Bump copyright

[privoxy.git] / gateway.c

diff --git a/gateway.c b/gateway.c
index b341ae9..fd7d115 100644 (file)
--- a/gateway.c
+++ b/gateway.c
@@ -6,7 +6,7 @@
  *                using a "forwarder" (i.e. HTTP proxy and/or a SOCKS4
  *                or SOCKS5 proxy).
  *
- * Copyright   :  Written by and Copyright (C) 2001-2020 the
+ * Copyright   :  Written by and Copyright (C) 2001-2021 the
  *                Privoxy team. https://www.privoxy.org/
  *
  *                Based on the Internet Junkbuster originally written
@@ -1029,6 +1029,53 @@ static const char *translate_socks5_error(int socks_error)
 }
 
 
+/*********************************************************************
+ *
+ * Function    :  convert_ipv4_address_to_bytes
+ *
+ * Description :  Converts an IPv4 address from string to bytes.
+ *
+ * Parameters  :
+ *          1  :  address = The IPv4 address string to convert.
+ *          2  :  buf = The buffer to write the bytes to.
+ *                      Must be at least four bytes long.
+ *
+ * Returns     :  JB_ERR_OK on success, JB_ERR_PARSE otherwise.
+ *
+ *********************************************************************/
+static jb_err convert_ipv4_address_to_bytes(const char *address, char *buf)
+{
+   int i;
+   const char *p = address;
+
+   for (i = 0; i < 4; i++)
+   {
+      unsigned byte;
+      if (1 != sscanf(p, "%u", &byte))
+      {
+         return JB_ERR_PARSE;
+      }
+      if (byte > 255)
+      {
+         return JB_ERR_PARSE;
+      }
+      buf[i] = (char)byte;
+      if (i < 3)
+      {
+         p = strstr(p, ".");
+         if (p == NULL)
+         {
+            return JB_ERR_PARSE;
+         }
+         p++;
+      }
+   }
+
+   return JB_ERR_OK;
+
+}
+
+
 /*********************************************************************
  *
  * Function    :  socks5_connect
@@ -1055,10 +1102,11 @@ static jb_socket socks5_connect(const struct forward_spec *fwd,
 {
 #define SIZE_SOCKS5_REPLY_IPV4 10
 #define SIZE_SOCKS5_REPLY_IPV6 22
+#define SIZE_SOCKS5_REPLY_DOMAIN 300
 #define SOCKS5_REPLY_DIFFERENCE (SIZE_SOCKS5_REPLY_IPV6 - SIZE_SOCKS5_REPLY_IPV4)
    int err = 0;
    char cbuf[300];
-   char sbuf[SIZE_SOCKS5_REPLY_IPV6];
+   char sbuf[SIZE_SOCKS5_REPLY_DOMAIN];
    size_t client_pos = 0;
    int server_size = 0;
    size_t hostlen = 0;
@@ -1180,11 +1228,20 @@ static jb_socket socks5_connect(const struct forward_spec *fwd,
 
    if (!err && (sbuf[1] == '\x02'))
    {
-      /* check cbuf overflow */
-      size_t auth_len = strlen(fwd->auth_username) + strlen(fwd->auth_password) + 3;
-      if (auth_len > sizeof(cbuf))
+      if (fwd->auth_username && fwd->auth_password)
+      {
+         /* check cbuf overflow */
+         size_t auth_len = strlen(fwd->auth_username) + strlen(fwd->auth_password) + 3;
+         if (auth_len > sizeof(cbuf))
+         {
+            errstr = "SOCKS5 username and/or password too long";
+            err = 1;
+         }
+      }
+      else
       {
-         errstr = "SOCKS5 username and/or password too long";
+         errstr = "SOCKS5 server requested authentication while "
+            "no credentials are configured";
          err = 1;
       }
 
@@ -1242,12 +1299,32 @@ static jb_socket socks5_connect(const struct forward_spec *fwd,
    cbuf[client_pos++] = '\x05'; /* Version */
    cbuf[client_pos++] = '\x01'; /* TCP connect */
    cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
-   cbuf[client_pos++] = '\x03'; /* Address is domain name */
-   cbuf[client_pos++] = (char)(hostlen & 0xffu);
-   assert(sizeof(cbuf) - client_pos > (size_t)255);
-   /* Using strncpy because we really want the nul byte padding. */
-   strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
-   client_pos += (hostlen & 0xffu);
+   if (host_is_ip_address(target_host) && NULL == strstr(target_host, ":"))
+   {
+      cbuf[client_pos++] = '\x01'; /* Address is IPv4 address. */
+      if (JB_ERR_OK != convert_ipv4_address_to_bytes(target_host, &cbuf[client_pos]))
+      {
+         errstr = "SOCKS5 error. Failed to convert target address to IP address";
+         csp->error_message = strdup(errstr);
+         log_error(LOG_LEVEL_CONNECT, "%s", errstr);
+         close_socket(sfd);
+         errno = EINVAL;
+         return(JB_INVALID_SOCKET);
+      }
+      client_pos += 4;
+   }
+   else
+   {
+      /*
+       * XXX: This branch is currently also used for IPv6 addresses
+       */
+      cbuf[client_pos++] = '\x03'; /* Address is domain name. */
+      cbuf[client_pos++] = (char)(hostlen & 0xffu);
+      assert(sizeof(cbuf) - client_pos > (size_t)255);
+      /* Using strncpy because we really want the nul byte padding. */
+      strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos - 1);
+      client_pos += (hostlen & 0xffu);
+   }
    cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
    cbuf[client_pos++] = (char)((target_port     ) & 0xff);
 
@@ -1349,9 +1426,32 @@ static jb_socket socks5_connect(const struct forward_spec *fwd,
                errstr = "SOCKS5 negotiation read failed (IPv6 address)";
             }
          }
+         else if (sbuf[3] == '\x03')
+         {
+            /*
+             * The address field contains a domain name
+             * which means we didn't get the whole reply
+             * yet. Read and discard the rest of it to make
+             * sure it isn't treated as HTTP data later on.
+             */
+            unsigned domain_length = (unsigned)sbuf[4];
+            int bytes_left_to_read = 5 + (int)domain_length + 2 - SIZE_SOCKS5_REPLY_IPV4;
+            if (bytes_left_to_read <= 0 || sizeof(sbuf) < bytes_left_to_read)
+            {
+               errstr = "SOCKS5 negotiation read failed (Invalid domain length)";
+            }
+            else
+            {
+               server_size = read_socket(sfd, sbuf, bytes_left_to_read);
+               if (server_size != bytes_left_to_read)
+               {
+                  errstr = "SOCKS5 negotiation read failed (Domain name)";
+               }
+            }
+         }
          else if (sbuf[3] != '\x01')
          {
-             errstr = "SOCKS5 reply contains unsupported address type";
+            errstr = "SOCKS5 reply contains unsupported address type";
          }
          if (errstr == NULL)
          {