/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 2012 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
* Copyright (C) 2009, 2011, 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 https://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.
*
***************************************************************************/
#include "curl_setup.h"
#if defined(USE_WINDOWS_SSPI) && !defined(CURL_DISABLE_PROXY)
#include "urldata.h"
#include "sendf.h"
#include "connect.h"
#include "strerror.h"
#include "timeval.h"
#include "socks.h"
#include "curl_sspi.h"
#include "curl_multibyte.h"
#include "warnless.h"
#include "strdup.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
/*
* Helper sspi error functions.
*/
static int check_sspi_err(struct connectdata *conn,
SECURITY_STATUS status,
const char *function)
{
if(status != SEC_E_OK &&
status != SEC_I_COMPLETE_AND_CONTINUE &&
status != SEC_I_COMPLETE_NEEDED &&
status != SEC_I_CONTINUE_NEEDED) {
failf(conn->data, "SSPI error: %s failed: %s", function,
Curl_sspi_strerror(conn, status));
return 1;
}
return 0;
}
/* This is the SSPI-using version of this function */
CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
struct connectdata *conn)
{
struct Curl_easy *data = conn->data;
curl_socket_t sock = conn->sock[sockindex];
CURLcode code;
ssize_t actualread;
ssize_t written;
int result;
/* Needs GSS-API authentication */
SECURITY_STATUS status;
unsigned long sspi_ret_flags = 0;
unsigned char 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;
unsigned short us_length;
unsigned long qop;
unsigned char socksreq[4]; /* room for GSS-API exchange header only */
const char *service = data->set.str[STRING_PROXY_SERVICE_NAME] ?
data->set.str[STRING_PROXY_SERVICE_NAME] : "rcmd";
const size_t service_length = strlen(service);
/* GSS-API request looks like
* +----+------+-----+----------------+
* |VER | MTYP | LEN | TOKEN |
* +----+------+----------------------+
* | 1 | 1 | 2 | up to 2^16 - 1 |
* +----+------+-----+----------------+
*/
/* prepare service name */
if(strchr(service, '/')) {
service_name = strdup(service);
if(!service_name)
return CURLE_OUT_OF_MEMORY;
}
else {
service_name = malloc(service_length +
strlen(conn->socks_proxy.host.name) + 2);
if(!service_name)
return CURLE_OUT_OF_MEMORY;
snprintf(service_name, service_length +
strlen(conn->socks_proxy.host.name) + 2, "%s/%s",
service, conn->socks_proxy.host.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;
status = s_pSecFn->AcquireCredentialsHandle(NULL,
(TCHAR *) TEXT("Kerberos"),
SECPKG_CRED_OUTBOUND,
NULL,
NULL,
NULL,
NULL,
&cred_handle,
&expiry);
if(check_sspi_err(conn, status, "AcquireCredentialsHandle")) {
failf(data, "Failed to acquire credentials.");
free(service_name);
s_pSecFn->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(;;) {
TCHAR *sname;
sname = Curl_convert_UTF8_to_tchar(service_name);
if(!sname)
return CURLE_OUT_OF_MEMORY;
status = s_pSecFn->InitializeSecurityContext(&cred_handle,
context_handle,
sname,
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);
Curl_unicodefree(sname);
if(sspi_recv_token.pvBuffer) {
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
sspi_recv_token.pvBuffer = NULL;
sspi_recv_token.cbBuffer = 0;
}
if(check_sspi_err(conn, status, "InitializeSecurityContext")) {
free(service_name);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
if(sspi_recv_token.pvBuffer)
s_pSecFn->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; /* GSS-API 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 || (4 != written)) {
failf(data, "Failed to send SSPI authentication request.");
free(service_name);
if(sspi_send_token.pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
if(sspi_recv_token.pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->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 || (sspi_send_token.cbBuffer != (size_t)written)) {
failf(data, "Failed to send SSPI authentication token.");
free(service_name);
if(sspi_send_token.pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
if(sspi_recv_token.pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
}
if(sspi_send_token.pvBuffer) {
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
sspi_send_token.pvBuffer = NULL;
}
sspi_send_token.cbBuffer = 0;
if(sspi_recv_token.pvBuffer) {
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
sspi_recv_token.pvBuffer = NULL;
}
sspi_recv_token.cbBuffer = 0;
if(status != SEC_I_CONTINUE_NEEDED)
break;
/* analyse response */
/* GSS-API 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);
if(result || (actualread != 4)) {
failf(data, "Failed to receive SSPI authentication response.");
free(service_name);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->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 (%u %u).",
(unsigned int)socksreq[0], (unsigned int)socksreq[1]);
free(service_name);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
if(socksreq[1] != 1) { /* status / messgae type */
failf(data, "Invalid SSPI authentication response type (%u %u).",
(unsigned int)socksreq[0], (unsigned int)socksreq[1]);
free(service_name);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->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);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_OUT_OF_MEMORY;
}
result = Curl_blockread_all(conn, sock, (char *)sspi_recv_token.pvBuffer,
sspi_recv_token.cbBuffer, &actualread);
if(result || (actualread != us_length)) {
failf(data, "Failed to receive SSPI authentication token.");
free(service_name);
if(sspi_recv_token.pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
context_handle = &sspi_context;
}
free(service_name);
/* Everything is good so far, user was authenticated! */
status = s_pSecFn->QueryCredentialsAttributes(&cred_handle,
SECPKG_CRED_ATTR_NAMES,
&names);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
if(check_sspi_err(conn, status, "QueryCredentialAttributes")) {
s_pSecFn->DeleteSecurityContext(&sspi_context);
s_pSecFn->FreeContextBuffer(names.sUserName);
failf(data, "Failed to determine user name.");
return CURLE_COULDNT_CONNECT;
}
infof(data, "SOCKS5 server authencticated user %s with GSS-API.\n",
names.sUserName);
s_pSecFn->FreeContextBuffer(names.sUserName);
/* Do encryption */
socksreq[0] = 1; /* GSS-API 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 GSS-API %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 {
status = s_pSecFn->QueryContextAttributes(&sspi_context,
SECPKG_ATTR_SIZES,
&sspi_sizes);
if(check_sspi_err(conn, status, "QueryContextAttributes")) {
s_pSecFn->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) {
s_pSecFn->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) {
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->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) {
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_OUT_OF_MEMORY;
}
status = s_pSecFn->EncryptMessage(&sspi_context,
KERB_WRAP_NO_ENCRYPT,
&wrap_desc,
0);
if(check_sspi_err(conn, status, "EncryptMessage")) {
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[2].pvBuffer);
s_pSecFn->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) {
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[2].pvBuffer);
s_pSecFn->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);
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
sspi_w_token[0].pvBuffer = NULL;
sspi_w_token[0].cbBuffer = 0;
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
sspi_w_token[1].pvBuffer = NULL;
sspi_w_token[1].cbBuffer = 0;
s_pSecFn->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 || (4 != written)) {
failf(data, "Failed to send SSPI encryption request.");
if(sspi_send_token.pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
s_pSecFn->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 || (1 != written)) {
failf(data, "Failed to send SSPI encryption type.");
s_pSecFn->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 || (sspi_send_token.cbBuffer != (size_t)written)) {
failf(data, "Failed to send SSPI encryption type.");
if(sspi_send_token.pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
if(sspi_send_token.pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
}
result = Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread);
if(result || (actualread != 4)) {
failf(data, "Failed to receive SSPI encryption response.");
s_pSecFn->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 (%u %u).",
(unsigned int)socksreq[0], (unsigned int)socksreq[1]);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
if(socksreq[1] != 2) { /* status / message type */
failf(data, "Invalid SSPI encryption response type (%u %u).",
(unsigned int)socksreq[0], (unsigned int)socksreq[1]);
s_pSecFn->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) {
s_pSecFn->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);
if(result || (actualread != us_length)) {
failf(data, "Failed to receive SSPI encryption type.");
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->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;
status = s_pSecFn->DecryptMessage(&sspi_context,
&wrap_desc,
0,
&qop);
if(check_sspi_err(conn, status, "DecryptMessage")) {
if(sspi_w_token[0].pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
if(sspi_w_token[1].pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->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 (%lu).",
(unsigned long)sspi_w_token[1].cbBuffer);
if(sspi_w_token[0].pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
if(sspi_w_token[1].pvBuffer)
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
memcpy(socksreq, sspi_w_token[1].pvBuffer, sspi_w_token[1].cbBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
}
else {
if(sspi_w_token[0].cbBuffer != 1) {
failf(data, "Invalid SSPI encryption response length (%lu).",
(unsigned long)sspi_w_token[0].cbBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
memcpy(socksreq, sspi_w_token[0].pvBuffer, sspi_w_token[0].cbBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
}
infof(data, "SOCKS5 access with%s protection granted.\n",
(socksreq[0] == 0)?"out GSS-API data":
((socksreq[0] == 1)?" GSS-API integrity":" GSS-API 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 {
s_pSecFn->DeleteSecurityContext(&sspi_context);
conn->socks5_sspi_context = sspi_context;
}
*/
return CURLE_OK;
}
#endif