curl/lib/socks_gssapi.c

549 строки
20 KiB
C

/***************************************************************************
* _ _ ____ _
* 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"
#ifndef CURL_DISABLE_PROXY
#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 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
#endif /* CURL_DISABLE_PROXY */