Commit | Line | Data |
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80a47a2c TK |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
80fea873 | 5 | /* Copyright (c) University of Cambridge, 1995 - 2016 */ |
80a47a2c TK |
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 | ||
ca9cb170 | 17 | int dkim_verify_oldpool; |
1cfe5c1c | 18 | pdkim_ctx *dkim_verify_ctx = NULL; |
80a47a2c | 19 | pdkim_signature *dkim_signatures = NULL; |
1cfe5c1c | 20 | pdkim_signature *dkim_cur_sig = NULL; |
80a47a2c | 21 | |
1cfe5c1c JH |
22 | static int |
23 | dkim_exim_query_dns_txt(char *name, char *answer) | |
24 | { | |
25 | dns_answer dnsa; | |
26 | dns_scan dnss; | |
27 | dns_record *rr; | |
80a47a2c | 28 | |
1cfe5c1c JH |
29 | lookup_dnssec_authenticated = NULL; |
30 | if (dns_lookup(&dnsa, US name, T_TXT, NULL) != DNS_SUCCEED) | |
31 | return PDKIM_FAIL; | |
80a47a2c | 32 | |
1cfe5c1c | 33 | /* Search for TXT record */ |
80a47a2c | 34 | |
1cfe5c1c JH |
35 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); |
36 | rr; | |
37 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
38 | if (rr->type == T_TXT) | |
39 | { | |
80a47a2c TK |
40 | int rr_offset = 0; |
41 | int answer_offset = 0; | |
1cfe5c1c JH |
42 | |
43 | /* Copy record content to the answer buffer */ | |
44 | ||
45 | while (rr_offset < rr->size) | |
46 | { | |
47 | uschar len = rr->data[rr_offset++]; | |
48 | snprintf(answer + answer_offset, | |
49 | PDKIM_DNS_TXT_MAX_RECLEN - answer_offset, | |
50 | "%.*s", (int)len, (char *) (rr->data + rr_offset)); | |
51 | rr_offset += len; | |
52 | answer_offset += len; | |
53 | if (answer_offset >= PDKIM_DNS_TXT_MAX_RECLEN) | |
54 | return PDKIM_FAIL; | |
4263f395 | 55 | } |
1cfe5c1c | 56 | return PDKIM_OK; |
80a47a2c | 57 | } |
80a47a2c | 58 | |
1cfe5c1c | 59 | return PDKIM_FAIL; |
80a47a2c TK |
60 | } |
61 | ||
62 | ||
2592e6c0 JH |
63 | void |
64 | dkim_exim_init(void) | |
65 | { | |
66 | pdkim_init(); | |
67 | } | |
68 | ||
69 | ||
ca9cb170 | 70 | |
1cfe5c1c JH |
71 | void |
72 | dkim_exim_verify_init(void) | |
73 | { | |
ca9cb170 JH |
74 | /* There is a store-reset between header & body reception |
75 | so cannot use the main pool. Any allocs done by Exim | |
76 | memory-handling must use the perm pool. */ | |
77 | ||
78 | dkim_verify_oldpool = store_pool; | |
79 | store_pool = POOL_PERM; | |
80 | ||
1cfe5c1c | 81 | /* Free previous context if there is one */ |
80a47a2c | 82 | |
1cfe5c1c JH |
83 | if (dkim_verify_ctx) |
84 | pdkim_free_ctx(dkim_verify_ctx); | |
80a47a2c | 85 | |
1cfe5c1c | 86 | /* Create new context */ |
80a47a2c | 87 | |
0d04a285 | 88 | dkim_verify_ctx = pdkim_init_verify(&dkim_exim_query_dns_txt); |
3b957582 | 89 | dkim_collect_input = !!dkim_verify_ctx; |
ca9cb170 JH |
90 | |
91 | store_pool = dkim_verify_oldpool; | |
80a47a2c TK |
92 | } |
93 | ||
94 | ||
1cfe5c1c JH |
95 | void |
96 | dkim_exim_verify_feed(uschar * data, int len) | |
97 | { | |
ca9cb170 | 98 | store_pool = POOL_PERM; |
1cfe5c1c JH |
99 | if ( dkim_collect_input |
100 | && pdkim_feed(dkim_verify_ctx, (char *)data, len) != PDKIM_OK) | |
101 | dkim_collect_input = FALSE; | |
ca9cb170 | 102 | store_pool = dkim_verify_oldpool; |
80a47a2c TK |
103 | } |
104 | ||
105 | ||
1cfe5c1c JH |
106 | void |
107 | dkim_exim_verify_finish(void) | |
108 | { | |
109 | pdkim_signature *sig = NULL; | |
110 | int dkim_signers_size = 0; | |
111 | int dkim_signers_ptr = 0; | |
112 | dkim_signers = NULL; | |
113 | ||
ca9cb170 JH |
114 | store_pool = POOL_PERM; |
115 | ||
1cfe5c1c JH |
116 | /* Delete eventual previous signature chain */ |
117 | ||
118 | dkim_signatures = NULL; | |
119 | ||
120 | /* If we have arrived here with dkim_collect_input == FALSE, it | |
121 | means there was a processing error somewhere along the way. | |
122 | Log the incident and disable futher verification. */ | |
123 | ||
124 | if (!dkim_collect_input) | |
125 | { | |
126 | log_write(0, LOG_MAIN, | |
127 | "DKIM: Error while running this message through validation," | |
128 | " disabling signature verification."); | |
129 | dkim_disable_verify = TRUE; | |
ca9cb170 | 130 | goto out; |
1cfe5c1c | 131 | } |
80a47a2c | 132 | |
1cfe5c1c | 133 | dkim_collect_input = FALSE; |
80a47a2c | 134 | |
1cfe5c1c | 135 | /* Finish DKIM operation and fetch link to signatures chain */ |
80a47a2c | 136 | |
1cfe5c1c | 137 | if (pdkim_feed_finish(dkim_verify_ctx, &dkim_signatures) != PDKIM_OK) |
ca9cb170 | 138 | goto out; |
1cfe5c1c JH |
139 | |
140 | for (sig = dkim_signatures; sig; sig = sig->next) | |
141 | { | |
142 | int size = 0; | |
143 | int ptr = 0; | |
144 | ||
145 | /* Log a line for each signature */ | |
146 | ||
147 | uschar *logmsg = string_append(NULL, &size, &ptr, 5, | |
abe1010c | 148 | string_sprintf("d=%s s=%s c=%s/%s a=%s b=%d ", |
1cfe5c1c JH |
149 | sig->domain, |
150 | sig->selector, | |
151 | sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", | |
152 | sig->canon_body == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", | |
abe1010c | 153 | sig->algo == PDKIM_ALGO_RSA_SHA256 ? "rsa-sha256" : "rsa-sha1", |
2592e6c0 | 154 | sig->sigdata.len * 8 |
abe1010c | 155 | ), |
1cfe5c1c JH |
156 | |
157 | sig->identity ? string_sprintf("i=%s ", sig->identity) : US"", | |
158 | sig->created > 0 ? string_sprintf("t=%lu ", sig->created) : US"", | |
159 | sig->expires > 0 ? string_sprintf("x=%lu ", sig->expires) : US"", | |
160 | sig->bodylength > -1 ? string_sprintf("l=%lu ", sig->bodylength) : US"" | |
161 | ); | |
162 | ||
163 | switch (sig->verify_status) | |
164 | { | |
165 | case PDKIM_VERIFY_NONE: | |
166 | logmsg = string_append(logmsg, &size, &ptr, 1, "[not verified]"); | |
80a47a2c | 167 | break; |
1cfe5c1c JH |
168 | |
169 | case PDKIM_VERIFY_INVALID: | |
170 | logmsg = string_append(logmsg, &size, &ptr, 1, "[invalid - "); | |
171 | switch (sig->verify_ext_status) | |
172 | { | |
173 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: | |
174 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
175 | "public key record (currently?) unavailable]"); | |
176 | break; | |
177 | ||
178 | case PDKIM_VERIFY_INVALID_BUFFER_SIZE: | |
179 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
180 | "overlong public key record]"); | |
181 | break; | |
182 | ||
df3def24 JH |
183 | case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: |
184 | case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: | |
1cfe5c1c JH |
185 | logmsg = string_append(logmsg, &size, &ptr, 1, |
186 | "syntax error in public key record]"); | |
187 | break; | |
188 | ||
189 | default: | |
190 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
191 | "unspecified problem]"); | |
192 | } | |
80a47a2c | 193 | break; |
1cfe5c1c JH |
194 | |
195 | case PDKIM_VERIFY_FAIL: | |
196 | logmsg = | |
197 | string_append(logmsg, &size, &ptr, 1, "[verification failed - "); | |
198 | switch (sig->verify_ext_status) | |
199 | { | |
200 | case PDKIM_VERIFY_FAIL_BODY: | |
201 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
202 | "body hash mismatch (body probably modified in transit)]"); | |
203 | break; | |
204 | ||
205 | case PDKIM_VERIFY_FAIL_MESSAGE: | |
206 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
207 | "signature did not verify (headers probably modified in transit)]"); | |
208 | break; | |
209 | ||
210 | default: | |
211 | logmsg = string_append(logmsg, &size, &ptr, 1, "unspecified reason]"); | |
212 | } | |
80a47a2c | 213 | break; |
1cfe5c1c JH |
214 | |
215 | case PDKIM_VERIFY_PASS: | |
216 | logmsg = | |
217 | string_append(logmsg, &size, &ptr, 1, "[verification succeeded]"); | |
80a47a2c TK |
218 | break; |
219 | } | |
220 | ||
1cfe5c1c JH |
221 | logmsg[ptr] = '\0'; |
222 | log_write(0, LOG_MAIN, "DKIM: %s", logmsg); | |
80a47a2c | 223 | |
1cfe5c1c JH |
224 | /* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */ |
225 | ||
226 | dkim_signers = string_append(dkim_signers, | |
227 | &dkim_signers_size, | |
228 | &dkim_signers_ptr, 2, sig->domain, ":"); | |
229 | ||
230 | if (sig->identity) | |
9e5d6b55 | 231 | dkim_signers = string_append(dkim_signers, |
1cfe5c1c JH |
232 | &dkim_signers_size, |
233 | &dkim_signers_ptr, 2, sig->identity, ":"); | |
80a47a2c | 234 | |
1cfe5c1c | 235 | /* Process next signature */ |
80a47a2c TK |
236 | } |
237 | ||
1cfe5c1c JH |
238 | /* NULL-terminate and chop the last colon from the domain list */ |
239 | ||
240 | if (dkim_signers) | |
241 | { | |
242 | dkim_signers[dkim_signers_ptr] = '\0'; | |
243 | if (Ustrlen(dkim_signers) > 0) | |
244 | dkim_signers[Ustrlen(dkim_signers) - 1] = '\0'; | |
0d2b278d | 245 | } |
ca9cb170 JH |
246 | |
247 | out: | |
248 | store_pool = dkim_verify_oldpool; | |
80a47a2c TK |
249 | } |
250 | ||
251 | ||
1cfe5c1c JH |
252 | void |
253 | dkim_exim_acl_setup(uschar * id) | |
254 | { | |
255 | pdkim_signature * sig; | |
256 | uschar * cmp_val; | |
257 | ||
1cfe5c1c JH |
258 | dkim_cur_sig = NULL; |
259 | dkim_cur_signer = id; | |
260 | ||
261 | if (dkim_disable_verify || !id || !dkim_verify_ctx) | |
262 | return; | |
263 | ||
264 | /* Find signature to run ACL on */ | |
265 | ||
266 | for (sig = dkim_signatures; sig; sig = sig->next) | |
267 | if ( (cmp_val = Ustrchr(id, '@') != NULL ? US sig->identity : US sig->domain) | |
268 | && strcmpic(cmp_val, id) == 0 | |
269 | ) | |
270 | { | |
271 | dkim_cur_sig = sig; | |
272 | ||
273 | /* The "dkim_domain" and "dkim_selector" expansion variables have | |
274 | related globals, since they are used in the signing code too. | |
275 | Instead of inventing separate names for verification, we set | |
276 | them here. This is easy since a domain and selector is guaranteed | |
277 | to be in a signature. The other dkim_* expansion items are | |
278 | dynamically fetched from dkim_cur_sig at expansion time (see | |
279 | function below). */ | |
280 | ||
281 | dkim_signing_domain = US sig->domain; | |
282 | dkim_signing_selector = US sig->selector; | |
2592e6c0 | 283 | dkim_key_length = sig->sigdata.len * 8; |
1cfe5c1c | 284 | return; |
80a47a2c | 285 | } |
80a47a2c TK |
286 | } |
287 | ||
288 | ||
1cfe5c1c JH |
289 | static uschar * |
290 | dkim_exim_expand_defaults(int what) | |
291 | { | |
292 | switch (what) | |
293 | { | |
294 | case DKIM_ALGO: return US""; | |
295 | case DKIM_BODYLENGTH: return US"9999999999999"; | |
296 | case DKIM_CANON_BODY: return US""; | |
297 | case DKIM_CANON_HEADERS: return US""; | |
298 | case DKIM_COPIEDHEADERS: return US""; | |
299 | case DKIM_CREATED: return US"0"; | |
300 | case DKIM_EXPIRES: return US"9999999999999"; | |
301 | case DKIM_HEADERNAMES: return US""; | |
302 | case DKIM_IDENTITY: return US""; | |
303 | case DKIM_KEY_GRANULARITY: return US"*"; | |
304 | case DKIM_KEY_SRVTYPE: return US"*"; | |
305 | case DKIM_KEY_NOTES: return US""; | |
306 | case DKIM_KEY_TESTING: return US"0"; | |
307 | case DKIM_NOSUBDOMAINS: return US"0"; | |
308 | case DKIM_VERIFY_STATUS: return US"none"; | |
309 | case DKIM_VERIFY_REASON: return US""; | |
310 | default: return US""; | |
311 | } | |
312 | } | |
80a47a2c | 313 | |
80a47a2c | 314 | |
1cfe5c1c JH |
315 | uschar * |
316 | dkim_exim_expand_query(int what) | |
317 | { | |
318 | if (!dkim_verify_ctx || dkim_disable_verify || !dkim_cur_sig) | |
319 | return dkim_exim_expand_defaults(what); | |
320 | ||
321 | switch (what) | |
322 | { | |
323 | case DKIM_ALGO: | |
324 | switch (dkim_cur_sig->algo) | |
325 | { | |
326 | case PDKIM_ALGO_RSA_SHA1: return US"rsa-sha1"; | |
327 | case PDKIM_ALGO_RSA_SHA256: | |
328 | default: return US"rsa-sha256"; | |
da5dfc3a | 329 | } |
1cfe5c1c JH |
330 | |
331 | case DKIM_BODYLENGTH: | |
332 | return dkim_cur_sig->bodylength >= 0 | |
333 | ? string_sprintf(OFF_T_FMT, (LONGLONG_T) dkim_cur_sig->bodylength) | |
334 | : dkim_exim_expand_defaults(what); | |
335 | ||
336 | case DKIM_CANON_BODY: | |
337 | switch (dkim_cur_sig->canon_body) | |
338 | { | |
339 | case PDKIM_CANON_RELAXED: return US"relaxed"; | |
340 | case PDKIM_CANON_SIMPLE: | |
341 | default: return US"simple"; | |
80a47a2c | 342 | } |
1cfe5c1c JH |
343 | |
344 | case DKIM_CANON_HEADERS: | |
345 | switch (dkim_cur_sig->canon_headers) | |
346 | { | |
347 | case PDKIM_CANON_RELAXED: return US"relaxed"; | |
348 | case PDKIM_CANON_SIMPLE: | |
349 | default: return US"simple"; | |
350 | } | |
351 | ||
352 | case DKIM_COPIEDHEADERS: | |
353 | return dkim_cur_sig->copiedheaders | |
354 | ? US dkim_cur_sig->copiedheaders : dkim_exim_expand_defaults(what); | |
355 | ||
356 | case DKIM_CREATED: | |
357 | return dkim_cur_sig->created > 0 | |
358 | ? string_sprintf("%llu", dkim_cur_sig->created) | |
359 | : dkim_exim_expand_defaults(what); | |
360 | ||
361 | case DKIM_EXPIRES: | |
362 | return dkim_cur_sig->expires > 0 | |
363 | ? string_sprintf("%llu", dkim_cur_sig->expires) | |
364 | : dkim_exim_expand_defaults(what); | |
365 | ||
366 | case DKIM_HEADERNAMES: | |
367 | return dkim_cur_sig->headernames | |
2592e6c0 | 368 | ? dkim_cur_sig->headernames : dkim_exim_expand_defaults(what); |
1cfe5c1c JH |
369 | |
370 | case DKIM_IDENTITY: | |
371 | return dkim_cur_sig->identity | |
372 | ? US dkim_cur_sig->identity : dkim_exim_expand_defaults(what); | |
373 | ||
374 | case DKIM_KEY_GRANULARITY: | |
375 | return dkim_cur_sig->pubkey | |
376 | ? dkim_cur_sig->pubkey->granularity | |
377 | ? US dkim_cur_sig->pubkey->granularity | |
378 | : dkim_exim_expand_defaults(what) | |
379 | : dkim_exim_expand_defaults(what); | |
380 | ||
381 | case DKIM_KEY_SRVTYPE: | |
382 | return dkim_cur_sig->pubkey | |
383 | ? dkim_cur_sig->pubkey->srvtype | |
384 | ? US dkim_cur_sig->pubkey->srvtype | |
385 | : dkim_exim_expand_defaults(what) | |
386 | : dkim_exim_expand_defaults(what); | |
387 | ||
388 | case DKIM_KEY_NOTES: | |
389 | return dkim_cur_sig->pubkey | |
390 | ? dkim_cur_sig->pubkey->notes | |
391 | ? US dkim_cur_sig->pubkey->notes | |
392 | : dkim_exim_expand_defaults(what) | |
393 | : dkim_exim_expand_defaults(what); | |
394 | ||
395 | case DKIM_KEY_TESTING: | |
396 | return dkim_cur_sig->pubkey | |
397 | ? dkim_cur_sig->pubkey->testing | |
398 | ? US"1" | |
399 | : dkim_exim_expand_defaults(what) | |
400 | : dkim_exim_expand_defaults(what); | |
401 | ||
402 | case DKIM_NOSUBDOMAINS: | |
403 | return dkim_cur_sig->pubkey | |
404 | ? dkim_cur_sig->pubkey->no_subdomaining | |
405 | ? US"1" | |
406 | : dkim_exim_expand_defaults(what) | |
407 | : dkim_exim_expand_defaults(what); | |
408 | ||
409 | case DKIM_VERIFY_STATUS: | |
410 | switch (dkim_cur_sig->verify_status) | |
411 | { | |
412 | case PDKIM_VERIFY_INVALID: return US"invalid"; | |
413 | case PDKIM_VERIFY_FAIL: return US"fail"; | |
414 | case PDKIM_VERIFY_PASS: return US"pass"; | |
415 | case PDKIM_VERIFY_NONE: | |
416 | default: return US"none"; | |
80a47a2c | 417 | } |
80a47a2c | 418 | |
1cfe5c1c JH |
419 | case DKIM_VERIFY_REASON: |
420 | switch (dkim_cur_sig->verify_ext_status) | |
421 | { | |
422 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: | |
423 | return US"pubkey_unavailable"; | |
df3def24 JH |
424 | case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD:return US"pubkey_dns_syntax"; |
425 | case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return US"pubkey_der_syntax"; | |
1cfe5c1c JH |
426 | case PDKIM_VERIFY_FAIL_BODY: return US"bodyhash_mismatch"; |
427 | case PDKIM_VERIFY_FAIL_MESSAGE: return US"signature_incorrect"; | |
428 | } | |
80a47a2c | 429 | |
1cfe5c1c JH |
430 | default: |
431 | return US""; | |
80a47a2c TK |
432 | } |
433 | } | |
434 | ||
435 | ||
55414b25 | 436 | uschar * |
1cfe5c1c JH |
437 | dkim_exim_sign(int dkim_fd, uschar * dkim_private_key, |
438 | const uschar * dkim_domain, uschar * dkim_selector, | |
439 | uschar * dkim_canon, uschar * dkim_sign_headers) | |
55414b25 | 440 | { |
1cfe5c1c JH |
441 | int sep = 0; |
442 | uschar *seen_items = NULL; | |
443 | int seen_items_size = 0; | |
444 | int seen_items_offset = 0; | |
445 | uschar itembuf[256]; | |
446 | uschar *dkim_canon_expanded; | |
447 | uschar *dkim_sign_headers_expanded; | |
448 | uschar *dkim_private_key_expanded; | |
449 | pdkim_ctx *ctx = NULL; | |
450 | uschar *rc = NULL; | |
451 | uschar *sigbuf = NULL; | |
452 | int sigsize = 0; | |
453 | int sigptr = 0; | |
454 | pdkim_signature *signature; | |
455 | int pdkim_canon; | |
456 | int pdkim_rc; | |
457 | int sread; | |
458 | char buf[4096]; | |
459 | int save_errno = 0; | |
460 | int old_pool = store_pool; | |
461 | ||
462 | store_pool = POOL_MAIN; | |
463 | ||
464 | if (!(dkim_domain = expand_cstring(dkim_domain))) | |
465 | { | |
466 | /* expansion error, do not send message. */ | |
467 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
468 | "dkim_domain: %s", expand_string_message); | |
469 | rc = NULL; | |
470 | goto CLEANUP; | |
471 | } | |
472 | ||
473 | /* Set $dkim_domain expansion variable to each unique domain in list. */ | |
474 | ||
475 | while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, | |
476 | itembuf, sizeof(itembuf)))) | |
477 | { | |
478 | if (!dkim_signing_domain || dkim_signing_domain[0] == '\0') | |
479 | continue; | |
480 | ||
481 | /* Only sign once for each domain, no matter how often it | |
482 | appears in the expanded list. */ | |
483 | ||
484 | if (seen_items) | |
485 | { | |
486 | const uschar *seen_items_list = seen_items; | |
487 | if (match_isinlist(dkim_signing_domain, | |
488 | &seen_items_list, 0, NULL, NULL, MCL_STRING, TRUE, | |
489 | NULL) == OK) | |
490 | continue; | |
491 | ||
492 | seen_items = | |
493 | string_append(seen_items, &seen_items_size, &seen_items_offset, 1, ":"); | |
494 | } | |
495 | ||
496 | seen_items = | |
497 | string_append(seen_items, &seen_items_size, &seen_items_offset, 1, | |
498 | dkim_signing_domain); | |
499 | seen_items[seen_items_offset] = '\0'; | |
500 | ||
501 | /* Set up $dkim_selector expansion variable. */ | |
502 | ||
503 | if (!(dkim_signing_selector = expand_string(dkim_selector))) | |
504 | { | |
505 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
506 | "dkim_selector: %s", expand_string_message); | |
507 | rc = NULL; | |
508 | goto CLEANUP; | |
509 | } | |
510 | ||
511 | /* Get canonicalization to use */ | |
512 | ||
513 | dkim_canon_expanded = dkim_canon ? expand_string(dkim_canon) : US"relaxed"; | |
514 | if (!dkim_canon_expanded) | |
515 | { | |
80a47a2c | 516 | /* expansion error, do not send message. */ |
1cfe5c1c JH |
517 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " |
518 | "dkim_canon: %s", expand_string_message); | |
80a47a2c TK |
519 | rc = NULL; |
520 | goto CLEANUP; | |
1cfe5c1c | 521 | } |
80a47a2c | 522 | |
1cfe5c1c JH |
523 | if (Ustrcmp(dkim_canon_expanded, "relaxed") == 0) |
524 | pdkim_canon = PDKIM_CANON_RELAXED; | |
525 | else if (Ustrcmp(dkim_canon_expanded, "simple") == 0) | |
526 | pdkim_canon = PDKIM_CANON_SIMPLE; | |
527 | else | |
528 | { | |
529 | log_write(0, LOG_MAIN, | |
530 | "DKIM: unknown canonicalization method '%s', defaulting to 'relaxed'.\n", | |
531 | dkim_canon_expanded); | |
532 | pdkim_canon = PDKIM_CANON_RELAXED; | |
a8e1eeba | 533 | } |
1cfe5c1c JH |
534 | |
535 | dkim_sign_headers_expanded = NULL; | |
536 | if (dkim_sign_headers) | |
537 | if (!(dkim_sign_headers_expanded = expand_string(dkim_sign_headers))) | |
538 | { | |
539 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
540 | "dkim_sign_headers: %s", expand_string_message); | |
a8e1eeba MH |
541 | rc = NULL; |
542 | goto CLEANUP; | |
1cfe5c1c JH |
543 | } |
544 | /* else pass NULL, which means default header list */ | |
545 | ||
546 | /* Get private key to use. */ | |
547 | ||
548 | if (!(dkim_private_key_expanded = expand_string(dkim_private_key))) | |
549 | { | |
550 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
551 | "dkim_private_key: %s", expand_string_message); | |
552 | rc = NULL; | |
553 | goto CLEANUP; | |
a8e1eeba | 554 | } |
80a47a2c | 555 | |
1cfe5c1c JH |
556 | if ( Ustrlen(dkim_private_key_expanded) == 0 |
557 | || Ustrcmp(dkim_private_key_expanded, "0") == 0 | |
558 | || Ustrcmp(dkim_private_key_expanded, "false") == 0 | |
559 | ) | |
560 | continue; /* don't sign, but no error */ | |
561 | ||
562 | if (dkim_private_key_expanded[0] == '/') | |
563 | { | |
564 | int privkey_fd = 0; | |
565 | ||
566 | /* Looks like a filename, load the private key. */ | |
567 | ||
568 | memset(big_buffer, 0, big_buffer_size); | |
569 | privkey_fd = open(CS dkim_private_key_expanded, O_RDONLY); | |
570 | if (privkey_fd < 0) | |
571 | { | |
572 | log_write(0, LOG_MAIN | LOG_PANIC, "unable to open " | |
573 | "private key file for reading: %s", | |
574 | dkim_private_key_expanded); | |
80a47a2c TK |
575 | rc = NULL; |
576 | goto CLEANUP; | |
db4d0902 | 577 | } |
80a47a2c | 578 | |
1cfe5c1c JH |
579 | if (read(privkey_fd, big_buffer, big_buffer_size - 2) < 0) |
580 | { | |
581 | log_write(0, LOG_MAIN|LOG_PANIC, "unable to read private key file: %s", | |
582 | dkim_private_key_expanded); | |
cf745305 TK |
583 | rc = NULL; |
584 | goto CLEANUP; | |
1ac6b2e7 | 585 | } |
80a47a2c | 586 | |
1cfe5c1c JH |
587 | (void) close(privkey_fd); |
588 | dkim_private_key_expanded = big_buffer; | |
a8e1eeba | 589 | } |
1cfe5c1c | 590 | |
0d04a285 | 591 | ctx = pdkim_init_sign( (char *) dkim_signing_domain, |
1cfe5c1c | 592 | (char *) dkim_signing_selector, |
f444c2c7 JH |
593 | (char *) dkim_private_key_expanded, |
594 | PDKIM_ALGO_RSA_SHA256); | |
1cfe5c1c JH |
595 | pdkim_set_optional(ctx, |
596 | (char *) dkim_sign_headers_expanded, | |
597 | NULL, | |
598 | pdkim_canon, | |
f444c2c7 | 599 | pdkim_canon, -1, 0, 0); |
1cfe5c1c JH |
600 | |
601 | lseek(dkim_fd, 0, SEEK_SET); | |
602 | ||
603 | while ((sread = read(dkim_fd, &buf, 4096)) > 0) | |
604 | if (pdkim_feed(ctx, buf, sread) != PDKIM_OK) | |
605 | { | |
80a47a2c TK |
606 | rc = NULL; |
607 | goto CLEANUP; | |
1cfe5c1c JH |
608 | } |
609 | ||
610 | /* Handle failed read above. */ | |
611 | if (sread == -1) | |
612 | { | |
613 | debug_printf("DKIM: Error reading -K file.\n"); | |
614 | save_errno = errno; | |
615 | rc = NULL; | |
616 | goto CLEANUP; | |
80a47a2c | 617 | } |
80a47a2c | 618 | |
1cfe5c1c JH |
619 | if ((pdkim_rc = pdkim_feed_finish(ctx, &signature)) != PDKIM_OK) |
620 | { | |
621 | log_write(0, LOG_MAIN|LOG_PANIC, "DKIM: signing failed (RC %d)", pdkim_rc); | |
622 | rc = NULL; | |
623 | goto CLEANUP; | |
a8e1eeba | 624 | } |
80a47a2c | 625 | |
1cfe5c1c JH |
626 | sigbuf = string_append(sigbuf, &sigsize, &sigptr, 2, |
627 | US signature->signature_header, US"\r\n"); | |
80a47a2c | 628 | |
1cfe5c1c JH |
629 | pdkim_free_ctx(ctx); |
630 | ctx = NULL; | |
80a47a2c | 631 | } |
a8e1eeba | 632 | |
1cfe5c1c JH |
633 | if (sigbuf) |
634 | { | |
635 | sigbuf[sigptr] = '\0'; | |
636 | rc = sigbuf; | |
637 | } | |
638 | else | |
639 | rc = US""; | |
640 | ||
641 | CLEANUP: | |
642 | if (ctx) | |
643 | pdkim_free_ctx(ctx); | |
644 | store_pool = old_pool; | |
645 | errno = save_errno; | |
646 | return rc; | |
93f2d376 | 647 | } |
80a47a2c TK |
648 | |
649 | #endif |