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1 | /* $OpenBSD: key.c,v 1.82 2010/01/13 01:10:56 dtucker 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 | ||
56 | Key * | |
57 | key_new(int type) | |
58 | { | |
59 | Key *k; | |
60 | RSA *rsa; | |
61 | DSA *dsa; | |
62 | k = xcalloc(1, sizeof(*k)); | |
63 | k->type = type; | |
64 | k->dsa = NULL; | |
65 | k->rsa = NULL; | |
66 | switch (k->type) { | |
67 | case KEY_RSA1: | |
68 | case KEY_RSA: | |
69 | if ((rsa = RSA_new()) == NULL) | |
70 | fatal("key_new: RSA_new failed"); | |
71 | if ((rsa->n = BN_new()) == NULL) | |
72 | fatal("key_new: BN_new failed"); | |
73 | if ((rsa->e = BN_new()) == NULL) | |
74 | fatal("key_new: BN_new failed"); | |
75 | k->rsa = rsa; | |
76 | break; | |
77 | case KEY_DSA: | |
78 | if ((dsa = DSA_new()) == NULL) | |
79 | fatal("key_new: DSA_new failed"); | |
80 | if ((dsa->p = BN_new()) == NULL) | |
81 | fatal("key_new: BN_new failed"); | |
82 | if ((dsa->q = BN_new()) == NULL) | |
83 | fatal("key_new: BN_new failed"); | |
84 | if ((dsa->g = BN_new()) == NULL) | |
85 | fatal("key_new: BN_new failed"); | |
86 | if ((dsa->pub_key = BN_new()) == NULL) | |
87 | fatal("key_new: BN_new failed"); | |
88 | k->dsa = dsa; | |
89 | break; | |
90 | case KEY_UNSPEC: | |
91 | break; | |
92 | default: | |
93 | fatal("key_new: bad key type %d", k->type); | |
94 | break; | |
95 | } | |
96 | return k; | |
97 | } | |
98 | ||
99 | Key * | |
100 | key_new_private(int type) | |
101 | { | |
102 | Key *k = key_new(type); | |
103 | switch (k->type) { | |
104 | case KEY_RSA1: | |
105 | case KEY_RSA: | |
106 | if ((k->rsa->d = BN_new()) == NULL) | |
107 | fatal("key_new_private: BN_new failed"); | |
108 | if ((k->rsa->iqmp = BN_new()) == NULL) | |
109 | fatal("key_new_private: BN_new failed"); | |
110 | if ((k->rsa->q = BN_new()) == NULL) | |
111 | fatal("key_new_private: BN_new failed"); | |
112 | if ((k->rsa->p = BN_new()) == NULL) | |
113 | fatal("key_new_private: BN_new failed"); | |
114 | if ((k->rsa->dmq1 = BN_new()) == NULL) | |
115 | fatal("key_new_private: BN_new failed"); | |
116 | if ((k->rsa->dmp1 = BN_new()) == NULL) | |
117 | fatal("key_new_private: BN_new failed"); | |
118 | break; | |
119 | case KEY_DSA: | |
120 | if ((k->dsa->priv_key = BN_new()) == NULL) | |
121 | fatal("key_new_private: BN_new failed"); | |
122 | break; | |
123 | case KEY_UNSPEC: | |
124 | break; | |
125 | default: | |
126 | break; | |
127 | } | |
128 | return k; | |
129 | } | |
130 | ||
131 | void | |
132 | key_free(Key *k) | |
133 | { | |
134 | if (k == NULL) | |
135 | fatal("key_free: key is NULL"); | |
136 | switch (k->type) { | |
137 | case KEY_RSA1: | |
138 | case KEY_RSA: | |
139 | if (k->rsa != NULL) | |
140 | RSA_free(k->rsa); | |
141 | k->rsa = NULL; | |
142 | break; | |
143 | case KEY_DSA: | |
144 | if (k->dsa != NULL) | |
145 | DSA_free(k->dsa); | |
146 | k->dsa = NULL; | |
147 | break; | |
148 | case KEY_UNSPEC: | |
149 | break; | |
150 | default: | |
151 | fatal("key_free: bad key type %d", k->type); | |
152 | break; | |
153 | } | |
154 | xfree(k); | |
155 | } | |
156 | ||
157 | int | |
158 | key_equal(const Key *a, const Key *b) | |
159 | { | |
160 | if (a == NULL || b == NULL || a->type != b->type) | |
161 | return 0; | |
162 | switch (a->type) { | |
163 | case KEY_RSA1: | |
164 | case KEY_RSA: | |
165 | return a->rsa != NULL && b->rsa != NULL && | |
166 | BN_cmp(a->rsa->e, b->rsa->e) == 0 && | |
167 | BN_cmp(a->rsa->n, b->rsa->n) == 0; | |
168 | case KEY_DSA: | |
169 | return a->dsa != NULL && b->dsa != NULL && | |
170 | BN_cmp(a->dsa->p, b->dsa->p) == 0 && | |
171 | BN_cmp(a->dsa->q, b->dsa->q) == 0 && | |
172 | BN_cmp(a->dsa->g, b->dsa->g) == 0 && | |
173 | BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0; | |
174 | default: | |
175 | fatal("key_equal: bad key type %d", a->type); | |
176 | } | |
177 | /* NOTREACHED */ | |
178 | } | |
179 | ||
180 | u_char* | |
181 | key_fingerprint_raw(const Key *k, enum fp_type dgst_type, | |
182 | u_int *dgst_raw_length) | |
183 | { | |
184 | const EVP_MD *md = NULL; | |
185 | EVP_MD_CTX ctx; | |
186 | u_char *blob = NULL; | |
187 | u_char *retval = NULL; | |
188 | u_int len = 0; | |
189 | int nlen, elen; | |
190 | ||
191 | *dgst_raw_length = 0; | |
192 | ||
193 | switch (dgst_type) { | |
194 | case SSH_FP_MD5: | |
195 | md = EVP_md5(); | |
196 | break; | |
197 | case SSH_FP_SHA1: | |
198 | md = EVP_sha1(); | |
199 | break; | |
200 | default: | |
201 | fatal("key_fingerprint_raw: bad digest type %d", | |
202 | dgst_type); | |
203 | } | |
204 | switch (k->type) { | |
205 | case KEY_RSA1: | |
206 | nlen = BN_num_bytes(k->rsa->n); | |
207 | elen = BN_num_bytes(k->rsa->e); | |
208 | len = nlen + elen; | |
209 | blob = xmalloc(len); | |
210 | BN_bn2bin(k->rsa->n, blob); | |
211 | BN_bn2bin(k->rsa->e, blob + nlen); | |
212 | break; | |
213 | case KEY_DSA: | |
214 | case KEY_RSA: | |
215 | key_to_blob(k, &blob, &len); | |
216 | break; | |
217 | case KEY_UNSPEC: | |
218 | return retval; | |
219 | default: | |
220 | fatal("key_fingerprint_raw: bad key type %d", k->type); | |
221 | break; | |
222 | } | |
223 | if (blob != NULL) { | |
224 | retval = xmalloc(EVP_MAX_MD_SIZE); | |
225 | EVP_DigestInit(&ctx, md); | |
226 | EVP_DigestUpdate(&ctx, blob, len); | |
227 | EVP_DigestFinal(&ctx, retval, dgst_raw_length); | |
228 | memset(blob, 0, len); | |
229 | xfree(blob); | |
230 | } else { | |
231 | fatal("key_fingerprint_raw: blob is null"); | |
232 | } | |
233 | return retval; | |
234 | } | |
235 | ||
236 | static char * | |
237 | key_fingerprint_hex(u_char *dgst_raw, u_int dgst_raw_len) | |
238 | { | |
239 | char *retval; | |
240 | u_int i; | |
241 | ||
242 | retval = xcalloc(1, dgst_raw_len * 3 + 1); | |
243 | for (i = 0; i < dgst_raw_len; i++) { | |
244 | char hex[4]; | |
245 | snprintf(hex, sizeof(hex), "%02x:", dgst_raw[i]); | |
246 | strlcat(retval, hex, dgst_raw_len * 3 + 1); | |
247 | } | |
248 | ||
249 | /* Remove the trailing ':' character */ | |
250 | retval[(dgst_raw_len * 3) - 1] = '\0'; | |
251 | return retval; | |
252 | } | |
253 | ||
254 | static char * | |
255 | key_fingerprint_bubblebabble(u_char *dgst_raw, u_int dgst_raw_len) | |
256 | { | |
257 | char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' }; | |
258 | char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm', | |
259 | 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' }; | |
260 | u_int i, j = 0, rounds, seed = 1; | |
261 | char *retval; | |
262 | ||
263 | rounds = (dgst_raw_len / 2) + 1; | |
264 | retval = xcalloc((rounds * 6), sizeof(char)); | |
265 | retval[j++] = 'x'; | |
266 | for (i = 0; i < rounds; i++) { | |
267 | u_int idx0, idx1, idx2, idx3, idx4; | |
268 | if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) { | |
269 | idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) + | |
270 | seed) % 6; | |
271 | idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15; | |
272 | idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) + | |
273 | (seed / 6)) % 6; | |
274 | retval[j++] = vowels[idx0]; | |
275 | retval[j++] = consonants[idx1]; | |
276 | retval[j++] = vowels[idx2]; | |
277 | if ((i + 1) < rounds) { | |
278 | idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15; | |
279 | idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15; | |
280 | retval[j++] = consonants[idx3]; | |
281 | retval[j++] = '-'; | |
282 | retval[j++] = consonants[idx4]; | |
283 | seed = ((seed * 5) + | |
284 | ((((u_int)(dgst_raw[2 * i])) * 7) + | |
285 | ((u_int)(dgst_raw[(2 * i) + 1])))) % 36; | |
286 | } | |
287 | } else { | |
288 | idx0 = seed % 6; | |
289 | idx1 = 16; | |
290 | idx2 = seed / 6; | |
291 | retval[j++] = vowels[idx0]; | |
292 | retval[j++] = consonants[idx1]; | |
293 | retval[j++] = vowels[idx2]; | |
294 | } | |
295 | } | |
296 | retval[j++] = 'x'; | |
297 | retval[j++] = '\0'; | |
298 | return retval; | |
299 | } | |
300 | ||
301 | /* | |
302 | * Draw an ASCII-Art representing the fingerprint so human brain can | |
303 | * profit from its built-in pattern recognition ability. | |
304 | * This technique is called "random art" and can be found in some | |
305 | * scientific publications like this original paper: | |
306 | * | |
307 | * "Hash Visualization: a New Technique to improve Real-World Security", | |
308 | * Perrig A. and Song D., 1999, International Workshop on Cryptographic | |
309 | * Techniques and E-Commerce (CrypTEC '99) | |
310 | * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf | |
311 | * | |
312 | * The subject came up in a talk by Dan Kaminsky, too. | |
313 | * | |
314 | * If you see the picture is different, the key is different. | |
315 | * If the picture looks the same, you still know nothing. | |
316 | * | |
317 | * The algorithm used here is a worm crawling over a discrete plane, | |
318 | * leaving a trace (augmenting the field) everywhere it goes. | |
319 | * Movement is taken from dgst_raw 2bit-wise. Bumping into walls | |
320 | * makes the respective movement vector be ignored for this turn. | |
321 | * Graphs are not unambiguous, because circles in graphs can be | |
322 | * walked in either direction. | |
323 | */ | |
324 | ||
325 | /* | |
326 | * Field sizes for the random art. Have to be odd, so the starting point | |
327 | * can be in the exact middle of the picture, and FLDBASE should be >=8 . | |
328 | * Else pictures would be too dense, and drawing the frame would | |
329 | * fail, too, because the key type would not fit in anymore. | |
330 | */ | |
331 | #define FLDBASE 8 | |
332 | #define FLDSIZE_Y (FLDBASE + 1) | |
333 | #define FLDSIZE_X (FLDBASE * 2 + 1) | |
334 | static char * | |
335 | key_fingerprint_randomart(u_char *dgst_raw, u_int dgst_raw_len, const Key *k) | |
336 | { | |
337 | /* | |
338 | * Chars to be used after each other every time the worm | |
339 | * intersects with itself. Matter of taste. | |
340 | */ | |
341 | char *augmentation_string = " .o+=*BOX@%&#/^SE"; | |
342 | char *retval, *p; | |
343 | u_char field[FLDSIZE_X][FLDSIZE_Y]; | |
344 | u_int i, b; | |
345 | int x, y; | |
346 | size_t len = strlen(augmentation_string) - 1; | |
347 | ||
348 | retval = xcalloc(1, (FLDSIZE_X + 3) * (FLDSIZE_Y + 2)); | |
349 | ||
350 | /* initialize field */ | |
351 | memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char)); | |
352 | x = FLDSIZE_X / 2; | |
353 | y = FLDSIZE_Y / 2; | |
354 | ||
355 | /* process raw key */ | |
356 | for (i = 0; i < dgst_raw_len; i++) { | |
357 | int input; | |
358 | /* each byte conveys four 2-bit move commands */ | |
359 | input = dgst_raw[i]; | |
360 | for (b = 0; b < 4; b++) { | |
361 | /* evaluate 2 bit, rest is shifted later */ | |
362 | x += (input & 0x1) ? 1 : -1; | |
363 | y += (input & 0x2) ? 1 : -1; | |
364 | ||
365 | /* assure we are still in bounds */ | |
366 | x = MAX(x, 0); | |
367 | y = MAX(y, 0); | |
368 | x = MIN(x, FLDSIZE_X - 1); | |
369 | y = MIN(y, FLDSIZE_Y - 1); | |
370 | ||
371 | /* augment the field */ | |
372 | if (field[x][y] < len - 2) | |
373 | field[x][y]++; | |
374 | input = input >> 2; | |
375 | } | |
376 | } | |
377 | ||
378 | /* mark starting point and end point*/ | |
379 | field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1; | |
380 | field[x][y] = len; | |
381 | ||
382 | /* fill in retval */ | |
383 | snprintf(retval, FLDSIZE_X, "+--[%4s %4u]", key_type(k), key_size(k)); | |
384 | p = strchr(retval, '\0'); | |
385 | ||
386 | /* output upper border */ | |
387 | for (i = p - retval - 1; i < FLDSIZE_X; i++) | |
388 | *p++ = '-'; | |
389 | *p++ = '+'; | |
390 | *p++ = '\n'; | |
391 | ||
392 | /* output content */ | |
393 | for (y = 0; y < FLDSIZE_Y; y++) { | |
394 | *p++ = '|'; | |
395 | for (x = 0; x < FLDSIZE_X; x++) | |
396 | *p++ = augmentation_string[MIN(field[x][y], len)]; | |
397 | *p++ = '|'; | |
398 | *p++ = '\n'; | |
399 | } | |
400 | ||
401 | /* output lower border */ | |
402 | *p++ = '+'; | |
403 | for (i = 0; i < FLDSIZE_X; i++) | |
404 | *p++ = '-'; | |
405 | *p++ = '+'; | |
406 | ||
407 | return retval; | |
408 | } | |
409 | ||
410 | char * | |
411 | key_fingerprint(const Key *k, enum fp_type dgst_type, enum fp_rep dgst_rep) | |
412 | { | |
413 | char *retval = NULL; | |
414 | u_char *dgst_raw; | |
415 | u_int dgst_raw_len; | |
416 | ||
417 | dgst_raw = key_fingerprint_raw(k, dgst_type, &dgst_raw_len); | |
418 | if (!dgst_raw) | |
419 | fatal("key_fingerprint: null from key_fingerprint_raw()"); | |
420 | switch (dgst_rep) { | |
421 | case SSH_FP_HEX: | |
422 | retval = key_fingerprint_hex(dgst_raw, dgst_raw_len); | |
423 | break; | |
424 | case SSH_FP_BUBBLEBABBLE: | |
425 | retval = key_fingerprint_bubblebabble(dgst_raw, dgst_raw_len); | |
426 | break; | |
427 | case SSH_FP_RANDOMART: | |
428 | retval = key_fingerprint_randomart(dgst_raw, dgst_raw_len, k); | |
429 | break; | |
430 | default: | |
431 | fatal("key_fingerprint: bad digest representation %d", | |
432 | dgst_rep); | |
433 | break; | |
434 | } | |
435 | memset(dgst_raw, 0, dgst_raw_len); | |
436 | xfree(dgst_raw); | |
437 | return retval; | |
438 | } | |
439 | ||
440 | /* | |
441 | * Reads a multiple-precision integer in decimal from the buffer, and advances | |
442 | * the pointer. The integer must already be initialized. This function is | |
443 | * permitted to modify the buffer. This leaves *cpp to point just beyond the | |
444 | * last processed (and maybe modified) character. Note that this may modify | |
445 | * the buffer containing the number. | |
446 | */ | |
447 | static int | |
448 | read_bignum(char **cpp, BIGNUM * value) | |
449 | { | |
450 | char *cp = *cpp; | |
451 | int old; | |
452 | ||
453 | /* Skip any leading whitespace. */ | |
454 | for (; *cp == ' ' || *cp == '\t'; cp++) | |
455 | ; | |
456 | ||
457 | /* Check that it begins with a decimal digit. */ | |
458 | if (*cp < '0' || *cp > '9') | |
459 | return 0; | |
460 | ||
461 | /* Save starting position. */ | |
462 | *cpp = cp; | |
463 | ||
464 | /* Move forward until all decimal digits skipped. */ | |
465 | for (; *cp >= '0' && *cp <= '9'; cp++) | |
466 | ; | |
467 | ||
468 | /* Save the old terminating character, and replace it by \0. */ | |
469 | old = *cp; | |
470 | *cp = 0; | |
471 | ||
472 | /* Parse the number. */ | |
473 | if (BN_dec2bn(&value, *cpp) == 0) | |
474 | return 0; | |
475 | ||
476 | /* Restore old terminating character. */ | |
477 | *cp = old; | |
478 | ||
479 | /* Move beyond the number and return success. */ | |
480 | *cpp = cp; | |
481 | return 1; | |
482 | } | |
483 | ||
484 | static int | |
485 | write_bignum(FILE *f, BIGNUM *num) | |
486 | { | |
487 | char *buf = BN_bn2dec(num); | |
488 | if (buf == NULL) { | |
489 | error("write_bignum: BN_bn2dec() failed"); | |
490 | return 0; | |
491 | } | |
492 | fprintf(f, " %s", buf); | |
493 | OPENSSL_free(buf); | |
494 | return 1; | |
495 | } | |
496 | ||
497 | /* returns 1 ok, -1 error */ | |
498 | int | |
499 | key_read(Key *ret, char **cpp) | |
500 | { | |
501 | Key *k; | |
502 | int success = -1; | |
503 | char *cp, *space; | |
504 | int len, n, type; | |
505 | u_int bits; | |
506 | u_char *blob; | |
507 | ||
508 | cp = *cpp; | |
509 | ||
510 | switch (ret->type) { | |
511 | case KEY_RSA1: | |
512 | /* Get number of bits. */ | |
513 | if (*cp < '0' || *cp > '9') | |
514 | return -1; /* Bad bit count... */ | |
515 | for (bits = 0; *cp >= '0' && *cp <= '9'; cp++) | |
516 | bits = 10 * bits + *cp - '0'; | |
517 | if (bits == 0) | |
518 | return -1; | |
519 | *cpp = cp; | |
520 | /* Get public exponent, public modulus. */ | |
521 | if (!read_bignum(cpp, ret->rsa->e)) | |
522 | return -1; | |
523 | if (!read_bignum(cpp, ret->rsa->n)) | |
524 | return -1; | |
525 | /* validate the claimed number of bits */ | |
526 | if ((u_int)BN_num_bits(ret->rsa->n) != bits) { | |
527 | verbose("key_read: claimed key size %d does not match " | |
528 | "actual %d", bits, BN_num_bits(ret->rsa->n)); | |
529 | return -1; | |
530 | } | |
531 | success = 1; | |
532 | break; | |
533 | case KEY_UNSPEC: | |
534 | case KEY_RSA: | |
535 | case KEY_DSA: | |
536 | space = strchr(cp, ' '); | |
537 | if (space == NULL) { | |
538 | debug3("key_read: missing whitespace"); | |
539 | return -1; | |
540 | } | |
541 | *space = '\0'; | |
542 | type = key_type_from_name(cp); | |
543 | *space = ' '; | |
544 | if (type == KEY_UNSPEC) { | |
545 | debug3("key_read: missing keytype"); | |
546 | return -1; | |
547 | } | |
548 | cp = space+1; | |
549 | if (*cp == '\0') { | |
550 | debug3("key_read: short string"); | |
551 | return -1; | |
552 | } | |
553 | if (ret->type == KEY_UNSPEC) { | |
554 | ret->type = type; | |
555 | } else if (ret->type != type) { | |
556 | /* is a key, but different type */ | |
557 | debug3("key_read: type mismatch"); | |
558 | return -1; | |
559 | } | |
560 | len = 2*strlen(cp); | |
561 | blob = xmalloc(len); | |
562 | n = uudecode(cp, blob, len); | |
563 | if (n < 0) { | |
564 | error("key_read: uudecode %s failed", cp); | |
565 | xfree(blob); | |
566 | return -1; | |
567 | } | |
568 | k = key_from_blob(blob, (u_int)n); | |
569 | xfree(blob); | |
570 | if (k == NULL) { | |
571 | error("key_read: key_from_blob %s failed", cp); | |
572 | return -1; | |
573 | } | |
574 | if (k->type != type) { | |
575 | error("key_read: type mismatch: encoding error"); | |
576 | key_free(k); | |
577 | return -1; | |
578 | } | |
579 | /*XXXX*/ | |
580 | if (ret->type == KEY_RSA) { | |
581 | if (ret->rsa != NULL) | |
582 | RSA_free(ret->rsa); | |
583 | ret->rsa = k->rsa; | |
584 | k->rsa = NULL; | |
585 | success = 1; | |
586 | #ifdef DEBUG_PK | |
587 | RSA_print_fp(stderr, ret->rsa, 8); | |
588 | #endif | |
589 | } else { | |
590 | if (ret->dsa != NULL) | |
591 | DSA_free(ret->dsa); | |
592 | ret->dsa = k->dsa; | |
593 | k->dsa = NULL; | |
594 | success = 1; | |
595 | #ifdef DEBUG_PK | |
596 | DSA_print_fp(stderr, ret->dsa, 8); | |
597 | #endif | |
598 | } | |
599 | /*XXXX*/ | |
600 | key_free(k); | |
601 | if (success != 1) | |
602 | break; | |
603 | /* advance cp: skip whitespace and data */ | |
604 | while (*cp == ' ' || *cp == '\t') | |
605 | cp++; | |
606 | while (*cp != '\0' && *cp != ' ' && *cp != '\t') | |
607 | cp++; | |
608 | *cpp = cp; | |
609 | break; | |
610 | default: | |
611 | fatal("key_read: bad key type: %d", ret->type); | |
612 | break; | |
613 | } | |
614 | return success; | |
615 | } | |
616 | ||
617 | int | |
618 | key_write(const Key *key, FILE *f) | |
619 | { | |
620 | int n, success = 0; | |
621 | u_int len, bits = 0; | |
622 | u_char *blob; | |
623 | char *uu; | |
624 | ||
625 | if (key->type == KEY_RSA1 && key->rsa != NULL) { | |
626 | /* size of modulus 'n' */ | |
627 | bits = BN_num_bits(key->rsa->n); | |
628 | fprintf(f, "%u", bits); | |
629 | if (write_bignum(f, key->rsa->e) && | |
630 | write_bignum(f, key->rsa->n)) { | |
631 | success = 1; | |
632 | } else { | |
633 | error("key_write: failed for RSA key"); | |
634 | } | |
635 | } else if ((key->type == KEY_DSA && key->dsa != NULL) || | |
636 | (key->type == KEY_RSA && key->rsa != NULL)) { | |
637 | key_to_blob(key, &blob, &len); | |
638 | uu = xmalloc(2*len); | |
639 | n = uuencode(blob, len, uu, 2*len); | |
640 | if (n > 0) { | |
641 | fprintf(f, "%s %s", key_ssh_name(key), uu); | |
642 | success = 1; | |
643 | } | |
644 | xfree(blob); | |
645 | xfree(uu); | |
646 | } | |
647 | return success; | |
648 | } | |
649 | ||
650 | const char * | |
651 | key_type(const Key *k) | |
652 | { | |
653 | switch (k->type) { | |
654 | case KEY_RSA1: | |
655 | return "RSA1"; | |
656 | case KEY_RSA: | |
657 | return "RSA"; | |
658 | case KEY_DSA: | |
659 | return "DSA"; | |
660 | } | |
661 | return "unknown"; | |
662 | } | |
663 | ||
664 | const char * | |
665 | key_ssh_name(const Key *k) | |
666 | { | |
667 | switch (k->type) { | |
668 | case KEY_RSA: | |
669 | return "ssh-rsa"; | |
670 | case KEY_DSA: | |
671 | return "ssh-dss"; | |
672 | } | |
673 | return "ssh-unknown"; | |
674 | } | |
675 | ||
676 | u_int | |
677 | key_size(const Key *k) | |
678 | { | |
679 | switch (k->type) { | |
680 | case KEY_RSA1: | |
681 | case KEY_RSA: | |
682 | return BN_num_bits(k->rsa->n); | |
683 | case KEY_DSA: | |
684 | return BN_num_bits(k->dsa->p); | |
685 | } | |
686 | return 0; | |
687 | } | |
688 | ||
689 | static RSA * | |
690 | rsa_generate_private_key(u_int bits) | |
691 | { | |
692 | RSA *private; | |
693 | ||
694 | private = RSA_generate_key(bits, RSA_F4, NULL, NULL); | |
695 | if (private == NULL) | |
696 | fatal("rsa_generate_private_key: key generation failed."); | |
697 | return private; | |
698 | } | |
699 | ||
700 | static DSA* | |
701 | dsa_generate_private_key(u_int bits) | |
702 | { | |
703 | DSA *private = DSA_generate_parameters(bits, NULL, 0, NULL, NULL, NULL, NULL); | |
704 | ||
705 | if (private == NULL) | |
706 | fatal("dsa_generate_private_key: DSA_generate_parameters failed"); | |
707 | if (!DSA_generate_key(private)) | |
708 | fatal("dsa_generate_private_key: DSA_generate_key failed."); | |
709 | if (private == NULL) | |
710 | fatal("dsa_generate_private_key: NULL."); | |
711 | return private; | |
712 | } | |
713 | ||
714 | Key * | |
715 | key_generate(int type, u_int bits) | |
716 | { | |
717 | Key *k = key_new(KEY_UNSPEC); | |
718 | switch (type) { | |
719 | case KEY_DSA: | |
720 | k->dsa = dsa_generate_private_key(bits); | |
721 | break; | |
722 | case KEY_RSA: | |
723 | case KEY_RSA1: | |
724 | k->rsa = rsa_generate_private_key(bits); | |
725 | break; | |
726 | default: | |
727 | fatal("key_generate: unknown type %d", type); | |
728 | } | |
729 | k->type = type; | |
730 | return k; | |
731 | } | |
732 | ||
733 | Key * | |
734 | key_from_private(const Key *k) | |
735 | { | |
736 | Key *n = NULL; | |
737 | switch (k->type) { | |
738 | case KEY_DSA: | |
739 | n = key_new(k->type); | |
740 | if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) || | |
741 | (BN_copy(n->dsa->q, k->dsa->q) == NULL) || | |
742 | (BN_copy(n->dsa->g, k->dsa->g) == NULL) || | |
743 | (BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL)) | |
744 | fatal("key_from_private: BN_copy failed"); | |
745 | break; | |
746 | case KEY_RSA: | |
747 | case KEY_RSA1: | |
748 | n = key_new(k->type); | |
749 | if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) || | |
750 | (BN_copy(n->rsa->e, k->rsa->e) == NULL)) | |
751 | fatal("key_from_private: BN_copy failed"); | |
752 | break; | |
753 | default: | |
754 | fatal("key_from_private: unknown type %d", k->type); | |
755 | break; | |
756 | } | |
757 | return n; | |
758 | } | |
759 | ||
760 | int | |
761 | key_type_from_name(char *name) | |
762 | { | |
763 | if (strcmp(name, "rsa1") == 0) { | |
764 | return KEY_RSA1; | |
765 | } else if (strcmp(name, "rsa") == 0) { | |
766 | return KEY_RSA; | |
767 | } else if (strcmp(name, "dsa") == 0) { | |
768 | return KEY_DSA; | |
769 | } else if (strcmp(name, "ssh-rsa") == 0) { | |
770 | return KEY_RSA; | |
771 | } else if (strcmp(name, "ssh-dss") == 0) { | |
772 | return KEY_DSA; | |
773 | } | |
774 | debug2("key_type_from_name: unknown key type '%s'", name); | |
775 | return KEY_UNSPEC; | |
776 | } | |
777 | ||
778 | int | |
779 | key_names_valid2(const char *names) | |
780 | { | |
781 | char *s, *cp, *p; | |
782 | ||
783 | if (names == NULL || strcmp(names, "") == 0) | |
784 | return 0; | |
785 | s = cp = xstrdup(names); | |
786 | for ((p = strsep(&cp, ",")); p && *p != '\0'; | |
787 | (p = strsep(&cp, ","))) { | |
788 | switch (key_type_from_name(p)) { | |
789 | case KEY_RSA1: | |
790 | case KEY_UNSPEC: | |
791 | xfree(s); | |
792 | return 0; | |
793 | } | |
794 | } | |
795 | debug3("key names ok: [%s]", names); | |
796 | xfree(s); | |
797 | return 1; | |
798 | } | |
799 | ||
800 | Key * | |
801 | key_from_blob(const u_char *blob, u_int blen) | |
802 | { | |
803 | Buffer b; | |
804 | int rlen, type; | |
805 | char *ktype = NULL; | |
806 | Key *key = NULL; | |
807 | ||
808 | #ifdef DEBUG_PK | |
809 | dump_base64(stderr, blob, blen); | |
810 | #endif | |
811 | buffer_init(&b); | |
812 | buffer_append(&b, blob, blen); | |
813 | if ((ktype = buffer_get_string_ret(&b, NULL)) == NULL) { | |
814 | error("key_from_blob: can't read key type"); | |
815 | goto out; | |
816 | } | |
817 | ||
818 | type = key_type_from_name(ktype); | |
819 | ||
820 | switch (type) { | |
821 | case KEY_RSA: | |
822 | key = key_new(type); | |
823 | if (buffer_get_bignum2_ret(&b, key->rsa->e) == -1 || | |
824 | buffer_get_bignum2_ret(&b, key->rsa->n) == -1) { | |
825 | error("key_from_blob: can't read rsa key"); | |
826 | key_free(key); | |
827 | key = NULL; | |
828 | goto out; | |
829 | } | |
830 | #ifdef DEBUG_PK | |
831 | RSA_print_fp(stderr, key->rsa, 8); | |
832 | #endif | |
833 | break; | |
834 | case KEY_DSA: | |
835 | key = key_new(type); | |
836 | if (buffer_get_bignum2_ret(&b, key->dsa->p) == -1 || | |
837 | buffer_get_bignum2_ret(&b, key->dsa->q) == -1 || | |
838 | buffer_get_bignum2_ret(&b, key->dsa->g) == -1 || | |
839 | buffer_get_bignum2_ret(&b, key->dsa->pub_key) == -1) { | |
840 | error("key_from_blob: can't read dsa key"); | |
841 | key_free(key); | |
842 | key = NULL; | |
843 | goto out; | |
844 | } | |
845 | #ifdef DEBUG_PK | |
846 | DSA_print_fp(stderr, key->dsa, 8); | |
847 | #endif | |
848 | break; | |
849 | case KEY_UNSPEC: | |
850 | key = key_new(type); | |
851 | break; | |
852 | default: | |
853 | error("key_from_blob: cannot handle type %s", ktype); | |
854 | goto out; | |
855 | } | |
856 | rlen = buffer_len(&b); | |
857 | if (key != NULL && rlen != 0) | |
858 | error("key_from_blob: remaining bytes in key blob %d", rlen); | |
859 | out: | |
860 | if (ktype != NULL) | |
861 | xfree(ktype); | |
862 | buffer_free(&b); | |
863 | return key; | |
864 | } | |
865 | ||
866 | int | |
867 | key_to_blob(const Key *key, u_char **blobp, u_int *lenp) | |
868 | { | |
869 | Buffer b; | |
870 | int len; | |
871 | ||
872 | if (key == NULL) { | |
873 | error("key_to_blob: key == NULL"); | |
874 | return 0; | |
875 | } | |
876 | buffer_init(&b); | |
877 | switch (key->type) { | |
878 | case KEY_DSA: | |
879 | buffer_put_cstring(&b, key_ssh_name(key)); | |
880 | buffer_put_bignum2(&b, key->dsa->p); | |
881 | buffer_put_bignum2(&b, key->dsa->q); | |
882 | buffer_put_bignum2(&b, key->dsa->g); | |
883 | buffer_put_bignum2(&b, key->dsa->pub_key); | |
884 | break; | |
885 | case KEY_RSA: | |
886 | buffer_put_cstring(&b, key_ssh_name(key)); | |
887 | buffer_put_bignum2(&b, key->rsa->e); | |
888 | buffer_put_bignum2(&b, key->rsa->n); | |
889 | break; | |
890 | default: | |
891 | error("key_to_blob: unsupported key type %d", key->type); | |
892 | buffer_free(&b); | |
893 | return 0; | |
894 | } | |
895 | len = buffer_len(&b); | |
896 | if (lenp != NULL) | |
897 | *lenp = len; | |
898 | if (blobp != NULL) { | |
899 | *blobp = xmalloc(len); | |
900 | memcpy(*blobp, buffer_ptr(&b), len); | |
901 | } | |
902 | memset(buffer_ptr(&b), 0, len); | |
903 | buffer_free(&b); | |
904 | return len; | |
905 | } | |
906 | ||
907 | int | |
908 | key_sign( | |
909 | const Key *key, | |
910 | u_char **sigp, u_int *lenp, | |
911 | const u_char *data, u_int datalen) | |
912 | { | |
913 | switch (key->type) { | |
914 | case KEY_DSA: | |
915 | return ssh_dss_sign(key, sigp, lenp, data, datalen); | |
916 | case KEY_RSA: | |
917 | return ssh_rsa_sign(key, sigp, lenp, data, datalen); | |
918 | default: | |
919 | error("key_sign: invalid key type %d", key->type); | |
920 | return -1; | |
921 | } | |
922 | } | |
923 | ||
924 | /* | |
925 | * key_verify returns 1 for a correct signature, 0 for an incorrect signature | |
926 | * and -1 on error. | |
927 | */ | |
928 | int | |
929 | key_verify( | |
930 | const Key *key, | |
931 | const u_char *signature, u_int signaturelen, | |
932 | const u_char *data, u_int datalen) | |
933 | { | |
934 | if (signaturelen == 0) | |
935 | return -1; | |
936 | ||
937 | switch (key->type) { | |
938 | case KEY_DSA: | |
939 | return ssh_dss_verify(key, signature, signaturelen, data, datalen); | |
940 | case KEY_RSA: | |
941 | return ssh_rsa_verify(key, signature, signaturelen, data, datalen); | |
942 | default: | |
943 | error("key_verify: invalid key type %d", key->type); | |
944 | return -1; | |
945 | } | |
946 | } | |
947 | ||
948 | /* Converts a private to a public key */ | |
949 | Key * | |
950 | key_demote(const Key *k) | |
951 | { | |
952 | Key *pk; | |
953 | ||
954 | pk = xcalloc(1, sizeof(*pk)); | |
955 | pk->type = k->type; | |
956 | pk->flags = k->flags; | |
957 | pk->dsa = NULL; | |
958 | pk->rsa = NULL; | |
959 | ||
960 | switch (k->type) { | |
961 | case KEY_RSA1: | |
962 | case KEY_RSA: | |
963 | if ((pk->rsa = RSA_new()) == NULL) | |
964 | fatal("key_demote: RSA_new failed"); | |
965 | if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL) | |
966 | fatal("key_demote: BN_dup failed"); | |
967 | if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL) | |
968 | fatal("key_demote: BN_dup failed"); | |
969 | break; | |
970 | case KEY_DSA: | |
971 | if ((pk->dsa = DSA_new()) == NULL) | |
972 | fatal("key_demote: DSA_new failed"); | |
973 | if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL) | |
974 | fatal("key_demote: BN_dup failed"); | |
975 | if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL) | |
976 | fatal("key_demote: BN_dup failed"); | |
977 | if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL) | |
978 | fatal("key_demote: BN_dup failed"); | |
979 | if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL) | |
980 | fatal("key_demote: BN_dup failed"); | |
981 | break; | |
982 | default: | |
983 | fatal("key_free: bad key type %d", k->type); | |
984 | break; | |
985 | } | |
986 | ||
987 | return (pk); | |
988 | } |