dirmngr: Support Tor hidden services.

* dirmngr/dns-stuff.c (is_onion_address): New.
* dirmngr/ks-engine-hkp.c (hostinfo_s): Add field "onion".
(map_host): Special case onion addresses.
(ks_hkp_print_hosttable): Print an 'O' for an onion address.
* dirmngr/http.c (connect_server): Special case onion addresses.
--

Note that this requires the latest libassuan from git.  Onion addresses
are always support regardless of the --use-tor flag.

Signed-off-by: Werner Koch <wk@gnupg.org>

dirmngr/dns-stuff.c

@@ -403,6 +403,20 @@ is_ip_address (const char *name)
 }
 
 
+/* Return true if NAME is an onion address.  */
+int
+is_onion_address (const char *name)
+{
+  size_t len;
+
+  len = name? strlen (name) : 0;
+  if (len < 8 || strcmp (name + len - 6, ".onion"))
+    return 0;
+  /* Note that we require at least 2 characters before the suffix.  */
+  return 1;  /* Yes.  */
+}
+
+
 #ifdef USE_ADNS
 /* Init ADNS and store the new state at R_STATE.  Returns 0 on
    success; prints an error message and returns an error code on

dirmngr/dns-stuff.h

@@ -110,6 +110,9 @@ gpg_error_t resolve_dns_addr (const struct sockaddr *addr, int addrlen,
 /* Return true if NAME is a numerical IP address.  */
 int is_ip_address (const char *name);
 
+/* Return true if NAME is an onion address.  */
+int is_onion_address (const char *name);
+
 /* Get the canonical name for NAME.  */
 gpg_error_t get_dns_cname (const char *name, char **r_cname);
 

dirmngr/http.c

@@ -2212,6 +2212,32 @@ connect_server (const char *server, unsigned short port,
   init_sockets ();
 #endif /*Windows*/
 
+  /* Onion addresses require special treatment.  */
+  if (is_onion_address (server))
+    {
+#ifdef ASSUAN_SOCK_TOR
+
+      my_unprotect ();
+      sock = assuan_sock_connect_byname (server, port, 0, NULL,
+                                         ASSUAN_SOCK_TOR);
+      my_protect ();
+
+      if (sock == ASSUAN_INVALID_FD)
+        {
+          if (errno == EHOSTUNREACH)
+            *r_host_not_found = 1;
+          log_error ("can't connect to '%s': %s\n", server, strerror (errno));
+        }
+      return sock;
+
+#else /*!ASSUAN_SOCK_TOR*/
+
+      gpg_err_set_errno (ENETUNREACH);
+      return -1; /* Out of core.  */
+
+#endif /*!HASSUAN_SOCK_TOR*/
+    }
+
 #ifdef USE_DNS_SRV
   /* Do the SRV thing */
   if (srvtag)

dirmngr/ks-engine-hkp.c

@@ -80,6 +80,7 @@ struct hostinfo_s
   int poolidx;       /* Index into POOL with the used host.  -1 if not set.  */
   unsigned int v4:1; /* Host supports AF_INET.  */
   unsigned int v6:1; /* Host supports AF_INET6.  */
+  unsigned int onion:1;/* NAME is an onion (Tor HS) address.  */
   unsigned int dead:1; /* Host is currently unresponsive.  */
   time_t died_at;    /* The time the host was marked dead.  If this is
                         0 the host has been manually marked dead.  */
@@ -124,6 +125,7 @@ create_new_hostinfo (const char *name)
   hi->lastfail = (time_t)(-1);
   hi->v4 = 0;
   hi->v6 = 0;
+  hi->onion = 0;
   hi->dead = 0;
   hi->died_at = 0;
   hi->cname = NULL;
@@ -267,7 +269,15 @@ map_host (ctrl_t ctrl, const char *name, int force_reselect,
 
   /* See whether the host is in our table.  */
   idx = find_hostinfo (name);
+  if (idx == -1 && is_onion_address (name))
+    {
+      idx = create_new_hostinfo (name);
       if (idx == -1)
+        return gpg_error_from_syserror ();
+      hi = hosttable[idx];
+      hi->onion = 1;
+    }
+  else if (idx == -1)
     {
       /* We never saw this host.  Allocate a new entry.  */
       dns_addrinfo_t aibuf, ai;
@@ -512,6 +522,11 @@ map_host (ctrl_t ctrl, const char *name, int force_reselect,
         *r_httpflags |= HTTP_FLAG_IGNORE_IPv4;
       if (!hi->v6)
         *r_httpflags |= HTTP_FLAG_IGNORE_IPv6;
+
+      /* Note that we do not set the HTTP_FLAG_FORCE_TOR for onion
+         addresses because the http module detects this itself.  This
+         also allows us to use an onion address without Tor mode being
+         enabled.  */
     }
 
   *r_host = xtrystrdup (hi->name);
@@ -683,7 +698,9 @@ ks_hkp_print_hosttable (ctrl_t ctrl)
         else
           diedstr = died = NULL;
         err = ks_printf_help (ctrl, "%3d %s %s %s %s%s%s%s%s%s%s%s\n",
-                              idx, hi->v6? "6":" ", hi->v4? "4":" ",
+                              idx,
+                              hi->onion? "O" : hi->v6? "6":" ",
+                              hi->v4? "4":" ",
                               hi->dead? "d":" ",
                               hi->name,
                               hi->v6addr? " v6=":"",