_len;
1398 if (k->cert == NULL) {
1399 error("%s: key lacks cert info", __func__);
1403 if (!key_is_cert(k)) {
1404 error("%s: certificate has unknown type %d", __func__,
1409 if (ca->type != KEY_RSA && ca->type != KEY_DSA) {
1410 error("%s: CA key has unsupported type %s", __func__,
1415 key_to_blob(ca, &ca_blob, &ca_len);
1417 buffer_clear(&k->cert->certblob);
1418 buffer_put_cstring(&k->cert->certblob, key_ssh_name(k));
1422 buffer_put_bignum2(&k->cert->certblob, k->dsa->p);
1423 buffer_put_bignum2(&k->cert->certblob, k->dsa->q);
1424 buffer_put_bignum2(&k->cert->certblob, k->dsa->g);
1425 buffer_put_bignum2(&k->cert->certblob, k->dsa->pub_key);
1428 buffer_put_bignum2(&k->cert->certblob, k->rsa->e);
1429 buffer_put_bignum2(&k->cert->certblob, k->rsa->n);
1432 error("%s: key has incorrect type %s", __func__, key_type(k));
1433 buffer_clear(&k->cert->certblob);
1438 buffer_put_int(&k->cert->certblob, k->cert->type);
1439 buffer_put_cstring(&k->cert->certblob, k->cert->key_id);
1441 buffer_init(&principals);
1442 for (i = 0; i < k->cert->nprincipals; i++)
1443 buffer_put_cstring(&principals, k->cert->principals[i]);
1444 buffer_put_string(&k->cert->certblob, buffer_ptr(&principals),
1445 buffer_len(&principals));
1446 buffer_free(&principals);
1448 buffer_put_int64(&k->cert->certblob, k->cert->valid_after);
1449 buffer_put_int64(&k->cert->certblob, k->cert->valid_before);
1450 buffer_put_string(&k->cert->certblob,
1451 buffer_ptr(&k->cert->constraints),
1452 buffer_len(&k->cert->constraints));
1454 arc4random_buf(&nonce, sizeof(nonce));
1455 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce));
1456 buffer_put_string(&k->cert->certblob, NULL, 0); /* reserved */
1457 buffer_put_string(&k->cert->certblob, ca_blob, ca_len);
1460 /* Sign the whole mess */
1461 if (key_sign(ca, &sig_blob, &sig_len, buffer_ptr(&k->cert->certblob),
1462 buffer_len(&k->cert->certblob)) != 0) {
1463 error("%s: signature operation failed", __func__);
1464 buffer_clear(&k->cert->certblob);
1467 /* Append signature and we are done */
1468 buffer_put_string(&k->cert->certblob, sig_blob, sig_len);
1475 key_cert_check_authority(const Key *k, int want_host, int require_principal,
1476 const char *name, const char **reason)
1478 u_int i, principal_matches;
1479 time_t now = time(NULL);
1482 if (k->cert->type != SSH2_CERT_TYPE_HOST) {
1483 *reason = "Certificate invalid: not a host certificate";
1487 if (k->cert->type != SSH2_CERT_TYPE_USER) {
1488 *reason = "Certificate invalid: not a user certificate";
1493 error("%s: system clock lies before epoch", __func__);
1494 *reason = "Certificate invalid: not yet valid";
1497 if ((u_int64_t)now < k->cert->valid_after) {
1498 *reason = "Certificate invalid: not yet valid";
1501 if ((u_int64_t)now >= k->cert->valid_before) {
1502 *reason = "Certificate invalid: expired";
1505 if (k->cert->nprincipals == 0) {
1506 if (require_principal) {
1507 *reason = "Certificate lacks principal list";
1511 principal_matches = 0;
1512 for (i = 0; i < k->cert->nprincipals; i++) {
1513 if (strcmp(name, k->cert->principals[i]) == 0) {
1514 principal_matches = 1;
1518 if (!principal_matches) {
1519 *reason = "Certificate invalid: name is not a listed "