?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
- (dtucker) [contrib/cygwin/ssh-host-config] Mount the Windows directory
[openssh-git.git] / key.c
blob66592c7ed19e3e0d61e4dc714cc384b311d4c44f
1 /* $OpenBSD: key.c,v 1.86 2010/03/15 19:40:02 stevesk 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 "ssh2.h"
56
57 static struct KeyCert *
58 cert_new(void)
59 {
60 struct KeyCert *cert;
61
62 cert = xcalloc(1, sizeof(*cert));
63 buffer_init(&cert->certblob);
64 buffer_init(&cert->constraints);
65 cert->key_id = NULL;
66 cert->principals = NULL;
67 cert->signature_key = NULL;
68 return cert;
69 }
70
71 Key *
72 key_new(int type)
73 {
74 Key *k;
75 RSA *rsa;
76 DSA *dsa;
77 k = xcalloc(1, sizeof(*k));
78 k->type = type;
79 k->dsa = NULL;
80 k->rsa = NULL;
81 k->cert = NULL;
82 switch (k->type) {
83 case KEY_RSA1:
84 case KEY_RSA:
85 case KEY_RSA_CERT:
86 if ((rsa = RSA_new()) == NULL)
87 fatal("key_new: RSA_new failed");
88 if ((rsa->n = BN_new()) == NULL)
89 fatal("key_new: BN_new failed");
90 if ((rsa->e = BN_new()) == NULL)
91 fatal("key_new: BN_new failed");
92 k->rsa = rsa;
93 break;
94 case KEY_DSA:
95 case KEY_DSA_CERT:
96 if ((dsa = DSA_new()) == NULL)
97 fatal("key_new: DSA_new failed");
98 if ((dsa->p = BN_new()) == NULL)
99 fatal("key_new: BN_new failed");
100 if ((dsa->q = BN_new()) == NULL)
101 fatal("key_new: BN_new failed");
102 if ((dsa->g = BN_new()) == NULL)
103 fatal("key_new: BN_new failed");
104 if ((dsa->pub_key = BN_new()) == NULL)
105 fatal("key_new: BN_new failed");
106 k->dsa = dsa;
107 break;
108 case KEY_UNSPEC:
109 break;
110 default:
111 fatal("key_new: bad key type %d", k->type);
112 break;
113 }
114
115 if (key_is_cert(k))
116 k->cert = cert_new();
117
118 return k;
119 }
120
121 void
122 key_add_private(Key *k)
123 {
124 switch (k->type) {
125 case KEY_RSA1:
126 case KEY_RSA:
127 case KEY_RSA_CERT:
128 if ((k->rsa->d = BN_new()) == NULL)
129 fatal("key_new_private: BN_new failed");
130 if ((k->rsa->iqmp = BN_new()) == NULL)
131 fatal("key_new_private: BN_new failed");
132 if ((k->rsa->q = BN_new()) == NULL)
133 fatal("key_new_private: BN_new failed");
134 if ((k->rsa->p = BN_new()) == NULL)
135 fatal("key_new_private: BN_new failed");
136 if ((k->rsa->dmq1 = BN_new()) == NULL)
137 fatal("key_new_private: BN_new failed");
138 if ((k->rsa->dmp1 = BN_new()) == NULL)
139 fatal("key_new_private: BN_new failed");
140 break;
141 case KEY_DSA:
142 case KEY_DSA_CERT:
143 if ((k->dsa->priv_key = BN_new()) == NULL)
144 fatal("key_new_private: BN_new failed");
145 break;
146 case KEY_UNSPEC:
147 break;
148 default:
149 break;
150 }
151 }
152
153 Key *
154 key_new_private(int type)
155 {
156 Key *k = key_new(type);
157
158 key_add_private(k);
159 return k;
160 }
161
162 static void
163 cert_free(struct KeyCert *cert)
164 {
165 u_int i;
166
167 buffer_free(&cert->certblob);
168 buffer_free(&cert->constraints);
169 if (cert->key_id != NULL)
170 xfree(cert->key_id);
171 for (i = 0; i < cert->nprincipals; i++)
172 xfree(cert->principals[i]);
173 if (cert->principals != NULL)
174 xfree(cert->principals);
175 if (cert->signature_key != NULL)
176 key_free(cert->signature_key);
177 }
178
179 void
180 key_free(Key *k)
181 {
182 if (k == NULL)
183 fatal("key_free: key is NULL");
184 switch (k->type) {
185 case KEY_RSA1:
186 case KEY_RSA:
187 case KEY_RSA_CERT:
188 if (k->rsa != NULL)
189 RSA_free(k->rsa);
190 k->rsa = NULL;
191 break;
192 case KEY_DSA:
193 case KEY_DSA_CERT:
194 if (k->dsa != NULL)
195 DSA_free(k->dsa);
196 k->dsa = NULL;
197 break;
198 case KEY_UNSPEC:
199 break;
200 default:
201 fatal("key_free: bad key type %d", k->type);
202 break;
203 }
204 if (key_is_cert(k)) {
205 if (k->cert != NULL)
206 cert_free(k->cert);
207 k->cert = NULL;
208 }
209
210 xfree(k);
211 }
212
213 static int
214 cert_compare(struct KeyCert *a, struct KeyCert *b)
215 {
216 if (a == NULL && b == NULL)
217 return 1;
218 if (a == NULL || b == NULL)
219 return 0;
220 if (buffer_len(&a->certblob) != buffer_len(&b->certblob))
221 return 0;
222 if (memcmp(buffer_ptr(&a->certblob), buffer_ptr(&b->certblob),
223 buffer_len(&a->certblob)) != 0)
224 return 0;
225 return 1;
226 }
227
228 /*
229 * Compare public portions of key only, allowing comparisons between
230 * certificates and plain keys too.
231 */
232 int
233 key_equal_public(const Key *a, const Key *b)
234 {
235 if (a == NULL || b == NULL ||
236 key_type_plain(a->type) != key_type_plain(b->type))
237 return 0;
238
239 switch (a->type) {
240 case KEY_RSA1:
241 case KEY_RSA_CERT:
242 case KEY_RSA:
243 return a->rsa != NULL && b->rsa != NULL &&
244 BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
245 BN_cmp(a->rsa->n, b->rsa->n) == 0;
246 case KEY_DSA_CERT:
247 case KEY_DSA:
248 return a->dsa != NULL && b->dsa != NULL &&
249 BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
250 BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
251 BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
252 BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
253 default:
254 fatal("key_equal: bad key type %d", a->type);
255 }
256 /* NOTREACHED */
257 }
258
259 int
260 key_equal(const Key *a, const Key *b)
261 {
262 if (a == NULL || b == NULL || a->type != b->type)
263 return 0;
264 if (key_is_cert(a)) {
265 if (!cert_compare(a->cert, b->cert))
266 return 0;
267 }
268 return key_equal_public(a, b);
269 }
270
271 u_char*
272 key_fingerprint_raw(Key *k, enum fp_type dgst_type, u_int *dgst_raw_length)
273 {
274 const EVP_MD *md = NULL;
275 EVP_MD_CTX ctx;
276 u_char *blob = NULL;
277 u_char *retval = NULL;
278 u_int len = 0;
279 int nlen, elen, otype;
280
281 *dgst_raw_length = 0;
282
283 switch (dgst_type) {
284 case SSH_FP_MD5:
285 md = EVP_md5();
286 break;
287 case SSH_FP_SHA1:
288 md = EVP_sha1();
289 break;
290 default:
291 fatal("key_fingerprint_raw: bad digest type %d",
292 dgst_type);
293 }
294 switch (k->type) {
295 case KEY_RSA1:
296 nlen = BN_num_bytes(k->rsa->n);
297 elen = BN_num_bytes(k->rsa->e);
298 len = nlen + elen;
299 blob = xmalloc(len);
300 BN_bn2bin(k->rsa->n, blob);
301 BN_bn2bin(k->rsa->e, blob + nlen);
302 break;
303 case KEY_DSA:
304 case KEY_RSA:
305 key_to_blob(k, &blob, &len);
306 break;
307 case KEY_DSA_CERT:
308 case KEY_RSA_CERT:
309 /* We want a fingerprint of the _key_ not of the cert */
310 otype = k->type;
311 k->type = key_type_plain(k->type);
312 key_to_blob(k, &blob, &len);
313 k->type = otype;
314 break;
315 case KEY_UNSPEC:
316 return retval;
317 default:
318 fatal("key_fingerprint_raw: bad key type %d", k->type);
319 break;
320 }
321 if (blob != NULL) {
322 retval = xmalloc(EVP_MAX_MD_SIZE);
323 EVP_DigestInit(&ctx, md);
324 EVP_DigestUpdate(&ctx, blob, len);
325 EVP_DigestFinal(&ctx, retval, dgst_raw_length);
326 memset(blob, 0, len);
327 xfree(blob);
328 } else {
329 fatal("key_fingerprint_raw: blob is null");
330 }
331 return retval;
332 }
333
334 static char *
335 key_fingerprint_hex(u_char *dgst_raw, u_int dgst_raw_len)
336 {
337 char *retval;
338 u_int i;
339
340 retval = xcalloc(1, dgst_raw_len * 3 + 1);
341 for (i = 0; i < dgst_raw_len; i++) {
342 char hex[4];
343 snprintf(hex, sizeof(hex), "%02x:", dgst_raw[i]);
344 strlcat(retval, hex, dgst_raw_len * 3 + 1);
345 }
346
347 /* Remove the trailing ':' character */
348 retval[(dgst_raw_len * 3) - 1] = '\0';
349 return retval;
350 }
351
352 static char *
353 key_fingerprint_bubblebabble(u_char *dgst_raw, u_int dgst_raw_len)
354 {
355 char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
356 char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
357 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
358 u_int i, j = 0, rounds, seed = 1;
359 char *retval;
360
361 rounds = (dgst_raw_len / 2) + 1;
362 retval = xcalloc((rounds * 6), sizeof(char));
363 retval[j++] = 'x';
364 for (i = 0; i < rounds; i++) {
365 u_int idx0, idx1, idx2, idx3, idx4;
366 if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) {
367 idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) +
368 seed) % 6;
369 idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15;
370 idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) +
371 (seed / 6)) % 6;
372 retval[j++] = vowels[idx0];
373 retval[j++] = consonants[idx1];
374 retval[j++] = vowels[idx2];
375 if ((i + 1) < rounds) {
376 idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15;
377 idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15;
378 retval[j++] = consonants[idx3];
379 retval[j++] = '-';
380 retval[j++] = consonants[idx4];
381 seed = ((seed * 5) +
382 ((((u_int)(dgst_raw[2 * i])) * 7) +
383 ((u_int)(dgst_raw[(2 * i) + 1])))) % 36;
384 }
385 } else {
386 idx0 = seed % 6;
387 idx1 = 16;
388 idx2 = seed / 6;
389 retval[j++] = vowels[idx0];
390 retval[j++] = consonants[idx1];
391 retval[j++] = vowels[idx2];
392 }
393 }
394 retval[j++] = 'x';
395 retval[j++] = '\0';
396 return retval;
397 }
398
399 /*
400 * Draw an ASCII-Art representing the fingerprint so human brain can
401 * profit from its built-in pattern recognition ability.
402 * This technique is called "random art" and can be found in some
403 * scientific publications like this original paper:
404 *
405 * "Hash Visualization: a New Technique to improve Real-World Security",
406 * Perrig A. and Song D., 1999, International Workshop on Cryptographic
407 * Techniques and E-Commerce (CrypTEC '99)
408 * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
409 *
410 * The subject came up in a talk by Dan Kaminsky, too.
411 *
412 * If you see the picture is different, the key is different.
413 * If the picture looks the same, you still know nothing.
414 *
415 * The algorithm used here is a worm crawling over a discrete plane,
416 * leaving a trace (augmenting the field) everywhere it goes.
417 * Movement is taken from dgst_raw 2bit-wise. Bumping into walls
418 * makes the respective movement vector be ignored for this turn.
419 * Graphs are not unambiguous, because circles in graphs can be
420 * walked in either direction.
421 */
422
423 /*
424 * Field sizes for the random art. Have to be odd, so the starting point
425 * can be in the exact middle of the picture, and FLDBASE should be >=8 .
426 * Else pictures would be too dense, and drawing the frame would
427 * fail, too, because the key type would not fit in anymore.
428 */
429 #define FLDBASE 8
430 #define FLDSIZE_Y (FLDBASE + 1)
431 #define FLDSIZE_X (FLDBASE * 2 + 1)
432 static char *
433 key_fingerprint_randomart(u_char *dgst_raw, u_int dgst_raw_len, const Key *k)
434 {
435 /*
436 * Chars to be used after each other every time the worm
437 * intersects with itself. Matter of taste.
438 */
439 char *augmentation_string = " .o+=*BOX@%&#/^SE";
440 char *retval, *p;
441 u_char field[FLDSIZE_X][FLDSIZE_Y];
442 u_int i, b;
443 int x, y;
444 size_t len = strlen(augmentation_string) - 1;
445
446 retval = xcalloc(1, (FLDSIZE_X + 3) * (FLDSIZE_Y + 2));
447
448 /* initialize field */
449 memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char));
450 x = FLDSIZE_X / 2;
451 y = FLDSIZE_Y / 2;
452
453 /* process raw key */
454 for (i = 0; i < dgst_raw_len; i++) {
455 int input;
456 /* each byte conveys four 2-bit move commands */
457 input = dgst_raw[i];
458 for (b = 0; b < 4; b++) {
459 /* evaluate 2 bit, rest is shifted later */
460 x += (input & 0x1) ? 1 : -1;
461 y += (input & 0x2) ? 1 : -1;
462
463 /* assure we are still in bounds */
464 x = MAX(x, 0);
465 y = MAX(y, 0);
466 x = MIN(x, FLDSIZE_X - 1);
467 y = MIN(y, FLDSIZE_Y - 1);
468
469 /* augment the field */
470 if (field[x][y] < len - 2)
471 field[x][y]++;
472 input = input >> 2;
473 }
474 }
475
476 /* mark starting point and end point*/
477 field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1;
478 field[x][y] = len;
479
480 /* fill in retval */
481 snprintf(retval, FLDSIZE_X, "+--[%4s %4u]", key_type(k), key_size(k));
482 p = strchr(retval, '\0');
483
484 /* output upper border */
485 for (i = p - retval - 1; i < FLDSIZE_X; i++)
486 *p++ = '-';
487 *p++ = '+';
488 *p++ = '\n';
489
490 /* output content */
491 for (y = 0; y < FLDSIZE_Y; y++) {
492 *p++ = '|';
493 for (x = 0; x < FLDSIZE_X; x++)
494 *p++ = augmentation_string[MIN(field[x][y], len)];
495 *p++ = '|';
496 *p++ = '\n';
497 }
498
499 /* output lower border */
500 *p++ = '+';
501 for (i = 0; i < FLDSIZE_X; i++)
502 *p++ = '-';
503 *p++ = '+';
504
505 return retval;
506 }
507
508 char *
509 key_fingerprint(Key *k, enum fp_type dgst_type, enum fp_rep dgst_rep)
510 {
511 char *retval = NULL;
512 u_char *dgst_raw;
513 u_int dgst_raw_len;
514
515 dgst_raw = key_fingerprint_raw(k, dgst_type, &dgst_raw_len);
516 if (!dgst_raw)
517 fatal("key_fingerprint: null from key_fingerprint_raw()");
518 switch (dgst_rep) {
519 case SSH_FP_HEX:
520 retval = key_fingerprint_hex(dgst_raw, dgst_raw_len);
521 break;
522 case SSH_FP_BUBBLEBABBLE:
523 retval = key_fingerprint_bubblebabble(dgst_raw, dgst_raw_len);
524 break;
525 case SSH_FP_RANDOMART:
526 retval = key_fingerprint_randomart(dgst_raw, dgst_raw_len, k);
527 break;
528 default:
529 fatal("key_fingerprint: bad digest representation %d",
530 dgst_rep);
531 break;
532 }
533 memset(dgst_raw, 0, dgst_raw_len);
534 xfree(dgst_raw);
535 return retval;
536 }
537
538 /*
539 * Reads a multiple-precision integer in decimal from the buffer, and advances
540 * the pointer. The integer must already be initialized. This function is
541 * permitted to modify the buffer. This leaves *cpp to point just beyond the
542 * last processed (and maybe modified) character. Note that this may modify
543 * the buffer containing the number.
544 */
545 static int
546 read_bignum(char **cpp, BIGNUM * value)
547 {
548 char *cp = *cpp;
549 int old;
550
551 /* Skip any leading whitespace. */
552 for (; *cp == ' ' || *cp == '\t'; cp++)
553 ;
554
555 /* Check that it begins with a decimal digit. */
556 if (*cp < '0' || *cp > '9')
557 return 0;
558
559 /* Save starting position. */
560 *cpp = cp;
561
562 /* Move forward until all decimal digits skipped. */
563 for (; *cp >= '0' && *cp <= '9'; cp++)
564 ;
565
566 /* Save the old terminating character, and replace it by \0. */
567 old = *cp;
568 *cp = 0;
569
570 /* Parse the number. */
571 if (BN_dec2bn(&value, *cpp) == 0)
572 return 0;
573
574 /* Restore old terminating character. */
575 *cp = old;
576
577 /* Move beyond the number and return success. */
578 *cpp = cp;
579 return 1;
580 }
581
582 static int
583 write_bignum(FILE *f, BIGNUM *num)
584 {
585 char *buf = BN_bn2dec(num);
586 if (buf == NULL) {
587 error("write_bignum: BN_bn2dec() failed");
588 return 0;
589 }
590 fprintf(f, " %s", buf);
591 OPENSSL_free(buf);
592 return 1;
593 }
594
595 /* returns 1 ok, -1 error */
596 int
597 key_read(Key *ret, char **cpp)
598 {
599 Key *k;
600 int success = -1;
601 char *cp, *space;
602 int len, n, type;
603 u_int bits;
604 u_char *blob;
605
606 cp = *cpp;
607
608 switch (ret->type) {
609 case KEY_RSA1:
610 /* Get number of bits. */
611 if (*cp < '0' || *cp > '9')
612 return -1; /* Bad bit count... */
613 for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
614 bits = 10 * bits + *cp - '0';
615 if (bits == 0)
616 return -1;
617 *cpp = cp;
618 /* Get public exponent, public modulus. */
619 if (!read_bignum(cpp, ret->rsa->e))
620 return -1;
621 if (!read_bignum(cpp, ret->rsa->n))
622 return -1;
623 /* validate the claimed number of bits */
624 if ((u_int)BN_num_bits(ret->rsa->n) != bits) {
625 verbose("key_read: claimed key size %d does not match "
626 "actual %d", bits, BN_num_bits(ret->rsa->n));
627 return -1;
628 }
629 success = 1;
630 break;
631 case KEY_UNSPEC:
632 case KEY_RSA:
633 case KEY_DSA:
634 case KEY_DSA_CERT:
635 case KEY_RSA_CERT:
636 space = strchr(cp, ' ');
637 if (space == NULL) {
638 debug3("key_read: missing whitespace");
639 return -1;
640 }
641 *space = '\0';
642 type = key_type_from_name(cp);
643 *space = ' ';
644 if (type == KEY_UNSPEC) {
645 debug3("key_read: missing keytype");
646 return -1;
647 }
648 cp = space+1;
649 if (*cp == '\0') {
650 debug3("key_read: short string");
651 return -1;
652 }
653 if (ret->type == KEY_UNSPEC) {
654 ret->type = type;
655 } else if (ret->type != type) {
656 /* is a key, but different type */
657 debug3("key_read: type mismatch");
658 return -1;
659 }
660 len = 2*strlen(cp);
661 blob = xmalloc(len);
662 n = uudecode(cp, blob, len);
663 if (n < 0) {
664 error("key_read: uudecode %s failed", cp);
665 xfree(blob);
666 return -1;
667 }
668 k = key_from_blob(blob, (u_int)n);
669 xfree(blob);
670 if (k == NULL) {
671 error("key_read: key_from_blob %s failed", cp);
672 return -1;
673 }
674 if (k->type != type) {
675 error("key_read: type mismatch: encoding error");
676 key_free(k);
677 return -1;
678 }
679 /*XXXX*/
680 if (key_is_cert(ret)) {
681 if (!key_is_cert(k)) {
682 error("key_read: loaded key is not a cert");
683 key_free(k);
684 return -1;
685 }
686 if (ret->cert != NULL)
687 cert_free(ret->cert);
688 ret->cert = k->cert;
689 k->cert = NULL;
690 }
691 if (key_type_plain(ret->type) == KEY_RSA) {
692 if (ret->rsa != NULL)
693 RSA_free(ret->rsa);
694 ret->rsa = k->rsa;
695 k->rsa = NULL;
696 #ifdef DEBUG_PK
697 RSA_print_fp(stderr, ret->rsa, 8);
698 #endif
699 }
700 if (key_type_plain(ret->type) == KEY_DSA) {
701 if (ret->dsa != NULL)
702 DSA_free(ret->dsa);
703 ret->dsa = k->dsa;
704 k->dsa = NULL;
705 #ifdef DEBUG_PK
706 DSA_print_fp(stderr, ret->dsa, 8);
707 #endif
708 }
709 success = 1;
710 /*XXXX*/
711 key_free(k);
712 if (success != 1)
713 break;
714 /* advance cp: skip whitespace and data */
715 while (*cp == ' ' || *cp == '\t')
716 cp++;
717 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
718 cp++;
719 *cpp = cp;
720 break;
721 default:
722 fatal("key_read: bad key type: %d", ret->type);
723 break;
724 }
725 return success;
726 }
727
728 int
729 key_write(const Key *key, FILE *f)
730 {
731 int n, success = 0;
732 u_int len, bits = 0;
733 u_char *blob;
734 char *uu;
735
736 if (key_is_cert(key)) {
737 if (key->cert == NULL) {
738 error("%s: no cert data", __func__);
739 return 0;
740 }
741 if (buffer_len(&key->cert->certblob) == 0) {
742 error("%s: no signed certificate blob", __func__);
743 return 0;
744 }
745 }
746
747 switch (key->type) {
748 case KEY_RSA1:
749 if (key->rsa == NULL)
750 return 0;
751 /* size of modulus 'n' */
752 bits = BN_num_bits(key->rsa->n);
753 fprintf(f, "%u", bits);
754 if (write_bignum(f, key->rsa->e) &&
755 write_bignum(f, key->rsa->n))
756 return 1;
757 error("key_write: failed for RSA key");
758 return 0;
759 case KEY_DSA:
760 case KEY_DSA_CERT:
761 if (key->dsa == NULL)
762 return 0;
763 break;
764 case KEY_RSA:
765 case KEY_RSA_CERT:
766 if (key->rsa == NULL)
767 return 0;
768 break;
769 default:
770 return 0;
771 }
772
773 key_to_blob(key, &blob, &len);
774 uu = xmalloc(2*len);
775 n = uuencode(blob, len, uu, 2*len);
776 if (n > 0) {
777 fprintf(f, "%s %s", key_ssh_name(key), uu);
778 success = 1;
779 }
780 xfree(blob);
781 xfree(uu);
782
783 return success;
784 }
785
786 const char *
787 key_type(const Key *k)
788 {
789 switch (k->type) {
790 case KEY_RSA1:
791 return "RSA1";
792 case KEY_RSA:
793 return "RSA";
794 case KEY_DSA:
795 return "DSA";
796 case KEY_RSA_CERT:
797 return "RSA-CERT";
798 case KEY_DSA_CERT:
799 return "DSA-CERT";
800 }
801 return "unknown";
802 }
803
804 const char *
805 key_cert_type(const Key *k)
806 {
807 switch (k->cert->type) {
808 case SSH2_CERT_TYPE_USER:
809 return "user";
810 case SSH2_CERT_TYPE_HOST:
811 return "host";
812 default:
813 return "unknown";
814 }
815 }
816
817 const char *
818 key_ssh_name(const Key *k)
819 {
820 switch (k->type) {
821 case KEY_RSA:
822 return "ssh-rsa";
823 case KEY_DSA:
824 return "ssh-dss";
825 case KEY_RSA_CERT:
826 return "ssh-rsa-cert-v00@openssh.com";
827 case KEY_DSA_CERT:
828 return "ssh-dss-cert-v00@openssh.com";
829 }
830 return "ssh-unknown";
831 }
832
833 u_int
834 key_size(const Key *k)
835 {
836 switch (k->type) {
837 case KEY_RSA1:
838 case KEY_RSA:
839 case KEY_RSA_CERT:
840 return BN_num_bits(k->rsa->n);
841 case KEY_DSA:
842 case KEY_DSA_CERT:
843 return BN_num_bits(k->dsa->p);
844 }
845 return 0;
846 }
847
848 static RSA *
849 rsa_generate_private_key(u_int bits)
850 {
851 RSA *private;
852
853 private = RSA_generate_key(bits, RSA_F4, NULL, NULL);
854 if (private == NULL)
855 fatal("rsa_generate_private_key: key generation failed.");
856 return private;
857 }
858
859 static DSA*
860 dsa_generate_private_key(u_int bits)
861 {
862 DSA *private = DSA_generate_parameters(bits, NULL, 0, NULL, NULL, NULL, NULL);
863
864 if (private == NULL)
865 fatal("dsa_generate_private_key: DSA_generate_parameters failed");
866 if (!DSA_generate_key(private))
867 fatal("dsa_generate_private_key: DSA_generate_key failed.");
868 if (private == NULL)
869 fatal("dsa_generate_private_key: NULL.");
870 return private;
871 }
872
873 Key *
874 key_generate(int type, u_int bits)
875 {
876 Key *k = key_new(KEY_UNSPEC);
877 switch (type) {
878 case KEY_DSA:
879 k->dsa = dsa_generate_private_key(bits);
880 break;
881 case KEY_RSA:
882 case KEY_RSA1:
883 k->rsa = rsa_generate_private_key(bits);
884 break;
885 case KEY_RSA_CERT:
886 case KEY_DSA_CERT:
887 fatal("key_generate: cert keys cannot be generated directly");
888 default:
889 fatal("key_generate: unknown type %d", type);
890 }
891 k->type = type;
892 return k;
893 }
894
895 void
896 key_cert_copy(const Key *from_key, struct Key *to_key)
897 {
898 u_int i;
899 const struct KeyCert *from;
900 struct KeyCert *to;
901
902 if (to_key->cert != NULL) {
903 cert_free(to_key->cert);
904 to_key->cert = NULL;
905 }
906
907 if ((from = from_key->cert) == NULL)
908 return;
909
910 to = to_key->cert = cert_new();
911
912 buffer_append(&to->certblob, buffer_ptr(&from->certblob),
913 buffer_len(&from->certblob));
914
915 buffer_append(&to->constraints, buffer_ptr(&from->constraints),
916 buffer_len(&from->constraints));
917
918 to->type = from->type;
919 to->key_id = from->key_id == NULL ? NULL : xstrdup(from->key_id);
920 to->valid_after = from->valid_after;
921 to->valid_before = from->valid_before;
922 to->signature_key = from->signature_key == NULL ?
923 NULL : key_from_private(from->signature_key);
924
925 to->nprincipals = from->nprincipals;
926 if (to->nprincipals > CERT_MAX_PRINCIPALS)
927 fatal("%s: nprincipals (%u) > CERT_MAX_PRINCIPALS (%u)",
928 __func__, to->nprincipals, CERT_MAX_PRINCIPALS);
929 if (to->nprincipals > 0) {
930 to->principals = xcalloc(from->nprincipals,
931 sizeof(*to->principals));
932 for (i = 0; i < to->nprincipals; i++)
933 to->principals[i] = xstrdup(from->principals[i]);
934 }
935 }
936
937 Key *
938 key_from_private(const Key *k)
939 {
940 Key *n = NULL;
941 switch (k->type) {
942 case KEY_DSA:
943 case KEY_DSA_CERT:
944 n = key_new(k->type);
945 if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) ||
946 (BN_copy(n->dsa->q, k->dsa->q) == NULL) ||
947 (BN_copy(n->dsa->g, k->dsa->g) == NULL) ||
948 (BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL))
949 fatal("key_from_private: BN_copy failed");
950 break;
951 case KEY_RSA:
952 case KEY_RSA1:
953 case KEY_RSA_CERT:
954 n = key_new(k->type);
955 if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) ||
956 (BN_copy(n->rsa->e, k->rsa->e) == NULL))
957 fatal("key_from_private: BN_copy failed");
958 break;
959 default:
960 fatal("key_from_private: unknown type %d", k->type);
961 break;
962 }
963 if (key_is_cert(k))
964 key_cert_copy(k, n);
965 return n;
966 }
967
968 int
969 key_type_from_name(char *name)
970 {
971 if (strcmp(name, "rsa1") == 0) {
972 return KEY_RSA1;
973 } else if (strcmp(name, "rsa") == 0) {
974 return KEY_RSA;
975 } else if (strcmp(name, "dsa") == 0) {
976 return KEY_DSA;
977 } else if (strcmp(name, "ssh-rsa") == 0) {
978 return KEY_RSA;
979 } else if (strcmp(name, "ssh-dss") == 0) {
980 return KEY_DSA;
981 } else if (strcmp(name, "ssh-rsa-cert-v00@openssh.com") == 0) {
982 return KEY_RSA_CERT;
983 } else if (strcmp(name, "ssh-dss-cert-v00@openssh.com") == 0) {
984 return KEY_DSA_CERT;
985 }
986 debug2("key_type_from_name: unknown key type '%s'", name);
987 return KEY_UNSPEC;
988 }
989
990 int
991 key_names_valid2(const char *names)
992 {
993 char *s, *cp, *p;
994
995 if (names == NULL || strcmp(names, "") == 0)
996 return 0;
997 s = cp = xstrdup(names);
998 for ((p = strsep(&cp, ",")); p && *p != '\0';
999 (p = strsep(&cp, ","))) {
1000 switch (key_type_from_name(p)) {
1001 case KEY_RSA1:
1002 case KEY_UNSPEC:
1003 xfree(s);
1004 return 0;
1005 }
1006 }
1007 debug3("key names ok: [%s]", names);
1008 xfree(s);
1009 return 1;
1010 }
1011
1012 static int
1013 cert_parse(Buffer *b, Key *key, const u_char *blob, u_int blen)
1014 {
1015 u_char *principals, *constraints, *sig_key, *sig;
1016 u_int signed_len, plen, clen, sklen, slen, kidlen;
1017 Buffer tmp;
1018 char *principal;
1019 int ret = -1;
1020
1021 buffer_init(&tmp);
1022
1023 /* Copy the entire key blob for verification and later serialisation */
1024 buffer_append(&key->cert->certblob, blob, blen);
1025
1026 principals = constraints = sig_key = sig = NULL;
1027 if (buffer_get_int_ret(&key->cert->type, b) != 0 ||
1028 (key->cert->key_id = buffer_get_string_ret(b, &kidlen)) == NULL ||
1029 (principals = buffer_get_string_ret(b, &plen)) == NULL ||
1030 buffer_get_int64_ret(&key->cert->valid_after, b) != 0 ||
1031 buffer_get_int64_ret(&key->cert->valid_before, b) != 0 ||
1032 (constraints = buffer_get_string_ret(b, &clen)) == NULL ||
1033 /* skip nonce */ buffer_get_string_ptr_ret(b, NULL) == NULL ||
1034 /* skip reserved */ buffer_get_string_ptr_ret(b, NULL) == NULL ||
1035 (sig_key = buffer_get_string_ret(b, &sklen)) == NULL) {
1036 error("%s: parse error", __func__);
1037 goto out;
1038 }
1039
1040 if (kidlen != strlen(key->cert->key_id)) {
1041 error("%s: key ID contains \\0 character", __func__);
1042 goto out;
1043 }
1044
1045 /* Signature is left in the buffer so we can calculate this length */
1046 signed_len = buffer_len(&key->cert->certblob) - buffer_len(b);
1047
1048 if ((sig = buffer_get_string_ret(b, &slen)) == NULL) {
1049 error("%s: parse error", __func__);
1050 goto out;
1051 }
1052
1053 if (key->cert->type != SSH2_CERT_TYPE_USER &&
1054 key->cert->type != SSH2_CERT_TYPE_HOST) {
1055 error("Unknown certificate type %u", key->cert->type);
1056 goto out;
1057 }
1058
1059 buffer_append(&tmp, principals, plen);
1060 while (buffer_len(&tmp) > 0) {
1061 if (key->cert->nprincipals >= CERT_MAX_PRINCIPALS) {
1062 error("%s: Too many principals", __func__);
1063 goto out;
1064 }
1065 if ((principal = buffer_get_string_ret(&tmp, &plen)) == NULL) {
1066 error("%s: Principals data invalid", __func__);
1067 goto out;
1068 }
1069 if (strlen(principal) != plen) {
1070 error("%s: Principal contains \\0 character",
1071 __func__);
1072 goto out;
1073 }
1074 key->cert->principals = xrealloc(key->cert->principals,
1075 key->cert->nprincipals + 1, sizeof(*key->cert->principals));
1076 key->cert->principals[key->cert->nprincipals++] = principal;
1077 }
1078
1079 buffer_clear(&tmp);
1080
1081 buffer_append(&key->cert->constraints, constraints, clen);
1082 buffer_append(&tmp, constraints, clen);
1083 /* validate structure */
1084 while (buffer_len(&tmp) != 0) {
1085 if (buffer_get_string_ptr_ret(&tmp, NULL) == NULL ||
1086 buffer_get_string_ptr_ret(&tmp, NULL) == NULL) {
1087 error("%s: Constraints data invalid", __func__);
1088 goto out;
1089 }
1090 }
1091 buffer_clear(&tmp);
1092
1093 if ((key->cert->signature_key = key_from_blob(sig_key,
1094 sklen)) == NULL) {
1095 error("%s: Signature key invalid", __func__);
1096 goto out;
1097 }
1098 if (key->cert->signature_key->type != KEY_RSA &&
1099 key->cert->signature_key->type != KEY_DSA) {
1100 error("%s: Invalid signature key type %s (%d)", __func__,
1101 key_type(key->cert->signature_key),
1102 key->cert->signature_key->type);
1103 goto out;
1104 }
1105
1106 switch (key_verify(key->cert->signature_key, sig, slen,
1107 buffer_ptr(&key->cert->certblob), signed_len)) {
1108 case 1:
1109 ret = 0;
1110 break; /* Good signature */
1111 case 0:
1112 error("%s: Invalid signature on certificate", __func__);
1113 goto out;
1114 case -1:
1115 error("%s: Certificate signature verification failed",
1116 __func__);
1117 goto out;
1118 }
1119
1120 out:
1121 buffer_free(&tmp);
1122 if (principals != NULL)
1123 xfree(principals);
1124 if (constraints != NULL)
1125 xfree(constraints);
1126 if (sig_key != NULL)
1127 xfree(sig_key);
1128 if (sig != NULL)
1129 xfree(sig);
1130 return ret;
1131 }
1132
1133 Key *
1134 key_from_blob(const u_char *blob, u_int blen)
1135 {
1136 Buffer b;
1137 int rlen, type;
1138 char *ktype = NULL;
1139 Key *key = NULL;
1140
1141 #ifdef DEBUG_PK
1142 dump_base64(stderr, blob, blen);
1143 #endif
1144 buffer_init(&b);
1145 buffer_append(&b, blob, blen);
1146 if ((ktype = buffer_get_string_ret(&b, NULL)) == NULL) {
1147 error("key_from_blob: can't read key type");
1148 goto out;
1149 }
1150
1151 type = key_type_from_name(ktype);
1152
1153 switch (type) {
1154 case KEY_RSA:
1155 case KEY_RSA_CERT:
1156 key = key_new(type);
1157 if (buffer_get_bignum2_ret(&b, key->rsa->e) == -1 ||
1158 buffer_get_bignum2_ret(&b, key->rsa->n) == -1) {
1159 error("key_from_blob: can't read rsa key");
1160 badkey:
1161 key_free(key);
1162 key = NULL;
1163 goto out;
1164 }
1165 #ifdef DEBUG_PK
1166 RSA_print_fp(stderr, key->rsa, 8);
1167 #endif
1168 break;
1169 case KEY_DSA:
1170 case KEY_DSA_CERT:
1171 key = key_new(type);
1172 if (buffer_get_bignum2_ret(&b, key->dsa->p) == -1 ||
1173 buffer_get_bignum2_ret(&b, key->dsa->q) == -1 ||
1174 buffer_get_bignum2_ret(&b, key->dsa->g) == -1 ||
1175 buffer_get_bignum2_ret(&b, key->dsa->pub_key) == -1) {
1176 error("key_from_blob: can't read dsa key");
1177 goto badkey;
1178 }
1179 #ifdef DEBUG_PK
1180 DSA_print_fp(stderr, key->dsa, 8);
1181 #endif
1182 break;
1183 case KEY_UNSPEC:
1184 key = key_new(type);
1185 break;
1186 default:
1187 error("key_from_blob: cannot handle type %s", ktype);
1188 goto out;
1189 }
1190 if (key_is_cert(key) && cert_parse(&b, key, blob, blen) == -1) {
1191 error("key_from_blob: can't parse cert data");
1192 goto badkey;
1193 }
1194 rlen = buffer_len(&b);
1195 if (key != NULL && rlen != 0)
1196 error("key_from_blob: remaining bytes in key blob %d", rlen);
1197 out:
1198 if (ktype != NULL)
1199 xfree(ktype);
1200 buffer_free(&b);
1201 return key;
1202 }
1203
1204 int
1205 key_to_blob(const Key *key, u_char **blobp, u_int *lenp)
1206 {
1207 Buffer b;
1208 int len;
1209
1210 if (key == NULL) {
1211 error("key_to_blob: key == NULL");
1212 return 0;
1213 }
1214 buffer_init(&b);
1215 switch (key->type) {
1216 case KEY_DSA_CERT:
1217 case KEY_RSA_CERT:
1218 /* Use the existing blob */
1219 buffer_append(&b, buffer_ptr(&key->cert->certblob),
1220 buffer_len(&key->cert->certblob));
1221 break;
1222 case KEY_DSA:
1223 buffer_put_cstring(&b, key_ssh_name(key));
1224 buffer_put_bignum2(&b, key->dsa->p);
1225 buffer_put_bignum2(&b, key->dsa->q);
1226 buffer_put_bignum2(&b, key->dsa->g);
1227 buffer_put_bignum2(&b, key->dsa->pub_key);
1228 break;
1229 case KEY_RSA:
1230 buffer_put_cstring(&b, key_ssh_name(key));
1231 buffer_put_bignum2(&b, key->rsa->e);
1232 buffer_put_bignum2(&b, key->rsa->n);
1233 break;
1234 default:
1235 error("key_to_blob: unsupported key type %d", key->type);
1236 buffer_free(&b);
1237 return 0;
1238 }
1239 len = buffer_len(&b);
1240 if (lenp != NULL)
1241 *lenp = len;
1242 if (blobp != NULL) {
1243 *blobp = xmalloc(len);
1244 memcpy(*blobp, buffer_ptr(&b), len);
1245 }
1246 memset(buffer_ptr(&b), 0, len);
1247 buffer_free(&b);
1248 return len;
1249 }
1250
1251 int
1252 key_sign(
1253 const Key *key,
1254 u_char **sigp, u_int *lenp,
1255 const u_char *data, u_int datalen)
1256 {
1257 switch (key->type) {
1258 case KEY_DSA_CERT:
1259 case KEY_DSA:
1260 return ssh_dss_sign(key, sigp, lenp, data, datalen);
1261 case KEY_RSA_CERT:
1262 case KEY_RSA:
1263 return ssh_rsa_sign(key, sigp, lenp, data, datalen);
1264 default:
1265 error("key_sign: invalid key type %d", key->type);
1266 return -1;
1267 }
1268 }
1269
1270 /*
1271 * key_verify returns 1 for a correct signature, 0 for an incorrect signature
1272 * and -1 on error.
1273 */
1274 int
1275 key_verify(
1276 const Key *key,
1277 const u_char *signature, u_int signaturelen,
1278 const u_char *data, u_int datalen)
1279 {
1280 if (signaturelen == 0)
1281 return -1;
1282
1283 switch (key->type) {
1284 case KEY_DSA_CERT:
1285 case KEY_DSA:
1286 return ssh_dss_verify(key, signature, signaturelen, data, datalen);
1287 case KEY_RSA_CERT:
1288 case KEY_RSA:
1289 return ssh_rsa_verify(key, signature, signaturelen, data, datalen);
1290 default:
1291 error("key_verify: invalid key type %d", key->type);
1292 return -1;
1293 }
1294 }
1295
1296 /* Converts a private to a public key */
1297 Key *
1298 key_demote(const Key *k)
1299 {
1300 Key *pk;
1301
1302 pk = xcalloc(1, sizeof(*pk));
1303 pk->type = k->type;
1304 pk->flags = k->flags;
1305 pk->dsa = NULL;
1306 pk->rsa = NULL;
1307
1308 switch (k->type) {
1309 case KEY_RSA_CERT:
1310 key_cert_copy(k, pk);
1311 /* FALLTHROUGH */
1312 case KEY_RSA1:
1313 case KEY_RSA:
1314 if ((pk->rsa = RSA_new()) == NULL)
1315 fatal("key_demote: RSA_new failed");
1316 if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL)
1317 fatal("key_demote: BN_dup failed");
1318 if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL)
1319 fatal("key_demote: BN_dup failed");
1320 break;
1321 case KEY_DSA_CERT:
1322 key_cert_copy(k, pk);
1323 /* FALLTHROUGH */
1324 case KEY_DSA:
1325 if ((pk->dsa = DSA_new()) == NULL)
1326 fatal("key_demote: DSA_new failed");
1327 if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL)
1328 fatal("key_demote: BN_dup failed");
1329 if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL)
1330 fatal("key_demote: BN_dup failed");
1331 if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL)
1332 fatal("key_demote: BN_dup failed");
1333 if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL)
1334 fatal("key_demote: BN_dup failed");
1335 break;
1336 default:
1337 fatal("key_free: bad key type %d", k->type);
1338 break;
1339 }
1340
1341 return (pk);
1342 }
1343
1344 int
1345 key_is_cert(const Key *k)
1346 {
1347 return k != NULL &&
1348 (k->type == KEY_RSA_CERT || k->type == KEY_DSA_CERT);
1349 }
1350
1351 /* Return the cert-less equivalent to a certified key type */
1352 int
1353 key_type_plain(int type)
1354 {
1355 switch (type) {
1356 case KEY_RSA_CERT:
1357 return KEY_RSA;
1358 case KEY_DSA_CERT:
1359 return KEY_DSA;
1360 default:
1361 return type;
1362 }
1363 }
1364
1365 /* Convert a KEY_RSA or KEY_DSA to their _CERT equivalent */
1366 int
1367 key_to_certified(Key *k)
1368 {
1369 switch (k->type) {
1370 case KEY_RSA:
1371 k->cert = cert_new();
1372 k->type = KEY_RSA_CERT;
1373 return 0;
1374 case KEY_DSA:
1375 k->cert = cert_new();
1376 k->type = KEY_DSA_CERT;
1377 return 0;
1378 default:
1379 error("%s: key has incorrect type %s", __func__, key_type(k));
1380 return -1;
1381 }
1382 }
1383
1384 /* Convert a KEY_RSA_CERT or KEY_DSA_CERT to their raw key equivalent */
1385 int
1386 key_drop_cert(Key *k)
1387 {
1388 switch (k->type) {
1389 case KEY_RSA_CERT:
1390 cert_free(k->cert);
1391 k->type = KEY_RSA;
1392 return 0;
1393 case KEY_DSA_CERT:
1394 cert_free(k->cert);
1395 k->type = KEY_DSA;
1396 return 0;
1397 default:
1398 error("%s: key has incorrect type %s", __func__, key_type(k));
1399 return -1;
1400 }
1401 }
1402
1403 /* Sign a KEY_RSA_CERT or KEY_DSA_CERT, (re-)generating the signed certblob */
1404 int
1405 key_certify(Key *k, Key *ca)
1406 {
1407 Buffer principals;
1408 u_char *ca_blob, *sig_blob, nonce[32];
1409 u_int i, ca_len, sig_len;
1410
1411 if (k->cert == NULL) {
1412 error("%s: key lacks cert info", __func__);
1413 return -1;
1414 }
1415
1416 if (!key_is_cert(k)) {
1417 error("%s: certificate has unknown type %d", __func__,
1418 k->cert->type);
1419 return -1;
1420 }
1421
1422 if (ca->type != KEY_RSA && ca->type != KEY_DSA) {
1423 error("%s: CA key has unsupported type %s", __func__,
1424 key_type(ca));
1425 return -1;
1426 }
1427
1428 key_to_blob(ca, &ca_blob, &ca_len);
1429
1430 buffer_clear(&k->cert->certblob);
1431 buffer_put_cstring(&k->cert->certblob, key_ssh_name(k));
1432
1433 switch (k->type) {
1434 case KEY_DSA_CERT:
1435 buffer_put_bignum2(&k->cert->certblob, k->dsa->p);
1436 buffer_put_bignum2(&k->cert->certblob, k->dsa->q);
1437 buffer_put_bignum2(&k->cert->certblob, k->dsa->g);
1438 buffer_put_bignum2(&k->cert->certblob, k->dsa->pub_key);
1439 break;
1440 case KEY_RSA_CERT:
1441 buffer_put_bignum2(&k->cert->certblob, k->rsa->e);
1442 buffer_put_bignum2(&k->cert->certblob, k->rsa->n);
1443 break;
1444 default:
1445 error("%s: key has incorrect type %s", __func__, key_type(k));
1446 buffer_clear(&k->cert->certblob);
1447 xfree(ca_blob);
1448 return -1;
1449 }
1450
1451 buffer_put_int(&k->cert->certblob, k->cert->type);
1452 buffer_put_cstring(&k->cert->certblob, k->cert->key_id);
1453
1454 buffer_init(&principals);
1455 for (i = 0; i < k->cert->nprincipals; i++)
1456 buffer_put_cstring(&principals, k->cert->principals[i]);
1457 buffer_put_string(&k->cert->certblob, buffer_ptr(&principals),
1458 buffer_len(&principals));
1459 buffer_free(&principals);
1460
1461 buffer_put_int64(&k->cert->certblob, k->cert->valid_after);
1462 buffer_put_int64(&k->cert->certblob, k->cert->valid_before);
1463 buffer_put_string(&k->cert->certblob,
1464 buffer_ptr(&k->cert->constraints),
1465 buffer_len(&k->cert->constraints));
1466
1467 arc4random_buf(&nonce, sizeof(nonce));
1468 buffer_put_string(&k->cert->certblob, nonce, sizeof(nonce));
1469 buffer_put_string(&k->cert->certblob, NULL, 0); /* reserved */
1470 buffer_put_string(&k->cert->certblob, ca_blob, ca_len);
1471 xfree(ca_blob);
1472
1473 /* Sign the whole mess */
1474 if (key_sign(ca, &sig_blob, &sig_len, buffer_ptr(&k->cert->certblob),
1475 buffer_len(&k->cert->certblob)) != 0) {
1476 error("%s: signature operation failed", __func__);
1477 buffer_clear(&k->cert->certblob);
1478 return -1;
1479 }
1480 /* Append signature and we are done */
1481 buffer_put_string(&k->cert->certblob, sig_blob, sig_len);
1482 xfree(sig_blob);
1483
1484 return 0;
1485 }
1486
1487 int
1488 key_cert_check_authority(const Key *k, int want_host, int require_principal,
1489 const char *name, const char **reason)
1490 {
1491 u_int i, principal_matches;
1492 time_t now = time(NULL);
1493
1494 if (want_host) {
1495 if (k->cert->type != SSH2_CERT_TYPE_HOST) {
1496 *reason = "Certificate invalid: not a host certificate";
1497 return -1;
1498 }
1499 } else {
1500 if (k->cert->type != SSH2_CERT_TYPE_USER) {
1501 *reason = "Certificate invalid: not a user certificate";
1502 return -1;
1503 }
1504 }
1505 if (now < 0) {
1506 error("%s: system clock lies before epoch", __func__);
1507 *reason = "Certificate invalid: not yet valid";
1508 return -1;
1509 }
1510 if ((u_int64_t)now < k->cert->valid_after) {
1511 *reason = "Certificate invalid: not yet valid";
1512 return -1;
1513 }
1514 if ((u_int64_t)now >= k->cert->valid_before) {
1515 *reason = "Certificate invalid: expired";
1516 return -1;
1517 }
1518 if (k->cert->nprincipals == 0) {
1519 if (require_principal) {
1520 *reason = "Certificate lacks principal list";
1521 return -1;
1522 }
1523 } else {
1524 principal_matches = 0;
1525 for (i = 0; i < k->cert->nprincipals; i++) {
1526 if (strcmp(name, k->cert->principals[i]) == 0) {
1527 principal_matches = 1;
1528 break;
1529 }
1530 }
1531 if (!principal_matches) {
1532 *reason = "Certificate invalid: name is not a listed "
1533 "principal";
1534 return -1;
1535 }
1536 }
1537 return 0;
1538 }
A clone of openssh git repository