/**

 * FreeRDP: A Remote Desktop Protocol Implementation

 * ASN.1 Basic Encoding Rules (BER)

 *

 * Copyright 2011-2012 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 <freerdp/config.h>

#include <stdio.h>

#include <winpr/assert.h>

#include <winpr/cast.h>

#include <winpr/crt.h>

#include <winpr/string.h>

#include <freerdp/log.h>

#include <freerdp/crypto/ber.h>

#define TAG FREERDP_TAG("crypto")

BOOL ber_read_length(wStream* s, size_t* length)

{

  BYTE byte = 0;

  WINPR_ASSERT(s);

  WINPR_ASSERT(length);

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))

    return FALSE;

  Stream_Read_UINT8(s, byte);

  if (byte & 0x80)

  {

    byte &= ~(0x80);

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

      return FALSE;

    if (byte == 1)

      Stream_Read_UINT8(s, *length);

    else if (byte == 2)

      Stream_Read_UINT16_BE(s, *length);

    else

    {

      WLog_ERR(TAG, "ber: unexpected byte 0x%02" PRIx8 ", expected [1,2]", byte);

      return FALSE;

    }

  }

  else

  {

    *length = byte;

  }

  return TRUE;

}

/**

 * Write BER length.

 * @param s stream

 * @param length length

 */

size_t ber_write_length(wStream* s, size_t length)

{

  WINPR_ASSERT(s);

  if (length > 0xFF)

  {

    WINPR_ASSERT(length <= UINT16_MAX);

    WINPR_ASSERT(Stream_GetRemainingCapacity(s) >= 3);

    Stream_Write_UINT8(s, 0x80 ^ 2);

    Stream_Write_UINT16_BE(s, (UINT16)length);

    return 3;

  }

  WINPR_ASSERT(length <= UINT8_MAX);

  if (length > 0x7F)

  {

    WINPR_ASSERT(Stream_GetRemainingCapacity(s) >= 2);

    Stream_Write_UINT8(s, 0x80 ^ 1);

    Stream_Write_UINT8(s, (UINT8)length);

    return 2;

  }

  WINPR_ASSERT(Stream_GetRemainingCapacity(s) >= 1);

  Stream_Write_UINT8(s, (UINT8)length);

  return 1;

}

size_t _ber_sizeof_length(size_t length)

{

  if (length > 0xFF)

    return 3;

  if (length > 0x7F)

    return 2;

  return 1;

}

/**

 * Read BER Universal tag.

 *

 * @param s The stream to read from

 * @param tag BER universally-defined tag

 *

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

 */

BOOL ber_read_universal_tag(wStream* s, BYTE tag, BOOL pc)

{

  BYTE byte = 0;

  const BYTE expect = (BER_CLASS_UNIV | BER_PC(pc) | (BER_TAG_MASK & tag));

  WINPR_ASSERT(s);

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))

    return FALSE;

  Stream_Read_UINT8(s, byte);

  if (byte != expect)

  {

    WLog_WARN(TAG, "invalid tag, got 0x%02" PRIx8 ", expected 0x%02" PRIx8, byte, expect);

    return FALSE;

  }

  return TRUE;

}

/**

 * Write BER Universal tag.

 * @param s stream

 * @param tag BER universally-defined tag

 * @param pc primitive (FALSE) or constructed (TRUE)

 */

size_t ber_write_universal_tag(wStream* s, BYTE tag, BOOL pc)

{

  WINPR_ASSERT(s);

  Stream_Write_UINT8(s, (BER_CLASS_UNIV | BER_PC(pc)) | (BER_TAG_MASK & tag));

  return 1;

}

/**

 * Read BER Application tag.

 * @param s stream

 * @param tag BER application-defined tag

 * @param length length

 */

BOOL ber_read_application_tag(wStream* s, BYTE tag, size_t* length)

{

  BYTE byte = 0;

  WINPR_ASSERT(s);

  WINPR_ASSERT(length);

  if (tag > 30)

  {

    const BYTE expect = ((BER_CLASS_APPL | BER_CONSTRUCT) | BER_TAG_MASK);

    if (!Stream_CheckAndLogRequiredLength(TAG, s, 2))

      return FALSE;

    Stream_Read_UINT8(s, byte);

    if (byte != expect)

    {

      WLog_WARN(TAG, "invalid tag, got 0x%02" PRIx8 ", expected 0x%02" PRIx8, byte, expect);

      return FALSE;

    }

    Stream_Read_UINT8(s, byte);

    if (byte != tag)

    {

      WLog_WARN(TAG, "invalid tag, got 0x%02" PRIx8 ", expected 0x%02" PRIx8, byte, tag);

      return FALSE;

    }

    return ber_read_length(s, length);

  }

  else

  {

    const BYTE expect = ((BER_CLASS_APPL | BER_CONSTRUCT) | (BER_TAG_MASK & tag));

    if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))

      return FALSE;

    Stream_Read_UINT8(s, byte);

    if (byte != expect)

    {

      WLog_WARN(TAG, "invalid tag, got 0x%02" PRIx8 ", expected 0x%02" PRIx8, byte, expect);

      return FALSE;

    }

    return ber_read_length(s, length);

  }

  return TRUE;

}

/**

 * Write BER Application tag.

 * @param s stream

 * @param tag BER application-defined tag

 * @param length length

 */

void ber_write_application_tag(wStream* s, BYTE tag, size_t length)

{

  WINPR_ASSERT(s);

  if (tag > 30)

  {

    WINPR_ASSERT(Stream_GetRemainingCapacity(s) >= 2);

    Stream_Write_UINT8(s, (BER_CLASS_APPL | BER_CONSTRUCT) | BER_TAG_MASK);

    Stream_Write_UINT8(s, tag);

    ber_write_length(s, length);

  }

  else

  {

    WINPR_ASSERT(Stream_GetRemainingCapacity(s) >= 1);

    Stream_Write_UINT8(s, (BER_CLASS_APPL | BER_CONSTRUCT) | (BER_TAG_MASK & tag));

    ber_write_length(s, length);

  }

}

BOOL ber_read_contextual_tag(wStream* s, BYTE tag, size_t* length, BOOL pc)

{

  const BYTE expect = ((BER_CLASS_CTXT | BER_PC(pc)) | (BER_TAG_MASK & tag));

  BYTE byte = 0;

  WINPR_ASSERT(s);

  WINPR_ASSERT(length);

  if (Stream_GetRemainingLength(s) < 1)

  {

    WLog_VRB(TAG, "short data, got %" PRIuz ", expected %u", Stream_GetRemainingLength(s), 1u);

    return FALSE;

  }

  Stream_Read_UINT8(s, byte);

  if (byte != expect)

  {

    WLog_VRB(TAG, "invalid tag, got 0x%02" PRIx8 ", expected 0x%02" PRIx8, byte, expect);

    Stream_Rewind(s, 1);

    return FALSE;

  }

  return ber_read_length(s, length);

}

size_t ber_write_contextual_tag(wStream* s, BYTE tag, size_t length, BOOL pc)

{

  WINPR_ASSERT(s);

  WINPR_ASSERT(Stream_GetRemainingCapacity(s) >= 1);

  Stream_Write_UINT8(s, (BER_CLASS_CTXT | BER_PC(pc)) | (BER_TAG_MASK & tag));

  return 1 + ber_write_length(s, length);

}

size_t ber_sizeof_contextual_tag(size_t length)

{

  return 1 + _ber_sizeof_length(length);

}

BOOL ber_read_sequence_tag(wStream* s, size_t* length)

{

  const BYTE expect = ((BER_CLASS_UNIV | BER_CONSTRUCT) | (BER_TAG_SEQUENCE_OF));

  BYTE byte = 0;

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))

    return FALSE;

  Stream_Read_UINT8(s, byte);

  if (byte != expect)

  {

    WLog_WARN(TAG, "invalid tag, got 0x%02" PRIx8 ", expected 0x%02" PRIx8, byte, expect);

    return FALSE;

  }

  return ber_read_length(s, length);

}

/**

 * Write BER SEQUENCE tag.

 * @param s stream

 * @param length length

 */

size_t ber_write_sequence_tag(wStream* s, size_t length)

{

  Stream_Write_UINT8(s, (BER_CLASS_UNIV | BER_CONSTRUCT) | (BER_TAG_MASK & BER_TAG_SEQUENCE));

  return 1 + ber_write_length(s, length);

}

size_t ber_sizeof_sequence(size_t length)

{

  return 1 + _ber_sizeof_length(length) + length;

}

size_t ber_sizeof_sequence_tag(size_t length)

{

  return 1 + _ber_sizeof_length(length);

}

BOOL ber_read_enumerated(wStream* s, BYTE* enumerated, BYTE count)

{

  size_t length = 0;

  WINPR_ASSERT(enumerated);

  if (!ber_read_universal_tag(s, BER_TAG_ENUMERATED, FALSE) || !ber_read_length(s, &length))

    return FALSE;

  if (length != 1)

  {

    WLog_WARN(TAG, "short data, got %" PRIuz ", expected %u", length, 1u);

    return FALSE;

  }

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))

    return FALSE;

  Stream_Read_UINT8(s, *enumerated);

  /* check that enumerated value falls within expected range */

  if (*enumerated + 1 > count)

  {

    WLog_WARN(TAG, "invalid data, expected %" PRIu8 " < %" PRIu8, *enumerated, count);

    return FALSE;

  }

  return TRUE;

}

void ber_write_enumerated(wStream* s, BYTE enumerated, WINPR_ATTR_UNUSED BYTE count)

{

  ber_write_universal_tag(s, BER_TAG_ENUMERATED, FALSE);

  ber_write_length(s, 1);

  Stream_Write_UINT8(s, enumerated);

}

BOOL ber_read_bit_string(wStream* s, size_t* length, BYTE* padding)

{

  if (!ber_read_universal_tag(s, BER_TAG_BIT_STRING, FALSE) || !ber_read_length(s, length))

    return FALSE;

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))

    return FALSE;

  Stream_Read_UINT8(s, *padding);

  return TRUE;

}

/**

 * Write a BER OCTET_STRING

 * @param s stream

 * @param oct_str octet string

 * @param length string length

 */

size_t ber_write_octet_string(wStream* s, const BYTE* oct_str, size_t length)

{

  size_t size = 0;

  WINPR_ASSERT(oct_str || (length == 0));

  size += ber_write_universal_tag(s, BER_TAG_OCTET_STRING, FALSE);

  size += ber_write_length(s, length);

  Stream_Write(s, oct_str, length);

  size += length;

  return size;

}

size_t ber_write_contextual_octet_string(wStream* s, BYTE tag, const BYTE* oct_str, size_t length)

{

  size_t inner = ber_sizeof_octet_string(length);

  size_t ret = 0;

  size_t r = 0;

  ret = ber_write_contextual_tag(s, tag, inner, TRUE);

  if (!ret)

    return 0;

  r = ber_write_octet_string(s, oct_str, length);

  if (!r)

    return 0;

  return ret + r;

}

size_t ber_write_char_to_unicode_octet_string(wStream* s, const char* str)

{

  WINPR_ASSERT(str);

  size_t size = 0;

  size_t length = strlen(str) + 1;

  size += ber_write_universal_tag(s, BER_TAG_OCTET_STRING, FALSE);

  size += ber_write_length(s, length * sizeof(WCHAR));

  if (Stream_Write_UTF16_String_From_UTF8(s, length, str, length, TRUE) < 0)

    return 0;

  return size + length * sizeof(WCHAR);

}

size_t ber_write_contextual_unicode_octet_string(wStream* s, BYTE tag, LPWSTR str)

{

  WINPR_ASSERT(str);

  size_t len = _wcslen(str) * sizeof(WCHAR);

  size_t inner_len = ber_sizeof_octet_string(len);

  size_t ret = 0;

  ret = ber_write_contextual_tag(s, tag, inner_len, TRUE);

  return ret + ber_write_octet_string(s, (const BYTE*)str, len);

}

size_t ber_write_contextual_char_to_unicode_octet_string(wStream* s, BYTE tag, const char* str)

{

  size_t ret = 0;

  size_t len = strlen(str);

  size_t inner_len = ber_sizeof_octet_string(len * 2);

  WINPR_ASSERT(Stream_GetRemainingCapacity(s) < ber_sizeof_contextual_tag(inner_len) + inner_len);

  ret = ber_write_contextual_tag(s, tag, inner_len, TRUE);

  ret += ber_write_universal_tag(s, BER_TAG_OCTET_STRING, FALSE);

  ret += ber_write_length(s, len * sizeof(WCHAR));

  if (Stream_Write_UTF16_String_From_UTF8(s, len, str, len, TRUE) < 0)

    return 0;

  return ret + len;

}

BOOL ber_read_unicode_octet_string(wStream* s, LPWSTR* str)

{

  LPWSTR ret = NULL;

  size_t length = 0;

  if (!ber_read_octet_string_tag(s, &length))

    return FALSE;

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

    return FALSE;

  ret = calloc(1, length + 2);

  if (!ret)

    return FALSE;

  memcpy(ret, Stream_ConstPointer(s), length);

  ret[length / 2] = 0;

  Stream_Seek(s, length);

  *str = ret;

  return TRUE;

}

BOOL ber_read_char_from_unicode_octet_string(wStream* s, char** str)

{

  size_t length = 0;

  char* ptr = NULL;

  *str = NULL;

  if (!ber_read_octet_string_tag(s, &length))

    return FALSE;

  ptr = Stream_Read_UTF16_String_As_UTF8(s, length / sizeof(WCHAR), NULL);

  if (!ptr)

    return FALSE;

  *str = ptr;

  return TRUE;

}

BOOL ber_read_octet_string_tag(wStream* s, size_t* length)

{

  return ber_read_universal_tag(s, BER_TAG_OCTET_STRING, FALSE) && ber_read_length(s, length);

}

BOOL ber_read_octet_string(wStream* s, BYTE** content, size_t* length)

{

  BYTE* ret = NULL;

  WINPR_ASSERT(s);

  WINPR_ASSERT(content);

  WINPR_ASSERT(length);

  if (!ber_read_octet_string_tag(s, length))

    return FALSE;

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

    return FALSE;

  ret = malloc(*length);

  if (!ret)

    return FALSE;

  Stream_Read(s, ret, *length);

  *content = ret;

  return TRUE;

}

size_t ber_write_octet_string_tag(wStream* s, size_t length)

{

  if (ber_write_universal_tag(s, BER_TAG_OCTET_STRING, FALSE) == 0)

    return 0;

  if (ber_write_length(s, length) == 0)

    return 0;

  return 1 + _ber_sizeof_length(length);

}

size_t ber_sizeof_octet_string(size_t length)

{

  return 1 + _ber_sizeof_length(length) + length;

}

size_t ber_sizeof_contextual_octet_string(size_t length)

{

  size_t ret = ber_sizeof_octet_string(length);

  return ber_sizeof_contextual_tag(ret) + ret;

}

/** \brief Read a BER BOOLEAN

 *

 * @param s The stream to read from.

 * @param value A pointer to the value read, must not be NULL

 *

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

 */

BOOL ber_read_BOOL(wStream* s, BOOL* value)

{

  size_t length = 0;

  BYTE v = 0;

  WINPR_ASSERT(value);

  if (!ber_read_universal_tag(s, BER_TAG_BOOLEAN, FALSE) || !ber_read_length(s, &length))

    return FALSE;

  if (length != 1)

  {

    WLog_WARN(TAG, "short data, got %" PRIuz ", expected %u", length, 1u);

    return FALSE;

  }

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 1))

    return FALSE;

  Stream_Read_UINT8(s, v);

  *value = (v ? TRUE : FALSE);

  return TRUE;

}

/**

 * Write a BER BOOLEAN

 *

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

 * @param value The value to write

 */

void ber_write_BOOL(wStream* s, BOOL value)

{

  ber_write_universal_tag(s, BER_TAG_BOOLEAN, FALSE);

  ber_write_length(s, 1);

  Stream_Write_UINT8(s, (value == TRUE) ? 0xFF : 0);

}

BOOL ber_read_integer(wStream* s, UINT32* value)

{

  size_t length = 0;

  WINPR_ASSERT(s);

  if (!ber_read_universal_tag(s, BER_TAG_INTEGER, FALSE))

    return FALSE;

  if (!ber_read_length(s, &length))

    return FALSE;

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

    return FALSE;

  if (value == NULL)

  {

    // even if we don't care the integer value, check the announced size

    return Stream_SafeSeek(s, length);

  }

  if (length == 1)

  {

    Stream_Read_UINT8(s, *value);

  }

  else if (length == 2)

  {

    Stream_Read_UINT16_BE(s, *value);

  }

  else if (length == 3)

  {

    BYTE byte = 0;

    Stream_Read_UINT8(s, byte);

    Stream_Read_UINT16_BE(s, *value);

    *value += (byte << 16) & 0xFF0000;

  }

  else if (length == 4)

  {

    Stream_Read_UINT32_BE(s, *value);

  }

  else if (length == 8)

  {

    WLog_ERR(TAG, "should implement reading an 8 bytes integer");

    return FALSE;

  }

  else

  {

    WLog_ERR(TAG, "should implement reading an integer with length=%" PRIuz, length);

    return FALSE;

  }

  return TRUE;

}

/**

 * Write a BER INTEGER

 *

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

 * @param value The value to write

 *

 * @return The size in bytes that were written

 */

size_t ber_write_integer(wStream* s, UINT32 value)

{

  WINPR_ASSERT(s);

  if (value < 0x80)

  {

    if (ber_write_universal_tag(s, BER_TAG_INTEGER, FALSE) == 0)

      return 0;

    if (ber_write_length(s, 1) == 0)

      return 0;

    Stream_Write_UINT8(s, WINPR_ASSERTING_INT_CAST(UINT8, value));

    return 3;

  }

  else if (value < 0x8000)

  {

    if (ber_write_universal_tag(s, BER_TAG_INTEGER, FALSE) == 0)

      return 0;

    if (ber_write_length(s, 2) == 0)

      return 0;

    Stream_Write_UINT16_BE(s, WINPR_ASSERTING_INT_CAST(UINT16, value));

    return 4;

  }

  else if (value < 0x800000)

  {

    if (ber_write_universal_tag(s, BER_TAG_INTEGER, FALSE) == 0)

      return 0;

    if (ber_write_length(s, 3) == 0)

      return 0;

    Stream_Write_UINT8(s, WINPR_ASSERTING_INT_CAST(UINT8, value >> 16));

    Stream_Write_UINT16_BE(s, WINPR_ASSERTING_INT_CAST(UINT16, value));

    return 5;

  }

  else if (value < 0x80000000)

  {

    if (ber_write_universal_tag(s, BER_TAG_INTEGER, FALSE) == 0)

      return 0;

    if (ber_write_length(s, 4) == 0)

      return 0;

    Stream_Write_UINT32_BE(s, value);

    return 6;

  }

  else

  {

    /* treat as signed integer i.e. NT/HRESULT error codes */

    if (ber_write_universal_tag(s, BER_TAG_INTEGER, FALSE) == 0)

      return 0;

    if (ber_write_length(s, 4) == 0)

      return 0;

    Stream_Write_UINT32_BE(s, value);

    return 6;

  }

}

size_t ber_write_contextual_integer(wStream* s, BYTE tag, UINT32 value)

{

  size_t len = ber_sizeof_integer(value);

  WINPR_ASSERT(s);

  WINPR_ASSERT(Stream_EnsureRemainingCapacity(s, len + 5));

  len += ber_write_contextual_tag(s, tag, len, TRUE);

  if (ber_write_integer(s, value) == 0)

    return 0;

  return len;

}

size_t ber_sizeof_integer(UINT32 value)

{

  if (value < 0x80)

  {

    return 3;

  }

  else if (value < 0x8000)

  {

    return 4;

  }

  else if (value < 0x800000)

  {

    return 5;

  }

  else if (value < 0x80000000)

  {

    return 6;

  }

  else

  {

    /* treat as signed integer i.e. NT/HRESULT error codes */

    return 6;

  }

}

size_t ber_sizeof_contextual_integer(UINT32 value)

{

  size_t intSize = ber_sizeof_integer(value);

  return ber_sizeof_contextual_tag(intSize) + intSize;

}

BOOL ber_read_integer_length(wStream* s, size_t* length)

{

  return ber_read_universal_tag(s, BER_TAG_INTEGER, FALSE) && ber_read_length(s, length);

}