[exim.git] / src / src / tlscert-gnu.c

/*************************************************
*     Exim - an Internet mail transport agent    *
*************************************************/

/* Copyright (c) Jeremy Harris 2014 - 2018 */

/* This file provides TLS/SSL support for Exim using the GnuTLS library,
one of the available supported implementations.  This file is #included into
tls.c when USE_GNUTLS has been set.
*/

#include <gnutls/gnutls.h>
/* needed for cert checks in verification and DN extraction: */
#include <gnutls/x509.h>
/* needed to disable PKCS11 autoload unless requested */
#if GNUTLS_VERSION_NUMBER >= 0x020c00
# include <gnutls/pkcs11.h>
#endif


/*****************************************************
*  Export/import a certificate, binary/printable
*****************************************************/
int
tls_export_cert(uschar * buf, size_t buflen, void * cert)
{
size_t sz = buflen;
void * reset_point = store_get(0);
int fail;
const uschar * cp;

if ((fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
    GNUTLS_X509_FMT_PEM, buf, &sz)))
  {
  log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
    gnutls_strerror(fail));
  return 1;
  }
if ((cp = string_printing(buf)) != buf)
  {
  Ustrncpy(buf, cp, buflen);
  if (buf[buflen-1])
    fail = 1;
  }
store_reset(reset_point);
return fail;
}

int
tls_import_cert(const uschar * buf, void ** cert)
{
void * reset_point = store_get(0);
gnutls_datum_t datum;
gnutls_x509_crt_t crt = *(gnutls_x509_crt_t *)cert;
int fail = 0;

if (crt)
  gnutls_x509_crt_deinit(crt);
else
  gnutls_global_init();

gnutls_x509_crt_init(&crt);

datum.data = string_unprinting(US buf);
datum.size = Ustrlen(datum.data);
if ((fail = gnutls_x509_crt_import(crt, &datum, GNUTLS_X509_FMT_PEM)))
  {
  log_write(0, LOG_MAIN, "TLS error in certificate import: %s",
    gnutls_strerror(fail));
  fail = 1;
  }
else
  *cert = (void *)crt;

store_reset(reset_point);
return fail;
}

void
tls_free_cert(void ** cert)
{
gnutls_x509_crt_t crt = *(gnutls_x509_crt_t *)cert;
if (crt)
  {
  gnutls_x509_crt_deinit(crt);
  gnutls_global_deinit();
  *cert = NULL;
  }
}

/*****************************************************
*  Certificate field extraction routines
*****************************************************/

/* First, some internal service functions */

static uschar *
g_err(const char * tag, const char * from, int gnutls_err)
{
expand_string_message = string_sprintf("%s: %s fail: %s\n",
  from, tag, gnutls_strerror(gnutls_err));
return NULL;
}


static uschar *
time_copy(time_t t, uschar * mod)
{
uschar * cp;
size_t len = 32;

if (mod && Ustrcmp(mod, "int") == 0)
  return string_sprintf("%u", (unsigned)t);

cp = store_get(len);
if (f.timestamps_utc)
  {
  uschar * tz = to_tz(US"GMT0");
  len = strftime(CS cp, len, "%b %e %T %Y %Z", gmtime(&t));
  restore_tz(tz);
  }
else
  len = strftime(CS cp, len, "%b %e %T %Y %Z", localtime(&t));
return len > 0 ? cp : NULL;
}


/**/
/* Now the extractors, called from expand.c
Arguments:
  cert		The certificate
  mod		Optional modifiers for the operator

Return:
  Allocated string with extracted value
*/

uschar *
tls_cert_issuer(void * cert, uschar * mod)
{
uschar * cp = NULL;
int ret;
size_t siz = 0;

if ((ret = gnutls_x509_crt_get_issuer_dn(cert, CS cp, &siz))
    != GNUTLS_E_SHORT_MEMORY_BUFFER)
  return g_err("gi0", __FUNCTION__, ret);

cp = store_get(siz);
if ((ret = gnutls_x509_crt_get_issuer_dn(cert, CS cp, &siz)) < 0)
  return g_err("gi1", __FUNCTION__, ret);

return mod ? tls_field_from_dn(cp, mod) : cp;
}

uschar *
tls_cert_not_after(void * cert, uschar * mod)
{
return time_copy(
  gnutls_x509_crt_get_expiration_time((gnutls_x509_crt_t)cert),
  mod);
}

uschar *
tls_cert_not_before(void * cert, uschar * mod)
{
return time_copy(
  gnutls_x509_crt_get_activation_time((gnutls_x509_crt_t)cert),
  mod);
}

uschar *
tls_cert_serial_number(void * cert, uschar * mod)
{
uschar bin[50], txt[150];
uschar * sp = bin;
size_t sz = sizeof(bin);
int ret;

if ((ret = gnutls_x509_crt_get_serial((gnutls_x509_crt_t)cert,
    bin, &sz)))
  return g_err("gs0", __FUNCTION__, ret);

for(uschar * dp = txt; sz; sz--)
  dp += sprintf(CS dp, "%.2x", *sp++);
for(sp = txt; sp[0]=='0' && sp[1]; ) sp++;	/* leading zeroes */
return string_copy(sp);
}

uschar *
tls_cert_signature(void * cert, uschar * mod)
{
uschar * cp1 = NULL;
uschar * cp2;
uschar * cp3;
size_t len = 0;
int ret;

if ((ret = gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len))
    != GNUTLS_E_SHORT_MEMORY_BUFFER)
  return g_err("gs0", __FUNCTION__, ret);

cp1 = store_get(len*4+1);
if (gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len) != 0)
  return g_err("gs1", __FUNCTION__, ret);

for(cp3 = cp2 = cp1+len; cp1 < cp2; cp1++)
  cp3 += sprintf(CS cp3, "%.2x ", *cp1);
cp3[-1]= '\0';

return cp2;
}

uschar *
tls_cert_signature_algorithm(void * cert, uschar * mod)
{
gnutls_sign_algorithm_t algo =
  gnutls_x509_crt_get_signature_algorithm((gnutls_x509_crt_t)cert);
return algo < 0 ? NULL : string_copy(US gnutls_sign_get_name(algo));
}

uschar *
tls_cert_subject(void * cert, uschar * mod)
{
uschar * cp = NULL;
int ret;
size_t siz = 0;

if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz))
    != GNUTLS_E_SHORT_MEMORY_BUFFER)
  return g_err("gs0", __FUNCTION__, ret);

cp = store_get(siz);
if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz)) < 0)
  return g_err("gs1", __FUNCTION__, ret);

return mod ? tls_field_from_dn(cp, mod) : cp;
}

uschar *
tls_cert_version(void * cert, uschar * mod)
{
return string_sprintf("%d", gnutls_x509_crt_get_version(cert));
}

uschar *
tls_cert_ext_by_oid(void * cert, uschar * oid, int idx)
{
uschar * cp1 = NULL;
uschar * cp2;
uschar * cp3;
size_t siz = 0;
unsigned int crit;
int ret;

ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,
  CS oid, idx, CS cp1, &siz, &crit);
if (ret != GNUTLS_E_SHORT_MEMORY_BUFFER)
  return g_err("ge0", __FUNCTION__, ret);

cp1 = store_get(siz*4 + 1);

ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,
  CS oid, idx, CS cp1, &siz, &crit);
if (ret < 0)
  return g_err("ge1", __FUNCTION__, ret);

/* binary data, DER encoded */

/* just dump for now */
for(cp3 = cp2 = cp1+siz; cp1 < cp2; cp1++)
  cp3 += sprintf(CS cp3, "%.2x ", *cp1);
cp3[-1]= '\0';

return cp2;
}

uschar *
tls_cert_subject_altname(void * cert, uschar * mod)
{
gstring * list = NULL;
size_t siz;
int ret;
uschar sep = '\n';
uschar * tag = US"";
uschar * ele;
int match = -1;

while (mod)
  {
  if (*mod == '>' && *++mod) sep = *mod++;
  else if (Ustrcmp(mod, "dns")==0) { match = GNUTLS_SAN_DNSNAME; mod += 3; }
  else if (Ustrcmp(mod, "uri")==0) { match = GNUTLS_SAN_URI; mod += 3; }
  else if (Ustrcmp(mod, "mail")==0) { match = GNUTLS_SAN_RFC822NAME; mod += 4; }
  else continue;

  if (*mod++ != ',')
    break;
  }

for (int index = 0;; index++)
  {
  siz = 0;
  switch(ret = gnutls_x509_crt_get_subject_alt_name(
      (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL))
    {
    case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:
      return string_from_gstring(list);	/* no more elements; normal exit */

    case GNUTLS_E_SHORT_MEMORY_BUFFER:
      break;

    default:
      return g_err("gs0", __FUNCTION__, ret);
    }

  ele = store_get(siz+1);
  if ((ret = gnutls_x509_crt_get_subject_alt_name(
    (gnutls_x509_crt_t)cert, index, ele, &siz, NULL)) < 0)
    return g_err("gs1", __FUNCTION__, ret);
  ele[siz] = '\0';

  if (  match != -1 && match != ret	/* wrong type of SAN */
     || Ustrlen(ele) != siz)		/* contains a NUL */
    continue;
  switch (ret)
    {
    case GNUTLS_SAN_DNSNAME:    tag = US"DNS";  break;
    case GNUTLS_SAN_URI:        tag = US"URI";  break;
    case GNUTLS_SAN_RFC822NAME: tag = US"MAIL"; break;
    default: continue;        /* ignore unrecognised types */
    }
  list = string_append_listele(list, sep,
          match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
  }
/*NOTREACHED*/
}

uschar *
tls_cert_ocsp_uri(void * cert, uschar * mod)
{
#if GNUTLS_VERSION_NUMBER >= 0x030000
gnutls_datum_t uri;
int ret;
uschar sep = '\n';
gstring * list = NULL;

if (mod)
  if (*mod == '>' && *++mod) sep = *mod++;

for (int index = 0;; index++)
  {
  ret = gnutls_x509_crt_get_authority_info_access((gnutls_x509_crt_t)cert,
	  index, GNUTLS_IA_OCSP_URI, &uri, NULL);

  if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
    return string_from_gstring(list);
  if (ret < 0)
    return g_err("gai", __FUNCTION__, ret);

  list = string_append_listele_n(list, sep, uri.data, uri.size);
  }
/*NOTREACHED*/

#else

expand_string_message =
  string_sprintf("%s: OCSP support with GnuTLS requires version 3.0.0\n",
    __FUNCTION__);
return NULL;

#endif
}

uschar *
tls_cert_crl_uri(void * cert, uschar * mod)
{
int ret;
uschar sep = '\n';
gstring * list = NULL;
uschar * ele;

if (mod)
  if (*mod == '>' && *++mod) sep = *mod++;

for (int index = 0;; index++)
  {
  size_t siz = 0;
  switch(ret = gnutls_x509_crt_get_crl_dist_points(
    (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL, NULL))
    {
    case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:
      return string_from_gstring(list);
    case GNUTLS_E_SHORT_MEMORY_BUFFER:
      break;
    default:
      return g_err("gc0", __FUNCTION__, ret);
    }

  ele = store_get(siz);
  if ((ret = gnutls_x509_crt_get_crl_dist_points(
      (gnutls_x509_crt_t)cert, index, ele, &siz, NULL, NULL)) < 0)
    return g_err("gc1", __FUNCTION__, ret);

  list = string_append_listele_n(list, sep, ele, siz);
  }
/*NOTREACHED*/
}


/*****************************************************
*  Certificate operator routines
*****************************************************/
uschar *
tls_cert_der_b64(void * cert)
{
size_t len = 0;
uschar * cp = NULL;
int fail;

if (  (fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
	GNUTLS_X509_FMT_DER, cp, &len)) != GNUTLS_E_SHORT_MEMORY_BUFFER
   || !(cp = store_get((int)len))
   || (fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
        GNUTLS_X509_FMT_DER, cp, &len))
   )
  {
  log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
    gnutls_strerror(fail));
  return NULL;
  }
return b64encode(cp, (int)len);
}


static uschar *
fingerprint(gnutls_x509_crt_t cert, gnutls_digest_algorithm_t algo)
{
int ret;
size_t siz = 0;
uschar * cp;
uschar * cp2;

if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, NULL, &siz))
    != GNUTLS_E_SHORT_MEMORY_BUFFER)
  return g_err("gf0", __FUNCTION__, ret);

cp = store_get(siz*3+1);
if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, cp, &siz)) < 0)
  return g_err("gf1", __FUNCTION__, ret);

for (uschar * cp3 = cp2 = cp+siz; cp < cp2; cp++)
  cp3 += sprintf(CS cp3, "%02X", *cp);
return cp2;
}


uschar *
tls_cert_fprt_md5(void * cert)
{
return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_MD5);
}

uschar *
tls_cert_fprt_sha1(void * cert)
{
return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA1);
}

uschar *
tls_cert_fprt_sha256(void * cert)
{
return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA256);
}


/* vi: aw ai sw=2
*/
/* End of tlscert-gnu.c */
Commit	Line	Data
	1	/*************************************************
	2	* Exim - an Internet mail transport agent *
	3	*************************************************/
	4
	5	/* Copyright (c) Jeremy Harris 2014 - 2018 */
	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	const 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 = (gnutls_x509_crt_t )cert;
	55	int fail = 0;
	56
	57	if (crt)
	58	gnutls_x509_crt_deinit(crt);
	59	else
	60	gnutls_global_init();
	61
	62	gnutls_x509_crt_init(&crt);
	63
	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)))
	67	{
	68	log_write(0, LOG_MAIN, "TLS error in certificate import: %s",
	69	gnutls_strerror(fail));
	70	fail = 1;
	71	}
	72	else
	73	cert = (void )crt;
	74
	75	store_reset(reset_point);
	76	return fail;
	77	}
	78
	79	void
	80	tls_free_cert(void ** cert)
	81	{
	82	gnutls_x509_crt_t crt = (gnutls_x509_crt_t )cert;
	83	if (crt)
	84	{
	85	gnutls_x509_crt_deinit(crt);
	86	gnutls_global_deinit();
	87	*cert = NULL;
	88	}
	89	}
	90
	91	/*****************************************************
	92	* Certificate field extraction routines
	93	*****************************************************/
	94
	95	/* First, some internal service functions */
	96
	97	static uschar *
	98	g_err(const char * tag, const char * from, int gnutls_err)
	99	{
	100	expand_string_message = string_sprintf("%s: %s fail: %s\n",
	101	from, tag, gnutls_strerror(gnutls_err));
	102	return NULL;
	103	}
	104
	105
	106	static uschar *
	107	time_copy(time_t t, uschar * mod)
	108	{
	109	uschar * cp;
	110	size_t len = 32;
	111
	112	if (mod && Ustrcmp(mod, "int") == 0)
	113	return string_sprintf("%u", (unsigned)t);
	114
	115	cp = store_get(len);
	116	if (f.timestamps_utc)
	117	{
	118	uschar * tz = to_tz(US"GMT0");
	119	len = strftime(CS cp, len, "%b %e %T %Y %Z", gmtime(&t));
	120	restore_tz(tz);
	121	}
	122	else
	123	len = strftime(CS cp, len, "%b %e %T %Y %Z", localtime(&t));
	124	return len > 0 ? cp : NULL;
	125	}
	126
	127
	128	/**/
	129	/* Now the extractors, called from expand.c
	130	Arguments:
	131	cert The certificate
	132	mod Optional modifiers for the operator
	133
	134	Return:
	135	Allocated string with extracted value
	136	*/
	137
	138	uschar *
	139	tls_cert_issuer(void * cert, uschar * mod)
	140	{
	141	uschar * cp = NULL;
	142	int ret;
	143	size_t siz = 0;
	144
	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);
	148
	149	cp = store_get(siz);
	150	if ((ret = gnutls_x509_crt_get_issuer_dn(cert, CS cp, &siz)) < 0)
	151	return g_err("gi1", __FUNCTION__, ret);
	152
	153	return mod ? tls_field_from_dn(cp, mod) : cp;
	154	}
	155
	156	uschar *
	157	tls_cert_not_after(void * cert, uschar * mod)
	158	{
	159	return time_copy(
	160	gnutls_x509_crt_get_expiration_time((gnutls_x509_crt_t)cert),
	161	mod);
	162	}
	163
	164	uschar *
	165	tls_cert_not_before(void * cert, uschar * mod)
	166	{
	167	return time_copy(
	168	gnutls_x509_crt_get_activation_time((gnutls_x509_crt_t)cert),
	169	mod);
	170	}
	171
	172	uschar *
	173	tls_cert_serial_number(void * cert, uschar * mod)
	174	{
	175	uschar bin[50], txt[150];
	176	uschar * sp = bin;
	177	size_t sz = sizeof(bin);
	178	int ret;
	179
	180	if ((ret = gnutls_x509_crt_get_serial((gnutls_x509_crt_t)cert,
	181	bin, &sz)))
	182	return g_err("gs0", __FUNCTION__, ret);
	183
	184	for(uschar * dp = txt; sz; sz--)
	185	dp += sprintf(CS dp, "%.2x", *sp++);
	186	for(sp = txt; sp[0]=='0' && sp[1]; ) sp++; /* leading zeroes */
	187	return string_copy(sp);
	188	}
	189
	190	uschar *
	191	tls_cert_signature(void * cert, uschar * mod)
	192	{
	193	uschar * cp1 = NULL;
	194	uschar * cp2;
	195	uschar * cp3;
	196	size_t len = 0;
	197	int ret;
	198
	199	if ((ret = gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len))
	200	!= GNUTLS_E_SHORT_MEMORY_BUFFER)
	201	return g_err("gs0", __FUNCTION__, ret);
	202
	203	cp1 = store_get(len*4+1);
	204	if (gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len) != 0)
	205	return g_err("gs1", __FUNCTION__, ret);
	206
	207	for(cp3 = cp2 = cp1+len; cp1 < cp2; cp1++)
	208	cp3 += sprintf(CS cp3, "%.2x ", *cp1);
	209	cp3[-1]= '\0';
	210
	211	return cp2;
	212	}
	213
	214	uschar *
	215	tls_cert_signature_algorithm(void * cert, uschar * mod)
	216	{
	217	gnutls_sign_algorithm_t algo =
	218	gnutls_x509_crt_get_signature_algorithm((gnutls_x509_crt_t)cert);
	219	return algo < 0 ? NULL : string_copy(US gnutls_sign_get_name(algo));
	220	}
	221
	222	uschar *
	223	tls_cert_subject(void * cert, uschar * mod)
	224	{
	225	uschar * cp = NULL;
	226	int ret;
	227	size_t siz = 0;
	228
	229	if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz))
	230	!= GNUTLS_E_SHORT_MEMORY_BUFFER)
	231	return g_err("gs0", __FUNCTION__, ret);
	232
	233	cp = store_get(siz);
	234	if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz)) < 0)
	235	return g_err("gs1", __FUNCTION__, ret);
	236
	237	return mod ? tls_field_from_dn(cp, mod) : cp;
	238	}
	239
	240	uschar *
	241	tls_cert_version(void * cert, uschar * mod)
	242	{
	243	return string_sprintf("%d", gnutls_x509_crt_get_version(cert));
	244	}
	245
	246	uschar *
	247	tls_cert_ext_by_oid(void * cert, uschar * oid, int idx)
	248	{
	249	uschar * cp1 = NULL;
	250	uschar * cp2;
	251	uschar * cp3;
	252	size_t siz = 0;
	253	unsigned int crit;
	254	int ret;
	255
	256	ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,
	257	CS oid, idx, CS cp1, &siz, &crit);
	258	if (ret != GNUTLS_E_SHORT_MEMORY_BUFFER)
	259	return g_err("ge0", __FUNCTION__, ret);
	260
	261	cp1 = store_get(siz*4 + 1);
	262
	263	ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,
	264	CS oid, idx, CS cp1, &siz, &crit);
	265	if (ret < 0)
	266	return g_err("ge1", __FUNCTION__, ret);
	267
	268	/* binary data, DER encoded */
	269
	270	/* just dump for now */
	271	for(cp3 = cp2 = cp1+siz; cp1 < cp2; cp1++)
	272	cp3 += sprintf(CS cp3, "%.2x ", *cp1);
	273	cp3[-1]= '\0';
	274
	275	return cp2;
	276	}
	277
	278	uschar *
	279	tls_cert_subject_altname(void * cert, uschar * mod)
	280	{
	281	gstring * list = NULL;
	282	size_t siz;
	283	int ret;
	284	uschar sep = '\n';
	285	uschar * tag = US"";
	286	uschar * ele;
	287	int match = -1;
	288
	289	while (mod)
	290	{
	291	if (mod == '>' && ++mod) sep = *mod++;
	292	else if (Ustrcmp(mod, "dns")==0) { match = GNUTLS_SAN_DNSNAME; mod += 3; }
	293	else if (Ustrcmp(mod, "uri")==0) { match = GNUTLS_SAN_URI; mod += 3; }
	294	else if (Ustrcmp(mod, "mail")==0) { match = GNUTLS_SAN_RFC822NAME; mod += 4; }
	295	else continue;
	296
	297	if (*mod++ != ',')
	298	break;
	299	}
	300
	301	for (int index = 0;; index++)
	302	{
	303	siz = 0;
	304	switch(ret = gnutls_x509_crt_get_subject_alt_name(
	305	(gnutls_x509_crt_t)cert, index, NULL, &siz, NULL))
	306	{
	307	case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:
	308	return string_from_gstring(list); /* no more elements; normal exit */
	309
	310	case GNUTLS_E_SHORT_MEMORY_BUFFER:
	311	break;
	312
	313	default:
	314	return g_err("gs0", __FUNCTION__, ret);
	315	}
	316
	317	ele = store_get(siz+1);
	318	if ((ret = gnutls_x509_crt_get_subject_alt_name(
	319	(gnutls_x509_crt_t)cert, index, ele, &siz, NULL)) < 0)
	320	return g_err("gs1", __FUNCTION__, ret);
	321	ele[siz] = '\0';
	322
	323	if ( match != -1 && match != ret /* wrong type of SAN */
	324	\|\| Ustrlen(ele) != siz) /* contains a NUL */
	325	continue;
	326	switch (ret)
	327	{
	328	case GNUTLS_SAN_DNSNAME: tag = US"DNS"; break;
	329	case GNUTLS_SAN_URI: tag = US"URI"; break;
	330	case GNUTLS_SAN_RFC822NAME: tag = US"MAIL"; break;
	331	default: continue; /* ignore unrecognised types */
	332	}
	333	list = string_append_listele(list, sep,
	334	match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
	335	}
	336	/NOTREACHED/
	337	}
	338
	339	uschar *
	340	tls_cert_ocsp_uri(void * cert, uschar * mod)
	341	{
	342	#if GNUTLS_VERSION_NUMBER >= 0x030000
	343	gnutls_datum_t uri;
	344	int ret;
	345	uschar sep = '\n';
	346	gstring * list = NULL;
	347
	348	if (mod)
	349	if (mod == '>' && ++mod) sep = *mod++;
	350
	351	for (int index = 0;; index++)
	352	{
	353	ret = gnutls_x509_crt_get_authority_info_access((gnutls_x509_crt_t)cert,
	354	index, GNUTLS_IA_OCSP_URI, &uri, NULL);
	355
	356	if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
	357	return string_from_gstring(list);
	358	if (ret < 0)
	359	return g_err("gai", __FUNCTION__, ret);
	360
	361	list = string_append_listele_n(list, sep, uri.data, uri.size);
	362	}
	363	/NOTREACHED/
	364
	365	#else
	366
	367	expand_string_message =
	368	string_sprintf("%s: OCSP support with GnuTLS requires version 3.0.0\n",
	369	__FUNCTION__);
	370	return NULL;
	371
	372	#endif
	373	}
	374
	375	uschar *
	376	tls_cert_crl_uri(void * cert, uschar * mod)
	377	{
	378	int ret;
	379	uschar sep = '\n';
	380	gstring * list = NULL;
	381	uschar * ele;
	382
	383	if (mod)
	384	if (mod == '>' && ++mod) sep = *mod++;
	385
	386	for (int index = 0;; index++)
	387	{
	388	size_t siz = 0;
	389	switch(ret = gnutls_x509_crt_get_crl_dist_points(
	390	(gnutls_x509_crt_t)cert, index, NULL, &siz, NULL, NULL))
	391	{
	392	case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:
	393	return string_from_gstring(list);
	394	case GNUTLS_E_SHORT_MEMORY_BUFFER:
	395	break;
	396	default:
	397	return g_err("gc0", __FUNCTION__, ret);
	398	}
	399
	400	ele = store_get(siz);
	401	if ((ret = gnutls_x509_crt_get_crl_dist_points(
	402	(gnutls_x509_crt_t)cert, index, ele, &siz, NULL, NULL)) < 0)
	403	return g_err("gc1", __FUNCTION__, ret);
	404
	405	list = string_append_listele_n(list, sep, ele, siz);
	406	}
	407	/NOTREACHED/
	408	}
	409
	410
	411	/*****************************************************
	412	* Certificate operator routines
	413	*****************************************************/
	414	uschar *
	415	tls_cert_der_b64(void * cert)
	416	{
	417	size_t len = 0;
	418	uschar * cp = NULL;
	419	int fail;
	420
	421	if ( (fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
	422	GNUTLS_X509_FMT_DER, cp, &len)) != GNUTLS_E_SHORT_MEMORY_BUFFER
	423	\|\| !(cp = store_get((int)len))
	424	\|\| (fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
	425	GNUTLS_X509_FMT_DER, cp, &len))
	426	)
	427	{
	428	log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
	429	gnutls_strerror(fail));
	430	return NULL;
	431	}
	432	return b64encode(cp, (int)len);
	433	}
	434
	435
	436	static uschar *
	437	fingerprint(gnutls_x509_crt_t cert, gnutls_digest_algorithm_t algo)
	438	{
	439	int ret;
	440	size_t siz = 0;
	441	uschar * cp;
	442	uschar * cp2;
	443
	444	if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, NULL, &siz))
	445	!= GNUTLS_E_SHORT_MEMORY_BUFFER)
	446	return g_err("gf0", __FUNCTION__, ret);
	447
	448	cp = store_get(siz*3+1);
	449	if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, cp, &siz)) < 0)
	450	return g_err("gf1", __FUNCTION__, ret);
	451
	452	for (uschar * cp3 = cp2 = cp+siz; cp < cp2; cp++)
	453	cp3 += sprintf(CS cp3, "%02X", *cp);
	454	return cp2;
	455	}
	456
	457
	458	uschar *
	459	tls_cert_fprt_md5(void * cert)
	460	{
	461	return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_MD5);
	462	}
	463
	464	uschar *
	465	tls_cert_fprt_sha1(void * cert)
	466	{
	467	return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA1);
	468	}
	469
	470	uschar *
	471	tls_cert_fprt_sha256(void * cert)
	472	{
	473	return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA256);
	474	}
	475
	476
	477	/* vi: aw ai sw=2
	478	*/
	479	/* End of tlscert-gnu.c */