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- (dtucker) [platform.c session.c] Move the getluid call out of session.c and
[openssh-git.git] / key.c
blob1defb1132e82f949578173ca64112ec214236692
1 /* $OpenBSD: key.c,v 1.95 2010/11/10 01:33:07 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 = RSA_new();
1017 BIGNUM *f4 = BN_new();
1018
1019 if (private == NULL)
1020 fatal("%s: RSA_new failed", __func__);
1021 if (f4 == NULL)
1022 fatal("%s: BN_new failed", __func__);
1023 if (!BN_set_word(f4, RSA_F4))
1024 fatal("%s: BN_new failed", __func__);
1025 if (!RSA_generate_key_ex(private, bits, f4, NULL))
1026 fatal("%s: key generation failed.", __func__);
1027 BN_free(f4);
1028 return private;
1029 }
1030
1031 static DSA*
1032 dsa_generate_private_key(u_int bits)
1033 {
1034 DSA *private = DSA_new();
1035
1036 if (private == NULL)
1037 fatal("%s: DSA_new failed", __func__);
1038 if (!DSA_generate_parameters_ex(private, bits, NULL, 0, NULL,
1039 NULL, NULL))
1040 fatal("%s: DSA_generate_parameters failed", __func__);
1041 if (!DSA_generate_key(private))
1042 fatal("%s: DSA_generate_key failed.", __func__);
1043 return private;
1044 }
1045
1046 int
1047 key_ecdsa_bits_to_nid(int bits)
1048 {
1049 switch (bits) {
1050 #ifdef OPENSSL_HAS_ECC
1051 case 256:
1052 return NID_X9_62_prime256v1;
1053 case 384:
1054 return NID_secp384r1;
1055 case 521:
1056 return NID_secp521r1;
1057 #endif
1058 default:
1059 return -1;
1060 }
1061 }
1062
1063 #ifdef OPENSSL_HAS_ECC
1064 int
1065 key_ecdsa_key_to_nid(EC_KEY *k)
1066 {
1067 EC_GROUP *eg;
1068 int nids[] = {
1069 NID_X9_62_prime256v1,
1070 NID_secp384r1,
1071 NID_secp521r1,
1072 -1
1073 };
1074 int nid;
1075 u_int i;
1076 BN_CTX *bnctx;
1077 const EC_GROUP *g = EC_KEY_get0_group(k);
1078
1079 /*
1080 * The group may be stored in a ASN.1 encoded private key in one of two
1081 * ways: as a "named group", which is reconstituted by ASN.1 object ID
1082 * or explicit group parameters encoded into the key blob. Only the
1083 * "named group" case sets the group NID for us, but we can figure
1084 * it out for the other case by comparing against all the groups that
1085 * are supported.
1086 */
1087 if ((nid = EC_GROUP_get_curve_name(g)) > 0)
1088 return nid;
1089 if ((bnctx = BN_CTX_new()) == NULL)
1090 fatal("%s: BN_CTX_new() failed", __func__);
1091 for (i = 0; nids[i] != -1; i++) {
1092 if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL)
1093 fatal("%s: EC_GROUP_new_by_curve_name failed",
1094 __func__);
1095 if (EC_GROUP_cmp(g, eg, bnctx) == 0)
1096 break;
1097 EC_GROUP_free(eg);
1098 }
1099 BN_CTX_free(bnctx);
1100 debug3("%s: nid = %d", __func__, nids[i]);
1101 if (nids[i] != -1) {
1102 /* Use the group with the NID attached */
1103 EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE);
1104 if (EC_KEY_set_group(k, eg) != 1)
1105 fatal("%s: EC_KEY_set_group", __func__);
1106 }
1107 return nids[i];
1108 }
1109
1110 static EC_KEY*
1111 ecdsa_generate_private_key(u_int bits, int *nid)
1112 {
1113 EC_KEY *private;
1114
1115 if ((*nid = key_ecdsa_bits_to_nid(bits)) == -1)
1116 fatal("%s: invalid key length", __func__);
1117 if ((private = EC_KEY_new_by_curve_name(*nid)) == NULL)
1118 fatal("%s: EC_KEY_new_by_curve_name failed", __func__);
1119 if (EC_KEY_generate_key(private) != 1)
1120 fatal("%s: EC_KEY_generate_key failed", __func__);
1121 EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE);
1122 return private;
1123 }
1124 #endif /* OPENSSL_HAS_ECC */
1125
1126 Key *
1127 key_generate(int type, u_int bits)
1128 {
1129 Key *k = key_new(KEY_UNSPEC);
1130 switch (type) {
1131 case KEY_DSA:
1132 k->dsa = dsa_generate_private_key(bits);
1133 break;
1134 #ifdef OPENSSL_HAS_ECC
1135 case KEY_ECDSA:
1136 k->ecdsa = ecdsa_generate_private_key(bits, &k->ecdsa_nid);
1137 break;
1138 #endif
1139 case KEY_RSA:
1140 case KEY_RSA1:
1141 k->rsa = rsa_generate_private_key(bits);
1142 break;
1143 case KEY_RSA_CERT_V00:
1144 case KEY_DSA_CERT_V00:
1145 case KEY_RSA_CERT:
1146 case KEY_DSA_CERT:
1147 fatal("key_generate: cert keys cannot be generated directly");
1148 default:
1149 fatal("key_generate: unknown type %d", type);
1150 }
1151 k->type = type;
1152 return k;
1153 }
1154
1155 void
1156 key_cert_copy(const Key *from_key, struct Key *to_key)
1157 {
1158 u_int i;
1159 const struct KeyCert *from;
1160 struct KeyCert *to;
1161
1162 if (to_key->cert != NULL) {
1163 cert_free(to_key->cert);
1164 to_key->cert = NULL;
1165 }
1166
1167 if ((from = from_key->cert) == NULL)
1168 return;
1169
1170 to = to_key->cert = cert_new();
1171
1172 buffer_append(&to->certblob, buffer_ptr(&from->certblob),
1173 buffer_len(&from->certblob));
1174
1175 buffer_append(&to->critical,
1176 buffer_ptr(&from->critical), buffer_len(&from->critical));
1177 buffer_append(&to->extensions,
1178 buffer_ptr(&from->extensions), buffer_len(&from->extensions));
1179
1180 to->serial = from->serial;
1181 to->type = from->type;
1182 to->key_id = from->key_id == NULL ? NULL : xstrdup(from->key_id);
1183 to->valid_after = from->valid_after;
1184 to->valid_before = from->valid_before;
1185 to->signature_key = from->signature_key == NULL ?
1186 NULL : key_from_private(from->signature_key);
1187
1188 to->nprincipals = from->nprincipals;
1189 if (to->nprincipals > CERT_MAX_PRINCIPALS)
1190 fatal("%s: nprincipals (%u) > CERT_MAX_PRINCIPALS (%u)",
1191 __func__, to->nprincipals, CERT_MAX_PRINCIPALS);
1192 if (to->nprincipals > 0) {
1193 to->principals = xcalloc(from->nprincipals,
1194 sizeof(*to->principals));
1195 for (i = 0; i < to->nprincipals; i++)
1196 to->principals[i] = xstrdup(from->principals[i]);
1197 }
1198 }
1199
1200 Key *
1201 key_from_private(const Key *k)
1202 {
1203 Key *n = NULL;
1204 switch (k->type) {
1205 case KEY_DSA:
1206 case KEY_DSA_CERT_V00:
1207 case KEY_DSA_CERT:
1208 n = key_new(k->type);
1209 if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) ||
1210 (BN_copy(n->dsa->q, k->dsa->q) == NULL) ||
1211 (BN_copy(n->dsa->g, k->dsa->g) == NULL) ||
1212 (BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL))
1213 fatal("key_from_private: BN_copy failed");
1214 break;
1215 #ifdef OPENSSL_HAS_ECC
1216 case KEY_ECDSA:
1217 case KEY_ECDSA_CERT:
1218 n = key_new(k->type);
1219 n->ecdsa_nid = k->ecdsa_nid;
1220 if ((n->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid)) == NULL)
1221 fatal("%s: EC_KEY_new_by_curve_name failed", __func__);
1222 if (EC_KEY_set_public_key(n->ecdsa,
1223 EC_KEY_get0_public_key(k->ecdsa)) != 1)
1224 fatal("%s: EC_KEY_set_public_key failed", __func__);
1225 break;
1226 #endif
1227 case KEY_RSA:
1228 case KEY_RSA1:
1229 case KEY_RSA_CERT_V00:
1230 case KEY_RSA_CERT:
1231 n = key_new(k->type);
1232 if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) ||
1233 (BN_copy(n->rsa->e, k->rsa->e) == NULL))
1234 fatal("key_from_private: BN_copy failed");
1235 break;
1236 default:
1237 fatal("key_from_private: unknown type %d", k->type);
1238 break;
1239 }
1240 if (key_is_cert(k))
1241 key_cert_copy(k, n);
1242 return n;
1243 }
1244
1245 int
1246 key_type_from_name(char *name)
1247 {
1248 if (strcmp(name, "rsa1") == 0) {
1249 return KEY_RSA1;
1250 } else if (strcmp(name, "rsa") == 0) {
1251 return KEY_RSA;
1252 } else if (strcmp(name, "dsa") == 0) {
1253 return KEY_DSA;
1254 } else if (strcmp(name, "ssh-rsa") == 0) {
1255 return KEY_RSA;
1256 } else if (strcmp(name, "ssh-dss") == 0) {
1257 return KEY_DSA;
1258 #ifdef OPENSSL_HAS_ECC
1259 } else if (strcmp(name, "ecdsa") == 0 ||
1260 strcmp(name, "ecdsa-sha2-nistp256") == 0 ||
1261 strcmp(name, "ecdsa-sha2-nistp384") == 0 ||
1262 strcmp(name, "ecdsa-sha2-nistp521") == 0) {
1263 return KEY_ECDSA;
1264 #endif
1265 } else if (strcmp(name, "ssh-rsa-cert-v00@openssh.com") == 0) {
1266 return KEY_RSA_CERT_V00;
1267 } else if (strcmp(name, "ssh-dss-cert-v00@openssh.com") == 0) {
1268 return KEY_DSA_CERT_V00;
1269 } else if (strcmp(name, "ssh-rsa-cert-v01@openssh.com") == 0) {
1270 return KEY_RSA_CERT;
1271 } else if (strcmp(name, "ssh-dss-cert-v01@openssh.com") == 0) {
1272 return KEY_DSA_CERT;
1273 #ifdef OPENSSL_HAS_ECC
1274 } else if (strcmp(name, "ecdsa-sha2-nistp256-cert-v01@openssh.com") == 0 ||
1275 strcmp(name, "ecdsa-sha2-nistp384-cert-v01@openssh.com") == 0 ||
1276 strcmp(name, "ecdsa-sha2-nistp521-cert-v01@openssh.com") == 0) {
1277 return KEY_ECDSA_CERT;
1278 #endif
1279 }
1280
1281 debug2("key_type_from_name: unknown key type '%s'", name);
1282 return KEY_UNSPEC;
1283 }
1284
1285 int
1286 key_ecdsa_nid_from_name(const char *name)
1287 {
1288 #ifdef OPENSSL_HAS_ECC
1289 if (strcmp(name, "ecdsa-sha2-nistp256") == 0 ||
1290 strcmp(name, "ecdsa-sha2-nistp256-cert-v01@openssh.com") == 0)
1291 return NID_X9_62_prime256v1;
1292 if (strcmp(name, "ecdsa-sha2-nistp384") == 0 ||
1293 strcmp(name, "ecdsa-sha2-nistp384-cert-v01@openssh.com") == 0)
1294 return NID_secp384r1;
1295 if (strcmp(name, "ecdsa-sha2-nistp521") == 0 ||
1296 strcmp(name, "ecdsa-sha2-nistp521-cert-v01@openssh.com") == 0)
1297 return NID_secp521r1;
1298 #endif /* OPENSSL_HAS_ECC */
1299
1300 debug2("%s: unknown/non-ECDSA key type '%s'", __func__, name);
1301 return -1;
1302 }
1303
1304 int
1305 key_names_valid2(const char *names)
1306 {
1307 char *s, *cp, *p;
1308
1309 if (names == NULL || strcmp(names, "") == 0)
1310 return 0;
1311 s = cp = xstrdup(names);
1312 for ((p = strsep(&cp, ",")); p && *p != '\0';
1313 (p = strsep(&cp, ","))) {
1314 switch (key_type_from_name(p)) {
1315 case KEY_RSA1:
1316 case KEY_UNSPEC:
1317 xfree(s);
1318 return 0;
1319 }
1320 }
1321 debug3("key names ok: [%s]", names);
1322 xfree(s);
1323 return 1;
1324 }
1325
1326 static int
1327 cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
1328 {
1329 u_char *principals, *critical, *exts, *sig_key, *sig;
1330 u_int signed_len, plen, clen, sklen, slen, kidlen, elen;
1331 Buffer tmp;
1332 char *principal;
1333 int ret = -1;
1334 int v00 = key->type == KEY_DSA_CERT_V00 ||
1335 key->type == KEY_RSA_CERT_V00;
1336
1337 buffer_init(&tmp);
1338
1339 /* Copy the entire key blob for verification and later serialisation */
1340 buffer_append(&key->cert->certblob, blob, blen);
1341
1342 elen = 0; /* Not touched for v00 certs */
1343 principals = exts = critical = sig_key = sig = NULL;
1344 if ((!v00 && buffer_get_int64_ret(&key->cert->serial, b) != 0) ||
1345 buffer_get_int_ret(&key->cert->type, b) != 0 ||
1346 (key->cert->key_id = buffer_get_cstring_ret(b, &kidlen)) == NULL ||
1347 (principals = buffer_get_string_ret(b, &plen)) == NULL ||
1348 buffer_get_int64_ret(&key->cert->valid_after, b) != 0 ||
1349 buffer_get_int64_ret(&key->cert->valid_before, b) != 0 ||
1350 (critical = buffer_get_string_ret(b, &clen)) == NULL ||
1351 (!v00 && (exts = buffer_get_string_ret(b, &elen)) == NULL) ||
1352 (v00 && buffer_get_string_ptr_ret(b, NULL) == NULL) || /* nonce */
1353 buffer_get_string_ptr_ret(b, NULL) == NULL || /* reserved */
1354 (sig_key = buffer_get_string_ret(b, &sklen)) == NULL) {
1355 error("%s: parse error", __func__);
1356 goto out;
1357 }
1358
1359 if (kidlen != strlen(key->cert->key_id)) {
1360 error("%s: key ID contains \\0 character", __func__);
1361 goto out;
1362 }
1363
1364 /* Signature is left in the buffer so we can calculate this length */
1365 signed_len = buffer_len(&key->cert->certblob) - buffer_len(b);
1366
1367 if ((sig = buffer_get_string_ret(b, &slen)) == NULL) {
1368 error("%s: parse error", __func__);
1369 goto out;
1370 }
1371
1372 if (key->cert->type != SSH2_CERT_TYPE_USER &&
1373 key->cert->type != SSH2_CERT_TYPE_HOST) {
1374 error("Unknown certificate type %u", key->cert->type);
1375 goto out;
1376 }
1377
1378 buffer_append(&tmp, principals, plen);
1379 while (buffer_len(&tmp) > 0) {
1380 if (key->cert->nprincipals >= CERT_MAX_PRINCIPALS) {
1381 error("%s: Too many principals", __func__);
1382 goto out;
1383 }
1384 if ((principal = buffer_get_cstring_ret(&tmp, &plen)) == NULL) {
1385 error("%s: Principals data invalid", __func__);
1386 goto out;
1387 }
1388 key->cert->principals = xrealloc(key->cert->principals,
1389 key->cert->nprincipals + 1, sizeof(*key->cert->principals));
1390 key->cert->principals[key->cert->nprincipals++] = principal;
1391 }
1392
1393 buffer_clear(&tmp);
1394
1395 buffer_append(&key->cert->critical, critical, clen);
1396 buffer_append(&tmp, critical, clen);
1397 /* validate structure */
1398 while (buffer_len(&tmp) != 0) {
1399 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL ||
1400 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) {
1401 error("%s: critical option data invalid", __func__);
1402 goto out;
1403 }
1404 }
1405 buffer_clear(&tmp);
1406
1407 buffer_append(&key->cert->extensions, exts, elen);
1408 buffer_append(&tmp, exts, elen);
1409 /* validate structure */
1410 while (buffer_len(&tmp) != 0) {
1411 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL ||
1412 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) {
1413 error("%s: extension data invalid", __func__);
1414 goto out;
1415 }
1416 }
1417 buffer_clear(&tmp);
1418
1419 if ((key->cert->signature_key = key_from_blob(sig_key,
1420 sklen)) == NULL) {
1421 error("%s: Signature key invalid", __func__);
1422 goto out;
1423 }
1424 if (key->cert->signature_key->type != KEY_RSA &&
1425 key->cert->signature_key->type != KEY_DSA &&
1426 key->cert->signature_key->type != KEY_ECDSA) {
1427 error("%s: Invalid signature key type %s (%d)", __func__,
1428 key_type(key->cert->signature_key),
1429 key->cert->signature_key->type);
1430 goto out;
1431 }
1432
1433 switch (key_verify(key->cert->signature_key, sig, slen,
1434 buffer_ptr(&key->cert->certblob), signed_len)) {
1435 case 1:
1436 ret = 0;
1437 break; /* Good signature */
1438 case 0:
1439 error("%s: Invalid signature on certificate", __func__);
1440 goto out;
1441 case -1:
1442 error("%s: Certificate signature verification failed",
1443 __func__);
1444 goto out;
1445 }
1446
1447 out:
1448 buffer_free(&tmp);
1449 if (principals != NULL)
1450 xfree(principals);
1451 if (critical != NULL)
1452 xfree(critical);
1453 if (exts != NULL)
1454 xfree(exts);
1455 if (sig_key != NULL)
1456 xfree(sig_key);
1457 if (sig != NULL)
1458 xfree(sig);
1459 return ret;
1460 }
1461
1462 Key *
1463 key_from_blob(const u_char *blob, u_int blen)
1464 {
1465 Buffer b;
1466 int rlen, type;
1467 char *ktype = NULL, *curve = NULL;
1468 Key *key = NULL;
1469 #ifdef OPENSSL_HAS_ECC
1470 EC_POINT *q = NULL;
1471 int nid = -1;
1472 #endif
1473
1474 #ifdef DEBUG_PK
1475 dump_base64(stderr, blob, blen);
1476 #endif
1477 buffer_init(&b);
1478 buffer_append(&b, blob, blen);
1479 if ((ktype = buffer_get_cstring_ret(&b, NULL)) == NULL) {
1480 error("key_from_blob: can't read key type");
1481 goto out;
1482 }
1483
1484 type = key_type_from_name(ktype);
1485 #ifdef OPENSSL_HAS_ECC
1486 if (key_type_plain(type) == KEY_ECDSA)
1487 nid = key_ecdsa_nid_from_name(ktype);
1488 #endif
1489
1490 switch (type) {
1491 case KEY_RSA_CERT:
1492 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */
1493 /* FALLTHROUGH */
1494 case KEY_RSA:
1495 case KEY_RSA_CERT_V00:
1496 key = key_new(type);
1497 if (buffer_get_bignum2_ret(&b, key->rsa->e) == -1 ||
1498 buffer_get_bignum2_ret(&b, key->rsa->n) == -1) {
1499 error("key_from_blob: can't read rsa key");
1500 badkey:
1501 key_free(key);
1502 key = NULL;
1503 goto out;
1504 }
1505 #ifdef DEBUG_PK
1506 RSA_print_fp(stderr, key->rsa, 8);
1507 #endif
1508 break;
1509 case KEY_DSA_CERT:
1510 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */
1511 /* FALLTHROUGH */
1512 case KEY_DSA:
1513 case KEY_DSA_CERT_V00:
1514 key = key_new(type);
1515 if (buffer_get_bignum2_ret(&b, key->dsa->p) == -1 ||
1516 buffer_get_bignum2_ret(&b, key->dsa->q) == -1 ||
1517 buffer_get_bignum2_ret(&b, key->dsa->g) == -1 ||
1518 buffer_get_bignum2_ret(&b, key->dsa->pub_key) == -1) {
1519 error("key_from_blob: can't read dsa key");
1520 goto badkey;
1521 }
1522 #ifdef DEBUG_PK
1523 DSA_print_fp(stderr, key->dsa, 8);
1524 #endif
1525 break;
1526 #ifdef OPENSSL_HAS_ECC
1527 case KEY_ECDSA_CERT:
1528 (void)buffer_get_string_ptr_ret(&b, NULL); /* Skip nonce */
1529 /* FALLTHROUGH */
1530 case KEY_ECDSA:
1531 key = key_new(type);
1532 key->ecdsa_nid = nid;
1533 if ((curve = buffer_get_string_ret(&b, NULL)) == NULL) {
1534 error("key_from_blob: can't read ecdsa curve");
1535 goto badkey;
1536 }
1537 if (key->ecdsa_nid != key_curve_name_to_nid(curve)) {
1538 error("key_from_blob: ecdsa curve doesn't match type");
1539 goto badkey;
1540 }
1541 if (key->ecdsa != NULL)
1542 EC_KEY_free(key->ecdsa);
1543 if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid))
1544 == NULL)
1545 fatal("key_from_blob: EC_KEY_new_by_curve_name failed");
1546 if ((q = EC_POINT_new(EC_KEY_get0_group(key->ecdsa))) == NULL)
1547 fatal("key_from_blob: EC_POINT_new failed");
1548 if (buffer_get_ecpoint_ret(&b, EC_KEY_get0_group(key->ecdsa),
1549 q) == -1) {
1550 error("key_from_blob: can't read ecdsa key point");
1551 goto badkey;
1552 }
1553 if (key_ec_validate_public(EC_KEY_get0_group(key->ecdsa),
1554 q) != 0)
1555 goto badkey;
1556 if (EC_KEY_set_public_key(key->ecdsa, q) != 1)
1557 fatal("key_from_blob: EC_KEY_set_public_key failed");
1558 #ifdef DEBUG_PK
1559 key_dump_ec_point(EC_KEY_get0_group(key->ecdsa), q);
1560 #endif
1561 break;
1562 #endif /* OPENSSL_HAS_ECC */
1563 case KEY_UNSPEC:
1564 key = key_new(type);
1565 break;
1566 default:
1567 error("key_from_blob: cannot handle type %s", ktype);
1568 goto out;
1569 }
1570 if (key_is_cert(key) && cert_parse(&b, key, blob, blen) == -1) {
1571 error("key_from_blob: can't parse cert data");
1572 goto badkey;
1573 }
1574 rlen = buffer_len(&b);
1575 if (key != NULL && rlen != 0)
1576 error("key_from_blob: remaining bytes in key blob %d", rlen);
1577 out:
1578 if (ktype != NULL)
1579 xfree(ktype);
1580 if (curve != NULL)
1581 xfree(curve);
1582 #ifdef OPENSSL_HAS_ECC
1583 if (q != NULL)
1584 EC_POINT_free(q);
1585 #endif
1586 buffer_free(&b);
1587 return key;
1588 }
1589
1590 int
1591 key_to_blob(const Key *key, u_char **blobp, u_int *lenp)
1592 {
1593 Buffer b;
1594 int len;
1595
1596 if (key == NULL) {
1597 error("key_to_blob: key == NULL");
1598 return 0;
1599 }
1600 buffer_init(&b);
1601 switch (key->type) {
1602 case KEY_DSA_CERT_V00:
1603 case KEY_RSA_CERT_V00:
1604 case KEY_DSA_CERT:
1605 case KEY_ECDSA_CERT:
1606 case KEY_RSA_CERT:
1607 /* Use the existing blob */
1608 buffer_append(&b, buffer_ptr(&key->cert->certblob),
1609 buffer_len(&key->cert->certblob));
1610 break;
1611 case KEY_DSA:
1612 buffer_put_cstring(&b, key_ssh_name(key));
1613 buffer_put_bignum2(&b, key->dsa->p);
1614 buffer_put_bignum2(&b, key->dsa->q);
1615 buffer_put_bignum2(&b, key->dsa->g);
1616 buffer_put_bignum2(&b, key->dsa->pub_key);
1617 break;
1618 #ifdef OPENSSL_HAS_ECC
1619 case KEY_ECDSA:
1620 buffer_put_cstring(&b, key_ssh_name(key));
1621 buffer_put_cstring(&b, key_curve_nid_to_name(key->ecdsa_nid));
1622 buffer_put_ecpoint(&b, EC_KEY_get0_group(key->ecdsa),
1623 EC_KEY_get0_public_key(key->ecdsa));
1624 break;
1625 #endif
1626 case KEY_RSA:
1627 buffer_put_cstring(&b, key_ssh_name(key));
1628 buffer_put_bignum2(&b, key->rsa->e);
1629 buffer_put_bignum2(&b, key->rsa->n);
1630 break;
1631 default:
1632 error("key_to_blob: unsupported key type %d", key->type);
1633 buffer_free(&b);
1634 return 0;
1635 }
1636 len = buffer_len(&b);
1637 if (lenp != NULL)
1638 *lenp = len;
1639 if (blobp != NULL) {
1640 *blobp = xmalloc(len);
1641 memcpy(*blobp, buffer_ptr(&b), len);
1642 }
1643 memset(buffer_ptr(&b), 0, len);
1644 buffer_free(&b);
1645 return len;
1646 }
1647
1648 int
1649 key_sign(
1650 const Key *key,
1651 u_char **sigp, u_int *lenp,
1652 const u_char *data, u_int datalen)
1653 {
1654 switch (key->type) {
1655 case KEY_DSA_CERT_V00:
1656 case KEY_DSA_CERT:
1657 case KEY_DSA:
1658 return ssh_dss_sign(key, sigp, lenp, data, datalen);
1659 #ifdef OPENSSL_HAS_ECC
1660 case KEY_ECDSA_CERT:
1661 case KEY_ECDSA:
1662 return ssh_ecdsa_sign(key, sigp, lenp, data, datalen);
1663 #endif
1664 case KEY_RSA_CERT_V00:
1665 case KEY_RSA_CERT:
1666 case KEY_RSA:
1667 return ssh_rsa_sign(key, sigp, lenp, data, datalen);
1668 default:
1669 error("key_sign: invalid key type %d", key->type);
1670 return -1;
1671 }
1672 }
1673
1674 /*
1675 * key_verify returns 1 for a correct signature, 0 for an incorrect signature
1676 * and -1 on error.
1677 */
1678 int
1679 key_verify(
1680 const Key *key,
1681 const u_char *signature, u_int signaturelen,
1682 const u_char *data, u_int datalen)
1683 {
1684 if (signaturelen == 0)
1685 return -1;
1686
1687 switch (key->type) {
1688 case KEY_DSA_CERT_V00:
1689 case KEY_DSA_CERT:
1690 case KEY_DSA:
1691 return ssh_dss_verify(key, signature, signaturelen, data, datalen);
1692 #ifdef OPENSSL_HAS_ECC
1693 case KEY_ECDSA_CERT:
1694 case KEY_ECDSA:
1695 return ssh_ecdsa_verify(key, signature, signaturelen, data, datalen);
1696 #endif
1697 case KEY_RSA_CERT_V00:
1698 case KEY_RSA_CERT:
1699 case KEY_RSA:
1700 return ssh_rsa_verify(key, signature, signaturelen, data, datalen);
1701 default:
1702 error("key_verify: invalid key type %d", key->type);
1703 return -1;
1704 }
1705 }
1706
1707 /* Converts a private to a public key */
1708 Key *
1709 key_demote(const Key *k)
1710 {
1711 Key *pk;
1712
1713 pk = xcalloc(1, sizeof(*pk));
1714 pk->type = k->type;
1715 pk->flags = k->flags;
1716 pk->ecdsa_nid = k->ecdsa_nid;
1717 pk->dsa = NULL;
1718 pk->ecdsa = NULL;
1719 pk->rsa = NULL;
1720
1721 switch (k->type) {
1722 case KEY_RSA_CERT_V00:
1723 case KEY_RSA_CERT:
1724 key_cert_copy(k, pk);
1725 /* FALLTHROUGH */
1726 case KEY_RSA1:
1727 case KEY_RSA:
1728 if ((pk->rsa = RSA_new()) == NULL)
1729 fatal("key_demote: RSA_new failed");
1730 if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL)
1731 fatal("key_demote: BN_dup failed");
1732 if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL)
1733 fatal("key_demote: BN_dup failed");
1734 break;
1735 case KEY_DSA_CERT_V00:
1736 case KEY_DSA_CERT:
1737 key_cert_copy(k, pk);
1738 /* FALLTHROUGH */
1739 case KEY_DSA:
1740 if ((pk->dsa = DSA_new()) == NULL)
1741 fatal("key_demote: DSA_new failed");
1742 if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL)
1743 fatal("key_demote: BN_dup failed");
1744 if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL)
1745 fatal("key_demote: BN_dup failed");
1746 if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL)
1747 fatal("key_demote: BN_dup failed");
1748 if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL)
1749 fatal("key_demote: BN_dup failed");
1750 break;
1751 #ifdef OPENSSL_HAS_ECC
1752 case KEY_ECDSA_CERT:
1753 key_cert_copy(k, pk);
1754 /* FALLTHROUGH */
1755 case KEY_ECDSA:
1756 if ((pk->ecdsa = EC_KEY_new_by_curve_name(pk->ecdsa_nid)) == NULL)
1757 fatal("key_demote: EC_KEY_new_by_curve_name failed");
1758 if (EC_KEY_set_public_key(pk->ecdsa,
1759 EC_KEY_get0_public_key(k->ecdsa)) != 1)
1760 fatal("key_demote: EC_KEY_set_public_key failed");
1761 break;
1762 #endif
1763 default:
1764 fatal("key_free: bad key type %d", k->type);
1765 break;
1766 }
1767
1768 return (pk);
1769 }
1770
1771 int
1772 key_is_cert(const Key *k)
1773 {
1774 if (k == NULL)
1775 return 0;
1776 switch (k->type) {
1777 case KEY_RSA_CERT_V00:
1778 case KEY_DSA_CERT_V00:
1779 case KEY_RSA_CERT:
1780 case KEY_DSA_CERT:
1781 case KEY_ECDSA_CERT:
1782 return 1;
1783 default:
1784 return 0;
1785 }
1786 }
1787
1788 /* Return the cert-less equivalent to a certified key type */
1789 int
1790 key_type_plain(int type)
1791 {
1792 switch (type) {
1793 case KEY_RSA_CERT_V00:
1794 case KEY_RSA_CERT:
1795 return KEY_RSA;
1796 case KEY_DSA_CERT_V00:
1797 case KEY_DSA_CERT:
1798 return KEY_DSA;
1799 case KEY_ECDSA_CERT:
1800 return KEY_ECDSA;
1801 default:
1802 return type;
1803 }
1804 }
1805
1806 /* Convert a KEY_RSA or KEY_DSA to their _CERT equivalent */
1807 int
1808 key_to_certified(Key *k, int legacy)
1809 {
1810 switch (k->type) {
1811 case KEY_RSA:
1812 k->cert = cert_new();
1813 k->type = legacy ? KEY_RSA_CERT_V00 : KEY_RSA_CERT;
1814 return 0;
1815 case KEY_DSA:
1816 k->cert = cert_new();
1817 k->type = legacy ? KEY_DSA_CERT_V00 : KEY_DSA_CERT;
1818 return 0;
1819 case KEY_ECDSA:
1820 k->cert = cert_new();
1821 k->type = KEY_ECDSA_CERT;
1822 return 0;
1823 default:
1824 error("%s: key has incorrect type %s", __func__, key_type(k));
1825 return -1;
1826 }
1827 }
1828
1829 /* Convert a KEY_RSA_CERT or KEY_DSA_CERT to their raw key equivalent */
1830 int
1831 key_drop_cert(Key *k)
1832 {
1833 switch (k->type) {
1834 case KEY_RSA_CERT_V00:
1835 case KEY_RSA_CERT:
1836 cert_free(k->cert);
1837 k->type = KEY_RSA;
1838 return 0;
1839 case KEY_DSA_CERT_V00:
1840 case KEY_DSA_CERT:
1841 cert_free(k->cert);
1842 k->type = KEY_DSA;
1843 return 0;
1844 case KEY_ECDSA_CERT:
1845 cert_free(k->cert);
1846 k->type = KEY_ECDSA;
1847 return 0;
1848 default:
1849 error("%s: key has incorrect type %s", __func__, key_type(k));
1850 return -1;
1851 }
1852 }
1853
1854 /*
1855 * Sign a KEY_RSA_CERT, KEY_DSA_CERT or KEY_ECDSA_CERT, (re-)generating
1856 * the signed certblob
1857 */
1858 int
1859 key_certify(Key *k, Key *ca)
1860 {
1861 Buffer principals;
1862 u_char *ca_blob, *sig_blob, nonce[32];
1863 u_int i, ca_len, sig_len;
1864
1865 if (k->cert == NULL) {
1866 error("%s: key lacks cert info", __func__);
1867 return -1;
1868 }
1869
1870 if (!key_is_cert(k)) {
1871 error("%s: certificate has unknown type %d", __func__,
1872 k->cert->type);
1873 return -1;
1874 }
1875
1876 if (ca->type != KEY_RSA && ca->type != KEY_DSA &&
1877 ca->type != KEY_ECDSA) {
1878 error("%s: CA key has unsupported type %s", __func__,
1879 key_type(ca));
1880 return -1;
1881 }
1882
1883 key_to_blob(ca, &ca_blob, &ca_len);
1884
1885 buffer_clear(&k->cert->certblob);
1886 buffer_put_cstring(&k->cert->certblob, key_ssh_name(k));
1887
1888 /* -v01 certs put nonce first */
1889 if (!key_cert_is_legacy(k)) {
1890 arc4random_buf(&nonce, sizeof(nonce));
1891 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce));
1892 }
1893
1894 switch (k->type) {
1895 case KEY_DSA_CERT_V00:
1896 case KEY_DSA_CERT:
1897 buffer_put_bignum2(&k->cert->certblob, k->dsa->p);
1898 buffer_put_bignum2(&k->cert->certblob, k->dsa->q);
1899 buffer_put_bignum2(&k->cert->certblob, k->dsa->g);
1900 buffer_put_bignum2(&k->cert->certblob, k->dsa->pub_key);
1901 break;
1902 #ifdef OPENSSL_HAS_ECC
1903 case KEY_ECDSA_CERT:
1904 buffer_put_cstring(&k->cert->certblob,
1905 key_curve_nid_to_name(k->ecdsa_nid));
1906 buffer_put_ecpoint(&k->cert->certblob,
1907 EC_KEY_get0_group(k->ecdsa),
1908 EC_KEY_get0_public_key(k->ecdsa));
1909 break;
1910 #endif
1911 case KEY_RSA_CERT_V00:
1912 case KEY_RSA_CERT:
1913 buffer_put_bignum2(&k->cert->certblob, k->rsa->e);
1914 buffer_put_bignum2(&k->cert->certblob, k->rsa->n);
1915 break;
1916 default:
1917 error("%s: key has incorrect type %s", __func__, key_type(k));
1918 buffer_clear(&k->cert->certblob);
1919 xfree(ca_blob);
1920 return -1;
1921 }
1922
1923 /* -v01 certs have a serial number next */
1924 if (!key_cert_is_legacy(k))
1925 buffer_put_int64(&k->cert->certblob, k->cert->serial);
1926
1927 buffer_put_int(&k->cert->certblob, k->cert->type);
1928 buffer_put_cstring(&k->cert->certblob, k->cert->key_id);
1929
1930 buffer_init(&principals);
1931 for (i = 0; i < k->cert->nprincipals; i++)
1932 buffer_put_cstring(&principals, k->cert->principals[i]);
1933 buffer_put_string(&k->cert->certblob, buffer_ptr(&principals),
1934 buffer_len(&principals));
1935 buffer_free(&principals);
1936
1937 buffer_put_int64(&k->cert->certblob, k->cert->valid_after);
1938 buffer_put_int64(&k->cert->certblob, k->cert->valid_before);
1939 buffer_put_string(&k->cert->certblob,
1940 buffer_ptr(&k->cert->critical), buffer_len(&k->cert->critical));
1941
1942 /* -v01 certs have non-critical options here */
1943 if (!key_cert_is_legacy(k)) {
1944 buffer_put_string(&k->cert->certblob,
1945 buffer_ptr(&k->cert->extensions),
1946 buffer_len(&k->cert->extensions));
1947 }
1948
1949 /* -v00 certs put the nonce at the end */
1950 if (key_cert_is_legacy(k))
1951 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce));
1952
1953 buffer_put_string(&k->cert->certblob, NULL, 0); /* reserved */
1954 buffer_put_string(&k->cert->certblob, ca_blob, ca_len);
1955 xfree(ca_blob);
1956
1957 /* Sign the whole mess */
1958 if (key_sign(ca, &sig_blob, &sig_len, buffer_ptr(&k->cert->certblob),
1959 buffer_len(&k->cert->certblob)) != 0) {
1960 error("%s: signature operation failed", __func__);
1961 buffer_clear(&k->cert->certblob);
1962 return -1;
1963 }
1964 /* Append signature and we are done */
1965 buffer_put_string(&k->cert->certblob, sig_blob, sig_len);
1966 xfree(sig_blob);
1967
1968 return 0;
1969 }
1970
1971 int
1972 key_cert_check_authority(const Key *k, int want_host, int require_principal,
1973 const char *name, const char **reason)
1974 {
1975 u_int i, principal_matches;
1976 time_t now = time(NULL);
1977
1978 if (want_host) {
1979 if (k->cert->type != SSH2_CERT_TYPE_HOST) {
1980 *reason = "Certificate invalid: not a host certificate";
1981 return -1;
1982 }
1983 } else {
1984 if (k->cert->type != SSH2_CERT_TYPE_USER) {
1985 *reason = "Certificate invalid: not a user certificate";
1986 return -1;
1987 }
1988 }
1989 if (now < 0) {
1990 error("%s: system clock lies before epoch", __func__);
1991 *reason = "Certificate invalid: not yet valid";
1992 return -1;
1993 }
1994 if ((u_int64_t)now < k->cert->valid_after) {
1995 *reason = "Certificate invalid: not yet valid";
1996 return -1;
1997 }
1998 if ((u_int64_t)now >= k->cert->valid_before) {
1999 *reason = "Certificate invalid: expired";
2000 return -1;
2001 }
2002 if (k->cert->nprincipals == 0) {
2003 if (require_principal) {
2004 *reason = "Certificate lacks principal list";
2005 return -1;
2006 }
2007 } else if (name != NULL) {
2008 principal_matches = 0;
2009 for (i = 0; i < k->cert->nprincipals; i++) {
2010 if (strcmp(name, k->cert->principals[i]) == 0) {
2011 principal_matches = 1;
2012 break;
2013 }
2014 }
2015 if (!principal_matches) {
2016 *reason = "Certificate invalid: name is not a listed "
2017 "principal";
2018 return -1;
2019 }
2020 }
2021 return 0;
2022 }
2023
2024 int
2025 key_cert_is_legacy(Key *k)
2026 {
2027 switch (k->type) {
2028 case KEY_DSA_CERT_V00:
2029 case KEY_RSA_CERT_V00:
2030 return 1;
2031 default:
2032 return 0;
2033 }
2034 }
2035
2036 /* XXX: these are really begging for a table-driven approach */
2037 int
2038 key_curve_name_to_nid(const char *name)
2039 {
2040 #ifdef OPENSSL_HAS_ECC
2041 if (strcmp(name, "nistp256") == 0)
2042 return NID_X9_62_prime256v1;
2043 else if (strcmp(name, "nistp384") == 0)
2044 return NID_secp384r1;
2045 else if (strcmp(name, "nistp521") == 0)
2046 return NID_secp521r1;
2047 #endif
2048
2049 debug("%s: unsupported EC curve name \"%.100s\"", __func__, name);
2050 return -1;
2051 }
2052
2053 u_int
2054 key_curve_nid_to_bits(int nid)
2055 {
2056 switch (nid) {
2057 #ifdef OPENSSL_HAS_ECC
2058 case NID_X9_62_prime256v1:
2059 return 256;
2060 case NID_secp384r1:
2061 return 384;
2062 case NID_secp521r1:
2063 return 521;
2064 #endif
2065 default:
2066 error("%s: unsupported EC curve nid %d", __func__, nid);
2067 return 0;
2068 }
2069 }
2070
2071 const char *
2072 key_curve_nid_to_name(int nid)
2073 {
2074 #ifdef OPENSSL_HAS_ECC
2075 if (nid == NID_X9_62_prime256v1)
2076 return "nistp256";
2077 else if (nid == NID_secp384r1)
2078 return "nistp384";
2079 else if (nid == NID_secp521r1)
2080 return "nistp521";
2081 #endif
2082 error("%s: unsupported EC curve nid %d", __func__, nid);
2083 return NULL;
2084 }
2085
2086 #ifdef OPENSSL_HAS_ECC
2087 const EVP_MD *
2088 key_ec_nid_to_evpmd(int nid)
2089 {
2090 int kbits = key_curve_nid_to_bits(nid);
2091
2092 if (kbits == 0)
2093 fatal("%s: invalid nid %d", __func__, nid);
2094 /* RFC5656 section 6.2.1 */
2095 if (kbits <= 256)
2096 return EVP_sha256();
2097 else if (kbits <= 384)
2098 return EVP_sha384();
2099 else
2100 return EVP_sha512();
2101 }
2102
2103 int
2104 key_ec_validate_public(const EC_GROUP *group, const EC_POINT *public)
2105 {
2106 BN_CTX *bnctx;
2107 EC_POINT *nq = NULL;
2108 BIGNUM *order, *x, *y, *tmp;
2109 int ret = -1;
2110
2111 if ((bnctx = BN_CTX_new()) == NULL)
2112 fatal("%s: BN_CTX_new failed", __func__);
2113 BN_CTX_start(bnctx);
2114
2115 /*
2116 * We shouldn't ever hit this case because bignum_get_ecpoint()
2117 * refuses to load GF2m points.
2118 */
2119 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
2120 NID_X9_62_prime_field) {
2121 error("%s: group is not a prime field", __func__);
2122 goto out;
2123 }
2124
2125 /* Q != infinity */
2126 if (EC_POINT_is_at_infinity(group, public)) {
2127 error("%s: received degenerate public key (infinity)",
2128 __func__);
2129 goto out;
2130 }
2131
2132 if ((x = BN_CTX_get(bnctx)) == NULL ||
2133 (y = BN_CTX_get(bnctx)) == NULL ||
2134 (order = BN_CTX_get(bnctx)) == NULL ||
2135 (tmp = BN_CTX_get(bnctx)) == NULL)
2136 fatal("%s: BN_CTX_get failed", __func__);
2137
2138 /* log2(x) > log2(order)/2, log2(y) > log2(order)/2 */
2139 if (EC_GROUP_get_order(group, order, bnctx) != 1)
2140 fatal("%s: EC_GROUP_get_order failed", __func__);
2141 if (EC_POINT_get_affine_coordinates_GFp(group, public,
2142 x, y, bnctx) != 1)
2143 fatal("%s: EC_POINT_get_affine_coordinates_GFp", __func__);
2144 if (BN_num_bits(x) <= BN_num_bits(order) / 2) {
2145 error("%s: public key x coordinate too small: "
2146 "bits(x) = %d, bits(order)/2 = %d", __func__,
2147 BN_num_bits(x), BN_num_bits(order) / 2);
2148 goto out;
2149 }
2150 if (BN_num_bits(y) <= BN_num_bits(order) / 2) {
2151 error("%s: public key y coordinate too small: "
2152 "bits(y) = %d, bits(order)/2 = %d", __func__,
2153 BN_num_bits(x), BN_num_bits(order) / 2);
2154 goto out;
2155 }
2156
2157 /* nQ == infinity (n == order of subgroup) */
2158 if ((nq = EC_POINT_new(group)) == NULL)
2159 fatal("%s: BN_CTX_tmp failed", __func__);
2160 if (EC_POINT_mul(group, nq, NULL, public, order, bnctx) != 1)
2161 fatal("%s: EC_GROUP_mul failed", __func__);
2162 if (EC_POINT_is_at_infinity(group, nq) != 1) {
2163 error("%s: received degenerate public key (nQ != infinity)",
2164 __func__);
2165 goto out;
2166 }
2167
2168 /* x < order - 1, y < order - 1 */
2169 if (!BN_sub(tmp, order, BN_value_one()))
2170 fatal("%s: BN_sub failed", __func__);
2171 if (BN_cmp(x, tmp) >= 0) {
2172 error("%s: public key x coordinate >= group order - 1",
2173 __func__);
2174 goto out;
2175 }
2176 if (BN_cmp(y, tmp) >= 0) {
2177 error("%s: public key y coordinate >= group order - 1",
2178 __func__);
2179 goto out;
2180 }
2181 ret = 0;
2182 out:
2183 BN_CTX_free(bnctx);
2184 EC_POINT_free(nq);
2185 return ret;
2186 }
2187
2188 int
2189 key_ec_validate_private(const EC_KEY *key)
2190 {
2191 BN_CTX *bnctx;
2192 BIGNUM *order, *tmp;
2193 int ret = -1;
2194
2195 if ((bnctx = BN_CTX_new()) == NULL)
2196 fatal("%s: BN_CTX_new failed", __func__);
2197 BN_CTX_start(bnctx);
2198
2199 if ((order = BN_CTX_get(bnctx)) == NULL ||
2200 (tmp = BN_CTX_get(bnctx)) == NULL)
2201 fatal("%s: BN_CTX_get failed", __func__);
2202
2203 /* log2(private) > log2(order)/2 */
2204 if (EC_GROUP_get_order(EC_KEY_get0_group(key), order, bnctx) != 1)
2205 fatal("%s: EC_GROUP_get_order failed", __func__);
2206 if (BN_num_bits(EC_KEY_get0_private_key(key)) <=
2207 BN_num_bits(order) / 2) {
2208 error("%s: private key too small: "
2209 "bits(y) = %d, bits(order)/2 = %d", __func__,
2210 BN_num_bits(EC_KEY_get0_private_key(key)),
2211 BN_num_bits(order) / 2);
2212 goto out;
2213 }
2214
2215 /* private < order - 1 */
2216 if (!BN_sub(tmp, order, BN_value_one()))
2217 fatal("%s: BN_sub failed", __func__);
2218 if (BN_cmp(EC_KEY_get0_private_key(key), tmp) >= 0) {
2219 error("%s: private key >= group order - 1", __func__);
2220 goto out;
2221 }
2222 ret = 0;
2223 out:
2224 BN_CTX_free(bnctx);
2225 return ret;
2226 }
2227
2228 #if defined(DEBUG_KEXECDH) || defined(DEBUG_PK)
2229 void
2230 key_dump_ec_point(const EC_GROUP *group, const EC_POINT *point)
2231 {
2232 BIGNUM *x, *y;
2233 BN_CTX *bnctx;
2234
2235 if (point == NULL) {
2236 fputs("point=(NULL)\n", stderr);
2237 return;
2238 }
2239 if ((bnctx = BN_CTX_new()) == NULL)
2240 fatal("%s: BN_CTX_new failed", __func__);
2241 BN_CTX_start(bnctx);
2242 if ((x = BN_CTX_get(bnctx)) == NULL || (y = BN_CTX_get(bnctx)) == NULL)
2243 fatal("%s: BN_CTX_get failed", __func__);
2244 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
2245 NID_X9_62_prime_field)
2246 fatal("%s: group is not a prime field", __func__);
2247 if (EC_POINT_get_affine_coordinates_GFp(group, point, x, y, bnctx) != 1)
2248 fatal("%s: EC_POINT_get_affine_coordinates_GFp", __func__);
2249 fputs("x=", stderr);
2250 BN_print_fp(stderr, x);
2251 fputs("\ny=", stderr);
2252 BN_print_fp(stderr, y);
2253 fputs("\n", stderr);
2254 BN_CTX_free(bnctx);
2255 }
2256
2257 void
2258 key_dump_ec_key(const EC_KEY *key)
2259 {
2260 const BIGNUM *exponent;
2261
2262 key_dump_ec_point(EC_KEY_get0_group(key), EC_KEY_get0_public_key(key));
2263 fputs("exponent=", stderr);
2264 if ((exponent = EC_KEY_get0_private_key(key)) == NULL)
2265 fputs("(NULL)", stderr);
2266 else
2267 BN_print_fp(stderr, EC_KEY_get0_private_key(key));
2268 fputs("\n", stderr);
2269 }
2270 #endif /* defined(DEBUG_KEXECDH) || defined(DEBUG_PK) */
2271 #endif /* OPENSSL_HAS_ECC */
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