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