Commit | Line | Data |
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420a0d19 CE |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
2ea97746 | 5 | /* Copyright (c) Jeremy Harris 2014 - 2018 */ |
420a0d19 CE |
6 | |
7 | /* This file provides TLS/SSL support for Exim using the GnuTLS library, | |
8 | one of the available supported implementations. This file is #included into | |
9 | tls.c when USE_GNUTLS has been set. | |
10 | */ | |
11 | ||
12 | #include <gnutls/gnutls.h> | |
13 | /* needed for cert checks in verification and DN extraction: */ | |
14 | #include <gnutls/x509.h> | |
15 | /* needed to disable PKCS11 autoload unless requested */ | |
16 | #if GNUTLS_VERSION_NUMBER >= 0x020c00 | |
17 | # include <gnutls/pkcs11.h> | |
18 | #endif | |
19 | ||
20 | ||
21 | /***************************************************** | |
22 | * Export/import a certificate, binary/printable | |
23 | *****************************************************/ | |
24 | int | |
25 | tls_export_cert(uschar * buf, size_t buflen, void * cert) | |
26 | { | |
27 | size_t sz = buflen; | |
28 | void * reset_point = store_get(0); | |
29 | int fail; | |
2ea97746 | 30 | const uschar * cp; |
420a0d19 CE |
31 | |
32 | if ((fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert, | |
33 | GNUTLS_X509_FMT_PEM, buf, &sz))) | |
34 | { | |
35 | log_write(0, LOG_MAIN, "TLS error in certificate export: %s", | |
36 | gnutls_strerror(fail)); | |
37 | return 1; | |
38 | } | |
39 | if ((cp = string_printing(buf)) != buf) | |
40 | { | |
41 | Ustrncpy(buf, cp, buflen); | |
42 | if (buf[buflen-1]) | |
43 | fail = 1; | |
44 | } | |
45 | store_reset(reset_point); | |
46 | return fail; | |
47 | } | |
48 | ||
49 | int | |
50 | tls_import_cert(const uschar * buf, void ** cert) | |
51 | { | |
52 | void * reset_point = store_get(0); | |
53 | gnutls_datum_t datum; | |
2ea97746 | 54 | gnutls_x509_crt_t crt = *(gnutls_x509_crt_t *)cert; |
420a0d19 CE |
55 | int fail = 0; |
56 | ||
2ea97746 CE |
57 | if (crt) |
58 | gnutls_x509_crt_deinit(crt); | |
59 | else | |
60 | gnutls_global_init(); | |
61 | ||
420a0d19 CE |
62 | gnutls_x509_crt_init(&crt); |
63 | ||
64 | datum.data = string_unprinting(US buf); | |
65 | datum.size = Ustrlen(datum.data); | |
66 | if ((fail = gnutls_x509_crt_import(crt, &datum, GNUTLS_X509_FMT_PEM))) | |
67 | { | |
68 | log_write(0, LOG_MAIN, "TLS error in certificate import: %s", | |
69 | gnutls_strerror(fail)); | |
70 | fail = 1; | |
71 | } | |
72 | else | |
73 | *cert = (void *)crt; | |
74 | ||
75 | store_reset(reset_point); | |
76 | return fail; | |
77 | } | |
78 | ||
79 | void | |
2ea97746 | 80 | tls_free_cert(void ** cert) |
420a0d19 | 81 | { |
2ea97746 CE |
82 | gnutls_x509_crt_t crt = *(gnutls_x509_crt_t *)cert; |
83 | if (crt) | |
84 | { | |
85 | gnutls_x509_crt_deinit(crt); | |
86 | gnutls_global_deinit(); | |
87 | *cert = NULL; | |
88 | } | |
420a0d19 CE |
89 | } |
90 | ||
91 | /***************************************************** | |
92 | * Certificate field extraction routines | |
93 | *****************************************************/ | |
94 | ||
95 | /* First, some internal service functions */ | |
96 | ||
97 | static uschar * | |
98 | g_err(const char * tag, const char * from, int gnutls_err) | |
99 | { | |
100 | expand_string_message = string_sprintf("%s: %s fail: %s\n", | |
101 | from, tag, gnutls_strerror(gnutls_err)); | |
102 | return NULL; | |
103 | } | |
104 | ||
105 | ||
106 | static uschar * | |
107 | time_copy(time_t t, uschar * mod) | |
108 | { | |
109 | uschar * cp; | |
2ea97746 | 110 | size_t len = 32; |
420a0d19 CE |
111 | |
112 | if (mod && Ustrcmp(mod, "int") == 0) | |
113 | return string_sprintf("%u", (unsigned)t); | |
114 | ||
2ea97746 CE |
115 | cp = store_get(len); |
116 | if (f.timestamps_utc) | |
117 | { | |
118 | uschar * tz = to_tz(US"GMT0"); | |
119 | len = strftime(CS cp, len, "%b %e %T %Y %Z", gmtime(&t)); | |
120 | restore_tz(tz); | |
121 | } | |
122 | else | |
123 | len = strftime(CS cp, len, "%b %e %T %Y %Z", localtime(&t)); | |
420a0d19 CE |
124 | return len > 0 ? cp : NULL; |
125 | } | |
126 | ||
127 | ||
128 | /**/ | |
129 | /* Now the extractors, called from expand.c | |
130 | Arguments: | |
131 | cert The certificate | |
132 | mod Optional modifiers for the operator | |
133 | ||
134 | Return: | |
135 | Allocated string with extracted value | |
136 | */ | |
137 | ||
138 | uschar * | |
139 | tls_cert_issuer(void * cert, uschar * mod) | |
140 | { | |
141 | uschar * cp = NULL; | |
142 | int ret; | |
143 | size_t siz = 0; | |
144 | ||
2ea97746 | 145 | if ((ret = gnutls_x509_crt_get_issuer_dn(cert, CS cp, &siz)) |
420a0d19 CE |
146 | != GNUTLS_E_SHORT_MEMORY_BUFFER) |
147 | return g_err("gi0", __FUNCTION__, ret); | |
148 | ||
149 | cp = store_get(siz); | |
2ea97746 | 150 | if ((ret = gnutls_x509_crt_get_issuer_dn(cert, CS cp, &siz)) < 0) |
420a0d19 CE |
151 | return g_err("gi1", __FUNCTION__, ret); |
152 | ||
153 | return mod ? tls_field_from_dn(cp, mod) : cp; | |
154 | } | |
155 | ||
156 | uschar * | |
157 | tls_cert_not_after(void * cert, uschar * mod) | |
158 | { | |
159 | return time_copy( | |
160 | gnutls_x509_crt_get_expiration_time((gnutls_x509_crt_t)cert), | |
161 | mod); | |
162 | } | |
163 | ||
164 | uschar * | |
165 | tls_cert_not_before(void * cert, uschar * mod) | |
166 | { | |
167 | return time_copy( | |
168 | gnutls_x509_crt_get_activation_time((gnutls_x509_crt_t)cert), | |
169 | mod); | |
170 | } | |
171 | ||
172 | uschar * | |
173 | tls_cert_serial_number(void * cert, uschar * mod) | |
174 | { | |
175 | uschar bin[50], txt[150]; | |
176 | size_t sz = sizeof(bin); | |
177 | uschar * sp; | |
178 | uschar * dp; | |
179 | int ret; | |
180 | ||
181 | if ((ret = gnutls_x509_crt_get_serial((gnutls_x509_crt_t)cert, | |
182 | bin, &sz))) | |
183 | return g_err("gs0", __FUNCTION__, ret); | |
184 | ||
2ea97746 CE |
185 | for(dp = txt, sp = bin; sz; sz--) |
186 | dp += sprintf(CS dp, "%.2x", *sp++); | |
420a0d19 CE |
187 | for(sp = txt; sp[0]=='0' && sp[1]; ) sp++; /* leading zeroes */ |
188 | return string_copy(sp); | |
189 | } | |
190 | ||
191 | uschar * | |
192 | tls_cert_signature(void * cert, uschar * mod) | |
193 | { | |
2ea97746 | 194 | uschar * cp1 = NULL; |
420a0d19 CE |
195 | uschar * cp2; |
196 | uschar * cp3; | |
197 | size_t len = 0; | |
198 | int ret; | |
199 | ||
2ea97746 | 200 | if ((ret = gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len)) |
420a0d19 CE |
201 | != GNUTLS_E_SHORT_MEMORY_BUFFER) |
202 | return g_err("gs0", __FUNCTION__, ret); | |
203 | ||
204 | cp1 = store_get(len*4+1); | |
2ea97746 | 205 | if (gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len) != 0) |
420a0d19 CE |
206 | return g_err("gs1", __FUNCTION__, ret); |
207 | ||
2ea97746 CE |
208 | for(cp3 = cp2 = cp1+len; cp1 < cp2; cp1++) |
209 | cp3 += sprintf(CS cp3, "%.2x ", *cp1); | |
420a0d19 CE |
210 | cp3[-1]= '\0'; |
211 | ||
212 | return cp2; | |
213 | } | |
214 | ||
215 | uschar * | |
216 | tls_cert_signature_algorithm(void * cert, uschar * mod) | |
217 | { | |
218 | gnutls_sign_algorithm_t algo = | |
219 | gnutls_x509_crt_get_signature_algorithm((gnutls_x509_crt_t)cert); | |
2ea97746 | 220 | return algo < 0 ? NULL : string_copy(US gnutls_sign_get_name(algo)); |
420a0d19 CE |
221 | } |
222 | ||
223 | uschar * | |
224 | tls_cert_subject(void * cert, uschar * mod) | |
225 | { | |
226 | uschar * cp = NULL; | |
227 | int ret; | |
228 | size_t siz = 0; | |
229 | ||
2ea97746 | 230 | if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz)) |
420a0d19 CE |
231 | != GNUTLS_E_SHORT_MEMORY_BUFFER) |
232 | return g_err("gs0", __FUNCTION__, ret); | |
233 | ||
234 | cp = store_get(siz); | |
2ea97746 | 235 | if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz)) < 0) |
420a0d19 CE |
236 | return g_err("gs1", __FUNCTION__, ret); |
237 | ||
238 | return mod ? tls_field_from_dn(cp, mod) : cp; | |
239 | } | |
240 | ||
241 | uschar * | |
242 | tls_cert_version(void * cert, uschar * mod) | |
243 | { | |
244 | return string_sprintf("%d", gnutls_x509_crt_get_version(cert)); | |
245 | } | |
246 | ||
247 | uschar * | |
248 | tls_cert_ext_by_oid(void * cert, uschar * oid, int idx) | |
249 | { | |
250 | uschar * cp1 = NULL; | |
251 | uschar * cp2; | |
252 | uschar * cp3; | |
253 | size_t siz = 0; | |
254 | unsigned int crit; | |
255 | int ret; | |
256 | ||
257 | ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert, | |
2ea97746 | 258 | CS oid, idx, CS cp1, &siz, &crit); |
420a0d19 CE |
259 | if (ret != GNUTLS_E_SHORT_MEMORY_BUFFER) |
260 | return g_err("ge0", __FUNCTION__, ret); | |
261 | ||
262 | cp1 = store_get(siz*4 + 1); | |
263 | ||
264 | ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert, | |
2ea97746 | 265 | CS oid, idx, CS cp1, &siz, &crit); |
420a0d19 CE |
266 | if (ret < 0) |
267 | return g_err("ge1", __FUNCTION__, ret); | |
268 | ||
269 | /* binary data, DER encoded */ | |
270 | ||
271 | /* just dump for now */ | |
2ea97746 CE |
272 | for(cp3 = cp2 = cp1+siz; cp1 < cp2; cp1++) |
273 | cp3 += sprintf(CS cp3, "%.2x ", *cp1); | |
420a0d19 CE |
274 | cp3[-1]= '\0'; |
275 | ||
276 | return cp2; | |
277 | } | |
278 | ||
279 | uschar * | |
280 | tls_cert_subject_altname(void * cert, uschar * mod) | |
281 | { | |
2ea97746 | 282 | gstring * list = NULL; |
420a0d19 CE |
283 | int index; |
284 | size_t siz; | |
285 | int ret; | |
286 | uschar sep = '\n'; | |
287 | uschar * tag = US""; | |
288 | uschar * ele; | |
289 | int match = -1; | |
290 | ||
291 | while (mod) | |
292 | { | |
293 | if (*mod == '>' && *++mod) sep = *mod++; | |
294 | else if (Ustrcmp(mod, "dns")==0) { match = GNUTLS_SAN_DNSNAME; mod += 3; } | |
295 | else if (Ustrcmp(mod, "uri")==0) { match = GNUTLS_SAN_URI; mod += 3; } | |
296 | else if (Ustrcmp(mod, "mail")==0) { match = GNUTLS_SAN_RFC822NAME; mod += 4; } | |
297 | else continue; | |
298 | ||
299 | if (*mod++ != ',') | |
300 | break; | |
301 | } | |
302 | ||
303 | for(index = 0;; index++) | |
304 | { | |
305 | siz = 0; | |
306 | switch(ret = gnutls_x509_crt_get_subject_alt_name( | |
307 | (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL)) | |
308 | { | |
309 | case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE: | |
2ea97746 | 310 | return string_from_gstring(list); /* no more elements; normal exit */ |
420a0d19 CE |
311 | |
312 | case GNUTLS_E_SHORT_MEMORY_BUFFER: | |
313 | break; | |
314 | ||
315 | default: | |
316 | return g_err("gs0", __FUNCTION__, ret); | |
317 | } | |
318 | ||
319 | ele = store_get(siz+1); | |
320 | if ((ret = gnutls_x509_crt_get_subject_alt_name( | |
321 | (gnutls_x509_crt_t)cert, index, ele, &siz, NULL)) < 0) | |
322 | return g_err("gs1", __FUNCTION__, ret); | |
323 | ele[siz] = '\0'; | |
324 | ||
325 | if ( match != -1 && match != ret /* wrong type of SAN */ | |
326 | || Ustrlen(ele) != siz) /* contains a NUL */ | |
327 | continue; | |
328 | switch (ret) | |
329 | { | |
330 | case GNUTLS_SAN_DNSNAME: tag = US"DNS"; break; | |
2ea97746 | 331 | case GNUTLS_SAN_URI: tag = US"URI"; break; |
420a0d19 CE |
332 | case GNUTLS_SAN_RFC822NAME: tag = US"MAIL"; break; |
333 | default: continue; /* ignore unrecognised types */ | |
334 | } | |
2ea97746 | 335 | list = string_append_listele(list, sep, |
420a0d19 CE |
336 | match == -1 ? string_sprintf("%s=%s", tag, ele) : ele); |
337 | } | |
338 | /*NOTREACHED*/ | |
339 | } | |
340 | ||
341 | uschar * | |
342 | tls_cert_ocsp_uri(void * cert, uschar * mod) | |
343 | { | |
344 | #if GNUTLS_VERSION_NUMBER >= 0x030000 | |
345 | gnutls_datum_t uri; | |
346 | int ret; | |
347 | uschar sep = '\n'; | |
348 | int index; | |
2ea97746 | 349 | gstring * list = NULL; |
420a0d19 CE |
350 | |
351 | if (mod) | |
352 | if (*mod == '>' && *++mod) sep = *mod++; | |
353 | ||
354 | for(index = 0;; index++) | |
355 | { | |
356 | ret = gnutls_x509_crt_get_authority_info_access((gnutls_x509_crt_t)cert, | |
357 | index, GNUTLS_IA_OCSP_URI, &uri, NULL); | |
358 | ||
359 | if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) | |
2ea97746 | 360 | return string_from_gstring(list); |
420a0d19 CE |
361 | if (ret < 0) |
362 | return g_err("gai", __FUNCTION__, ret); | |
363 | ||
2ea97746 | 364 | list = string_append_listele_n(list, sep, uri.data, uri.size); |
420a0d19 CE |
365 | } |
366 | /*NOTREACHED*/ | |
367 | ||
368 | #else | |
369 | ||
2ea97746 | 370 | expand_string_message = |
420a0d19 CE |
371 | string_sprintf("%s: OCSP support with GnuTLS requires version 3.0.0\n", |
372 | __FUNCTION__); | |
373 | return NULL; | |
374 | ||
375 | #endif | |
376 | } | |
377 | ||
378 | uschar * | |
379 | tls_cert_crl_uri(void * cert, uschar * mod) | |
380 | { | |
381 | int ret; | |
382 | size_t siz; | |
383 | uschar sep = '\n'; | |
384 | int index; | |
2ea97746 | 385 | gstring * list = NULL; |
420a0d19 CE |
386 | uschar * ele; |
387 | ||
388 | if (mod) | |
389 | if (*mod == '>' && *++mod) sep = *mod++; | |
390 | ||
391 | for(index = 0;; index++) | |
392 | { | |
393 | siz = 0; | |
394 | switch(ret = gnutls_x509_crt_get_crl_dist_points( | |
395 | (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL, NULL)) | |
396 | { | |
397 | case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE: | |
2ea97746 | 398 | return string_from_gstring(list); |
420a0d19 CE |
399 | case GNUTLS_E_SHORT_MEMORY_BUFFER: |
400 | break; | |
401 | default: | |
402 | return g_err("gc0", __FUNCTION__, ret); | |
403 | } | |
404 | ||
2ea97746 | 405 | ele = store_get(siz); |
420a0d19 CE |
406 | if ((ret = gnutls_x509_crt_get_crl_dist_points( |
407 | (gnutls_x509_crt_t)cert, index, ele, &siz, NULL, NULL)) < 0) | |
408 | return g_err("gc1", __FUNCTION__, ret); | |
409 | ||
2ea97746 | 410 | list = string_append_listele_n(list, sep, ele, siz); |
420a0d19 CE |
411 | } |
412 | /*NOTREACHED*/ | |
413 | } | |
414 | ||
415 | ||
416 | /***************************************************** | |
417 | * Certificate operator routines | |
418 | *****************************************************/ | |
2ea97746 CE |
419 | uschar * |
420 | tls_cert_der_b64(void * cert) | |
421 | { | |
422 | size_t len = 0; | |
423 | uschar * cp = NULL; | |
424 | int fail; | |
425 | ||
426 | if ( (fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert, | |
427 | GNUTLS_X509_FMT_DER, cp, &len)) != GNUTLS_E_SHORT_MEMORY_BUFFER | |
428 | || !(cp = store_get((int)len)) | |
429 | || (fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert, | |
430 | GNUTLS_X509_FMT_DER, cp, &len)) | |
431 | ) | |
432 | { | |
433 | log_write(0, LOG_MAIN, "TLS error in certificate export: %s", | |
434 | gnutls_strerror(fail)); | |
435 | return NULL; | |
436 | } | |
437 | return b64encode(cp, (int)len); | |
438 | } | |
439 | ||
440 | ||
420a0d19 CE |
441 | static uschar * |
442 | fingerprint(gnutls_x509_crt_t cert, gnutls_digest_algorithm_t algo) | |
443 | { | |
444 | int ret; | |
445 | size_t siz = 0; | |
446 | uschar * cp; | |
447 | uschar * cp2; | |
448 | uschar * cp3; | |
449 | ||
450 | if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, NULL, &siz)) | |
451 | != GNUTLS_E_SHORT_MEMORY_BUFFER) | |
452 | return g_err("gf0", __FUNCTION__, ret); | |
453 | ||
454 | cp = store_get(siz*3+1); | |
455 | if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, cp, &siz)) < 0) | |
456 | return g_err("gf1", __FUNCTION__, ret); | |
457 | ||
2ea97746 CE |
458 | for (cp3 = cp2 = cp+siz; cp < cp2; cp++) |
459 | cp3 += sprintf(CS cp3, "%02X", *cp); | |
420a0d19 CE |
460 | return cp2; |
461 | } | |
462 | ||
463 | ||
464 | uschar * | |
465 | tls_cert_fprt_md5(void * cert) | |
466 | { | |
467 | return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_MD5); | |
468 | } | |
469 | ||
470 | uschar * | |
471 | tls_cert_fprt_sha1(void * cert) | |
472 | { | |
473 | return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA1); | |
474 | } | |
475 | ||
476 | uschar * | |
477 | tls_cert_fprt_sha256(void * cert) | |
478 | { | |
479 | return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA256); | |
480 | } | |
481 | ||
482 | ||
483 | /* vi: aw ai sw=2 | |
484 | */ | |
485 | /* End of tlscert-gnu.c */ |