| 1 | /************************************************* |
| 2 | * Exim - an Internet mail transport agent * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* Copyright (c) University of Cambridge, 1995 - 2007 */ |
| 6 | /* See the file NOTICE for conditions of use and distribution. */ |
| 7 | |
| 8 | /* Code for DKIM support. Other DKIM relevant code is in |
| 9 | receive.c, transport.c and transports/smtp.c */ |
| 10 | |
| 11 | #include "exim.h" |
| 12 | |
| 13 | #ifndef DISABLE_DKIM |
| 14 | |
| 15 | #include "pdkim/pdkim.h" |
| 16 | |
| 17 | pdkim_ctx *dkim_verify_ctx = NULL; |
| 18 | pdkim_signature *dkim_signatures = NULL; |
| 19 | pdkim_signature *dkim_cur_sig = NULL; |
| 20 | |
| 21 | int dkim_exim_query_dns_txt(char *name, char *answer) { |
| 22 | dns_answer dnsa; |
| 23 | dns_scan dnss; |
| 24 | dns_record *rr; |
| 25 | |
| 26 | lookup_dnssec_authenticated = NULL; |
| 27 | if (dns_lookup(&dnsa, (uschar *)name, T_TXT, NULL) != DNS_SUCCEED) return PDKIM_FAIL; |
| 28 | |
| 29 | /* Search for TXT record */ |
| 30 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); |
| 31 | rr != NULL; |
| 32 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) |
| 33 | if (rr->type == T_TXT) break; |
| 34 | |
| 35 | /* Copy record content to the answer buffer */ |
| 36 | if (rr != NULL) { |
| 37 | int rr_offset = 0; |
| 38 | int answer_offset = 0; |
| 39 | while (rr_offset < rr->size) { |
| 40 | uschar len = (rr->data)[rr_offset++]; |
| 41 | snprintf(answer+(answer_offset), |
| 42 | PDKIM_DNS_TXT_MAX_RECLEN-(answer_offset), |
| 43 | "%.*s", (int)len, (char *)((rr->data)+rr_offset)); |
| 44 | rr_offset+=len; |
| 45 | answer_offset+=len; |
| 46 | if (answer_offset >= PDKIM_DNS_TXT_MAX_RECLEN) { |
| 47 | return PDKIM_FAIL; |
| 48 | } |
| 49 | } |
| 50 | } |
| 51 | else return PDKIM_FAIL; |
| 52 | |
| 53 | return PDKIM_OK; |
| 54 | } |
| 55 | |
| 56 | |
| 57 | void dkim_exim_verify_init(void) { |
| 58 | |
| 59 | /* Free previous context if there is one */ |
| 60 | if (dkim_verify_ctx) pdkim_free_ctx(dkim_verify_ctx); |
| 61 | |
| 62 | /* Create new context */ |
| 63 | dkim_verify_ctx = pdkim_init_verify(PDKIM_INPUT_SMTP, |
| 64 | &dkim_exim_query_dns_txt |
| 65 | ); |
| 66 | |
| 67 | if (dkim_verify_ctx != NULL) { |
| 68 | dkim_collect_input = TRUE; |
| 69 | pdkim_set_debug_stream(dkim_verify_ctx,debug_file); |
| 70 | } |
| 71 | else dkim_collect_input = FALSE; |
| 72 | |
| 73 | } |
| 74 | |
| 75 | |
| 76 | void dkim_exim_verify_feed(uschar *data, int len) { |
| 77 | if (dkim_collect_input && |
| 78 | pdkim_feed(dkim_verify_ctx, |
| 79 | (char *)data, |
| 80 | len) != PDKIM_OK) dkim_collect_input = FALSE; |
| 81 | } |
| 82 | |
| 83 | |
| 84 | void dkim_exim_verify_finish(void) { |
| 85 | pdkim_signature *sig = NULL; |
| 86 | int dkim_signers_size = 0; |
| 87 | int dkim_signers_ptr = 0; |
| 88 | dkim_signers = NULL; |
| 89 | |
| 90 | /* Delete eventual previous signature chain */ |
| 91 | dkim_signatures = NULL; |
| 92 | |
| 93 | /* If we have arrived here with dkim_collect_input == FALSE, it |
| 94 | means there was a processing error somewhere along the way. |
| 95 | Log the incident and disable futher verification. */ |
| 96 | if (!dkim_collect_input) { |
| 97 | log_write(0, LOG_MAIN, "DKIM: Error while running this message through validation, disabling signature verification."); |
| 98 | dkim_disable_verify = TRUE; |
| 99 | return; |
| 100 | } |
| 101 | dkim_collect_input = FALSE; |
| 102 | |
| 103 | /* Finish DKIM operation and fetch link to signatures chain */ |
| 104 | if (pdkim_feed_finish(dkim_verify_ctx,&dkim_signatures) != PDKIM_OK) return; |
| 105 | |
| 106 | sig = dkim_signatures; |
| 107 | while (sig != NULL) { |
| 108 | int size = 0; |
| 109 | int ptr = 0; |
| 110 | /* Log a line for each signature */ |
| 111 | uschar *logmsg = string_append(NULL, &size, &ptr, 5, |
| 112 | |
| 113 | string_sprintf( "d=%s s=%s c=%s/%s a=%s ", |
| 114 | sig->domain, |
| 115 | sig->selector, |
| 116 | (sig->canon_headers == PDKIM_CANON_SIMPLE)?"simple":"relaxed", |
| 117 | (sig->canon_body == PDKIM_CANON_SIMPLE)?"simple":"relaxed", |
| 118 | (sig->algo == PDKIM_ALGO_RSA_SHA256)?"rsa-sha256":"rsa-sha1" |
| 119 | ), |
| 120 | ((sig->identity != NULL)? |
| 121 | string_sprintf("i=%s ", sig->identity) |
| 122 | : |
| 123 | US"" |
| 124 | ), |
| 125 | ((sig->created > 0)? |
| 126 | string_sprintf("t=%lu ", sig->created) |
| 127 | : |
| 128 | US"" |
| 129 | ), |
| 130 | ((sig->expires > 0)? |
| 131 | string_sprintf("x=%lu ", sig->expires) |
| 132 | : |
| 133 | US"" |
| 134 | ), |
| 135 | ((sig->bodylength > -1)? |
| 136 | string_sprintf("l=%lu ", sig->bodylength) |
| 137 | : |
| 138 | US"" |
| 139 | ) |
| 140 | ); |
| 141 | |
| 142 | switch(sig->verify_status) { |
| 143 | case PDKIM_VERIFY_NONE: |
| 144 | logmsg = string_append(logmsg, &size, &ptr, 1, "[not verified]"); |
| 145 | break; |
| 146 | case PDKIM_VERIFY_INVALID: |
| 147 | logmsg = string_append(logmsg, &size, &ptr, 1, "[invalid - "); |
| 148 | switch (sig->verify_ext_status) { |
| 149 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: |
| 150 | logmsg = string_append(logmsg, &size, &ptr, 1, "public key record (currently?) unavailable]"); |
| 151 | break; |
| 152 | case PDKIM_VERIFY_INVALID_BUFFER_SIZE: |
| 153 | logmsg = string_append(logmsg, &size, &ptr, 1, "overlong public key record]"); |
| 154 | break; |
| 155 | case PDKIM_VERIFY_INVALID_PUBKEY_PARSING: |
| 156 | logmsg = string_append(logmsg, &size, &ptr, 1, "syntax error in public key record]"); |
| 157 | break; |
| 158 | default: |
| 159 | logmsg = string_append(logmsg, &size, &ptr, 1, "unspecified problem]"); |
| 160 | } |
| 161 | break; |
| 162 | case PDKIM_VERIFY_FAIL: |
| 163 | logmsg = string_append(logmsg, &size, &ptr, 1, "[verification failed - "); |
| 164 | switch (sig->verify_ext_status) { |
| 165 | case PDKIM_VERIFY_FAIL_BODY: |
| 166 | logmsg = string_append(logmsg, &size, &ptr, 1, "body hash mismatch (body probably modified in transit)]"); |
| 167 | break; |
| 168 | case PDKIM_VERIFY_FAIL_MESSAGE: |
| 169 | logmsg = string_append(logmsg, &size, &ptr, 1, "signature did not verify (headers probably modified in transit)]"); |
| 170 | break; |
| 171 | default: |
| 172 | logmsg = string_append(logmsg, &size, &ptr, 1, "unspecified reason]"); |
| 173 | } |
| 174 | break; |
| 175 | case PDKIM_VERIFY_PASS: |
| 176 | logmsg = string_append(logmsg, &size, &ptr, 1, "[verification succeeded]"); |
| 177 | break; |
| 178 | } |
| 179 | |
| 180 | logmsg[ptr] = '\0'; |
| 181 | log_write(0, LOG_MAIN, "DKIM: %s", logmsg); |
| 182 | |
| 183 | /* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */ |
| 184 | dkim_signers = string_append(dkim_signers, |
| 185 | &dkim_signers_size, |
| 186 | &dkim_signers_ptr, |
| 187 | 2, |
| 188 | sig->domain, |
| 189 | ":" |
| 190 | ); |
| 191 | |
| 192 | if (sig->identity != NULL) { |
| 193 | dkim_signers = string_append(dkim_signers, |
| 194 | &dkim_signers_size, |
| 195 | &dkim_signers_ptr, |
| 196 | 2, |
| 197 | sig->identity, |
| 198 | ":" |
| 199 | ); |
| 200 | } |
| 201 | |
| 202 | /* Process next signature */ |
| 203 | sig = sig->next; |
| 204 | } |
| 205 | |
| 206 | /* NULL-terminate and chop the last colon from the domain list */ |
| 207 | if (dkim_signers != NULL) { |
| 208 | dkim_signers[dkim_signers_ptr] = '\0'; |
| 209 | if (Ustrlen(dkim_signers) > 0) |
| 210 | dkim_signers[Ustrlen(dkim_signers)-1] = '\0'; |
| 211 | } |
| 212 | } |
| 213 | |
| 214 | |
| 215 | void dkim_exim_acl_setup(uschar *id) { |
| 216 | pdkim_signature *sig = dkim_signatures; |
| 217 | dkim_cur_sig = NULL; |
| 218 | dkim_cur_signer = id; |
| 219 | if (dkim_disable_verify || |
| 220 | !id || !dkim_verify_ctx) return; |
| 221 | /* Find signature to run ACL on */ |
| 222 | while (sig != NULL) { |
| 223 | uschar *cmp_val = NULL; |
| 224 | if (Ustrchr(id,'@') != NULL) cmp_val = (uschar *)sig->identity; |
| 225 | else cmp_val = (uschar *)sig->domain; |
| 226 | if (cmp_val && (strcmpic(cmp_val,id) == 0)) { |
| 227 | dkim_cur_sig = sig; |
| 228 | /* The "dkim_domain" and "dkim_selector" expansion variables have |
| 229 | related globals, since they are used in the signing code too. |
| 230 | Instead of inventing separate names for verification, we set |
| 231 | them here. This is easy since a domain and selector is guaranteed |
| 232 | to be in a signature. The other dkim_* expansion items are |
| 233 | dynamically fetched from dkim_cur_sig at expansion time (see |
| 234 | function below). */ |
| 235 | dkim_signing_domain = (uschar *)sig->domain; |
| 236 | dkim_signing_selector = (uschar *)sig->selector; |
| 237 | return; |
| 238 | } |
| 239 | sig = sig->next; |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | |
| 244 | uschar *dkim_exim_expand_query(int what) { |
| 245 | |
| 246 | if (!dkim_verify_ctx || |
| 247 | dkim_disable_verify || |
| 248 | !dkim_cur_sig) return dkim_exim_expand_defaults(what); |
| 249 | |
| 250 | switch(what) { |
| 251 | case DKIM_ALGO: |
| 252 | switch(dkim_cur_sig->algo) { |
| 253 | case PDKIM_ALGO_RSA_SHA1: |
| 254 | return US"rsa-sha1"; |
| 255 | case PDKIM_ALGO_RSA_SHA256: |
| 256 | default: |
| 257 | return US"rsa-sha256"; |
| 258 | } |
| 259 | case DKIM_BODYLENGTH: |
| 260 | return (dkim_cur_sig->bodylength >= 0)? |
| 261 | (uschar *)string_sprintf(OFF_T_FMT,(LONGLONG_T)dkim_cur_sig->bodylength) |
| 262 | :dkim_exim_expand_defaults(what); |
| 263 | case DKIM_CANON_BODY: |
| 264 | switch(dkim_cur_sig->canon_body) { |
| 265 | case PDKIM_CANON_RELAXED: |
| 266 | return US"relaxed"; |
| 267 | case PDKIM_CANON_SIMPLE: |
| 268 | default: |
| 269 | return US"simple"; |
| 270 | } |
| 271 | case DKIM_CANON_HEADERS: |
| 272 | switch(dkim_cur_sig->canon_headers) { |
| 273 | case PDKIM_CANON_RELAXED: |
| 274 | return US"relaxed"; |
| 275 | case PDKIM_CANON_SIMPLE: |
| 276 | default: |
| 277 | return US"simple"; |
| 278 | } |
| 279 | case DKIM_COPIEDHEADERS: |
| 280 | return dkim_cur_sig->copiedheaders? |
| 281 | (uschar *)(dkim_cur_sig->copiedheaders) |
| 282 | :dkim_exim_expand_defaults(what); |
| 283 | case DKIM_CREATED: |
| 284 | return (dkim_cur_sig->created > 0)? |
| 285 | (uschar *)string_sprintf("%llu",dkim_cur_sig->created) |
| 286 | :dkim_exim_expand_defaults(what); |
| 287 | case DKIM_EXPIRES: |
| 288 | return (dkim_cur_sig->expires > 0)? |
| 289 | (uschar *)string_sprintf("%llu",dkim_cur_sig->expires) |
| 290 | :dkim_exim_expand_defaults(what); |
| 291 | case DKIM_HEADERNAMES: |
| 292 | return dkim_cur_sig->headernames? |
| 293 | (uschar *)(dkim_cur_sig->headernames) |
| 294 | :dkim_exim_expand_defaults(what); |
| 295 | case DKIM_IDENTITY: |
| 296 | return dkim_cur_sig->identity? |
| 297 | (uschar *)(dkim_cur_sig->identity) |
| 298 | :dkim_exim_expand_defaults(what); |
| 299 | case DKIM_KEY_GRANULARITY: |
| 300 | return dkim_cur_sig->pubkey? |
| 301 | (dkim_cur_sig->pubkey->granularity? |
| 302 | (uschar *)(dkim_cur_sig->pubkey->granularity) |
| 303 | :dkim_exim_expand_defaults(what) |
| 304 | ) |
| 305 | :dkim_exim_expand_defaults(what); |
| 306 | case DKIM_KEY_SRVTYPE: |
| 307 | return dkim_cur_sig->pubkey? |
| 308 | (dkim_cur_sig->pubkey->srvtype? |
| 309 | (uschar *)(dkim_cur_sig->pubkey->srvtype) |
| 310 | :dkim_exim_expand_defaults(what) |
| 311 | ) |
| 312 | :dkim_exim_expand_defaults(what); |
| 313 | case DKIM_KEY_NOTES: |
| 314 | return dkim_cur_sig->pubkey? |
| 315 | (dkim_cur_sig->pubkey->notes? |
| 316 | (uschar *)(dkim_cur_sig->pubkey->notes) |
| 317 | :dkim_exim_expand_defaults(what) |
| 318 | ) |
| 319 | :dkim_exim_expand_defaults(what); |
| 320 | case DKIM_KEY_TESTING: |
| 321 | return dkim_cur_sig->pubkey? |
| 322 | (dkim_cur_sig->pubkey->testing? |
| 323 | US"1" |
| 324 | :dkim_exim_expand_defaults(what) |
| 325 | ) |
| 326 | :dkim_exim_expand_defaults(what); |
| 327 | case DKIM_NOSUBDOMAINS: |
| 328 | return dkim_cur_sig->pubkey? |
| 329 | (dkim_cur_sig->pubkey->no_subdomaining? |
| 330 | US"1" |
| 331 | :dkim_exim_expand_defaults(what) |
| 332 | ) |
| 333 | :dkim_exim_expand_defaults(what); |
| 334 | case DKIM_VERIFY_STATUS: |
| 335 | switch(dkim_cur_sig->verify_status) { |
| 336 | case PDKIM_VERIFY_INVALID: |
| 337 | return US"invalid"; |
| 338 | case PDKIM_VERIFY_FAIL: |
| 339 | return US"fail"; |
| 340 | case PDKIM_VERIFY_PASS: |
| 341 | return US"pass"; |
| 342 | case PDKIM_VERIFY_NONE: |
| 343 | default: |
| 344 | return US"none"; |
| 345 | } |
| 346 | case DKIM_VERIFY_REASON: |
| 347 | switch (dkim_cur_sig->verify_ext_status) { |
| 348 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: |
| 349 | return US"pubkey_unavailable"; |
| 350 | case PDKIM_VERIFY_INVALID_PUBKEY_PARSING: |
| 351 | return US"pubkey_syntax"; |
| 352 | case PDKIM_VERIFY_FAIL_BODY: |
| 353 | return US"bodyhash_mismatch"; |
| 354 | case PDKIM_VERIFY_FAIL_MESSAGE: |
| 355 | return US"signature_incorrect"; |
| 356 | } |
| 357 | default: |
| 358 | return US""; |
| 359 | } |
| 360 | } |
| 361 | |
| 362 | |
| 363 | uschar *dkim_exim_expand_defaults(int what) { |
| 364 | switch(what) { |
| 365 | case DKIM_ALGO: return US""; |
| 366 | case DKIM_BODYLENGTH: return US"9999999999999"; |
| 367 | case DKIM_CANON_BODY: return US""; |
| 368 | case DKIM_CANON_HEADERS: return US""; |
| 369 | case DKIM_COPIEDHEADERS: return US""; |
| 370 | case DKIM_CREATED: return US"0"; |
| 371 | case DKIM_EXPIRES: return US"9999999999999"; |
| 372 | case DKIM_HEADERNAMES: return US""; |
| 373 | case DKIM_IDENTITY: return US""; |
| 374 | case DKIM_KEY_GRANULARITY: return US"*"; |
| 375 | case DKIM_KEY_SRVTYPE: return US"*"; |
| 376 | case DKIM_KEY_NOTES: return US""; |
| 377 | case DKIM_KEY_TESTING: return US"0"; |
| 378 | case DKIM_NOSUBDOMAINS: return US"0"; |
| 379 | case DKIM_VERIFY_STATUS: return US"none"; |
| 380 | case DKIM_VERIFY_REASON: return US""; |
| 381 | default: return US""; |
| 382 | } |
| 383 | } |
| 384 | |
| 385 | |
| 386 | uschar *dkim_exim_sign(int dkim_fd, |
| 387 | uschar *dkim_private_key, |
| 388 | uschar *dkim_domain, |
| 389 | uschar *dkim_selector, |
| 390 | uschar *dkim_canon, |
| 391 | uschar *dkim_sign_headers) { |
| 392 | int sep = 0; |
| 393 | uschar *seen_items = NULL; |
| 394 | int seen_items_size = 0; |
| 395 | int seen_items_offset = 0; |
| 396 | uschar itembuf[256]; |
| 397 | uschar *dkim_canon_expanded; |
| 398 | uschar *dkim_sign_headers_expanded; |
| 399 | uschar *dkim_private_key_expanded; |
| 400 | pdkim_ctx *ctx = NULL; |
| 401 | uschar *rc = NULL; |
| 402 | uschar *sigbuf = NULL; |
| 403 | int sigsize = 0; |
| 404 | int sigptr = 0; |
| 405 | pdkim_signature *signature; |
| 406 | int pdkim_canon; |
| 407 | int pdkim_rc; |
| 408 | int sread; |
| 409 | char buf[4096]; |
| 410 | int save_errno = 0; |
| 411 | int old_pool = store_pool; |
| 412 | |
| 413 | store_pool = POOL_MAIN; |
| 414 | |
| 415 | dkim_domain = expand_string(dkim_domain); |
| 416 | if (dkim_domain == NULL) { |
| 417 | /* expansion error, do not send message. */ |
| 418 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " |
| 419 | "dkim_domain: %s", expand_string_message); |
| 420 | rc = NULL; |
| 421 | goto CLEANUP; |
| 422 | } |
| 423 | |
| 424 | /* Set $dkim_domain expansion variable to each unique domain in list. */ |
| 425 | while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, |
| 426 | itembuf, |
| 427 | sizeof(itembuf))) != NULL) { |
| 428 | if (!dkim_signing_domain || (dkim_signing_domain[0] == '\0')) continue; |
| 429 | /* Only sign once for each domain, no matter how often it |
| 430 | appears in the expanded list. */ |
| 431 | if (seen_items != NULL) { |
| 432 | uschar *seen_items_list = seen_items; |
| 433 | if (match_isinlist(dkim_signing_domain, |
| 434 | &seen_items_list,0,NULL,NULL,MCL_STRING,TRUE,NULL) == OK) |
| 435 | continue; |
| 436 | seen_items = string_append(seen_items,&seen_items_size,&seen_items_offset,1,":"); |
| 437 | } |
| 438 | seen_items = string_append(seen_items,&seen_items_size,&seen_items_offset,1,dkim_signing_domain); |
| 439 | seen_items[seen_items_offset] = '\0'; |
| 440 | |
| 441 | /* Set up $dkim_selector expansion variable. */ |
| 442 | dkim_signing_selector = expand_string(dkim_selector); |
| 443 | if (dkim_signing_selector == NULL) { |
| 444 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " |
| 445 | "dkim_selector: %s", expand_string_message); |
| 446 | rc = NULL; |
| 447 | goto CLEANUP; |
| 448 | } |
| 449 | |
| 450 | /* Get canonicalization to use */ |
| 451 | dkim_canon_expanded = expand_string(dkim_canon?dkim_canon:US"relaxed"); |
| 452 | if (dkim_canon_expanded == NULL) { |
| 453 | /* expansion error, do not send message. */ |
| 454 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " |
| 455 | "dkim_canon: %s", expand_string_message); |
| 456 | rc = NULL; |
| 457 | goto CLEANUP; |
| 458 | } |
| 459 | if (Ustrcmp(dkim_canon_expanded, "relaxed") == 0) |
| 460 | pdkim_canon = PDKIM_CANON_RELAXED; |
| 461 | else if (Ustrcmp(dkim_canon_expanded, "simple") == 0) |
| 462 | pdkim_canon = PDKIM_CANON_SIMPLE; |
| 463 | else { |
| 464 | log_write(0, LOG_MAIN, "DKIM: unknown canonicalization method '%s', defaulting to 'relaxed'.\n",dkim_canon_expanded); |
| 465 | pdkim_canon = PDKIM_CANON_RELAXED; |
| 466 | } |
| 467 | |
| 468 | if (dkim_sign_headers) { |
| 469 | dkim_sign_headers_expanded = expand_string(dkim_sign_headers); |
| 470 | if (dkim_sign_headers_expanded == NULL) { |
| 471 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " |
| 472 | "dkim_sign_headers: %s", expand_string_message); |
| 473 | rc = NULL; |
| 474 | goto CLEANUP; |
| 475 | } |
| 476 | } |
| 477 | else { |
| 478 | /* pass NULL, which means default header list */ |
| 479 | dkim_sign_headers_expanded = NULL; |
| 480 | } |
| 481 | |
| 482 | /* Get private key to use. */ |
| 483 | dkim_private_key_expanded = expand_string(dkim_private_key); |
| 484 | if (dkim_private_key_expanded == NULL) { |
| 485 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " |
| 486 | "dkim_private_key: %s", expand_string_message); |
| 487 | rc = NULL; |
| 488 | goto CLEANUP; |
| 489 | } |
| 490 | if ( (Ustrlen(dkim_private_key_expanded) == 0) || |
| 491 | (Ustrcmp(dkim_private_key_expanded,"0") == 0) || |
| 492 | (Ustrcmp(dkim_private_key_expanded,"false") == 0) ) { |
| 493 | /* don't sign, but no error */ |
| 494 | continue; |
| 495 | } |
| 496 | |
| 497 | if (dkim_private_key_expanded[0] == '/') { |
| 498 | int privkey_fd = 0; |
| 499 | /* Looks like a filename, load the private key. */ |
| 500 | memset(big_buffer,0,big_buffer_size); |
| 501 | privkey_fd = open(CS dkim_private_key_expanded,O_RDONLY); |
| 502 | if (privkey_fd < 0) { |
| 503 | log_write(0, LOG_MAIN|LOG_PANIC, "unable to open " |
| 504 | "private key file for reading: %s", dkim_private_key_expanded); |
| 505 | rc = NULL; |
| 506 | goto CLEANUP; |
| 507 | } |
| 508 | if (read(privkey_fd,big_buffer,(big_buffer_size-2)) < 0) { |
| 509 | log_write(0, LOG_MAIN|LOG_PANIC, "unable to read private key file: %s", |
| 510 | dkim_private_key_expanded); |
| 511 | rc = NULL; |
| 512 | goto CLEANUP; |
| 513 | } |
| 514 | (void)close(privkey_fd); |
| 515 | dkim_private_key_expanded = big_buffer; |
| 516 | } |
| 517 | |
| 518 | ctx = pdkim_init_sign(PDKIM_INPUT_SMTP, |
| 519 | (char *)dkim_signing_domain, |
| 520 | (char *)dkim_signing_selector, |
| 521 | (char *)dkim_private_key_expanded |
| 522 | ); |
| 523 | |
| 524 | pdkim_set_debug_stream(ctx,debug_file); |
| 525 | |
| 526 | pdkim_set_optional(ctx, |
| 527 | (char *)dkim_sign_headers_expanded, |
| 528 | NULL, |
| 529 | pdkim_canon, |
| 530 | pdkim_canon, |
| 531 | -1, |
| 532 | PDKIM_ALGO_RSA_SHA256, |
| 533 | 0, |
| 534 | 0); |
| 535 | |
| 536 | lseek(dkim_fd, 0, SEEK_SET); |
| 537 | while((sread = read(dkim_fd,&buf,4096)) > 0) { |
| 538 | if (pdkim_feed(ctx,buf,sread) != PDKIM_OK) { |
| 539 | rc = NULL; |
| 540 | goto CLEANUP; |
| 541 | } |
| 542 | } |
| 543 | /* Handle failed read above. */ |
| 544 | if (sread == -1) { |
| 545 | debug_printf("DKIM: Error reading -K file.\n"); |
| 546 | save_errno = errno; |
| 547 | rc = NULL; |
| 548 | goto CLEANUP; |
| 549 | } |
| 550 | |
| 551 | pdkim_rc = pdkim_feed_finish(ctx,&signature); |
| 552 | if (pdkim_rc != PDKIM_OK) { |
| 553 | log_write(0, LOG_MAIN|LOG_PANIC, "DKIM: signing failed (RC %d)", pdkim_rc); |
| 554 | rc = NULL; |
| 555 | goto CLEANUP; |
| 556 | } |
| 557 | |
| 558 | sigbuf = string_append(sigbuf, &sigsize, &sigptr, 2, |
| 559 | US signature->signature_header, |
| 560 | US"\r\n"); |
| 561 | |
| 562 | pdkim_free_ctx(ctx); |
| 563 | ctx = NULL; |
| 564 | } |
| 565 | |
| 566 | if (sigbuf != NULL) { |
| 567 | sigbuf[sigptr] = '\0'; |
| 568 | rc = sigbuf; |
| 569 | } else |
| 570 | rc = US""; |
| 571 | |
| 572 | CLEANUP: |
| 573 | if (ctx != NULL) |
| 574 | pdkim_free_ctx(ctx); |
| 575 | store_pool = old_pool; |
| 576 | errno = save_errno; |
| 577 | return rc; |
| 578 | } |
| 579 | |
| 580 | #endif |