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