- Markus Moeller introduced two new options to libcurl:

  CURLOPT_SOCKS5_GSSAPI_SERVICE and CURLOPT_SOCKS5_GSSAPI_NEC to allow libcurl
  to do GSS-style authentication with SOCKS5 proxies. The curl tool got the
  options called --socks5-gssapi-service and --socks5-gssapi-nec to enable
  these.

9 files changed, 1322 insertions, 23 deletions

diff --git a/lib/Makefile.inc b/lib/Makefile.inc
index e3489904b..85fc24e99 100644
--- a/lib/Makefile.inc
+++ b/lib/Makefile.inc
@@ -9,7 +9,8 @@ CSOURCES = file.c timeval.c base64.c hostip.c progress.c formdata.c	\
   http_negotiate.c http_ntlm.c inet_pton.c strtoofft.c strerror.c	\
   hostares.c hostasyn.c hostip4.c hostip6.c hostsyn.c hostthre.c	\
   inet_ntop.c parsedate.c select.c gtls.c sslgen.c tftp.c splay.c	\
-  strdup.c socks.c ssh.c nss.c qssl.c rawstr.c curl_addrinfo.c
+  strdup.c socks.c ssh.c nss.c qssl.c rawstr.c curl_addrinfo.c          \
+  socks_gssapi.c socks_sspi.c
 
 HHEADERS = arpa_telnet.h netrc.h file.h timeval.h qssl.h hostip.h	\
   progress.h formdata.h cookie.h http.h sendf.h ftp.h url.h dict.h	\
diff --git a/lib/Makefile.vc6 b/lib/Makefile.vc6
index 9fd540b5a..d9d627711 100644
--- a/lib/Makefile.vc6
+++ b/lib/Makefile.vc6
@@ -101,7 +101,7 @@ LFLAGS     = /nologo /machine:$(MACHINE)
 SSLLIBS    = libeay32.lib ssleay32.lib

 ZLIBLIBSDLL= zdll.lib

 ZLIBLIBS   = zlib.lib

-WINLIBS    = wsock32.lib wldap32.lib

+WINLIBS    = wsock32.lib wldap32.lib secur32.lib

 CFLAGS     = $(CFLAGS)

 

 CFGSET     = FALSE

@@ -489,6 +489,7 @@ X_OBJS= \
 	$(DIROBJ)\sendf.obj \

 	$(DIROBJ)\share.obj \

 	$(DIROBJ)\socks.obj \

+	$(DIROBJ)\socks_sspi.obj \

 	$(DIROBJ)\speedcheck.obj \

 	$(DIROBJ)\splay.obj \

 	$(DIROBJ)\ssh.obj \

diff --git a/lib/socks.c b/lib/socks.c
index 693573209..9fc5b7948 100644
--- a/lib/socks.c
+++ b/lib/socks.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2008, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2009, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -60,14 +60,14 @@
  * This is STUPID BLOCKING behaviour which we frown upon, but right now this
  * is what we have...
  */
-static int blockread_all(struct connectdata *conn, /* connection data */
-                         curl_socket_t sockfd,     /* read from this socket */
-                         char *buf,                /* store read data here */
-                         ssize_t buffersize,       /* max amount to read */
-                         ssize_t *n,               /* amount bytes read */
-                         long conn_timeout)        /* timeout for data wait
-                                                      relative to
-                                                      conn->created */
+int Curl_blockread_all(struct connectdata *conn, /* connection data */
+                       curl_socket_t sockfd,     /* read from this socket */
+                       char *buf,                /* store read data here */
+                       ssize_t buffersize,       /* max amount to read */
+                       ssize_t *n,               /* amount bytes read */
+                       long conn_timeout)        /* timeout for data wait
+                                                    relative to
+                                                    conn->created */
 {
   ssize_t nread;
   ssize_t allread = 0;
@@ -264,7 +264,7 @@ CURLcode Curl_SOCKS4(const char *proxy_name,
     packetsize = 8; /* receive data size */
 
     /* Receive response */
-    result = blockread_all(conn, sock, (char *)socksreq, packetsize,
+    result = Curl_blockread_all(conn, sock, (char *)socksreq, packetsize,
                            &actualread, timeout);
     if((result != CURLE_OK) || (actualread != packetsize)) {
       failf(data, "Failed to receive SOCKS4 connect request ack.");
@@ -429,9 +429,16 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
   }
 
   socksreq[0] = 5; /* version */
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  socksreq[1] = (char)(proxy_name ? 3 : 2); /* number of methods (below) */
+  socksreq[2] = 0; /* no authentication */
+  socksreq[3] = 1; /* gssapi */
+  socksreq[4] = 2; /* username/password */
+#else
   socksreq[1] = (char)(proxy_name ? 2 : 1); /* number of methods (below) */
   socksreq[2] = 0; /* no authentication */
   socksreq[3] = 2; /* username/password */
+#endif
 
   Curl_nonblock(sock, FALSE);
 
@@ -462,7 +469,8 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
 
   Curl_nonblock(sock, FALSE);
 
-  result=blockread_all(conn, sock, (char *)socksreq, 2, &actualread, timeout);
+  result=Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread,
+                            timeout);
   if((result != CURLE_OK) || (actualread != 2)) {
     failf(data, "Unable to receive initial SOCKS5 response.");
     return CURLE_COULDNT_CONNECT;
@@ -476,6 +484,15 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
     /* Nothing to do, no authentication needed */
     ;
   }
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  else if(socksreq[1] == 1) {
+    code = Curl_SOCKS5_gssapi_negotiate(sockindex, conn);
+    if(code != CURLE_OK) {
+      failf(data, "Unable to negotiate SOCKS5 gssapi context.");
+      return CURLE_COULDNT_CONNECT;
+    }
+  }
+#endif
   else if(socksreq[1] == 2) {
     /* Needs user name and password */
     size_t userlen, pwlen;
@@ -511,7 +528,7 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
       return CURLE_COULDNT_CONNECT;
     }
 
-    result=blockread_all(conn, sock, (char *)socksreq, 2, &actualread,
+    result=Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread,
                          timeout);
     if((result != CURLE_OK) || (actualread != 2)) {
       failf(data, "Unable to receive SOCKS5 sub-negotiation response.");
@@ -529,12 +546,16 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
   }
   else {
     /* error */
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+    if(socksreq[1] == 255) {
+#else
     if(socksreq[1] == 1) {
       failf(data,
             "SOCKS5 GSSAPI per-message authentication is not supported.");
       return CURLE_COULDNT_CONNECT;
     }
     else if(socksreq[1] == 255) {
+#endif
       if(!proxy_name || !*proxy_name) {
         failf(data,
               "No authentication method was acceptable. (It is quite likely"
@@ -616,6 +637,11 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
     *((unsigned short*)&socksreq[8]) = htons((unsigned short)remote_port);
   }
 
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  if(conn->socks5_gssapi_enctype) {
+    failf(data, "SOCKS5 gssapi protection not yet implemented.");
+  } else
+#endif
   code = Curl_write_plain(conn, sock, (char *)socksreq, packetsize, &written);
   if((code != CURLE_OK) || (written != packetsize)) {
     failf(data, "Failed to send SOCKS5 connect request.");
@@ -624,7 +650,12 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
 
   packetsize = 10; /* minimum packet size is 10 */
 
-  result = blockread_all(conn, sock, (char *)socksreq, packetsize,
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  if(conn->socks5_gssapi_enctype) {
+    failf(data, "SOCKS5 gssapi protection not yet implemented.");
+  } else
+#endif
+    result = Curl_blockread_all(conn, sock, (char *)socksreq, packetsize,
                            &actualread, timeout);
   if((result != CURLE_OK) || (actualread != packetsize)) {
     failf(data, "Failed to receive SOCKS5 connect request ack.");
@@ -674,15 +705,22 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
   }
 
   /* At this point we already read first 10 bytes */
-  if(packetsize > 10) {
-    packetsize -= 10;
-    result = blockread_all(conn, sock, (char *)&socksreq[10], packetsize,
-                           &actualread, timeout);
-    if((result != CURLE_OK) || (actualread != packetsize)) {
-      failf(data, "Failed to receive SOCKS5 connect request ack.");
-      return CURLE_COULDNT_CONNECT;
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  if(!conn->socks5_gssapi_enctype) {
+    /* decrypt_gssapi_blockread already read the whole packet */
+#endif
+    if(packetsize > 10) {
+      packetsize -= 10;
+      result = Curl_blockread_all(conn, sock, (char *)&socksreq[10],
+                                  packetsize, &actualread, timeout);
+      if((result != CURLE_OK) || (actualread != packetsize)) {
+        failf(data, "Failed to receive SOCKS5 connect request ack.");
+        return CURLE_COULDNT_CONNECT;
+      }
     }
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
   }
+#endif
 
   Curl_nonblock(sock, TRUE);
   return CURLE_OK; /* Proxy was successful! */
diff --git a/lib/socks.h b/lib/socks.h
index 756ecc3db..9f4c6f09a 100644
--- a/lib/socks.h
+++ b/lib/socks.h
@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2008, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2009, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -24,6 +24,20 @@
  ***************************************************************************/
 
 /*
+ * Helper read-from-socket functions. Does the same as Curl_read() but it
+ * blocks until all bytes amount of buffersize will be read. No more, no less.
+ *
+ * This is STUPID BLOCKING behaviour which we frown upon, but right now this
+ * is what we have...
+ */
+int Curl_blockread_all(struct connectdata *conn,
+                       curl_socket_t sockfd,
+                       char *buf,
+                       ssize_t buffersize,
+                       ssize_t *n,
+                       long conn_timeout);
+
+/*
  * This function logs in to a SOCKS4(a) proxy and sends the specifics to the
  * final destination server.
  */
@@ -45,4 +59,12 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
                      int sockindex,
                      struct connectdata *conn);
 
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+/*
+ * This function handles the sockss5 gssapie negotiation and initialisation
+ */
+CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
+                                      struct connectdata *conn);
 #endif
+
+#endif  /* __SOCKS_H */
diff --git a/lib/socks_gssapi.c b/lib/socks_gssapi.c
new file mode 100644
index 000000000..cd9e1a4d3
--- /dev/null
+++ b/lib/socks_gssapi.c
@@ -0,0 +1,547 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2009, Markus Moeller, <markus_moeller@compuserve.com>
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id$
+ ***************************************************************************/
+
+#include "setup.h"
+
+#ifdef HAVE_GSSAPI
+#ifdef HAVE_OLD_GSSMIT
+#define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name
+#endif
+#ifndef gss_nt_service_name
+#define gss_nt_service_name GSS_C_NT_HOSTBASED_SERVICE
+#endif
+#include <string.h>
+
+#ifdef NEED_MALLOC_H
+#include <malloc.h>
+#endif
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+
+#include "urldata.h"
+#include "sendf.h"
+#include "connect.h"
+#include "timeval.h"
+#include "socks.h"
+
+static gss_ctx_id_t     gss_context = GSS_C_NO_CONTEXT;
+
+#define _MPRINTF_REPLACE /* use our functions only */
+#include <curl/mprintf.h>
+
+/* The last #include file should be: */
+#include "memdebug.h"
+
+/*
+ * Helper gssapi error functions.
+ */
+static int check_gss_err(struct SessionHandle *data,
+                         OM_uint32 major_status,
+                         OM_uint32 minor_status,
+                         const char* function)
+{
+  if(GSS_ERROR(major_status)) {
+    OM_uint32 maj_stat,min_stat;
+    OM_uint32 msg_ctx = 0;
+    gss_buffer_desc status_string;
+    char buf[1024];
+    size_t len;
+
+    len = 0;
+    msg_ctx = 0;
+    while(!msg_ctx) {
+      /* convert major status code (GSS-API error) to text */
+      maj_stat = gss_display_status(&min_stat, major_status,
+                                    GSS_C_GSS_CODE,
+                                    GSS_C_NULL_OID,
+                                    &msg_ctx, &status_string);
+      if(maj_stat == GSS_S_COMPLETE) {
+        if(sizeof(buf) > len + status_string.length + 1) {
+          strcpy(buf+len, (char*) status_string.value);
+          len += status_string.length;
+        }
+        gss_release_buffer(&min_stat, &status_string);
+        break;
+      }
+      gss_release_buffer(&min_stat, &status_string);
+    }
+    if(sizeof(buf) > len + 3) {
+      strcpy(buf+len, ".\n");
+      len += 2;
+    }
+    msg_ctx = 0;
+    while(!msg_ctx) {
+      /* convert minor status code (underlying routine error) to text */
+      maj_stat = gss_display_status(&min_stat, minor_status,
+                                    GSS_C_MECH_CODE,
+                                    GSS_C_NULL_OID,
+                                    &msg_ctx, &status_string);
+      if(maj_stat == GSS_S_COMPLETE) {
+        if(sizeof(buf) > len + status_string.length) {
+          strcpy(buf+len, (char*) status_string.value);
+          len += status_string.length;
+        }
+        gss_release_buffer(&min_stat, &status_string);
+        break;
+      }
+      gss_release_buffer(&min_stat, &status_string);
+    }
+    failf(data, "GSSAPI error: %s failed:\n%s\n", function, buf);
+    return(1);
+  }
+
+  return(0);
+}
+
+CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
+                                      struct connectdata *conn)
+{
+  struct SessionHandle *data = conn->data;
+  curl_socket_t sock = conn->sock[sockindex];
+  CURLcode code;
+  ssize_t actualread;
+  ssize_t written;
+  int result;
+  long timeout;
+  OM_uint32 gss_major_status, gss_minor_status, gss_status;
+  OM_uint32 gss_ret_flags;
+  int gss_conf_state, gss_enc;
+  gss_buffer_desc  service = GSS_C_EMPTY_BUFFER;
+  gss_buffer_desc  gss_send_token = GSS_C_EMPTY_BUFFER;
+  gss_buffer_desc  gss_recv_token = GSS_C_EMPTY_BUFFER;
+  gss_buffer_desc  gss_w_token = GSS_C_EMPTY_BUFFER;
+  gss_buffer_desc* gss_token = GSS_C_NO_BUFFER;
+  gss_name_t       server = GSS_C_NO_NAME;
+  gss_name_t       gss_client_name = GSS_C_NO_NAME;
+  u_short          us_length;
+  char             *user=NULL;
+  unsigned char socksreq[4]; /* room for gssapi exchange header only */
+  char *serviceptr = data->set.str[STRING_SOCKS5_GSSAPI_SERVICE];
+
+  /* get timeout */
+  timeout = Curl_timeleft(conn, NULL, TRUE);
+
+  /*   GSSAPI request looks like
+   * +----+------+-----+----------------+
+   * |VER | MTYP | LEN |     TOKEN      |
+   * +----+------+----------------------+
+   * | 1  |  1   |  2  | up to 2^16 - 1 |
+   * +----+------+-----+----------------+
+   */
+
+  /* prepare service name */
+  if (strchr(serviceptr,'/')) {
+    service.value = malloc(strlen(serviceptr));
+    if(!service.value)
+      return CURLE_OUT_OF_MEMORY;
+    service.length = strlen(serviceptr);
+    memcpy(service.value, serviceptr, service.length);
+
+    gss_major_status = gss_import_name(&gss_minor_status, &service,
+                                       (gss_OID) GSS_C_NULL_OID, &server);
+  }
+  else {
+    service.value = malloc(strlen(serviceptr) +strlen(conn->proxy.name)+2);
+    if(!service.value)
+      return CURLE_OUT_OF_MEMORY;
+    service.length = strlen(serviceptr) +strlen(conn->proxy.name)+1;
+    snprintf(service.value, service.length+1, "%s@%s",
+             serviceptr, conn->proxy.name);
+
+    gss_major_status = gss_import_name(&gss_minor_status, &service,
+                                       gss_nt_service_name, &server);
+  }
+
+  gss_release_buffer(&gss_status, &service); /* clear allocated memory */
+
+  if(check_gss_err(data,gss_major_status,
+                   gss_minor_status,"gss_import_name()")) {
+    failf(data, "Failed to create service name.");
+    gss_release_name(&gss_status, &server);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  /* As long as we need to keep sending some context info, and there's no  */
+  /* errors, keep sending it...                                            */
+  for(;;) {
+    gss_major_status = gss_init_sec_context(&gss_minor_status,
+                                            GSS_C_NO_CREDENTIAL,
+                                            &gss_context, server,
+                                            GSS_C_NULL_OID,
+                                            GSS_C_MUTUAL_FLAG |
+                                            GSS_C_REPLAY_FLAG,
+                                            0,
+                                            NULL,
+                                            gss_token,
+                                            NULL,
+                                            &gss_send_token,
+                                            &gss_ret_flags,
+                                            NULL);
+
+    if(gss_token != GSS_C_NO_BUFFER)
+      gss_release_buffer(&gss_status, &gss_recv_token);
+    if(check_gss_err(data,gss_major_status,
+                     gss_minor_status,"gss_init_sec_context")) {
+      gss_release_name(&gss_status, &server);
+      gss_release_buffer(&gss_status, &gss_recv_token);
+      gss_release_buffer(&gss_status, &gss_send_token);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      failf(data, "Failed to initial GSSAPI token.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    if(gss_send_token.length != 0) {
+      socksreq[0] = 1;    /* gssapi subnegotiation version */
+      socksreq[1] = 1;    /* authentication message type */
+      us_length = htons((short)gss_send_token.length);
+      memcpy(socksreq+2,&us_length,sizeof(short));
+
+      code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
+      if((code != CURLE_OK) || (4 != written)) {
+        failf(data, "Failed to send GSSAPI authentication request.");
+        gss_release_name(&gss_status, &server);
+        gss_release_buffer(&gss_status, &gss_recv_token);
+        gss_release_buffer(&gss_status, &gss_send_token);
+        gss_delete_sec_context(&gss_status, &gss_context, NULL);
+        return CURLE_COULDNT_CONNECT;
+      }
+
+      code = Curl_write_plain(conn, sock, (char *)gss_send_token.value,
+                              gss_send_token.length, &written);
+
+      if((code != CURLE_OK) || ((ssize_t)gss_send_token.length != written)) {
+        failf(data, "Failed to send GSSAPI authentication token.");
+        gss_release_name(&gss_status, &server);
+        gss_release_buffer(&gss_status, &gss_recv_token);
+        gss_release_buffer(&gss_status, &gss_send_token);
+        gss_delete_sec_context(&gss_status, &gss_context, NULL);
+        return CURLE_COULDNT_CONNECT;
+      }
+
+    }
+
+    gss_release_buffer(&gss_status, &gss_send_token);
+    gss_release_buffer(&gss_status, &gss_recv_token);
+    if(gss_major_status != GSS_S_CONTINUE_NEEDED) break;
+
+    /* analyse response */
+
+    /*   GSSAPI response looks like
+     * +----+------+-----+----------------+
+     * |VER | MTYP | LEN |     TOKEN      |
+     * +----+------+----------------------+
+     * | 1  |  1   |  2  | up to 2^16 - 1 |
+     * +----+------+-----+----------------+
+     */
+
+    result=Curl_blockread_all(conn, sock, (char *)socksreq, 4,
+                              &actualread, timeout);
+    if(result != CURLE_OK || actualread != 4) {
+      failf(data, "Failed to receive GSSAPI authentication response.");
+      gss_release_name(&gss_status, &server);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    /* ignore the first (VER) byte */
+    if(socksreq[1] == 255) { /* status / message type */
+      failf(data, "User was rejected by the SOCKS5 server (%d %d).",
+            socksreq[0], socksreq[1]);
+      gss_release_name(&gss_status, &server);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    if(socksreq[1] != 1) { /* status / messgae type */
+      failf(data, "Invalid GSSAPI authentication response type (%d %d).",
+            socksreq[0], socksreq[1]);
+      gss_release_name(&gss_status, &server);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    memcpy(&us_length, socksreq+2, sizeof(short));
+    us_length = ntohs(us_length);
+
+    gss_recv_token.length=us_length;
+    gss_recv_token.value=malloc(us_length);
+    if(!gss_recv_token.value) {
+      failf(data,
+            "Could not allocate memory for GSSAPI authentication "
+            "response token.");
+      gss_release_name(&gss_status, &server);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_OUT_OF_MEMORY;
+    }
+
+    result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value,
+                              gss_recv_token.length,
+                              &actualread, timeout);
+
+    if(result != CURLE_OK || actualread != us_length) {
+      failf(data, "Failed to receive GSSAPI authentication token.");
+      gss_release_name(&gss_status, &server);
+      gss_release_buffer(&gss_status, &gss_recv_token);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    gss_token = &gss_recv_token;
+  }
+
+  gss_release_name(&gss_status, &server);
+
+  /* Everything is good so far, user was authenticated! */
+  gss_major_status = gss_inquire_context (&gss_minor_status, gss_context,
+                                          &gss_client_name, NULL, NULL, NULL,
+                                          NULL, NULL, NULL);
+  if(check_gss_err(data,gss_major_status,
+                   gss_minor_status,"gss_inquire_context")) {
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+    gss_release_name(&gss_status, &gss_client_name);
+    failf(data, "Failed to determine user name.");
+    return CURLE_COULDNT_CONNECT;
+  }
+  gss_major_status = gss_display_name(&gss_minor_status, gss_client_name,
+                                      &gss_send_token, NULL);
+  if(check_gss_err(data,gss_major_status,
+                   gss_minor_status,"gss_display_name")) {
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+    gss_release_name(&gss_status, &gss_client_name);
+    gss_release_buffer(&gss_status, &gss_send_token);
+    failf(data, "Failed to determine user name.");
+    return CURLE_COULDNT_CONNECT;
+  }
+  user=malloc(gss_send_token.length+1);
+  if(!user) {
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+    gss_release_name(&gss_status, &gss_client_name);
+    gss_release_buffer(&gss_status, &gss_send_token);
+    return CURLE_OUT_OF_MEMORY;
+  }
+
+  memcpy(user, gss_send_token.value, gss_send_token.length);
+  user[gss_send_token.length] = '\0';
+  gss_release_name(&gss_status, &gss_client_name);
+  gss_release_buffer(&gss_status, &gss_send_token);
+  infof(data, "SOCKS5 server authencticated user %s with gssapi.\n",user);
+  free(user);
+  user=NULL;
+
+  /* Do encryption */
+  socksreq[0] = 1;    /* gssapi subnegotiation version */
+  socksreq[1] = 2;    /* encryption message type */
+
+  gss_enc = 0; /* no data protection */
+  /* do confidentiality protection if supported */
+  if(gss_ret_flags & GSS_C_CONF_FLAG)
+    gss_enc = 2;
+  /* else do integrity protection */
+  else if(gss_ret_flags & GSS_C_INTEG_FLAG)
+    gss_enc = 1;
+
+  infof(data, "SOCKS5 server supports gssapi %s data protection.\n",
+        (gss_enc==0)?"no":((gss_enc==1)?"integrity":"confidentiality"));
+  /* force for the moment to no data protection */
+  gss_enc = 0;
+  /*
+   * Sending the encryption type in clear seems wrong. It should be
+   * protected with gss_seal()/gss_wrap(). See RFC1961 extract below
+   * The NEC reference implementations on which this is based is
+   * therefore at fault
+   *
+   *  +------+------+------+.......................+
+   *  + ver  | mtyp | len  |   token               |
+   *  +------+------+------+.......................+
+   *  + 0x01 | 0x02 | 0x02 | up to 2^16 - 1 octets |
+   *  +------+------+------+.......................+
+   *
+   *   Where:
+   *
+   *  - "ver" is the protocol version number, here 1 to represent the
+   *    first version of the SOCKS/GSS-API protocol
+   *
+   *  - "mtyp" is the message type, here 2 to represent a protection
+   *    -level negotiation message
+   *
+   *  - "len" is the length of the "token" field in octets
+   *
+   *  - "token" is the GSS-API encapsulated protection level
+   *
+   * The token is produced by encapsulating an octet containing the
+   * required protection level using gss_seal()/gss_wrap() with conf_req
+   * set to FALSE.  The token is verified using gss_unseal()/
+   * gss_unwrap().
+   *
+   */
+  if(data->set.socks5_gssapi_nec) {
+    us_length = htons((short)1);
+    memcpy(socksreq+2,&us_length,sizeof(short));
+  }
+  else {
+    gss_send_token.length = 1;
+    gss_send_token.value = malloc(1);
+    if(!gss_send_token.value) {
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_OUT_OF_MEMORY;
+    }
+    memcpy(gss_send_token.value, &gss_enc, 1);
+
+    gss_major_status = gss_wrap(&gss_minor_status, gss_context, 0,
+                                GSS_C_QOP_DEFAULT, &gss_send_token,
+                                &gss_conf_state, &gss_w_token);
+
+    if(check_gss_err(data,gss_major_status,gss_minor_status,"gss_wrap")) {
+      gss_release_buffer(&gss_status, &gss_send_token);
+      gss_release_buffer(&gss_status, &gss_w_token);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      failf(data, "Failed to wrap GSSAPI encryption value into token.");
+      return CURLE_COULDNT_CONNECT;
+    }
+    gss_release_buffer(&gss_status, &gss_send_token);
+
+    us_length = htons((short)gss_w_token.length);
+    memcpy(socksreq+2,&us_length,sizeof(short));
+  }
+
+  code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
+  if((code != CURLE_OK) || (4 != written)) {
+    failf(data, "Failed to send GSSAPI encryption request.");
+    gss_release_buffer(&gss_status, &gss_w_token);
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  if(data->set.socks5_gssapi_nec) {
+    memcpy(socksreq, &gss_enc, 1);
+    code = Curl_write_plain(conn, sock, socksreq, 1, &written);
+    if((code != CURLE_OK) || ( 1 != written)) {
+      failf(data, "Failed to send GSSAPI encryption type.");
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_COULDNT_CONNECT;
+    }
+  } else {
+    code = Curl_write_plain(conn, sock, (char *)gss_w_token.value,
+                            gss_w_token.length, &written);
+    if((code != CURLE_OK) || ((ssize_t)gss_w_token.length != written)) {
+      failf(data, "Failed to send GSSAPI encryption type.");
+      gss_release_buffer(&gss_status, &gss_w_token);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_COULDNT_CONNECT;
+    }
+    gss_release_buffer(&gss_status, &gss_w_token);
+  }
+
+  result=Curl_blockread_all(conn, sock, (char *)socksreq, 4,
+                            &actualread, timeout);
+  if(result != CURLE_OK || actualread != 4) {
+    failf(data, "Failed to receive GSSAPI encryption response.");
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  /* ignore the first (VER) byte */
+  if(socksreq[1] == 255) { /* status / message type */
+    failf(data, "User was rejected by the SOCKS5 server (%d %d).",
+          socksreq[0], socksreq[1]);
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  if(socksreq[1] != 2) { /* status / messgae type */
+    failf(data, "Invalid GSSAPI encryption response type (%d %d).",
+          socksreq[0], socksreq[1]);
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  memcpy(&us_length, socksreq+2, sizeof(short));
+  us_length = ntohs(us_length);
+
+  gss_recv_token.length= us_length;
+  gss_recv_token.value=malloc(gss_recv_token.length);
+  if(!gss_recv_token.value) {
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+    return CURLE_OUT_OF_MEMORY;
+  }
+  result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value,
+                            gss_recv_token.length,
+                            &actualread, timeout);
+
+  if(result != CURLE_OK || actualread != us_length) {
+    failf(data, "Failed to receive GSSAPI encryptrion type.");
+    gss_release_buffer(&gss_status, &gss_recv_token);
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  if(!data->set.socks5_gssapi_nec) {
+    gss_major_status = gss_unwrap(&gss_minor_status, gss_context,
+                                  &gss_recv_token, &gss_w_token,
+                                  0, GSS_C_QOP_DEFAULT);
+
+    if(check_gss_err(data,gss_major_status,gss_minor_status,"gss_unwrap")) {
+      gss_release_buffer(&gss_status, &gss_recv_token);
+      gss_release_buffer(&gss_status, &gss_w_token);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      failf(data, "Failed to unwrap GSSAPI encryption value into token.");
+      return CURLE_COULDNT_CONNECT;
+    }
+    gss_release_buffer(&gss_status, &gss_recv_token);
+
+    if(gss_w_token.length != 1) {
+      failf(data, "Invalid GSSAPI encryption response length (%d).",
+            gss_w_token.length);
+      gss_release_buffer(&gss_status, &gss_w_token);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    memcpy(socksreq,gss_w_token.value,gss_w_token.length);
+    gss_release_buffer(&gss_status, &gss_w_token);
+  }
+  else {
+    if(gss_recv_token.length != 1) {
+      failf(data, "Invalid GSSAPI encryption response length (%d).",
+            gss_recv_token.length);
+      gss_release_buffer(&gss_status, &gss_recv_token);
+      gss_delete_sec_context(&gss_status, &gss_context, NULL);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    memcpy(socksreq,gss_recv_token.value,gss_recv_token.length);
+    gss_release_buffer(&gss_status, &gss_recv_token);
+  }
+
+  infof(data, "SOCKS5 access with%s protection granted.\n",
+        (socksreq[0]==0)?"out gssapi data":
+        ((socksreq[0]==1)?" gssapi integrity":" gssapi confidentiality"));
+
+  conn->socks5_gssapi_enctype = socksreq[0];
+  if(socksreq[0] == 0)
+    gss_delete_sec_context(&gss_status, &gss_context, NULL);
+
+  return CURLE_OK;
+}
+#endif
diff --git a/lib/socks_sspi.c b/lib/socks_sspi.c
new file mode 100644
index 000000000..2a35af96b
--- /dev/null
+++ b/lib/socks_sspi.c
@@ -0,0 +1,649 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2009, Markus Moeller, <markus_moeller@compuserve.com>
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id$
+ ***************************************************************************/
+
+
+#include "setup.h"
+
+#ifdef USE_WINDOWS_SSPI
+#include <ntsecapi.h>
+
+#include <string.h>
+
+#ifdef NEED_MALLOC_H
+#include <malloc.h>
+#endif
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+
+#include "urldata.h"
+#include "sendf.h"
+#include "connect.h"
+#include "timeval.h"
+#include "socks.h"
+
+/* The last #include file should be: */
+#include "memdebug.h"
+
+/*
+ * Helper sspi error functions.
+ */
+typedef long OM_uint32;
+static int check_sspi_err(struct SessionHandle *data,
+                          OM_uint32 major_status,
+                          OM_uint32 minor_status,
+                          const char* function)
+{
+  char *txt;
+
+  if(major_status != SEC_E_OK &&
+     major_status != SEC_I_COMPLETE_AND_CONTINUE &&
+     major_status != SEC_I_COMPLETE_NEEDED &&
+     major_status != SEC_I_CONTINUE_NEEDED) {
+    failf(data, "SSPI error: %s failed: %d\n", function, major_status);
+    switch (major_status) {
+    case SEC_I_COMPLETE_AND_CONTINUE:
+      txt="SEC_I_COMPLETE_AND_CONTINUE";
+      break;
+    case SEC_I_COMPLETE_NEEDED:
+      txt="SEC_I_COMPLETE_NEEDED";
+      break;
+    case SEC_I_CONTINUE_NEEDED:
+      txt="SEC_I_CONTINUE_NEEDED";
+      break;
+    case SEC_I_INCOMPLETE_CREDENTIALS:
+      txt="SEC_I_INCOMPLETE_CREDENTIALS";
+      break;
+    case SEC_E_INSUFFICIENT_MEMORY:
+      txt="SEC_E_INSUFFICIENT_MEMORY";
+      break;
+    case SEC_E_INTERNAL_ERROR:
+      txt="SEC_E_INTERNAL_ERROR";
+      break;
+    case SEC_E_INVALID_HANDLE:
+      txt="SEC_E_INVALID_HANDLE";
+      break;
+    case SEC_E_INVALID_TOKEN:
+      txt="SEC_E_INVALID_TOKEN";
+      break;
+    case SEC_E_LOGON_DENIED:
+      txt="SEC_E_LOGON_DENIED";
+      break;
+    case SEC_E_NO_AUTHENTICATING_AUTHORITY:
+      txt="SEC_E_NO_AUTHENTICATING_AUTHORITY";
+      break;
+    case SEC_E_NO_CREDENTIALS:
+      txt="SEC_E_NO_CREDENTIALS";
+      break;
+    case SEC_E_TARGET_UNKNOWN:
+      txt="SEC_E_TARGET_UNKNOWN";
+      break;
+    case SEC_E_UNSUPPORTED_FUNCTION:
+      txt="SEC_E_UNSUPPORTED_FUNCTION";
+      break;
+    case SEC_E_WRONG_PRINCIPAL:
+      txt="SEC_E_WRONG_PRINCIPAL";
+      break;
+    default:
+      txt="Unknown error";
+
+    }
+    failf(data, "SSPI error: %s failed: %s\n", function, txt);
+    return(1);
+  }
+  return(0);
+}
+
+/* This is the SSPI-using version of this function */
+CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
+                                      struct connectdata *conn)
+{
+  struct SessionHandle *data = conn->data;
+  curl_socket_t sock = conn->sock[sockindex];
+  CURLcode code;
+  ssize_t actualread;
+  ssize_t written;
+  int result;
+  long timeout;
+  /* Needs GSSAPI authentication */
+  OM_uint32 sspi_major_status, sspi_minor_status=0;
+  OM_uint32 sspi_ret_flags=0;
+  int gss_enc;
+  SecBuffer sspi_send_token, sspi_recv_token, sspi_w_token[3];
+  SecBufferDesc input_desc, output_desc, wrap_desc;
+  SecPkgContext_Sizes sspi_sizes;
+  CredHandle cred_handle;
+  CtxtHandle sspi_context;
+  PCtxtHandle context_handle = NULL;
+  SecPkgCredentials_Names names;
+  TimeStamp expiry;
+  char *service_name=NULL;
+  u_short us_length;
+  ULONG qop;
+  unsigned char socksreq[4]; /* room for gssapi exchange header only */
+  char *service = data->set.str[STRING_SOCKS5_GSSAPI_SERVICE];
+
+  /* get timeout */
+  timeout = Curl_timeleft(conn, NULL, TRUE);
+
+  /*   GSSAPI request looks like
+   * +----+------+-----+----------------+
+   * |VER | MTYP | LEN |     TOKEN      |
+   * +----+------+----------------------+
+   * | 1  |  1   |  2  | up to 2^16 - 1 |
+   * +----+------+-----+----------------+
+   */
+
+  /* prepare service name */
+  if (strchr(service, '/')) {
+    service_name = malloc(strlen(service));
+    if(!service_name)
+      return CURLE_OUT_OF_MEMORY;
+    memcpy(service_name, service, strlen(service));
+  }
+  else {
+    service_name = malloc(strlen(service) + strlen(conn->proxy.name) + 2);
+    if(!service_name)
+      return CURLE_OUT_OF_MEMORY;
+    _snprintf(service_name,strlen(service) +strlen(conn->proxy.name)+2,"%s/%s",
+              service,conn->proxy.name);
+  }
+
+  input_desc.cBuffers = 1;
+  input_desc.pBuffers = &sspi_recv_token;
+  input_desc.ulVersion = SECBUFFER_VERSION;
+
+  sspi_recv_token.BufferType = SECBUFFER_TOKEN;
+  sspi_recv_token.cbBuffer = 0;
+  sspi_recv_token.pvBuffer = NULL;
+
+  output_desc.cBuffers = 1;
+  output_desc.pBuffers = &sspi_send_token;
+  output_desc.ulVersion = SECBUFFER_VERSION;
+
+  sspi_send_token.BufferType = SECBUFFER_TOKEN;
+  sspi_send_token.cbBuffer = 0;
+  sspi_send_token.pvBuffer = NULL;
+
+  wrap_desc.cBuffers = 3;
+  wrap_desc.pBuffers = sspi_w_token;
+  wrap_desc.ulVersion = SECBUFFER_VERSION;
+
+  cred_handle.dwLower = 0;
+  cred_handle.dwUpper = 0;
+
+  sspi_major_status = AcquireCredentialsHandle( NULL,
+                                                "Kerberos",
+                                                SECPKG_CRED_OUTBOUND,
+                                                NULL,
+                                                NULL,
+                                                NULL,
+                                                NULL,
+                                                &cred_handle,
+                                                &expiry);
+
+  if(check_sspi_err(data, sspi_major_status,sspi_minor_status,
+                    "AcquireCredentialsHandle") ) {
+    failf(data, "Failed to acquire credentials.");
+    free(service_name);
+    service_name=NULL;
+    FreeCredentialsHandle(&cred_handle);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  /* As long as we need to keep sending some context info, and there's no  */
+  /* errors, keep sending it...                                            */
+  for(;;) {
+
+    sspi_major_status = InitializeSecurityContext( &cred_handle,
+                                                   context_handle,
+                                                   service_name,
+                                                   ISC_REQ_MUTUAL_AUTH |
+                                                   ISC_REQ_ALLOCATE_MEMORY |
+                                                   ISC_REQ_CONFIDENTIALITY |
+                                                   ISC_REQ_REPLAY_DETECT,
+                                                   0,
+                                                   SECURITY_NATIVE_DREP,
+                                                   &input_desc,
+                                                   0,
+                                                   &sspi_context,
+                                                   &output_desc,
+                                                   &sspi_ret_flags,
+                                                   &expiry);
+
+    if(sspi_recv_token.pvBuffer) {
+      FreeContextBuffer(sspi_recv_token.pvBuffer);
+      sspi_recv_token.pvBuffer = NULL;
+      sspi_recv_token.cbBuffer = 0;
+    }
+
+    if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
+                      "InitializeSecurityContext") ){
+      free(service_name);
+      service_name=NULL;
+      FreeCredentialsHandle(&cred_handle);
+      DeleteSecurityContext(&sspi_context);
+      FreeContextBuffer(sspi_recv_token.pvBuffer);
+      failf(data, "Failed to initialise security context.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    if(sspi_send_token.cbBuffer != 0) {
+      socksreq[0] = 1;    /* gssapi subnegotiation version */
+      socksreq[1] = 1;    /* authentication message type */
+      us_length = htons((short)sspi_send_token.cbBuffer);
+      memcpy(socksreq+2, &us_length, sizeof(short));
+
+      code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
+      if((code != CURLE_OK) || (4 != written)) {
+        failf(data, "Failed to send SSPI authentication request.");
+        free(service_name);
+        service_name=NULL;
+        FreeContextBuffer(sspi_send_token.pvBuffer);
+        FreeContextBuffer(sspi_recv_token.pvBuffer);
+        FreeCredentialsHandle(&cred_handle);
+        DeleteSecurityContext(&sspi_context);
+        return CURLE_COULDNT_CONNECT;
+      }
+
+      code = Curl_write_plain(conn, sock, (char *)sspi_send_token.pvBuffer,
+                              sspi_send_token.cbBuffer, &written);
+      if((code != CURLE_OK) || (sspi_send_token.cbBuffer != written)) {
+        failf(data, "Failed to send SSPI authentication token.");
+        free(service_name);
+        service_name=NULL;
+        FreeContextBuffer(sspi_send_token.pvBuffer);
+        FreeContextBuffer(sspi_recv_token.pvBuffer);
+        FreeCredentialsHandle(&cred_handle);
+        DeleteSecurityContext(&sspi_context);
+        return CURLE_COULDNT_CONNECT;
+      }
+
+    }
+
+    FreeContextBuffer(sspi_send_token.pvBuffer);
+    sspi_send_token.pvBuffer = NULL;
+    sspi_send_token.cbBuffer = 0;
+    FreeContextBuffer(sspi_recv_token.pvBuffer);
+    sspi_recv_token.pvBuffer = NULL;
+    sspi_recv_token.cbBuffer = 0;
+    if(sspi_major_status != SEC_I_CONTINUE_NEEDED)  break;
+
+    /* analyse response */
+
+    /*   GSSAPI response looks like
+     * +----+------+-----+----------------+
+     * |VER | MTYP | LEN |     TOKEN      |
+     * +----+------+----------------------+
+     * | 1  |  1   |  2  | up to 2^16 - 1 |
+     * +----+------+-----+----------------+
+     */
+
+    result=Curl_blockread_all(conn, sock, (char *)socksreq, 4,
+                              &actualread, timeout);
+    if(result != CURLE_OK || actualread != 4) {
+      failf(data, "Failed to receive SSPI authentication response.");
+      free(service_name);
+      service_name=NULL;
+      FreeCredentialsHandle(&cred_handle);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    /* ignore the first (VER) byte */
+    if(socksreq[1] == 255) { /* status / message type */
+      failf(data, "User was rejected by the SOCKS5 server (%d %d).",
+            socksreq[0], socksreq[1]);
+      free(service_name);
+      service_name=NULL;
+      FreeCredentialsHandle(&cred_handle);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    if(socksreq[1] != 1) { /* status / messgae type */
+      failf(data, "Invalid SSPI authentication response type (%d %d).",
+            socksreq[0], socksreq[1]);
+      free(service_name);
+      service_name=NULL;
+      FreeCredentialsHandle(&cred_handle);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    memcpy(&us_length, socksreq+2, sizeof(short));
+    us_length = ntohs(us_length);
+
+    sspi_recv_token.cbBuffer = us_length;
+    sspi_recv_token.pvBuffer = malloc(us_length);
+
+    if(!sspi_recv_token.pvBuffer) {
+      free(service_name);
+      service_name=NULL;
+      FreeCredentialsHandle(&cred_handle);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_OUT_OF_MEMORY;
+    }
+    result = Curl_blockread_all(conn, sock, (char *)sspi_recv_token.pvBuffer,
+                                sspi_recv_token.cbBuffer,
+                                &actualread, timeout);
+
+    if(result != CURLE_OK || actualread != us_length) {
+      failf(data, "Failed to receive SSPI authentication token.");
+      free(service_name);
+      service_name=NULL;
+      FreeContextBuffer(sspi_recv_token.pvBuffer);
+      FreeCredentialsHandle(&cred_handle);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    context_handle = &sspi_context;
+  }
+
+  free(service_name);
+  service_name=NULL;
+
+  /* Everything is good so far, user was authenticated! */
+  sspi_major_status =
+    QueryCredentialsAttributes(&cred_handle, SECPKG_CRED_ATTR_NAMES, &names);
+  FreeCredentialsHandle(&cred_handle);
+  if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
+                    "QueryCredentialAttributes") ){
+    DeleteSecurityContext(&sspi_context);
+    FreeContextBuffer(names.sUserName);
+    failf(data, "Failed to determine user name.");
+    return CURLE_COULDNT_CONNECT;
+  }
+  infof(data, "SOCKS5 server authencticated user %s with gssapi.\n",
+        names.sUserName);
+  FreeContextBuffer(names.sUserName);
+
+  /* Do encryption */
+  socksreq[0] = 1;    /* gssapi subnegotiation version */
+  socksreq[1] = 2;    /* encryption message type */
+
+  gss_enc = 0; /* no data protection */
+  /* do confidentiality protection if supported */
+  if(sspi_ret_flags & ISC_REQ_CONFIDENTIALITY)
+    gss_enc = 2;
+  /* else do integrity protection */
+  else if(sspi_ret_flags & ISC_REQ_INTEGRITY)
+    gss_enc = 1;
+
+  infof(data, "SOCKS5 server supports gssapi %s data protection.\n",
+        (gss_enc==0)?"no":((gss_enc==1)?"integrity":"confidentiality") );
+  /* force to no data protection, avoid encryption/decryption for now */
+  gss_enc = 0;
+  /*
+   * Sending the encryption type in clear seems wrong. It should be
+   * protected with gss_seal()/gss_wrap(). See RFC1961 extract below
+   * The NEC reference implementations on which this is based is
+   * therefore at fault
+   *
+   *  +------+------+------+.......................+
+   *  + ver  | mtyp | len  |   token               |
+   *  +------+------+------+.......................+
+   *  + 0x01 | 0x02 | 0x02 | up to 2^16 - 1 octets |
+   *  +------+------+------+.......................+
+   *
+   *   Where:
+   *
+   *  - "ver" is the protocol version number, here 1 to represent the
+   *    first version of the SOCKS/GSS-API protocol
+   *
+   *  - "mtyp" is the message type, here 2 to represent a protection
+   *    -level negotiation message
+   *
+   *  - "len" is the length of the "token" field in octets
+   *
+   *  - "token" is the GSS-API encapsulated protection level
+   *
+   * The token is produced by encapsulating an octet containing the
+   * required protection level using gss_seal()/gss_wrap() with conf_req
+   * set to FALSE.  The token is verified using gss_unseal()/
+   * gss_unwrap().
+   *
+   */
+
+  if(data->set.socks5_gssapi_nec) {
+    us_length = htons((short)1);
+    memcpy(socksreq+2, &us_length, sizeof(short));
+  }
+  else {
+    sspi_major_status = QueryContextAttributes( &sspi_context,
+                                                SECPKG_ATTR_SIZES,
+                                                &sspi_sizes);
+    if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
+                      "QueryContextAttributes")) {
+      DeleteSecurityContext(&sspi_context);
+      failf(data, "Failed to query security context attributes.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    sspi_w_token[0].cbBuffer = sspi_sizes.cbSecurityTrailer;
+    sspi_w_token[0].BufferType = SECBUFFER_TOKEN;
+    sspi_w_token[0].pvBuffer = malloc(sspi_sizes.cbSecurityTrailer);
+
+    if(!sspi_w_token[0].pvBuffer) {
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_OUT_OF_MEMORY;
+    }
+
+    sspi_w_token[1].cbBuffer = 1;
+    sspi_w_token[1].pvBuffer = malloc(1);
+    if(!sspi_w_token[1].pvBuffer){
+      FreeContextBuffer(sspi_w_token[0].pvBuffer);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_OUT_OF_MEMORY;
+    }
+
+    memcpy(sspi_w_token[1].pvBuffer,&gss_enc,1);
+    sspi_w_token[2].BufferType = SECBUFFER_PADDING;
+    sspi_w_token[2].cbBuffer = sspi_sizes.cbBlockSize;
+    sspi_w_token[2].pvBuffer = malloc(sspi_sizes.cbBlockSize);
+    if(!sspi_w_token[2].pvBuffer) {
+      FreeContextBuffer(sspi_w_token[0].pvBuffer);
+      FreeContextBuffer(sspi_w_token[1].pvBuffer);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_OUT_OF_MEMORY;
+    }
+    sspi_major_status = EncryptMessage( &sspi_context,
+                                        KERB_WRAP_NO_ENCRYPT,
+                                        &wrap_desc,
+                                        0);
+    if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
+                      "EncryptMessage") ) {
+      FreeContextBuffer(sspi_w_token[0].pvBuffer);
+      FreeContextBuffer(sspi_w_token[1].pvBuffer);
+      FreeContextBuffer(sspi_w_token[2].pvBuffer);
+      DeleteSecurityContext(&sspi_context);
+      failf(data, "Failed to query security context attributes.");
+      return CURLE_COULDNT_CONNECT;
+    }
+    sspi_send_token.cbBuffer = sspi_w_token[0].cbBuffer
+      + sspi_w_token[1].cbBuffer
+      + sspi_w_token[2].cbBuffer;
+    sspi_send_token.pvBuffer = malloc(sspi_send_token.cbBuffer);
+    if(!sspi_send_token.pvBuffer) {
+      FreeContextBuffer(sspi_w_token[0].pvBuffer);
+      FreeContextBuffer(sspi_w_token[1].pvBuffer);
+      FreeContextBuffer(sspi_w_token[2].pvBuffer);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_OUT_OF_MEMORY;
+    }
+
+    memcpy(sspi_send_token.pvBuffer, sspi_w_token[0].pvBuffer,
+           sspi_w_token[0].cbBuffer);
+    memcpy((PUCHAR) sspi_send_token.pvBuffer +(int)sspi_w_token[0].cbBuffer,
+           sspi_w_token[1].pvBuffer, sspi_w_token[1].cbBuffer);
+    memcpy((PUCHAR) sspi_send_token.pvBuffer
+           +sspi_w_token[0].cbBuffer
+           +sspi_w_token[1].cbBuffer,
+           sspi_w_token[2].pvBuffer, sspi_w_token[2].cbBuffer);
+
+    FreeContextBuffer(sspi_w_token[0].pvBuffer);
+    sspi_w_token[0].pvBuffer = NULL;
+    sspi_w_token[0].cbBuffer = 0;
+    FreeContextBuffer(sspi_w_token[1].pvBuffer);
+    sspi_w_token[1].pvBuffer = NULL;
+    sspi_w_token[1].cbBuffer = 0;
+    FreeContextBuffer(sspi_w_token[2].pvBuffer);
+    sspi_w_token[2].pvBuffer = NULL;
+    sspi_w_token[2].cbBuffer = 0;
+
+    us_length = htons((short)sspi_send_token.cbBuffer);
+    memcpy(socksreq+2,&us_length,sizeof(short));
+  }
+
+  code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
+  if((code != CURLE_OK) || (4 != written)) {
+    failf(data, "Failed to send SSPI encryption request.");
+    FreeContextBuffer(sspi_send_token.pvBuffer);
+    DeleteSecurityContext(&sspi_context);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  if(data->set.socks5_gssapi_nec) {
+    memcpy(socksreq,&gss_enc,1);
+    code = Curl_write_plain(conn, sock, (char *)socksreq, 1, &written);
+    if((code != CURLE_OK) || (1 != written)) {
+      failf(data, "Failed to send SSPI encryption type.");
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_COULDNT_CONNECT;
+    }
+  } else {
+    code = Curl_write_plain(conn, sock, (char *)sspi_send_token.pvBuffer,
+                            sspi_send_token.cbBuffer, &written);
+    if((code != CURLE_OK) || (sspi_send_token.cbBuffer != written)) {
+      failf(data, "Failed to send SSPI encryption type.");
+      FreeContextBuffer(sspi_send_token.pvBuffer);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_COULDNT_CONNECT;
+    }
+    FreeContextBuffer(sspi_send_token.pvBuffer);
+  }
+
+  result=Curl_blockread_all(conn, sock, (char *)socksreq, 4,
+                            &actualread, timeout);
+  if(result != CURLE_OK || actualread != 4) {
+    failf(data, "Failed to receive SSPI encryption response.");
+    DeleteSecurityContext(&sspi_context);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  /* ignore the first (VER) byte */
+  if(socksreq[1] == 255) { /* status / message type */
+    failf(data, "User was rejected by the SOCKS5 server (%d %d).",
+          socksreq[0], socksreq[1]);
+    DeleteSecurityContext(&sspi_context);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  if(socksreq[1] != 2) { /* status / message type */
+    failf(data, "Invalid SSPI encryption response type (%d %d).",
+          socksreq[0], socksreq[1]);
+    DeleteSecurityContext(&sspi_context);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  memcpy(&us_length, socksreq+2, sizeof(short));
+  us_length = ntohs(us_length);
+
+  sspi_w_token[0].cbBuffer = us_length;
+  sspi_w_token[0].pvBuffer = malloc(us_length);
+  if(!sspi_w_token[0].pvBuffer) {
+    DeleteSecurityContext(&sspi_context);
+    return CURLE_OUT_OF_MEMORY;
+  }
+
+  result=Curl_blockread_all(conn, sock, (char *)sspi_w_token[0].pvBuffer,
+                            sspi_w_token[0].cbBuffer,
+                            &actualread, timeout);
+
+  if(result != CURLE_OK || actualread != us_length) {
+    failf(data, "Failed to receive SSPI encryption type.");
+    FreeContextBuffer(sspi_w_token[0].pvBuffer);
+    DeleteSecurityContext(&sspi_context);
+    return CURLE_COULDNT_CONNECT;
+  }
+
+
+  if(!data->set.socks5_gssapi_nec) {
+    wrap_desc.cBuffers = 2;
+    sspi_w_token[0].BufferType = SECBUFFER_STREAM;
+    sspi_w_token[1].BufferType = SECBUFFER_DATA;
+    sspi_w_token[1].cbBuffer = 0;
+    sspi_w_token[1].pvBuffer = NULL;
+
+    sspi_major_status = DecryptMessage(&sspi_context, &wrap_desc, 0, &qop);
+
+    if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
+                      "DecryptMessage")) {
+      FreeContextBuffer(sspi_w_token[0].pvBuffer);
+      FreeContextBuffer(sspi_w_token[1].pvBuffer);
+      DeleteSecurityContext(&sspi_context);
+      failf(data, "Failed to query security context attributes.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    if(sspi_w_token[1].cbBuffer != 1) {
+      failf(data, "Invalid SSPI encryption response length (%d).",
+            sspi_w_token[1].cbBuffer);
+      FreeContextBuffer(sspi_w_token[0].pvBuffer);
+      FreeContextBuffer(sspi_w_token[1].pvBuffer);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    memcpy(socksreq,sspi_w_token[1].pvBuffer,sspi_w_token[1].cbBuffer);
+    FreeContextBuffer(sspi_w_token[0].pvBuffer);
+    FreeContextBuffer(sspi_w_token[1].pvBuffer);
+  } else {
+    if(sspi_w_token[0].cbBuffer != 1) {
+      failf(data, "Invalid SSPI encryption response length (%d).",
+            sspi_w_token[0].cbBuffer);
+      FreeContextBuffer(sspi_w_token[0].pvBuffer);
+      DeleteSecurityContext(&sspi_context);
+      return CURLE_COULDNT_CONNECT;
+    }
+    memcpy(socksreq,sspi_w_token[0].pvBuffer,sspi_w_token[0].cbBuffer);
+    FreeContextBuffer(sspi_w_token[0].pvBuffer);
+  }
+
+  infof(data, "SOCKS5 access with%s protection granted.\n",
+        (socksreq[0]==0)?"out gssapi data":
+        ((socksreq[0]==1)?" gssapi integrity":" gssapi confidentiality"));
+
+  /* For later use if encryption is required
+     conn->socks5_gssapi_enctype = socksreq[0];
+     if (socksreq[0] != 0)
+     conn->socks5_sspi_context = sspi_context;
+     else {
+     DeleteSecurityContext(&sspi_context);
+     conn->socks5_sspi_context = sspi_context;
+     }
+  */
+  return CURLE_OK;
+}
+#endif
diff --git a/lib/url.c b/lib/url.c
index be5b20990..bd9a7e690 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -698,6 +698,20 @@ CURLcode Curl_init_userdefined(struct UserDefined *set)
   set->new_file_perms = 0644;    /* Default permissions */
   set->new_directory_perms = 0755; /* Default permissions */
 
+
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  /*
+   * disallow unprotected protection negotiation NEC reference implementation
+   * seem not to follow rfc1961 section 4.3/4.4
+   */
+  set->socks5_gssapi_nec = FALSE;
+  /* set default gssapi service name */
+  res = setstropt(&set->str[STRING_SOCKS5_GSSAPI_SERVICE],
+                  (char *) CURL_DEFAULT_SOCKS5_GSSAPI_SERVICE);
+  if (res != CURLE_OK)
+    return res;
+#endif
+
   /* This is our preferred CA cert bundle/path since install time */
 #if defined(CURL_CA_BUNDLE)
   res = setstropt(&set->str[STRING_SSL_CAFILE], (char *) CURL_CA_BUNDLE);
@@ -1463,6 +1477,23 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option,
     break;
 #endif
 
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  case CURLOPT_SOCKS5_GSSAPI_SERVICE:
+    /*
+     * Set gssapi service name
+     */
+    result = setstropt(&data->set.str[STRING_SOCKS5_GSSAPI_SERVICE],
+                       va_arg(param, char *));
+    break;
+
+  case CURLOPT_SOCKS5_GSSAPI_NEC:
+    /*
+     * set flag for nec socks5 support
+     */
+    data->set.socks5_gssapi_nec = (bool)(0 != va_arg(param, long));
+    break;
+#endif
+
   case CURLOPT_WRITEHEADER:
     /*
      * Custom pointer to pass the header write callback function
diff --git a/lib/url.h b/lib/url.h
index ec4da99c2..6cb0b7ec0 100644
--- a/lib/url.h
+++ b/lib/url.h
@@ -84,5 +84,6 @@ void Curl_close_connections(struct SessionHandle *data);
 void Curl_reset_reqproto(struct connectdata *conn);
 
 #define CURL_DEFAULT_PROXY_PORT 1080 /* default proxy port unless specified */
+#define CURL_DEFAULT_SOCKS5_GSSAPI_SERVICE "rcmd" /* default socks5 gssapi service */
 
 #endif
diff --git a/lib/urldata.h b/lib/urldata.h
index a06fb5eb4..15e4818f6 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -1051,6 +1051,9 @@ struct connectdata {
   } proto;
 
   int cselect_bits; /* bitmask of socket events */
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  int socks5_gssapi_enctype;
+#endif
 };
 
 /* The end of connectdata. */
@@ -1366,6 +1369,9 @@ enum dupstring {
   STRING_PROXYPASSWORD,   /* Proxy <password>, if used */
   STRING_NOPROXY,         /* List of hosts which should not use the proxy, if
                              used */
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  STRING_SOCKS5_GSSAPI_SERVICE,  /* GSSAPI service name */
+#endif
 
   /* -- end of strings -- */
   STRING_LAST /* not used, just an end-of-list marker */
@@ -1524,6 +1530,9 @@ struct UserDefined {
                                via an HTTP proxy */
   char *str[STRING_LAST]; /* array of strings, pointing to allocated memory */
   unsigned int scope;    /* address scope for IPv6 */
+#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
+  long socks5_gssapi_nec; /* flag to support nec socks5 server */
+#endif
 };
 
 struct Names {