/**

 * WinPR: Windows Portable Runtime

 * NTLM Security Package (Compute)

 *

 * Copyright 2011-2014 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 <winpr/assert.h>

#include "ntlm.h"

#include "../sspi.h"

#include <winpr/crt.h>

#include <winpr/sam.h>

#include <winpr/ntlm.h>

#include <winpr/print.h>

#include <winpr/crypto.h>

#include <winpr/sysinfo.h>

#include "ntlm_compute.h"

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

#define TAG WINPR_TAG("sspi.NTLM")

#define NTLM_CheckAndLogRequiredCapacity(tag, s, nmemb, what)                                    \

  Stream_CheckAndLogRequiredCapacityEx(tag, WLOG_WARN, s, nmemb, 1, "%s(%s:%" PRIuz ") " what, \

                                       __func__, __FILE__, (size_t)__LINE__)

static char NTLM_CLIENT_SIGN_MAGIC[] = "session key to client-to-server signing key magic constant";

static char NTLM_SERVER_SIGN_MAGIC[] = "session key to server-to-client signing key magic constant";

static char NTLM_CLIENT_SEAL_MAGIC[] = "session key to client-to-server sealing key magic constant";

static char NTLM_SERVER_SEAL_MAGIC[] = "session key to server-to-client sealing key magic constant";

static const BYTE NTLM_NULL_BUFFER[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

                                         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

/**

 * Populate VERSION structure msdn{cc236654}

 * @param versionInfo A pointer to the version struct

 *

 * @return \b TRUE for success, \b FALSE for failure

 */

BOOL ntlm_get_version_info(NTLM_VERSION_INFO* versionInfo)

{

  WINPR_ASSERT(versionInfo);

#if defined(WITH_WINPR_DEPRECATED)

  OSVERSIONINFOA osVersionInfo = WINPR_C_ARRAY_INIT;

  osVersionInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFOA);

  if (!GetVersionExA(&osVersionInfo))

    return FALSE;

  versionInfo->ProductMajorVersion = (UINT8)osVersionInfo.dwMajorVersion;

  versionInfo->ProductMinorVersion = (UINT8)osVersionInfo.dwMinorVersion;

  versionInfo->ProductBuild = (UINT16)osVersionInfo.dwBuildNumber;

#else

  /* Always return fixed version number.

   *

   * ProductVersion is fixed since windows 10 to Major 10, Minor 0

   * ProductBuild taken from https://en.wikipedia.org/wiki/Windows_11_version_history

   * with most recent (pre) release build number

   */

  versionInfo->ProductMajorVersion = 10;

  versionInfo->ProductMinorVersion = 0;

  versionInfo->ProductBuild = 22631;

#endif

  ZeroMemory(versionInfo->Reserved, sizeof(versionInfo->Reserved));

  versionInfo->NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;

  return TRUE;

}

/**

 * Read VERSION structure. msdn{cc236654}

 * @param s A pointer to a stream to read

 * @param versionInfo A pointer to the struct to read data to

 *

 * @return \b TRUE for success, \b FALSE for failure

 */

BOOL ntlm_read_version_info(wStream* s, NTLM_VERSION_INFO* versionInfo)

{

  WINPR_ASSERT(s);

  WINPR_ASSERT(versionInfo);

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 8))

    return FALSE;

  Stream_Read_UINT8(s, versionInfo->ProductMajorVersion); /* ProductMajorVersion (1 byte) */

  Stream_Read_UINT8(s, versionInfo->ProductMinorVersion); /* ProductMinorVersion (1 byte) */

  Stream_Read_UINT16(s, versionInfo->ProductBuild);       /* ProductBuild (2 bytes) */

  Stream_Read(s, versionInfo->Reserved, sizeof(versionInfo->Reserved)); /* Reserved (3 bytes) */

  Stream_Read_UINT8(s, versionInfo->NTLMRevisionCurrent); /* NTLMRevisionCurrent (1 byte) */

  return TRUE;

}

/**

 * Write VERSION structure. msdn{cc236654}

 * @param s A pointer to the stream to write to

 * @param versionInfo A pointer to the buffer to read the data from

 *

 * @return \b TRUE for success, \b FALSE for failure

 */

BOOL ntlm_write_version_info(wStream* s, const NTLM_VERSION_INFO* versionInfo)

{

  WINPR_ASSERT(s);

  WINPR_ASSERT(versionInfo);

  if (!Stream_CheckAndLogRequiredCapacityEx(

          TAG, WLOG_WARN, s, 5ull + sizeof(versionInfo->Reserved), 1ull,

          "%s(%s:%" PRIuz ") NTLM_VERSION_INFO", __func__, __FILE__, (size_t)__LINE__))

    return FALSE;

  Stream_Write_UINT8(s, versionInfo->ProductMajorVersion); /* ProductMajorVersion (1 byte) */

  Stream_Write_UINT8(s, versionInfo->ProductMinorVersion); /* ProductMinorVersion (1 byte) */

  Stream_Write_UINT16(s, versionInfo->ProductBuild);       /* ProductBuild (2 bytes) */

  Stream_Write(s, versionInfo->Reserved, sizeof(versionInfo->Reserved)); /* Reserved (3 bytes) */

  Stream_Write_UINT8(s, versionInfo->NTLMRevisionCurrent); /* NTLMRevisionCurrent (1 byte) */

  return TRUE;

}

/**

 * Print VERSION structure. msdn{cc236654}

 * @param versionInfo A pointer to the struct containing the data to print

 */

#ifdef WITH_DEBUG_NTLM

void ntlm_print_version_info(const NTLM_VERSION_INFO* versionInfo)

{

  WINPR_ASSERT(versionInfo);

  WLog_VRB(TAG, "VERSION ={");

  WLog_VRB(TAG, "\tProductMajorVersion: %" PRIu8 "", versionInfo->ProductMajorVersion);

  WLog_VRB(TAG, "\tProductMinorVersion: %" PRIu8 "", versionInfo->ProductMinorVersion);

  WLog_VRB(TAG, "\tProductBuild: %" PRIu16 "", versionInfo->ProductBuild);

  WLog_VRB(TAG, "\tReserved: 0x%02" PRIX8 "%02" PRIX8 "%02" PRIX8 "", versionInfo->Reserved[0],

           versionInfo->Reserved[1], versionInfo->Reserved[2]);

  WLog_VRB(TAG, "\tNTLMRevisionCurrent: 0x%02" PRIX8 "", versionInfo->NTLMRevisionCurrent);

}

#endif

static BOOL ntlm_read_ntlm_v2_client_challenge(wStream* s, NTLMv2_CLIENT_CHALLENGE* challenge)

{

  size_t size = 0;

  WINPR_ASSERT(s);

  WINPR_ASSERT(challenge);

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 28))

    return FALSE;

  Stream_Read_UINT8(s, challenge->RespType);

  Stream_Read_UINT8(s, challenge->HiRespType);

  Stream_Read_UINT16(s, challenge->Reserved1);

  Stream_Read_UINT32(s, challenge->Reserved2);

  Stream_Read(s, challenge->Timestamp, 8);

  Stream_Read(s, challenge->ClientChallenge, 8);

  Stream_Read_UINT32(s, challenge->Reserved3);

  size = Stream_Length(s) - Stream_GetPosition(s);

  if (size > UINT32_MAX)

  {

    WLog_ERR(TAG, "NTLMv2_CLIENT_CHALLENGE::cbAvPairs too large, got %" PRIuz "bytes", size);

    return FALSE;

  }

  challenge->cbAvPairs = (UINT32)size;

  challenge->AvPairs = (NTLM_AV_PAIR*)malloc(challenge->cbAvPairs);

  if (!challenge->AvPairs)

  {

    WLog_ERR(TAG, "NTLMv2_CLIENT_CHALLENGE::AvPairs failed to allocate %" PRIu32 "bytes",

             challenge->cbAvPairs);

    return FALSE;

  }

  Stream_Read(s, challenge->AvPairs, size);

  return TRUE;

}

static BOOL ntlm_write_ntlm_v2_client_challenge(wStream* s,

                                                const NTLMv2_CLIENT_CHALLENGE* challenge)

{

  ULONG length = 0;

  WINPR_ASSERT(s);

  WINPR_ASSERT(challenge);

  if (!NTLM_CheckAndLogRequiredCapacity(TAG, s, 28, "NTLMv2_CLIENT_CHALLENGE"))

    return FALSE;

  Stream_Write_UINT8(s, challenge->RespType);

  Stream_Write_UINT8(s, challenge->HiRespType);

  Stream_Write_UINT16(s, challenge->Reserved1);

  Stream_Write_UINT32(s, challenge->Reserved2);

  Stream_Write(s, challenge->Timestamp, 8);

  Stream_Write(s, challenge->ClientChallenge, 8);

  Stream_Write_UINT32(s, challenge->Reserved3);

  length = ntlm_av_pair_list_length(challenge->AvPairs, challenge->cbAvPairs);

  if (!Stream_CheckAndLogRequiredLength(TAG, s, length))

    return FALSE;

  Stream_Write(s, challenge->AvPairs, length);

  return TRUE;

}

BOOL ntlm_read_ntlm_v2_response(wStream* s, NTLMv2_RESPONSE* response)

{

  WINPR_ASSERT(s);

  WINPR_ASSERT(response);

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 16))

    return FALSE;

  Stream_Read(s, response->Response, 16);

  return ntlm_read_ntlm_v2_client_challenge(s, &(response->Challenge));

}

BOOL ntlm_write_ntlm_v2_response(wStream* s, const NTLMv2_RESPONSE* response)

{

  WINPR_ASSERT(s);

  WINPR_ASSERT(response);

  if (!NTLM_CheckAndLogRequiredCapacity(TAG, s, 16ull, "NTLMv2_RESPONSE"))

    return FALSE;

  Stream_Write(s, response->Response, 16);

  return ntlm_write_ntlm_v2_client_challenge(s, &(response->Challenge));

}

/**

 * Get current time, in tenths of microseconds since midnight of January 1, 1601.

 * @param[out] timestamp 64-bit little-endian timestamp

 */

static void ntlm_current_time(BYTE* timestamp, WINPR_ATTR_UNUSED size_t size)

{

  FILETIME ft = WINPR_C_ARRAY_INIT;

  WINPR_ASSERT(timestamp);

  WINPR_ASSERT(size >= sizeof(ft));

  GetSystemTimeAsFileTime(&ft);

  CopyMemory(timestamp, &(ft), sizeof(ft));

}

/**

 * Generate timestamp for AUTHENTICATE_MESSAGE.

 *

 * @param context A pointer to the NTLM context

 */

void ntlm_generate_timestamp(NTLM_CONTEXT* context)

{

  WINPR_ASSERT(context);

  if (memcmp(context->ChallengeTimestamp, NTLM_NULL_BUFFER, 8) != 0)

    CopyMemory(context->Timestamp, context->ChallengeTimestamp, 8);

  else

    ntlm_current_time(context->Timestamp, sizeof(context->Timestamp));

}

static BOOL ntlm_fetch_ntlm_v2_hash(NTLM_CONTEXT* context, BYTE* hash)

{

  BOOL rc = FALSE;

  WINPR_SAM* sam = nullptr;

  WINPR_SAM_ENTRY* entry = nullptr;

  SSPI_CREDENTIALS* credentials = nullptr;

  WINPR_ASSERT(context);

  WINPR_ASSERT(hash);

  credentials = context->credentials;

  sam = SamOpen(context->SamFile, TRUE);

  if (!sam)

    goto fail;

  entry = SamLookupUserW(

      sam, (LPWSTR)credentials->identity.User, credentials->identity.UserLength * sizeof(WCHAR),

      (LPWSTR)credentials->identity.Domain, credentials->identity.DomainLength * sizeof(WCHAR));

  if (!entry)

  {

    entry = SamLookupUserW(sam, (LPWSTR)credentials->identity.User,

                           credentials->identity.UserLength * sizeof(WCHAR), nullptr, 0);

  }

  if (!entry)

    goto fail;

#ifdef WITH_DEBUG_NTLM

  WLog_VRB(TAG, "NTLM Hash:");

  winpr_HexDump(TAG, WLOG_DEBUG, entry->NtHash, 16);

#endif

  rc = NTOWFv2FromHashW(entry->NtHash, (LPWSTR)credentials->identity.User,

                        credentials->identity.UserLength * sizeof(WCHAR),

                        (LPWSTR)credentials->identity.Domain,

                        credentials->identity.DomainLength * sizeof(WCHAR), hash);

fail:

  SamFreeEntry(sam, entry);

  SamClose(sam);

  if (!rc)

    WLog_ERR(TAG, "Error: Could not find user in SAM database");

  return rc;

}

static int hexchar2nibble(WCHAR wc)

{

#if defined(__BIG_ENDIAN__)

  union

  {

    BYTE b[2];

    WCHAR w;

  } cnv;

  cnv.w = wc;

  const BYTE b = cnv.b[0];

  cnv.b[0] = cnv.b[1];

  cnv.b[1] = b;

  wc = cnv.w;

#endif

  switch (wc)

  {

    case L'0':

    case L'1':

    case L'2':

    case L'3':

    case L'4':

    case L'5':

    case L'6':

    case L'7':

    case L'8':

    case L'9':

      return wc - L'0';

    case L'a':

    case L'b':

    case L'c':

    case L'd':

    case L'e':

    case L'f':

      return wc - L'a' + 10;

    case L'A':

    case L'B':

    case L'C':

    case L'D':

    case L'E':

    case L'F':

      return wc - L'A' + 10;

    default:

      return -1;

  }

}

static int ntlm_convert_password_hash(NTLM_CONTEXT* context, BYTE* hash, size_t hashlen)

{

  const size_t required_len = 2ull * hashlen;

  WINPR_ASSERT(context);

  WINPR_ASSERT(hash);

  SSPI_CREDENTIALS* credentials = context->credentials;

  /* Password contains a password hash of length (PasswordLength -

   * SSPI_CREDENTIALS_HASH_LENGTH_OFFSET) */

  const ULONG PasswordHashLength = credentials->identity.PasswordLength -

                                   /* Macro [globalScope] */ SSPI_CREDENTIALS_HASH_LENGTH_OFFSET;

  if (PasswordHashLength != required_len)

  {

    WLog_ERR(TAG,

             "PasswordHash has invalid length %" PRIu32 " must be exactly %" PRIuz " bytes",

             PasswordHashLength, required_len);

    return -1;

  }

  const WCHAR* PasswordHash = credentials->identity.Password;

  for (size_t x = 0; x < hashlen; x++)

  {

    const int hi = hexchar2nibble(PasswordHash[2 * x]);

    if (hi < 0)

    {

      WLog_ERR(TAG, "PasswordHash has an invalid value at position %" PRIuz, 2 * x);

      return -1;

    }

    const int lo = hexchar2nibble(PasswordHash[2 * x + 1]);

    if (lo < 0)

    {

      WLog_ERR(TAG, "PasswordHash has an invalid value at position %" PRIuz, 2 * x + 1);

      return -1;

    }

    const BYTE val = (BYTE)((hi << 4) | lo);

    hash[x] = val;

  }

  return 1;

}

static BOOL ntlm_compute_ntlm_v2_hash(NTLM_CONTEXT* context, BYTE* hash)

{

  SSPI_CREDENTIALS* credentials = nullptr;

  WINPR_ASSERT(context);

  WINPR_ASSERT(hash);

  credentials = context->credentials;

#ifdef WITH_DEBUG_NTLM

  if (credentials)

  {

    WLog_VRB(TAG, "Password (length = %" PRIu32 ")", credentials->identity.PasswordLength * 2);

    winpr_HexDump(TAG, WLOG_TRACE, (BYTE*)credentials->identity.Password,

                  credentials->identity.PasswordLength * 2);

    WLog_VRB(TAG, "Username (length = %" PRIu32 ")", credentials->identity.UserLength * 2);

    winpr_HexDump(TAG, WLOG_TRACE, (BYTE*)credentials->identity.User,

                  credentials->identity.UserLength * 2);

    WLog_VRB(TAG, "Domain (length = %" PRIu32 ")", credentials->identity.DomainLength * 2);

    winpr_HexDump(TAG, WLOG_TRACE, (BYTE*)credentials->identity.Domain,

                  credentials->identity.DomainLength * 2);

  }

  else

    WLog_VRB(TAG, "Strange, NTLM_CONTEXT is missing valid credentials...");

  WLog_VRB(TAG, "Workstation (length = %" PRIu16 ")", context->Workstation.Length);

  winpr_HexDump(TAG, WLOG_TRACE, (BYTE*)context->Workstation.Buffer, context->Workstation.Length);

  WLog_VRB(TAG, "NTOWFv2, NTLMv2 Hash");

  winpr_HexDump(TAG, WLOG_TRACE, context->NtlmV2Hash, WINPR_MD5_DIGEST_LENGTH);

#endif

  if (memcmp(context->NtlmV2Hash, NTLM_NULL_BUFFER, 16) != 0)

    return TRUE;

  if (!credentials)

    return FALSE;

  else if (memcmp(context->NtlmHash, NTLM_NULL_BUFFER, 16) != 0)

  {

    return NTOWFv2FromHashW(context->NtlmHash, (LPWSTR)credentials->identity.User,

                            credentials->identity.UserLength * 2,

                            (LPWSTR)credentials->identity.Domain,

                            credentials->identity.DomainLength * 2, hash);

  }

  else if (credentials->identity.PasswordLength > SSPI_CREDENTIALS_HASH_LENGTH_OFFSET)

  {

    /* Special case for WinPR: password hash */

    if (ntlm_convert_password_hash(context, context->NtlmHash, sizeof(context->NtlmHash)) < 0)

      return FALSE;

    return NTOWFv2FromHashW(context->NtlmHash, (LPWSTR)credentials->identity.User,

                            credentials->identity.UserLength * 2,

                            (LPWSTR)credentials->identity.Domain,

                            credentials->identity.DomainLength * 2, hash);

  }

  else if (credentials->identity.Password)

  {

    return NTOWFv2W(

        (LPWSTR)credentials->identity.Password, credentials->identity.PasswordLength * 2,

        (LPWSTR)credentials->identity.User, credentials->identity.UserLength * 2,

        (LPWSTR)credentials->identity.Domain, credentials->identity.DomainLength * 2, hash);

  }

  else if (context->HashCallback)

  {

    SecBuffer proofValue = WINPR_C_ARRAY_INIT;

    SecBuffer micValue = WINPR_C_ARRAY_INIT;

    if (ntlm_computeProofValue(context, &proofValue) != SEC_E_OK)

      return FALSE;

    if (ntlm_computeMicValue(context, &micValue) != SEC_E_OK)

    {

      sspi_SecBufferFree(&proofValue);

      return FALSE;

    }

    const SECURITY_STATUS ret = context->HashCallback(

        context->HashCallbackArg, &credentials->identity, &proofValue,

        context->EncryptedRandomSessionKey, context->AUTHENTICATE_MESSAGE.MessageIntegrityCheck,

        &micValue, hash);

    sspi_SecBufferFree(&proofValue);

    sspi_SecBufferFree(&micValue);

    return ret == SEC_E_OK;

  }

  else if (context->UseSamFileDatabase)

  {

    return ntlm_fetch_ntlm_v2_hash(context, hash);

  }

  return TRUE;

}

SECURITY_STATUS ntlm_compute_lm_v2_response(NTLM_CONTEXT* context)

{

  BYTE* response = nullptr;

  BYTE value[WINPR_MD5_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;

  WINPR_ASSERT(context);

  if (context->LmCompatibilityLevel < 2)

  {

    if (!sspi_SecBufferAlloc(&context->LmChallengeResponse, 24))

      return SEC_E_INSUFFICIENT_MEMORY;

    ZeroMemory(context->LmChallengeResponse.pvBuffer, 24);

    return SEC_E_OK;

  }

  /* Compute the NTLMv2 hash */

  if (!ntlm_compute_ntlm_v2_hash(context, context->NtlmV2Hash))

    return SEC_E_NO_CREDENTIALS;

  /* Concatenate the server and client challenges */

  CopyMemory(value, context->ServerChallenge, 8);

  CopyMemory(&value[8], context->ClientChallenge, 8);

  if (!sspi_SecBufferAlloc(&context->LmChallengeResponse, 24))

    return SEC_E_INSUFFICIENT_MEMORY;

  response = (BYTE*)context->LmChallengeResponse.pvBuffer;

  /* Compute the HMAC-MD5 hash of the resulting value using the NTLMv2 hash as the key */

  if (!winpr_HMAC(WINPR_MD_MD5, (void*)context->NtlmV2Hash, WINPR_MD5_DIGEST_LENGTH, (BYTE*)value,

                  WINPR_MD5_DIGEST_LENGTH, response, WINPR_MD5_DIGEST_LENGTH))

    return SEC_E_ALGORITHM_MISMATCH;

  /* Concatenate the resulting HMAC-MD5 hash and the client challenge, giving us the LMv2 response

   * (24 bytes) */

  CopyMemory(&response[16], context->ClientChallenge, 8);

  return SEC_E_OK;

}

/**

 * Compute NTLMv2 Response.

 *

 * NTLMv2_RESPONSE msdn{cc236653}

 * NTLMv2 Authentication msdn{cc236700}

 *

 * @param context A pointer to the NTLM context

 * @return \b TRUE for success, \b FALSE for failure

 */

SECURITY_STATUS ntlm_compute_ntlm_v2_response(NTLM_CONTEXT* context)

{

  SecBuffer ntlm_v2_temp = WINPR_C_ARRAY_INIT;

  SecBuffer ntlm_v2_temp_chal = WINPR_C_ARRAY_INIT;

  WINPR_ASSERT(context);

  PSecBuffer TargetInfo = &context->ChallengeTargetInfo;

  SECURITY_STATUS ret = SEC_E_INSUFFICIENT_MEMORY;

  if (!sspi_SecBufferAlloc(&ntlm_v2_temp, TargetInfo->cbBuffer + 28))

    goto exit;

  ZeroMemory(ntlm_v2_temp.pvBuffer, ntlm_v2_temp.cbBuffer);

  {

    BYTE* blob = (BYTE*)ntlm_v2_temp.pvBuffer;

    /* Compute the NTLMv2 hash */

    ret = SEC_E_NO_CREDENTIALS;

    if (!ntlm_compute_ntlm_v2_hash(context, (BYTE*)context->NtlmV2Hash))

      goto exit;

    /* Construct temp */

    blob[0] = 1; /* RespType (1 byte) */

    blob[1] = 1; /* HighRespType (1 byte) */

    /* Reserved1 (2 bytes) */

    /* Reserved2 (4 bytes) */

    CopyMemory(&blob[8], context->Timestamp, 8);        /* Timestamp (8 bytes) */

    CopyMemory(&blob[16], context->ClientChallenge, 8); /* ClientChallenge (8 bytes) */

    /* Reserved3 (4 bytes) */

    CopyMemory(&blob[28], TargetInfo->pvBuffer, TargetInfo->cbBuffer);

#ifdef WITH_DEBUG_NTLM

    WLog_VRB(TAG, "NTLMv2 Response Temp Blob");

    winpr_HexDump(TAG, WLOG_TRACE, ntlm_v2_temp.pvBuffer, ntlm_v2_temp.cbBuffer);

#endif

  }

  /* Concatenate server challenge with temp */

  ret = SEC_E_INSUFFICIENT_MEMORY;

  if (!sspi_SecBufferAlloc(&ntlm_v2_temp_chal, ntlm_v2_temp.cbBuffer + 8))

    goto exit;

  {

    BYTE* blob = (BYTE*)ntlm_v2_temp_chal.pvBuffer;

    CopyMemory(blob, context->ServerChallenge, 8);

    CopyMemory(&blob[8], ntlm_v2_temp.pvBuffer, ntlm_v2_temp.cbBuffer);

    if (!winpr_HMAC(WINPR_MD_MD5, (BYTE*)context->NtlmV2Hash, WINPR_MD5_DIGEST_LENGTH,

                    (BYTE*)ntlm_v2_temp_chal.pvBuffer, ntlm_v2_temp_chal.cbBuffer,

                    context->NtProofString, WINPR_MD5_DIGEST_LENGTH))

      goto exit;

  }

  /* NtChallengeResponse, Concatenate NTProofStr with temp */

  if (!sspi_SecBufferAlloc(&context->NtChallengeResponse, ntlm_v2_temp.cbBuffer + 16))

    goto exit;

  {

    BYTE* blob = (BYTE*)context->NtChallengeResponse.pvBuffer;

    CopyMemory(blob, context->NtProofString, WINPR_MD5_DIGEST_LENGTH);

    CopyMemory(&blob[16], ntlm_v2_temp.pvBuffer, ntlm_v2_temp.cbBuffer);

  }

  /* Compute SessionBaseKey, the HMAC-MD5 hash of NTProofStr using the NTLMv2 hash as the key */

  if (!winpr_HMAC(WINPR_MD_MD5, (BYTE*)context->NtlmV2Hash, WINPR_MD5_DIGEST_LENGTH,

                  context->NtProofString, WINPR_MD5_DIGEST_LENGTH, context->SessionBaseKey,

                  WINPR_MD5_DIGEST_LENGTH))

    goto exit;

  ret = SEC_E_OK;

exit:

  sspi_SecBufferFree(&ntlm_v2_temp);

  sspi_SecBufferFree(&ntlm_v2_temp_chal);

  return ret;

}

/**

 * Encrypt the given plain text using RC4 and the given key.

 * @param key RC4 key

 * @param length text length

 * @param plaintext plain text

 * @param ciphertext cipher text

 */

BOOL ntlm_rc4k(BYTE* key, size_t length, BYTE* plaintext, BYTE* ciphertext)

{

  WINPR_RC4_CTX* rc4 = winpr_RC4_New(key, 16);

  if (!rc4)

    return FALSE;

  const BOOL rc = winpr_RC4_Update(rc4, length, plaintext, ciphertext);

  winpr_RC4_Free(rc4);

  return rc;

}

/**

 * Generate client challenge (8-byte nonce).

 * @param context A pointer to the NTLM context

 */

BOOL ntlm_generate_client_challenge(NTLM_CONTEXT* context)

{

  WINPR_ASSERT(context);

  /* ClientChallenge is used in computation of LMv2 and NTLMv2 responses */

  if (memcmp(context->ClientChallenge, NTLM_NULL_BUFFER, sizeof(context->ClientChallenge)) != 0)

    return TRUE;

  return winpr_RAND(context->ClientChallenge, sizeof(context->ClientChallenge)) >= 0;

}

/**

 * Generate server challenge (8-byte nonce).

 * @param context A pointer to the NTLM context

 */

BOOL ntlm_generate_server_challenge(NTLM_CONTEXT* context)

{

  WINPR_ASSERT(context);

  if (memcmp(context->ServerChallenge, NTLM_NULL_BUFFER, sizeof(context->ServerChallenge)) != 0)

    return TRUE;

  return winpr_RAND(context->ServerChallenge, sizeof(context->ServerChallenge)) >= 0;

}

/**

 * Generate KeyExchangeKey (the 128-bit SessionBaseKey). msdn{cc236710}

 * @param context A pointer to the NTLM context

 */

BOOL ntlm_generate_key_exchange_key(NTLM_CONTEXT* context)

{

  WINPR_ASSERT(context);

  WINPR_ASSERT(sizeof(context->KeyExchangeKey) == sizeof(context->SessionBaseKey));

  /* In NTLMv2, KeyExchangeKey is the 128-bit SessionBaseKey */

  CopyMemory(context->KeyExchangeKey, context->SessionBaseKey, sizeof(context->KeyExchangeKey));

  return TRUE;

}

/**

 * Generate RandomSessionKey (16-byte nonce).

 * @param context A pointer to the NTLM context

 */

BOOL ntlm_generate_random_session_key(NTLM_CONTEXT* context)

{

  WINPR_ASSERT(context);

  return winpr_RAND(context->RandomSessionKey, sizeof(context->RandomSessionKey)) >= 0;

}

/**

 * Generate ExportedSessionKey (the RandomSessionKey, exported)

 * @param context A pointer to the NTLM context

 */

BOOL ntlm_generate_exported_session_key(NTLM_CONTEXT* context)

{

  WINPR_ASSERT(context);

  WINPR_ASSERT(sizeof(context->ExportedSessionKey) >= sizeof(context->RandomSessionKey));

  CopyMemory(context->ExportedSessionKey, context->RandomSessionKey,

             sizeof(context->ExportedSessionKey));

  return TRUE;

}

/**

 * Encrypt RandomSessionKey (RC4-encrypted RandomSessionKey, using KeyExchangeKey as the key).

 * @param context A pointer to the NTLM context

 */

BOOL ntlm_encrypt_random_session_key(NTLM_CONTEXT* context)

{

  /* In NTLMv2, EncryptedRandomSessionKey is the ExportedSessionKey RC4-encrypted with the

   * KeyExchangeKey */

  WINPR_ASSERT(context);

  return ntlm_rc4k(context->KeyExchangeKey, 16, context->RandomSessionKey,

                   context->EncryptedRandomSessionKey);

}

/**

 * Decrypt RandomSessionKey (RC4-encrypted RandomSessionKey, using KeyExchangeKey as the key).

 * @param context A pointer to the NTLM context

 */

BOOL ntlm_decrypt_random_session_key(NTLM_CONTEXT* context)

{

  WINPR_ASSERT(context);

  /* In NTLMv2, EncryptedRandomSessionKey is the ExportedSessionKey RC4-encrypted with the

   * KeyExchangeKey */

  /**

   *  if (NegotiateFlags & NTLMSSP_NEGOTIATE_KEY_EXCH)

   *    Set RandomSessionKey to RC4K(KeyExchangeKey,

   * AUTHENTICATE_MESSAGE.EncryptedRandomSessionKey) else Set RandomSessionKey to KeyExchangeKey

   */

  if (context->NegotiateKeyExchange)

  {

    WINPR_ASSERT(sizeof(context->EncryptedRandomSessionKey) ==

                 sizeof(context->RandomSessionKey));

    return ntlm_rc4k(context->KeyExchangeKey, sizeof(context->EncryptedRandomSessionKey),

                     context->EncryptedRandomSessionKey, context->RandomSessionKey);

  }

  else

  {

    WINPR_ASSERT(sizeof(context->RandomSessionKey) == sizeof(context->KeyExchangeKey));

    CopyMemory(context->RandomSessionKey, context->KeyExchangeKey,

               sizeof(context->RandomSessionKey));

  }

  return TRUE;

}

/**

 * Generate signing key msdn{cc236711}

 *

 * @param exported_session_key ExportedSessionKey

 * @param sign_magic Sign magic string

 * @param signing_key Destination signing key

 *

 * @return \b TRUE for success, \b FALSE for failure

 */

static BOOL ntlm_generate_signing_key(BYTE* exported_session_key, const SecBuffer* sign_magic,

                                      BYTE* signing_key)

{

  BOOL rc = FALSE;

  size_t length = 0;

  BYTE* value = nullptr;

  WINPR_ASSERT(exported_session_key);

  WINPR_ASSERT(sign_magic);

  WINPR_ASSERT(signing_key);

  length = WINPR_MD5_DIGEST_LENGTH + sign_magic->cbBuffer;

  value = (BYTE*)malloc(length);

  if (!value)

    goto out;

  /* Concatenate ExportedSessionKey with sign magic */

  CopyMemory(value, exported_session_key, WINPR_MD5_DIGEST_LENGTH);

  CopyMemory(&value[WINPR_MD5_DIGEST_LENGTH], sign_magic->pvBuffer, sign_magic->cbBuffer);

  rc = winpr_Digest(WINPR_MD_MD5, value, length, signing_key, WINPR_MD5_DIGEST_LENGTH);

out:

  free(value);

  return rc;

}

/**

 * Generate client signing key (ClientSigningKey). msdn{cc236711}

 * @param context A pointer to the NTLM context

 *

 * @return \b TRUE for success, \b FALSE for failure

 */

BOOL ntlm_generate_client_signing_key(NTLM_CONTEXT* context)

{

  const SecBuffer signMagic = { sizeof(NTLM_CLIENT_SIGN_MAGIC), 0, NTLM_CLIENT_SIGN_MAGIC };

  WINPR_ASSERT(context);

  return ntlm_generate_signing_key(context->ExportedSessionKey, &signMagic,

                                   context->ClientSigningKey);

}

/**

 * Generate server signing key (ServerSigningKey). msdn{cc236711}

 * @param context A pointer to the NTLM context

 *

 * @return \b TRUE for success, \b FALSE for failure

 */

BOOL ntlm_generate_server_signing_key(NTLM_CONTEXT* context)

{

  const SecBuffer signMagic = { sizeof(NTLM_SERVER_SIGN_MAGIC), 0, NTLM_SERVER_SIGN_MAGIC };

  WINPR_ASSERT(context);

  return ntlm_generate_signing_key(context->ExportedSessionKey, &signMagic,

                                   context->ServerSigningKey);

}

/**

 * Generate client sealing key (ClientSealingKey). msdn{cc236712}

 * @param context A pointer to the NTLM context

 *

 * @return \b TRUE for success, \b FALSE for failure

 */

BOOL ntlm_generate_client_sealing_key(NTLM_CONTEXT* context)

{

  const SecBuffer sealMagic = { sizeof(NTLM_CLIENT_SEAL_MAGIC), 0, NTLM_CLIENT_SEAL_MAGIC };

  WINPR_ASSERT(context);

  return ntlm_generate_signing_key(context->ExportedSessionKey, &sealMagic,

                                   context->ClientSealingKey);

}

/**

 * Generate server sealing key (ServerSealingKey). msdn{cc236712}

 * @param context A pointer to the NTLM context

 *

 * @return \b TRUE for success, \b FALSE for failure

 */

BOOL ntlm_generate_server_sealing_key(NTLM_CONTEXT* context)

{

  const SecBuffer sealMagic = { sizeof(NTLM_SERVER_SEAL_MAGIC), 0, NTLM_SERVER_SEAL_MAGIC };

  WINPR_ASSERT(context);

  return ntlm_generate_signing_key(context->ExportedSessionKey, &sealMagic,

                                   context->ServerSealingKey);

}

/**

 * Initialize RC4 stream cipher states for sealing.

 * @param context A pointer to the NTLM context

 */

BOOL ntlm_init_rc4_seal_states(NTLM_CONTEXT* context)

{

  WINPR_ASSERT(context);

  if (context->server)

  {

    context->SendSigningKey = context->ServerSigningKey;

    context->RecvSigningKey = context->ClientSigningKey;

    context->SendSealingKey = context->ClientSealingKey;

    context->RecvSealingKey = context->ServerSealingKey;

    context->SendRc4Seal =

        winpr_RC4_New(context->ServerSealingKey, sizeof(context->ServerSealingKey));

    context->RecvRc4Seal =

        winpr_RC4_New(context->ClientSealingKey, sizeof(context->ClientSealingKey));

  }

  else

  {

    context->SendSigningKey = context->ClientSigningKey;

    context->RecvSigningKey = context->ServerSigningKey;

    context->SendSealingKey = context->ServerSealingKey;

    context->RecvSealingKey = context->ClientSealingKey;

    context->SendRc4Seal =

        winpr_RC4_New(context->ClientSealingKey, sizeof(context->ClientSealingKey));

    context->RecvRc4Seal =

        winpr_RC4_New(context->ServerSealingKey, sizeof(context->ServerSealingKey));

  }

  if (!context->SendRc4Seal)

  {

    WLog_ERR(TAG, "Failed to allocate context->SendRc4Seal");

    return FALSE;

  }

  if (!context->RecvRc4Seal)

  {

    WLog_ERR(TAG, "Failed to allocate context->RecvRc4Seal");

    return FALSE;

  }

  return TRUE;

}

BOOL ntlm_compute_message_integrity_check(NTLM_CONTEXT* context, BYTE* mic, UINT32 size)

{

  BOOL rc = FALSE;

  /*

   * Compute the HMAC-MD5 hash of ConcatenationOf(NEGOTIATE_MESSAGE,

   * CHALLENGE_MESSAGE, AUTHENTICATE_MESSAGE) using the ExportedSessionKey

   */

  WINPR_HMAC_CTX* hmac = winpr_HMAC_New();