constification
[exim.git] / src / src / tlscert-openssl.c
CommitLineData
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
f9ba5e22 5/* Copyright (c) Jeremy Harris 2014 - 2018 */
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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#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
25# define ASN1_STRING_get0_data ASN1_STRING_data
26#endif
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27
28/*****************************************************
29* Export/import a certificate, binary/printable
30*****************************************************/
31int
32tls_export_cert(uschar * buf, size_t buflen, void * cert)
33{
34BIO * bp = BIO_new(BIO_s_mem());
35int fail;
36
37if ((fail = PEM_write_bio_X509(bp, (X509 *)cert) ? 0 : 1))
38 log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
39 ERR_error_string(ERR_get_error(), NULL));
40else
41 {
42 char * cp = CS buf;
43 int n;
44 buflen -= 2;
45 for(;;)
46 {
47 if ((n = BIO_gets(bp, cp, (int)buflen)) <= 0) break;
48 cp += n+1;
49 buflen -= n+1;
50 cp[-2] = '\\'; cp[-1] = 'n'; /* newline->"\n" */
51 } /* compat with string_printing() */
52 *cp = '\0';
53 }
54
55BIO_free(bp);
56return fail;
57}
58
59int
60tls_import_cert(const uschar * buf, void ** cert)
61{
62void * reset_point = store_get(0);
63const uschar * cp = string_unprinting(US buf);
64BIO * bp;
152e7604 65X509 * x = *(X509 **)cert;
c03fae8a 66int fail = 0;
9d1c15ef 67
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68if (x) X509_free(x);
69
9d1c15ef 70bp = BIO_new_mem_buf(US cp, -1);
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71if (!(x = PEM_read_bio_X509(bp, NULL, 0, NULL)))
72 {
73 log_write(0, LOG_MAIN, "TLS error in certificate import: %s",
74 ERR_error_string(ERR_get_error(), NULL));
9d1c15ef 75 fail = 1;
c03fae8a 76 }
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77else
78 *cert = (void *)x;
79BIO_free(bp);
80store_reset(reset_point);
81return fail;
82}
83
84void
790fbb71 85tls_free_cert(void ** cert)
9d1c15ef 86{
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87X509 * x = *(X509 **)cert;
88if (x)
89 {
90 X509_free(x);
91 *cert = NULL;
92 }
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93}
94
c03fae8a 95
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96/*****************************************************
97* Certificate field extraction routines
98*****************************************************/
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99
100/* First, some internal service functions */
101
102static uschar *
103badalloc(void)
104{
105expand_string_message = US"allocation failure";
106return NULL;
107}
108
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109static uschar *
110bio_string_copy(BIO * bp, int len)
111{
e3dd1d67 112uschar * cp = US"";
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113len = len > 0 ? (int) BIO_get_mem_data(bp, &cp) : 0;
114cp = string_copyn(cp, len);
115BIO_free(bp);
116return cp;
117}
118
119static uschar *
e9477a08 120asn1_time_copy(const ASN1_TIME * asntime, uschar * mod)
9d1c15ef 121{
e9477a08 122uschar * s = NULL;
9d1c15ef 123BIO * bp = BIO_new(BIO_s_mem());
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124int len;
125
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126if (!bp)
127 return badalloc();
128len = ASN1_TIME_print(bp, asntime);
d4ff61d1 129len = len > 0 ? (int) BIO_get_mem_data(bp, CSS &s) : 0;
c03fae8a 130
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131if (mod && Ustrcmp(mod, "raw") == 0) /* native ASN */
132 s = string_copyn(s, len);
133else
134 {
135 struct tm tm;
136 struct tm * tm_p = &tm;
755762fd 137 BOOL mod_tz = TRUE;
45500060 138 uschar * tz = to_tz(US"GMT0"); /* need to call strptime with baseline TZ */
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139
140 /* Parse OpenSSL ASN1_TIME_print output. A shame there seems to
141 be no other interface for the times.
142 */
143
144 /*XXX %Z might be glibc-specific? Solaris has it, at least*/
145 /*XXX should we switch to POSIX locale for this? */
146 tm.tm_isdst = 0;
d4ff61d1 147 if (!len || !strptime(CCS s, "%b %e %T %Y %Z", &tm))
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148 expand_string_message = US"failed time conversion";
149
150 else
151 {
152 time_t t = mktime(&tm); /* make the tm self-consistent */
153
154 if (mod && Ustrcmp(mod, "int") == 0) /* seconds since epoch */
bb07bcd3 155 s = string_sprintf(TIME_T_FMT, t);
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156
157 else
158 {
8768d548 159 if (!f.timestamps_utc) /* decoded string in local TZ */
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160 { /* shift to local TZ */
161 restore_tz(tz);
162 mod_tz = FALSE;
163 tm_p = localtime(&t);
164 }
165 /* "utc" is default, and rfc5280 says cert times should be Zulu */
166
167 /* convert to string in our format */
168 len = 32;
169 s = store_get(len);
170 strftime(CS s, (size_t)len, "%b %e %T %Y %z", tm_p);
171 }
172 }
173
755762fd 174 if (mod_tz)
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175 restore_tz(tz);
176 }
177BIO_free(bp);
178return s;
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179}
180
181static uschar *
182x509_name_copy(X509_NAME * name)
183{
184BIO * bp = BIO_new(BIO_s_mem());
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185int len_good;
186
187if (!bp) return badalloc();
188
189len_good =
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190 X509_NAME_print_ex(bp, name, 0, XN_FLAG_RFC2253) >= 0
191 ? 1 : 0;
192return bio_string_copy(bp, len_good);
193}
194
195/**/
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196/* Now the extractors, called from expand.c
197Arguments:
198 cert The certificate
199 mod Optional modifiers for the operator
200
201Return:
202 Allocated string with extracted value
203*/
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204
205uschar *
9e4dddbd 206tls_cert_issuer(void * cert, uschar * mod)
9d1c15ef 207{
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208uschar * cp = x509_name_copy(X509_get_issuer_name((X509 *)cert));
209return mod ? tls_field_from_dn(cp, mod) : cp;
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210}
211
212uschar *
9e4dddbd 213tls_cert_not_before(void * cert, uschar * mod)
9d1c15ef 214{
25ba2544 215return asn1_time_copy(X509_get_notBefore((X509 *)cert), mod);
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216}
217
218uschar *
9e4dddbd 219tls_cert_not_after(void * cert, uschar * mod)
9d1c15ef 220{
25ba2544 221return asn1_time_copy(X509_get_notAfter((X509 *)cert), mod);
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222}
223
224uschar *
9e4dddbd 225tls_cert_serial_number(void * cert, uschar * mod)
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226{
227uschar txt[256];
228BIO * bp = BIO_new(BIO_s_mem());
c03fae8a 229int len;
9d1c15ef 230
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231if (!bp) return badalloc();
232
233len = i2a_ASN1_INTEGER(bp, X509_get_serialNumber((X509 *)cert));
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234if (len < sizeof(txt))
235 BIO_read(bp, txt, len);
236else
237 len = 0;
238BIO_free(bp);
239return string_copynlc(txt, len); /* lowercase */
240}
241
242uschar *
9e4dddbd 243tls_cert_signature(void * cert, uschar * mod)
9d1c15ef 244{
9d1c15ef 245uschar * cp = NULL;
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246BIO * bp = BIO_new(BIO_s_mem());
247
248if (!bp) return badalloc();
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249
250if (X509_print_ex(bp, (X509 *)cert, 0,
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251 X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL |
252 X509_FLAG_NO_SIGNAME | X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY |
253 X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS |
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254 /* X509_FLAG_NO_SIGDUMP is the missing one */
255 X509_FLAG_NO_AUX) == 1)
256 {
257 long len = BIO_get_mem_data(bp, &cp);
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258
259 /* Strip leading "Signature Algorithm" line */
260 while (*cp && *cp != '\n') { cp++; len--; }
261
262 cp = string_copyn(cp+1, len-1);
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263 }
264BIO_free(bp);
265return cp;
266}
267
268uschar *
9e4dddbd 269tls_cert_signature_algorithm(void * cert, uschar * mod)
9d1c15ef 270{
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271uschar * cp = NULL;
272BIO * bp = BIO_new(BIO_s_mem());
273
274if (!bp) return badalloc();
275
276if (X509_print_ex(bp, (X509 *)cert, 0,
94431adb 277 X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL |
315e209a 278 /* X509_FLAG_NO_SIGNAME is the missing one */
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279 X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY |
280 X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS |
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281 X509_FLAG_NO_SIGDUMP | X509_FLAG_NO_AUX) == 1)
282 {
283 long len = BIO_get_mem_data(bp, &cp);
284
285 /* Strip leading " Signature Algorithm: " and trailing newline */
286 while (*cp && *cp != ':') { cp++; len--; }
287 do { cp++; len--; } while (*cp && *cp == ' ');
288 if (cp[len-1] == '\n') len--;
289
290 cp = string_copyn(cp, len);
291 }
292BIO_free(bp);
293return cp;
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294}
295
296uschar *
9e4dddbd 297tls_cert_subject(void * cert, uschar * mod)
9d1c15ef 298{
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299uschar * cp = x509_name_copy(X509_get_subject_name((X509 *)cert));
300return mod ? tls_field_from_dn(cp, mod) : cp;
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301}
302
303uschar *
9e4dddbd 304tls_cert_version(void * cert, uschar * mod)
9d1c15ef 305{
bb07bcd3 306return string_sprintf("%ld", X509_get_version((X509 *)cert));
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307}
308
309uschar *
310tls_cert_ext_by_oid(void * cert, uschar * oid, int idx)
311{
e3dd1d67 312int nid = OBJ_create(CS oid, "", "");
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313int nidx = X509_get_ext_by_NID((X509 *)cert, nid, idx);
314X509_EXTENSION * ex = X509_get_ext((X509 *)cert, nidx);
315ASN1_OCTET_STRING * adata = X509_EXTENSION_get_data(ex);
316BIO * bp = BIO_new(BIO_s_mem());
317long len;
318uschar * cp1;
319uschar * cp2;
320uschar * cp3;
321
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322if (!bp) return badalloc();
323
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324#ifdef EXIM_HAVE_ASN1_MACROS
325ASN1_STRING_print(bp, adata);
326#else
9d1c15ef 327M_ASN1_OCTET_STRING_print(bp, adata);
c8dfb21d 328#endif
9d1c15ef 329
c8dfb21d 330/* binary data, DER encoded */
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331/* just dump for now */
332len = BIO_get_mem_data(bp, &cp1);
333cp3 = cp2 = store_get(len*3+1);
334
335while(len)
336 {
5976eb99 337 cp2 += sprintf(CS cp2, "%.2x ", *cp1++);
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338 len--;
339 }
340cp2[-1] = '\0';
341
342return cp3;
343}
344
345uschar *
9e4dddbd 346tls_cert_subject_altname(void * cert, uschar * mod)
9d1c15ef 347{
acec9514 348gstring * list = NULL;
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349STACK_OF(GENERAL_NAME) * san = (STACK_OF(GENERAL_NAME) *)
350 X509_get_ext_d2i((X509 *)cert, NID_subject_alt_name, NULL, NULL);
b3ef41c9 351uschar osep = '\n';
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352uschar * tag = US"";
353uschar * ele;
354int match = -1;
e51c7be2 355int len;
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356
357if (!san) return NULL;
358
b3ef41c9 359while (mod && *mod)
9e4dddbd 360 {
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361 if (*mod == '>' && *++mod) osep = *mod++;
362 else if (Ustrncmp(mod,"dns",3)==0) { match = GEN_DNS; mod += 3; }
363 else if (Ustrncmp(mod,"uri",3)==0) { match = GEN_URI; mod += 3; }
364 else if (Ustrncmp(mod,"mail",4)==0) { match = GEN_EMAIL; mod += 4; }
365 else mod++;
9e4dddbd 366
b3ef41c9 367 if (*mod == ',') mod++;
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368 }
369
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370while (sk_GENERAL_NAME_num(san) > 0)
371 {
372 GENERAL_NAME * namePart = sk_GENERAL_NAME_pop(san);
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373 if (match != -1 && match != namePart->type)
374 continue;
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375 switch (namePart->type)
376 {
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377 case GEN_DNS:
378 tag = US"DNS";
3ae79556 379 ele = US ASN1_STRING_get0_data(namePart->d.dNSName);
e51c7be2 380 len = ASN1_STRING_length(namePart->d.dNSName);
9e4dddbd 381 break;
9d1c15ef 382 case GEN_URI:
9e4dddbd 383 tag = US"URI";
3ae79556 384 ele = US ASN1_STRING_get0_data(namePart->d.uniformResourceIdentifier);
e51c7be2 385 len = ASN1_STRING_length(namePart->d.uniformResourceIdentifier);
9e4dddbd 386 break;
9d1c15ef 387 case GEN_EMAIL:
9e4dddbd 388 tag = US"MAIL";
3ae79556 389 ele = US ASN1_STRING_get0_data(namePart->d.rfc822Name);
e51c7be2 390 len = ASN1_STRING_length(namePart->d.rfc822Name);
9e4dddbd 391 break;
9d1c15ef 392 default:
9e4dddbd 393 continue; /* ignore unrecognised types */
9d1c15ef 394 }
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395 if (ele[len]) /* not nul-terminated */
396 ele = string_copyn(ele, len);
397
9acf6b94 398 if (Ustrlen(ele) == len) /* ignore any with embedded nul */
acec9514 399 list = string_append_listele(list, osep,
9e4dddbd 400 match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
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401 }
402
9e4dddbd 403sk_GENERAL_NAME_free(san);
acec9514 404return string_from_gstring(list);
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405}
406
407uschar *
9e4dddbd 408tls_cert_ocsp_uri(void * cert, uschar * mod)
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409{
410STACK_OF(ACCESS_DESCRIPTION) * ads = (STACK_OF(ACCESS_DESCRIPTION) *)
411 X509_get_ext_d2i((X509 *)cert, NID_info_access, NULL, NULL);
412int adsnum = sk_ACCESS_DESCRIPTION_num(ads);
9e4dddbd 413uschar sep = '\n';
acec9514 414gstring * list = NULL;
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415
416if (mod)
417 if (*mod == '>' && *++mod) sep = *mod++;
9d1c15ef 418
d7978c0f 419for (int i = 0; i < adsnum; i++)
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420 {
421 ACCESS_DESCRIPTION * ad = sk_ACCESS_DESCRIPTION_value(ads, i);
422
423 if (ad && OBJ_obj2nid(ad->method) == NID_ad_OCSP)
acec9514 424 list = string_append_listele_n(list, sep,
3ae79556 425 US ASN1_STRING_get0_data(ad->location->d.ia5),
4226691b 426 ASN1_STRING_length(ad->location->d.ia5));
9d1c15ef 427 }
00ba27c5 428sk_ACCESS_DESCRIPTION_free(ads);
acec9514 429return string_from_gstring(list);
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430}
431
432uschar *
9e4dddbd 433tls_cert_crl_uri(void * cert, uschar * mod)
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434{
435STACK_OF(DIST_POINT) * dps = (STACK_OF(DIST_POINT) *)
436 X509_get_ext_d2i((X509 *)cert, NID_crl_distribution_points,
437 NULL, NULL);
438DIST_POINT * dp;
9e4dddbd 439uschar sep = '\n';
acec9514 440gstring * list = NULL;
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441
442if (mod)
443 if (*mod == '>' && *++mod) sep = *mod++;
9d1c15ef 444
d7978c0f 445if (dps) for (int i = 0, dpsnum = sk_DIST_POINT_num(dps); i < dpsnum; i++)
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446 if ((dp = sk_DIST_POINT_value(dps, i)))
447 {
448 STACK_OF(GENERAL_NAME) * names = dp->distpoint->name.fullname;
449 GENERAL_NAME * np;
9d1c15ef 450
d7978c0f 451 for (int j = 0, nnum = sk_GENERAL_NAME_num(names); j < nnum; j++)
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452 if ( (np = sk_GENERAL_NAME_value(names, j))
453 && np->type == GEN_URI
454 )
acec9514 455 list = string_append_listele_n(list, sep,
3ae79556 456 US ASN1_STRING_get0_data(np->d.uniformResourceIdentifier),
4226691b 457 ASN1_STRING_length(np->d.uniformResourceIdentifier));
9d1c15ef 458 }
00ba27c5 459sk_DIST_POINT_free(dps);
acec9514 460return string_from_gstring(list);
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461}
462
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463
464
465/*****************************************************
466* Certificate operator routines
467*****************************************************/
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468uschar *
469tls_cert_der_b64(void * cert)
470{
471BIO * bp = BIO_new(BIO_s_mem());
472uschar * cp = NULL;
473
474if (!i2d_X509_bio(bp, (X509 *)cert))
475 log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
476 ERR_error_string(ERR_get_error(), NULL));
477else
478 {
479 long len = BIO_get_mem_data(bp, &cp);
1f20760b 480 cp = b64encode(CUS cp, (int)len);
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481 }
482
483BIO_free(bp);
484return cp;
485}
486
487
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488static uschar *
489fingerprint(X509 * cert, const EVP_MD * fdig)
490{
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491unsigned int n;
492uschar md[EVP_MAX_MD_SIZE];
493uschar * cp;
494
495if (!X509_digest(cert,fdig,md,&n))
496 {
497 expand_string_message = US"tls_cert_fprt: out of mem\n";
498 return NULL;
499 }
500cp = store_get(n*2+1);
d7978c0f 501for (int j = 0; j < (int)n; j++) sprintf(CS cp+2*j, "%02X", md[j]);
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502return(cp);
503}
504
94431adb 505uschar *
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506tls_cert_fprt_md5(void * cert)
507{
508return fingerprint((X509 *)cert, EVP_md5());
509}
510
94431adb 511uschar *
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512tls_cert_fprt_sha1(void * cert)
513{
514return fingerprint((X509 *)cert, EVP_sha1());
515}
516
94431adb 517uschar *
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518tls_cert_fprt_sha256(void * cert)
519{
520return fingerprint((X509 *)cert, EVP_sha256());
521}
522
6a8a60e0 523
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524/* vi: aw ai sw=2
525*/
526/* End of tlscert-openssl.c */