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ec9e9f38b1
curl/lib/curl_schannel.c
Marc Hoersken ec9e9f38b1 schannel: Implemented SSL/TLS renegotiation 
Updated TODO information and added related MSDN articles
2012-06-11 19:00:34 +02:00

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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 2012, Marc Hoersken, <info@marc-hoersken.de>, et al.
*
* 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.
*
***************************************************************************/
/*
* Source file for all SChannel-specific code for the TLS/SSL layer. No code
* but sslgen.c should ever call or use these functions.
*
*/
/*
* Based upon the PolarSSL implementation in polarssl.c and polarssl.h:
* Copyright (C) 2010, 2011, Hoi-Ho Chan, <hoiho.chan@gmail.com>
*
* Based upon the CyaSSL implementation in cyassl.c and cyassl.h:
* Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* Thanks for code and inspiration!
*/
/*
* TODO list for TLS/SSL implementation:
* - implement write buffering
* - implement SSL/TLS shutdown
* - implement client certificate authentication
* - implement custom server certificate validation
* - implement cipher/algorithm option
*
* Related articles on MSDN:
* - Getting a Certificate for Schannel
* http://msdn.microsoft.com/en-us/library/windows/desktop/aa375447.aspx
* - Specifying Schannel Ciphers and Cipher Strengths
* http://msdn.microsoft.com/en-us/library/windows/desktop/aa380161.aspx
*/
#include "setup.h"
#ifdef USE_WINDOWS_SSPI
#ifdef USE_SCHANNEL
#include "urldata.h"
#include "curl_sspi.h"
#include "curl_schannel.h"
#include "sslgen.h"
#include "sendf.h"
#include "connect.h" /* for the connect timeout */
#include "select.h" /* for the socket readyness */
#include "inet_pton.h" /* for IP addr SNI check */
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
#include "curl_memory.h"
/* The last #include file should be: */
#include "memdebug.h"
/* Uncomment to force verbose output
* #define infof(x, y, ...) printf(y, __VA_ARGS__)
* #define failf(x, y, ...) printf(y, __VA_ARGS__)
*/
static Curl_recv schannel_recv;
static Curl_send schannel_send;
static CURLcode
schannel_connect_step1(struct connectdata *conn, int sockindex) {
ssize_t write = -1;
struct SessionHandle *data = conn->data;
struct ssl_connect_data* connssl = &conn->ssl[sockindex];
SecBuffer outbuf;
SecBufferDesc outbuf_desc;
SCHANNEL_CRED schannel_cred;
SECURITY_STATUS sspi_status = SEC_E_OK;
curl_schannel_cred *old_cred = NULL;
struct in_addr addr;
#ifdef ENABLE_IPV6
struct in6_addr addr6;
#endif
infof(data, "schannel: connecting to %s:%d (step 1/3)\n",
conn->host.name, conn->remote_port);
/* check for an existing re-usable credential handle */
if(!Curl_ssl_getsessionid(conn, &old_cred, NULL)) {
connssl->cred = old_cred;
infof(data, "schannel: re-using existing credential handle\n");
}
else {
/* setup Schannel API options */
memset(&schannel_cred, 0, sizeof(schannel_cred));
schannel_cred.dwVersion = SCHANNEL_CRED_VERSION;
if(data->set.ssl.verifypeer) {
schannel_cred.dwFlags = SCH_CRED_AUTO_CRED_VALIDATION |
SCH_CRED_REVOCATION_CHECK_CHAIN;
infof(data, "schannel: checking server certificate and revocation\n");
}
else {
schannel_cred.dwFlags = SCH_CRED_MANUAL_CRED_VALIDATION |
SCH_CRED_IGNORE_NO_REVOCATION_CHECK |
SCH_CRED_IGNORE_REVOCATION_OFFLINE;
infof(data, "schannel: disable server certificate and revocation checks\n");
}
if(Curl_inet_pton(AF_INET, conn->host.name, &addr) ||
#ifdef ENABLE_IPV6
Curl_inet_pton(AF_INET6, conn->host.name, &addr6) ||
#endif
data->set.ssl.verifyhost < 2) {
schannel_cred.dwFlags |= SCH_CRED_NO_SERVERNAME_CHECK;
infof(data, "schannel: using IP address, disable SNI servername check\n");
}
switch(data->set.ssl.version) {
case CURL_SSLVERSION_TLSv1:
schannel_cred.grbitEnabledProtocols = SP_PROT_TLS1_0_CLIENT |
SP_PROT_TLS1_1_CLIENT |
SP_PROT_TLS1_2_CLIENT;
break;
case CURL_SSLVERSION_SSLv3:
schannel_cred.grbitEnabledProtocols = SP_PROT_SSL3_CLIENT;
break;
case CURL_SSLVERSION_SSLv2:
schannel_cred.grbitEnabledProtocols = SP_PROT_SSL2_CLIENT;
break;
}
/* allocate memory for the re-usable credential handle */
connssl->cred = malloc(sizeof(curl_schannel_cred));
if (!connssl->cred) {
failf(data, "schannel: unable to allocate memory");
return CURLE_OUT_OF_MEMORY;
}
memset(connssl->cred, 0, sizeof(curl_schannel_cred));
/* http://msdn.microsoft.com/en-us/library/windows/desktop/aa374716.aspx */
sspi_status = s_pSecFn->AcquireCredentialsHandleA(NULL,
UNISP_NAME_A, SECPKG_CRED_OUTBOUND, NULL, &schannel_cred, NULL, NULL,
&connssl->cred->cred_handle, &connssl->cred->time_stamp);
if(sspi_status != SEC_E_OK) {
if(sspi_status == SEC_E_WRONG_PRINCIPAL)
failf(data, "schannel: SNI or certificate check failed\n");
else
failf(data, "schannel: AcquireCredentialsHandleA failed: %d\n",
sspi_status);
free(connssl->cred);
connssl->cred = NULL;
return CURLE_SSL_CONNECT_ERROR;
}
}
/* setup output buffer */
outbuf.pvBuffer = NULL;
outbuf.cbBuffer = 0;
outbuf.BufferType = SECBUFFER_EMPTY;
outbuf_desc.pBuffers = &outbuf;
outbuf_desc.cBuffers = 1;
outbuf_desc.ulVersion = SECBUFFER_VERSION;
/* setup request flags */
connssl->req_flags = ISC_REQ_SEQUENCE_DETECT | ISC_REQ_REPLAY_DETECT |
ISC_REQ_CONFIDENTIALITY | ISC_REQ_EXTENDED_ERROR |
ISC_REQ_ALLOCATE_MEMORY | ISC_REQ_STREAM;
/* allocate memory for the security context handle */
connssl->ctxt = malloc(sizeof(curl_schannel_ctxt));
if (!connssl->ctxt) {
failf(data, "schannel: unable to allocate memory");
return CURLE_OUT_OF_MEMORY;
}
memset(connssl->ctxt, 0, sizeof(curl_schannel_ctxt));
/* http://msdn.microsoft.com/en-us/library/windows/desktop/aa375924.aspx */
sspi_status = s_pSecFn->InitializeSecurityContextA(
&connssl->cred->cred_handle, NULL, conn->host.name,
connssl->req_flags, 0, 0, NULL, 0, &connssl->ctxt->ctxt_handle,
&outbuf_desc, &connssl->ret_flags, &connssl->ctxt->time_stamp);
if(sspi_status != SEC_I_CONTINUE_NEEDED) {
if(sspi_status == SEC_E_WRONG_PRINCIPAL)
failf(data, "schannel: SNI or certificate check failed\n");
else
failf(data, "schannel: initial InitializeSecurityContextA failed: %d\n",
sspi_status);
free(connssl->ctxt);
connssl->ctxt = NULL;
return CURLE_SSL_CONNECT_ERROR;
}
infof(data, "schannel: sending initial handshake data: %d ...\n",
outbuf.cbBuffer);
/* send initial handshake data which is now stored in output buffer */
write = swrite(conn->sock[sockindex], outbuf.pvBuffer, outbuf.cbBuffer);
s_pSecFn->FreeContextBuffer(outbuf.pvBuffer);
if(write != outbuf.cbBuffer) {
failf(data, "schannel: failed to send initial handshake data: %d\n", write);
return CURLE_SSL_CONNECT_ERROR;
}
infof(data, "schannel: sent initial handshake data: %d\n", write);
/* continue to second handshake step */
connssl->connecting_state = ssl_connect_2;
return CURLE_OK;
}
static CURLcode
schannel_connect_step2(struct connectdata *conn, int sockindex) {
int i;
ssize_t read = -1, write = -1;
struct SessionHandle *data = conn->data;
struct ssl_connect_data* connssl = &conn->ssl[sockindex];
SecBuffer outbuf[2];
SecBufferDesc outbuf_desc;
SecBuffer inbuf[2];
SecBufferDesc inbuf_desc;
SECURITY_STATUS sspi_status = SEC_E_OK;
infof(data, "schannel: connecting to %s:%d (step 2/3)\n",
conn->host.name, conn->remote_port);
/* buffer to store previously received and encrypted data */
if(connssl->encdata_buffer == NULL) {
connssl->encdata_offset = 0;
connssl->encdata_length = 4096;
connssl->encdata_buffer = malloc(connssl->encdata_length);
if(connssl->encdata_buffer == NULL) {
failf(data, "schannel: unable to allocate memory");
return CURLE_OUT_OF_MEMORY;
}
}
/* read encrypted handshake data from socket */
read = sread(conn->sock[sockindex],
connssl->encdata_buffer + connssl->encdata_offset,
connssl->encdata_length - connssl->encdata_offset);
if(read < 0 && connssl->connecting_state != ssl_connect_2_writing) {
connssl->connecting_state = ssl_connect_2_reading;
infof(data, "schannel: failed to receive handshake, waiting for more: %d\n",
read);
return CURLE_OK;
}
else if(read == 0 && connssl->connecting_state != ssl_connect_2_writing) {
failf(data, "schannel: failed to receive handshake, connection failed\n");
return CURLE_SSL_CONNECT_ERROR;
}
else if(read > 0) {
/* increase encrypted data buffer offset */
connssl->encdata_offset += read;
}
infof(data, "schannel: encrypted data buffer %d/%d\n",
connssl->encdata_offset, connssl->encdata_length);
/* setup input buffers */
inbuf[0].pvBuffer = malloc(connssl->encdata_offset);
inbuf[0].cbBuffer = connssl->encdata_offset;
inbuf[0].BufferType = SECBUFFER_TOKEN;
inbuf[1].pvBuffer = NULL;
inbuf[1].cbBuffer = 0;
inbuf[1].BufferType = SECBUFFER_EMPTY;
inbuf_desc.pBuffers = &inbuf[0];
inbuf_desc.cBuffers = 2;
inbuf_desc.ulVersion = SECBUFFER_VERSION;
/* setup output buffers */
outbuf[0].pvBuffer = NULL;
outbuf[0].cbBuffer = 0;
outbuf[0].BufferType = SECBUFFER_TOKEN;
outbuf[1].pvBuffer = NULL;
outbuf[1].cbBuffer = 0;
outbuf[1].BufferType = SECBUFFER_ALERT;
outbuf_desc.pBuffers = &outbuf[0];
outbuf_desc.cBuffers = 2;
outbuf_desc.ulVersion = SECBUFFER_VERSION;
if(inbuf[0].pvBuffer == NULL) {
failf(data, "schannel: unable to allocate memory");
return CURLE_OUT_OF_MEMORY;
}
/* copy received handshake data into input buffer */
memcpy(inbuf[0].pvBuffer, connssl->encdata_buffer, connssl->encdata_offset);
/* http://msdn.microsoft.com/en-us/library/windows/desktop/aa375924.aspx */
sspi_status = s_pSecFn->InitializeSecurityContextA(
&connssl->cred->cred_handle, &connssl->ctxt->ctxt_handle,
conn->host.name, connssl->req_flags, 0, 0, &inbuf_desc, 0, NULL,
&outbuf_desc, &connssl->ret_flags, &connssl->ctxt->time_stamp);
/* free buffer for received handshake data */
free(inbuf[0].pvBuffer);
/* check if the handshake was incomplete */
if(sspi_status == SEC_E_INCOMPLETE_MESSAGE) {
connssl->connecting_state = ssl_connect_2_reading;
infof(data, "schannel: received incomplete message, need more data: %d\n",
sspi_status);
return CURLE_OK;
}
/* check if the handshake needs to be continued */
if(sspi_status == SEC_I_CONTINUE_NEEDED || sspi_status == SEC_E_OK) {
for(i = 0; i < 2; i++) {
/* search for handshake tokens that need to be send */
if(outbuf[i].BufferType = SECBUFFER_TOKEN && outbuf[i].cbBuffer > 0) {
infof(data, "schannel: sending next handshake data: %d ...\n",
outbuf[i].cbBuffer);
/* send handshake token to server */
write = swrite(conn->sock[sockindex],
outbuf[i].pvBuffer, outbuf[i].cbBuffer);
if(write != outbuf[i].cbBuffer) {
failf(data, "schannel: failed to send next handshake data: %d\n",
write);
return CURLE_SSL_CONNECT_ERROR;
}
}
/* free obsolete buffer */
if(outbuf[i].pvBuffer != NULL) {
s_pSecFn->FreeContextBuffer(outbuf[i].pvBuffer);
}
}
}
else {
if(sspi_status == SEC_E_WRONG_PRINCIPAL)
failf(data, "schannel: SNI or certificate check failed\n");
else
failf(data, "schannel: next InitializeSecurityContextA failed: %d\n",
sspi_status);
return CURLE_SSL_CONNECT_ERROR;
}
/* check if there was additional remaining encrypted data */
if(inbuf[1].BufferType = SECBUFFER_EXTRA) {
infof(data, "schannel: encrypted data length: %d\n", inbuf[1].cbBuffer);
/* check if the remaining data is less than the total amount
* and therefore begins after the already processed data
*/
if(connssl->encdata_offset > inbuf[1].cbBuffer) {
memmove(connssl->encdata_buffer,
(connssl->encdata_buffer + connssl->encdata_offset) -
inbuf[1].cbBuffer, inbuf[1].cbBuffer);
connssl->encdata_offset = inbuf[1].cbBuffer;
}
}
else {
connssl->encdata_offset = 0;
}
/* check if the handshake needs to be continued */
if(sspi_status == SEC_I_CONTINUE_NEEDED) {
connssl->connecting_state = ssl_connect_2_reading;
return CURLE_OK;
}
/* check if the handshake is complete */
if(sspi_status == SEC_E_OK) {
connssl->connecting_state = ssl_connect_3;
infof(data, "schannel: handshake complete\n");
}
return CURLE_OK;
}
static CURLcode
schannel_connect_step3(struct connectdata *conn, int sockindex) {
CURLcode retcode = CURLE_OK;
struct SessionHandle *data = conn->data;
struct ssl_connect_data *connssl = &conn->ssl[sockindex];
curl_schannel_cred *old_cred = NULL;
int incache;
DEBUGASSERT(ssl_connect_3 == connssl->connecting_state);
infof(data, "schannel: connecting to %s:%d (step 3/3)\n",
conn->host.name, conn->remote_port);
/* check if the required context attributes are met */
if(connssl->ret_flags != connssl->req_flags) {
if(!(connssl->ret_flags & ISC_RET_SEQUENCE_DETECT))
failf(data, "schannel: failed to setup sequence detection\n");
if(!(connssl->ret_flags & ISC_RET_REPLAY_DETECT))
failf(data, "schannel: failed to setup replay detection\n");
if(!(connssl->ret_flags & ISC_RET_CONFIDENTIALITY))
failf(data, "schannel: failed to setup confidentiality\n");
if(!(connssl->ret_flags & ISC_RET_EXTENDED_ERROR))
failf(data, "schannel: failed to setup extended errors\n");
if(!(connssl->ret_flags & ISC_RET_ALLOCATED_MEMORY))
failf(data, "schannel: failed to setup memory allocation\n");
if(!(connssl->ret_flags & ISC_RET_STREAM))
failf(data, "schannel: failed to setup stream orientation\n");
return CURLE_SSL_CONNECT_ERROR;
}
/* save the current session data for possible re-use */
incache = !(Curl_ssl_getsessionid(conn, &old_cred, NULL));
if(incache) {
if(old_cred != connssl->cred) {
infof(data, "schannel: old credential handle is stale, removing\n");
Curl_ssl_delsessionid(conn, old_cred);
incache = FALSE;
}
}
if(!incache) {
retcode = Curl_ssl_addsessionid(conn, connssl->cred,
sizeof(curl_schannel_cred));
if(retcode) {
failf(data, "schannel: failed to store credential handle\n");
return retcode;
}
else {
infof(data, "schannel: stored crendential handle\n");
}
}
connssl->connecting_state = ssl_connect_done;
return CURLE_OK;
}
static CURLcode
schannel_connect_common(struct connectdata *conn, int sockindex,
bool nonblocking, bool *done) {
CURLcode retcode;
struct SessionHandle *data = conn->data;
struct ssl_connect_data *connssl = &conn->ssl[sockindex];
curl_socket_t sockfd = conn->sock[sockindex];
long timeout_ms;
int what;
/* check if the connection has already been established */
if(ssl_connection_complete == connssl->state) {
*done = TRUE;
return CURLE_OK;
}
if(ssl_connect_1 == connssl->connecting_state) {
/* check out how much more time we're allowed */
timeout_ms = Curl_timeleft(data, NULL, TRUE);
if(timeout_ms < 0) {
/* no need to continue if time already is up */
failf(data, "SSL connection timeout");
return CURLE_OPERATION_TIMEDOUT;
}
retcode = schannel_connect_step1(conn, sockindex);
if(retcode)
return retcode;
}
while(ssl_connect_2 == connssl->connecting_state ||
ssl_connect_2_reading == connssl->connecting_state ||
ssl_connect_2_writing == connssl->connecting_state) {
/* check out how much more time we're allowed */
timeout_ms = Curl_timeleft(data, NULL, TRUE);
if(timeout_ms < 0) {
/* no need to continue if time already is up */
failf(data, "SSL connection timeout");
return CURLE_OPERATION_TIMEDOUT;
}
/* if ssl is expecting something, check if it's available. */
if(connssl->connecting_state == ssl_connect_2_reading
|| connssl->connecting_state == ssl_connect_2_writing) {
curl_socket_t writefd = ssl_connect_2_writing ==
connssl->connecting_state ? sockfd : CURL_SOCKET_BAD;
curl_socket_t readfd = ssl_connect_2_reading ==
connssl->connecting_state ? sockfd : CURL_SOCKET_BAD;
what = Curl_socket_ready(readfd, writefd, nonblocking ? 0 : timeout_ms);
if(what < 0) {
/* fatal error */
failf(data, "select/poll on SSL socket, errno: %d", SOCKERRNO);
return CURLE_SSL_CONNECT_ERROR;
}
else if(0 == what) {
if(nonblocking) {
*done = FALSE;
return CURLE_OK;
}
else {
/* timeout */
failf(data, "SSL connection timeout");
return CURLE_OPERATION_TIMEDOUT;
}
}
/* socket is readable or writable */
}
/* Run transaction, and return to the caller if it failed or if
* this connection is part of a multi handle and this loop would
* execute again. This permits the owner of a multi handle to
* abort a connection attempt before step2 has completed while
* ensuring that a client using select() or epoll() will always
* have a valid fdset to wait on.
*/
retcode = schannel_connect_step2(conn, sockindex);
if(retcode || (nonblocking &&
(ssl_connect_2 == connssl->connecting_state ||
ssl_connect_2_reading == connssl->connecting_state ||
ssl_connect_2_writing == connssl->connecting_state)))
return retcode;
} /* repeat step2 until all transactions are done. */
if(ssl_connect_3 == connssl->connecting_state) {
retcode = schannel_connect_step3(conn, sockindex);
if(retcode)
return retcode;
}
if(ssl_connect_done == connssl->connecting_state) {
connssl->state = ssl_connection_complete;
conn->recv[sockindex] = schannel_recv;
conn->send[sockindex] = schannel_send;
*done = TRUE;
}
else
*done = FALSE;
/* reset our connection state machine */
connssl->connecting_state = ssl_connect_1;
return CURLE_OK;
}
static ssize_t
schannel_send(struct connectdata *conn, int sockindex,
const void *buf, size_t len, CURLcode *err) {
ssize_t ret = -1;
size_t data_len = 0;
unsigned char *data = NULL;
struct ssl_connect_data *connssl = &conn->ssl[sockindex];
SecBuffer outbuf[4];
SecBufferDesc outbuf_desc;
SECURITY_STATUS sspi_status = SEC_E_OK;
/* check if the maximum stream sizes were queried */
if(connssl->stream_sizes.cbMaximumMessage == 0) {
sspi_status = s_pSecFn->QueryContextAttributesA(
&connssl->ctxt->ctxt_handle,
SECPKG_ATTR_STREAM_SIZES, &connssl->stream_sizes);
if(sspi_status != SEC_E_OK) {
*err = CURLE_SEND_ERROR;
return -1;
}
}
/* check if the buffer is longer than the maximum message length */
if(len > connssl->stream_sizes.cbMaximumMessage) {
*err = CURLE_SEND_ERROR;
return -1;
}
/* calculate the complete message length and allocate a buffer for it */
data_len = connssl->stream_sizes.cbHeader + len +
connssl->stream_sizes.cbTrailer;
data = (unsigned char*) malloc(data_len);
if(data == NULL) {
*err = CURLE_OUT_OF_MEMORY;
return -1;
}
/* setup output buffers (header, data, trailer, empty) */
outbuf[0].pvBuffer = data;
outbuf[0].cbBuffer = connssl->stream_sizes.cbHeader;
outbuf[0].BufferType = SECBUFFER_STREAM_HEADER;
outbuf[1].pvBuffer = data + connssl->stream_sizes.cbHeader;
outbuf[1].cbBuffer = len;
outbuf[1].BufferType = SECBUFFER_DATA;
outbuf[2].pvBuffer = data + connssl->stream_sizes.cbHeader + len;
outbuf[2].cbBuffer = connssl->stream_sizes.cbTrailer;
outbuf[2].BufferType = SECBUFFER_STREAM_TRAILER;
outbuf[3].pvBuffer = NULL;
outbuf[3].cbBuffer = 0;
outbuf[3].BufferType = SECBUFFER_EMPTY;
outbuf_desc.pBuffers = &outbuf[0];
outbuf_desc.cBuffers = 4;
outbuf_desc.ulVersion = SECBUFFER_VERSION;
/* copy data into output buffer */
memcpy(outbuf[1].pvBuffer, buf, len);
/* http://msdn.microsoft.com/en-us/library/windows/desktop/aa375390.aspx */
sspi_status = s_pSecFn->EncryptMessage(&connssl->ctxt->ctxt_handle, 0,
&outbuf_desc, 0);
/* check if the message was encrypted */
if(sspi_status == SEC_E_OK) {
/* send the encrypted message including header, data and trailer */
len = outbuf[0].cbBuffer + outbuf[1].cbBuffer + outbuf[2].cbBuffer;
ret = swrite(conn->sock[sockindex], data, len);
/* TODO: implement write buffering */
}
else if(sspi_status == SEC_E_INSUFFICIENT_MEMORY) {
*err = CURLE_OUT_OF_MEMORY;
}
else{
*err = CURLE_SEND_ERROR;
}
free(data);
return ret;
}
static ssize_t
schannel_recv(struct connectdata *conn, int sockindex,
char *buf, size_t len, CURLcode *err) {
int i = 0;
size_t size = 0;
ssize_t read = 0, ret = -1;
CURLcode retcode;
struct SessionHandle *data = conn->data;
struct ssl_connect_data *connssl = &conn->ssl[sockindex];
bool done = FALSE;
SecBuffer inbuf[4];
SecBufferDesc inbuf_desc;
SECURITY_STATUS sspi_status = SEC_E_OK;
infof(data, "schannel: client wants to read %d\n", len);
*err = CURLE_OK;
/* buffer to store previously received and decrypted data */
if(connssl->decdata_buffer == NULL) {
connssl->decdata_offset = 0;
connssl->decdata_length = 4096;
connssl->decdata_buffer = malloc(connssl->decdata_length);
if(connssl->decdata_buffer == NULL) {
failf(data, "schannel: unable to allocate memory");
return CURLE_OUT_OF_MEMORY;
}
}
/* increase buffers in order to fit the requested amount of data */
while(connssl->encdata_length - connssl->encdata_offset < 2048 ||
connssl->encdata_length < len) {
/* increase internal encrypted data buffer */
connssl->encdata_length += 2048;
connssl->encdata_buffer = realloc(connssl->encdata_buffer,
connssl->encdata_length);
if(connssl->encdata_buffer == NULL) {
failf(data, "schannel: unable to re-allocate memory");
*err = CURLE_OUT_OF_MEMORY;
return -1;
}
/* increase internal decrypted data buffer */
connssl->decdata_length += 2048;
connssl->decdata_buffer = realloc(connssl->decdata_buffer,
connssl->decdata_length);
if(connssl->decdata_buffer == NULL) {
failf(data, "schannel: unable to re-allocate memory");
*err = CURLE_OUT_OF_MEMORY;
return -1;
}
}
/* read encrypted data from socket */
infof(data, "schannel: encrypted data buffer %d/%d\n",
connssl->encdata_offset, connssl->encdata_length);
size = connssl->encdata_length - connssl->encdata_offset;
if(size > 0) {
read = sread(conn->sock[sockindex],
connssl->encdata_buffer + connssl->encdata_offset, size);
infof(data, "schannel: encrypted data received %d\n", read);
/* check for received data */
if(read > 0) {
/* increase encrypted data buffer offset */
connssl->encdata_offset += read;
}
else if(connssl->encdata_offset == 0) {
if(read == 0)
ret = 0;
else
*err = CURLE_AGAIN;
}
}
infof(data, "schannel: encrypted data buffer %d/%d\n",
connssl->encdata_offset, connssl->encdata_length);
/* check if we still have some data in our buffers */
while(connssl->encdata_offset > 0 && sspi_status == SEC_E_OK) {
/* prepare data buffer for DecryptMessage call */
inbuf[0].pvBuffer = connssl->encdata_buffer;
inbuf[0].cbBuffer = connssl->encdata_offset;
inbuf[0].BufferType = SECBUFFER_DATA;
/* we need 3 more empty input buffers for possible output */
inbuf[1].pvBuffer = NULL;
inbuf[1].cbBuffer = 0;
inbuf[1].BufferType = SECBUFFER_EMPTY;
inbuf[2].pvBuffer = NULL;
inbuf[2].cbBuffer = 0;
inbuf[2].BufferType = SECBUFFER_EMPTY;
inbuf[3].pvBuffer = NULL;
inbuf[3].cbBuffer = 0;
inbuf[3].BufferType = SECBUFFER_EMPTY;
inbuf_desc.pBuffers = &inbuf[0];
inbuf_desc.cBuffers = 4;
inbuf_desc.ulVersion = SECBUFFER_VERSION;
/* http://msdn.microsoft.com/en-us/library/windows/desktop/aa375348.aspx */
sspi_status = s_pSecFn->DecryptMessage(&connssl->ctxt->ctxt_handle,
&inbuf_desc, 0, NULL);
infof(data, "schannel: DecryptMessage %d\n", sspi_status);
/* check if everything went fine (server may want to renegotiate context) */
if(sspi_status == SEC_E_OK || sspi_status == SEC_I_RENEGOTIATE) {
/* check for successfully decrypted data */
if(inbuf[1].BufferType == SECBUFFER_DATA) {
infof(data, "schannel: decrypted data length: %d\n", inbuf[1].cbBuffer);
/* copy decrypted data to internal buffer */
size = connssl->decdata_length - connssl->decdata_offset;
size = size < inbuf[1].cbBuffer ? size : inbuf[1].cbBuffer;
if(size > 0) {
memcpy(connssl->decdata_buffer + connssl->decdata_offset,
inbuf[1].pvBuffer, size);
connssl->decdata_offset += size;
}
infof(data, "schannel: decrypted data added: %d\n", size);
infof(data, "schannel: decrypted data cached: %d/%d\n",
connssl->decdata_offset, connssl->decdata_length);
}
/* check for remaining encrypted data */
if(inbuf[3].BufferType = SECBUFFER_EXTRA) {
infof(data, "schannel: encrypted data length: %d\n", inbuf[3].cbBuffer);
/* check if the remaining data is less than the total amount
* and therefore begins after the already processed data
*/
if(connssl->encdata_offset > inbuf[3].cbBuffer) {
/* move remaining encrypted data forward to the beginning of buffer */
memmove(connssl->encdata_buffer,
(connssl->encdata_buffer + connssl->encdata_offset) -
inbuf[3].cbBuffer, inbuf[3].cbBuffer);
connssl->encdata_offset = inbuf[3].cbBuffer;
}
infof(data, "schannel: encrypted data cached: %d/%d\n",
connssl->encdata_offset, connssl->encdata_length);
}
else{
/* reset encrypted buffer offset, because there is no data remaining */
connssl->encdata_offset = 0;
}
}
/* check if server wants to renegotiate the connection context */
if(sspi_status == SEC_I_RENEGOTIATE) {
infof(data, "schannel: client needs to renegotiate with server\n");
/* begin renegotiation */
connssl->state = ssl_connection_negotiating;
connssl->connecting_state = ssl_connect_2_writing;
retcode = schannel_connect_common(conn, sockindex, FALSE, &done);
if(retcode)
*err = retcode;
else /* now retry receiving data */
return schannel_recv(conn, sockindex, buf, len, err);
}
}
/* copy requested decrypted data to supplied buffer */
size = len < connssl->decdata_offset ? len : connssl->decdata_offset;
if(size > 0) {
memcpy(buf, connssl->decdata_buffer, size);
ret = size;
/* move remaining decrypted data forward to the beginning of buffer */
memmove(connssl->decdata_buffer, connssl->decdata_buffer + size,
connssl->decdata_offset - size);
connssl->decdata_offset -= size;
}
/* reduce internal buffer length to reduce memory usage */
if(connssl->encdata_length > 4096) {
connssl->encdata_length = connssl->encdata_offset > 0 ?
connssl->encdata_offset + 2048 : 4096;
connssl->encdata_buffer = realloc(connssl->encdata_buffer,
connssl->encdata_length);
}
if(connssl->decdata_length > 4096) {
connssl->decdata_length = connssl->decdata_offset > 0 ?
connssl->decdata_offset + 2048 : 4096;
connssl->decdata_buffer = realloc(connssl->decdata_buffer,
connssl->decdata_length);
}
/* check if the server closed the connection */
if(ret <= 0 && sspi_status == SEC_I_CONTEXT_EXPIRED) {
infof(data, "schannel: server closed the connection\n");
*err = CURLE_OK;
return 0;
}
/* check if something went wrong and we need to return an error */
if(ret < 0) {
if(sspi_status == SEC_E_INCOMPLETE_MESSAGE)
*err = CURLE_AGAIN;
else if(sspi_status != SEC_E_OK)
*err = CURLE_RECV_ERROR;
return -1;
}
/* everything went fine */
infof(data, "schannel: read returns %d with error code %d\n", ret, *err);
return ret;
}
CURLcode
Curl_schannel_connect_nonblocking(struct connectdata *conn, int sockindex,
bool *done) {
return schannel_connect_common(conn, sockindex, TRUE, done);
}
CURLcode
Curl_schannel_connect(struct connectdata *conn, int sockindex) {
CURLcode retcode;
bool done = FALSE;
retcode = schannel_connect_common(conn, sockindex, FALSE, &done);
if(retcode)
return retcode;
DEBUGASSERT(done);
return CURLE_OK;
}
bool Curl_schannel_data_pending(const struct connectdata *conn, int sockindex) {
const struct ssl_connect_data *connssl = &conn->ssl[sockindex];
if(connssl->use) /* SSL is in use */
return (connssl->encdata_offset > 0 ||
connssl->decdata_offset > 0 ) ? TRUE : FALSE;
else
return FALSE;
}
void Curl_schannel_close(struct connectdata *conn, int sockindex) {
struct SessionHandle *data = conn->data;
struct ssl_connect_data *connssl = &conn->ssl[sockindex];
infof(data, "schannel: Closing connection with %s:%d\n",
conn->host.name, conn->remote_port);
/* free SSPI Schannel API security context handle */
if(connssl->ctxt) {
s_pSecFn->DeleteSecurityContext(&connssl->ctxt->ctxt_handle);
free(connssl->ctxt);
connssl->ctxt = NULL;
}
/* free internal buffer for received encrypted data */
if(connssl->encdata_buffer != NULL) {
free(connssl->encdata_buffer);
connssl->encdata_buffer = NULL;
connssl->encdata_length = 0;
connssl->encdata_offset = 0;
}
/* free internal buffer for received decrypted data */
if(connssl->decdata_buffer != NULL) {
free(connssl->decdata_buffer);
connssl->decdata_buffer = NULL;
connssl->decdata_length = 0;
connssl->decdata_offset = 0;
}
}
int Curl_schannel_shutdown(struct connectdata *conn, int sockindex) {
return CURLE_NOT_BUILT_IN; /* TODO: implement SSL/TLS shutdown */
}
void Curl_schannel_session_free(void *ptr) {
curl_schannel_cred *cred = ptr;
if(cred) {
s_pSecFn->FreeCredentialsHandle(&cred->cred_handle);
free(cred);
}
}
int Curl_schannel_init() {
return (Curl_sspi_global_init() == CURLE_OK ? 1 : 0);
}
void Curl_schannel_cleanup() {
Curl_sspi_global_cleanup();
}
size_t Curl_schannel_version(char *buffer, size_t size)
{
unsigned long version = s_pSecFn ? s_pSecFn->dwVersion : 0;
return snprintf(buffer, size, "Schannel/%d.%d.%d.%d",
(version>>0)&0xff, (version>>8)&0xff,
(version>>16)&0xff, (version>>24)&0xff);
}
#endif /* USE_SCHANNEL */
#endif /* USE_WINDOWS_SSPI */
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