1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) Jeremy Harris 2014 - 2018 */
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.
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>
21 /*****************************************************
22 * Export/import a certificate, binary/printable
23 *****************************************************/
25 tls_export_cert(uschar * buf, size_t buflen, void * cert)
28 void * reset_point = store_get(0);
32 if ((fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
33 GNUTLS_X509_FMT_PEM, buf, &sz)))
35 log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
36 gnutls_strerror(fail));
39 if ((cp = string_printing(buf)) != buf)
41 Ustrncpy(buf, cp, buflen);
45 store_reset(reset_point);
50 tls_import_cert(const uschar * buf, void ** cert)
52 void * reset_point = store_get(0);
54 gnutls_x509_crt_t crt = *(gnutls_x509_crt_t *)cert;
58 gnutls_x509_crt_deinit(crt);
62 gnutls_x509_crt_init(&crt);
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)))
68 log_write(0, LOG_MAIN, "TLS error in certificate import: %s",
69 gnutls_strerror(fail));
75 store_reset(reset_point);
80 tls_free_cert(void ** cert)
82 gnutls_x509_crt_t crt = *(gnutls_x509_crt_t *)cert;
85 gnutls_x509_crt_deinit(crt);
86 gnutls_global_deinit();
91 /*****************************************************
92 * Certificate field extraction routines
93 *****************************************************/
95 /* First, some internal service functions */
98 g_err(const char * tag, const char * from, int gnutls_err)
100 expand_string_message = string_sprintf("%s: %s fail: %s\n",
101 from, tag, gnutls_strerror(gnutls_err));
107 time_copy(time_t t, uschar * mod)
112 if (mod && Ustrcmp(mod, "int") == 0)
113 return string_sprintf("%u", (unsigned)t);
118 uschar * tz = to_tz(US"GMT0");
119 len = strftime(CS cp, len, "%b %e %T %Y %Z", gmtime(&t));
123 len = strftime(CS cp, len, "%b %e %T %Y %Z", localtime(&t));
124 return len > 0 ? cp : NULL;
129 /* Now the extractors, called from expand.c
132 mod Optional modifiers for the operator
135 Allocated string with extracted value
139 tls_cert_issuer(void * cert, uschar * mod)
145 if ((ret = gnutls_x509_crt_get_issuer_dn(cert, CS cp, &siz))
146 != GNUTLS_E_SHORT_MEMORY_BUFFER)
147 return g_err("gi0", __FUNCTION__, ret);
150 if ((ret = gnutls_x509_crt_get_issuer_dn(cert, CS cp, &siz)) < 0)
151 return g_err("gi1", __FUNCTION__, ret);
153 return mod ? tls_field_from_dn(cp, mod) : cp;
157 tls_cert_not_after(void * cert, uschar * mod)
160 gnutls_x509_crt_get_expiration_time((gnutls_x509_crt_t)cert),
165 tls_cert_not_before(void * cert, uschar * mod)
168 gnutls_x509_crt_get_activation_time((gnutls_x509_crt_t)cert),
173 tls_cert_serial_number(void * cert, uschar * mod)
175 uschar bin[50], txt[150];
176 size_t sz = sizeof(bin);
181 if ((ret = gnutls_x509_crt_get_serial((gnutls_x509_crt_t)cert,
183 return g_err("gs0", __FUNCTION__, ret);
185 for(dp = txt, sp = bin; sz; sz--)
186 dp += sprintf(CS dp, "%.2x", *sp++);
187 for(sp = txt; sp[0]=='0' && sp[1]; ) sp++; /* leading zeroes */
188 return string_copy(sp);
192 tls_cert_signature(void * cert, uschar * mod)
200 if ((ret = gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len))
201 != GNUTLS_E_SHORT_MEMORY_BUFFER)
202 return g_err("gs0", __FUNCTION__, ret);
204 cp1 = store_get(len*4+1);
205 if (gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len) != 0)
206 return g_err("gs1", __FUNCTION__, ret);
208 for(cp3 = cp2 = cp1+len; cp1 < cp2; cp1++)
209 cp3 += sprintf(CS cp3, "%.2x ", *cp1);
216 tls_cert_signature_algorithm(void * cert, uschar * mod)
218 gnutls_sign_algorithm_t algo =
219 gnutls_x509_crt_get_signature_algorithm((gnutls_x509_crt_t)cert);
220 return algo < 0 ? NULL : string_copy(US gnutls_sign_get_name(algo));
224 tls_cert_subject(void * cert, uschar * mod)
230 if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz))
231 != GNUTLS_E_SHORT_MEMORY_BUFFER)
232 return g_err("gs0", __FUNCTION__, ret);
235 if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz)) < 0)
236 return g_err("gs1", __FUNCTION__, ret);
238 return mod ? tls_field_from_dn(cp, mod) : cp;
242 tls_cert_version(void * cert, uschar * mod)
244 return string_sprintf("%d", gnutls_x509_crt_get_version(cert));
248 tls_cert_ext_by_oid(void * cert, uschar * oid, int idx)
257 ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,
258 oid, idx, CS cp1, &siz, &crit);
259 if (ret != GNUTLS_E_SHORT_MEMORY_BUFFER)
260 return g_err("ge0", __FUNCTION__, ret);
262 cp1 = store_get(siz*4 + 1);
264 ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,
265 oid, idx, CS cp1, &siz, &crit);
267 return g_err("ge1", __FUNCTION__, ret);
269 /* binary data, DER encoded */
271 /* just dump for now */
272 for(cp3 = cp2 = cp1+siz; cp1 < cp2; cp1++)
273 cp3 += sprintf(CS cp3, "%.2x ", *cp1);
280 tls_cert_subject_altname(void * cert, uschar * mod)
282 gstring * list = NULL;
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; }
303 for(index = 0;; index++)
306 switch(ret = gnutls_x509_crt_get_subject_alt_name(
307 (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL))
309 case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:
310 return string_from_gstring(list); /* no more elements; normal exit */
312 case GNUTLS_E_SHORT_MEMORY_BUFFER:
316 return g_err("gs0", __FUNCTION__, ret);
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);
325 if ( match != -1 && match != ret /* wrong type of SAN */
326 || Ustrlen(ele) != siz) /* contains a NUL */
330 case GNUTLS_SAN_DNSNAME: tag = US"DNS"; break;
331 case GNUTLS_SAN_URI: tag = US"URI"; break;
332 case GNUTLS_SAN_RFC822NAME: tag = US"MAIL"; break;
333 default: continue; /* ignore unrecognised types */
335 list = string_append_listele(list, sep,
336 match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
342 tls_cert_ocsp_uri(void * cert, uschar * mod)
344 #if GNUTLS_VERSION_NUMBER >= 0x030000
349 gstring * list = NULL;
352 if (*mod == '>' && *++mod) sep = *mod++;
354 for(index = 0;; index++)
356 ret = gnutls_x509_crt_get_authority_info_access((gnutls_x509_crt_t)cert,
357 index, GNUTLS_IA_OCSP_URI, &uri, NULL);
359 if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
360 return string_from_gstring(list);
362 return g_err("gai", __FUNCTION__, ret);
364 list = string_append_listele_n(list, sep, uri.data, uri.size);
370 expand_string_message =
371 string_sprintf("%s: OCSP support with GnuTLS requires version 3.0.0\n",
379 tls_cert_crl_uri(void * cert, uschar * mod)
385 gstring * list = NULL;
389 if (*mod == '>' && *++mod) sep = *mod++;
391 for(index = 0;; index++)
394 switch(ret = gnutls_x509_crt_get_crl_dist_points(
395 (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL, NULL))
397 case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:
398 return string_from_gstring(list);
399 case GNUTLS_E_SHORT_MEMORY_BUFFER:
402 return g_err("gc0", __FUNCTION__, ret);
405 ele = store_get(siz);
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);
410 list = string_append_listele_n(list, sep, ele, siz);
416 /*****************************************************
417 * Certificate operator routines
418 *****************************************************/
420 tls_cert_der_b64(void * cert)
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))
433 log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
434 gnutls_strerror(fail));
437 return b64encode(cp, (int)len);
442 fingerprint(gnutls_x509_crt_t cert, gnutls_digest_algorithm_t algo)
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);
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);
458 for (cp3 = cp2 = cp+siz; cp < cp2; cp++)
459 cp3 += sprintf(CS cp3, "%02X", *cp);
465 tls_cert_fprt_md5(void * cert)
467 return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_MD5);
471 tls_cert_fprt_sha1(void * cert)
473 return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA1);
477 tls_cert_fprt_sha256(void * cert)
479 return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA256);
485 /* End of tlscert-gnu.c */