TLS: move from SUPPORT_TLS to DISABLE_TLS macro for the build

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

diff --git a/src/src/tlscert-gnu.c b/src/src/tlscert-gnu.c
index 5a4c231bb11de548cfcf0e751116f99deac4e2e8..cebeae526315da2bd876e54f46f04ce6b06e5771 100644 (file)
--- a/src/src/tlscert-gnu.c
+++ b/src/src/tlscert-gnu.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 

-/* Copyright (c) Jeremy Harris 2014 */
+/* 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
 
 /* This file provides TLS/SSL support for Exim using the GnuTLS library,
 one of the available supported implementations.  This file is #included into


@@ -26,12 +26,16 @@ tls_export_cert(uschar * buf, size_t buflen, void * cert)
 {
 size_t sz = buflen;
 void * reset_point = store_get(0);
 {
 size_t sz = buflen;
 void * reset_point = store_get(0);

-int fail = 0;
-uschar * cp;
+int fail;
+const uschar * cp;

 
 

-if (gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
-    GNUTLS_X509_FMT_PEM, buf, &sz))
+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;
   return 1;

+  }

 if ((cp = string_printing(buf)) != buf)
   {
   Ustrncpy(buf, cp, buflen);
 if ((cp = string_printing(buf)) != buf)
   {
   Ustrncpy(buf, cp, buflen);


@@ -47,16 +51,24 @@ tls_import_cert(const uschar * buf, void ** cert)
 {
 void * reset_point = store_get(0);
 gnutls_datum_t datum;
 {
 void * reset_point = store_get(0);
 gnutls_datum_t datum;

-gnutls_x509_crt_t crt;
+gnutls_x509_crt_t crt = *(gnutls_x509_crt_t *)cert;

 int fail = 0;
 
 int fail = 0;
 

-gnutls_global_init();
+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);
 gnutls_x509_crt_init(&crt);
 
 datum.data = string_unprinting(US buf);
 datum.size = Ustrlen(datum.data);

-if (gnutls_x509_crt_import(crt, &datum, GNUTLS_X509_FMT_PEM))
+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;
   fail = 1;

+  }

 else
   *cert = (void *)crt;
 
 else
   *cert = (void *)crt;
 


@@ -65,62 +77,112 @@ return fail;
 }
 
 void
 }
 
 void

-tls_free_cert(void * cert)
+tls_free_cert(void ** cert)

 {
 {

-gnutls_x509_crt_deinit((gnutls_x509_crt_t) cert);
-gnutls_global_deinit();
+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
 *****************************************************/
 }
 
 /*****************************************************
 *  Certificate field extraction routines
 *****************************************************/

+
+/* First, some internal service functions */
+

 static uschar *
 static uschar *

-time_copy(time_t t)
+g_err(const char * tag, const char * from, int gnutls_err)

 {
 {

-uschar * cp = store_get(32);
-struct tm * tp = gmtime(&t);
-size_t len = strftime(CS cp, 32, "%b %e %T %Y %Z", tp);
+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;
 }
 
 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 *
 tls_cert_issuer(void * cert, uschar * mod)
 {

-uschar txt[256];
-size_t sz = sizeof(txt);
-return ( gnutls_x509_crt_get_issuer_dn(cert, CS txt, &sz) == 0 )
-  ? string_copy(txt) : NULL;
+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(
 }
 
 uschar *
 tls_cert_not_after(void * cert, uschar * mod)
 {
 return time_copy(

-  gnutls_x509_crt_get_expiration_time((gnutls_x509_crt_t)cert));
+  gnutls_x509_crt_get_expiration_time((gnutls_x509_crt_t)cert),
+  mod);

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

-  gnutls_x509_crt_get_activation_time((gnutls_x509_crt_t)cert));
+  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 *
 tls_cert_serial_number(void * cert, uschar * mod)
 {
 uschar bin[50], txt[150];

+uschar * sp = bin;

 size_t sz = sizeof(bin);
 size_t sz = sizeof(bin);

-uschar * sp;
-uschar * dp;
+int ret;

 
 

-if (gnutls_x509_crt_get_serial((gnutls_x509_crt_t)cert,
-    bin, &sz) || sz > sizeof(bin))
-  return NULL;
-for(dp = txt, sp = bin; sz; dp += 2, sp++, sz--)
-  sprintf(dp, "%.2x", *sp);
+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);
 }
 for(sp = txt; sp[0]=='0' && sp[1]; ) sp++;     /* leading zeroes */
 return string_copy(sp);
 }


@@ -128,29 +190,22 @@ return string_copy(sp);
 uschar *
 tls_cert_signature(void * cert, uschar * mod)
 {
 uschar *
 tls_cert_signature(void * cert, uschar * mod)
 {

-uschar * cp1;
+uschar * cp1 = NULL;

 uschar * cp2;
 uschar * cp3;
 size_t len = 0;
 int ret;
 
 uschar * cp2;
 uschar * cp3;
 size_t len = 0;
 int ret;
 

-if ((ret = gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, cp1, &len)) !=
-       GNUTLS_E_SHORT_MEMORY_BUFFER)
-  {
-  fprintf(stderr, "%s: gs0 fail: %s\n", __FUNCTION__, gnutls_strerror(ret));
-  return NULL;
-  }
+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);
 
 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);

 
 

-if (gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, cp1, &len) != 0)
-  {
-  fprintf(stderr, "%s: gs1 fail\n", __FUNCTION__);
-  return NULL;
-  }
-
-for(cp3 = cp2 = cp1+len; cp1 < cp2; cp3 += 3, cp1++)
-  sprintf(cp3, "%.2x ", *cp1);
+for(cp3 = cp2 = cp1+len; cp1 < cp2; cp1++)
+  cp3 += sprintf(CS cp3, "%.2x ", *cp1);

 cp3[-1]= '\0';
 
 return cp2;
 cp3[-1]= '\0';
 
 return cp2;


@@ -161,16 +216,25 @@ tls_cert_signature_algorithm(void * cert, uschar * mod)
 {
 gnutls_sign_algorithm_t algo =
   gnutls_x509_crt_get_signature_algorithm((gnutls_x509_crt_t)cert);
 {
 gnutls_sign_algorithm_t algo =
   gnutls_x509_crt_get_signature_algorithm((gnutls_x509_crt_t)cert);

-return algo < 0 ? NULL : string_copy(gnutls_sign_get_name(algo));
+return algo < 0 ? NULL : string_copy(US gnutls_sign_get_name(algo));

 }
 
 uschar *
 tls_cert_subject(void * cert, uschar * mod)
 {
 }
 
 uschar *
 tls_cert_subject(void * cert, uschar * mod)
 {

-static uschar txt[256];
-size_t sz = sizeof(txt);
-return ( gnutls_x509_crt_get_dn(cert, CS txt, &sz) == 0 )
-  ? string_copy(txt) : NULL;
+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 *
 }
 
 uschar *


@@ -190,28 +254,22 @@ unsigned int crit;
 int ret;
 
 ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,
 int ret;
 
 ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,

-  oid, idx, cp1, &siz, &crit);
+  CS oid, idx, CS cp1, &siz, &crit);

 if (ret != GNUTLS_E_SHORT_MEMORY_BUFFER)
 if (ret != GNUTLS_E_SHORT_MEMORY_BUFFER)

-  {
-  fprintf(stderr, "%s: ge0 fail: %s\n", __FUNCTION__, gnutls_strerror(ret));
-  return NULL;
-  }
+  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,
 
 cp1 = store_get(siz*4 + 1);
 
 ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,

-  oid, idx, cp1, &siz, &crit);
+  CS oid, idx, CS cp1, &siz, &crit);

 if (ret < 0)
 if (ret < 0)

-  {
-  fprintf(stderr, "%s: ge1 fail: %s\n", __FUNCTION__, gnutls_strerror(ret));
-  return NULL;
-  }
+  return g_err("ge1", __FUNCTION__, ret);

 
 /* binary data, DER encoded */
 
 /* just dump for now */
 
 /* binary data, DER encoded */
 
 /* just dump for now */

-for(cp3 = cp2 = cp1+siz; cp1 < cp2; cp3 += 3, cp1++)
-  sprintf(cp3, "%.2x ", *cp1);
+for(cp3 = cp2 = cp1+siz; cp1 < cp2; cp1++)
+  cp3 += sprintf(CS cp3, "%.2x ", *cp1);

 cp3[-1]= '\0';
 
 return cp2;
 cp3[-1]= '\0';
 
 return cp2;


@@ -220,8 +278,7 @@ return cp2;
 uschar *
 tls_cert_subject_altname(void * cert, uschar * mod)
 {
 uschar *
 tls_cert_subject_altname(void * cert, uschar * mod)
 {

-uschar * list = NULL;
-int index;
+gstring * list = NULL;

 size_t siz;
 int ret;
 uschar sep = '\n';
 size_t siz;
 int ret;
 uschar sep = '\n';


@@ -241,46 +298,39 @@ while (mod)
     break;
   }
 
     break;
   }
 

-for(index = 0;; index++)
+for (int index = 0;; index++)

   {
   siz = 0;
   switch(ret = gnutls_x509_crt_get_subject_alt_name(
   {
   siz = 0;
   switch(ret = gnutls_x509_crt_get_subject_alt_name(

-    (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL))
+      (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL))

     {
     case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:
     {
     case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:

-      return list;     /* no more elements; normal exit */
+      return string_from_gstring(list);        /* no more elements; normal exit */

 
     case GNUTLS_E_SHORT_MEMORY_BUFFER:
       break;
 
     default:
 
     case GNUTLS_E_SHORT_MEMORY_BUFFER:
       break;
 
     default:

-      expand_string_message = 
-       string_sprintf("%s: gs0 fail: %d %s\n", __FUNCTION__,
-         ret, gnutls_strerror(ret));
-      return NULL;
+      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)
     }
 
   ele = store_get(siz+1);
   if ((ret = gnutls_x509_crt_get_subject_alt_name(
     (gnutls_x509_crt_t)cert, index, ele, &siz, NULL)) < 0)

-    {
-    expand_string_message = 
-      string_sprintf("%s: gs1 fail: %d %s\n", __FUNCTION__,
-       ret, gnutls_strerror(ret));
-    return NULL;
-    }
+    return g_err("gs1", __FUNCTION__, ret);

   ele[siz] = '\0';
 
   ele[siz] = '\0';
 

-  if (match != -1 && match != ret)
+  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;
     continue;
   switch (ret)
     {
     case GNUTLS_SAN_DNSNAME:    tag = US"DNS";  break;

-    case GNUTLS_SAN_URI:        tag = US"URI";  break; 
+    case GNUTLS_SAN_URI:        tag = US"URI";  break;

     case GNUTLS_SAN_RFC822NAME: tag = US"MAIL"; break;
     default: continue;        /* ignore unrecognised types */
     }
     case GNUTLS_SAN_RFC822NAME: tag = US"MAIL"; break;
     default: continue;        /* ignore unrecognised types */
     }

-  list = string_append_listele(list, sep, 
+  list = string_append_listele(list, sep,

           match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
   }
 /*NOTREACHED*/
           match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
   }
 /*NOTREACHED*/


@@ -293,35 +343,28 @@ tls_cert_ocsp_uri(void * cert, uschar * mod)
 gnutls_datum_t uri;
 int ret;
 uschar sep = '\n';
 gnutls_datum_t uri;
 int ret;
 uschar sep = '\n';

-int index;
-uschar * list = NULL;
+gstring * list = NULL;

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

-for(index = 0;; index++)
+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)
   {
   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 list;
+    return string_from_gstring(list);

   if (ret < 0)
   if (ret < 0)

-    {
-    expand_string_message = 
-      string_sprintf("%s: gai fail: %d %s\n", __FUNCTION__,
-       ret, gnutls_strerror(ret));
-    return NULL;
-    }
+    return g_err("gai", __FUNCTION__, ret);

 
 

-  list = string_append_listele(list, sep,
-           string_copyn(uri.data, uri.size));
+  list = string_append_listele_n(list, sep, uri.data, uri.size);

   }
 /*NOTREACHED*/
 
 #else
 
   }
 /*NOTREACHED*/
 
 #else
 

-expand_string_message = 
+expand_string_message =

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


@@ -333,43 +376,33 @@ uschar *
 tls_cert_crl_uri(void * cert, uschar * mod)
 {
 int ret;
 tls_cert_crl_uri(void * cert, uschar * mod)
 {
 int ret;

-size_t siz;

 uschar sep = '\n';
 uschar sep = '\n';

-int index;
-uschar * list = NULL;
+gstring * list = NULL;

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

-for(index = 0;; index++)
+for (int index = 0;; index++)

   {
   {

-  siz = 0;
+  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:
   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 list;
+      return string_from_gstring(list);

     case GNUTLS_E_SHORT_MEMORY_BUFFER:
       break;
     default:
     case GNUTLS_E_SHORT_MEMORY_BUFFER:
       break;
     default:

-      expand_string_message = 
-       string_sprintf("%s: gc0 fail: %d %s\n", __FUNCTION__,
-         ret, gnutls_strerror(ret));
-      return NULL;
+      return g_err("gc0", __FUNCTION__, ret);

     }
 
     }
 

-  ele = store_get(siz+1);
+  ele = store_get(siz);

   if ((ret = gnutls_x509_crt_get_crl_dist_points(
   if ((ret = gnutls_x509_crt_get_crl_dist_points(

-    (gnutls_x509_crt_t)cert, index, ele, &siz, NULL, NULL)) < 0)
-    {
-    expand_string_message = 
-      string_sprintf("%s: gc1 fail: %d %s\n", __FUNCTION__,
-       ret, gnutls_strerror(ret));
-    return NULL;
-    }
-  ele[siz] = '\0';
-  list = string_append_listele(list, sep, ele);
+      (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*/
 }
   }
 /*NOTREACHED*/
 }


@@ -378,6 +411,28 @@ for(index = 0;; index++)
 /*****************************************************
 *  Certificate operator routines
 *****************************************************/
 /*****************************************************
 *  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(CUS cp, (int)len);
+}
+
+

 static uschar *
 fingerprint(gnutls_x509_crt_t cert, gnutls_digest_algorithm_t algo)
 {
 static uschar *
 fingerprint(gnutls_x509_crt_t cert, gnutls_digest_algorithm_t algo)
 {


@@ -385,26 +440,17 @@ int ret;
 size_t siz = 0;
 uschar * cp;
 uschar * cp2;
 size_t siz = 0;
 uschar * cp;
 uschar * cp2;

-uschar * cp3;

 
 if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, NULL, &siz))
     != GNUTLS_E_SHORT_MEMORY_BUFFER)
 
 if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, NULL, &siz))
     != GNUTLS_E_SHORT_MEMORY_BUFFER)

-  {
-  expand_string_message = 
-    string_sprintf("%s: gf0 fail: %d %s\n", __FUNCTION__,
-      ret, gnutls_strerror(ret));
-  return NULL;
-  }
+  return g_err("gf0", __FUNCTION__, ret);
+

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

-  {
-  expand_string_message = 
-    string_sprintf("%s: gf1 fail: %d %s\n", __FUNCTION__,
-      ret, gnutls_strerror(ret));
-  return NULL;
-  }
-for (cp3 = cp2 = cp+siz; cp < cp2; cp++, cp3+=2)
-  sprintf(cp3, "%02X",*cp);
+  return g_err("gf1", __FUNCTION__, ret);
+
+for (uschar * cp3 = cp2 = cp+siz; cp < cp2; cp++)
+  cp3 += sprintf(CS cp3, "%02X", *cp);

 return cp2;
 }
 
 return cp2;
 }