Commit | Line | Data |
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80a47a2c TK |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
3386088d | 5 | /* Copyright (c) University of Cambridge, 1995 - 2015 */ |
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 | ||
1cfe5c1c JH |
62 | void |
63 | dkim_exim_verify_init(void) | |
64 | { | |
65 | /* Free previous context if there is one */ | |
80a47a2c | 66 | |
1cfe5c1c JH |
67 | if (dkim_verify_ctx) |
68 | pdkim_free_ctx(dkim_verify_ctx); | |
80a47a2c | 69 | |
1cfe5c1c | 70 | /* Create new context */ |
80a47a2c | 71 | |
0d04a285 | 72 | dkim_verify_ctx = pdkim_init_verify(&dkim_exim_query_dns_txt); |
3b957582 | 73 | dkim_collect_input = !!dkim_verify_ctx; |
80a47a2c TK |
74 | } |
75 | ||
76 | ||
1cfe5c1c JH |
77 | void |
78 | dkim_exim_verify_feed(uschar * data, int len) | |
79 | { | |
80 | if ( dkim_collect_input | |
81 | && pdkim_feed(dkim_verify_ctx, (char *)data, len) != PDKIM_OK) | |
82 | dkim_collect_input = FALSE; | |
80a47a2c TK |
83 | } |
84 | ||
85 | ||
1cfe5c1c JH |
86 | void |
87 | dkim_exim_verify_finish(void) | |
88 | { | |
89 | pdkim_signature *sig = NULL; | |
90 | int dkim_signers_size = 0; | |
91 | int dkim_signers_ptr = 0; | |
92 | dkim_signers = NULL; | |
93 | ||
94 | /* Delete eventual previous signature chain */ | |
95 | ||
96 | dkim_signatures = NULL; | |
97 | ||
98 | /* If we have arrived here with dkim_collect_input == FALSE, it | |
99 | means there was a processing error somewhere along the way. | |
100 | Log the incident and disable futher verification. */ | |
101 | ||
102 | if (!dkim_collect_input) | |
103 | { | |
104 | log_write(0, LOG_MAIN, | |
105 | "DKIM: Error while running this message through validation," | |
106 | " disabling signature verification."); | |
107 | dkim_disable_verify = TRUE; | |
108 | return; | |
109 | } | |
80a47a2c | 110 | |
1cfe5c1c | 111 | dkim_collect_input = FALSE; |
80a47a2c | 112 | |
1cfe5c1c | 113 | /* Finish DKIM operation and fetch link to signatures chain */ |
80a47a2c | 114 | |
1cfe5c1c JH |
115 | if (pdkim_feed_finish(dkim_verify_ctx, &dkim_signatures) != PDKIM_OK) |
116 | return; | |
117 | ||
118 | for (sig = dkim_signatures; sig; sig = sig->next) | |
119 | { | |
120 | int size = 0; | |
121 | int ptr = 0; | |
122 | ||
123 | /* Log a line for each signature */ | |
124 | ||
125 | uschar *logmsg = string_append(NULL, &size, &ptr, 5, | |
abe1010c | 126 | string_sprintf("d=%s s=%s c=%s/%s a=%s b=%d ", |
1cfe5c1c JH |
127 | sig->domain, |
128 | sig->selector, | |
129 | sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", | |
130 | sig->canon_body == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", | |
abe1010c JH |
131 | sig->algo == PDKIM_ALGO_RSA_SHA256 ? "rsa-sha256" : "rsa-sha1", |
132 | sig->sigdata_len * 8 | |
133 | ), | |
1cfe5c1c JH |
134 | |
135 | sig->identity ? string_sprintf("i=%s ", sig->identity) : US"", | |
136 | sig->created > 0 ? string_sprintf("t=%lu ", sig->created) : US"", | |
137 | sig->expires > 0 ? string_sprintf("x=%lu ", sig->expires) : US"", | |
138 | sig->bodylength > -1 ? string_sprintf("l=%lu ", sig->bodylength) : US"" | |
139 | ); | |
140 | ||
141 | switch (sig->verify_status) | |
142 | { | |
143 | case PDKIM_VERIFY_NONE: | |
144 | logmsg = string_append(logmsg, &size, &ptr, 1, "[not verified]"); | |
80a47a2c | 145 | break; |
1cfe5c1c JH |
146 | |
147 | case PDKIM_VERIFY_INVALID: | |
148 | logmsg = string_append(logmsg, &size, &ptr, 1, "[invalid - "); | |
149 | switch (sig->verify_ext_status) | |
150 | { | |
151 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: | |
152 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
153 | "public key record (currently?) unavailable]"); | |
154 | break; | |
155 | ||
156 | case PDKIM_VERIFY_INVALID_BUFFER_SIZE: | |
157 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
158 | "overlong public key record]"); | |
159 | break; | |
160 | ||
df3def24 JH |
161 | case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: |
162 | case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: | |
1cfe5c1c JH |
163 | logmsg = string_append(logmsg, &size, &ptr, 1, |
164 | "syntax error in public key record]"); | |
165 | break; | |
166 | ||
167 | default: | |
168 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
169 | "unspecified problem]"); | |
170 | } | |
80a47a2c | 171 | break; |
1cfe5c1c JH |
172 | |
173 | case PDKIM_VERIFY_FAIL: | |
174 | logmsg = | |
175 | string_append(logmsg, &size, &ptr, 1, "[verification failed - "); | |
176 | switch (sig->verify_ext_status) | |
177 | { | |
178 | case PDKIM_VERIFY_FAIL_BODY: | |
179 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
180 | "body hash mismatch (body probably modified in transit)]"); | |
181 | break; | |
182 | ||
183 | case PDKIM_VERIFY_FAIL_MESSAGE: | |
184 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
185 | "signature did not verify (headers probably modified in transit)]"); | |
186 | break; | |
187 | ||
188 | default: | |
189 | logmsg = string_append(logmsg, &size, &ptr, 1, "unspecified reason]"); | |
190 | } | |
80a47a2c | 191 | break; |
1cfe5c1c JH |
192 | |
193 | case PDKIM_VERIFY_PASS: | |
194 | logmsg = | |
195 | string_append(logmsg, &size, &ptr, 1, "[verification succeeded]"); | |
80a47a2c TK |
196 | break; |
197 | } | |
198 | ||
1cfe5c1c JH |
199 | logmsg[ptr] = '\0'; |
200 | log_write(0, LOG_MAIN, "DKIM: %s", logmsg); | |
80a47a2c | 201 | |
1cfe5c1c JH |
202 | /* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */ |
203 | ||
204 | dkim_signers = string_append(dkim_signers, | |
205 | &dkim_signers_size, | |
206 | &dkim_signers_ptr, 2, sig->domain, ":"); | |
207 | ||
208 | if (sig->identity) | |
9e5d6b55 | 209 | dkim_signers = string_append(dkim_signers, |
1cfe5c1c JH |
210 | &dkim_signers_size, |
211 | &dkim_signers_ptr, 2, sig->identity, ":"); | |
80a47a2c | 212 | |
1cfe5c1c | 213 | /* Process next signature */ |
80a47a2c TK |
214 | } |
215 | ||
1cfe5c1c JH |
216 | /* NULL-terminate and chop the last colon from the domain list */ |
217 | ||
218 | if (dkim_signers) | |
219 | { | |
220 | dkim_signers[dkim_signers_ptr] = '\0'; | |
221 | if (Ustrlen(dkim_signers) > 0) | |
222 | dkim_signers[Ustrlen(dkim_signers) - 1] = '\0'; | |
0d2b278d | 223 | } |
80a47a2c TK |
224 | } |
225 | ||
226 | ||
1cfe5c1c JH |
227 | void |
228 | dkim_exim_acl_setup(uschar * id) | |
229 | { | |
230 | pdkim_signature * sig; | |
231 | uschar * cmp_val; | |
232 | ||
1cfe5c1c JH |
233 | dkim_cur_sig = NULL; |
234 | dkim_cur_signer = id; | |
235 | ||
236 | if (dkim_disable_verify || !id || !dkim_verify_ctx) | |
237 | return; | |
238 | ||
239 | /* Find signature to run ACL on */ | |
240 | ||
241 | for (sig = dkim_signatures; sig; sig = sig->next) | |
242 | if ( (cmp_val = Ustrchr(id, '@') != NULL ? US sig->identity : US sig->domain) | |
243 | && strcmpic(cmp_val, id) == 0 | |
244 | ) | |
245 | { | |
246 | dkim_cur_sig = sig; | |
247 | ||
248 | /* The "dkim_domain" and "dkim_selector" expansion variables have | |
249 | related globals, since they are used in the signing code too. | |
250 | Instead of inventing separate names for verification, we set | |
251 | them here. This is easy since a domain and selector is guaranteed | |
252 | to be in a signature. The other dkim_* expansion items are | |
253 | dynamically fetched from dkim_cur_sig at expansion time (see | |
254 | function below). */ | |
255 | ||
256 | dkim_signing_domain = US sig->domain; | |
257 | dkim_signing_selector = US sig->selector; | |
abe1010c | 258 | dkim_key_length = sig->sigdata_len * 8; |
1cfe5c1c | 259 | return; |
80a47a2c | 260 | } |
80a47a2c TK |
261 | } |
262 | ||
263 | ||
1cfe5c1c JH |
264 | static uschar * |
265 | dkim_exim_expand_defaults(int what) | |
266 | { | |
267 | switch (what) | |
268 | { | |
269 | case DKIM_ALGO: return US""; | |
270 | case DKIM_BODYLENGTH: return US"9999999999999"; | |
271 | case DKIM_CANON_BODY: return US""; | |
272 | case DKIM_CANON_HEADERS: return US""; | |
273 | case DKIM_COPIEDHEADERS: return US""; | |
274 | case DKIM_CREATED: return US"0"; | |
275 | case DKIM_EXPIRES: return US"9999999999999"; | |
276 | case DKIM_HEADERNAMES: return US""; | |
277 | case DKIM_IDENTITY: return US""; | |
278 | case DKIM_KEY_GRANULARITY: return US"*"; | |
279 | case DKIM_KEY_SRVTYPE: return US"*"; | |
280 | case DKIM_KEY_NOTES: return US""; | |
281 | case DKIM_KEY_TESTING: return US"0"; | |
282 | case DKIM_NOSUBDOMAINS: return US"0"; | |
283 | case DKIM_VERIFY_STATUS: return US"none"; | |
284 | case DKIM_VERIFY_REASON: return US""; | |
285 | default: return US""; | |
286 | } | |
287 | } | |
80a47a2c | 288 | |
80a47a2c | 289 | |
1cfe5c1c JH |
290 | uschar * |
291 | dkim_exim_expand_query(int what) | |
292 | { | |
293 | if (!dkim_verify_ctx || dkim_disable_verify || !dkim_cur_sig) | |
294 | return dkim_exim_expand_defaults(what); | |
295 | ||
296 | switch (what) | |
297 | { | |
298 | case DKIM_ALGO: | |
299 | switch (dkim_cur_sig->algo) | |
300 | { | |
301 | case PDKIM_ALGO_RSA_SHA1: return US"rsa-sha1"; | |
302 | case PDKIM_ALGO_RSA_SHA256: | |
303 | default: return US"rsa-sha256"; | |
da5dfc3a | 304 | } |
1cfe5c1c JH |
305 | |
306 | case DKIM_BODYLENGTH: | |
307 | return dkim_cur_sig->bodylength >= 0 | |
308 | ? string_sprintf(OFF_T_FMT, (LONGLONG_T) dkim_cur_sig->bodylength) | |
309 | : dkim_exim_expand_defaults(what); | |
310 | ||
311 | case DKIM_CANON_BODY: | |
312 | switch (dkim_cur_sig->canon_body) | |
313 | { | |
314 | case PDKIM_CANON_RELAXED: return US"relaxed"; | |
315 | case PDKIM_CANON_SIMPLE: | |
316 | default: return US"simple"; | |
80a47a2c | 317 | } |
1cfe5c1c JH |
318 | |
319 | case DKIM_CANON_HEADERS: | |
320 | switch (dkim_cur_sig->canon_headers) | |
321 | { | |
322 | case PDKIM_CANON_RELAXED: return US"relaxed"; | |
323 | case PDKIM_CANON_SIMPLE: | |
324 | default: return US"simple"; | |
325 | } | |
326 | ||
327 | case DKIM_COPIEDHEADERS: | |
328 | return dkim_cur_sig->copiedheaders | |
329 | ? US dkim_cur_sig->copiedheaders : dkim_exim_expand_defaults(what); | |
330 | ||
331 | case DKIM_CREATED: | |
332 | return dkim_cur_sig->created > 0 | |
333 | ? string_sprintf("%llu", dkim_cur_sig->created) | |
334 | : dkim_exim_expand_defaults(what); | |
335 | ||
336 | case DKIM_EXPIRES: | |
337 | return dkim_cur_sig->expires > 0 | |
338 | ? string_sprintf("%llu", dkim_cur_sig->expires) | |
339 | : dkim_exim_expand_defaults(what); | |
340 | ||
341 | case DKIM_HEADERNAMES: | |
342 | return dkim_cur_sig->headernames | |
343 | ? US dkim_cur_sig->headernames : dkim_exim_expand_defaults(what); | |
344 | ||
345 | case DKIM_IDENTITY: | |
346 | return dkim_cur_sig->identity | |
347 | ? US dkim_cur_sig->identity : dkim_exim_expand_defaults(what); | |
348 | ||
349 | case DKIM_KEY_GRANULARITY: | |
350 | return dkim_cur_sig->pubkey | |
351 | ? dkim_cur_sig->pubkey->granularity | |
352 | ? US dkim_cur_sig->pubkey->granularity | |
353 | : dkim_exim_expand_defaults(what) | |
354 | : dkim_exim_expand_defaults(what); | |
355 | ||
356 | case DKIM_KEY_SRVTYPE: | |
357 | return dkim_cur_sig->pubkey | |
358 | ? dkim_cur_sig->pubkey->srvtype | |
359 | ? US dkim_cur_sig->pubkey->srvtype | |
360 | : dkim_exim_expand_defaults(what) | |
361 | : dkim_exim_expand_defaults(what); | |
362 | ||
363 | case DKIM_KEY_NOTES: | |
364 | return dkim_cur_sig->pubkey | |
365 | ? dkim_cur_sig->pubkey->notes | |
366 | ? US dkim_cur_sig->pubkey->notes | |
367 | : dkim_exim_expand_defaults(what) | |
368 | : dkim_exim_expand_defaults(what); | |
369 | ||
370 | case DKIM_KEY_TESTING: | |
371 | return dkim_cur_sig->pubkey | |
372 | ? dkim_cur_sig->pubkey->testing | |
373 | ? US"1" | |
374 | : dkim_exim_expand_defaults(what) | |
375 | : dkim_exim_expand_defaults(what); | |
376 | ||
377 | case DKIM_NOSUBDOMAINS: | |
378 | return dkim_cur_sig->pubkey | |
379 | ? dkim_cur_sig->pubkey->no_subdomaining | |
380 | ? US"1" | |
381 | : dkim_exim_expand_defaults(what) | |
382 | : dkim_exim_expand_defaults(what); | |
383 | ||
384 | case DKIM_VERIFY_STATUS: | |
385 | switch (dkim_cur_sig->verify_status) | |
386 | { | |
387 | case PDKIM_VERIFY_INVALID: return US"invalid"; | |
388 | case PDKIM_VERIFY_FAIL: return US"fail"; | |
389 | case PDKIM_VERIFY_PASS: return US"pass"; | |
390 | case PDKIM_VERIFY_NONE: | |
391 | default: return US"none"; | |
80a47a2c | 392 | } |
80a47a2c | 393 | |
1cfe5c1c JH |
394 | case DKIM_VERIFY_REASON: |
395 | switch (dkim_cur_sig->verify_ext_status) | |
396 | { | |
397 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: | |
398 | return US"pubkey_unavailable"; | |
df3def24 JH |
399 | case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD:return US"pubkey_dns_syntax"; |
400 | case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return US"pubkey_der_syntax"; | |
1cfe5c1c JH |
401 | case PDKIM_VERIFY_FAIL_BODY: return US"bodyhash_mismatch"; |
402 | case PDKIM_VERIFY_FAIL_MESSAGE: return US"signature_incorrect"; | |
403 | } | |
80a47a2c | 404 | |
1cfe5c1c JH |
405 | default: |
406 | return US""; | |
80a47a2c TK |
407 | } |
408 | } | |
409 | ||
410 | ||
55414b25 | 411 | uschar * |
1cfe5c1c JH |
412 | dkim_exim_sign(int dkim_fd, uschar * dkim_private_key, |
413 | const uschar * dkim_domain, uschar * dkim_selector, | |
414 | uschar * dkim_canon, uschar * dkim_sign_headers) | |
55414b25 | 415 | { |
1cfe5c1c JH |
416 | int sep = 0; |
417 | uschar *seen_items = NULL; | |
418 | int seen_items_size = 0; | |
419 | int seen_items_offset = 0; | |
420 | uschar itembuf[256]; | |
421 | uschar *dkim_canon_expanded; | |
422 | uschar *dkim_sign_headers_expanded; | |
423 | uschar *dkim_private_key_expanded; | |
424 | pdkim_ctx *ctx = NULL; | |
425 | uschar *rc = NULL; | |
426 | uschar *sigbuf = NULL; | |
427 | int sigsize = 0; | |
428 | int sigptr = 0; | |
429 | pdkim_signature *signature; | |
430 | int pdkim_canon; | |
431 | int pdkim_rc; | |
432 | int sread; | |
433 | char buf[4096]; | |
434 | int save_errno = 0; | |
435 | int old_pool = store_pool; | |
436 | ||
437 | store_pool = POOL_MAIN; | |
438 | ||
439 | if (!(dkim_domain = expand_cstring(dkim_domain))) | |
440 | { | |
441 | /* expansion error, do not send message. */ | |
442 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
443 | "dkim_domain: %s", expand_string_message); | |
444 | rc = NULL; | |
445 | goto CLEANUP; | |
446 | } | |
447 | ||
448 | /* Set $dkim_domain expansion variable to each unique domain in list. */ | |
449 | ||
450 | while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, | |
451 | itembuf, sizeof(itembuf)))) | |
452 | { | |
453 | if (!dkim_signing_domain || dkim_signing_domain[0] == '\0') | |
454 | continue; | |
455 | ||
456 | /* Only sign once for each domain, no matter how often it | |
457 | appears in the expanded list. */ | |
458 | ||
459 | if (seen_items) | |
460 | { | |
461 | const uschar *seen_items_list = seen_items; | |
462 | if (match_isinlist(dkim_signing_domain, | |
463 | &seen_items_list, 0, NULL, NULL, MCL_STRING, TRUE, | |
464 | NULL) == OK) | |
465 | continue; | |
466 | ||
467 | seen_items = | |
468 | string_append(seen_items, &seen_items_size, &seen_items_offset, 1, ":"); | |
469 | } | |
470 | ||
471 | seen_items = | |
472 | string_append(seen_items, &seen_items_size, &seen_items_offset, 1, | |
473 | dkim_signing_domain); | |
474 | seen_items[seen_items_offset] = '\0'; | |
475 | ||
476 | /* Set up $dkim_selector expansion variable. */ | |
477 | ||
478 | if (!(dkim_signing_selector = expand_string(dkim_selector))) | |
479 | { | |
480 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
481 | "dkim_selector: %s", expand_string_message); | |
482 | rc = NULL; | |
483 | goto CLEANUP; | |
484 | } | |
485 | ||
486 | /* Get canonicalization to use */ | |
487 | ||
488 | dkim_canon_expanded = dkim_canon ? expand_string(dkim_canon) : US"relaxed"; | |
489 | if (!dkim_canon_expanded) | |
490 | { | |
80a47a2c | 491 | /* expansion error, do not send message. */ |
1cfe5c1c JH |
492 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " |
493 | "dkim_canon: %s", expand_string_message); | |
80a47a2c TK |
494 | rc = NULL; |
495 | goto CLEANUP; | |
1cfe5c1c | 496 | } |
80a47a2c | 497 | |
1cfe5c1c JH |
498 | if (Ustrcmp(dkim_canon_expanded, "relaxed") == 0) |
499 | pdkim_canon = PDKIM_CANON_RELAXED; | |
500 | else if (Ustrcmp(dkim_canon_expanded, "simple") == 0) | |
501 | pdkim_canon = PDKIM_CANON_SIMPLE; | |
502 | else | |
503 | { | |
504 | log_write(0, LOG_MAIN, | |
505 | "DKIM: unknown canonicalization method '%s', defaulting to 'relaxed'.\n", | |
506 | dkim_canon_expanded); | |
507 | pdkim_canon = PDKIM_CANON_RELAXED; | |
a8e1eeba | 508 | } |
1cfe5c1c JH |
509 | |
510 | dkim_sign_headers_expanded = NULL; | |
511 | if (dkim_sign_headers) | |
512 | if (!(dkim_sign_headers_expanded = expand_string(dkim_sign_headers))) | |
513 | { | |
514 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
515 | "dkim_sign_headers: %s", expand_string_message); | |
a8e1eeba MH |
516 | rc = NULL; |
517 | goto CLEANUP; | |
1cfe5c1c JH |
518 | } |
519 | /* else pass NULL, which means default header list */ | |
520 | ||
521 | /* Get private key to use. */ | |
522 | ||
523 | if (!(dkim_private_key_expanded = expand_string(dkim_private_key))) | |
524 | { | |
525 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
526 | "dkim_private_key: %s", expand_string_message); | |
527 | rc = NULL; | |
528 | goto CLEANUP; | |
a8e1eeba | 529 | } |
80a47a2c | 530 | |
1cfe5c1c JH |
531 | if ( Ustrlen(dkim_private_key_expanded) == 0 |
532 | || Ustrcmp(dkim_private_key_expanded, "0") == 0 | |
533 | || Ustrcmp(dkim_private_key_expanded, "false") == 0 | |
534 | ) | |
535 | continue; /* don't sign, but no error */ | |
536 | ||
537 | if (dkim_private_key_expanded[0] == '/') | |
538 | { | |
539 | int privkey_fd = 0; | |
540 | ||
541 | /* Looks like a filename, load the private key. */ | |
542 | ||
543 | memset(big_buffer, 0, big_buffer_size); | |
544 | privkey_fd = open(CS dkim_private_key_expanded, O_RDONLY); | |
545 | if (privkey_fd < 0) | |
546 | { | |
547 | log_write(0, LOG_MAIN | LOG_PANIC, "unable to open " | |
548 | "private key file for reading: %s", | |
549 | dkim_private_key_expanded); | |
80a47a2c TK |
550 | rc = NULL; |
551 | goto CLEANUP; | |
db4d0902 | 552 | } |
80a47a2c | 553 | |
1cfe5c1c JH |
554 | if (read(privkey_fd, big_buffer, big_buffer_size - 2) < 0) |
555 | { | |
556 | log_write(0, LOG_MAIN|LOG_PANIC, "unable to read private key file: %s", | |
557 | dkim_private_key_expanded); | |
cf745305 TK |
558 | rc = NULL; |
559 | goto CLEANUP; | |
1ac6b2e7 | 560 | } |
80a47a2c | 561 | |
1cfe5c1c JH |
562 | (void) close(privkey_fd); |
563 | dkim_private_key_expanded = big_buffer; | |
a8e1eeba | 564 | } |
1cfe5c1c | 565 | |
0d04a285 | 566 | ctx = pdkim_init_sign( (char *) dkim_signing_domain, |
1cfe5c1c | 567 | (char *) dkim_signing_selector, |
f444c2c7 JH |
568 | (char *) dkim_private_key_expanded, |
569 | PDKIM_ALGO_RSA_SHA256); | |
1cfe5c1c JH |
570 | pdkim_set_optional(ctx, |
571 | (char *) dkim_sign_headers_expanded, | |
572 | NULL, | |
573 | pdkim_canon, | |
f444c2c7 | 574 | pdkim_canon, -1, 0, 0); |
1cfe5c1c JH |
575 | |
576 | lseek(dkim_fd, 0, SEEK_SET); | |
577 | ||
578 | while ((sread = read(dkim_fd, &buf, 4096)) > 0) | |
579 | if (pdkim_feed(ctx, buf, sread) != PDKIM_OK) | |
580 | { | |
80a47a2c TK |
581 | rc = NULL; |
582 | goto CLEANUP; | |
1cfe5c1c JH |
583 | } |
584 | ||
585 | /* Handle failed read above. */ | |
586 | if (sread == -1) | |
587 | { | |
588 | debug_printf("DKIM: Error reading -K file.\n"); | |
589 | save_errno = errno; | |
590 | rc = NULL; | |
591 | goto CLEANUP; | |
80a47a2c | 592 | } |
80a47a2c | 593 | |
1cfe5c1c JH |
594 | if ((pdkim_rc = pdkim_feed_finish(ctx, &signature)) != PDKIM_OK) |
595 | { | |
596 | log_write(0, LOG_MAIN|LOG_PANIC, "DKIM: signing failed (RC %d)", pdkim_rc); | |
597 | rc = NULL; | |
598 | goto CLEANUP; | |
a8e1eeba | 599 | } |
80a47a2c | 600 | |
1cfe5c1c JH |
601 | sigbuf = string_append(sigbuf, &sigsize, &sigptr, 2, |
602 | US signature->signature_header, US"\r\n"); | |
80a47a2c | 603 | |
1cfe5c1c JH |
604 | pdkim_free_ctx(ctx); |
605 | ctx = NULL; | |
80a47a2c | 606 | } |
a8e1eeba | 607 | |
1cfe5c1c JH |
608 | if (sigbuf) |
609 | { | |
610 | sigbuf[sigptr] = '\0'; | |
611 | rc = sigbuf; | |
612 | } | |
613 | else | |
614 | rc = US""; | |
615 | ||
616 | CLEANUP: | |
617 | if (ctx) | |
618 | pdkim_free_ctx(ctx); | |
619 | store_pool = old_pool; | |
620 | errno = save_errno; | |
621 | return rc; | |
93f2d376 | 622 | } |
80a47a2c TK |
623 | |
624 | #endif |