Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2000 Markus Friedl. All rights reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * 1. Redistributions of source code must retain the above copyright |
| 8 | * notice, this list of conditions and the following disclaimer. |
| 9 | * 2. Redistributions in binary form must reproduce the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer in the |
| 11 | * documentation and/or other materials provided with the distribution. |
| 12 | * 3. All advertising materials mentioning features or use of this software |
| 13 | * must display the following acknowledgement: |
| 14 | * This product includes software developed by Markus Friedl. |
| 15 | * 4. The name of the author may not be used to endorse or promote products |
| 16 | * derived from this software without specific prior written permission. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 19 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 20 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 21 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 22 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 23 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 24 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 25 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 27 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 28 | */ |
| 29 | /* |
| 30 | * read_bignum(): |
| 31 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 32 | */ |
| 33 | |
| 34 | #include "includes.h" |
Damien Miller | 5f05637 | 2000-04-16 12:31:48 +1000 | [diff] [blame] | 35 | #include "ssh.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 36 | #include <openssl/rsa.h> |
| 37 | #include <openssl/dsa.h> |
| 38 | #include <openssl/evp.h> |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 39 | #include "xmalloc.h" |
| 40 | #include "key.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 41 | #include "dsa.h" |
| 42 | #include "uuencode.h" |
| 43 | |
| 44 | #define SSH_DSS "ssh-dss" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 45 | |
| 46 | Key * |
| 47 | key_new(int type) |
| 48 | { |
| 49 | Key *k; |
| 50 | RSA *rsa; |
| 51 | DSA *dsa; |
| 52 | k = xmalloc(sizeof(*k)); |
| 53 | k->type = type; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 54 | k->dsa = NULL; |
| 55 | k->rsa = NULL; |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 56 | switch (k->type) { |
| 57 | case KEY_RSA: |
| 58 | rsa = RSA_new(); |
| 59 | rsa->n = BN_new(); |
| 60 | rsa->e = BN_new(); |
| 61 | k->rsa = rsa; |
| 62 | break; |
| 63 | case KEY_DSA: |
| 64 | dsa = DSA_new(); |
| 65 | dsa->p = BN_new(); |
| 66 | dsa->q = BN_new(); |
| 67 | dsa->g = BN_new(); |
| 68 | dsa->pub_key = BN_new(); |
| 69 | k->dsa = dsa; |
| 70 | break; |
| 71 | case KEY_EMPTY: |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 72 | break; |
| 73 | default: |
| 74 | fatal("key_new: bad key type %d", k->type); |
| 75 | break; |
| 76 | } |
| 77 | return k; |
| 78 | } |
| 79 | void |
| 80 | key_free(Key *k) |
| 81 | { |
| 82 | switch (k->type) { |
| 83 | case KEY_RSA: |
| 84 | if (k->rsa != NULL) |
| 85 | RSA_free(k->rsa); |
| 86 | k->rsa = NULL; |
| 87 | break; |
| 88 | case KEY_DSA: |
| 89 | if (k->dsa != NULL) |
| 90 | DSA_free(k->dsa); |
| 91 | k->dsa = NULL; |
| 92 | break; |
| 93 | default: |
| 94 | fatal("key_free: bad key type %d", k->type); |
| 95 | break; |
| 96 | } |
| 97 | xfree(k); |
| 98 | } |
| 99 | int |
| 100 | key_equal(Key *a, Key *b) |
| 101 | { |
| 102 | if (a == NULL || b == NULL || a->type != b->type) |
| 103 | return 0; |
| 104 | switch (a->type) { |
| 105 | case KEY_RSA: |
| 106 | return a->rsa != NULL && b->rsa != NULL && |
| 107 | BN_cmp(a->rsa->e, b->rsa->e) == 0 && |
| 108 | BN_cmp(a->rsa->n, b->rsa->n) == 0; |
| 109 | break; |
| 110 | case KEY_DSA: |
| 111 | return a->dsa != NULL && b->dsa != NULL && |
| 112 | BN_cmp(a->dsa->p, b->dsa->p) == 0 && |
| 113 | BN_cmp(a->dsa->q, b->dsa->q) == 0 && |
| 114 | BN_cmp(a->dsa->g, b->dsa->g) == 0 && |
| 115 | BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0; |
| 116 | break; |
| 117 | default: |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 118 | fatal("key_equal: bad key type %d", a->type); |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 119 | break; |
| 120 | } |
| 121 | return 0; |
| 122 | } |
| 123 | |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 124 | /* |
| 125 | * Generate key fingerprint in ascii format. |
| 126 | * Based on ideas and code from Bjoern Groenvall <bg@sics.se> |
| 127 | */ |
| 128 | char * |
| 129 | key_fingerprint(Key *k) |
| 130 | { |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 131 | static char retval[(EVP_MAX_MD_SIZE+1)*3]; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 132 | unsigned char *blob = NULL; |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 133 | int len = 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 134 | int nlen, elen; |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 135 | |
| 136 | switch (k->type) { |
| 137 | case KEY_RSA: |
| 138 | nlen = BN_num_bytes(k->rsa->n); |
| 139 | elen = BN_num_bytes(k->rsa->e); |
| 140 | len = nlen + elen; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 141 | blob = xmalloc(len); |
| 142 | BN_bn2bin(k->rsa->n, blob); |
| 143 | BN_bn2bin(k->rsa->e, blob + nlen); |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 144 | break; |
| 145 | case KEY_DSA: |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 146 | dsa_make_key_blob(k, &blob, &len); |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 147 | break; |
| 148 | default: |
| 149 | fatal("key_fingerprint: bad key type %d", k->type); |
| 150 | break; |
| 151 | } |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 152 | retval[0] = '\0'; |
| 153 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 154 | if (blob != NULL) { |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 155 | int i; |
| 156 | unsigned char digest[EVP_MAX_MD_SIZE]; |
| 157 | EVP_MD *md = EVP_md5(); |
| 158 | EVP_MD_CTX ctx; |
| 159 | EVP_DigestInit(&ctx, md); |
| 160 | EVP_DigestUpdate(&ctx, blob, len); |
| 161 | EVP_DigestFinal(&ctx, digest, NULL); |
| 162 | for(i = 0; i < md->md_size; i++) { |
| 163 | char hex[4]; |
| 164 | snprintf(hex, sizeof(hex), "%02x:", digest[i]); |
| 165 | strlcat(retval, hex, sizeof(retval)); |
| 166 | } |
| 167 | retval[strlen(retval) - 1] = '\0'; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 168 | memset(blob, 0, len); |
| 169 | xfree(blob); |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 170 | } |
| 171 | return retval; |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * Reads a multiple-precision integer in decimal from the buffer, and advances |
| 176 | * the pointer. The integer must already be initialized. This function is |
| 177 | * permitted to modify the buffer. This leaves *cpp to point just beyond the |
| 178 | * last processed (and maybe modified) character. Note that this may modify |
| 179 | * the buffer containing the number. |
| 180 | */ |
| 181 | int |
| 182 | read_bignum(char **cpp, BIGNUM * value) |
| 183 | { |
| 184 | char *cp = *cpp; |
| 185 | int old; |
| 186 | |
| 187 | /* Skip any leading whitespace. */ |
| 188 | for (; *cp == ' ' || *cp == '\t'; cp++) |
| 189 | ; |
| 190 | |
| 191 | /* Check that it begins with a decimal digit. */ |
| 192 | if (*cp < '0' || *cp > '9') |
| 193 | return 0; |
| 194 | |
| 195 | /* Save starting position. */ |
| 196 | *cpp = cp; |
| 197 | |
| 198 | /* Move forward until all decimal digits skipped. */ |
| 199 | for (; *cp >= '0' && *cp <= '9'; cp++) |
| 200 | ; |
| 201 | |
| 202 | /* Save the old terminating character, and replace it by \0. */ |
| 203 | old = *cp; |
| 204 | *cp = 0; |
| 205 | |
| 206 | /* Parse the number. */ |
| 207 | if (BN_dec2bn(&value, *cpp) == 0) |
| 208 | return 0; |
| 209 | |
| 210 | /* Restore old terminating character. */ |
| 211 | *cp = old; |
| 212 | |
| 213 | /* Move beyond the number and return success. */ |
| 214 | *cpp = cp; |
| 215 | return 1; |
| 216 | } |
| 217 | int |
| 218 | write_bignum(FILE *f, BIGNUM *num) |
| 219 | { |
| 220 | char *buf = BN_bn2dec(num); |
| 221 | if (buf == NULL) { |
| 222 | error("write_bignum: BN_bn2dec() failed"); |
| 223 | return 0; |
| 224 | } |
| 225 | fprintf(f, " %s", buf); |
| 226 | free(buf); |
| 227 | return 1; |
| 228 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 229 | unsigned int |
| 230 | key_read(Key *ret, char **cpp) |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 231 | { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 232 | Key *k; |
| 233 | unsigned int bits = 0; |
| 234 | char *cp; |
| 235 | int len, n; |
| 236 | unsigned char *blob; |
| 237 | |
| 238 | cp = *cpp; |
| 239 | |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 240 | switch(ret->type) { |
| 241 | case KEY_RSA: |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 242 | /* Get number of bits. */ |
| 243 | if (*cp < '0' || *cp > '9') |
| 244 | return 0; /* Bad bit count... */ |
| 245 | for (bits = 0; *cp >= '0' && *cp <= '9'; cp++) |
| 246 | bits = 10 * bits + *cp - '0'; |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 247 | if (bits == 0) |
| 248 | return 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 249 | *cpp = cp; |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 250 | /* Get public exponent, public modulus. */ |
| 251 | if (!read_bignum(cpp, ret->rsa->e)) |
| 252 | return 0; |
| 253 | if (!read_bignum(cpp, ret->rsa->n)) |
| 254 | return 0; |
| 255 | break; |
| 256 | case KEY_DSA: |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 257 | if (strncmp(cp, SSH_DSS " ", 7) != 0) |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 258 | return 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 259 | cp += 7; |
| 260 | len = 2*strlen(cp); |
| 261 | blob = xmalloc(len); |
| 262 | n = uudecode(cp, blob, len); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 263 | if (n < 0) { |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 264 | error("key_read: uudecode %s failed", cp); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 265 | return 0; |
| 266 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 267 | k = dsa_key_from_blob(blob, n); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 268 | if (k == NULL) { |
| 269 | error("key_read: dsa_key_from_blob %s failed", cp); |
| 270 | return 0; |
| 271 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 272 | xfree(blob); |
| 273 | if (ret->dsa != NULL) |
| 274 | DSA_free(ret->dsa); |
| 275 | ret->dsa = k->dsa; |
| 276 | k->dsa = NULL; |
| 277 | key_free(k); |
| 278 | bits = BN_num_bits(ret->dsa->p); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 279 | /* advance cp: skip whitespace and data */ |
| 280 | while (*cp == ' ' || *cp == '\t') |
| 281 | cp++; |
| 282 | while (*cp != '\0' && *cp != ' ' && *cp != '\t') |
| 283 | cp++; |
| 284 | *cpp = cp; |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 285 | break; |
| 286 | default: |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 287 | fatal("key_read: bad key type: %d", ret->type); |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 288 | break; |
| 289 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 290 | return bits; |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 291 | } |
| 292 | int |
| 293 | key_write(Key *key, FILE *f) |
| 294 | { |
| 295 | int success = 0; |
| 296 | unsigned int bits = 0; |
| 297 | |
| 298 | if (key->type == KEY_RSA && key->rsa != NULL) { |
| 299 | /* size of modulus 'n' */ |
| 300 | bits = BN_num_bits(key->rsa->n); |
| 301 | fprintf(f, "%u", bits); |
| 302 | if (write_bignum(f, key->rsa->e) && |
| 303 | write_bignum(f, key->rsa->n)) { |
| 304 | success = 1; |
| 305 | } else { |
| 306 | error("key_write: failed for RSA key"); |
| 307 | } |
| 308 | } else if (key->type == KEY_DSA && key->dsa != NULL) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 309 | int len, n; |
| 310 | unsigned char *blob, *uu; |
| 311 | dsa_make_key_blob(key, &blob, &len); |
| 312 | uu = xmalloc(2*len); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 313 | n = uuencode(blob, len, uu, 2*len); |
| 314 | if (n > 0) { |
| 315 | fprintf(f, "%s %s", SSH_DSS, uu); |
| 316 | success = 1; |
| 317 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 318 | xfree(blob); |
| 319 | xfree(uu); |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 320 | } |
| 321 | return success; |
| 322 | } |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 323 | char * |
| 324 | key_type(Key *k) |
| 325 | { |
| 326 | switch (k->type) { |
| 327 | case KEY_RSA: |
| 328 | return "RSA"; |
| 329 | break; |
| 330 | case KEY_DSA: |
| 331 | return "DSA"; |
| 332 | break; |
| 333 | } |
| 334 | return "unknown"; |
| 335 | } |