Add 2012 to FSF copyright years for Emacs files
[bpt/emacs.git] / src / gnutls.c
index 38932c9..e7801ce 100644 (file)
@@ -1,5 +1,5 @@
 /* GnuTLS glue for GNU Emacs.
-   Copyright (C) 2010-2011  Free Software Foundation, Inc.
+   Copyright (C) 2010-2012  Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
 
@@ -26,55 +26,322 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #ifdef HAVE_GNUTLS
 #include <gnutls/gnutls.h>
 
-Lisp_Object Qgnutls_code;
-Lisp_Object Qgnutls_anon, Qgnutls_x509pki;
-Lisp_Object Qgnutls_e_interrupted, Qgnutls_e_again,
+#ifdef WINDOWSNT
+#include <windows.h>
+#include "w32.h"
+#endif
+
+static int
+emacs_gnutls_handle_error (gnutls_session_t, int err);
+
+static Lisp_Object Qgnutls_dll;
+static Lisp_Object Qgnutls_code;
+static Lisp_Object Qgnutls_anon, Qgnutls_x509pki;
+static Lisp_Object Qgnutls_e_interrupted, Qgnutls_e_again,
   Qgnutls_e_invalid_session, Qgnutls_e_not_ready_for_handshake;
-int global_initialized;
+static int gnutls_global_initialized;
 
 /* The following are for the property list of `gnutls-boot'.  */
-Lisp_Object Qgnutls_bootprop_priority;
-Lisp_Object Qgnutls_bootprop_trustfiles;
-Lisp_Object Qgnutls_bootprop_keyfiles;
-Lisp_Object Qgnutls_bootprop_callbacks;
-Lisp_Object Qgnutls_bootprop_loglevel;
+static Lisp_Object QCgnutls_bootprop_priority;
+static Lisp_Object QCgnutls_bootprop_trustfiles;
+static Lisp_Object QCgnutls_bootprop_keylist;
+static Lisp_Object QCgnutls_bootprop_crlfiles;
+static Lisp_Object QCgnutls_bootprop_callbacks;
+static Lisp_Object QCgnutls_bootprop_loglevel;
+static Lisp_Object QCgnutls_bootprop_hostname;
+static Lisp_Object QCgnutls_bootprop_min_prime_bits;
+static Lisp_Object QCgnutls_bootprop_verify_flags;
+static Lisp_Object QCgnutls_bootprop_verify_hostname_error;
+
+/* Callback keys for `gnutls-boot'.  Unused currently.  */
+static Lisp_Object QCgnutls_bootprop_callbacks_verify;
+
+static void gnutls_log_function (int, const char *);
+static void gnutls_log_function2 (int, const char*, const char*);
+
+\f
+#ifdef WINDOWSNT
+
+/* Macro for defining functions that will be loaded from the GnuTLS DLL.  */
+#define DEF_GNUTLS_FN(rettype,func,args) static rettype (FAR CDECL *fn_##func)args
+
+/* Macro for loading GnuTLS functions from the library.  */
+#define LOAD_GNUTLS_FN(lib,func) {                                     \
+    fn_##func = (void *) GetProcAddress (lib, #func);                  \
+    if (!fn_##func) return 0;                                          \
+  }
 
+DEF_GNUTLS_FN (gnutls_alert_description_t, gnutls_alert_get,
+              (gnutls_session_t));
+DEF_GNUTLS_FN (const char *, gnutls_alert_get_name,
+              (gnutls_alert_description_t));
+DEF_GNUTLS_FN (int, gnutls_alert_send_appropriate, (gnutls_session_t, int));
+DEF_GNUTLS_FN (int, gnutls_anon_allocate_client_credentials,
+              (gnutls_anon_client_credentials_t *));
+DEF_GNUTLS_FN (void, gnutls_anon_free_client_credentials,
+              (gnutls_anon_client_credentials_t));
+DEF_GNUTLS_FN (int, gnutls_bye, (gnutls_session_t, gnutls_close_request_t));
+DEF_GNUTLS_FN (int, gnutls_certificate_allocate_credentials,
+              (gnutls_certificate_credentials_t *));
+DEF_GNUTLS_FN (void, gnutls_certificate_free_credentials,
+              (gnutls_certificate_credentials_t));
+DEF_GNUTLS_FN (const gnutls_datum_t *, gnutls_certificate_get_peers,
+              (gnutls_session_t, unsigned int *));
+DEF_GNUTLS_FN (void, gnutls_certificate_set_verify_flags,
+              (gnutls_certificate_credentials_t, unsigned int));
+DEF_GNUTLS_FN (int, gnutls_certificate_set_x509_crl_file,
+              (gnutls_certificate_credentials_t, const char *,
+               gnutls_x509_crt_fmt_t));
+DEF_GNUTLS_FN (int, gnutls_certificate_set_x509_key_file,
+              (gnutls_certificate_credentials_t, const char *, const char *,
+               gnutls_x509_crt_fmt_t));
+DEF_GNUTLS_FN (int, gnutls_certificate_set_x509_trust_file,
+              (gnutls_certificate_credentials_t, const char *,
+               gnutls_x509_crt_fmt_t));
+DEF_GNUTLS_FN (gnutls_certificate_type_t, gnutls_certificate_type_get,
+              (gnutls_session_t));
+DEF_GNUTLS_FN (int, gnutls_certificate_verify_peers2,
+              (gnutls_session_t, unsigned int *));
+DEF_GNUTLS_FN (int, gnutls_credentials_set,
+              (gnutls_session_t, gnutls_credentials_type_t, void *));
+DEF_GNUTLS_FN (void, gnutls_deinit, (gnutls_session_t));
+DEF_GNUTLS_FN (void, gnutls_dh_set_prime_bits,
+              (gnutls_session_t, unsigned int));
+DEF_GNUTLS_FN (int, gnutls_error_is_fatal, (int));
+DEF_GNUTLS_FN (int, gnutls_global_init, (void));
+DEF_GNUTLS_FN (void, gnutls_global_set_log_function, (gnutls_log_func));
+DEF_GNUTLS_FN (void, gnutls_global_set_log_level, (int));
+DEF_GNUTLS_FN (void, gnutls_global_set_mem_functions,
+              (gnutls_alloc_function, gnutls_alloc_function,
+               gnutls_is_secure_function, gnutls_realloc_function,
+               gnutls_free_function));
+DEF_GNUTLS_FN (int, gnutls_handshake, (gnutls_session_t));
+DEF_GNUTLS_FN (int, gnutls_init, (gnutls_session_t *, gnutls_connection_end_t));
+DEF_GNUTLS_FN (int, gnutls_priority_set_direct,
+              (gnutls_session_t, const char *, const char **));
+DEF_GNUTLS_FN (size_t, gnutls_record_check_pending, (gnutls_session_t));
+DEF_GNUTLS_FN (ssize_t, gnutls_record_recv, (gnutls_session_t, void *, size_t));
+DEF_GNUTLS_FN (ssize_t, gnutls_record_send,
+              (gnutls_session_t, const void *, size_t));
+DEF_GNUTLS_FN (const char *, gnutls_strerror, (int));
+DEF_GNUTLS_FN (void, gnutls_transport_set_errno, (gnutls_session_t, int));
+DEF_GNUTLS_FN (const char *, gnutls_check_version, (const char *));
+DEF_GNUTLS_FN (void, gnutls_transport_set_lowat, (gnutls_session_t, int));
+DEF_GNUTLS_FN (void, gnutls_transport_set_ptr2,
+              (gnutls_session_t, gnutls_transport_ptr_t,
+               gnutls_transport_ptr_t));
+DEF_GNUTLS_FN (void, gnutls_transport_set_pull_function,
+              (gnutls_session_t, gnutls_pull_func));
+DEF_GNUTLS_FN (void, gnutls_transport_set_push_function,
+              (gnutls_session_t, gnutls_push_func));
+DEF_GNUTLS_FN (int, gnutls_x509_crt_check_hostname,
+              (gnutls_x509_crt_t, const char *));
+DEF_GNUTLS_FN (void, gnutls_x509_crt_deinit, (gnutls_x509_crt_t));
+DEF_GNUTLS_FN (int, gnutls_x509_crt_import,
+              (gnutls_x509_crt_t, const gnutls_datum_t *,
+               gnutls_x509_crt_fmt_t));
+DEF_GNUTLS_FN (int, gnutls_x509_crt_init, (gnutls_x509_crt_t *));
+
+static int
+init_gnutls_functions (Lisp_Object libraries)
+{
+  HMODULE library;
+  int max_log_level = 1;
+
+  if (!(library = w32_delayed_load (libraries, Qgnutls_dll)))
+    {
+      GNUTLS_LOG (1, max_log_level, "GnuTLS library not found");
+      return 0;
+    }
+
+  LOAD_GNUTLS_FN (library, gnutls_alert_get);
+  LOAD_GNUTLS_FN (library, gnutls_alert_get_name);
+  LOAD_GNUTLS_FN (library, gnutls_alert_send_appropriate);
+  LOAD_GNUTLS_FN (library, gnutls_anon_allocate_client_credentials);
+  LOAD_GNUTLS_FN (library, gnutls_anon_free_client_credentials);
+  LOAD_GNUTLS_FN (library, gnutls_bye);
+  LOAD_GNUTLS_FN (library, gnutls_certificate_allocate_credentials);
+  LOAD_GNUTLS_FN (library, gnutls_certificate_free_credentials);
+  LOAD_GNUTLS_FN (library, gnutls_certificate_get_peers);
+  LOAD_GNUTLS_FN (library, gnutls_certificate_set_verify_flags);
+  LOAD_GNUTLS_FN (library, gnutls_certificate_set_x509_crl_file);
+  LOAD_GNUTLS_FN (library, gnutls_certificate_set_x509_key_file);
+  LOAD_GNUTLS_FN (library, gnutls_certificate_set_x509_trust_file);
+  LOAD_GNUTLS_FN (library, gnutls_certificate_type_get);
+  LOAD_GNUTLS_FN (library, gnutls_certificate_verify_peers2);
+  LOAD_GNUTLS_FN (library, gnutls_credentials_set);
+  LOAD_GNUTLS_FN (library, gnutls_deinit);
+  LOAD_GNUTLS_FN (library, gnutls_dh_set_prime_bits);
+  LOAD_GNUTLS_FN (library, gnutls_error_is_fatal);
+  LOAD_GNUTLS_FN (library, gnutls_global_init);
+  LOAD_GNUTLS_FN (library, gnutls_global_set_log_function);
+  LOAD_GNUTLS_FN (library, gnutls_global_set_log_level);
+  LOAD_GNUTLS_FN (library, gnutls_global_set_mem_functions);
+  LOAD_GNUTLS_FN (library, gnutls_handshake);
+  LOAD_GNUTLS_FN (library, gnutls_init);
+  LOAD_GNUTLS_FN (library, gnutls_priority_set_direct);
+  LOAD_GNUTLS_FN (library, gnutls_record_check_pending);
+  LOAD_GNUTLS_FN (library, gnutls_record_recv);
+  LOAD_GNUTLS_FN (library, gnutls_record_send);
+  LOAD_GNUTLS_FN (library, gnutls_strerror);
+  LOAD_GNUTLS_FN (library, gnutls_transport_set_errno);
+  LOAD_GNUTLS_FN (library, gnutls_check_version);
+  /* We don't need to call gnutls_transport_set_lowat in GnuTLS 2.11.1
+     and later, and the function was removed entirely in 3.0.0.  */
+  if (!fn_gnutls_check_version ("2.11.1"))
+    LOAD_GNUTLS_FN (library, gnutls_transport_set_lowat);
+  LOAD_GNUTLS_FN (library, gnutls_transport_set_ptr2);
+  LOAD_GNUTLS_FN (library, gnutls_transport_set_pull_function);
+  LOAD_GNUTLS_FN (library, gnutls_transport_set_push_function);
+  LOAD_GNUTLS_FN (library, gnutls_x509_crt_check_hostname);
+  LOAD_GNUTLS_FN (library, gnutls_x509_crt_deinit);
+  LOAD_GNUTLS_FN (library, gnutls_x509_crt_import);
+  LOAD_GNUTLS_FN (library, gnutls_x509_crt_init);
+
+  max_log_level = global_gnutls_log_level;
+
+  GNUTLS_LOG2 (1, max_log_level, "GnuTLS library loaded:",
+              SDATA (Fget (Qgnutls_dll, QCloaded_from)));
+  return 1;
+}
+
+#else /* !WINDOWSNT */
+
+#define fn_gnutls_alert_get                    gnutls_alert_get
+#define fn_gnutls_alert_get_name               gnutls_alert_get_name
+#define fn_gnutls_alert_send_appropriate       gnutls_alert_send_appropriate
+#define fn_gnutls_anon_allocate_client_credentials gnutls_anon_allocate_client_credentials
+#define fn_gnutls_anon_free_client_credentials gnutls_anon_free_client_credentials
+#define fn_gnutls_bye                          gnutls_bye
+#define fn_gnutls_certificate_allocate_credentials gnutls_certificate_allocate_credentials
+#define fn_gnutls_certificate_free_credentials gnutls_certificate_free_credentials
+#define fn_gnutls_certificate_get_peers                gnutls_certificate_get_peers
+#define fn_gnutls_certificate_set_verify_flags gnutls_certificate_set_verify_flags
+#define fn_gnutls_certificate_set_x509_crl_file        gnutls_certificate_set_x509_crl_file
+#define fn_gnutls_certificate_set_x509_key_file gnutls_certificate_set_x509_key_file
+#define fn_gnutls_certificate_set_x509_trust_file gnutls_certificate_set_x509_trust_file
+#define fn_gnutls_certificate_type_get         gnutls_certificate_type_get
+#define fn_gnutls_certificate_verify_peers2    gnutls_certificate_verify_peers2
+#define fn_gnutls_credentials_set              gnutls_credentials_set
+#define fn_gnutls_deinit                       gnutls_deinit
+#define fn_gnutls_dh_set_prime_bits            gnutls_dh_set_prime_bits
+#define fn_gnutls_error_is_fatal               gnutls_error_is_fatal
+#define fn_gnutls_global_init                  gnutls_global_init
+#define fn_gnutls_global_set_log_function      gnutls_global_set_log_function
+#define fn_gnutls_global_set_log_level         gnutls_global_set_log_level
+#define fn_gnutls_global_set_mem_functions     gnutls_global_set_mem_functions
+#define fn_gnutls_handshake                    gnutls_handshake
+#define fn_gnutls_init                         gnutls_init
+#define fn_gnutls_priority_set_direct          gnutls_priority_set_direct
+#define fn_gnutls_record_check_pending         gnutls_record_check_pending
+#define fn_gnutls_record_recv                  gnutls_record_recv
+#define fn_gnutls_record_send                  gnutls_record_send
+#define fn_gnutls_strerror                     gnutls_strerror
+#define fn_gnutls_transport_set_errno          gnutls_transport_set_errno
+#define fn_gnutls_transport_set_ptr2           gnutls_transport_set_ptr2
+#define fn_gnutls_x509_crt_check_hostname      gnutls_x509_crt_check_hostname
+#define fn_gnutls_x509_crt_deinit              gnutls_x509_crt_deinit
+#define fn_gnutls_x509_crt_import              gnutls_x509_crt_import
+#define fn_gnutls_x509_crt_init                        gnutls_x509_crt_init
+
+#endif /* !WINDOWSNT */
+
+\f
 static void
+gnutls_log_function (int level, const char* string)
+{
+  message ("gnutls.c: [%d] %s", level, string);
+}
+
+static void
+gnutls_log_function2 (int level, const char* string, const char* extra)
+{
+  message ("gnutls.c: [%d] %s %s", level, string, extra);
+}
+
+static int
 emacs_gnutls_handshake (struct Lisp_Process *proc)
 {
   gnutls_session_t state = proc->gnutls_state;
   int ret;
 
   if (proc->gnutls_initstage < GNUTLS_STAGE_HANDSHAKE_CANDO)
-    return;
+    return -1;
 
   if (proc->gnutls_initstage < GNUTLS_STAGE_TRANSPORT_POINTERS_SET)
     {
+#ifdef WINDOWSNT
+      /* On W32 we cannot transfer socket handles between different runtime
+        libraries, so we tell GnuTLS to use our special push/pull
+        functions.  */
+      fn_gnutls_transport_set_ptr2 (state,
+                                   (gnutls_transport_ptr_t) proc,
+                                   (gnutls_transport_ptr_t) proc);
+      fn_gnutls_transport_set_push_function (state, &emacs_gnutls_push);
+      fn_gnutls_transport_set_pull_function (state, &emacs_gnutls_pull);
+
+      /* For non blocking sockets or other custom made pull/push
+        functions the gnutls_transport_set_lowat must be called, with
+        a zero low water mark value. (GnuTLS 2.10.4 documentation)
+
+        (Note: this is probably not strictly necessary as the lowat
+         value is only used when no custom pull/push functions are
+         set.)  */
+      /* According to GnuTLS NEWS file, lowat level has been set to
+        zero by default in version 2.11.1, and the function
+        gnutls_transport_set_lowat was removed from the library in
+        version 2.99.0.  */
+      if (!fn_gnutls_check_version ("2.11.1"))
+       fn_gnutls_transport_set_lowat (state, 0);
+#else
       /* This is how GnuTLS takes sockets: as file descriptors passed
-         in.  For an Emacs process socket, infd and outfd are the
-         same but we use this two-argument version for clarity.  */
-      gnutls_transport_set_ptr2 (state,
-                                (gnutls_transport_ptr_t) (long) proc->infd,
-                                (gnutls_transport_ptr_t) (long) proc->outfd);
+        in.  For an Emacs process socket, infd and outfd are the
+        same but we use this two-argument version for clarity.  */
+      fn_gnutls_transport_set_ptr2 (state,
+                                   (gnutls_transport_ptr_t) (long) proc->infd,
+                                   (gnutls_transport_ptr_t) (long) proc->outfd);
+#endif
 
       proc->gnutls_initstage = GNUTLS_STAGE_TRANSPORT_POINTERS_SET;
     }
 
-  ret = gnutls_handshake (state);
+  do
+    {
+      ret = fn_gnutls_handshake (state);
+      emacs_gnutls_handle_error (state, ret);
+    }
+  while (ret < 0 && fn_gnutls_error_is_fatal (ret) == 0);
+
   proc->gnutls_initstage = GNUTLS_STAGE_HANDSHAKE_TRIED;
 
   if (ret == GNUTLS_E_SUCCESS)
     {
-      /* here we're finally done.  */
+      /* Here we're finally done.  */
       proc->gnutls_initstage = GNUTLS_STAGE_READY;
     }
+  else
+    {
+      fn_gnutls_alert_send_appropriate (state, ret);
+    }
+  return ret;
+}
+
+int
+emacs_gnutls_record_check_pending (gnutls_session_t state)
+{
+  return fn_gnutls_record_check_pending (state);
+}
+
+void
+emacs_gnutls_transport_set_errno (gnutls_session_t state, int err)
+{
+  fn_gnutls_transport_set_errno (state, err);
 }
 
 EMACS_INT
-emacs_gnutls_write (int fildes, struct Lisp_Process *proc, const char *buf,
-                    EMACS_INT nbyte)
+emacs_gnutls_write (struct Lisp_Process *proc, const char *buf, EMACS_INT nbyte)
 {
-  ssize_t rtnval;
+  ssize_t rtnval = 0;
   EMACS_INT bytes_written;
   gnutls_session_t state = proc->gnutls_state;
 
@@ -92,27 +359,27 @@ emacs_gnutls_write (int fildes, struct Lisp_Process *proc, const char *buf,
 
   while (nbyte > 0)
     {
-      rtnval = gnutls_write (state, buf, nbyte);
+      rtnval = fn_gnutls_record_send (state, buf, nbyte);
 
       if (rtnval < 0)
-        {
-          if (rtnval == GNUTLS_E_AGAIN || rtnval == GNUTLS_E_INTERRUPTED)
-            continue;
-          else
-            break;
-        }
+       {
+         if (rtnval == GNUTLS_E_AGAIN || rtnval == GNUTLS_E_INTERRUPTED)
+           continue;
+         else
+           break;
+       }
 
       buf += rtnval;
       nbyte -= rtnval;
       bytes_written += rtnval;
     }
 
+  emacs_gnutls_handle_error (state, rtnval);
   return (bytes_written);
 }
 
 EMACS_INT
-emacs_gnutls_read (int fildes, struct Lisp_Process *proc, char *buf,
-                   EMACS_INT nbyte)
+emacs_gnutls_read (struct Lisp_Process *proc, char *buf, EMACS_INT nbyte)
 {
   ssize_t rtnval;
   gnutls_session_t state = proc->gnutls_state;
@@ -122,19 +389,69 @@ emacs_gnutls_read (int fildes, struct Lisp_Process *proc, char *buf,
       emacs_gnutls_handshake (proc);
       return -1;
     }
-
-  rtnval = gnutls_read (state, buf, nbyte);
+  rtnval = fn_gnutls_record_recv (state, buf, nbyte);
   if (rtnval >= 0)
     return rtnval;
+  else if (rtnval == GNUTLS_E_UNEXPECTED_PACKET_LENGTH)
+    /* The peer closed the connection. */
+    return 0;
+  else if (emacs_gnutls_handle_error (state, rtnval) == 0)
+    /* non-fatal error */
+    return -1;
   else {
-    if (rtnval == GNUTLS_E_AGAIN ||
-       rtnval == GNUTLS_E_INTERRUPTED)
-      return -1;
-    else
-      return 0;
+    /* a fatal error occurred */
+    return 0;
   }
 }
 
+/* report a GnuTLS error to the user.
+   Returns zero if the error code was successfully handled. */
+static int
+emacs_gnutls_handle_error (gnutls_session_t session, int err)
+{
+  int max_log_level = 0;
+
+  int ret;
+  const char *str;
+
+  /* TODO: use a Lisp_Object generated by gnutls_make_error?  */
+  if (err >= 0)
+    return 0;
+
+  max_log_level = global_gnutls_log_level;
+
+  /* TODO: use gnutls-error-fatalp and gnutls-error-string.  */
+
+  str = fn_gnutls_strerror (err);
+  if (!str)
+    str = "unknown";
+
+  if (fn_gnutls_error_is_fatal (err))
+    {
+      ret = err;
+      GNUTLS_LOG2 (0, max_log_level, "fatal error:", str);
+    }
+  else
+    {
+      ret = 0;
+      GNUTLS_LOG2 (1, max_log_level, "non-fatal error:", str);
+      /* TODO: EAGAIN AKA Qgnutls_e_again should be level 2.  */
+    }
+
+  if (err == GNUTLS_E_WARNING_ALERT_RECEIVED
+      || err == GNUTLS_E_FATAL_ALERT_RECEIVED)
+    {
+      int alert = fn_gnutls_alert_get (session);
+      int level = (err == GNUTLS_E_FATAL_ALERT_RECEIVED) ? 0 : 1;
+      str = fn_gnutls_alert_get_name (alert);
+      if (!str)
+       str = "unknown";
+
+      GNUTLS_LOG2 (level, max_log_level, "Received alert: ", str);
+    }
+  return ret;
+}
+
 /* convert an integer error to a Lisp_Object; it will be either a
    known symbol like `gnutls_e_interrupted' and `gnutls_e_again' or
    simply the integer value of the error.  GNUTLS_E_SUCCESS is mapped
@@ -157,6 +474,44 @@ gnutls_make_error (int err)
   return make_number (err);
 }
 
+Lisp_Object
+emacs_gnutls_deinit (Lisp_Object proc)
+{
+  int log_level;
+
+  CHECK_PROCESS (proc);
+
+  if (XPROCESS (proc)->gnutls_p == 0)
+    return Qnil;
+
+  log_level = XPROCESS (proc)->gnutls_log_level;
+
+  if (XPROCESS (proc)->gnutls_x509_cred)
+    {
+      GNUTLS_LOG (2, log_level, "Deallocating x509 credentials");
+      fn_gnutls_certificate_free_credentials (XPROCESS (proc)->gnutls_x509_cred);
+      XPROCESS (proc)->gnutls_x509_cred = NULL;
+    }
+
+  if (XPROCESS (proc)->gnutls_anon_cred)
+    {
+      GNUTLS_LOG (2, log_level, "Deallocating anon credentials");
+      fn_gnutls_anon_free_client_credentials (XPROCESS (proc)->gnutls_anon_cred);
+      XPROCESS (proc)->gnutls_anon_cred = NULL;
+    }
+
+  if (XPROCESS (proc)->gnutls_state)
+    {
+      fn_gnutls_deinit (XPROCESS (proc)->gnutls_state);
+      XPROCESS (proc)->gnutls_state = NULL;
+      if (GNUTLS_INITSTAGE (proc) >= GNUTLS_STAGE_INIT)
+       GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_INIT - 1;
+    }
+
+  XPROCESS (proc)->gnutls_p = 0;
+  return Qt;
+}
+
 DEFUN ("gnutls-get-initstage", Fgnutls_get_initstage, Sgnutls_get_initstage, 1, 1, 0,
        doc: /* Return the GnuTLS init stage of process PROC.
 See also `gnutls-boot'.  */)
@@ -204,7 +559,7 @@ usage: (gnutls-error-fatalp ERROR)  */)
   if (!NUMBERP (err))
     error ("Not an error symbol or code");
 
-  if (0 == gnutls_error_is_fatal (XINT (err)))
+  if (0 == fn_gnutls_error_is_fatal (XINT (err)))
     return Qnil;
 
   return Qt;
@@ -236,7 +591,7 @@ usage: (gnutls-error-string ERROR)  */)
   if (!NUMBERP (err))
     return build_string ("Not an error symbol or code");
 
-  return build_string (gnutls_strerror (XINT (err)));
+  return build_string (fn_gnutls_strerror (XINT (err)));
 }
 
 DEFUN ("gnutls-deinit", Fgnutls_deinit, Sgnutls_deinit, 1, 1, 0,
@@ -244,32 +599,45 @@ DEFUN ("gnutls-deinit", Fgnutls_deinit, Sgnutls_deinit, 1, 1, 0,
 See also `gnutls-init'.  */)
   (Lisp_Object proc)
 {
-  gnutls_session_t state;
-
-  CHECK_PROCESS (proc);
-  state = XPROCESS (proc)->gnutls_state;
+  return emacs_gnutls_deinit (proc);
+}
 
-  if (GNUTLS_INITSTAGE (proc) >= GNUTLS_STAGE_INIT)
+DEFUN ("gnutls-available-p", Fgnutls_available_p, Sgnutls_available_p, 0, 0, 0,
+       doc: /* Return t if GnuTLS is available in this instance of Emacs.  */)
+     (void)
+{
+#ifdef WINDOWSNT
+  Lisp_Object found = Fassq (Qgnutls_dll, Vlibrary_cache);
+  if (CONSP (found))
+    return XCDR (found);
+  else
     {
-      gnutls_deinit (state);
-      GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_INIT - 1;
+      Lisp_Object status;
+      status = init_gnutls_functions (Vdynamic_library_alist) ? Qt : Qnil;
+      Vlibrary_cache = Fcons (Fcons (Qgnutls_dll, status), Vlibrary_cache);
+      return status;
     }
-
+#else
   return Qt;
+#endif
 }
 
+
 /* Initializes global GnuTLS state to defaults.
 Call `gnutls-global-deinit' when GnuTLS usage is no longer needed.
 Returns zero on success.  */
 static Lisp_Object
-gnutls_emacs_global_init (void)
+emacs_gnutls_global_init (void)
 {
   int ret = GNUTLS_E_SUCCESS;
 
-  if (!global_initialized)
-    ret = gnutls_global_init ();
-
-  global_initialized = 1;
+  if (!gnutls_global_initialized)
+    {
+      fn_gnutls_global_set_mem_functions (xmalloc, xmalloc, NULL,
+                                         xrealloc, xfree);
+      ret = fn_gnutls_global_init ();
+    }
+  gnutls_global_initialized = 1;
 
   return gnutls_make_error (ret);
 }
@@ -278,43 +646,49 @@ gnutls_emacs_global_init (void)
 /* Deinitializes global GnuTLS state.
 See also `gnutls-global-init'.  */
 static Lisp_Object
-gnutls_emacs_global_deinit (void)
+emacs_gnutls_global_deinit (void)
 {
-  if (global_initialized)
+  if (gnutls_global_initialized)
     gnutls_global_deinit ();
 
-  global_initialized = 0;
+  gnutls_global_initialized = 0;
 
   return gnutls_make_error (GNUTLS_E_SUCCESS);
 }
 #endif
 
-static void
-gnutls_log_function (int level, const char* string)
-{
-  message ("gnutls.c: [%d] %s", level, string);
-}
-
-static void
-gnutls_log_function2 (int level, const char* string, const char* extra)
-{
-  message ("gnutls.c: [%d] %s %s", level, string, extra);
-}
-
 DEFUN ("gnutls-boot", Fgnutls_boot, Sgnutls_boot, 3, 3, 0,
        doc: /* Initialize GnuTLS client for process PROC with TYPE+PROPLIST.
-Currently only client mode is supported.  Returns a success/failure
+Currently only client mode is supported.  Return a success/failure
 value you can check with `gnutls-errorp'.
 
 TYPE is a symbol, either `gnutls-anon' or `gnutls-x509pki'.
 PROPLIST is a property list with the following keys:
 
+:hostname is a string naming the remote host.
+
 :priority is a GnuTLS priority string, defaults to "NORMAL".
+
 :trustfiles is a list of PEM-encoded trust files for `gnutls-x509pki'.
-:keyfiles is a list of PEM-encoded key files for `gnutls-x509pki'.
-:callbacks is an alist of callback functions (TODO).
+
+:crlfiles is a list of PEM-encoded CRL lists for `gnutls-x509pki'.
+
+:keylist is an alist of PEM-encoded key files and PEM-encoded
+certificates for `gnutls-x509pki'.
+
+:callbacks is an alist of callback functions, see below.
+
 :loglevel is the debug level requested from GnuTLS, try 4.
 
+:verify-flags is a bitset as per GnuTLS'
+gnutls_certificate_set_verify_flags.
+
+:verify-hostname-error, if non-nil, makes a hostname mismatch an
+error.  Otherwise it will be just a warning.
+
+:min-prime-bits is the minimum accepted number of bits the client will
+accept in Diffie-Hellman key exchange.
+
 The debug level will be set for this process AND globally for GnuTLS.
 So if you set it higher or lower at any point, it affects global
 debugging.
@@ -327,226 +701,345 @@ Processes must be initialized with this function before other GnuTLS
 functions are used.  This function allocates resources which can only
 be deallocated by calling `gnutls-deinit' or by calling it again.
 
+The callbacks alist can have a `verify' key, associated with a
+verification function (UNUSED).
+
 Each authentication type may need additional information in order to
 work.  For X.509 PKI (`gnutls-x509pki'), you probably need at least
 one trustfile (usually a CA bundle).  */)
   (Lisp_Object proc, Lisp_Object type, Lisp_Object proplist)
 {
   int ret = GNUTLS_E_SUCCESS;
-
   int max_log_level = 0;
 
-  /* TODO: GNUTLS_X509_FMT_DER is also an option.  */
-  int file_format = GNUTLS_X509_FMT_PEM;
-
   gnutls_session_t state;
-  gnutls_certificate_credentials_t x509_cred;
-  gnutls_anon_client_credentials_t anon_cred;
+  gnutls_certificate_credentials_t x509_cred = NULL;
+  gnutls_anon_client_credentials_t anon_cred = NULL;
   Lisp_Object global_init;
   char const *priority_string_ptr = "NORMAL"; /* default priority string.  */
-  Lisp_Object tail;
+  unsigned int peer_verification;
+  char* c_hostname;
 
   /* Placeholders for the property list elements.  */
   Lisp_Object priority_string;
   Lisp_Object trustfiles;
-  Lisp_Object keyfiles;
+  Lisp_Object crlfiles;
+  Lisp_Object keylist;
   /* Lisp_Object callbacks; */
   Lisp_Object loglevel;
+  Lisp_Object hostname;
+  /* Lisp_Object verify_error; */
+  Lisp_Object verify_hostname_error;
+  Lisp_Object prime_bits;
 
   CHECK_PROCESS (proc);
   CHECK_SYMBOL (type);
   CHECK_LIST (proplist);
 
-  priority_string = Fplist_get (proplist, Qgnutls_bootprop_priority);
-  trustfiles      = Fplist_get (proplist, Qgnutls_bootprop_trustfiles);
-  keyfiles        = Fplist_get (proplist, Qgnutls_bootprop_keyfiles);
-  /* callbacks       = Fplist_get (proplist, Qgnutls_bootprop_callbacks); */
-  loglevel        = Fplist_get (proplist, Qgnutls_bootprop_loglevel);
+  if (NILP (Fgnutls_available_p ()))
+    {
+      error ("GnuTLS not available");
+      return gnutls_make_error (GNUTLS_EMACS_ERROR_NOT_LOADED);
+    }
 
-  state = XPROCESS (proc)->gnutls_state;
-  XPROCESS (proc)->gnutls_p = 1;
+  if (!EQ (type, Qgnutls_x509pki) && !EQ (type, Qgnutls_anon))
+    {
+      error ("Invalid GnuTLS credential type");
+      return gnutls_make_error (GNUTLS_EMACS_ERROR_INVALID_TYPE);
+    }
+
+  hostname              = Fplist_get (proplist, QCgnutls_bootprop_hostname);
+  priority_string       = Fplist_get (proplist, QCgnutls_bootprop_priority);
+  trustfiles            = Fplist_get (proplist, QCgnutls_bootprop_trustfiles);
+  keylist               = Fplist_get (proplist, QCgnutls_bootprop_keylist);
+  crlfiles              = Fplist_get (proplist, QCgnutls_bootprop_crlfiles);
+  loglevel              = Fplist_get (proplist, QCgnutls_bootprop_loglevel);
+  verify_hostname_error = Fplist_get (proplist, QCgnutls_bootprop_verify_hostname_error);
+  prime_bits            = Fplist_get (proplist, QCgnutls_bootprop_min_prime_bits);
+
+  if (!STRINGP (hostname))
+    error ("gnutls-boot: invalid :hostname parameter");
+  c_hostname = SSDATA (hostname);
 
   if (NUMBERP (loglevel))
     {
-      gnutls_global_set_log_function (gnutls_log_function);
-      gnutls_global_set_log_level (XINT (loglevel));
+      fn_gnutls_global_set_log_function (gnutls_log_function);
+      fn_gnutls_global_set_log_level (XINT (loglevel));
       max_log_level = XINT (loglevel);
       XPROCESS (proc)->gnutls_log_level = max_log_level;
     }
 
   /* always initialize globals.  */
-  global_init = gnutls_emacs_global_init ();
+  global_init = emacs_gnutls_global_init ();
   if (! NILP (Fgnutls_errorp (global_init)))
     return global_init;
 
-  /* deinit and free resources.  */
-  if (GNUTLS_INITSTAGE (proc) >= GNUTLS_STAGE_CRED_ALLOC)
-    {
-      GNUTLS_LOG (1, max_log_level, "deallocating credentials");
-
-      if (EQ (type, Qgnutls_x509pki))
-       {
-          GNUTLS_LOG (2, max_log_level, "deallocating x509 credentials");
-          x509_cred = XPROCESS (proc)->gnutls_x509_cred;
-          gnutls_certificate_free_credentials (x509_cred);
-       }
-      else if (EQ (type, Qgnutls_anon))
-       {
-          GNUTLS_LOG (2, max_log_level, "deallocating anon credentials");
-          anon_cred = XPROCESS (proc)->gnutls_anon_cred;
-          gnutls_anon_free_client_credentials (anon_cred);
-       }
-      else
-       {
-          error ("unknown credential type");
-          ret = GNUTLS_EMACS_ERROR_INVALID_TYPE;
-       }
-
-      if (GNUTLS_INITSTAGE (proc) >= GNUTLS_STAGE_INIT)
-       {
-          GNUTLS_LOG (1, max_log_level, "deallocating x509 credentials");
-          Fgnutls_deinit (proc);
-       }
-    }
+  /* Before allocating new credentials, deallocate any credentials
+     that PROC might already have.  */
+  emacs_gnutls_deinit (proc);
 
+  /* Mark PROC as a GnuTLS process.  */
+  XPROCESS (proc)->gnutls_p = 1;
+  XPROCESS (proc)->gnutls_state = NULL;
+  XPROCESS (proc)->gnutls_x509_cred = NULL;
+  XPROCESS (proc)->gnutls_anon_cred = NULL;
+  XPROCESS (proc)->gnutls_cred_type = type;
   GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_EMPTY;
 
   GNUTLS_LOG (1, max_log_level, "allocating credentials");
-
   if (EQ (type, Qgnutls_x509pki))
     {
+      Lisp_Object verify_flags;
+      unsigned int gnutls_verify_flags = GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT;
+
       GNUTLS_LOG (2, max_log_level, "allocating x509 credentials");
-      x509_cred = XPROCESS (proc)->gnutls_x509_cred;
-      if (gnutls_certificate_allocate_credentials (&x509_cred) < 0)
-        memory_full ();
+      fn_gnutls_certificate_allocate_credentials (&x509_cred);
+      XPROCESS (proc)->gnutls_x509_cred = x509_cred;
+
+      verify_flags = Fplist_get (proplist, QCgnutls_bootprop_verify_flags);
+      if (NUMBERP (verify_flags))
+       {
+         gnutls_verify_flags = XINT (verify_flags);
+         GNUTLS_LOG (2, max_log_level, "setting verification flags");
+       }
+      else if (NILP (verify_flags))
+       GNUTLS_LOG (2, max_log_level, "using default verification flags");
+      else
+       GNUTLS_LOG (2, max_log_level, "ignoring invalid verify-flags");
+
+      fn_gnutls_certificate_set_verify_flags (x509_cred, gnutls_verify_flags);
     }
-  else if (EQ (type, Qgnutls_anon))
+  else /* Qgnutls_anon: */
     {
       GNUTLS_LOG (2, max_log_level, "allocating anon credentials");
-      anon_cred = XPROCESS (proc)->gnutls_anon_cred;
-      if (gnutls_anon_allocate_client_credentials (&anon_cred) < 0)
-        memory_full ();
+      fn_gnutls_anon_allocate_client_credentials (&anon_cred);
+      XPROCESS (proc)->gnutls_anon_cred = anon_cred;
     }
-  else
-    {
-      error ("unknown credential type");
-      ret = GNUTLS_EMACS_ERROR_INVALID_TYPE;
-    }
-
-  if (ret < GNUTLS_E_SUCCESS)
-    return gnutls_make_error (ret);
 
   GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_CRED_ALLOC;
 
   if (EQ (type, Qgnutls_x509pki))
     {
+      /* TODO: GNUTLS_X509_FMT_DER is also an option.  */
+      int file_format = GNUTLS_X509_FMT_PEM;
+      Lisp_Object tail;
+
       for (tail = trustfiles; !NILP (tail); tail = Fcdr (tail))
        {
          Lisp_Object trustfile = Fcar (tail);
-          if (STRINGP (trustfile))
-            {
-              GNUTLS_LOG2 (1, max_log_level, "setting the trustfile: ",
-                           SSDATA (trustfile));
-              ret = gnutls_certificate_set_x509_trust_file
-                (x509_cred,
-                 SSDATA (trustfile),
-                 file_format);
-
-              if (ret < GNUTLS_E_SUCCESS)
-                return gnutls_make_error (ret);
-            }
-          else
-            {
-              error ("Sorry, GnuTLS can't use non-string trustfile %s",
-                     SDATA (trustfile));
-            }
-        }
-
-      for (tail = keyfiles; !NILP (tail); tail = Fcdr (tail))
+         if (STRINGP (trustfile))
+           {
+             GNUTLS_LOG2 (1, max_log_level, "setting the trustfile: ",
+                          SSDATA (trustfile));
+             ret = fn_gnutls_certificate_set_x509_trust_file
+               (x509_cred,
+                SSDATA (trustfile),
+                file_format);
+
+             if (ret < GNUTLS_E_SUCCESS)
+               return gnutls_make_error (ret);
+           }
+         else
+           {
+             emacs_gnutls_deinit (proc);
+             error ("Invalid trustfile");
+           }
+       }
+
+      for (tail = crlfiles; !NILP (tail); tail = Fcdr (tail))
+       {
+         Lisp_Object crlfile = Fcar (tail);
+         if (STRINGP (crlfile))
+           {
+             GNUTLS_LOG2 (1, max_log_level, "setting the CRL file: ",
+                          SSDATA (crlfile));
+             ret = fn_gnutls_certificate_set_x509_crl_file
+               (x509_cred, SSDATA (crlfile), file_format);
+
+             if (ret < GNUTLS_E_SUCCESS)
+               return gnutls_make_error (ret);
+           }
+         else
+           {
+             emacs_gnutls_deinit (proc);
+             error ("Invalid CRL file");
+           }
+       }
+
+      for (tail = keylist; !NILP (tail); tail = Fcdr (tail))
        {
-         Lisp_Object keyfile = Fcar (tail);
-          if (STRINGP (keyfile))
-            {
-              GNUTLS_LOG2 (1, max_log_level, "setting the keyfile: ",
-                           SSDATA (keyfile));
-              ret = gnutls_certificate_set_x509_crl_file
-                (x509_cred,
-                 SSDATA (keyfile),
-                 file_format);
-
-              if (ret < GNUTLS_E_SUCCESS)
-                return gnutls_make_error (ret);
-            }
-          else
-            {
-              error ("Sorry, GnuTLS can't use non-string keyfile %s",
-                     SDATA (keyfile));
-            }
-        }
+         Lisp_Object keyfile = Fcar (Fcar (tail));
+         Lisp_Object certfile = Fcar (Fcdr (tail));
+         if (STRINGP (keyfile) && STRINGP (certfile))
+           {
+             GNUTLS_LOG2 (1, max_log_level, "setting the client key file: ",
+                          SSDATA (keyfile));
+             GNUTLS_LOG2 (1, max_log_level, "setting the client cert file: ",
+                          SSDATA (certfile));
+             ret = fn_gnutls_certificate_set_x509_key_file
+               (x509_cred, SSDATA (certfile), SSDATA (keyfile), file_format);
+
+             if (ret < GNUTLS_E_SUCCESS)
+               return gnutls_make_error (ret);
+           }
+         else
+           {
+             emacs_gnutls_deinit (proc);
+             error (STRINGP (keyfile) ? "Invalid client cert file"
+                    : "Invalid client key file");
+           }
+       }
     }
 
   GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_FILES;
+  GNUTLS_LOG (1, max_log_level, "gnutls callbacks");
+  GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_CALLBACKS;
 
-  GNUTLS_LOG (1, max_log_level, "gnutls_init");
-
-  ret = gnutls_init (&state, GNUTLS_CLIENT);
+  /* Call gnutls_init here: */
 
+  GNUTLS_LOG (1, max_log_level, "gnutls_init");
+  ret = fn_gnutls_init (&state, GNUTLS_CLIENT);
+  XPROCESS (proc)->gnutls_state = state;
   if (ret < GNUTLS_E_SUCCESS)
     return gnutls_make_error (ret);
-
-  XPROCESS (proc)->gnutls_state = state;
-
   GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_INIT;
 
   if (STRINGP (priority_string))
     {
       priority_string_ptr = SSDATA (priority_string);
       GNUTLS_LOG2 (1, max_log_level, "got non-default priority string:",
-                   priority_string_ptr);
+                  priority_string_ptr);
     }
   else
     {
       GNUTLS_LOG2 (1, max_log_level, "using default priority string:",
-                   priority_string_ptr);
+                  priority_string_ptr);
     }
 
   GNUTLS_LOG (1, max_log_level, "setting the priority string");
+  ret = fn_gnutls_priority_set_direct (state,
+                                      priority_string_ptr,
+                                      NULL);
+  if (ret < GNUTLS_E_SUCCESS)
+    return gnutls_make_error (ret);
 
-  ret = gnutls_priority_set_direct (state,
-                                   priority_string_ptr,
-                                   NULL);
+  GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_PRIORITY;
+
+  if (INTEGERP (prime_bits))
+    fn_gnutls_dh_set_prime_bits (state, XUINT (prime_bits));
 
+  ret = EQ (type, Qgnutls_x509pki)
+    ? fn_gnutls_credentials_set (state, GNUTLS_CRD_CERTIFICATE, x509_cred)
+    : fn_gnutls_credentials_set (state, GNUTLS_CRD_ANON, anon_cred);
   if (ret < GNUTLS_E_SUCCESS)
     return gnutls_make_error (ret);
 
-  GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_PRIORITY;
+  GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_CRED_SET;
+  ret = emacs_gnutls_handshake (XPROCESS (proc));
+  if (ret < GNUTLS_E_SUCCESS)
+    return gnutls_make_error (ret);
 
-  if (EQ (type, Qgnutls_x509pki))
-    {
-      ret = gnutls_cred_set (state, GNUTLS_CRD_CERTIFICATE, x509_cred);
-    }
-  else if (EQ (type, Qgnutls_anon))
+  /* Now verify the peer, following
+     http://www.gnu.org/software/gnutls/manual/html_node/Verifying-peer_0027s-certificate.html.
+     The peer should present at least one certificate in the chain; do a
+     check of the certificate's hostname with
+     gnutls_x509_crt_check_hostname() against :hostname.  */
+
+  ret = fn_gnutls_certificate_verify_peers2 (state, &peer_verification);
+  if (ret < GNUTLS_E_SUCCESS)
+    return gnutls_make_error (ret);
+
+  if (XINT (loglevel) > 0 && peer_verification & GNUTLS_CERT_INVALID)
+    message ("%s certificate could not be verified.", c_hostname);
+
+  if (peer_verification & GNUTLS_CERT_REVOKED)
+    GNUTLS_LOG2 (1, max_log_level, "certificate was revoked (CRL):",
+                c_hostname);
+
+  if (peer_verification & GNUTLS_CERT_SIGNER_NOT_FOUND)
+    GNUTLS_LOG2 (1, max_log_level, "certificate signer was not found:",
+                c_hostname);
+
+  if (peer_verification & GNUTLS_CERT_SIGNER_NOT_CA)
+    GNUTLS_LOG2 (1, max_log_level, "certificate signer is not a CA:",
+                c_hostname);
+
+  if (peer_verification & GNUTLS_CERT_INSECURE_ALGORITHM)
+    GNUTLS_LOG2 (1, max_log_level,
+                "certificate was signed with an insecure algorithm:",
+                c_hostname);
+
+  if (peer_verification & GNUTLS_CERT_NOT_ACTIVATED)
+    GNUTLS_LOG2 (1, max_log_level, "certificate is not yet activated:",
+                c_hostname);
+
+  if (peer_verification & GNUTLS_CERT_EXPIRED)
+    GNUTLS_LOG2 (1, max_log_level, "certificate has expired:",
+                c_hostname);
+
+  if (peer_verification != 0)
     {
-      ret = gnutls_cred_set (state, GNUTLS_CRD_ANON, anon_cred);
+      if (NILP (verify_hostname_error))
+       GNUTLS_LOG2 (1, max_log_level, "certificate validation failed:",
+                    c_hostname);
+      else
+       {
+         emacs_gnutls_deinit (proc);
+         error ("Certificate validation failed %s, verification code %d",
+                c_hostname, peer_verification);
+       }
     }
-  else
+
+  /* Up to here the process is the same for X.509 certificates and
+     OpenPGP keys.  From now on X.509 certificates are assumed.  This
+     can be easily extended to work with openpgp keys as well.  */
+  if (fn_gnutls_certificate_type_get (state) == GNUTLS_CRT_X509)
     {
-      error ("unknown credential type");
-      ret = GNUTLS_EMACS_ERROR_INVALID_TYPE;
-    }
+      gnutls_x509_crt_t gnutls_verify_cert;
+      const gnutls_datum_t *gnutls_verify_cert_list;
+      unsigned int gnutls_verify_cert_list_size;
 
-  if (ret < GNUTLS_E_SUCCESS)
-    return gnutls_make_error (ret);
+      ret = fn_gnutls_x509_crt_init (&gnutls_verify_cert);
+      if (ret < GNUTLS_E_SUCCESS)
+       return gnutls_make_error (ret);
 
-  XPROCESS (proc)->gnutls_anon_cred = anon_cred;
-  XPROCESS (proc)->gnutls_x509_cred = x509_cred;
-  XPROCESS (proc)->gnutls_cred_type = type;
+      gnutls_verify_cert_list =
+       fn_gnutls_certificate_get_peers (state, &gnutls_verify_cert_list_size);
 
-  GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_CRED_SET;
+      if (gnutls_verify_cert_list == NULL)
+       {
+         fn_gnutls_x509_crt_deinit (gnutls_verify_cert);
+         emacs_gnutls_deinit (proc);
+         error ("No x509 certificate was found\n");
+       }
 
-  emacs_gnutls_handshake (XPROCESS (proc));
+      /* We only check the first certificate in the given chain.  */
+      ret = fn_gnutls_x509_crt_import (gnutls_verify_cert,
+                                      &gnutls_verify_cert_list[0],
+                                      GNUTLS_X509_FMT_DER);
 
-  return gnutls_make_error (GNUTLS_E_SUCCESS);
+      if (ret < GNUTLS_E_SUCCESS)
+       {
+         fn_gnutls_x509_crt_deinit (gnutls_verify_cert);
+         return gnutls_make_error (ret);
+       }
+
+      if (!fn_gnutls_x509_crt_check_hostname (gnutls_verify_cert, c_hostname))
+       {
+         if (NILP (verify_hostname_error))
+           GNUTLS_LOG2 (1, max_log_level, "x509 certificate does not match:",
+                        c_hostname);
+         else
+           {
+             fn_gnutls_x509_crt_deinit (gnutls_verify_cert);
+             emacs_gnutls_deinit (proc);
+             error ("The x509 certificate does not match \"%s\"", c_hostname);
+           }
+       }
+      fn_gnutls_x509_crt_deinit (gnutls_verify_cert);
+    }
+
+  return gnutls_make_error (ret);
 }
 
 DEFUN ("gnutls-bye", Fgnutls_bye,
@@ -572,8 +1065,8 @@ This function may also return `gnutls-e-again', or
 
   state = XPROCESS (proc)->gnutls_state;
 
-  ret = gnutls_bye (state,
-                    NILP (cont) ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR);
+  ret = fn_gnutls_bye (state,
+                      NILP (cont) ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR);
 
   return gnutls_make_error (ret);
 }
@@ -581,52 +1074,39 @@ This function may also return `gnutls-e-again', or
 void
 syms_of_gnutls (void)
 {
-  global_initialized = 0;
-
-  Qgnutls_code = intern_c_string ("gnutls-code");
-  staticpro (&Qgnutls_code);
-
-  Qgnutls_anon = intern_c_string ("gnutls-anon");
-  staticpro (&Qgnutls_anon);
-
-  Qgnutls_x509pki = intern_c_string ("gnutls-x509pki");
-  staticpro (&Qgnutls_x509pki);
-
-  Qgnutls_bootprop_priority = intern_c_string (":priority");
-  staticpro (&Qgnutls_bootprop_priority);
-
-  Qgnutls_bootprop_trustfiles = intern_c_string (":trustfiles");
-  staticpro (&Qgnutls_bootprop_trustfiles);
-
-  Qgnutls_bootprop_keyfiles = intern_c_string (":keyfiles");
-  staticpro (&Qgnutls_bootprop_keyfiles);
-
-  Qgnutls_bootprop_callbacks = intern_c_string (":callbacks");
-  staticpro (&Qgnutls_bootprop_callbacks);
-
-  Qgnutls_bootprop_loglevel = intern_c_string (":loglevel");
-  staticpro (&Qgnutls_bootprop_loglevel);
-
-  Qgnutls_e_interrupted = intern_c_string ("gnutls-e-interrupted");
-  staticpro (&Qgnutls_e_interrupted);
+  gnutls_global_initialized = 0;
+
+  DEFSYM (Qgnutls_dll, "gnutls");
+  DEFSYM (Qgnutls_code, "gnutls-code");
+  DEFSYM (Qgnutls_anon, "gnutls-anon");
+  DEFSYM (Qgnutls_x509pki, "gnutls-x509pki");
+  DEFSYM (QCgnutls_bootprop_hostname, ":hostname");
+  DEFSYM (QCgnutls_bootprop_priority, ":priority");
+  DEFSYM (QCgnutls_bootprop_trustfiles, ":trustfiles");
+  DEFSYM (QCgnutls_bootprop_keylist, ":keylist");
+  DEFSYM (QCgnutls_bootprop_crlfiles, ":crlfiles");
+  DEFSYM (QCgnutls_bootprop_callbacks, ":callbacks");
+  DEFSYM (QCgnutls_bootprop_callbacks_verify, "verify");
+  DEFSYM (QCgnutls_bootprop_min_prime_bits, ":min-prime-bits");
+  DEFSYM (QCgnutls_bootprop_loglevel, ":loglevel");
+  DEFSYM (QCgnutls_bootprop_verify_flags, ":verify-flags");
+  DEFSYM (QCgnutls_bootprop_verify_hostname_error, ":verify-hostname-error");
+
+  DEFSYM (Qgnutls_e_interrupted, "gnutls-e-interrupted");
   Fput (Qgnutls_e_interrupted, Qgnutls_code,
-        make_number (GNUTLS_E_INTERRUPTED));
+       make_number (GNUTLS_E_INTERRUPTED));
 
-  Qgnutls_e_again = intern_c_string ("gnutls-e-again");
-  staticpro (&Qgnutls_e_again);
+  DEFSYM (Qgnutls_e_again, "gnutls-e-again");
   Fput (Qgnutls_e_again, Qgnutls_code,
-        make_number (GNUTLS_E_AGAIN));
+       make_number (GNUTLS_E_AGAIN));
 
-  Qgnutls_e_invalid_session = intern_c_string ("gnutls-e-invalid-session");
-  staticpro (&Qgnutls_e_invalid_session);
+  DEFSYM (Qgnutls_e_invalid_session, "gnutls-e-invalid-session");
   Fput (Qgnutls_e_invalid_session, Qgnutls_code,
-        make_number (GNUTLS_E_INVALID_SESSION));
+       make_number (GNUTLS_E_INVALID_SESSION));
 
-  Qgnutls_e_not_ready_for_handshake =
-    intern_c_string ("gnutls-e-not-ready-for-handshake");
-  staticpro (&Qgnutls_e_not_ready_for_handshake);
+  DEFSYM (Qgnutls_e_not_ready_for_handshake, "gnutls-e-not-ready-for-handshake");
   Fput (Qgnutls_e_not_ready_for_handshake, Qgnutls_code,
-        make_number (GNUTLS_E_APPLICATION_ERROR_MIN));
+       make_number (GNUTLS_E_APPLICATION_ERROR_MIN));
 
   defsubr (&Sgnutls_get_initstage);
   defsubr (&Sgnutls_errorp);
@@ -635,5 +1115,11 @@ syms_of_gnutls (void)
   defsubr (&Sgnutls_boot);
   defsubr (&Sgnutls_deinit);
   defsubr (&Sgnutls_bye);
+  defsubr (&Sgnutls_available_p);
+
+  DEFVAR_INT ("gnutls-log-level", global_gnutls_log_level,
+             doc: /* Logging level used by the GnuTLS functions.  */);
+  global_gnutls_log_level = 0;
 }
-#endif
+
+#endif /* HAVE_GNUTLS */