/**

 * WinPR: Windows Portable Runtime

 * Schannel Security Package (OpenSSL)

 *

 * Copyright 2012-2014 Marc-Andre Moreau <marcandre.moreau@gmail.com>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <winpr/config.h>

#include "schannel_openssl.h"

#ifdef WITH_OPENSSL

#include <winpr/crt.h>

#include <winpr/sspi.h>

#include <winpr/ssl.h>

#include <winpr/print.h>

#include <winpr/crypto.h>

#include <openssl/ssl.h>

#include <openssl/err.h>

#include <openssl/bio.h>

#define LIMIT_INTMAX(a) ((a) > INT32_MAX) ? INT32_MAX : (int)(a)

struct S_SCHANNEL_OPENSSL

{

  SSL* ssl;

  SSL_CTX* ctx;

  BOOL connected;

  BIO* bioRead;

  BIO* bioWrite;

  BYTE* ReadBuffer;

  BYTE* WriteBuffer;

};

#include "../../log.h"

#define TAG WINPR_TAG("sspi.schannel")

static char* openssl_get_ssl_error_string(int ssl_error)

{

  switch (ssl_error)

  {

    case SSL_ERROR_ZERO_RETURN:

      return "SSL_ERROR_ZERO_RETURN";

    case SSL_ERROR_WANT_READ:

      return "SSL_ERROR_WANT_READ";

    case SSL_ERROR_WANT_WRITE:

      return "SSL_ERROR_WANT_WRITE";

    case SSL_ERROR_SYSCALL:

      return "SSL_ERROR_SYSCALL";

    case SSL_ERROR_SSL:

      return "SSL_ERROR_SSL";

    default:

      break;

  }

  return "SSL_ERROR_UNKNOWN";

}

static void schannel_context_cleanup(SCHANNEL_OPENSSL* context)

{

  WINPR_ASSERT(context);

  free(context->ReadBuffer);

  context->ReadBuffer = nullptr;

  if (context->bioWrite)

    BIO_free_all(context->bioWrite);

  context->bioWrite = nullptr;

  if (context->bioRead)

    BIO_free_all(context->bioRead);

  context->bioRead = nullptr;

  if (context->ssl)

    SSL_free(context->ssl);

  context->ssl = nullptr;

  if (context->ctx)

    SSL_CTX_free(context->ctx);

  context->ctx = nullptr;

}

static const SSL_METHOD* get_method(BOOL server)

{

  if (server)

  {

#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)

    return SSLv23_server_method();

#else

    return TLS_server_method();

#endif

  }

  else

  {

#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)

    return SSLv23_client_method();

#else

    return TLS_client_method();

#endif

  }

}

int schannel_openssl_client_init(SCHANNEL_OPENSSL* context)

{

  int status = 0;

  long options = 0;

  context->ctx = SSL_CTX_new(get_method(FALSE));

  if (!context->ctx)

  {

    WLog_ERR(TAG, "SSL_CTX_new failed");

    return -1;

  }

  /**

   * SSL_OP_NO_COMPRESSION:

   *

   * The Microsoft RDP server does not advertise support

   * for TLS compression, but alternative servers may support it.

   * This was observed between early versions of the FreeRDP server

   * and the FreeRDP client, and caused major performance issues,

   * which is why we're disabling it.

   */

#ifdef SSL_OP_NO_COMPRESSION

  options |= SSL_OP_NO_COMPRESSION;

#endif

  /**

   * SSL_OP_TLS_BLOCK_PADDING_BUG:

   *

   * The Microsoft RDP server does *not* support TLS padding.

   * It absolutely needs to be disabled otherwise it won't work.

   */

  options |= SSL_OP_TLS_BLOCK_PADDING_BUG;

  /**

   * SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS:

   *

   * Just like TLS padding, the Microsoft RDP server does not

   * support empty fragments. This needs to be disabled.

   */

  options |= SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;

  SSL_CTX_set_options(context->ctx, WINPR_ASSERTING_INT_CAST(uint64_t, options));

  context->ssl = SSL_new(context->ctx);

  if (!context->ssl)

  {

    WLog_ERR(TAG, "SSL_new failed");

    goto fail;

  }

  context->bioRead = BIO_new(BIO_s_mem());

  if (!context->bioRead)

  {

    WLog_ERR(TAG, "BIO_new failed");

    goto fail;

  }

  status = BIO_set_write_buf_size(context->bioRead, SCHANNEL_CB_MAX_TOKEN);

  if (status != 1)

  {

    WLog_ERR(TAG, "BIO_set_write_buf_size on bioRead failed");

    goto fail;

  }

  context->bioWrite = BIO_new(BIO_s_mem());

  if (!context->bioWrite)

  {

    WLog_ERR(TAG, "BIO_new failed");

    goto fail;

  }

  status = BIO_set_write_buf_size(context->bioWrite, SCHANNEL_CB_MAX_TOKEN);

  if (status != 1)

  {

    WLog_ERR(TAG, "BIO_set_write_buf_size on bioWrite failed");

    goto fail;

  }

  status = BIO_make_bio_pair(context->bioRead, context->bioWrite);

  if (status != 1)

  {

    WLog_ERR(TAG, "BIO_make_bio_pair failed");

    goto fail;

  }

  SSL_set_bio(context->ssl, context->bioRead, context->bioWrite);

  context->ReadBuffer = (BYTE*)malloc(SCHANNEL_CB_MAX_TOKEN);

  if (!context->ReadBuffer)

  {

    WLog_ERR(TAG, "Failed to allocate ReadBuffer");

    goto fail;

  }

  context->WriteBuffer = (BYTE*)malloc(SCHANNEL_CB_MAX_TOKEN);

  if (!context->WriteBuffer)

  {

    WLog_ERR(TAG, "Failed to allocate ReadBuffer");

    goto fail;

  }

  return 0;

fail:

  schannel_context_cleanup(context);

  return -1;

}

int schannel_openssl_server_init(SCHANNEL_OPENSSL* context)

{

  int status = 0;

  unsigned long options = 0;

  context->ctx = SSL_CTX_new(get_method(TRUE));

  if (!context->ctx)

  {

    WLog_ERR(TAG, "SSL_CTX_new failed");

    return -1;

  }

  /*

   * SSL_OP_NO_SSLv2:

   *

   * We only want SSLv3 and TLSv1, so disable SSLv2.

   * SSLv3 is used by, eg. Microsoft RDC for Mac OS X.

   */

  options |= SSL_OP_NO_SSLv2;

  /**

   * SSL_OP_NO_COMPRESSION:

   *

   * The Microsoft RDP server does not advertise support

   * for TLS compression, but alternative servers may support it.

   * This was observed between early versions of the FreeRDP server

   * and the FreeRDP client, and caused major performance issues,

   * which is why we're disabling it.

   */

#ifdef SSL_OP_NO_COMPRESSION

  options |= SSL_OP_NO_COMPRESSION;

#endif

  /**

   * SSL_OP_TLS_BLOCK_PADDING_BUG:

   *

   * The Microsoft RDP server does *not* support TLS padding.

   * It absolutely needs to be disabled otherwise it won't work.

   */

  options |= SSL_OP_TLS_BLOCK_PADDING_BUG;

  /**

   * SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS:

   *

   * Just like TLS padding, the Microsoft RDP server does not

   * support empty fragments. This needs to be disabled.

   */

  options |= SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;

  SSL_CTX_set_options(context->ctx, options);

#if defined(WITH_DEBUG_SCHANNEL)

  {

    const char* key = getenv("FREERDP_SCHANNEL_KEY");

    if (!key)

      key = "/tmp/localhost.key";

    if (SSL_CTX_use_PrivateKey_file(context->ctx, key, SSL_FILETYPE_PEM) <= 0)

    {

      WLog_ERR(TAG, "SSL_CTX_use_RSAPrivateKey_file failed");

      goto fail;

    }

  }

#endif

  context->ssl = SSL_new(context->ctx);

  if (!context->ssl)

  {

    WLog_ERR(TAG, "SSL_new failed");

    goto fail;

  }

  if (SSL_use_certificate_file(context->ssl, "/tmp/localhost.crt", SSL_FILETYPE_PEM) <= 0)

  {

    WLog_ERR(TAG, "SSL_use_certificate_file failed");

    goto fail;

  }

  context->bioRead = BIO_new(BIO_s_mem());

  if (!context->bioRead)

  {

    WLog_ERR(TAG, "BIO_new failed");

    goto fail;

  }

  status = BIO_set_write_buf_size(context->bioRead, SCHANNEL_CB_MAX_TOKEN);

  if (status != 1)

  {

    WLog_ERR(TAG, "BIO_set_write_buf_size failed for bioRead");

    goto fail;

  }

  context->bioWrite = BIO_new(BIO_s_mem());

  if (!context->bioWrite)

  {

    WLog_ERR(TAG, "BIO_new failed");

    goto fail;

  }

  status = BIO_set_write_buf_size(context->bioWrite, SCHANNEL_CB_MAX_TOKEN);

  if (status != 1)

  {

    WLog_ERR(TAG, "BIO_set_write_buf_size failed for bioWrite");

    goto fail;

  }

  status = BIO_make_bio_pair(context->bioRead, context->bioWrite);

  if (status != 1)

  {

    WLog_ERR(TAG, "BIO_make_bio_pair failed");

    goto fail;

  }

  SSL_set_bio(context->ssl, context->bioRead, context->bioWrite);

  context->ReadBuffer = (BYTE*)malloc(SCHANNEL_CB_MAX_TOKEN);

  if (!context->ReadBuffer)

  {

    WLog_ERR(TAG, "Failed to allocate memory for ReadBuffer");

    goto fail;

  }

  context->WriteBuffer = (BYTE*)malloc(SCHANNEL_CB_MAX_TOKEN);

  if (!context->WriteBuffer)

  {

    WLog_ERR(TAG, "Failed to allocate memory for WriteBuffer");

    goto fail;

  }

  return 0;

fail:

  schannel_context_cleanup(context);

  return -1;

}

SECURITY_STATUS schannel_openssl_client_process_tokens(SCHANNEL_OPENSSL* context,

                                                       PSecBufferDesc pInput,

                                                       PSecBufferDesc pOutput)

{

  int status = 0;

  int ssl_error = 0;

  PSecBuffer pBuffer = nullptr;

  if (!context->connected)

  {

    if (pInput)

    {

      if (pInput->cBuffers < 1)

        return SEC_E_INVALID_TOKEN;

      pBuffer = sspi_FindSecBuffer(pInput, SECBUFFER_TOKEN);

      if (!pBuffer)

        return SEC_E_INVALID_TOKEN;

      ERR_clear_error();

      status =

          BIO_write(context->bioRead, pBuffer->pvBuffer, LIMIT_INTMAX(pBuffer->cbBuffer));

      if (status < 0)

        return SEC_E_INVALID_TOKEN;

    }

    status = SSL_connect(context->ssl);

    if (status < 0)

    {

      ssl_error = SSL_get_error(context->ssl, status);

      WLog_ERR(TAG, "SSL_connect error: %s", openssl_get_ssl_error_string(ssl_error));

    }

    if (status == 1)

      context->connected = TRUE;

    ERR_clear_error();

    status = BIO_read(context->bioWrite, context->ReadBuffer, SCHANNEL_CB_MAX_TOKEN);

    if (pOutput->cBuffers < 1)

      return SEC_E_INVALID_TOKEN;

    pBuffer = sspi_FindSecBuffer(pOutput, SECBUFFER_TOKEN);

    if (!pBuffer)

      return SEC_E_INVALID_TOKEN;

    if (status > 0)

    {

      if (pBuffer->cbBuffer < WINPR_ASSERTING_INT_CAST(uint32_t, status))

        return SEC_E_INSUFFICIENT_MEMORY;

      CopyMemory(pBuffer->pvBuffer, context->ReadBuffer,

                 WINPR_ASSERTING_INT_CAST(uint32_t, status));

      pBuffer->cbBuffer = WINPR_ASSERTING_INT_CAST(uint32_t, status);

      return (context->connected) ? SEC_E_OK : SEC_I_CONTINUE_NEEDED;

    }

    else

    {

      pBuffer->cbBuffer = 0;

      return (context->connected) ? SEC_E_OK : SEC_I_CONTINUE_NEEDED;

    }

  }

  return SEC_E_OK;

}

SECURITY_STATUS schannel_openssl_server_process_tokens(SCHANNEL_OPENSSL* context,

                                                       PSecBufferDesc pInput,

                                                       PSecBufferDesc pOutput)

{

  int status = 0;

  int ssl_error = 0;

  PSecBuffer pBuffer = nullptr;

  if (!context->connected)

  {

    if (pInput->cBuffers < 1)

      return SEC_E_INVALID_TOKEN;

    pBuffer = sspi_FindSecBuffer(pInput, SECBUFFER_TOKEN);

    if (!pBuffer)

      return SEC_E_INVALID_TOKEN;

    ERR_clear_error();

    status = BIO_write(context->bioRead, pBuffer->pvBuffer, LIMIT_INTMAX(pBuffer->cbBuffer));

    if (status >= 0)

      status = SSL_accept(context->ssl);

    if (status < 0)

    {

      ssl_error = SSL_get_error(context->ssl, status);

      WLog_ERR(TAG, "SSL_accept error: %s", openssl_get_ssl_error_string(ssl_error));

      return SEC_E_INVALID_TOKEN;

    }

    if (status == 1)

      context->connected = TRUE;

    ERR_clear_error();

    status = BIO_read(context->bioWrite, context->ReadBuffer, SCHANNEL_CB_MAX_TOKEN);

    if (status < 0)

    {

      ssl_error = SSL_get_error(context->ssl, status);

      WLog_ERR(TAG, "BIO_read: %s", openssl_get_ssl_error_string(ssl_error));

      return SEC_E_INVALID_TOKEN;

    }

    if (pOutput->cBuffers < 1)

      return SEC_E_INVALID_TOKEN;

    pBuffer = sspi_FindSecBuffer(pOutput, SECBUFFER_TOKEN);

    if (!pBuffer)

      return SEC_E_INVALID_TOKEN;

    if (status > 0)

    {

      if (pBuffer->cbBuffer < WINPR_ASSERTING_INT_CAST(uint32_t, status))

        return SEC_E_INSUFFICIENT_MEMORY;

      CopyMemory(pBuffer->pvBuffer, context->ReadBuffer,

                 WINPR_ASSERTING_INT_CAST(uint32_t, status));

      pBuffer->cbBuffer = WINPR_ASSERTING_INT_CAST(uint32_t, status);

      return (context->connected) ? SEC_E_OK : SEC_I_CONTINUE_NEEDED;

    }

    else

    {

      pBuffer->cbBuffer = 0;

      return (context->connected) ? SEC_E_OK : SEC_I_CONTINUE_NEEDED;

    }

  }

  return SEC_E_OK;

}

SECURITY_STATUS schannel_openssl_encrypt_message(SCHANNEL_OPENSSL* context, PSecBufferDesc pMessage)

{

  int status = 0;

  int ssl_error = 0;

  PSecBuffer pStreamBodyBuffer = nullptr;

  PSecBuffer pStreamHeaderBuffer = nullptr;

  PSecBuffer pStreamTrailerBuffer = nullptr;

  pStreamHeaderBuffer = sspi_FindSecBuffer(pMessage, SECBUFFER_STREAM_HEADER);

  pStreamBodyBuffer = sspi_FindSecBuffer(pMessage, SECBUFFER_DATA);

  pStreamTrailerBuffer = sspi_FindSecBuffer(pMessage, SECBUFFER_STREAM_TRAILER);

  if ((!pStreamHeaderBuffer) || (!pStreamBodyBuffer) || (!pStreamTrailerBuffer))

    return SEC_E_INVALID_TOKEN;

  status = SSL_write(context->ssl, pStreamBodyBuffer->pvBuffer,

                     LIMIT_INTMAX(pStreamBodyBuffer->cbBuffer));

  if (status < 0)

  {

    ssl_error = SSL_get_error(context->ssl, status);

    WLog_ERR(TAG, "SSL_write: %s", openssl_get_ssl_error_string(ssl_error));

  }

  ERR_clear_error();

  status = BIO_read(context->bioWrite, context->ReadBuffer, SCHANNEL_CB_MAX_TOKEN);

  if (status > 0)

  {

    size_t ustatus = (size_t)status;

    size_t length = 0;

    size_t offset = 0;

    length =

        (pStreamHeaderBuffer->cbBuffer > ustatus) ? ustatus : pStreamHeaderBuffer->cbBuffer;

    CopyMemory(pStreamHeaderBuffer->pvBuffer, &context->ReadBuffer[offset], length);

    ustatus -= length;

    offset += length;

    length = (pStreamBodyBuffer->cbBuffer > ustatus) ? ustatus : pStreamBodyBuffer->cbBuffer;

    CopyMemory(pStreamBodyBuffer->pvBuffer, &context->ReadBuffer[offset], length);

    ustatus -= length;

    offset += length;

    length =

        (pStreamTrailerBuffer->cbBuffer > ustatus) ? ustatus : pStreamTrailerBuffer->cbBuffer;

    CopyMemory(pStreamTrailerBuffer->pvBuffer, &context->ReadBuffer[offset], length);

  }

  return SEC_E_OK;

}

SECURITY_STATUS schannel_openssl_decrypt_message(SCHANNEL_OPENSSL* context, PSecBufferDesc pMessage)

{

  int status = 0;

  int length = 0;

  BYTE* buffer = nullptr;

  int ssl_error = 0;

  PSecBuffer pBuffer = nullptr;

  pBuffer = sspi_FindSecBuffer(pMessage, SECBUFFER_DATA);

  if (!pBuffer)

    return SEC_E_INVALID_TOKEN;

  ERR_clear_error();

  status = BIO_write(context->bioRead, pBuffer->pvBuffer, LIMIT_INTMAX(pBuffer->cbBuffer));

  if (status > 0)

    status = SSL_read(context->ssl, pBuffer->pvBuffer, LIMIT_INTMAX(pBuffer->cbBuffer));

  if (status < 0)

  {

    ssl_error = SSL_get_error(context->ssl, status);

    WLog_ERR(TAG, "SSL_read: %s", openssl_get_ssl_error_string(ssl_error));

  }

  length = status;

  buffer = pBuffer->pvBuffer;

  pMessage->pBuffers[0].BufferType = SECBUFFER_STREAM_HEADER;

  pMessage->pBuffers[0].cbBuffer = 5;

  pMessage->pBuffers[1].BufferType = SECBUFFER_DATA;

  pMessage->pBuffers[1].pvBuffer = buffer;

  pMessage->pBuffers[1].cbBuffer = WINPR_ASSERTING_INT_CAST(uint32_t, length);

  pMessage->pBuffers[2].BufferType = SECBUFFER_STREAM_TRAILER;

  pMessage->pBuffers[2].cbBuffer = 36;

  pMessage->pBuffers[3].BufferType = SECBUFFER_EMPTY;

  pMessage->pBuffers[3].cbBuffer = 0;

  return SEC_E_OK;

}

SCHANNEL_OPENSSL* schannel_openssl_new(void)

{

  if (!winpr_InitializeSSL(WINPR_SSL_INIT_DEFAULT))

    return nullptr;

  SCHANNEL_OPENSSL* context = (SCHANNEL_OPENSSL*)calloc(1, sizeof(SCHANNEL_OPENSSL));

  if (context != nullptr)

  {

    context->connected = FALSE;

  }

  return context;

}

void schannel_openssl_free(SCHANNEL_OPENSSL* context)

{

  if (context)

  {

    free(context->ReadBuffer);

    free(context->WriteBuffer);

    free(context);

  }

}

#else

int schannel_openssl_client_init(SCHANNEL_OPENSSL* context)

{

  return 0;

}

int schannel_openssl_server_init(SCHANNEL_OPENSSL* context)

{

  return 0;

}

SECURITY_STATUS schannel_openssl_client_process_tokens(SCHANNEL_OPENSSL* context,

                                                       PSecBufferDesc pInput,

                                                       PSecBufferDesc pOutput)

{

  return SEC_E_OK;

}

SECURITY_STATUS schannel_openssl_server_process_tokens(SCHANNEL_OPENSSL* context,

                                                       PSecBufferDesc pInput,

                                                       PSecBufferDesc pOutput)

{

  return SEC_E_OK;

}

SECURITY_STATUS schannel_openssl_encrypt_message(SCHANNEL_OPENSSL* context, PSecBufferDesc pMessage)

{

  return SEC_E_OK;

}

SECURITY_STATUS schannel_openssl_decrypt_message(SCHANNEL_OPENSSL* context, PSecBufferDesc pMessage)

{

  return SEC_E_OK;

}

SCHANNEL_OPENSSL* schannel_openssl_new(void)

{

  return nullptr;

}

void schannel_openssl_free(SCHANNEL_OPENSSL* context)

{

}

#endif