source: lib/ssl_sspi.c @ 18da20b

  /********************************************************************\
  * BitlBee -- An IRC to other IM-networks gateway                     *
  *                                                                    *
  * Copyright 2002-2004 Wilmer van der Gaast and others                *
  \********************************************************************/

/* SSL module - SSPI backend */

/* Copyright (C) 2005 Jelmer Vernooij <jelmer@samba.org> */

/*
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License with
  the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
  if not, write to the Free Software Foundation, Inc., 59 Temple Place,
  Suite 330, Boston, MA  02111-1307  USA
*/

#include "ssl_client.h"
#include <windows.h>
#define SECURITY_WIN32
#include <security.h>
#include <sspi.h>
#include <schannel.h>
#include "sock.h"

static gboolean initialized = FALSE;
int ssl_errno;

struct scd
{
        int fd;
        ssl_input_function func;
        gpointer data;
        gboolean established;
        CredHandle cred;                /* SSL credentials */
        CtxtHandle context;             /* SSL context */
        SecPkgContext_StreamSizes sizes;

        char *host;

        char *pending_raw_data;
        gsize pending_raw_data_len;
        char *pending_data;
        gsize pending_data_len;
};

static void ssl_connected(gpointer, gint, GaimInputCondition);

void sspi_global_init(void)
{
        /* FIXME */
}

void sspi_global_deinit(void)
{
        /* FIXME */
}

void *ssl_connect(char *host, int port, ssl_input_function func, gpointer data)
{
        struct scd *conn = g_new0(struct scd, 1);
                
        conn->fd = proxy_connect(host, port, ssl_connected, conn);
        sock_make_nonblocking(conn->fd);
        conn->func = func;
        conn->data = data;
        conn->host = g_strdup(host);
        
        if (conn->fd < 0)
        {
                g_free(conn);
                return NULL;
        }
        
        if (!initialized)
        {
                sspi_global_init();
                initialized = TRUE;
                atexit(sspi_global_deinit);
        }

        return conn;
}

static void ssl_connected(gpointer _conn, gint fd, GaimInputCondition cond)
{
        struct scd *conn = _conn;
        SCHANNEL_CRED ssl_cred;
        TimeStamp timestamp;
        SecBuffer ibuf[2],obuf[1];
        SecBufferDesc ibufs,obufs;
        ULONG req = ISC_REQ_REPLAY_DETECT | ISC_REQ_SEQUENCE_DETECT |
        ISC_REQ_CONFIDENTIALITY | ISC_REQ_USE_SESSION_KEY |
        ISC_REQ_ALLOCATE_MEMORY | ISC_REQ_STREAM | ISC_REQ_EXTENDED_ERROR |
                ISC_REQ_MANUAL_CRED_VALIDATION;
        ULONG a;
        gsize size = 0;
        gchar *data = NULL;

        memset(&ssl_cred, 0, sizeof(SCHANNEL_CRED));
        ssl_cred.dwVersion = SCHANNEL_CRED_VERSION;
        ssl_cred.grbitEnabledProtocols = SP_PROT_SSL3_CLIENT;

        SECURITY_STATUS st = AcquireCredentialsHandle(NULL, UNISP_NAME, SECPKG_CRED_OUTBOUND, NULL, &ssl_cred, NULL, NULL, &conn->cred, &timestamp);

        if (st != SEC_E_OK) {
                conn->func(conn->data, NULL, cond);
                return;
        }
        
        do {
                /* initialize buffers */
            ibuf[0].cbBuffer = size; ibuf[0].pvBuffer = data;
            ibuf[1].cbBuffer = 0; ibuf[1].pvBuffer = NULL;
            obuf[0].cbBuffer = 0; obuf[0].pvBuffer = NULL;
        ibuf[0].BufferType = obuf[0].BufferType = SECBUFFER_TOKEN;
            ibuf[1].BufferType = SECBUFFER_EMPTY;

                /* initialize buffer descriptors */
            ibufs.ulVersion = obufs.ulVersion = SECBUFFER_VERSION;
            ibufs.cBuffers = 2; obufs.cBuffers = 1;
            ibufs.pBuffers = ibuf; obufs.pBuffers = obuf;

                st = InitializeSecurityContext(&conn->cred, size?&conn->context:NULL, conn->host, req, 0, SECURITY_NETWORK_DREP, size?&ibufs:NULL, 0, &conn->context, &obufs, &a, &timestamp);  
        if (obuf[0].pvBuffer && obuf[0].cbBuffer) {
                        /* FIXME: Check return value */
                        send(conn->fd, obuf[0].pvBuffer, obuf[0].cbBuffer, 0);
                }

                switch (st) {
                case SEC_I_INCOMPLETE_CREDENTIALS:
                        break;
                case SEC_I_CONTINUE_NEEDED:
                        break;
                case SEC_E_INCOMPLETE_MESSAGE:
                        break;
                case SEC_E_OK:
                        break;
                }
        
                QueryContextAttributes(&conn->context, SECPKG_ATTR_STREAM_SIZES, &conn->sizes);
        } while (1);

        conn->func(conn->data, conn, cond);
}

int ssl_read(void *conn, char *retdata, int len)
{
        struct scd *scd = conn;
        SecBufferDesc msg;
        SecBuffer buf[4];
        int ret = -1, i;
        char *data = g_malloc(scd->sizes.cbHeader + scd->sizes.cbMaximumMessage + scd->sizes.cbTrailer);

        /* FIXME: Try to read some data */

        msg.ulVersion = SECBUFFER_VERSION;
        msg.cBuffers = 4;
        msg.pBuffers = buf;
        
        buf[0].BufferType = SECBUFFER_DATA;
        buf[0].cbBuffer = len;
        buf[0].pvBuffer = data;

        buf[1].BufferType = SECBUFFER_EMPTY;
        buf[2].BufferType = SECBUFFER_EMPTY;
        buf[3].BufferType = SECBUFFER_EMPTY;

        SECURITY_STATUS st = DecryptMessage(&scd->context, &msg, 0, NULL);

        if (st != SEC_E_OK) {
                /* FIXME */
                return -1;
        }

        for (i = 0; i < 4; i++) {
                if (buf[i].BufferType == SECBUFFER_DATA) {
                        memcpy(retdata, buf[i].pvBuffer, len);
                        ret = len;
                }       
        }

        g_free(data);
        return -1;
}

int ssl_write(void *conn, const char *userdata, int len)
{
        struct scd *scd = conn;
        SecBuffer buf[4];
        SecBufferDesc msg;
        char *data;
        int ret;

        msg.ulVersion = SECBUFFER_VERSION;
        msg.cBuffers = 4;
        msg.pBuffers = buf;

        data = g_malloc(scd->sizes.cbHeader + scd->sizes.cbMaximumMessage + scd->sizes.cbTrailer);
        memcpy(data + scd->sizes.cbHeader, userdata, len);

        buf[0].BufferType = SECBUFFER_STREAM_HEADER;
        buf[0].cbBuffer = scd->sizes.cbHeader;
        buf[0].pvBuffer = data;

        buf[1].BufferType = SECBUFFER_DATA;
        buf[1].cbBuffer = len;
        buf[1].pvBuffer = data + scd->sizes.cbHeader;

        buf[2].BufferType = SECBUFFER_STREAM_TRAILER;
        buf[2].cbBuffer = scd->sizes.cbTrailer;
        buf[2].pvBuffer = data + scd->sizes.cbHeader + len;
        buf[3].BufferType = SECBUFFER_EMPTY;

        SECURITY_STATUS st = EncryptMessage(&scd->context, 0, &msg, 0);

        ret = send(scd->fd, data, 
                                buf[0].cbBuffer + buf[1].cbBuffer + buf[2].cbBuffer, 0);

        g_free(data);

        return ret;
}

void ssl_disconnect(void *conn)
{
        struct scd *scd = conn;

        SecBufferDesc msg;
        SecBuffer buf;
        DWORD dw;

        dw = SCHANNEL_SHUTDOWN;
        buf.cbBuffer = sizeof(dw);
        buf.BufferType = SECBUFFER_TOKEN;
        buf.pvBuffer = &dw;
        
        msg.ulVersion = SECBUFFER_VERSION;
        msg.cBuffers = 1;
        msg.pBuffers = &buf;

        SECURITY_STATUS st = ApplyControlToken(&scd->context, &msg);

        if (st != SEC_E_OK) {
                /* FIXME */
        }
        
        /* FIXME: call InitializeSecurityContext(Schannel), passing 
         * in empty buffers*/

        DeleteSecurityContext(&scd->context);

        FreeCredentialsHandle(&scd->cred);

        closesocket(scd->fd);
        g_free(scd->host);
        g_free(scd);
}

int ssl_getfd(void *conn)
{
        return ((struct scd*)conn)->fd;
}

GaimInputCondition ssl_getdirection( void *conn )
{
        return GAIM_INPUT_WRITE; /* FIXME: or GAIM_INPUT_READ */
}