Add $smtp_command_history variable
[exim.git] / src / src / tlscert-openssl.c
CommitLineData
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
80fea873 5/* Copyright (c) Jeremy Harris 2014 - 2016 */
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6
7/* This module provides TLS (aka SSL) support for Exim using the OpenSSL
8library. 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 19
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20#if OPENSSL_VERSION_NUMBER >= 0x10100000L
21# define EXIM_HAVE_ASN1_MACROS
22#endif
23
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24
25/*****************************************************
26* Export/import a certificate, binary/printable
27*****************************************************/
28int
29tls_export_cert(uschar * buf, size_t buflen, void * cert)
30{
31BIO * bp = BIO_new(BIO_s_mem());
32int fail;
33
34if ((fail = PEM_write_bio_X509(bp, (X509 *)cert) ? 0 : 1))
35 log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
36 ERR_error_string(ERR_get_error(), NULL));
37else
38 {
39 char * cp = CS buf;
40 int n;
41 buflen -= 2;
42 for(;;)
43 {
44 if ((n = BIO_gets(bp, cp, (int)buflen)) <= 0) break;
45 cp += n+1;
46 buflen -= n+1;
47 cp[-2] = '\\'; cp[-1] = 'n'; /* newline->"\n" */
48 } /* compat with string_printing() */
49 *cp = '\0';
50 }
51
52BIO_free(bp);
53return fail;
54}
55
56int
57tls_import_cert(const uschar * buf, void ** cert)
58{
59void * reset_point = store_get(0);
60const uschar * cp = string_unprinting(US buf);
61BIO * bp;
152e7604 62X509 * x = *(X509 **)cert;
c03fae8a 63int fail = 0;
9d1c15ef 64
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65if (x) X509_free(x);
66
9d1c15ef 67bp = BIO_new_mem_buf(US cp, -1);
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68if (!(x = PEM_read_bio_X509(bp, NULL, 0, NULL)))
69 {
70 log_write(0, LOG_MAIN, "TLS error in certificate import: %s",
71 ERR_error_string(ERR_get_error(), NULL));
9d1c15ef 72 fail = 1;
c03fae8a 73 }
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74else
75 *cert = (void *)x;
76BIO_free(bp);
77store_reset(reset_point);
78return fail;
79}
80
81void
790fbb71 82tls_free_cert(void ** cert)
9d1c15ef 83{
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84X509 * x = *(X509 **)cert;
85if (x)
86 {
87 X509_free(x);
88 *cert = NULL;
89 }
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90}
91
c03fae8a 92
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93/*****************************************************
94* Certificate field extraction routines
95*****************************************************/
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96
97/* First, some internal service functions */
98
99static uschar *
100badalloc(void)
101{
102expand_string_message = US"allocation failure";
103return NULL;
104}
105
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106static uschar *
107bio_string_copy(BIO * bp, int len)
108{
e3dd1d67 109uschar * cp = US"";
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110len = len > 0 ? (int) BIO_get_mem_data(bp, &cp) : 0;
111cp = string_copyn(cp, len);
112BIO_free(bp);
113return cp;
114}
115
116static uschar *
e9477a08 117asn1_time_copy(const ASN1_TIME * asntime, uschar * mod)
9d1c15ef 118{
e9477a08 119uschar * s = NULL;
9d1c15ef 120BIO * bp = BIO_new(BIO_s_mem());
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121int len;
122
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123if (!bp)
124 return badalloc();
125len = ASN1_TIME_print(bp, asntime);
d4ff61d1 126len = len > 0 ? (int) BIO_get_mem_data(bp, CSS &s) : 0;
c03fae8a 127
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128if (mod && Ustrcmp(mod, "raw") == 0) /* native ASN */
129 s = string_copyn(s, len);
130else
131 {
132 struct tm tm;
133 struct tm * tm_p = &tm;
755762fd 134 BOOL mod_tz = TRUE;
45500060 135 uschar * tz = to_tz(US"GMT0"); /* need to call strptime with baseline TZ */
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136
137 /* Parse OpenSSL ASN1_TIME_print output. A shame there seems to
138 be no other interface for the times.
139 */
140
141 /*XXX %Z might be glibc-specific? Solaris has it, at least*/
142 /*XXX should we switch to POSIX locale for this? */
143 tm.tm_isdst = 0;
d4ff61d1 144 if (!len || !strptime(CCS s, "%b %e %T %Y %Z", &tm))
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145 expand_string_message = US"failed time conversion";
146
147 else
148 {
149 time_t t = mktime(&tm); /* make the tm self-consistent */
150
151 if (mod && Ustrcmp(mod, "int") == 0) /* seconds since epoch */
152 s = string_sprintf("%u", t);
153
154 else
155 {
156 if (!timestamps_utc) /* decoded string in local TZ */
157 { /* shift to local TZ */
158 restore_tz(tz);
159 mod_tz = FALSE;
160 tm_p = localtime(&t);
161 }
162 /* "utc" is default, and rfc5280 says cert times should be Zulu */
163
164 /* convert to string in our format */
165 len = 32;
166 s = store_get(len);
167 strftime(CS s, (size_t)len, "%b %e %T %Y %z", tm_p);
168 }
169 }
170
755762fd 171 if (mod_tz)
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172 restore_tz(tz);
173 }
174BIO_free(bp);
175return s;
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176}
177
178static uschar *
179x509_name_copy(X509_NAME * name)
180{
181BIO * bp = BIO_new(BIO_s_mem());
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182int len_good;
183
184if (!bp) return badalloc();
185
186len_good =
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187 X509_NAME_print_ex(bp, name, 0, XN_FLAG_RFC2253) >= 0
188 ? 1 : 0;
189return bio_string_copy(bp, len_good);
190}
191
192/**/
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193/* Now the extractors, called from expand.c
194Arguments:
195 cert The certificate
196 mod Optional modifiers for the operator
197
198Return:
199 Allocated string with extracted value
200*/
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201
202uschar *
9e4dddbd 203tls_cert_issuer(void * cert, uschar * mod)
9d1c15ef 204{
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205uschar * cp = x509_name_copy(X509_get_issuer_name((X509 *)cert));
206return mod ? tls_field_from_dn(cp, mod) : cp;
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207}
208
209uschar *
9e4dddbd 210tls_cert_not_before(void * cert, uschar * mod)
9d1c15ef 211{
25ba2544 212return asn1_time_copy(X509_get_notBefore((X509 *)cert), mod);
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213}
214
215uschar *
9e4dddbd 216tls_cert_not_after(void * cert, uschar * mod)
9d1c15ef 217{
25ba2544 218return asn1_time_copy(X509_get_notAfter((X509 *)cert), mod);
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219}
220
221uschar *
9e4dddbd 222tls_cert_serial_number(void * cert, uschar * mod)
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223{
224uschar txt[256];
225BIO * bp = BIO_new(BIO_s_mem());
c03fae8a 226int len;
9d1c15ef 227
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228if (!bp) return badalloc();
229
230len = i2a_ASN1_INTEGER(bp, X509_get_serialNumber((X509 *)cert));
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231if (len < sizeof(txt))
232 BIO_read(bp, txt, len);
233else
234 len = 0;
235BIO_free(bp);
236return string_copynlc(txt, len); /* lowercase */
237}
238
239uschar *
9e4dddbd 240tls_cert_signature(void * cert, uschar * mod)
9d1c15ef 241{
9d1c15ef 242uschar * cp = NULL;
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243BIO * bp = BIO_new(BIO_s_mem());
244
245if (!bp) return badalloc();
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246
247if (X509_print_ex(bp, (X509 *)cert, 0,
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248 X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL |
249 X509_FLAG_NO_SIGNAME | X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY |
250 X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS |
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251 /* X509_FLAG_NO_SIGDUMP is the missing one */
252 X509_FLAG_NO_AUX) == 1)
253 {
254 long len = BIO_get_mem_data(bp, &cp);
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255
256 /* Strip leading "Signature Algorithm" line */
257 while (*cp && *cp != '\n') { cp++; len--; }
258
259 cp = string_copyn(cp+1, len-1);
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260 }
261BIO_free(bp);
262return cp;
263}
264
265uschar *
9e4dddbd 266tls_cert_signature_algorithm(void * cert, uschar * mod)
9d1c15ef 267{
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268uschar * cp = NULL;
269BIO * bp = BIO_new(BIO_s_mem());
270
271if (!bp) return badalloc();
272
273if (X509_print_ex(bp, (X509 *)cert, 0,
94431adb 274 X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL |
315e209a 275 /* X509_FLAG_NO_SIGNAME is the missing one */
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276 X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY |
277 X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS |
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278 X509_FLAG_NO_SIGDUMP | X509_FLAG_NO_AUX) == 1)
279 {
280 long len = BIO_get_mem_data(bp, &cp);
281
282 /* Strip leading " Signature Algorithm: " and trailing newline */
283 while (*cp && *cp != ':') { cp++; len--; }
284 do { cp++; len--; } while (*cp && *cp == ' ');
285 if (cp[len-1] == '\n') len--;
286
287 cp = string_copyn(cp, len);
288 }
289BIO_free(bp);
290return cp;
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291}
292
293uschar *
9e4dddbd 294tls_cert_subject(void * cert, uschar * mod)
9d1c15ef 295{
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296uschar * cp = x509_name_copy(X509_get_subject_name((X509 *)cert));
297return mod ? tls_field_from_dn(cp, mod) : cp;
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298}
299
300uschar *
9e4dddbd 301tls_cert_version(void * cert, uschar * mod)
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302{
303return string_sprintf("%d", X509_get_version((X509 *)cert));
304}
305
306uschar *
307tls_cert_ext_by_oid(void * cert, uschar * oid, int idx)
308{
e3dd1d67 309int nid = OBJ_create(CS oid, "", "");
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310int nidx = X509_get_ext_by_NID((X509 *)cert, nid, idx);
311X509_EXTENSION * ex = X509_get_ext((X509 *)cert, nidx);
312ASN1_OCTET_STRING * adata = X509_EXTENSION_get_data(ex);
313BIO * bp = BIO_new(BIO_s_mem());
314long len;
315uschar * cp1;
316uschar * cp2;
317uschar * cp3;
318
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319if (!bp) return badalloc();
320
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321#ifdef EXIM_HAVE_ASN1_MACROS
322ASN1_STRING_print(bp, adata);
323#else
9d1c15ef 324M_ASN1_OCTET_STRING_print(bp, adata);
c8dfb21d 325#endif
9d1c15ef 326
c8dfb21d 327/* binary data, DER encoded */
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328/* just dump for now */
329len = BIO_get_mem_data(bp, &cp1);
330cp3 = cp2 = store_get(len*3+1);
331
332while(len)
333 {
e3dd1d67 334 sprintf(CS cp2, "%.2x ", *cp1++);
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335 cp2 += 3;
336 len--;
337 }
338cp2[-1] = '\0';
339
340return cp3;
341}
342
343uschar *
9e4dddbd 344tls_cert_subject_altname(void * cert, uschar * mod)
9d1c15ef 345{
9e4dddbd 346uschar * list = NULL;
4226691b 347int lsize = 0, llen = 0;
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348STACK_OF(GENERAL_NAME) * san = (STACK_OF(GENERAL_NAME) *)
349 X509_get_ext_d2i((X509 *)cert, NID_subject_alt_name, NULL, NULL);
b3ef41c9 350uschar osep = '\n';
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351uschar * tag = US"";
352uschar * ele;
353int match = -1;
e51c7be2 354int len;
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355
356if (!san) return NULL;
357
b3ef41c9 358while (mod && *mod)
9e4dddbd 359 {
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360 if (*mod == '>' && *++mod) osep = *mod++;
361 else if (Ustrncmp(mod,"dns",3)==0) { match = GEN_DNS; mod += 3; }
362 else if (Ustrncmp(mod,"uri",3)==0) { match = GEN_URI; mod += 3; }
363 else if (Ustrncmp(mod,"mail",4)==0) { match = GEN_EMAIL; mod += 4; }
364 else mod++;
9e4dddbd 365
b3ef41c9 366 if (*mod == ',') mod++;
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367 }
368
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369while (sk_GENERAL_NAME_num(san) > 0)
370 {
371 GENERAL_NAME * namePart = sk_GENERAL_NAME_pop(san);
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372 if (match != -1 && match != namePart->type)
373 continue;
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374 switch (namePart->type)
375 {
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376 case GEN_DNS:
377 tag = US"DNS";
378 ele = ASN1_STRING_data(namePart->d.dNSName);
e51c7be2 379 len = ASN1_STRING_length(namePart->d.dNSName);
9e4dddbd 380 break;
9d1c15ef 381 case GEN_URI:
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382 tag = US"URI";
383 ele = ASN1_STRING_data(namePart->d.uniformResourceIdentifier);
e51c7be2 384 len = ASN1_STRING_length(namePart->d.uniformResourceIdentifier);
9e4dddbd 385 break;
9d1c15ef 386 case GEN_EMAIL:
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387 tag = US"MAIL";
388 ele = ASN1_STRING_data(namePart->d.rfc822Name);
e51c7be2 389 len = ASN1_STRING_length(namePart->d.rfc822Name);
9e4dddbd 390 break;
9d1c15ef 391 default:
9e4dddbd 392 continue; /* ignore unrecognised types */
9d1c15ef 393 }
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394 if (ele[len]) /* not nul-terminated */
395 ele = string_copyn(ele, len);
396
9acf6b94 397 if (Ustrlen(ele) == len) /* ignore any with embedded nul */
4226691b 398 list = string_append_listele(list, &lsize, &llen, osep,
9e4dddbd 399 match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
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400 }
401
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402sk_GENERAL_NAME_free(san);
403return list;
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404}
405
406uschar *
9e4dddbd 407tls_cert_ocsp_uri(void * cert, uschar * mod)
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408{
409STACK_OF(ACCESS_DESCRIPTION) * ads = (STACK_OF(ACCESS_DESCRIPTION) *)
410 X509_get_ext_d2i((X509 *)cert, NID_info_access, NULL, NULL);
411int adsnum = sk_ACCESS_DESCRIPTION_num(ads);
412int i;
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413uschar sep = '\n';
414uschar * list = NULL;
4226691b 415int size = 0, len = 0;
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416
417if (mod)
418 if (*mod == '>' && *++mod) sep = *mod++;
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419
420for (i = 0; i < adsnum; i++)
421 {
422 ACCESS_DESCRIPTION * ad = sk_ACCESS_DESCRIPTION_value(ads, i);
423
424 if (ad && OBJ_obj2nid(ad->method) == NID_ad_OCSP)
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425 list = string_append_listele_n(list, &size, &len, sep,
426 ASN1_STRING_data(ad->location->d.ia5),
427 ASN1_STRING_length(ad->location->d.ia5));
9d1c15ef 428 }
00ba27c5 429sk_ACCESS_DESCRIPTION_free(ads);
9e4dddbd 430return list;
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431}
432
433uschar *
9e4dddbd 434tls_cert_crl_uri(void * cert, uschar * mod)
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435{
436STACK_OF(DIST_POINT) * dps = (STACK_OF(DIST_POINT) *)
437 X509_get_ext_d2i((X509 *)cert, NID_crl_distribution_points,
438 NULL, NULL);
439DIST_POINT * dp;
440int dpsnum = sk_DIST_POINT_num(dps);
441int i;
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442uschar sep = '\n';
443uschar * list = NULL;
4226691b 444int size = 0, len = 0;
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445
446if (mod)
447 if (*mod == '>' && *++mod) sep = *mod++;
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448
449if (dps) for (i = 0; i < dpsnum; i++)
450 if ((dp = sk_DIST_POINT_value(dps, i)))
451 {
452 STACK_OF(GENERAL_NAME) * names = dp->distpoint->name.fullname;
453 GENERAL_NAME * np;
454 int nnum = sk_GENERAL_NAME_num(names);
455 int j;
456
457 for (j = 0; j < nnum; j++)
458 if ( (np = sk_GENERAL_NAME_value(names, j))
459 && np->type == GEN_URI
460 )
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461 list = string_append_listele_n(list, &size, &len, sep,
462 ASN1_STRING_data(np->d.uniformResourceIdentifier),
463 ASN1_STRING_length(np->d.uniformResourceIdentifier));
9d1c15ef 464 }
00ba27c5 465sk_DIST_POINT_free(dps);
9e4dddbd 466return list;
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467}
468
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469
470
471/*****************************************************
472* Certificate operator routines
473*****************************************************/
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474uschar *
475tls_cert_der_b64(void * cert)
476{
477BIO * bp = BIO_new(BIO_s_mem());
478uschar * cp = NULL;
479
480if (!i2d_X509_bio(bp, (X509 *)cert))
481 log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
482 ERR_error_string(ERR_get_error(), NULL));
483else
484 {
485 long len = BIO_get_mem_data(bp, &cp);
486 cp = b64encode(cp, (int)len);
487 }
488
489BIO_free(bp);
490return cp;
491}
492
493
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494static uschar *
495fingerprint(X509 * cert, const EVP_MD * fdig)
496{
497int j;
498unsigned int n;
499uschar md[EVP_MAX_MD_SIZE];
500uschar * cp;
501
502if (!X509_digest(cert,fdig,md,&n))
503 {
504 expand_string_message = US"tls_cert_fprt: out of mem\n";
505 return NULL;
506 }
507cp = store_get(n*2+1);
e3dd1d67 508for (j = 0; j < (int)n; j++) sprintf(CS cp+2*j, "%02X", md[j]);
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509return(cp);
510}
511
94431adb 512uschar *
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513tls_cert_fprt_md5(void * cert)
514{
515return fingerprint((X509 *)cert, EVP_md5());
516}
517
94431adb 518uschar *
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519tls_cert_fprt_sha1(void * cert)
520{
521return fingerprint((X509 *)cert, EVP_sha1());
522}
523
94431adb 524uschar *
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525tls_cert_fprt_sha256(void * cert)
526{
527return fingerprint((X509 *)cert, EVP_sha256());
528}
529
6a8a60e0 530
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531/* vi: aw ai sw=2
532*/
533/* End of tlscert-openssl.c */