Commit | Line | Data |
---|---|---|
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) | |
f7302073 | 31 | return PDKIM_FAIL; /*XXX better error detail? logging? */ |
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) | |
f7302073 | 54 | return PDKIM_FAIL; /*XXX better error detail? logging? */ |
4263f395 | 55 | } |
1cfe5c1c | 56 | return PDKIM_OK; |
80a47a2c | 57 | } |
80a47a2c | 58 | |
f7302073 | 59 | return PDKIM_FAIL; /*XXX better error detail? logging? */ |
80a47a2c TK |
60 | } |
61 | ||
62 | ||
2592e6c0 JH |
63 | void |
64 | dkim_exim_init(void) | |
65 | { | |
66 | pdkim_init(); | |
67 | } | |
68 | ||
69 | ||
ca9cb170 | 70 | |
1cfe5c1c | 71 | void |
e983e85a | 72 | dkim_exim_verify_init(BOOL dot_stuffing) |
1cfe5c1c | 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 | |
e983e85a | 88 | dkim_verify_ctx = pdkim_init_verify(&dkim_exim_query_dns_txt, dot_stuffing); |
3b957582 | 89 | dkim_collect_input = !!dkim_verify_ctx; |
ca9cb170 | 90 | |
584e96c6 JH |
91 | /* Start feed up with any cached data */ |
92 | receive_get_cache(); | |
93 | ||
ca9cb170 | 94 | store_pool = dkim_verify_oldpool; |
80a47a2c TK |
95 | } |
96 | ||
97 | ||
1cfe5c1c JH |
98 | void |
99 | dkim_exim_verify_feed(uschar * data, int len) | |
100 | { | |
f7302073 JH |
101 | int rc; |
102 | ||
ca9cb170 | 103 | store_pool = POOL_PERM; |
1cfe5c1c | 104 | if ( dkim_collect_input |
e983e85a | 105 | && (rc = pdkim_feed(dkim_verify_ctx, CS data, len)) != PDKIM_OK) |
f7302073 JH |
106 | { |
107 | log_write(0, LOG_MAIN, | |
108 | "DKIM: validation error: %.100s", pdkim_errstr(rc)); | |
1cfe5c1c | 109 | dkim_collect_input = FALSE; |
f7302073 | 110 | } |
ca9cb170 | 111 | store_pool = dkim_verify_oldpool; |
80a47a2c TK |
112 | } |
113 | ||
114 | ||
1cfe5c1c JH |
115 | void |
116 | dkim_exim_verify_finish(void) | |
117 | { | |
118 | pdkim_signature *sig = NULL; | |
119 | int dkim_signers_size = 0; | |
120 | int dkim_signers_ptr = 0; | |
121 | dkim_signers = NULL; | |
f7302073 | 122 | int rc; |
1cfe5c1c | 123 | |
ca9cb170 JH |
124 | store_pool = POOL_PERM; |
125 | ||
1cfe5c1c JH |
126 | /* Delete eventual previous signature chain */ |
127 | ||
128 | dkim_signatures = NULL; | |
129 | ||
130 | /* If we have arrived here with dkim_collect_input == FALSE, it | |
131 | means there was a processing error somewhere along the way. | |
132 | Log the incident and disable futher verification. */ | |
133 | ||
134 | if (!dkim_collect_input) | |
135 | { | |
136 | log_write(0, LOG_MAIN, | |
137 | "DKIM: Error while running this message through validation," | |
138 | " disabling signature verification."); | |
139 | dkim_disable_verify = TRUE; | |
ca9cb170 | 140 | goto out; |
1cfe5c1c | 141 | } |
80a47a2c | 142 | |
1cfe5c1c | 143 | dkim_collect_input = FALSE; |
80a47a2c | 144 | |
1cfe5c1c | 145 | /* Finish DKIM operation and fetch link to signatures chain */ |
80a47a2c | 146 | |
f7302073 JH |
147 | if ((rc = pdkim_feed_finish(dkim_verify_ctx, &dkim_signatures)) != PDKIM_OK) |
148 | { | |
149 | log_write(0, LOG_MAIN, | |
150 | "DKIM: validation error: %.100s", pdkim_errstr(rc)); | |
ca9cb170 | 151 | goto out; |
f7302073 | 152 | } |
1cfe5c1c JH |
153 | |
154 | for (sig = dkim_signatures; sig; sig = sig->next) | |
155 | { | |
156 | int size = 0; | |
157 | int ptr = 0; | |
158 | ||
159 | /* Log a line for each signature */ | |
160 | ||
161 | uschar *logmsg = string_append(NULL, &size, &ptr, 5, | |
abe1010c | 162 | string_sprintf("d=%s s=%s c=%s/%s a=%s b=%d ", |
1cfe5c1c JH |
163 | sig->domain, |
164 | sig->selector, | |
07eeb4df | 165 | sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", |
166 | sig->canon_body == PDKIM_CANON_SIMPLE ? "simple" : "relaxed", | |
167 | sig->algo == PDKIM_ALGO_RSA_SHA256 | |
168 | ? "rsa-sha256" | |
169 | : sig->algo == PDKIM_ALGO_RSA_SHA1 ? "rsa-sha1" : "err", | |
170 | (int)sig->sigdata.len > -1 ? sig->sigdata.len * 8 : 0 | |
abe1010c | 171 | ), |
1cfe5c1c JH |
172 | |
173 | sig->identity ? string_sprintf("i=%s ", sig->identity) : US"", | |
174 | sig->created > 0 ? string_sprintf("t=%lu ", sig->created) : US"", | |
175 | sig->expires > 0 ? string_sprintf("x=%lu ", sig->expires) : US"", | |
176 | sig->bodylength > -1 ? string_sprintf("l=%lu ", sig->bodylength) : US"" | |
177 | ); | |
178 | ||
179 | switch (sig->verify_status) | |
180 | { | |
181 | case PDKIM_VERIFY_NONE: | |
182 | logmsg = string_append(logmsg, &size, &ptr, 1, "[not verified]"); | |
80a47a2c | 183 | break; |
1cfe5c1c JH |
184 | |
185 | case PDKIM_VERIFY_INVALID: | |
186 | logmsg = string_append(logmsg, &size, &ptr, 1, "[invalid - "); | |
187 | switch (sig->verify_ext_status) | |
188 | { | |
189 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: | |
190 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
191 | "public key record (currently?) unavailable]"); | |
192 | break; | |
193 | ||
194 | case PDKIM_VERIFY_INVALID_BUFFER_SIZE: | |
195 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
196 | "overlong public key record]"); | |
197 | break; | |
198 | ||
df3def24 JH |
199 | case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: |
200 | case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: | |
1cfe5c1c JH |
201 | logmsg = string_append(logmsg, &size, &ptr, 1, |
202 | "syntax error in public key record]"); | |
203 | break; | |
07eeb4df | 204 | |
205 | case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR: | |
206 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
207 | "signature tag missing or invalid]"); | |
208 | break; | |
209 | ||
210 | case PDKIM_VERIFY_INVALID_DKIM_VERSION: | |
211 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
212 | "unsupported DKIM version]"); | |
213 | break; | |
1cfe5c1c JH |
214 | |
215 | default: | |
216 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
217 | "unspecified problem]"); | |
218 | } | |
80a47a2c | 219 | break; |
1cfe5c1c JH |
220 | |
221 | case PDKIM_VERIFY_FAIL: | |
222 | logmsg = | |
223 | string_append(logmsg, &size, &ptr, 1, "[verification failed - "); | |
224 | switch (sig->verify_ext_status) | |
225 | { | |
226 | case PDKIM_VERIFY_FAIL_BODY: | |
227 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
228 | "body hash mismatch (body probably modified in transit)]"); | |
229 | break; | |
230 | ||
231 | case PDKIM_VERIFY_FAIL_MESSAGE: | |
232 | logmsg = string_append(logmsg, &size, &ptr, 1, | |
233 | "signature did not verify (headers probably modified in transit)]"); | |
234 | break; | |
235 | ||
236 | default: | |
237 | logmsg = string_append(logmsg, &size, &ptr, 1, "unspecified reason]"); | |
238 | } | |
80a47a2c | 239 | break; |
1cfe5c1c JH |
240 | |
241 | case PDKIM_VERIFY_PASS: | |
242 | logmsg = | |
243 | string_append(logmsg, &size, &ptr, 1, "[verification succeeded]"); | |
80a47a2c TK |
244 | break; |
245 | } | |
246 | ||
1cfe5c1c JH |
247 | logmsg[ptr] = '\0'; |
248 | log_write(0, LOG_MAIN, "DKIM: %s", logmsg); | |
80a47a2c | 249 | |
1cfe5c1c JH |
250 | /* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */ |
251 | ||
252 | dkim_signers = string_append(dkim_signers, | |
253 | &dkim_signers_size, | |
254 | &dkim_signers_ptr, 2, sig->domain, ":"); | |
255 | ||
256 | if (sig->identity) | |
9e5d6b55 | 257 | dkim_signers = string_append(dkim_signers, |
1cfe5c1c JH |
258 | &dkim_signers_size, |
259 | &dkim_signers_ptr, 2, sig->identity, ":"); | |
80a47a2c | 260 | |
1cfe5c1c | 261 | /* Process next signature */ |
80a47a2c TK |
262 | } |
263 | ||
1cfe5c1c JH |
264 | /* NULL-terminate and chop the last colon from the domain list */ |
265 | ||
266 | if (dkim_signers) | |
267 | { | |
268 | dkim_signers[dkim_signers_ptr] = '\0'; | |
269 | if (Ustrlen(dkim_signers) > 0) | |
270 | dkim_signers[Ustrlen(dkim_signers) - 1] = '\0'; | |
0d2b278d | 271 | } |
ca9cb170 JH |
272 | |
273 | out: | |
274 | store_pool = dkim_verify_oldpool; | |
80a47a2c TK |
275 | } |
276 | ||
277 | ||
1cfe5c1c JH |
278 | void |
279 | dkim_exim_acl_setup(uschar * id) | |
280 | { | |
281 | pdkim_signature * sig; | |
282 | uschar * cmp_val; | |
283 | ||
1cfe5c1c JH |
284 | dkim_cur_sig = NULL; |
285 | dkim_cur_signer = id; | |
286 | ||
287 | if (dkim_disable_verify || !id || !dkim_verify_ctx) | |
288 | return; | |
289 | ||
290 | /* Find signature to run ACL on */ | |
291 | ||
292 | for (sig = dkim_signatures; sig; sig = sig->next) | |
293 | if ( (cmp_val = Ustrchr(id, '@') != NULL ? US sig->identity : US sig->domain) | |
294 | && strcmpic(cmp_val, id) == 0 | |
295 | ) | |
296 | { | |
297 | dkim_cur_sig = sig; | |
298 | ||
299 | /* The "dkim_domain" and "dkim_selector" expansion variables have | |
300 | related globals, since they are used in the signing code too. | |
301 | Instead of inventing separate names for verification, we set | |
302 | them here. This is easy since a domain and selector is guaranteed | |
303 | to be in a signature. The other dkim_* expansion items are | |
304 | dynamically fetched from dkim_cur_sig at expansion time (see | |
305 | function below). */ | |
306 | ||
307 | dkim_signing_domain = US sig->domain; | |
308 | dkim_signing_selector = US sig->selector; | |
2592e6c0 | 309 | dkim_key_length = sig->sigdata.len * 8; |
1cfe5c1c | 310 | return; |
80a47a2c | 311 | } |
80a47a2c TK |
312 | } |
313 | ||
314 | ||
1cfe5c1c JH |
315 | static uschar * |
316 | dkim_exim_expand_defaults(int what) | |
317 | { | |
318 | switch (what) | |
319 | { | |
320 | case DKIM_ALGO: return US""; | |
321 | case DKIM_BODYLENGTH: return US"9999999999999"; | |
322 | case DKIM_CANON_BODY: return US""; | |
323 | case DKIM_CANON_HEADERS: return US""; | |
324 | case DKIM_COPIEDHEADERS: return US""; | |
325 | case DKIM_CREATED: return US"0"; | |
326 | case DKIM_EXPIRES: return US"9999999999999"; | |
327 | case DKIM_HEADERNAMES: return US""; | |
328 | case DKIM_IDENTITY: return US""; | |
329 | case DKIM_KEY_GRANULARITY: return US"*"; | |
330 | case DKIM_KEY_SRVTYPE: return US"*"; | |
331 | case DKIM_KEY_NOTES: return US""; | |
332 | case DKIM_KEY_TESTING: return US"0"; | |
333 | case DKIM_NOSUBDOMAINS: return US"0"; | |
334 | case DKIM_VERIFY_STATUS: return US"none"; | |
335 | case DKIM_VERIFY_REASON: return US""; | |
336 | default: return US""; | |
337 | } | |
338 | } | |
80a47a2c | 339 | |
80a47a2c | 340 | |
1cfe5c1c JH |
341 | uschar * |
342 | dkim_exim_expand_query(int what) | |
343 | { | |
344 | if (!dkim_verify_ctx || dkim_disable_verify || !dkim_cur_sig) | |
345 | return dkim_exim_expand_defaults(what); | |
346 | ||
347 | switch (what) | |
348 | { | |
349 | case DKIM_ALGO: | |
350 | switch (dkim_cur_sig->algo) | |
351 | { | |
352 | case PDKIM_ALGO_RSA_SHA1: return US"rsa-sha1"; | |
353 | case PDKIM_ALGO_RSA_SHA256: | |
354 | default: return US"rsa-sha256"; | |
da5dfc3a | 355 | } |
1cfe5c1c JH |
356 | |
357 | case DKIM_BODYLENGTH: | |
358 | return dkim_cur_sig->bodylength >= 0 | |
359 | ? string_sprintf(OFF_T_FMT, (LONGLONG_T) dkim_cur_sig->bodylength) | |
360 | : dkim_exim_expand_defaults(what); | |
361 | ||
362 | case DKIM_CANON_BODY: | |
363 | switch (dkim_cur_sig->canon_body) | |
364 | { | |
365 | case PDKIM_CANON_RELAXED: return US"relaxed"; | |
366 | case PDKIM_CANON_SIMPLE: | |
367 | default: return US"simple"; | |
80a47a2c | 368 | } |
1cfe5c1c JH |
369 | |
370 | case DKIM_CANON_HEADERS: | |
371 | switch (dkim_cur_sig->canon_headers) | |
372 | { | |
373 | case PDKIM_CANON_RELAXED: return US"relaxed"; | |
374 | case PDKIM_CANON_SIMPLE: | |
375 | default: return US"simple"; | |
376 | } | |
377 | ||
378 | case DKIM_COPIEDHEADERS: | |
379 | return dkim_cur_sig->copiedheaders | |
380 | ? US dkim_cur_sig->copiedheaders : dkim_exim_expand_defaults(what); | |
381 | ||
382 | case DKIM_CREATED: | |
383 | return dkim_cur_sig->created > 0 | |
384 | ? string_sprintf("%llu", dkim_cur_sig->created) | |
385 | : dkim_exim_expand_defaults(what); | |
386 | ||
387 | case DKIM_EXPIRES: | |
388 | return dkim_cur_sig->expires > 0 | |
389 | ? string_sprintf("%llu", dkim_cur_sig->expires) | |
390 | : dkim_exim_expand_defaults(what); | |
391 | ||
392 | case DKIM_HEADERNAMES: | |
393 | return dkim_cur_sig->headernames | |
2592e6c0 | 394 | ? dkim_cur_sig->headernames : dkim_exim_expand_defaults(what); |
1cfe5c1c JH |
395 | |
396 | case DKIM_IDENTITY: | |
397 | return dkim_cur_sig->identity | |
398 | ? US dkim_cur_sig->identity : dkim_exim_expand_defaults(what); | |
399 | ||
400 | case DKIM_KEY_GRANULARITY: | |
401 | return dkim_cur_sig->pubkey | |
402 | ? dkim_cur_sig->pubkey->granularity | |
403 | ? US dkim_cur_sig->pubkey->granularity | |
404 | : dkim_exim_expand_defaults(what) | |
405 | : dkim_exim_expand_defaults(what); | |
406 | ||
407 | case DKIM_KEY_SRVTYPE: | |
408 | return dkim_cur_sig->pubkey | |
409 | ? dkim_cur_sig->pubkey->srvtype | |
410 | ? US dkim_cur_sig->pubkey->srvtype | |
411 | : dkim_exim_expand_defaults(what) | |
412 | : dkim_exim_expand_defaults(what); | |
413 | ||
414 | case DKIM_KEY_NOTES: | |
415 | return dkim_cur_sig->pubkey | |
416 | ? dkim_cur_sig->pubkey->notes | |
417 | ? US dkim_cur_sig->pubkey->notes | |
418 | : dkim_exim_expand_defaults(what) | |
419 | : dkim_exim_expand_defaults(what); | |
420 | ||
421 | case DKIM_KEY_TESTING: | |
422 | return dkim_cur_sig->pubkey | |
423 | ? dkim_cur_sig->pubkey->testing | |
424 | ? US"1" | |
425 | : dkim_exim_expand_defaults(what) | |
426 | : dkim_exim_expand_defaults(what); | |
427 | ||
428 | case DKIM_NOSUBDOMAINS: | |
429 | return dkim_cur_sig->pubkey | |
430 | ? dkim_cur_sig->pubkey->no_subdomaining | |
431 | ? US"1" | |
432 | : dkim_exim_expand_defaults(what) | |
433 | : dkim_exim_expand_defaults(what); | |
434 | ||
435 | case DKIM_VERIFY_STATUS: | |
436 | switch (dkim_cur_sig->verify_status) | |
437 | { | |
438 | case PDKIM_VERIFY_INVALID: return US"invalid"; | |
439 | case PDKIM_VERIFY_FAIL: return US"fail"; | |
440 | case PDKIM_VERIFY_PASS: return US"pass"; | |
441 | case PDKIM_VERIFY_NONE: | |
442 | default: return US"none"; | |
80a47a2c | 443 | } |
80a47a2c | 444 | |
1cfe5c1c JH |
445 | case DKIM_VERIFY_REASON: |
446 | switch (dkim_cur_sig->verify_ext_status) | |
447 | { | |
448 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: | |
449 | return US"pubkey_unavailable"; | |
df3def24 JH |
450 | case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD:return US"pubkey_dns_syntax"; |
451 | case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return US"pubkey_der_syntax"; | |
1cfe5c1c JH |
452 | case PDKIM_VERIFY_FAIL_BODY: return US"bodyhash_mismatch"; |
453 | case PDKIM_VERIFY_FAIL_MESSAGE: return US"signature_incorrect"; | |
454 | } | |
80a47a2c | 455 | |
1cfe5c1c JH |
456 | default: |
457 | return US""; | |
80a47a2c TK |
458 | } |
459 | } | |
460 | ||
461 | ||
55414b25 | 462 | uschar * |
e983e85a | 463 | dkim_exim_sign(int dkim_fd, struct ob_dkim * dkim) |
55414b25 | 464 | { |
e983e85a | 465 | const uschar * dkim_domain; |
1cfe5c1c JH |
466 | int sep = 0; |
467 | uschar *seen_items = NULL; | |
468 | int seen_items_size = 0; | |
469 | int seen_items_offset = 0; | |
470 | uschar itembuf[256]; | |
471 | uschar *dkim_canon_expanded; | |
472 | uschar *dkim_sign_headers_expanded; | |
473 | uschar *dkim_private_key_expanded; | |
474 | pdkim_ctx *ctx = NULL; | |
475 | uschar *rc = NULL; | |
476 | uschar *sigbuf = NULL; | |
477 | int sigsize = 0; | |
478 | int sigptr = 0; | |
479 | pdkim_signature *signature; | |
480 | int pdkim_canon; | |
481 | int pdkim_rc; | |
482 | int sread; | |
483 | char buf[4096]; | |
484 | int save_errno = 0; | |
485 | int old_pool = store_pool; | |
486 | ||
487 | store_pool = POOL_MAIN; | |
488 | ||
e983e85a | 489 | if (!(dkim_domain = expand_cstring(dkim->dkim_domain))) |
1cfe5c1c JH |
490 | { |
491 | /* expansion error, do not send message. */ | |
492 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
493 | "dkim_domain: %s", expand_string_message); | |
f7302073 | 494 | goto bad; |
1cfe5c1c JH |
495 | } |
496 | ||
497 | /* Set $dkim_domain expansion variable to each unique domain in list. */ | |
498 | ||
499 | while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, | |
500 | itembuf, sizeof(itembuf)))) | |
501 | { | |
502 | if (!dkim_signing_domain || dkim_signing_domain[0] == '\0') | |
503 | continue; | |
504 | ||
505 | /* Only sign once for each domain, no matter how often it | |
506 | appears in the expanded list. */ | |
507 | ||
508 | if (seen_items) | |
509 | { | |
510 | const uschar *seen_items_list = seen_items; | |
511 | if (match_isinlist(dkim_signing_domain, | |
512 | &seen_items_list, 0, NULL, NULL, MCL_STRING, TRUE, | |
513 | NULL) == OK) | |
514 | continue; | |
515 | ||
516 | seen_items = | |
517 | string_append(seen_items, &seen_items_size, &seen_items_offset, 1, ":"); | |
518 | } | |
519 | ||
520 | seen_items = | |
521 | string_append(seen_items, &seen_items_size, &seen_items_offset, 1, | |
522 | dkim_signing_domain); | |
523 | seen_items[seen_items_offset] = '\0'; | |
524 | ||
525 | /* Set up $dkim_selector expansion variable. */ | |
526 | ||
e983e85a | 527 | if (!(dkim_signing_selector = expand_string(dkim->dkim_selector))) |
1cfe5c1c JH |
528 | { |
529 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
530 | "dkim_selector: %s", expand_string_message); | |
f7302073 | 531 | goto bad; |
1cfe5c1c JH |
532 | } |
533 | ||
534 | /* Get canonicalization to use */ | |
535 | ||
e983e85a JH |
536 | dkim_canon_expanded = dkim->dkim_canon |
537 | ? expand_string(dkim->dkim_canon) : US"relaxed"; | |
1cfe5c1c JH |
538 | if (!dkim_canon_expanded) |
539 | { | |
80a47a2c | 540 | /* expansion error, do not send message. */ |
1cfe5c1c JH |
541 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " |
542 | "dkim_canon: %s", expand_string_message); | |
f7302073 | 543 | goto bad; |
1cfe5c1c | 544 | } |
80a47a2c | 545 | |
1cfe5c1c JH |
546 | if (Ustrcmp(dkim_canon_expanded, "relaxed") == 0) |
547 | pdkim_canon = PDKIM_CANON_RELAXED; | |
548 | else if (Ustrcmp(dkim_canon_expanded, "simple") == 0) | |
549 | pdkim_canon = PDKIM_CANON_SIMPLE; | |
550 | else | |
551 | { | |
552 | log_write(0, LOG_MAIN, | |
553 | "DKIM: unknown canonicalization method '%s', defaulting to 'relaxed'.\n", | |
554 | dkim_canon_expanded); | |
555 | pdkim_canon = PDKIM_CANON_RELAXED; | |
a8e1eeba | 556 | } |
1cfe5c1c JH |
557 | |
558 | dkim_sign_headers_expanded = NULL; | |
e983e85a JH |
559 | if (dkim->dkim_sign_headers) |
560 | if (!(dkim_sign_headers_expanded = expand_string(dkim->dkim_sign_headers))) | |
1cfe5c1c JH |
561 | { |
562 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
563 | "dkim_sign_headers: %s", expand_string_message); | |
f7302073 | 564 | goto bad; |
1cfe5c1c JH |
565 | } |
566 | /* else pass NULL, which means default header list */ | |
567 | ||
568 | /* Get private key to use. */ | |
569 | ||
e983e85a | 570 | if (!(dkim_private_key_expanded = expand_string(dkim->dkim_private_key))) |
1cfe5c1c JH |
571 | { |
572 | log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand " | |
573 | "dkim_private_key: %s", expand_string_message); | |
f7302073 | 574 | goto bad; |
a8e1eeba | 575 | } |
80a47a2c | 576 | |
1cfe5c1c JH |
577 | if ( Ustrlen(dkim_private_key_expanded) == 0 |
578 | || Ustrcmp(dkim_private_key_expanded, "0") == 0 | |
579 | || Ustrcmp(dkim_private_key_expanded, "false") == 0 | |
580 | ) | |
581 | continue; /* don't sign, but no error */ | |
582 | ||
583 | if (dkim_private_key_expanded[0] == '/') | |
584 | { | |
585 | int privkey_fd = 0; | |
586 | ||
587 | /* Looks like a filename, load the private key. */ | |
588 | ||
589 | memset(big_buffer, 0, big_buffer_size); | |
e983e85a JH |
590 | |
591 | if ((privkey_fd = open(CS dkim_private_key_expanded, O_RDONLY)) < 0) | |
1cfe5c1c JH |
592 | { |
593 | log_write(0, LOG_MAIN | LOG_PANIC, "unable to open " | |
594 | "private key file for reading: %s", | |
595 | dkim_private_key_expanded); | |
f7302073 | 596 | goto bad; |
db4d0902 | 597 | } |
80a47a2c | 598 | |
1cfe5c1c JH |
599 | if (read(privkey_fd, big_buffer, big_buffer_size - 2) < 0) |
600 | { | |
601 | log_write(0, LOG_MAIN|LOG_PANIC, "unable to read private key file: %s", | |
602 | dkim_private_key_expanded); | |
f7302073 | 603 | goto bad; |
1ac6b2e7 | 604 | } |
80a47a2c | 605 | |
1cfe5c1c JH |
606 | (void) close(privkey_fd); |
607 | dkim_private_key_expanded = big_buffer; | |
a8e1eeba | 608 | } |
1cfe5c1c | 609 | |
f7302073 JH |
610 | ctx = pdkim_init_sign( CS dkim_signing_domain, |
611 | CS dkim_signing_selector, | |
612 | CS dkim_private_key_expanded, | |
e983e85a JH |
613 | PDKIM_ALGO_RSA_SHA256, |
614 | dkim->dot_stuffed); | |
1cfe5c1c | 615 | pdkim_set_optional(ctx, |
e983e85a | 616 | CS dkim_sign_headers_expanded, |
1cfe5c1c JH |
617 | NULL, |
618 | pdkim_canon, | |
f444c2c7 | 619 | pdkim_canon, -1, 0, 0); |
1cfe5c1c JH |
620 | |
621 | lseek(dkim_fd, 0, SEEK_SET); | |
622 | ||
e983e85a | 623 | while ((sread = read(dkim_fd, &buf, sizeof(buf))) > 0) |
f7302073 JH |
624 | if ((pdkim_rc = pdkim_feed(ctx, buf, sread)) != PDKIM_OK) |
625 | goto pk_bad; | |
1cfe5c1c JH |
626 | |
627 | /* Handle failed read above. */ | |
628 | if (sread == -1) | |
629 | { | |
630 | debug_printf("DKIM: Error reading -K file.\n"); | |
631 | save_errno = errno; | |
f7302073 | 632 | goto bad; |
80a47a2c | 633 | } |
80a47a2c | 634 | |
1cfe5c1c | 635 | if ((pdkim_rc = pdkim_feed_finish(ctx, &signature)) != PDKIM_OK) |
f7302073 | 636 | goto pk_bad; |
80a47a2c | 637 | |
1cfe5c1c JH |
638 | sigbuf = string_append(sigbuf, &sigsize, &sigptr, 2, |
639 | US signature->signature_header, US"\r\n"); | |
80a47a2c | 640 | |
1cfe5c1c JH |
641 | pdkim_free_ctx(ctx); |
642 | ctx = NULL; | |
80a47a2c | 643 | } |
a8e1eeba | 644 | |
1cfe5c1c JH |
645 | if (sigbuf) |
646 | { | |
647 | sigbuf[sigptr] = '\0'; | |
648 | rc = sigbuf; | |
649 | } | |
650 | else | |
651 | rc = US""; | |
652 | ||
653 | CLEANUP: | |
f7302073 JH |
654 | if (ctx) |
655 | pdkim_free_ctx(ctx); | |
656 | store_pool = old_pool; | |
657 | errno = save_errno; | |
658 | return rc; | |
659 | ||
660 | pk_bad: | |
661 | log_write(0, LOG_MAIN|LOG_PANIC, | |
662 | "DKIM: signing failed: %.100s", pdkim_errstr(pdkim_rc)); | |
663 | bad: | |
664 | rc = NULL; | |
665 | goto CLEANUP; | |
93f2d376 | 666 | } |
80a47a2c TK |
667 | |
668 | #endif |