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80a47a2c TK |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
0a49a7a4 | 5 | /* Copyright (c) University of Cambridge, 1995 - 2007 */ |
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 | ||
17 | pdkim_ctx *dkim_verify_ctx = NULL; | |
18 | pdkim_signature *dkim_signatures = NULL; | |
19 | pdkim_signature *dkim_cur_sig = NULL; | |
20 | ||
21 | int dkim_exim_query_dns_txt(char *name, char *answer) { | |
22 | dns_answer dnsa; | |
23 | dns_scan dnss; | |
24 | dns_record *rr; | |
25 | ||
26 | if (dns_lookup(&dnsa, (uschar *)name, T_TXT, NULL) != DNS_SUCCEED) return PDKIM_FAIL; | |
27 | ||
28 | /* Search for TXT record */ | |
29 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
30 | rr != NULL; | |
31 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
32 | if (rr->type == T_TXT) break; | |
33 | ||
34 | /* Copy record content to the answer buffer */ | |
35 | if (rr != NULL) { | |
36 | int rr_offset = 0; | |
37 | int answer_offset = 0; | |
38 | while (rr_offset < rr->size) { | |
39 | uschar len = (rr->data)[rr_offset++]; | |
40 | snprintf(answer+(answer_offset), | |
41 | PDKIM_DNS_TXT_MAX_RECLEN-(answer_offset), | |
42 | "%.*s", (int)len, (char *)((rr->data)+rr_offset)); | |
43 | rr_offset+=len; | |
44 | answer_offset+=len; | |
4263f395 PP |
45 | if (answer_offset >= PDKIM_DNS_TXT_MAX_RECLEN) { |
46 | return PDKIM_FAIL; | |
47 | } | |
80a47a2c TK |
48 | } |
49 | } | |
50 | else return PDKIM_FAIL; | |
51 | ||
52 | return PDKIM_OK; | |
53 | } | |
54 | ||
55 | ||
56 | void dkim_exim_verify_init(void) { | |
57 | ||
58 | /* Free previous context if there is one */ | |
59 | if (dkim_verify_ctx) pdkim_free_ctx(dkim_verify_ctx); | |
60 | ||
61 | /* Create new context */ | |
62 | dkim_verify_ctx = pdkim_init_verify(PDKIM_INPUT_SMTP, | |
63 | &dkim_exim_query_dns_txt | |
64 | ); | |
65 | ||
66 | if (dkim_verify_ctx != NULL) { | |
67 | dkim_collect_input = TRUE; | |
68 | pdkim_set_debug_stream(dkim_verify_ctx,debug_file); | |
69 | } | |
70 | else dkim_collect_input = FALSE; | |
71 | ||
72 | } | |
73 | ||
74 | ||
75 | void dkim_exim_verify_feed(uschar *data, int len) { | |
76 | if (dkim_collect_input && | |
77 | pdkim_feed(dkim_verify_ctx, | |
78 | (char *)data, | |
79 | len) != PDKIM_OK) dkim_collect_input = FALSE; | |
80 | } | |
81 | ||
82 | ||
83 | void dkim_exim_verify_finish(void) { | |
84 | pdkim_signature *sig = NULL; | |
9e5d6b55 TK |
85 | int dkim_signers_size = 0; |
86 | int dkim_signers_ptr = 0; | |
87 | dkim_signers = NULL; | |
80a47a2c TK |
88 | |
89 | /* Delete eventual previous signature chain */ | |
90 | dkim_signatures = NULL; | |
91 | ||
92 | /* If we have arrived here with dkim_collect_input == FALSE, it | |
93 | means there was a processing error somewhere along the way. | |
94 | Log the incident and disable futher verification. */ | |
95 | if (!dkim_collect_input) { | |
d4f333f7 | 96 | log_write(0, LOG_MAIN, "DKIM: Error while running this message through validation, disabling signature verification."); |
80a47a2c TK |
97 | dkim_disable_verify = TRUE; |
98 | return; | |
99 | } | |
100 | dkim_collect_input = FALSE; | |
101 | ||
102 | /* Finish DKIM operation and fetch link to signatures chain */ | |
103 | if (pdkim_feed_finish(dkim_verify_ctx,&dkim_signatures) != PDKIM_OK) return; | |
104 | ||
105 | sig = dkim_signatures; | |
106 | while (sig != NULL) { | |
107 | int size = 0; | |
108 | int ptr = 0; | |
109 | /* Log a line for each signature */ | |
110 | uschar *logmsg = string_append(NULL, &size, &ptr, 5, | |
111 | ||
337e3505 | 112 | string_sprintf( "d=%s s=%s c=%s/%s a=%s ", |
80a47a2c TK |
113 | sig->domain, |
114 | sig->selector, | |
115 | (sig->canon_headers == PDKIM_CANON_SIMPLE)?"simple":"relaxed", | |
116 | (sig->canon_body == PDKIM_CANON_SIMPLE)?"simple":"relaxed", | |
117 | (sig->algo == PDKIM_ALGO_RSA_SHA256)?"rsa-sha256":"rsa-sha1" | |
118 | ), | |
119 | ((sig->identity != NULL)? | |
120 | string_sprintf("i=%s ", sig->identity) | |
121 | : | |
122 | US"" | |
123 | ), | |
124 | ((sig->created > 0)? | |
125 | string_sprintf("t=%lu ", sig->created) | |
126 | : | |
127 | US"" | |
128 | ), | |
129 | ((sig->expires > 0)? | |
130 | string_sprintf("x=%lu ", sig->expires) | |
131 | : | |
132 | US"" | |
133 | ), | |
134 | ((sig->bodylength > -1)? | |
135 | string_sprintf("l=%lu ", sig->bodylength) | |
136 | : | |
137 | US"" | |
138 | ) | |
139 | ); | |
140 | ||
141 | switch(sig->verify_status) { | |
142 | case PDKIM_VERIFY_NONE: | |
143 | logmsg = string_append(logmsg, &size, &ptr, 1, "[not verified]"); | |
144 | break; | |
145 | case PDKIM_VERIFY_INVALID: | |
146 | logmsg = string_append(logmsg, &size, &ptr, 1, "[invalid - "); | |
147 | switch (sig->verify_ext_status) { | |
148 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: | |
149 | logmsg = string_append(logmsg, &size, &ptr, 1, "public key record (currently?) unavailable]"); | |
150 | break; | |
151 | case PDKIM_VERIFY_INVALID_BUFFER_SIZE: | |
152 | logmsg = string_append(logmsg, &size, &ptr, 1, "overlong public key record]"); | |
153 | break; | |
154 | case PDKIM_VERIFY_INVALID_PUBKEY_PARSING: | |
155 | logmsg = string_append(logmsg, &size, &ptr, 1, "syntax error in public key record]"); | |
156 | break; | |
157 | default: | |
158 | logmsg = string_append(logmsg, &size, &ptr, 1, "unspecified problem]"); | |
159 | } | |
160 | break; | |
161 | case PDKIM_VERIFY_FAIL: | |
162 | logmsg = string_append(logmsg, &size, &ptr, 1, "[verification failed - "); | |
163 | switch (sig->verify_ext_status) { | |
164 | case PDKIM_VERIFY_FAIL_BODY: | |
165 | logmsg = string_append(logmsg, &size, &ptr, 1, "body hash mismatch (body probably modified in transit)]"); | |
166 | break; | |
167 | case PDKIM_VERIFY_FAIL_MESSAGE: | |
168 | logmsg = string_append(logmsg, &size, &ptr, 1, "signature did not verify (headers probably modified in transit)]"); | |
169 | break; | |
170 | default: | |
171 | logmsg = string_append(logmsg, &size, &ptr, 1, "unspecified reason]"); | |
172 | } | |
173 | break; | |
174 | case PDKIM_VERIFY_PASS: | |
175 | logmsg = string_append(logmsg, &size, &ptr, 1, "[verification succeeded]"); | |
176 | break; | |
177 | } | |
178 | ||
179 | logmsg[ptr] = '\0'; | |
337e3505 | 180 | log_write(0, LOG_MAIN, "DKIM: %s", logmsg); |
80a47a2c | 181 | |
9e5d6b55 TK |
182 | /* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */ |
183 | dkim_signers = string_append(dkim_signers, | |
184 | &dkim_signers_size, | |
185 | &dkim_signers_ptr, | |
186 | 2, | |
187 | sig->domain, | |
188 | ":" | |
189 | ); | |
190 | ||
191 | if (sig->identity != NULL) { | |
192 | dkim_signers = string_append(dkim_signers, | |
193 | &dkim_signers_size, | |
194 | &dkim_signers_ptr, | |
195 | 2, | |
196 | sig->identity, | |
197 | ":" | |
198 | ); | |
199 | } | |
80a47a2c TK |
200 | |
201 | /* Process next signature */ | |
202 | sig = sig->next; | |
203 | } | |
204 | ||
0d2b278d TK |
205 | /* NULL-terminate and chop the last colon from the domain list */ |
206 | if (dkim_signers != NULL) { | |
207 | dkim_signers[dkim_signers_ptr] = '\0'; | |
208 | if (Ustrlen(dkim_signers) > 0) | |
209 | dkim_signers[Ustrlen(dkim_signers)-1] = '\0'; | |
210 | } | |
80a47a2c TK |
211 | } |
212 | ||
213 | ||
214 | void dkim_exim_acl_setup(uschar *id) { | |
215 | pdkim_signature *sig = dkim_signatures; | |
216 | dkim_cur_sig = NULL; | |
9e5d6b55 | 217 | dkim_cur_signer = id; |
80a47a2c | 218 | if (dkim_disable_verify || |
9e5d6b55 | 219 | !id || !dkim_verify_ctx) return; |
80a47a2c TK |
220 | /* Find signature to run ACL on */ |
221 | while (sig != NULL) { | |
222 | uschar *cmp_val = NULL; | |
223 | if (Ustrchr(id,'@') != NULL) cmp_val = (uschar *)sig->identity; | |
224 | else cmp_val = (uschar *)sig->domain; | |
225 | if (cmp_val && (strcmpic(cmp_val,id) == 0)) { | |
226 | dkim_cur_sig = sig; | |
227 | /* The "dkim_domain" and "dkim_selector" expansion variables have | |
228 | related globals, since they are used in the signing code too. | |
229 | Instead of inventing separate names for verification, we set | |
230 | them here. This is easy since a domain and selector is guaranteed | |
231 | to be in a signature. The other dkim_* expansion items are | |
232 | dynamically fetched from dkim_cur_sig at expansion time (see | |
233 | function below). */ | |
234 | dkim_signing_domain = (uschar *)sig->domain; | |
235 | dkim_signing_selector = (uschar *)sig->selector; | |
236 | return; | |
237 | } | |
238 | sig = sig->next; | |
239 | } | |
240 | } | |
241 | ||
242 | ||
243 | uschar *dkim_exim_expand_query(int what) { | |
244 | ||
245 | if (!dkim_verify_ctx || | |
246 | dkim_disable_verify || | |
247 | !dkim_cur_sig) return dkim_exim_expand_defaults(what); | |
248 | ||
249 | switch(what) { | |
250 | case DKIM_ALGO: | |
da5dfc3a TK |
251 | switch(dkim_cur_sig->algo) { |
252 | case PDKIM_ALGO_RSA_SHA1: | |
253 | return US"rsa-sha1"; | |
254 | case PDKIM_ALGO_RSA_SHA256: | |
255 | default: | |
256 | return US"rsa-sha256"; | |
257 | } | |
80a47a2c TK |
258 | case DKIM_BODYLENGTH: |
259 | return (dkim_cur_sig->bodylength >= 0)? | |
260 | (uschar *)string_sprintf(OFF_T_FMT,(LONGLONG_T)dkim_cur_sig->bodylength) | |
261 | :dkim_exim_expand_defaults(what); | |
262 | case DKIM_CANON_BODY: | |
da5dfc3a TK |
263 | switch(dkim_cur_sig->canon_body) { |
264 | case PDKIM_CANON_RELAXED: | |
265 | return US"relaxed"; | |
266 | case PDKIM_CANON_SIMPLE: | |
267 | default: | |
268 | return US"simple"; | |
269 | } | |
80a47a2c | 270 | case DKIM_CANON_HEADERS: |
da5dfc3a TK |
271 | switch(dkim_cur_sig->canon_headers) { |
272 | case PDKIM_CANON_RELAXED: | |
273 | return US"relaxed"; | |
274 | case PDKIM_CANON_SIMPLE: | |
275 | default: | |
276 | return US"simple"; | |
277 | } | |
80a47a2c TK |
278 | case DKIM_COPIEDHEADERS: |
279 | return dkim_cur_sig->copiedheaders? | |
280 | (uschar *)(dkim_cur_sig->copiedheaders) | |
281 | :dkim_exim_expand_defaults(what); | |
282 | case DKIM_CREATED: | |
283 | return (dkim_cur_sig->created > 0)? | |
284 | (uschar *)string_sprintf("%llu",dkim_cur_sig->created) | |
285 | :dkim_exim_expand_defaults(what); | |
286 | case DKIM_EXPIRES: | |
287 | return (dkim_cur_sig->expires > 0)? | |
288 | (uschar *)string_sprintf("%llu",dkim_cur_sig->expires) | |
289 | :dkim_exim_expand_defaults(what); | |
290 | case DKIM_HEADERNAMES: | |
291 | return dkim_cur_sig->headernames? | |
292 | (uschar *)(dkim_cur_sig->headernames) | |
293 | :dkim_exim_expand_defaults(what); | |
294 | case DKIM_IDENTITY: | |
295 | return dkim_cur_sig->identity? | |
296 | (uschar *)(dkim_cur_sig->identity) | |
297 | :dkim_exim_expand_defaults(what); | |
298 | case DKIM_KEY_GRANULARITY: | |
299 | return dkim_cur_sig->pubkey? | |
300 | (dkim_cur_sig->pubkey->granularity? | |
301 | (uschar *)(dkim_cur_sig->pubkey->granularity) | |
302 | :dkim_exim_expand_defaults(what) | |
303 | ) | |
304 | :dkim_exim_expand_defaults(what); | |
305 | case DKIM_KEY_SRVTYPE: | |
306 | return dkim_cur_sig->pubkey? | |
307 | (dkim_cur_sig->pubkey->srvtype? | |
308 | (uschar *)(dkim_cur_sig->pubkey->srvtype) | |
309 | :dkim_exim_expand_defaults(what) | |
310 | ) | |
311 | :dkim_exim_expand_defaults(what); | |
312 | case DKIM_KEY_NOTES: | |
313 | return dkim_cur_sig->pubkey? | |
314 | (dkim_cur_sig->pubkey->notes? | |
315 | (uschar *)(dkim_cur_sig->pubkey->notes) | |
316 | :dkim_exim_expand_defaults(what) | |
317 | ) | |
318 | :dkim_exim_expand_defaults(what); | |
319 | case DKIM_KEY_TESTING: | |
320 | return dkim_cur_sig->pubkey? | |
321 | (dkim_cur_sig->pubkey->testing? | |
322 | US"1" | |
323 | :dkim_exim_expand_defaults(what) | |
324 | ) | |
325 | :dkim_exim_expand_defaults(what); | |
326 | case DKIM_NOSUBDOMAINS: | |
327 | return dkim_cur_sig->pubkey? | |
328 | (dkim_cur_sig->pubkey->no_subdomaining? | |
329 | US"1" | |
330 | :dkim_exim_expand_defaults(what) | |
331 | ) | |
332 | :dkim_exim_expand_defaults(what); | |
333 | case DKIM_VERIFY_STATUS: | |
334 | switch(dkim_cur_sig->verify_status) { | |
335 | case PDKIM_VERIFY_INVALID: | |
336 | return US"invalid"; | |
337 | case PDKIM_VERIFY_FAIL: | |
338 | return US"fail"; | |
339 | case PDKIM_VERIFY_PASS: | |
340 | return US"pass"; | |
341 | case PDKIM_VERIFY_NONE: | |
342 | default: | |
343 | return US"none"; | |
344 | } | |
345 | case DKIM_VERIFY_REASON: | |
346 | switch (dkim_cur_sig->verify_ext_status) { | |
347 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: | |
348 | return US"pubkey_unavailable"; | |
349 | case PDKIM_VERIFY_INVALID_PUBKEY_PARSING: | |
350 | return US"pubkey_syntax"; | |
351 | case PDKIM_VERIFY_FAIL_BODY: | |
352 | return US"bodyhash_mismatch"; | |
353 | case PDKIM_VERIFY_FAIL_MESSAGE: | |
354 | return US"signature_incorrect"; | |
355 | } | |
356 | default: | |
357 | return US""; | |
358 | } | |
359 | } | |
360 | ||
361 | ||
362 | uschar *dkim_exim_expand_defaults(int what) { | |
363 | switch(what) { | |
364 | case DKIM_ALGO: return US""; | |
365 | case DKIM_BODYLENGTH: return US"9999999999999"; | |
366 | case DKIM_CANON_BODY: return US""; | |
367 | case DKIM_CANON_HEADERS: return US""; | |
368 | case DKIM_COPIEDHEADERS: return US""; | |
369 | case DKIM_CREATED: return US"0"; | |
370 | case DKIM_EXPIRES: return US"9999999999999"; | |
371 | case DKIM_HEADERNAMES: return US""; | |
372 | case DKIM_IDENTITY: return US""; | |
373 | case DKIM_KEY_GRANULARITY: return US"*"; | |
374 | case DKIM_KEY_SRVTYPE: return US"*"; | |
375 | case DKIM_KEY_NOTES: return US""; | |
376 | case DKIM_KEY_TESTING: return US"0"; | |
377 | case DKIM_NOSUBDOMAINS: return US"0"; | |
378 | case DKIM_VERIFY_STATUS: return US"none"; | |
379 | case DKIM_VERIFY_REASON: return US""; | |
380 | default: return US""; | |
381 | } | |
382 | } | |
383 | ||
384 | ||
385 | uschar *dkim_exim_sign(int dkim_fd, | |
386 | uschar *dkim_private_key, | |
387 | uschar *dkim_domain, | |
388 | uschar *dkim_selector, | |
389 | uschar *dkim_canon, | |
390 | uschar *dkim_sign_headers) { | |
a8e1eeba MH |
391 | int sep = 0; |
392 | uschar *seen_items = NULL; | |
393 | int seen_items_size = 0; | |
394 | int seen_items_offset = 0; | |
395 | uschar itembuf[256]; | |
396 | uschar *dkim_canon_expanded; | |
397 | uschar *dkim_sign_headers_expanded; | |
398 | uschar *dkim_private_key_expanded; | |
80a47a2c TK |
399 | pdkim_ctx *ctx = NULL; |
400 | uschar *rc = NULL; | |
bc4bc4c5 PP |
401 | uschar *sigbuf = NULL; |
402 | int sigsize = 0; | |
403 | int sigptr = 0; | |
80a47a2c TK |
404 | pdkim_signature *signature; |
405 | int pdkim_canon; | |
dcdf4e3e | 406 | int pdkim_rc; |
80a47a2c TK |
407 | int sread; |
408 | char buf[4096]; | |
409 | int save_errno = 0; | |
410 | int old_pool = store_pool; | |
411 | ||
bc4bc4c5 PP |
412 | store_pool = POOL_MAIN; |
413 | ||
80a47a2c TK |
414 | dkim_domain = expand_string(dkim_domain); |
415 | if (dkim_domain == NULL) { | |
416 | /* expansion error, do not send message. */ | |
417 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " | |
418 | "dkim_domain: %s", expand_string_message); | |
419 | rc = NULL; | |
420 | goto CLEANUP; | |
421 | } | |
80a47a2c | 422 | |
a8e1eeba MH |
423 | /* Set $dkim_domain expansion variable to each unique domain in list. */ |
424 | while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, | |
425 | itembuf, | |
426 | sizeof(itembuf))) != NULL) { | |
427 | if (!dkim_signing_domain || (dkim_signing_domain[0] == '\0')) continue; | |
428 | /* Only sign once for each domain, no matter how often it | |
429 | appears in the expanded list. */ | |
430 | if (seen_items != NULL) { | |
431 | uschar *seen_items_list = seen_items; | |
432 | if (match_isinlist(dkim_signing_domain, | |
433 | &seen_items_list,0,NULL,NULL,MCL_STRING,TRUE,NULL) == OK) | |
434 | continue; | |
435 | seen_items = string_append(seen_items,&seen_items_size,&seen_items_offset,1,":"); | |
436 | } | |
437 | seen_items = string_append(seen_items,&seen_items_size,&seen_items_offset,1,dkim_signing_domain); | |
438 | seen_items[seen_items_offset] = '\0'; | |
80a47a2c | 439 | |
a8e1eeba MH |
440 | /* Set up $dkim_selector expansion variable. */ |
441 | dkim_signing_selector = expand_string(dkim_selector); | |
442 | if (dkim_signing_selector == NULL) { | |
443 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " | |
444 | "dkim_selector: %s", expand_string_message); | |
445 | rc = NULL; | |
446 | goto CLEANUP; | |
447 | } | |
80a47a2c | 448 | |
a8e1eeba MH |
449 | /* Get canonicalization to use */ |
450 | dkim_canon_expanded = expand_string(dkim_canon?dkim_canon:US"relaxed"); | |
451 | if (dkim_canon_expanded == NULL) { | |
452 | /* expansion error, do not send message. */ | |
80a47a2c | 453 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " |
a8e1eeba | 454 | "dkim_canon: %s", expand_string_message); |
80a47a2c TK |
455 | rc = NULL; |
456 | goto CLEANUP; | |
457 | } | |
a8e1eeba MH |
458 | if (Ustrcmp(dkim_canon_expanded, "relaxed") == 0) |
459 | pdkim_canon = PDKIM_CANON_RELAXED; | |
460 | else if (Ustrcmp(dkim_canon_expanded, "simple") == 0) | |
461 | pdkim_canon = PDKIM_CANON_SIMPLE; | |
462 | else { | |
463 | log_write(0, LOG_MAIN, "DKIM: unknown canonicalization method '%s', defaulting to 'relaxed'.\n",dkim_canon_expanded); | |
464 | pdkim_canon = PDKIM_CANON_RELAXED; | |
465 | } | |
80a47a2c | 466 | |
db4d0902 MH |
467 | if (dkim_sign_headers) { |
468 | dkim_sign_headers_expanded = expand_string(dkim_sign_headers); | |
469 | if (dkim_sign_headers_expanded == NULL) { | |
470 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " | |
471 | "dkim_sign_headers: %s", expand_string_message); | |
472 | rc = NULL; | |
473 | goto CLEANUP; | |
474 | } | |
a8e1eeba | 475 | } |
c1b141a8 NM |
476 | else { |
477 | /* pass NULL, which means default header list */ | |
478 | dkim_sign_headers_expanded = NULL; | |
479 | } | |
80a47a2c | 480 | |
a8e1eeba MH |
481 | /* Get private key to use. */ |
482 | dkim_private_key_expanded = expand_string(dkim_private_key); | |
483 | if (dkim_private_key_expanded == NULL) { | |
484 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " | |
485 | "dkim_private_key: %s", expand_string_message); | |
cf745305 TK |
486 | rc = NULL; |
487 | goto CLEANUP; | |
488 | } | |
a8e1eeba MH |
489 | if ( (Ustrlen(dkim_private_key_expanded) == 0) || |
490 | (Ustrcmp(dkim_private_key_expanded,"0") == 0) || | |
491 | (Ustrcmp(dkim_private_key_expanded,"false") == 0) ) { | |
492 | /* don't sign, but no error */ | |
bc4bc4c5 | 493 | continue; |
a8e1eeba MH |
494 | } |
495 | ||
496 | if (dkim_private_key_expanded[0] == '/') { | |
497 | int privkey_fd = 0; | |
498 | /* Looks like a filename, load the private key. */ | |
499 | memset(big_buffer,0,big_buffer_size); | |
500 | privkey_fd = open(CS dkim_private_key_expanded,O_RDONLY); | |
501 | if (privkey_fd < 0) { | |
502 | log_write(0, LOG_MAIN|LOG_PANIC, "unable to open " | |
503 | "private key file for reading: %s", dkim_private_key_expanded); | |
504 | rc = NULL; | |
505 | goto CLEANUP; | |
506 | } | |
1ac6b2e7 JH |
507 | if (read(privkey_fd,big_buffer,(big_buffer_size-2)) < 0) { |
508 | log_write(0, LOG_MAIN|LOG_PANIC, "unable to read private key file: %s", | |
509 | dkim_private_key_expanded); | |
510 | rc = NULL; | |
511 | goto CLEANUP; | |
512 | } | |
a8e1eeba MH |
513 | (void)close(privkey_fd); |
514 | dkim_private_key_expanded = big_buffer; | |
515 | } | |
80a47a2c | 516 | |
a8e1eeba MH |
517 | ctx = pdkim_init_sign(PDKIM_INPUT_SMTP, |
518 | (char *)dkim_signing_domain, | |
519 | (char *)dkim_signing_selector, | |
520 | (char *)dkim_private_key_expanded | |
521 | ); | |
522 | ||
523 | pdkim_set_debug_stream(ctx,debug_file); | |
524 | ||
525 | pdkim_set_optional(ctx, | |
526 | (char *)dkim_sign_headers_expanded, | |
527 | NULL, | |
528 | pdkim_canon, | |
529 | pdkim_canon, | |
530 | -1, | |
531 | PDKIM_ALGO_RSA_SHA256, | |
532 | 0, | |
533 | 0); | |
534 | ||
bc4bc4c5 | 535 | lseek(dkim_fd, 0, SEEK_SET); |
a8e1eeba MH |
536 | while((sread = read(dkim_fd,&buf,4096)) > 0) { |
537 | if (pdkim_feed(ctx,buf,sread) != PDKIM_OK) { | |
538 | rc = NULL; | |
539 | goto CLEANUP; | |
540 | } | |
541 | } | |
542 | /* Handle failed read above. */ | |
543 | if (sread == -1) { | |
544 | debug_printf("DKIM: Error reading -K file.\n"); | |
545 | save_errno = errno; | |
80a47a2c TK |
546 | rc = NULL; |
547 | goto CLEANUP; | |
548 | } | |
80a47a2c | 549 | |
a8e1eeba MH |
550 | pdkim_rc = pdkim_feed_finish(ctx,&signature); |
551 | if (pdkim_rc != PDKIM_OK) { | |
552 | log_write(0, LOG_MAIN|LOG_PANIC, "DKIM: signing failed (RC %d)", pdkim_rc); | |
bc4bc4c5 | 553 | rc = NULL; |
a8e1eeba MH |
554 | goto CLEANUP; |
555 | } | |
80a47a2c | 556 | |
bc4bc4c5 PP |
557 | sigbuf = string_append(sigbuf, &sigsize, &sigptr, 2, |
558 | US signature->signature_header, | |
559 | US"\r\n"); | |
80a47a2c | 560 | |
80a47a2c | 561 | pdkim_free_ctx(ctx); |
a8e1eeba | 562 | ctx = NULL; |
80a47a2c | 563 | } |
a8e1eeba | 564 | |
bc4bc4c5 PP |
565 | if (sigbuf != NULL) { |
566 | sigbuf[sigptr] = '\0'; | |
567 | rc = sigbuf; | |
568 | } else | |
569 | rc = US""; | |
570 | ||
a8e1eeba MH |
571 | CLEANUP: |
572 | if (ctx != NULL) | |
573 | pdkim_free_ctx(ctx); | |
80a47a2c TK |
574 | store_pool = old_pool; |
575 | errno = save_errno; | |
576 | return rc; | |
93f2d376 | 577 | } |
80a47a2c TK |
578 | |
579 | #endif |