Documentation/Tests for CVE-2014-2972 fix

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

diff --git a/src/src/tlscert-gnu.c b/src/src/tlscert-gnu.c
index 3d255ee96aeefce147423008b259e7b4ffa0e497..3261c4e8d3075a5f1280cb782fec74d0a5a4189b 100644 (file)
--- a/src/src/tlscert-gnu.c
+++ b/src/src/tlscert-gnu.c
@@ -26,12 +26,16 @@ tls_export_cert(uschar * buf, size_t buflen, void * cert)
 {
 size_t sz = buflen;
 void * reset_point = store_get(0);
-int fail = 0;
+int fail;
 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;
+  }
 if ((cp = string_printing(buf)) != buf)
   {
   Ustrncpy(buf, cp, buflen);
@@ -55,8 +59,12 @@ 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;
+  }
 else
   *cert = (void *)crt;
 
@@ -74,47 +82,77 @@ gnutls_global_deinit();
 /*****************************************************
 *  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(stderr,
-  "%s: %s fail: %s\n", from, tag, gnutls_strerror(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)
+time_copy(time_t t, uschar * mod)
 {
-uschar * cp = store_get(32);
-struct tm * tp = gmtime(&t);
-size_t len = strftime(CS cp, 32, "%b %e %T %Y %Z", tp);
+uschar * cp;
+struct tm * tp;
+size_t len;
+
+if (mod && Ustrcmp(mod, "int") == 0)
+  return string_sprintf("%u", (unsigned)t);
+
+cp = store_get(32);
+tp = gmtime(&t);
+len = strftime(CS cp, 32, "%b %e %T %Y %Z", tp);
 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 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, 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, 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));
+  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));
+  gnutls_x509_crt_get_activation_time((gnutls_x509_crt_t)cert),
+  mod);
 }
 
 uschar *
@@ -124,10 +162,12 @@ uschar bin[50], txt[150];
 size_t sz = sizeof(bin);
 uschar * sp;
 uschar * dp;
+int ret;
+
+if ((ret = gnutls_x509_crt_get_serial((gnutls_x509_crt_t)cert,
+    bin, &sz)))
+  return g_err("gs0", __FUNCTION__, 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);
 for(sp = txt; sp[0]=='0' && sp[1]; ) sp++;     /* leading zeroes */
@@ -143,20 +183,13 @@ 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, 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, cp1, &len) != 0)
-  {
-  fprintf(stderr, "%s: gs1 fail\n", __FUNCTION__);
-  return NULL;
-  }
+  return g_err("gs1", __FUNCTION__, ret);
 
 for(cp3 = cp2 = cp1+len; cp1 < cp2; cp3 += 3, cp1++)
   sprintf(cp3, "%.2x ", *cp1);
@@ -180,23 +213,15 @@ uschar * cp = NULL;
 int ret;
 size_t siz = 0;
 
-ret = gnutls_x509_crt_get_dn(cert, cp, &siz);
-if (ret != GNUTLS_E_SHORT_MEMORY_BUFFER)
-  {
-  fprintf(stderr, "%s: gs0 fail: %s\n", __FUNCTION__, gnutls_strerror(ret));
-  return NULL;
-  }
+if ((ret = gnutls_x509_crt_get_dn(cert, 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, cp, &siz)) < 0)
+  return g_err("gs1", __FUNCTION__, ret);
 
-ret = gnutls_x509_crt_get_dn(cert, cp, &siz);
-if (ret < 0)
-  {
-  fprintf(stderr, "%s: gs1 fail: %s\n", __FUNCTION__, gnutls_strerror(ret));
-  return NULL;
-  }
-
-return cp;
+return mod ? tls_field_from_dn(cp, mod) : cp;
 }
 
 uschar *
@@ -265,7 +290,7 @@ for(index = 0;; index++)
   {
   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:
       return list;     /* no more elements; normal exit */
@@ -283,7 +308,8 @@ for(index = 0;; index++)
     return g_err("gs1", __FUNCTION__, ret);
   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)
     {