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- (tim) [openbsd-compat/glob.h] Remove sys/cdefs.h include that came with
[openssh-git.git] / key.c
blob196092de5c6b19330336f3f569f092b6ad5ac71f
1 /* $OpenBSD: key.c,v 1.93 2010/09/09 10:45:45 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
58 static struct KeyCert *
59 cert_new(void)
60 {
61 struct KeyCert *cert;
62
63 cert = xcalloc(1, sizeof(*cert));
64 buffer_init(&cert->certblob);
65 buffer_init(&cert->critical);
66 buffer_init(&cert->extensions);
67 cert->key_id = NULL;
68 cert->principals = NULL;
69 cert->signature_key = NULL;
70 return cert;
71 }
72
73 Key *
74 key_new(int type)
75 {
76 Key *k;
77 RSA *rsa;
78 DSA *dsa;
79 k = xcalloc(1, sizeof(*k));
80 k->type = type;
81 k->ecdsa = NULL;
82 k->ecdsa_nid = -1;
83 k->dsa = NULL;
84 k->rsa = NULL;
85 k->cert = NULL;
86 switch (k->type) {
87 case KEY_RSA1:
88 case KEY_RSA:
89 case KEY_RSA_CERT_V00:
90 case KEY_RSA_CERT:
91 if ((rsa = RSA_new()) == NULL)
92 fatal("key_new: RSA_new failed");
93 if ((rsa->n = BN_new()) == NULL)
94 fatal("key_new: BN_new failed");
95 if ((rsa->e = BN_new()) == NULL)
96 fatal("key_new: BN_new failed");
97 k->rsa = rsa;
98 break;
99 case KEY_DSA:
100 case KEY_DSA_CERT_V00:
101 case KEY_DSA_CERT:
102 if ((dsa = DSA_new()) == NULL)
103 fatal("key_new: DSA_new failed");
104 if ((dsa->p = BN_new()) == NULL)
105 fatal("key_new: BN_new failed");
106 if ((dsa->q = BN_new()) == NULL)
107 fatal("key_new: BN_new failed");
108 if ((dsa->g = BN_new()) == NULL)
109 fatal("key_new: BN_new failed");
110 if ((dsa->pub_key = BN_new()) == NULL)
111 fatal("key_new: BN_new failed");
112 k->dsa = dsa;
113 break;
114 #ifdef OPENSSL_HAS_ECC
115 case KEY_ECDSA:
116 case KEY_ECDSA_CERT:
117 /* Cannot do anything until we know the group */
118 break;
119 #endif
120 case KEY_UNSPEC:
121 break;
122 default:
123 fatal("key_new: bad key type %d", k->type);
124 break;
125 }
126
127 if (key_is_cert(k))
128 k->cert = cert_new();
129
130 return k;
131 }
132
133 void
134 key_add_private(Key *k)
135 {
136 switch (k->type) {
137 case KEY_RSA1:
138 case KEY_RSA:
139 case KEY_RSA_CERT_V00:
140 case KEY_RSA_CERT:
141 if ((k->rsa->d = BN_new()) == NULL)
142 fatal("key_new_private: BN_new failed");
143 if ((k->rsa->iqmp = BN_new()) == NULL)
144 fatal("key_new_private: BN_new failed");
145 if ((k->rsa->q = BN_new()) == NULL)
146 fatal("key_new_private: BN_new failed");
147 if ((k->rsa->p = BN_new()) == NULL)
148 fatal("key_new_private: BN_new failed");
149 if ((k->rsa->dmq1 = BN_new()) == NULL)
150 fatal("key_new_private: BN_new failed");
151 if ((k->rsa->dmp1 = BN_new()) == NULL)
152 fatal("key_new_private: BN_new failed");
153 break;
154 case KEY_DSA:
155 case KEY_DSA_CERT_V00:
156 case KEY_DSA_CERT:
157 if ((k->dsa->priv_key = BN_new()) == NULL)
158 fatal("key_new_private: BN_new failed");
159 break;
160 case KEY_ECDSA:
161 case KEY_ECDSA_CERT:
162 /* Cannot do anything until we know the group */
163 break;
164 case KEY_UNSPEC:
165 break;
166 default:
167 break;
168 }
169 }
170
171 Key *
172 key_new_private(int type)
173 {
174 Key *k = key_new(type);
175
176 key_add_private(k);
177 return k;
178 }
179
180 static void
181 cert_free(struct KeyCert *cert)
182 {
183 u_int i;
184
185 buffer_free(&cert->certblob);
186 buffer_free(&cert->critical);
187 buffer_free(&cert->extensions);
188 if (cert->key_id != NULL)
189 xfree(cert->key_id);
190 for (i = 0; i < cert->nprincipals; i++)
191 xfree(cert->principals[i]);
192 if (cert->principals != NULL)
193 xfree(cert->principals);
194 if (cert->signature_key != NULL)
195 key_free(cert->signature_key);
196 }
197
198 void
199 key_free(Key *k)
200 {
201 if (k == NULL)
202 fatal("key_free: key is NULL");
203 switch (k->type) {
204 case KEY_RSA1:
205 case KEY_RSA:
206 case KEY_RSA_CERT_V00:
207 case KEY_RSA_CERT:
208 if (k->rsa != NULL)
209 RSA_free(k->rsa);
210 k->rsa = NULL;
211 break;
212 case KEY_DSA:
213 case KEY_DSA_CERT_V00:
214 case KEY_DSA_CERT:
215 if (k->dsa != NULL)
216 DSA_free(k->dsa);
217 k->dsa = NULL;
218 break;
219 #ifdef OPENSSL_HAS_ECC
220 case KEY_ECDSA:
221 case KEY_ECDSA_CERT:
222 if (k->ecdsa != NULL)
223 EC_KEY_free(k->ecdsa);
224 k->ecdsa = NULL;
225 break;
226 #endif
227 case KEY_UNSPEC:
228 break;
229 default:
230 fatal("key_free: bad key type %d", k->type);
231 break;
232 }
233 if (key_is_cert(k)) {
234 if (k->cert != NULL)
235 cert_free(k->cert);
236 k->cert = NULL;
237 }
238
239 xfree(k);
240 }
241
242 static int
243 cert_compare(struct KeyCert *a, struct KeyCert *b)
244 {
245 if (a == NULL && b == NULL)
246 return 1;
247 if (a == NULL || b == NULL)
248 return 0;
249 if (buffer_len(&a->certblob) != buffer_len(&b->certblob))
250 return 0;
251 if (timingsafe_bcmp(buffer_ptr(&a->certblob), buffer_ptr(&b->certblob),
252 buffer_len(&a->certblob)) != 0)
253 return 0;
254 return 1;
255 }
256
257 /*
258 * Compare public portions of key only, allowing comparisons between
259 * certificates and plain keys too.
260 */
261 int
262 key_equal_public(const Key *a, const Key *b)
263 {
264 #ifdef OPENSSL_HAS_ECC
265 BN_CTX *bnctx;
266 #endif
267
268 if (a == NULL || b == NULL ||
269 key_type_plain(a->type) != key_type_plain(b->type))
270 return 0;
271
272 switch (a->type) {
273 case KEY_RSA1:
274 case KEY_RSA_CERT_V00:
275 case KEY_RSA_CERT:
276 case KEY_RSA:
277 return a->rsa != NULL && b->rsa != NULL &&
278 BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
279 BN_cmp(a->rsa->n, b->rsa->n) == 0;
280 case KEY_DSA_CERT_V00:
281 case KEY_DSA_CERT:
282 case KEY_DSA:
283 return a->dsa != NULL && b->dsa != NULL &&
284 BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
285 BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
286 BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
287 BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
288 #ifdef OPENSSL_HAS_ECC
289 case KEY_ECDSA_CERT:
290 case KEY_ECDSA:
291 if (a->ecdsa == NULL || b->ecdsa == NULL ||
292 EC_KEY_get0_public_key(a->ecdsa) == NULL ||
293 EC_KEY_get0_public_key(b->ecdsa) == NULL)
294 return 0;
295 if ((bnctx = BN_CTX_new()) == NULL)
296 fatal("%s: BN_CTX_new failed", __func__);
297 if (EC_GROUP_cmp(EC_KEY_get0_group(a->ecdsa),
298 EC_KEY_get0_group(b->ecdsa), bnctx) != 0 ||
299 EC_POINT_cmp(EC_KEY_get0_group(a->ecdsa),
300 EC_KEY_get0_public_key(a->ecdsa),
301 EC_KEY_get0_public_key(b->ecdsa), bnctx) != 0) {
302 BN_CTX_free(bnctx);
303 return 0;
304 }
305 BN_CTX_free(bnctx);
306 return 1;
307 #endif /* OPENSSL_HAS_ECC */
308 default:
309 fatal("key_equal: bad key type %d", a->type);
310 }
311 /* NOTREACHED */
312 }
313
314 int
315 key_equal(const Key *a, const Key *b)
316 {
317 if (a == NULL || b == NULL || a->type != b->type)
318 return 0;
319 if (key_is_cert(a)) {
320 if (!cert_compare(a->cert, b->cert))
321 return 0;
322 }
323 return key_equal_public(a, b);
324 }
325
326 u_char*
327 key_fingerprint_raw(Key *k, enum fp_type dgst_type, u_int *dgst_raw_length)
328 {
329 const EVP_MD *md = NULL;
330 EVP_MD_CTX ctx;
331 u_char *blob = NULL;
332 u_char *retval = NULL;
333 u_int len = 0;
334 int nlen, elen, otype;
335
336 *dgst_raw_length = 0;
337
338 switch (dgst_type) {
339 case SSH_FP_MD5:
340 md = EVP_md5();
341 break;
342 case SSH_FP_SHA1:
343 md = EVP_sha1();
344 break;
345 default:
346 fatal("key_fingerprint_raw: bad digest type %d",
347 dgst_type);
348 }
349 switch (k->type) {
350 case KEY_RSA1:
351 nlen = BN_num_bytes(k->rsa->n);
352 elen = BN_num_bytes(k->rsa->e);
353 len = nlen + elen;
354 blob = xmalloc(len);
355 BN_bn2bin(k->rsa->n, blob);
356 BN_bn2bin(k->rsa->e, blob + nlen);
357 break;
358 case KEY_DSA:
359 case KEY_ECDSA:
360 case KEY_RSA:
361 key_to_blob(k, &blob, &len);
362 break;
363 case KEY_DSA_CERT_V00:
364 case KEY_RSA_CERT_V00:
365 case KEY_DSA_CERT:
366 case KEY_ECDSA_CERT:
367 case KEY_RSA_CERT:
368 /* We want a fingerprint of the _key_ not of the cert */
369 otype = k->type;
370 k->type = key_type_plain(k->type);
371 key_to_blob(k, &blob, &len);
372 k->type = otype;
373 break;
374 case KEY_UNSPEC:
375 return retval;
376 default:
377 fatal("key_fingerprint_raw: bad key type %d", k->type);
378 break;
379 }
380 if (blob != NULL) {
381 retval = xmalloc(EVP_MAX_MD_SIZE);
382 EVP_DigestInit(&ctx, md);
383 EVP_DigestUpdate(&ctx, blob, len);
384 EVP_DigestFinal(&ctx, retval, dgst_raw_length);
385 memset(blob, 0, len);
386 xfree(blob);
387 } else {
388 fatal("key_fingerprint_raw: blob is null");
389 }
390 return retval;
391 }
392
393 static char *
394 key_fingerprint_hex(u_char *dgst_raw, u_int dgst_raw_len)
395 {
396 char *retval;
397 u_int i;
398
399 retval = xcalloc(1, dgst_raw_len * 3 + 1);
400 for (i = 0; i < dgst_raw_len; i++) {
401 char hex[4];
402 snprintf(hex, sizeof(hex), "%02x:", dgst_raw[i]);
403 strlcat(retval, hex, dgst_raw_len * 3 + 1);
404 }
405
406 /* Remove the trailing ':' character */
407 retval[(dgst_raw_len * 3) - 1] = '\0';
408 return retval;
409 }
410
411 static char *
412 key_fingerprint_bubblebabble(u_char *dgst_raw, u_int dgst_raw_len)
413 {
414 char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
415 char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
416 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
417 u_int i, j = 0, rounds, seed = 1;
418 char *retval;
419
420 rounds = (dgst_raw_len / 2) + 1;
421 retval = xcalloc((rounds * 6), sizeof(char));
422 retval[j++] = 'x';
423 for (i = 0; i < rounds; i++) {
424 u_int idx0, idx1, idx2, idx3, idx4;
425 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) {
426 idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) +
427 seed) % 6;
428 idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15;
429 idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) +
430 (seed / 6)) % 6;
431 retval[j++] = vowels[idx0];
432 retval[j++] = consonants[idx1];
433 retval[j++] = vowels[idx2];
434 if ((i + 1) < rounds) {
435 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15;
436 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15;
437 retval[j++] = consonants[idx3];
438 retval[j++] = '-';
439 retval[j++] = consonants[idx4];
440 seed = ((seed * 5) +
441 ((((u_int)(dgst_raw[2 * i])) * 7) +
442 ((u_int)(dgst_raw[(2 * i) + 1])))) % 36;
443 }
444 } else {
445 idx0 = seed % 6;
446 idx1 = 16;
447 idx2 = seed / 6;
448 retval[j++] = vowels[idx0];
449 retval[j++] = consonants[idx1];
450 retval[j++] = vowels[idx2];
451 }
452 }
453 retval[j++] = 'x';
454 retval[j++] = '\0';
455 return retval;
456 }
457
458 /*
459 * Draw an ASCII-Art representing the fingerprint so human brain can
460 * profit from its built-in pattern recognition ability.
461 * This technique is called "random art" and can be found in some
462 * scientific publications like this original paper:
463 *
464 * "Hash Visualization: a New Technique to improve Real-World Security",
465 * Perrig A. and Song D., 1999, International Workshop on Cryptographic
466 * Techniques and E-Commerce (CrypTEC '99)
467 * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
468 *
469 * The subject came up in a talk by Dan Kaminsky, too.
470 *
471 * If you see the picture is different, the key is different.
472 * If the picture looks the same, you still know nothing.
473 *
474 * The algorithm used here is a worm crawling over a discrete plane,
475 * leaving a trace (augmenting the field) everywhere it goes.
476 * Movement is taken from dgst_raw 2bit-wise. Bumping into walls
477 * makes the respective movement vector be ignored for this turn.
478 * Graphs are not unambiguous, because circles in graphs can be
479 * walked in either direction.
480 */
481
482 /*
483 * Field sizes for the random art. Have to be odd, so the starting point
484 * can be in the exact middle of the picture, and FLDBASE should be >=8 .
485 * Else pictures would be too dense, and drawing the frame would
486 * fail, too, because the key type would not fit in anymore.
487 */
488 #define FLDBASE 8
489 #define FLDSIZE_Y (FLDBASE + 1)
490 #define FLDSIZE_X (FLDBASE * 2 + 1)
491 static char *
492 key_fingerprint_randomart(u_char *dgst_raw, u_int dgst_raw_len, const Key *k)
493 {
494 /*
495 * Chars to be used after each other every time the worm
496 * intersects with itself. Matter of taste.
497 */
498 char *augmentation_string = " .o+=*BOX@%&#/^SE";
499 char *retval, *p;
500 u_char field[FLDSIZE_X][FLDSIZE_Y];
501 u_int i, b;
502 int x, y;
503 size_t len = strlen(augmentation_string) - 1;
504
505 retval = xcalloc(1, (FLDSIZE_X + 3) * (FLDSIZE_Y + 2));
506
507 /* initialize field */
508 memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char));
509 x = FLDSIZE_X / 2;
510 y = FLDSIZE_Y / 2;
511
512 /* process raw key */
513 for (i = 0; i < dgst_raw_len; i++) {
514 int input;
515 /* each byte conveys four 2-bit move commands */
516 input = dgst_raw[i];
517 for (b = 0; b < 4; b++) {
518 /* evaluate 2 bit, rest is shifted later */
519 x += (input & 0x1) ? 1 : -1;
520 y += (input & 0x2) ? 1 : -1;
521
522 /* assure we are still in bounds */
523 x = MAX(x, 0);
524 y = MAX(y, 0);
525 x = MIN(x, FLDSIZE_X - 1);
526 y = MIN(y, FLDSIZE_Y - 1);
527
528 /* augment the field */
529 if (field[x][y] < len - 2)
530 field[x][y]++;
531 input = input >> 2;
532 }
533 }
534
535 /* mark starting point and end point*/
536 field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1;
537 field[x][y] = len;
538
539 /* fill in retval */
540 snprintf(retval, FLDSIZE_X, "+--[%4s %4u]", key_type(k), key_size(k));
541 p = strchr(retval, '\0');
542
543 /* output upper border */
544 for (i = p - retval - 1; i < FLDSIZE_X; i++)
545 *p++ = '-';
546 *p++ = '+';
547 *p++ = '\n';
548
549 /* output content */
550 for (y = 0; y < FLDSIZE_Y; y++) {
551 *p++ = '|';
552 for (x = 0; x < FLDSIZE_X; x++)
553 *p++ = augmentation_string[MIN(field[x][y], len)];
554 *p++ = '|';
555 *p++ = '\n';
556 }
557
558 /* output lower border */
559 *p++ = '+';
560 for (i = 0; i < FLDSIZE_X; i++)
561 *p++ = '-';
562 *p++ = '+';
563
564 return retval;
565 }
566
567 char *
568 key_fingerprint(Key *k, enum fp_type dgst_type, enum fp_rep dgst_rep)
569 {
570 char *retval = NULL;
571 u_char *dgst_raw;
572 u_int dgst_raw_len;
573
574 dgst_raw = key_fingerprint_raw(k, dgst_type, &dgst_raw_len);
575 if (!dgst_raw)
576 fatal("key_fingerprint: null from key_fingerprint_raw()");
577 switch (dgst_rep) {
578 case SSH_FP_HEX:
579 retval = key_fingerprint_hex(dgst_raw, dgst_raw_len);
580 break;
581 case SSH_FP_BUBBLEBABBLE:
582 retval = key_fingerprint_bubblebabble(dgst_raw, dgst_raw_len);
583 break;
584 case SSH_FP_RANDOMART:
585 retval = key_fingerprint_randomart(dgst_raw, dgst_raw_len, k);
586 break;
587 default:
588 fatal("key_fingerprint: bad digest representation %d",
589 dgst_rep);
590 break;
591 }
592 memset(dgst_raw, 0, dgst_raw_len);
593 xfree(dgst_raw);
594 return retval;
595 }
596
597 /*
598 * Reads a multiple-precision integer in decimal from the buffer, and advances
599 * the pointer. The integer must already be initialized. This function is
600 * permitted to modify the buffer. This leaves *cpp to point just beyond the
601 * last processed (and maybe modified) character. Note that this may modify
602 * the buffer containing the number.
603 */
604 static int
605 read_bignum(char **cpp, BIGNUM * value)
606 {
607 char *cp = *cpp;
608 int old;
609
610 /* Skip any leading whitespace. */
611 for (; *cp == ' ' || *cp == '\t'; cp++)
612 ;
613
614 /* Check that it begins with a decimal digit. */
615 if (*cp < '0' || *cp > '9')
616 return 0;
617
618 /* Save starting position. */
619 *cpp = cp;
620
621 /* Move forward until all decimal digits skipped. */
622 for (; *cp >= '0' && *cp <= '9'; cp++)
623 ;
624
625 /* Save the old terminating character, and replace it by \0. */
626 old = *cp;
627 *cp = 0;
628
629 /* Parse the number. */
630 if (BN_dec2bn(&value, *cpp) == 0)
631 return 0;
632
633 /* Restore old terminating character. */
634 *cp = old;
635
636 /* Move beyond the number and return success. */
637 *cpp = cp;
638 return 1;
639 }
640
641 static int
642 write_bignum(FILE *f, BIGNUM *num)
643 {
644 char *buf = BN_bn2dec(num);
645 if (buf == NULL) {
646 error("write_bignum: BN_bn2dec() failed");
647 return 0;
648 }
649 fprintf(f, " %s", buf);
650 OPENSSL_free(buf);
651 return 1;
652 }
653
654 /* returns 1 ok, -1 error */
655 int
656 key_read(Key *ret, char **cpp)
657 {
658 Key *k;
659 int success = -1;
660 char *cp, *space;
661 int len, n, type;
662 u_int bits;
663 u_char *blob;
664 #ifdef OPENSSL_HAS_ECC
665 int curve_nid = -1;
666 #endif
667
668 cp = *cpp;
669
670 switch (ret->type) {
671 case KEY_RSA1:
672 /* Get number of bits. */
673 if (*cp < '0' || *cp > '9')
674 return -1; /* Bad bit count... */
675 for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
676 bits = 10 * bits + *cp - '0';
677 if (bits == 0)
678 return -1;
679 *cpp = cp;
680 /* Get public exponent, public modulus. */
681 if (!read_bignum(cpp, ret->rsa->e))
682 return -1;
683 if (!read_bignum(cpp, ret->rsa->n))
684 return -1;
685 /* validate the claimed number of bits */
686 if ((u_int)BN_num_bits(ret->rsa->n) != bits) {
687 verbose("key_read: claimed key size %d does not match "
688 "actual %d", bits, BN_num_bits(ret->rsa->n));
689 return -1;
690 }
691 success = 1;
692 break;
693 case KEY_UNSPEC:
694 case KEY_RSA:
695 case KEY_DSA:
696 case KEY_ECDSA:
697 case KEY_DSA_CERT_V00:
698 case KEY_RSA_CERT_V00:
699 case KEY_DSA_CERT:
700 case KEY_ECDSA_CERT:
701 case KEY_RSA_CERT:
702 space = strchr(cp, ' ');
703 if (space == NULL) {
704 debug3("key_read: missing whitespace");
705 return -1;
706 }
707 *space = '\0';
708 type = key_type_from_name(cp);
709 #ifdef OPENSSL_HAS_ECC
710 if (key_type_plain(type) == KEY_ECDSA &&
711 (curve_nid = key_ecdsa_nid_from_name(cp)) == -1) {
712 debug("key_read: invalid curve");
713 return -1;
714 }
715 #endif
716 *space = ' ';
717 if (type == KEY_UNSPEC) {
718 debug3("key_read: missing keytype");
719 return -1;
720 }
721 cp = space+1;
722 if (*cp == '\0') {
723 debug3("key_read: short string");
724 return -1;
725 }
726 if (ret->type == KEY_UNSPEC) {
727 ret->type = type;
728 } else if (ret->type != type) {
729 /* is a key, but different type */
730 debug3("key_read: type mismatch");
731 return -1;
732 }
733 len = 2*strlen(cp);
734 blob = xmalloc(len);
735 n = uudecode(cp, blob, len);
736 if (n < 0) {
737 error("key_read: uudecode %s failed", cp);
738 xfree(blob);
739 return -1;
740 }
741 k = key_from_blob(blob, (u_int)n);
742 xfree(blob);
743 if (k == NULL) {
744 error("key_read: key_from_blob %s failed", cp);
745 return -1;
746 }
747 if (k->type != type) {
748 error("key_read: type mismatch: encoding error");
749 key_free(k);
750 return -1;
751 }
752 #ifdef OPENSSL_HAS_ECC
753 if (key_type_plain(type) == KEY_ECDSA &&
754 curve_nid != k->ecdsa_nid) {
755 error("key_read: type mismatch: EC curve mismatch");
756 key_free(k);
757 return -1;
758 }
759 #endif
760 /*XXXX*/
761 if (key_is_cert(ret)) {
762 if (!key_is_cert(k)) {
763 error("key_read: loaded key is not a cert");
764 key_free(k);
765 return -1;
766 }
767 if (ret->cert != NULL)
768 cert_free(ret->cert);
769 ret->cert = k->cert;
770 k->cert = NULL;
771 }
772 if (key_type_plain(ret->type) == KEY_RSA) {
773 if (ret->rsa != NULL)
774 RSA_free(ret->rsa);
775 ret->rsa = k->rsa;
776 k->rsa = NULL;
777 #ifdef DEBUG_PK
778 RSA_print_fp(stderr, ret->rsa, 8);
779 #endif
780 }
781 if (key_type_plain(ret->type) == KEY_DSA) {
782 if (ret->dsa != NULL)
783 DSA_free(ret->dsa);
784 ret->dsa = k->dsa;
785 k->dsa = NULL;
786 #ifdef DEBUG_PK
787 DSA_print_fp(stderr, ret->dsa, 8);
788 #endif
789 }
790 #ifdef OPENSSL_HAS_ECC
791 if (key_type_plain(ret->type) == KEY_ECDSA) {
792 if (ret->ecdsa != NULL)
793 EC_KEY_free(ret->ecdsa);
794 ret->ecdsa = k->ecdsa;
795 ret->ecdsa_nid = k->ecdsa_nid;
796 k->ecdsa = NULL;
797 k->ecdsa_nid = -1;
798 #ifdef DEBUG_PK
799 key_dump_ec_key(ret->ecdsa);
800 #endif
801 }
802 #endif
803 success = 1;
804 /*XXXX*/
805 key_free(k);
806 if (success != 1)
807 break;
808 /* advance cp: skip whitespace and data */
809 while (*cp == ' ' || *cp == '\t')
810 cp++;
811 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
812 cp++;
813 *cpp = cp;
814 break;
815 default:
816 fatal("key_read: bad key type: %d", ret->type);
817 break;
818 }
819 return success;
820 }
821
822 int
823 key_write(const Key *key, FILE *f)
824 {
825 int n, success = 0;
826 u_int len, bits = 0;
827 u_char *blob;
828 char *uu;
829
830 if (key_is_cert(key)) {
831 if (key->cert == NULL) {
832 error("%s: no cert data", __func__);
833 return 0;
834 }
835 if (buffer_len(&key->cert->certblob) == 0) {
836 error("%s: no signed certificate blob", __func__);
837 return 0;
838 }
839 }
840
841 switch (key->type) {
842 case KEY_RSA1:
843 if (key->rsa == NULL)
844 return 0;
845 /* size of modulus 'n' */
846 bits = BN_num_bits(key->rsa->n);
847 fprintf(f, "%u", bits);
848 if (write_bignum(f, key->rsa->e) &&
849 write_bignum(f, key->rsa->n))
850 return 1;
851 error("key_write: failed for RSA key");
852 return 0;
853 case KEY_DSA:
854 case KEY_DSA_CERT_V00:
855 case KEY_DSA_CERT:
856 if (key->dsa == NULL)
857 return 0;
858 break;
859 #ifdef OPENSSL_HAS_ECC
860 case KEY_ECDSA:
861 case KEY_ECDSA_CERT:
862 if (key->ecdsa == NULL)
863 return 0;
864 break;
865 #endif
866 case KEY_RSA:
867 case KEY_RSA_CERT_V00:
868 case KEY_RSA_CERT:
869 if (key->rsa == NULL)
870 return 0;
871 break;
872 default:
873 return 0;
874 }
875
876 key_to_blob(key, &blob, &len);
877 uu = xmalloc(2*len);
878 n = uuencode(blob, len, uu, 2*len);
879 if (n > 0) {
880 fprintf(f, "%s %s", key_ssh_name(key), uu);
881 success = 1;
882 }
883 xfree(blob);
884 xfree(uu);
885
886 return success;
887 }
888
889 const char *
890 key_type(const Key *k)
891 {
892 switch (k->type) {
893 case KEY_RSA1:
894 return "RSA1";
895 case KEY_RSA:
896 return "RSA";
897 case KEY_DSA:
898 return "DSA";
899 #ifdef OPENSSL_HAS_ECC
900 case KEY_ECDSA:
901 return "ECDSA";
902 #endif
903 case KEY_RSA_CERT_V00:
904 return "RSA-CERT-V00";
905 case KEY_DSA_CERT_V00:
906 return "DSA-CERT-V00";
907 case KEY_RSA_CERT:
908 return "RSA-CERT";
909 case KEY_DSA_CERT:
910 return "DSA-CERT";
911 #ifdef OPENSSL_HAS_ECC
912 case KEY_ECDSA_CERT:
913 return "ECDSA-CERT";
914 #endif
915 }
916 return "unknown";
917 }
918
919 const char *
920 key_cert_type(const Key *k)
921 {
922 switch (k->cert->type) {
923 case SSH2_CERT_TYPE_USER:
924 return "user";
925 case SSH2_CERT_TYPE_HOST:
926 return "host";
927 default:
928 return "unknown";
929 }
930 }
931
932 static const char *
933 key_ssh_name_from_type_nid(int type, int nid)
934 {
935 switch (type) {
936 case KEY_RSA:
937 return "ssh-rsa";
938 case KEY_DSA:
939 return "ssh-dss";
940 case KEY_RSA_CERT_V00:
941 return "ssh-rsa-cert-v00@openssh.com";
942 case KEY_DSA_CERT_V00:
943 return "ssh-dss-cert-v00@openssh.com";
944 case KEY_RSA_CERT:
945 return "ssh-rsa-cert-v01@openssh.com";
946 case KEY_DSA_CERT:
947 return "ssh-dss-cert-v01@openssh.com";
948 #ifdef OPENSSL_HAS_ECC
949 case KEY_ECDSA:
950 switch (nid) {
951 case NID_X9_62_prime256v1:
952 return "ecdsa-sha2-nistp256";
953 case NID_secp384r1:
954 return "ecdsa-sha2-nistp384";
955 case NID_secp521r1:
956 return "ecdsa-sha2-nistp521";
957 default:
958 break;
959 }
960 break;
961 case KEY_ECDSA_CERT:
962 switch (nid) {
963 case NID_X9_62_prime256v1:
964 return "ecdsa-sha2-nistp256-cert-v01@openssh.com";
965 case NID_secp384r1:
966 return "ecdsa-sha2-nistp384-cert-v01@openssh.com";
967 case NID_secp521r1:
968 return "ecdsa-sha2-nistp521-cert-v01@openssh.com";
969 default:
970 break;
971 }
972 break;
973 #endif /* OPENSSL_HAS_ECC */
974 }
975 return "ssh-unknown";
976 }
977
978 const char *
979 key_ssh_name(const Key *k)
980 {
981 return key_ssh_name_from_type_nid(k->type, k->ecdsa_nid);
982 }
983
984 const char *
985 key_ssh_name_plain(const Key *k)
986 {
987 return key_ssh_name_from_type_nid(key_type_plain(k->type),
988 k->ecdsa_nid);
989 }
990
991 u_int
992 key_size(const Key *k)
993 {
994 switch (k->type) {
995 case KEY_RSA1:
996 case KEY_RSA:
997 case KEY_RSA_CERT_V00:
998 case KEY_RSA_CERT:
999 return BN_num_bits(k->rsa->n);
1000 case KEY_DSA:
1001 case KEY_DSA_CERT_V00:
1002 case KEY_DSA_CERT:
1003 return BN_num_bits(k->dsa->p);
1004 #ifdef OPENSSL_HAS_ECC
1005 case KEY_ECDSA:
1006 case KEY_ECDSA_CERT:
1007 return key_curve_nid_to_bits(k->ecdsa_nid);
1008 #endif
1009 }
1010 return 0;
1011 }
1012
1013 static RSA *
1014 rsa_generate_private_key(u_int bits)
1015 {
1016 RSA *private;
1017
1018 private = RSA_generate_key(bits, RSA_F4, NULL, NULL);
1019 if (private == NULL)
1020 fatal("rsa_generate_private_key: key generation failed.");
1021 return private;
1022 }
1023
1024 static DSA*
1025 dsa_generate_private_key(u_int bits)
1026 {
1027 DSA *private = DSA_generate_parameters(bits, NULL, 0, NULL, NULL, NULL, NULL);
1028
1029 if (private == NULL)
1030 fatal("dsa_generate_private_key: DSA_generate_parameters failed");
1031 if (!DSA_generate_key(private))
1032 fatal("dsa_generate_private_key: DSA_generate_key failed.");
1033 if (private == NULL)
1034 fatal("dsa_generate_private_key: NULL.");
1035 return private;
1036 }
1037
1038 int
1039 key_ecdsa_bits_to_nid(int bits)
1040 {
1041 switch (bits) {
1042 #ifdef OPENSSL_HAS_ECC
1043 case 256:
1044 return NID_X9_62_prime256v1;
1045 case 384:
1046 return NID_secp384r1;
1047 case 521:
1048 return NID_secp521r1;
1049 #endif
1050 default:
1051 return -1;
1052 }
1053 }
1054
1055 #ifdef OPENSSL_HAS_ECC
1056 /*
1057 * This is horrid, but OpenSSL's PEM_read_PrivateKey seems not to restore
1058 * the EC_GROUP nid when loading a key...
1059 */
1060 int
1061 key_ecdsa_group_to_nid(const EC_GROUP *g)
1062 {
1063 EC_GROUP *eg;
1064 int nids[] = {
1065 NID_X9_62_prime256v1,
1066 NID_secp384r1,
1067 NID_secp521r1,
1068 -1
1069 };
1070 u_int i;
1071 BN_CTX *bnctx;
1072
1073 if ((bnctx = BN_CTX_new()) == NULL)
1074 fatal("%s: BN_CTX_new() failed", __func__);
1075 for (i = 0; nids[i] != -1; i++) {
1076 if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL)
1077 fatal("%s: EC_GROUP_new_by_curve_name failed",
1078 __func__);
1079 if (EC_GROUP_cmp(g, eg, bnctx) == 0) {
1080 EC_GROUP_free(eg);
1081 break;
1082 }
1083 EC_GROUP_free(eg);
1084 }
1085 BN_CTX_free(bnctx);
1086 debug3("%s: nid = %d", __func__, nids[i]);
1087 return nids[i];
1088 }
1089
1090 static EC_KEY*
1091 ecdsa_generate_private_key(u_int bits, int *nid)
1092 {
1093 EC_KEY *private;
1094
1095 if ((*nid = key_ecdsa_bits_to_nid(bits)) == -1)
1096 fatal("%s: invalid key length", __func__);
1097 if ((private = EC_KEY_new_by_curve_name(*nid)) == NULL)
1098 fatal("%s: EC_KEY_new_by_curve_name failed", __func__);
1099 if (EC_KEY_generate_key(private) != 1)
1100 fatal("%s: EC_KEY_generate_key failed", __func__);
1101 return private;
1102 }
1103 #endif /* OPENSSL_HAS_ECC */
1104
1105 Key *
1106 key_generate(int type, u_int bits)
1107 {
1108 Key *k = key_new(KEY_UNSPEC);
1109 switch (type) {
1110 case KEY_DSA:
1111 k->dsa = dsa_generate_private_key(bits);
1112 break;
1113 #ifdef OPENSSL_HAS_ECC
1114 case KEY_ECDSA:
1115 k->ecdsa = ecdsa_generate_private_key(bits, &k->ecdsa_nid);
1116 break;
1117 #endif
1118 case KEY_RSA:
1119 case KEY_RSA1:
1120 k->rsa = rsa_generate_private_key(bits);
1121 break;
1122 case KEY_RSA_CERT_V00:
1123 case KEY_DSA_CERT_V00:
1124 case KEY_RSA_CERT:
1125 case KEY_DSA_CERT:
1126 fatal("key_generate: cert keys cannot be generated directly");
1127 default:
1128 fatal("key_generate: unknown type %d", type);
1129 }
1130 k->type = type;
1131 return k;
1132 }
1133
1134 void
1135 key_cert_copy(const Key *from_key, struct Key *to_key)
1136 {
1137 u_int i;
1138 const struct KeyCert *from;
1139 struct KeyCert *to;
1140
1141 if (to_key->cert != NULL) {
1142 cert_free(to_key->cert);
1143 to_key->cert = NULL;
1144 }
1145
1146 if ((from = from_key->cert) == NULL)
1147 return;
1148
1149 to = to_key->cert = cert_new();
1150
1151 buffer_append(&to->certblob, buffer_ptr(&from->certblob),
1152 buffer_len(&from->certblob));
1153
1154 buffer_append(&to->critical,
1155 buffer_ptr(&from->critical), buffer_len(&from->critical));
1156 buffer_append(&to->extensions,
1157 buffer_ptr(&from->extensions), buffer_len(&from->extensions));
1158
1159 to->serial = from->serial;
1160 to->type = from->type;
1161 to->key_id = from->key_id == NULL ? NULL : xstrdup(from->key_id);
1162 to->valid_after = from->valid_after;
1163 to->valid_before = from->valid_before;
1164 to->signature_key = from->signature_key == NULL ?
1165 NULL : key_from_private(from->signature_key);
1166
1167 to->nprincipals = from->nprincipals;
1168 if (to->nprincipals > CERT_MAX_PRINCIPALS)
1169 fatal("%s: nprincipals (%u) > CERT_MAX_PRINCIPALS (%u)",
1170 __func__, to->nprincipals, CERT_MAX_PRINCIPALS);
1171 if (to->nprincipals > 0) {
1172 to->principals = xcalloc(from->nprincipals,
1173 sizeof(*to->principals));
1174 for (i = 0; i < to->nprincipals; i++)
1175 to->principals[i] = xstrdup(from->principals[i]);
1176 }
1177 }
1178
1179 Key *
1180 key_from_private(const Key *k)
1181 {
1182 Key *n = NULL;
1183 switch (k->type) {
1184 case KEY_DSA:
1185 case KEY_DSA_CERT_V00:
1186 case KEY_DSA_CERT:
1187 n = key_new(k->type);
1188 if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) ||
1189 (BN_copy(n->dsa->q, k->dsa->q) == NULL) ||
1190 (BN_copy(n->dsa->g, k->dsa->g) == NULL) ||
1191 (BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL))
1192 fatal("key_from_private: BN_copy failed");
1193 break;
1194 #ifdef OPENSSL_HAS_ECC
1195 case KEY_ECDSA:
1196 case KEY_ECDSA_CERT:
1197 n = key_new(k->type);
1198 n->ecdsa_nid = k->ecdsa_nid;
1199 if ((n->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid)) == NULL)
1200 fatal("%s: EC_KEY_new_by_curve_name failed", __func__);
1201 if (EC_KEY_set_public_key(n->ecdsa,
1202 EC_KEY_get0_public_key(k->ecdsa)) != 1)
1203 fatal("%s: EC_KEY_set_public_key failed", __func__);
1204 break;
1205 #endif
1206 case KEY_RSA:
1207 case KEY_RSA1:
1208 case KEY_RSA_CERT_V00:
1209 case KEY_RSA_CERT:
1210 n = key_new(k->type);
1211 if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) ||
1212 (BN_copy(n->rsa->e, k->rsa->e) == NULL))
1213 fatal("key_from_private: BN_copy failed");
1214 break;
1215 default:
1216 fatal("key_from_private: unknown type %d", k->type);
1217 break;
1218 }
1219 if (key_is_cert(k))
1220 key_cert_copy(k, n);
1221 return n;
1222 }
1223
1224 int
1225 key_type_from_name(char *name)
1226 {
1227 if (strcmp(name, "rsa1") == 0) {
1228 return KEY_RSA1;
1229 } else if (strcmp(name, "rsa") == 0) {
1230 return KEY_RSA;
1231 } else if (strcmp(name, "dsa") == 0) {
1232 return KEY_DSA;
1233 } else if (strcmp(name, "ssh-rsa") == 0) {
1234 return KEY_RSA;
1235 } else if (strcmp(name, "ssh-dss") == 0) {
1236 return KEY_DSA;
1237 #ifdef OPENSSL_HAS_ECC
1238 } else if (strcmp(name, "ecdsa") == 0 ||
1239 strcmp(name, "ecdsa-sha2-nistp256") == 0 ||
1240 strcmp(name, "ecdsa-sha2-nistp384") == 0 ||
1241 strcmp(name, "ecdsa-sha2-nistp521") == 0) {
1242 return KEY_ECDSA;
1243 #endif
1244 } else if (strcmp(name, "ssh-rsa-cert-v00@openssh.com") == 0) {
1245 return KEY_RSA_CERT_V00;
1246 } else if (strcmp(name, "ssh-dss-cert-v00@openssh.com") == 0) {
1247 return KEY_DSA_CERT_V00;
1248 } else if (strcmp(name, "ssh-rsa-cert-v01@openssh.com") == 0) {
1249 return KEY_RSA_CERT;
1250 } else if (strcmp(name, "ssh-dss-cert-v01@openssh.com") == 0) {
1251 return KEY_DSA_CERT;
1252 #ifdef OPENSSL_HAS_ECC
1253 } else if (strcmp(name, "ecdsa-sha2-nistp256-cert-v01@openssh.com") == 0 ||
1254 strcmp(name, "ecdsa-sha2-nistp384-cert-v01@openssh.com") == 0 ||
1255 strcmp(name, "ecdsa-sha2-nistp521-cert-v01@openssh.com") == 0) {
1256 return KEY_ECDSA_CERT;
1257 #endif
1258 }
1259
1260 debug2("key_type_from_name: unknown key type '%s'", name);
1261 return KEY_UNSPEC;
1262 }
1263
1264 int
1265 key_ecdsa_nid_from_name(const char *name)
1266 {
1267 #ifdef OPENSSL_HAS_ECC
1268 if (strcmp(name, "ecdsa-sha2-nistp256") == 0 ||
1269 strcmp(name, "ecdsa-sha2-nistp256-cert-v01@openssh.com") == 0)
1270 return NID_X9_62_prime256v1;
1271 if (strcmp(name, "ecdsa-sha2-nistp384") == 0 ||
1272 strcmp(name, "ecdsa-sha2-nistp384-cert-v01@openssh.com") == 0)
1273 return NID_secp384r1;
1274 if (strcmp(name, "ecdsa-sha2-nistp521") == 0 ||
1275 strcmp(name, "ecdsa-sha2-nistp521-cert-v01@openssh.com") == 0)
1276 return NID_secp521r1;
1277 #endif /* OPENSSL_HAS_ECC */
1278
1279 debug2("%s: unknown/non-ECDSA key type '%s'", __func__, name);
1280 return -1;
1281 }
1282
1283 int
1284 key_names_valid2(const char *names)
1285 {
1286 char *s, *cp, *p;
1287
1288 if (names == NULL || strcmp(names, "") == 0)
1289 return 0;
1290 s = cp = xstrdup(names);
1291 for ((p = strsep(&cp, ",")); p && *p != '\0';
1292 (p = strsep(&cp, ","))) {
1293 switch (key_type_from_name(p)) {
1294 case KEY_RSA1:
1295 case KEY_UNSPEC:
1296 xfree(s);
1297 return 0;
1298 }
1299 }
1300 debug3("key names ok: [%s]", names);
1301 xfree(s);
1302 return 1;
1303 }
1304
1305 static int
1306 cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
1307 {
1308 u_char *principals, *critical, *exts, *sig_key, *sig;
1309 u_int signed_len, plen, clen, sklen, slen, kidlen, elen;
1310 Buffer tmp;
1311 char *principal;
1312 int ret = -1;
1313 int v00 = key->type == KEY_DSA_CERT_V00 ||
1314 key->type == KEY_RSA_CERT_V00;
1315
1316 buffer_init(&tmp);
1317
1318 /* Copy the entire key blob for verification and later serialisation */
1319 buffer_append(&key->cert->certblob, blob, blen);
1320
1321 elen = 0; /* Not touched for v00 certs */
1322 principals = exts = critical = sig_key = sig = NULL;
1323 if ((!v00 && buffer_get_int64_ret(&key->cert->serial, b) != 0) ||
1324 buffer_get_int_ret(&key->cert->type, b) != 0 ||
1325 (key->cert->key_id = buffer_get_cstring_ret(b, &kidlen)) == NULL ||
1326 (principals = buffer_get_string_ret(b, &plen)) == NULL ||
1327 buffer_get_int64_ret(&key->cert->valid_after, b) != 0 ||
1328 buffer_get_int64_ret(&key->cert->valid_before, b) != 0 ||
1329 (critical = buffer_get_string_ret(b, &clen)) == NULL ||
1330 (!v00 && (exts = buffer_get_string_ret(b, &elen)) == NULL) ||
1331 (v00 && buffer_get_string_ptr_ret(b, NULL) == NULL) || /* nonce */
1332 buffer_get_string_ptr_ret(b, NULL) == NULL || /* reserved */
1333 (sig_key = buffer_get_string_ret(b, &sklen)) == NULL) {
1334 error("%s: parse error", __func__);
1335 goto out;
1336 }
1337
1338 if (kidlen != strlen(key->cert->key_id)) {
1339 error("%s: key ID contains \\0 character", __func__);
1340 goto out;
1341 }
1342
1343 /* Signature is left in the buffer so we can calculate this length */
1344 signed_len = buffer_len(&key->cert->certblob) - buffer_len(b);
1345
1346 if ((sig = buffer_get_string_ret(b, &slen)) == NULL) {
1347 error("%s: parse error", __func__);
1348 goto out;
1349 }
1350
1351 if (key->cert->type != SSH2_CERT_TYPE_USER &&
1352 key->cert->type != SSH2_CERT_TYPE_HOST) {
1353 error("Unknown certificate type %u", key->cert->type);
1354 goto out;
1355 }
1356
1357 buffer_append(&tmp, principals, plen);
1358 while (buffer_len(&tmp) > 0) {
1359 if (key->cert->nprincipals >= CERT_MAX_PRINCIPALS) {
1360 error("%s: Too many principals", __func__);
1361 goto out;
1362 }
1363 if ((principal = buffer_get_cstring_ret(&tmp, &plen)) == NULL) {
1364 error("%s: Principals data invalid", __func__);
1365 goto out;
1366 }
1367 key->cert->principals = xrealloc(key->cert->principals,
1368 key->cert->nprincipals + 1, sizeof(*key->cert->principals));
1369 key->cert->principals[key->cert->nprincipals++] = principal;
1370 }
1371
1372 buffer_clear(&tmp);
1373
1374 buffer_append(&key->cert->critical, critical, clen);
1375 buffer_append(&tmp, critical, clen);
1376 /* validate structure */
1377 while (buffer_len(&tmp) != 0) {
1378 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL ||
1379 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) {
1380 error("%s: critical option data invalid", __func__);
1381 goto out;
1382 }
1383 }
1384 buffer_clear(&tmp);
1385
1386 buffer_append(&key->cert->extensions, exts, elen);
1387 buffer_append(&tmp, exts, elen);
1388 /* validate structure */
1389 while (buffer_len(&tmp) != 0) {
1390 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL ||
1391 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) {
1392 error("%s: extension data invalid", __func__);
1393 goto out;
1394 }
1395 }
1396 buffer_clear(&tmp);
1397
1398 if ((key->cert->signature_key = key_from_blob(sig_key,
1399 sklen)) == NULL) {
1400 error("%s: Signature key invalid", __func__);
1401 goto out;
1402 }
1403 if (key->cert->signature_key->type != KEY_RSA &&
1404 key->cert->signature_key->type != KEY_DSA &&
1405 key->cert->signature_key->type != KEY_ECDSA) {
1406 error("%s: Invalid signature key type %s (%d)", __func__,
1407 key_type(key->cert->signature_key),
1408 key->cert->signature_key->type);
1409 goto out;
1410 }
1411
1412 switch (key_verify(key->cert->signature_key, sig, slen,
1413 buffer_ptr(&key->cert->certblob), signed_len)) {
1414 case 1:
1415 ret = 0;
1416 break; /* Good signature */
1417 case 0:
1418 error("%s: Invalid signature on certificate", __func__);
1419 goto out;
1420 case -1:
1421 error("%s: Certificate signature verification failed",
1422 __func__);
1423 goto out;
1424 }
1425
1426 out:
1427 buffer_free(&tmp);
1428 if (principals != NULL)
1429 xfree(principals);
1430 if (critical != NULL)
1431 xfree(critical);
1432 if (exts != NULL)
1433 xfree(exts);
1434 if (sig_key != NULL)
1435 xfree(sig_key);
1436 if (sig != NULL)
1437 xfree(sig);
1438 return ret;
1439 }
1440
1441 Key *
1442 key_from_blob(const u_char *blob, u_int blen)
1443 {
1444 Buffer b;
1445 int rlen, type;
1446 char *ktype = NULL, *curve = NULL;
1447 Key *key = NULL;
1448 #ifdef OPENSSL_HAS_ECC
1449 EC_POINT *q = NULL;
1450 int nid = -1;
1451 #endif
1452
1453 #ifdef DEBUG_PK
1454 dump_base64(stderr, blob, blen);
1455 #endif
1456 buffer_init(&b);
1457 buffer_append(&b, blob, blen);
1458 if ((ktype = buffer_get_cstring_ret(&b, NULL)) == NULL) {
1459 error("key_from_blob: can't read key type");
1460 goto out;
1461 }
1462
1463 type = key_type_from_name(ktype);
1464 #ifdef OPENSSL_HAS_ECC
1465 if (key_type_plain(type) == KEY_ECDSA)
1466 nid = key_ecdsa_nid_from_name(ktype);
1467 #endif
1468
1469 switch (type) {
1470 case KEY_RSA_CERT:
1471 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */
1472 /* FALLTHROUGH */
1473 case KEY_RSA:
1474 case KEY_RSA_CERT_V00:
1475 key = key_new(type);
1476 if (buffer_get_bignum2_ret(&b, key->rsa->e) == -1 ||
1477 buffer_get_bignum2_ret(&b, key->rsa->n) == -1) {
1478 error("key_from_blob: can't read rsa key");
1479 badkey:
1480 key_free(key);
1481 key = NULL;
1482 goto out;
1483 }
1484 #ifdef DEBUG_PK
1485 RSA_print_fp(stderr, key->rsa, 8);
1486 #endif
1487 break;
1488 case KEY_DSA_CERT:
1489 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */
1490 /* FALLTHROUGH */
1491 case KEY_DSA:
1492 case KEY_DSA_CERT_V00:
1493 key = key_new(type);
1494 if (buffer_get_bignum2_ret(&b, key->dsa->p) == -1 ||
1495 buffer_get_bignum2_ret(&b, key->dsa->q) == -1 ||
1496 buffer_get_bignum2_ret(&b, key->dsa->g) == -1 ||
1497 buffer_get_bignum2_ret(&b, key->dsa->pub_key) == -1) {
1498 error("key_from_blob: can't read dsa key");
1499 goto badkey;
1500 }
1501 #ifdef DEBUG_PK
1502 DSA_print_fp(stderr, key->dsa, 8);
1503 #endif
1504 break;
1505 #ifdef OPENSSL_HAS_ECC
1506 case KEY_ECDSA_CERT:
1507 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */
1508 /* FALLTHROUGH */
1509 case KEY_ECDSA:
1510 key = key_new(type);
1511 key->ecdsa_nid = nid;
1512 if ((curve = buffer_get_string_ret(&b, NULL)) == NULL) {
1513 error("key_from_blob: can't read ecdsa curve");
1514 goto badkey;
1515 }
1516 if (key->ecdsa_nid != key_curve_name_to_nid(curve)) {
1517 error("key_from_blob: ecdsa curve doesn't match type");
1518 goto badkey;
1519 }
1520 if (key->ecdsa != NULL)
1521 EC_KEY_free(key->ecdsa);
1522 if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid))
1523 == NULL)
1524 fatal("key_from_blob: EC_KEY_new_by_curve_name failed");
1525 if ((q = EC_POINT_new(EC_KEY_get0_group(key->ecdsa))) == NULL)
1526 fatal("key_from_blob: EC_POINT_new failed");
1527 if (buffer_get_ecpoint_ret(&b, EC_KEY_get0_group(key->ecdsa),
1528 q) == -1) {
1529 error("key_from_blob: can't read ecdsa key point");
1530 goto badkey;
1531 }
1532 if (key_ec_validate_public(EC_KEY_get0_group(key->ecdsa),
1533 q) != 0)
1534 goto badkey;
1535 if (EC_KEY_set_public_key(key->ecdsa, q) != 1)
1536 fatal("key_from_blob: EC_KEY_set_public_key failed");
1537 #ifdef DEBUG_PK
1538 key_dump_ec_point(EC_KEY_get0_group(key->ecdsa), q);
1539 #endif
1540 break;
1541 #endif /* OPENSSL_HAS_ECC */
1542 case KEY_UNSPEC:
1543 key = key_new(type);
1544 break;
1545 default:
1546 error("key_from_blob: cannot handle type %s", ktype);
1547 goto out;
1548 }
1549 if (key_is_cert(key) && cert_parse(&b, key, blob, blen) == -1) {
1550 error("key_from_blob: can't parse cert data");
1551 goto badkey;
1552 }
1553 rlen = buffer_len(&b);
1554 if (key != NULL && rlen != 0)
1555 error("key_from_blob: remaining bytes in key blob %d", rlen);
1556 out:
1557 if (ktype != NULL)
1558 xfree(ktype);
1559 if (curve != NULL)
1560 xfree(curve);
1561 #ifdef OPENSSL_HAS_ECC
1562 if (q != NULL)
1563 EC_POINT_free(q);
1564 #endif
1565 buffer_free(&b);
1566 return key;
1567 }
1568
1569 int
1570 key_to_blob(const Key *key, u_char **blobp, u_int *lenp)
1571 {
1572 Buffer b;
1573 int len;
1574
1575 if (key == NULL) {
1576 error("key_to_blob: key == NULL");
1577 return 0;
1578 }
1579 buffer_init(&b);
1580 switch (key->type) {
1581 case KEY_DSA_CERT_V00:
1582 case KEY_RSA_CERT_V00:
1583 case KEY_DSA_CERT:
1584 case KEY_ECDSA_CERT:
1585 case KEY_RSA_CERT:
1586 /* Use the existing blob */
1587 buffer_append(&b, buffer_ptr(&key->cert->certblob),
1588 buffer_len(&key->cert->certblob));
1589 break;
1590 case KEY_DSA:
1591 buffer_put_cstring(&b, key_ssh_name(key));
1592 buffer_put_bignum2(&b, key->dsa->p);
1593 buffer_put_bignum2(&b, key->dsa->q);
1594 buffer_put_bignum2(&b, key->dsa->g);
1595 buffer_put_bignum2(&b, key->dsa->pub_key);
1596 break;
1597 #ifdef OPENSSL_HAS_ECC
1598 case KEY_ECDSA:
1599 buffer_put_cstring(&b, key_ssh_name(key));
1600 buffer_put_cstring(&b, key_curve_nid_to_name(key->ecdsa_nid));
1601 buffer_put_ecpoint(&b, EC_KEY_get0_group(key->ecdsa),
1602 EC_KEY_get0_public_key(key->ecdsa));
1603 break;
1604 #endif
1605 case KEY_RSA:
1606 buffer_put_cstring(&b, key_ssh_name(key));
1607 buffer_put_bignum2(&b, key->rsa->e);
1608 buffer_put_bignum2(&b, key->rsa->n);
1609 break;
1610 default:
1611 error("key_to_blob: unsupported key type %d", key->type);
1612 buffer_free(&b);
1613 return 0;
1614 }
1615 len = buffer_len(&b);
1616 if (lenp != NULL)
1617 *lenp = len;
1618 if (blobp != NULL) {
1619 *blobp = xmalloc(len);
1620 memcpy(*blobp, buffer_ptr(&b), len);
1621 }
1622 memset(buffer_ptr(&b), 0, len);
1623 buffer_free(&b);
1624 return len;
1625 }
1626
1627 int
1628 key_sign(
1629 const Key *key,
1630 u_char **sigp, u_int *lenp,
1631 const u_char *data, u_int datalen)
1632 {
1633 switch (key->type) {
1634 case KEY_DSA_CERT_V00:
1635 case KEY_DSA_CERT:
1636 case KEY_DSA:
1637 return ssh_dss_sign(key, sigp, lenp, data, datalen);
1638 #ifdef OPENSSL_HAS_ECC
1639 case KEY_ECDSA_CERT:
1640 case KEY_ECDSA:
1641 return ssh_ecdsa_sign(key, sigp, lenp, data, datalen);
1642 #endif
1643 case KEY_RSA_CERT_V00:
1644 case KEY_RSA_CERT:
1645 case KEY_RSA:
1646 return ssh_rsa_sign(key, sigp, lenp, data, datalen);
1647 default:
1648 error("key_sign: invalid key type %d", key->type);
1649 return -1;
1650 }
1651 }
1652
1653 /*
1654 * key_verify returns 1 for a correct signature, 0 for an incorrect signature
1655 * and -1 on error.
1656 */
1657 int
1658 key_verify(
1659 const Key *key,
1660 const u_char *signature, u_int signaturelen,
1661 const u_char *data, u_int datalen)
1662 {
1663 if (signaturelen == 0)
1664 return -1;
1665
1666 switch (key->type) {
1667 case KEY_DSA_CERT_V00:
1668 case KEY_DSA_CERT:
1669 case KEY_DSA:
1670 return ssh_dss_verify(key, signature, signaturelen, data, datalen);
1671 #ifdef OPENSSL_HAS_ECC
1672 case KEY_ECDSA_CERT:
1673 case KEY_ECDSA:
1674 return ssh_ecdsa_verify(key, signature, signaturelen, data, datalen);
1675 #endif
1676 case KEY_RSA_CERT_V00:
1677 case KEY_RSA_CERT:
1678 case KEY_RSA:
1679 return ssh_rsa_verify(key, signature, signaturelen, data, datalen);
1680 default:
1681 error("key_verify: invalid key type %d", key->type);
1682 return -1;
1683 }
1684 }
1685
1686 /* Converts a private to a public key */
1687 Key *
1688 key_demote(const Key *k)
1689 {
1690 Key *pk;
1691
1692 pk = xcalloc(1, sizeof(*pk));
1693 pk->type = k->type;
1694 pk->flags = k->flags;
1695 pk->ecdsa_nid = k->ecdsa_nid;
1696 pk->dsa = NULL;
1697 pk->ecdsa = NULL;
1698 pk->rsa = NULL;
1699
1700 switch (k->type) {
1701 case KEY_RSA_CERT_V00:
1702 case KEY_RSA_CERT:
1703 key_cert_copy(k, pk);
1704 /* FALLTHROUGH */
1705 case KEY_RSA1:
1706 case KEY_RSA:
1707 if ((pk->rsa = RSA_new()) == NULL)
1708 fatal("key_demote: RSA_new failed");
1709 if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL)
1710 fatal("key_demote: BN_dup failed");
1711 if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL)
1712 fatal("key_demote: BN_dup failed");
1713 break;
1714 case KEY_DSA_CERT_V00:
1715 case KEY_DSA_CERT:
1716 key_cert_copy(k, pk);
1717 /* FALLTHROUGH */
1718 case KEY_DSA:
1719 if ((pk->dsa = DSA_new()) == NULL)
1720 fatal("key_demote: DSA_new failed");
1721 if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL)
1722 fatal("key_demote: BN_dup failed");
1723 if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL)
1724 fatal("key_demote: BN_dup failed");
1725 if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL)
1726 fatal("key_demote: BN_dup failed");
1727 if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL)
1728 fatal("key_demote: BN_dup failed");
1729 break;
1730 #ifdef OPENSSL_HAS_ECC
1731 case KEY_ECDSA_CERT:
1732 key_cert_copy(k, pk);
1733 /* FALLTHROUGH */
1734 case KEY_ECDSA:
1735 if ((pk->ecdsa = EC_KEY_new_by_curve_name(pk->ecdsa_nid)) == NULL)
1736 fatal("key_demote: EC_KEY_new_by_curve_name failed");
1737 if (EC_KEY_set_public_key(pk->ecdsa,
1738 EC_KEY_get0_public_key(k->ecdsa)) != 1)
1739 fatal("key_demote: EC_KEY_set_public_key failed");
1740 break;
1741 #endif
1742 default:
1743 fatal("key_free: bad key type %d", k->type);
1744 break;
1745 }
1746
1747 return (pk);
1748 }
1749
1750 int
1751 key_is_cert(const Key *k)
1752 {
1753 if (k == NULL)
1754 return 0;
1755 switch (k->type) {
1756 case KEY_RSA_CERT_V00:
1757 case KEY_DSA_CERT_V00:
1758 case KEY_RSA_CERT:
1759 case KEY_DSA_CERT:
1760 case KEY_ECDSA_CERT:
1761 return 1;
1762 default:
1763 return 0;
1764 }
1765 }
1766
1767 /* Return the cert-less equivalent to a certified key type */
1768 int
1769 key_type_plain(int type)
1770 {
1771 switch (type) {
1772 case KEY_RSA_CERT_V00:
1773 case KEY_RSA_CERT:
1774 return KEY_RSA;
1775 case KEY_DSA_CERT_V00:
1776 case KEY_DSA_CERT:
1777 return KEY_DSA;
1778 case KEY_ECDSA_CERT:
1779 return KEY_ECDSA;
1780 default:
1781 return type;
1782 }
1783 }
1784
1785 /* Convert a KEY_RSA or KEY_DSA to their _CERT equivalent */
1786 int
1787 key_to_certified(Key *k, int legacy)
1788 {
1789 switch (k->type) {
1790 case KEY_RSA:
1791 k->cert = cert_new();
1792 k->type = legacy ? KEY_RSA_CERT_V00 : KEY_RSA_CERT;
1793 return 0;
1794 case KEY_DSA:
1795 k->cert = cert_new();
1796 k->type = legacy ? KEY_DSA_CERT_V00 : KEY_DSA_CERT;
1797 return 0;
1798 case KEY_ECDSA:
1799 k->cert = cert_new();
1800 k->type = KEY_ECDSA_CERT;
1801 return 0;
1802 default:
1803 error("%s: key has incorrect type %s", __func__, key_type(k));
1804 return -1;
1805 }
1806 }
1807
1808 /* Convert a KEY_RSA_CERT or KEY_DSA_CERT to their raw key equivalent */
1809 int
1810 key_drop_cert(Key *k)
1811 {
1812 switch (k->type) {
1813 case KEY_RSA_CERT_V00:
1814 case KEY_RSA_CERT:
1815 cert_free(k->cert);
1816 k->type = KEY_RSA;
1817 return 0;
1818 case KEY_DSA_CERT_V00:
1819 case KEY_DSA_CERT:
1820 cert_free(k->cert);
1821 k->type = KEY_DSA;
1822 return 0;
1823 case KEY_ECDSA_CERT:
1824 cert_free(k->cert);
1825 k->type = KEY_ECDSA;
1826 return 0;
1827 default:
1828 error("%s: key has incorrect type %s", __func__, key_type(k));
1829 return -1;
1830 }
1831 }
1832
1833 /*
1834 * Sign a KEY_RSA_CERT, KEY_DSA_CERT or KEY_ECDSA_CERT, (re-)generating
1835 * the signed certblob
1836 */
1837 int
1838 key_certify(Key *k, Key *ca)
1839 {
1840 Buffer principals;
1841 u_char *ca_blob, *sig_blob, nonce[32];
1842 u_int i, ca_len, sig_len;
1843
1844 if (k->cert == NULL) {
1845 error("%s: key lacks cert info", __func__);
1846 return -1;
1847 }
1848
1849 if (!key_is_cert(k)) {
1850 error("%s: certificate has unknown type %d", __func__,
1851 k->cert->type);
1852 return -1;
1853 }
1854
1855 if (ca->type != KEY_RSA && ca->type != KEY_DSA &&
1856 ca->type != KEY_ECDSA) {
1857 error("%s: CA key has unsupported type %s", __func__,
1858 key_type(ca));
1859 return -1;
1860 }
1861
1862 key_to_blob(ca, &ca_blob, &ca_len);
1863
1864 buffer_clear(&k->cert->certblob);
1865 buffer_put_cstring(&k->cert->certblob, key_ssh_name(k));
1866
1867 /* -v01 certs put nonce first */
1868 if (!key_cert_is_legacy(k)) {
1869 arc4random_buf(&nonce, sizeof(nonce));
1870 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce));
1871 }
1872
1873 switch (k->type) {
1874 case KEY_DSA_CERT_V00:
1875 case KEY_DSA_CERT:
1876 buffer_put_bignum2(&k->cert->certblob, k->dsa->p);
1877 buffer_put_bignum2(&k->cert->certblob, k->dsa->q);
1878 buffer_put_bignum2(&k->cert->certblob, k->dsa->g);
1879 buffer_put_bignum2(&k->cert->certblob, k->dsa->pub_key);
1880 break;
1881 #ifdef OPENSSL_HAS_ECC
1882 case KEY_ECDSA_CERT:
1883 buffer_put_cstring(&k->cert->certblob,
1884 key_curve_nid_to_name(k->ecdsa_nid));
1885 buffer_put_ecpoint(&k->cert->certblob,
1886 EC_KEY_get0_group(k->ecdsa),
1887 EC_KEY_get0_public_key(k->ecdsa));
1888 break;
1889 #endif
1890 case KEY_RSA_CERT_V00:
1891 case KEY_RSA_CERT:
1892 buffer_put_bignum2(&k->cert->certblob, k->rsa->e);
1893 buffer_put_bignum2(&k->cert->certblob, k->rsa->n);
1894 break;
1895 default:
1896 error("%s: key has incorrect type %s", __func__, key_type(k));
1897 buffer_clear(&k->cert->certblob);
1898 xfree(ca_blob);
1899 return -1;
1900 }
1901
1902 /* -v01 certs have a serial number next */
1903 if (!key_cert_is_legacy(k))
1904 buffer_put_int64(&k->cert->certblob, k->cert->serial);
1905
1906 buffer_put_int(&k->cert->certblob, k->cert->type);
1907 buffer_put_cstring(&k->cert->certblob, k->cert->key_id);
1908
1909 buffer_init(&principals);
1910 for (i = 0; i < k->cert->nprincipals; i++)
1911 buffer_put_cstring(&principals, k->cert->principals[i]);
1912 buffer_put_string(&k->cert->certblob, buffer_ptr(&principals),
1913 buffer_len(&principals));
1914 buffer_free(&principals);
1915
1916 buffer_put_int64(&k->cert->certblob, k->cert->valid_after);
1917 buffer_put_int64(&k->cert->certblob, k->cert->valid_before);
1918 buffer_put_string(&k->cert->certblob,
1919 buffer_ptr(&k->cert->critical), buffer_len(&k->cert->critical));
1920
1921 /* -v01 certs have non-critical options here */
1922 if (!key_cert_is_legacy(k)) {
1923 buffer_put_string(&k->cert->certblob,
1924 buffer_ptr(&k->cert->extensions),
1925 buffer_len(&k->cert->extensions));
1926 }
1927
1928 /* -v00 certs put the nonce at the end */
1929 if (key_cert_is_legacy(k))
1930 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce));
1931
1932 buffer_put_string(&k->cert->certblob, NULL, 0); /* reserved */
1933 buffer_put_string(&k->cert->certblob, ca_blob, ca_len);
1934 xfree(ca_blob);
1935
1936 /* Sign the whole mess */
1937 if (key_sign(ca, &sig_blob, &sig_len, buffer_ptr(&k->cert->certblob),
1938 buffer_len(&k->cert->certblob)) != 0) {
1939 error("%s: signature operation failed", __func__);
1940 buffer_clear(&k->cert->certblob);
1941 return -1;
1942 }
1943 /* Append signature and we are done */
1944 buffer_put_string(&k->cert->certblob, sig_blob, sig_len);
1945 xfree(sig_blob);
1946
1947 return 0;
1948 }
1949
1950 int
1951 key_cert_check_authority(const Key *k, int want_host, int require_principal,
1952 const char *name, const char **reason)
1953 {
1954 u_int i, principal_matches;
1955 time_t now = time(NULL);
1956
1957 if (want_host) {
1958 if (k->cert->type != SSH2_CERT_TYPE_HOST) {
1959 *reason = "Certificate invalid: not a host certificate";
1960 return -1;
1961 }
1962 } else {
1963 if (k->cert->type != SSH2_CERT_TYPE_USER) {
1964 *reason = "Certificate invalid: not a user certificate";
1965 return -1;
1966 }
1967 }
1968 if (now < 0) {
1969 error("%s: system clock lies before epoch", __func__);
1970 *reason = "Certificate invalid: not yet valid";
1971 return -1;
1972 }
1973 if ((u_int64_t)now < k->cert->valid_after) {
1974 *reason = "Certificate invalid: not yet valid";
1975 return -1;
1976 }
1977 if ((u_int64_t)now >= k->cert->valid_before) {
1978 *reason = "Certificate invalid: expired";
1979 return -1;
1980 }
1981 if (k->cert->nprincipals == 0) {
1982 if (require_principal) {
1983 *reason = "Certificate lacks principal list";
1984 return -1;
1985 }
1986 } else if (name != NULL) {
1987 principal_matches = 0;
1988 for (i = 0; i < k->cert->nprincipals; i++) {
1989 if (strcmp(name, k->cert->principals[i]) == 0) {
1990 principal_matches = 1;
1991 break;
1992 }
1993 }
1994 if (!principal_matches) {
1995 *reason = "Certificate invalid: name is not a listed "
1996 "principal";
1997 return -1;
1998 }
1999 }
2000 return 0;
2001 }
2002
2003 int
2004 key_cert_is_legacy(Key *k)
2005 {
2006 switch (k->type) {
2007 case KEY_DSA_CERT_V00:
2008 case KEY_RSA_CERT_V00:
2009 return 1;
2010 default:
2011 return 0;
2012 }
2013 }
2014
2015 /* XXX: these are really begging for a table-driven approach */
2016 int
2017 key_curve_name_to_nid(const char *name)
2018 {
2019 #ifdef OPENSSL_HAS_ECC
2020 if (strcmp(name, "nistp256") == 0)
2021 return NID_X9_62_prime256v1;
2022 else if (strcmp(name, "nistp384") == 0)
2023 return NID_secp384r1;
2024 else if (strcmp(name, "nistp521") == 0)
2025 return NID_secp521r1;
2026 #endif
2027
2028 debug("%s: unsupported EC curve name \"%.100s\"", __func__, name);
2029 return -1;
2030 }
2031
2032 u_int
2033 key_curve_nid_to_bits(int nid)
2034 {
2035 switch (nid) {
2036 #ifdef OPENSSL_HAS_ECC
2037 case NID_X9_62_prime256v1:
2038 return 256;
2039 case NID_secp384r1:
2040 return 384;
2041 case NID_secp521r1:
2042 return 521;
2043 #endif
2044 default:
2045 error("%s: unsupported EC curve nid %d", __func__, nid);
2046 return 0;
2047 }
2048 }
2049
2050 const char *
2051 key_curve_nid_to_name(int nid)
2052 {
2053 #ifdef OPENSSL_HAS_ECC
2054 if (nid == NID_X9_62_prime256v1)
2055 return "nistp256";
2056 else if (nid == NID_secp384r1)
2057 return "nistp384";
2058 else if (nid == NID_secp521r1)
2059 return "nistp521";
2060 #endif
2061 error("%s: unsupported EC curve nid %d", __func__, nid);
2062 return NULL;
2063 }
2064
2065 #ifdef OPENSSL_HAS_ECC
2066 const EVP_MD *
2067 key_ec_nid_to_evpmd(int nid)
2068 {
2069 int kbits = key_curve_nid_to_bits(nid);
2070
2071 if (kbits == 0)
2072 fatal("%s: invalid nid %d", __func__, nid);
2073 /* RFC5656 section 6.2.1 */
2074 if (kbits <= 256)
2075 return EVP_sha256();
2076 else if (kbits <= 384)
2077 return EVP_sha384();
2078 else
2079 return EVP_sha512();
2080 }
2081
2082 int
2083 key_ec_validate_public(const EC_GROUP *group, const EC_POINT *public)
2084 {
2085 BN_CTX *bnctx;
2086 EC_POINT *nq = NULL;
2087 BIGNUM *order, *x, *y, *tmp;
2088 int ret = -1;
2089
2090 if ((bnctx = BN_CTX_new()) == NULL)
2091 fatal("%s: BN_CTX_new failed", __func__);
2092 BN_CTX_start(bnctx);
2093
2094 /*
2095 * We shouldn't ever hit this case because bignum_get_ecpoint()
2096 * refuses to load GF2m points.
2097 */
2098 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
2099 NID_X9_62_prime_field) {
2100 error("%s: group is not a prime field", __func__);
2101 goto out;
2102 }
2103
2104 /* Q != infinity */
2105 if (EC_POINT_is_at_infinity(group, public)) {
2106 error("%s: received degenerate public key (infinity)",
2107 __func__);
2108 goto out;
2109 }
2110
2111 if ((x = BN_CTX_get(bnctx)) == NULL ||
2112 (y = BN_CTX_get(bnctx)) == NULL ||
2113 (order = BN_CTX_get(bnctx)) == NULL ||
2114 (tmp = BN_CTX_get(bnctx)) == NULL)
2115 fatal("%s: BN_CTX_get failed", __func__);
2116
2117 /* log2(x) > log2(order)/2, log2(y) > log2(order)/2 */
2118 if (EC_GROUP_get_order(group, order, bnctx) != 1)
2119 fatal("%s: EC_GROUP_get_order failed", __func__);
2120 if (EC_POINT_get_affine_coordinates_GFp(group, public,
2121 x, y, bnctx) != 1)
2122 fatal("%s: EC_POINT_get_affine_coordinates_GFp", __func__);
2123 if (BN_num_bits(x) <= BN_num_bits(order) / 2) {
2124 error("%s: public key x coordinate too small: "
2125 "bits(x) = %d, bits(order)/2 = %d", __func__,
2126 BN_num_bits(x), BN_num_bits(order) / 2);
2127 goto out;
2128 }
2129 if (BN_num_bits(y) <= BN_num_bits(order) / 2) {
2130 error("%s: public key y coordinate too small: "
2131 "bits(y) = %d, bits(order)/2 = %d", __func__,
2132 BN_num_bits(x), BN_num_bits(order) / 2);
2133 goto out;
2134 }
2135
2136 /* nQ == infinity (n == order of subgroup) */
2137 if ((nq = EC_POINT_new(group)) == NULL)
2138 fatal("%s: BN_CTX_tmp failed", __func__);
2139 if (EC_POINT_mul(group, nq, NULL, public, order, bnctx) != 1)
2140 fatal("%s: EC_GROUP_mul failed", __func__);
2141 if (EC_POINT_is_at_infinity(group, nq) != 1) {
2142 error("%s: received degenerate public key (nQ != infinity)",
2143 __func__);
2144 goto out;
2145 }
2146
2147 /* x < order - 1, y < order - 1 */
2148 if (!BN_sub(tmp, order, BN_value_one()))
2149 fatal("%s: BN_sub failed", __func__);
2150 if (BN_cmp(x, tmp) >= 0) {
2151 error("%s: public key x coordinate >= group order - 1",
2152 __func__);
2153 goto out;
2154 }
2155 if (BN_cmp(y, tmp) >= 0) {
2156 error("%s: public key y coordinate >= group order - 1",
2157 __func__);
2158 goto out;
2159 }
2160 ret = 0;
2161 out:
2162 BN_CTX_free(bnctx);
2163 EC_POINT_free(nq);
2164 return ret;
2165 }
2166
2167 int
2168 key_ec_validate_private(const EC_KEY *key)
2169 {
2170 BN_CTX *bnctx;
2171 BIGNUM *order, *tmp;
2172 int ret = -1;
2173
2174 if ((bnctx = BN_CTX_new()) == NULL)
2175 fatal("%s: BN_CTX_new failed", __func__);
2176 BN_CTX_start(bnctx);
2177
2178 if ((order = BN_CTX_get(bnctx)) == NULL ||
2179 (tmp = BN_CTX_get(bnctx)) == NULL)
2180 fatal("%s: BN_CTX_get failed", __func__);
2181
2182 /* log2(private) > log2(order)/2 */
2183 if (EC_GROUP_get_order(EC_KEY_get0_group(key), order, bnctx) != 1)
2184 fatal("%s: EC_GROUP_get_order failed", __func__);
2185 if (BN_num_bits(EC_KEY_get0_private_key(key)) <=
2186 BN_num_bits(order) / 2) {
2187 error("%s: private key too small: "
2188 "bits(y) = %d, bits(order)/2 = %d", __func__,
2189 BN_num_bits(EC_KEY_get0_private_key(key)),
2190 BN_num_bits(order) / 2);
2191 goto out;
2192 }
2193
2194 /* private < order - 1 */
2195 if (!BN_sub(tmp, order, BN_value_one()))
2196 fatal("%s: BN_sub failed", __func__);
2197 if (BN_cmp(EC_KEY_get0_private_key(key), tmp) >= 0) {
2198 error("%s: private key >= group order - 1", __func__);
2199 goto out;
2200 }
2201 ret = 0;
2202 out:
2203 BN_CTX_free(bnctx);
2204 return ret;
2205 }
2206
2207 #if defined(DEBUG_KEXECDH) || defined(DEBUG_PK)
2208 void
2209 key_dump_ec_point(const EC_GROUP *group, const EC_POINT *point)
2210 {
2211 BIGNUM *x, *y;
2212 BN_CTX *bnctx;
2213
2214 if (point == NULL) {
2215 fputs("point=(NULL)\n", stderr);
2216 return;
2217 }
2218 if ((bnctx = BN_CTX_new()) == NULL)
2219 fatal("%s: BN_CTX_new failed", __func__);
2220 BN_CTX_start(bnctx);
2221 if ((x = BN_CTX_get(bnctx)) == NULL || (y = BN_CTX_get(bnctx)) == NULL)
2222 fatal("%s: BN_CTX_get failed", __func__);
2223 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
2224 NID_X9_62_prime_field)
2225 fatal("%s: group is not a prime field", __func__);
2226 if (EC_POINT_get_affine_coordinates_GFp(group, point, x, y, bnctx) != 1)
2227 fatal("%s: EC_POINT_get_affine_coordinates_GFp", __func__);
2228 fputs("x=", stderr);
2229 BN_print_fp(stderr, x);
2230 fputs("\ny=", stderr);
2231 BN_print_fp(stderr, y);
2232 fputs("\n", stderr);
2233 BN_CTX_free(bnctx);
2234 }
2235
2236 void
2237 key_dump_ec_key(const EC_KEY *key)
2238 {
2239 const BIGNUM *exponent;
2240
2241 key_dump_ec_point(EC_KEY_get0_group(key), EC_KEY_get0_public_key(key));
2242 fputs("exponent=", stderr);
2243 if ((exponent = EC_KEY_get0_private_key(key)) == NULL)
2244 fputs("(NULL)", stderr);
2245 else
2246 BN_print_fp(stderr, EC_KEY_get0_private_key(key));
2247 fputs("\n", stderr);
2248 }
2249 #endif /* defined(DEBUG_KEXECDH) || defined(DEBUG_PK) */
2250 #endif /* OPENSSL_HAS_ECC */
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