Commit | Line | Data |
---|---|---|
9d1c15ef JH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
5 | /* Copyright (c) Jeremy Harris 2014 */ | |
6 | ||
7 | /* This module provides TLS (aka SSL) support for Exim using the OpenSSL | |
8 | library. It is #included into the tls.c file when that library is used. | |
9 | */ | |
10 | ||
11 | ||
12 | /* Heading stuff */ | |
13 | ||
14 | #include <openssl/lhash.h> | |
15 | #include <openssl/ssl.h> | |
16 | #include <openssl/err.h> | |
17 | #include <openssl/rand.h> | |
51424d08 | 18 | #include <openssl/x509v3.h> |
9d1c15ef JH |
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 | BIO * bp = BIO_new(BIO_s_mem()); | |
28 | int fail; | |
29 | ||
30 | if ((fail = PEM_write_bio_X509(bp, (X509 *)cert) ? 0 : 1)) | |
31 | log_write(0, LOG_MAIN, "TLS error in certificate export: %s", | |
32 | ERR_error_string(ERR_get_error(), NULL)); | |
33 | else | |
34 | { | |
35 | char * cp = CS buf; | |
36 | int n; | |
37 | buflen -= 2; | |
38 | for(;;) | |
39 | { | |
40 | if ((n = BIO_gets(bp, cp, (int)buflen)) <= 0) break; | |
41 | cp += n+1; | |
42 | buflen -= n+1; | |
43 | cp[-2] = '\\'; cp[-1] = 'n'; /* newline->"\n" */ | |
44 | } /* compat with string_printing() */ | |
45 | *cp = '\0'; | |
46 | } | |
47 | ||
48 | BIO_free(bp); | |
49 | return fail; | |
50 | } | |
51 | ||
52 | int | |
53 | tls_import_cert(const uschar * buf, void ** cert) | |
54 | { | |
55 | void * reset_point = store_get(0); | |
56 | const uschar * cp = string_unprinting(US buf); | |
57 | BIO * bp; | |
58 | X509 * x; | |
c03fae8a | 59 | int fail = 0; |
9d1c15ef JH |
60 | |
61 | bp = BIO_new_mem_buf(US cp, -1); | |
c03fae8a JH |
62 | if (!(x = PEM_read_bio_X509(bp, NULL, 0, NULL))) |
63 | { | |
64 | log_write(0, LOG_MAIN, "TLS error in certificate import: %s", | |
65 | ERR_error_string(ERR_get_error(), NULL)); | |
9d1c15ef | 66 | fail = 1; |
c03fae8a | 67 | } |
9d1c15ef JH |
68 | else |
69 | *cert = (void *)x; | |
70 | BIO_free(bp); | |
71 | store_reset(reset_point); | |
72 | return fail; | |
73 | } | |
74 | ||
75 | void | |
76 | tls_free_cert(void * cert) | |
77 | { | |
78 | X509_free((X509 *)cert); | |
79 | } | |
80 | ||
c03fae8a | 81 | |
9d1c15ef JH |
82 | /***************************************************** |
83 | * Certificate field extraction routines | |
84 | *****************************************************/ | |
c03fae8a JH |
85 | |
86 | /* First, some internal service functions */ | |
87 | ||
88 | static uschar * | |
89 | badalloc(void) | |
90 | { | |
91 | expand_string_message = US"allocation failure"; | |
92 | return NULL; | |
93 | } | |
94 | ||
9d1c15ef JH |
95 | static uschar * |
96 | bio_string_copy(BIO * bp, int len) | |
97 | { | |
e3dd1d67 | 98 | uschar * cp = US""; |
9d1c15ef JH |
99 | len = len > 0 ? (int) BIO_get_mem_data(bp, &cp) : 0; |
100 | cp = string_copyn(cp, len); | |
101 | BIO_free(bp); | |
102 | return cp; | |
103 | } | |
104 | ||
105 | static uschar * | |
e9477a08 | 106 | asn1_time_copy(const ASN1_TIME * asntime, uschar * mod) |
9d1c15ef | 107 | { |
e9477a08 | 108 | uschar * s = NULL; |
9d1c15ef | 109 | BIO * bp = BIO_new(BIO_s_mem()); |
c03fae8a JH |
110 | int len; |
111 | ||
e9477a08 JH |
112 | if (!bp) |
113 | return badalloc(); | |
114 | len = ASN1_TIME_print(bp, asntime); | |
115 | len = len > 0 ? (int) BIO_get_mem_data(bp, &s) : 0; | |
c03fae8a | 116 | |
e9477a08 JH |
117 | if (mod && Ustrcmp(mod, "raw") == 0) /* native ASN */ |
118 | s = string_copyn(s, len); | |
119 | else | |
120 | { | |
121 | struct tm tm; | |
122 | struct tm * tm_p = &tm; | |
123 | BOOL mod_tz; | |
45500060 | 124 | uschar * tz = to_tz(US"GMT0"); /* need to call strptime with baseline TZ */ |
e9477a08 JH |
125 | |
126 | /* Parse OpenSSL ASN1_TIME_print output. A shame there seems to | |
127 | be no other interface for the times. | |
128 | */ | |
129 | ||
130 | /*XXX %Z might be glibc-specific? Solaris has it, at least*/ | |
131 | /*XXX should we switch to POSIX locale for this? */ | |
132 | tm.tm_isdst = 0; | |
133 | if (!strptime(CCS s, "%b %e %T %Y %Z", &tm)) | |
134 | expand_string_message = US"failed time conversion"; | |
135 | ||
136 | else | |
137 | { | |
138 | time_t t = mktime(&tm); /* make the tm self-consistent */ | |
139 | ||
140 | if (mod && Ustrcmp(mod, "int") == 0) /* seconds since epoch */ | |
141 | s = string_sprintf("%u", t); | |
142 | ||
143 | else | |
144 | { | |
145 | if (!timestamps_utc) /* decoded string in local TZ */ | |
146 | { /* shift to local TZ */ | |
147 | restore_tz(tz); | |
148 | mod_tz = FALSE; | |
149 | tm_p = localtime(&t); | |
150 | } | |
151 | /* "utc" is default, and rfc5280 says cert times should be Zulu */ | |
152 | ||
153 | /* convert to string in our format */ | |
154 | len = 32; | |
155 | s = store_get(len); | |
156 | strftime(CS s, (size_t)len, "%b %e %T %Y %z", tm_p); | |
157 | } | |
158 | } | |
159 | ||
160 | if (mod_tz); | |
161 | restore_tz(tz); | |
162 | } | |
163 | BIO_free(bp); | |
164 | return s; | |
9d1c15ef JH |
165 | } |
166 | ||
167 | static uschar * | |
168 | x509_name_copy(X509_NAME * name) | |
169 | { | |
170 | BIO * bp = BIO_new(BIO_s_mem()); | |
c03fae8a JH |
171 | int len_good; |
172 | ||
173 | if (!bp) return badalloc(); | |
174 | ||
175 | len_good = | |
9d1c15ef JH |
176 | X509_NAME_print_ex(bp, name, 0, XN_FLAG_RFC2253) >= 0 |
177 | ? 1 : 0; | |
178 | return bio_string_copy(bp, len_good); | |
179 | } | |
180 | ||
181 | /**/ | |
c03fae8a JH |
182 | /* Now the extractors, called from expand.c |
183 | Arguments: | |
184 | cert The certificate | |
185 | mod Optional modifiers for the operator | |
186 | ||
187 | Return: | |
188 | Allocated string with extracted value | |
189 | */ | |
9d1c15ef JH |
190 | |
191 | uschar * | |
9e4dddbd | 192 | tls_cert_issuer(void * cert, uschar * mod) |
9d1c15ef | 193 | { |
812a6045 JH |
194 | uschar * cp = x509_name_copy(X509_get_issuer_name((X509 *)cert)); |
195 | return mod ? tls_field_from_dn(cp, mod) : cp; | |
9d1c15ef JH |
196 | } |
197 | ||
198 | uschar * | |
9e4dddbd | 199 | tls_cert_not_before(void * cert, uschar * mod) |
9d1c15ef | 200 | { |
25ba2544 | 201 | return asn1_time_copy(X509_get_notBefore((X509 *)cert), mod); |
9d1c15ef JH |
202 | } |
203 | ||
204 | uschar * | |
9e4dddbd | 205 | tls_cert_not_after(void * cert, uschar * mod) |
9d1c15ef | 206 | { |
25ba2544 | 207 | return asn1_time_copy(X509_get_notAfter((X509 *)cert), mod); |
9d1c15ef JH |
208 | } |
209 | ||
210 | uschar * | |
9e4dddbd | 211 | tls_cert_serial_number(void * cert, uschar * mod) |
9d1c15ef JH |
212 | { |
213 | uschar txt[256]; | |
214 | BIO * bp = BIO_new(BIO_s_mem()); | |
c03fae8a | 215 | int len; |
9d1c15ef | 216 | |
c03fae8a JH |
217 | if (!bp) return badalloc(); |
218 | ||
219 | len = i2a_ASN1_INTEGER(bp, X509_get_serialNumber((X509 *)cert)); | |
9d1c15ef JH |
220 | if (len < sizeof(txt)) |
221 | BIO_read(bp, txt, len); | |
222 | else | |
223 | len = 0; | |
224 | BIO_free(bp); | |
225 | return string_copynlc(txt, len); /* lowercase */ | |
226 | } | |
227 | ||
228 | uschar * | |
9e4dddbd | 229 | tls_cert_signature(void * cert, uschar * mod) |
9d1c15ef | 230 | { |
9d1c15ef | 231 | uschar * cp = NULL; |
c03fae8a JH |
232 | BIO * bp = BIO_new(BIO_s_mem()); |
233 | ||
234 | if (!bp) return badalloc(); | |
9d1c15ef JH |
235 | |
236 | if (X509_print_ex(bp, (X509 *)cert, 0, | |
237 | X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL | | |
238 | X509_FLAG_NO_SIGNAME | X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY | | |
239 | X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS | | |
240 | /* X509_FLAG_NO_SIGDUMP is the missing one */ | |
241 | X509_FLAG_NO_AUX) == 1) | |
242 | { | |
243 | long len = BIO_get_mem_data(bp, &cp); | |
315e209a JH |
244 | |
245 | /* Strip leading "Signature Algorithm" line */ | |
246 | while (*cp && *cp != '\n') { cp++; len--; } | |
247 | ||
248 | cp = string_copyn(cp+1, len-1); | |
9d1c15ef JH |
249 | } |
250 | BIO_free(bp); | |
251 | return cp; | |
252 | } | |
253 | ||
254 | uschar * | |
9e4dddbd | 255 | tls_cert_signature_algorithm(void * cert, uschar * mod) |
9d1c15ef | 256 | { |
315e209a JH |
257 | uschar * cp = NULL; |
258 | BIO * bp = BIO_new(BIO_s_mem()); | |
259 | ||
260 | if (!bp) return badalloc(); | |
261 | ||
262 | if (X509_print_ex(bp, (X509 *)cert, 0, | |
263 | X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL | | |
264 | /* X509_FLAG_NO_SIGNAME is the missing one */ | |
265 | X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY | | |
266 | X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS | | |
267 | X509_FLAG_NO_SIGDUMP | X509_FLAG_NO_AUX) == 1) | |
268 | { | |
269 | long len = BIO_get_mem_data(bp, &cp); | |
270 | ||
271 | /* Strip leading " Signature Algorithm: " and trailing newline */ | |
272 | while (*cp && *cp != ':') { cp++; len--; } | |
273 | do { cp++; len--; } while (*cp && *cp == ' '); | |
274 | if (cp[len-1] == '\n') len--; | |
275 | ||
276 | cp = string_copyn(cp, len); | |
277 | } | |
278 | BIO_free(bp); | |
279 | return cp; | |
9d1c15ef JH |
280 | } |
281 | ||
282 | uschar * | |
9e4dddbd | 283 | tls_cert_subject(void * cert, uschar * mod) |
9d1c15ef | 284 | { |
812a6045 JH |
285 | uschar * cp = x509_name_copy(X509_get_subject_name((X509 *)cert)); |
286 | return mod ? tls_field_from_dn(cp, mod) : cp; | |
9d1c15ef JH |
287 | } |
288 | ||
289 | uschar * | |
9e4dddbd | 290 | tls_cert_version(void * cert, uschar * mod) |
9d1c15ef JH |
291 | { |
292 | return string_sprintf("%d", X509_get_version((X509 *)cert)); | |
293 | } | |
294 | ||
295 | uschar * | |
296 | tls_cert_ext_by_oid(void * cert, uschar * oid, int idx) | |
297 | { | |
e3dd1d67 | 298 | int nid = OBJ_create(CS oid, "", ""); |
9d1c15ef JH |
299 | int nidx = X509_get_ext_by_NID((X509 *)cert, nid, idx); |
300 | X509_EXTENSION * ex = X509_get_ext((X509 *)cert, nidx); | |
301 | ASN1_OCTET_STRING * adata = X509_EXTENSION_get_data(ex); | |
302 | BIO * bp = BIO_new(BIO_s_mem()); | |
303 | long len; | |
304 | uschar * cp1; | |
305 | uschar * cp2; | |
306 | uschar * cp3; | |
307 | ||
c03fae8a JH |
308 | if (!bp) return badalloc(); |
309 | ||
9d1c15ef JH |
310 | M_ASN1_OCTET_STRING_print(bp, adata); |
311 | /* binary data, DER encoded */ | |
312 | ||
313 | /* just dump for now */ | |
314 | len = BIO_get_mem_data(bp, &cp1); | |
315 | cp3 = cp2 = store_get(len*3+1); | |
316 | ||
317 | while(len) | |
318 | { | |
e3dd1d67 | 319 | sprintf(CS cp2, "%.2x ", *cp1++); |
9d1c15ef JH |
320 | cp2 += 3; |
321 | len--; | |
322 | } | |
323 | cp2[-1] = '\0'; | |
324 | ||
325 | return cp3; | |
326 | } | |
327 | ||
328 | uschar * | |
9e4dddbd | 329 | tls_cert_subject_altname(void * cert, uschar * mod) |
9d1c15ef | 330 | { |
9e4dddbd | 331 | uschar * list = NULL; |
9d1c15ef JH |
332 | STACK_OF(GENERAL_NAME) * san = (STACK_OF(GENERAL_NAME) *) |
333 | X509_get_ext_d2i((X509 *)cert, NID_subject_alt_name, NULL, NULL); | |
9e4dddbd JH |
334 | uschar sep = '\n'; |
335 | uschar * tag = US""; | |
336 | uschar * ele; | |
337 | int match = -1; | |
e51c7be2 | 338 | int len; |
9d1c15ef JH |
339 | |
340 | if (!san) return NULL; | |
341 | ||
9e4dddbd JH |
342 | while (mod) |
343 | { | |
344 | if (*mod == '>' && *++mod) sep = *mod++; | |
345 | else if (Ustrcmp(mod, "dns")==0) { match = GEN_DNS; mod += 3; } | |
346 | else if (Ustrcmp(mod, "uri")==0) { match = GEN_URI; mod += 3; } | |
347 | else if (Ustrcmp(mod, "mail")==0) { match = GEN_EMAIL; mod += 4; } | |
348 | else continue; | |
349 | ||
350 | if (*mod++ != ',') | |
351 | break; | |
352 | } | |
353 | ||
9d1c15ef JH |
354 | while (sk_GENERAL_NAME_num(san) > 0) |
355 | { | |
356 | GENERAL_NAME * namePart = sk_GENERAL_NAME_pop(san); | |
9e4dddbd JH |
357 | if (match != -1 && match != namePart->type) |
358 | continue; | |
9d1c15ef JH |
359 | switch (namePart->type) |
360 | { | |
9e4dddbd JH |
361 | case GEN_DNS: |
362 | tag = US"DNS"; | |
363 | ele = ASN1_STRING_data(namePart->d.dNSName); | |
e51c7be2 | 364 | len = ASN1_STRING_length(namePart->d.dNSName); |
9e4dddbd | 365 | break; |
9d1c15ef | 366 | case GEN_URI: |
9e4dddbd JH |
367 | tag = US"URI"; |
368 | ele = ASN1_STRING_data(namePart->d.uniformResourceIdentifier); | |
e51c7be2 | 369 | len = ASN1_STRING_length(namePart->d.uniformResourceIdentifier); |
9e4dddbd | 370 | break; |
9d1c15ef | 371 | case GEN_EMAIL: |
9e4dddbd JH |
372 | tag = US"MAIL"; |
373 | ele = ASN1_STRING_data(namePart->d.rfc822Name); | |
e51c7be2 | 374 | len = ASN1_STRING_length(namePart->d.rfc822Name); |
9e4dddbd | 375 | break; |
9d1c15ef | 376 | default: |
9e4dddbd | 377 | continue; /* ignore unrecognised types */ |
9d1c15ef | 378 | } |
e51c7be2 JH |
379 | if (ele[len]) /* not nul-terminated */ |
380 | ele = string_copyn(ele, len); | |
381 | ||
9acf6b94 | 382 | if (Ustrlen(ele) == len) /* ignore any with embedded nul */ |
e51c7be2 | 383 | list = string_append_listele(list, sep, |
9e4dddbd | 384 | match == -1 ? string_sprintf("%s=%s", tag, ele) : ele); |
9d1c15ef JH |
385 | } |
386 | ||
9e4dddbd JH |
387 | sk_GENERAL_NAME_free(san); |
388 | return list; | |
9d1c15ef JH |
389 | } |
390 | ||
391 | uschar * | |
9e4dddbd | 392 | tls_cert_ocsp_uri(void * cert, uschar * mod) |
9d1c15ef JH |
393 | { |
394 | STACK_OF(ACCESS_DESCRIPTION) * ads = (STACK_OF(ACCESS_DESCRIPTION) *) | |
395 | X509_get_ext_d2i((X509 *)cert, NID_info_access, NULL, NULL); | |
396 | int adsnum = sk_ACCESS_DESCRIPTION_num(ads); | |
397 | int i; | |
9e4dddbd JH |
398 | uschar sep = '\n'; |
399 | uschar * list = NULL; | |
400 | ||
401 | if (mod) | |
402 | if (*mod == '>' && *++mod) sep = *mod++; | |
9d1c15ef JH |
403 | |
404 | for (i = 0; i < adsnum; i++) | |
405 | { | |
406 | ACCESS_DESCRIPTION * ad = sk_ACCESS_DESCRIPTION_value(ads, i); | |
407 | ||
408 | if (ad && OBJ_obj2nid(ad->method) == NID_ad_OCSP) | |
9e4dddbd JH |
409 | list = string_append_listele(list, sep, |
410 | ASN1_STRING_data(ad->location->d.ia5)); | |
9d1c15ef | 411 | } |
9e4dddbd | 412 | return list; |
9d1c15ef JH |
413 | } |
414 | ||
415 | uschar * | |
9e4dddbd | 416 | tls_cert_crl_uri(void * cert, uschar * mod) |
9d1c15ef JH |
417 | { |
418 | STACK_OF(DIST_POINT) * dps = (STACK_OF(DIST_POINT) *) | |
419 | X509_get_ext_d2i((X509 *)cert, NID_crl_distribution_points, | |
420 | NULL, NULL); | |
421 | DIST_POINT * dp; | |
422 | int dpsnum = sk_DIST_POINT_num(dps); | |
423 | int i; | |
9e4dddbd JH |
424 | uschar sep = '\n'; |
425 | uschar * list = NULL; | |
426 | ||
427 | if (mod) | |
428 | if (*mod == '>' && *++mod) sep = *mod++; | |
9d1c15ef JH |
429 | |
430 | if (dps) for (i = 0; i < dpsnum; i++) | |
431 | if ((dp = sk_DIST_POINT_value(dps, i))) | |
432 | { | |
433 | STACK_OF(GENERAL_NAME) * names = dp->distpoint->name.fullname; | |
434 | GENERAL_NAME * np; | |
435 | int nnum = sk_GENERAL_NAME_num(names); | |
436 | int j; | |
437 | ||
438 | for (j = 0; j < nnum; j++) | |
439 | if ( (np = sk_GENERAL_NAME_value(names, j)) | |
440 | && np->type == GEN_URI | |
441 | ) | |
9e4dddbd JH |
442 | list = string_append_listele(list, sep, |
443 | ASN1_STRING_data(np->d.uniformResourceIdentifier)); | |
9d1c15ef | 444 | } |
9e4dddbd | 445 | return list; |
9d1c15ef JH |
446 | } |
447 | ||
6a8a60e0 JH |
448 | |
449 | ||
450 | /***************************************************** | |
451 | * Certificate operator routines | |
452 | *****************************************************/ | |
453 | static uschar * | |
454 | fingerprint(X509 * cert, const EVP_MD * fdig) | |
455 | { | |
456 | int j; | |
457 | unsigned int n; | |
458 | uschar md[EVP_MAX_MD_SIZE]; | |
459 | uschar * cp; | |
460 | ||
461 | if (!X509_digest(cert,fdig,md,&n)) | |
462 | { | |
463 | expand_string_message = US"tls_cert_fprt: out of mem\n"; | |
464 | return NULL; | |
465 | } | |
466 | cp = store_get(n*2+1); | |
e3dd1d67 | 467 | for (j = 0; j < (int)n; j++) sprintf(CS cp+2*j, "%02X", md[j]); |
6a8a60e0 JH |
468 | return(cp); |
469 | } | |
470 | ||
471 | uschar * | |
472 | tls_cert_fprt_md5(void * cert) | |
473 | { | |
474 | return fingerprint((X509 *)cert, EVP_md5()); | |
475 | } | |
476 | ||
477 | uschar * | |
478 | tls_cert_fprt_sha1(void * cert) | |
479 | { | |
480 | return fingerprint((X509 *)cert, EVP_sha1()); | |
481 | } | |
482 | ||
9ef9101c JH |
483 | uschar * |
484 | tls_cert_fprt_sha256(void * cert) | |
485 | { | |
486 | return fingerprint((X509 *)cert, EVP_sha256()); | |
487 | } | |
488 | ||
6a8a60e0 | 489 | |
9d1c15ef JH |
490 | /* vi: aw ai sw=2 |
491 | */ | |
492 | /* End of tlscert-openssl.c */ |