/**

 * FreeRDP: A Remote Desktop Protocol Implementation

 * ASN.1 Packed 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 <winpr/assert.h>

#include <winpr/print.h>

#include <freerdp/config.h>

#include <freerdp/crypto/per.h>

#include <freerdp/log.h>

#define TAG FREERDP_TAG("crypto.per")

/**

 * Read PER length.

 *

 * @param s stream to read from

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

 *

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

 */

BOOL per_read_length(wStream* s, UINT16* length)

{

  BYTE byte = 0;

  WINPR_ASSERT(length);

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

    return FALSE;

  Stream_Read_UINT8(s, byte);

  if (byte & 0x80)

  {

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

      return FALSE;

    byte &= ~(0x80);

    *length = (byte << 8);

    Stream_Read_UINT8(s, byte);

    *length += byte;

  }

  else

  {

    *length = byte;

  }

  return TRUE;

}

/**

 * Write PER length.

 * @param s stream

 * @param length length

 *

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

 */

BOOL per_write_length(wStream* s, UINT16 length)

{

  if (length > 0x7F)

  {

    if (!Stream_EnsureRemainingCapacity(s, 2))

      return FALSE;

    Stream_Write_UINT16_BE(s, (length | 0x8000));

  }

  else

  {

    if (!Stream_EnsureRemainingCapacity(s, 1))

      return FALSE;

    Stream_Write_UINT8(s, (UINT8)length);

  }

  return TRUE;

}

/**

 * Read PER choice.

 * @param s stream

 * @param choice choice

 *

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

 */

BOOL per_read_choice(wStream* s, BYTE* choice)

{

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

    return FALSE;

  Stream_Read_UINT8(s, *choice);

  return TRUE;

}

/**

 * Write PER CHOICE.

 * @param s stream

 * @param choice index of chosen field

 *

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

 */

BOOL per_write_choice(wStream* s, BYTE choice)

{

  if (!Stream_EnsureRemainingCapacity(s, 1))

    return FALSE;

  Stream_Write_UINT8(s, choice);

  return TRUE;

}

/**

 * Read PER selection.

 * @param s stream

 * @param selection selection

 *

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

 */

BOOL per_read_selection(wStream* s, BYTE* selection)

{

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

    return FALSE;

  WINPR_ASSERT(selection);

  Stream_Read_UINT8(s, *selection);

  return TRUE;

}

/**

 * Write PER selection for OPTIONAL fields.

 * @param s stream

 * @param selection bit map of selected fields

 *

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

 */

BOOL per_write_selection(wStream* s, BYTE selection)

{

  if (!Stream_EnsureRemainingCapacity(s, 1))

    return FALSE;

  Stream_Write_UINT8(s, selection);

  return TRUE;

}

/**

 * Read PER number of sets.

 * @param s stream

 * @param number number of sets

 *

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

 */

BOOL per_read_number_of_sets(wStream* s, BYTE* number)

{

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

    return FALSE;

  WINPR_ASSERT(number);

  Stream_Read_UINT8(s, *number);

  return TRUE;

}

/**

 * Write PER number of sets for SET OF.

 *

 * @param s stream

 * @param number number of sets

 *

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

 */

BOOL per_write_number_of_sets(wStream* s, BYTE number)

{

  if (!Stream_EnsureRemainingCapacity(s, 1))

    return FALSE;

  Stream_Write_UINT8(s, number);

  return TRUE;

}

/**

 * Read PER padding with zeros.

 *

 * @param s A stream to read from

 * @param length the data to write

 *

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

 */

BOOL per_read_padding(wStream* s, UINT16 length)

{

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

    return FALSE;

  Stream_Seek(s, length);

  return TRUE;

}

/**

 * Write PER padding with zeros.

 * @param s A stream to write to

 * @param length the data to write

 *

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

 */

BOOL per_write_padding(wStream* s, UINT16 length)

{

  if (!Stream_EnsureRemainingCapacity(s, length))

    return FALSE;

  Stream_Zero(s, length);

  return TRUE;

}

/**

 * Read PER INTEGER.

 * @param s stream

 * @param integer integer

 *

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

 */

BOOL per_read_integer(wStream* s, UINT32* integer)

{

  UINT16 length = 0;

  WINPR_ASSERT(integer);

  if (!per_read_length(s, &length))

    return FALSE;

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

    return FALSE;

  if (length == 0)

    *integer = 0;

  else if (length == 1)

    Stream_Read_UINT8(s, *integer);

  else if (length == 2)

    Stream_Read_UINT16_BE(s, *integer);

  else

    return FALSE;

  return TRUE;

}

/**

 * Write PER INTEGER.

 * @param s stream

 * @param integer integer

 *

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

 */

BOOL per_write_integer(wStream* s, UINT32 integer)

{

  if (integer <= UINT8_MAX)

  {

    if (!per_write_length(s, 1))

      return FALSE;

    if (!Stream_EnsureRemainingCapacity(s, 1))

      return FALSE;

    Stream_Write_UINT8(s, integer);

  }

  else if (integer <= UINT16_MAX)

  {

    if (!per_write_length(s, 2))

      return FALSE;

    if (!Stream_EnsureRemainingCapacity(s, 2))

      return FALSE;

    Stream_Write_UINT16_BE(s, integer);

  }

  else if (integer <= UINT32_MAX)

  {

    if (!per_write_length(s, 4))

      return FALSE;

    if (!Stream_EnsureRemainingCapacity(s, 4))

      return FALSE;

    Stream_Write_UINT32_BE(s, integer);

  }

  return TRUE;

}

/**

 * Read PER INTEGER (UINT16).

 *

 * @param s The stream to read from

 * @param integer The integer result variable pointer, must not be NULL

 * @param min minimum value

 *

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

 */

BOOL per_read_integer16(wStream* s, UINT16* integer, UINT16 min)

{

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

    return FALSE;

  Stream_Read_UINT16_BE(s, *integer);

  if (*integer > UINT16_MAX - min)

  {

    WLog_WARN(TAG, "PER uint16 invalid value %" PRIu16 " > %" PRIu16, *integer,

              UINT16_MAX - min);

    return FALSE;

  }

  *integer += min;

  return TRUE;

}

/**

 * Write PER INTEGER (UINT16).

 * @param s stream

 * @param integer integer

 * @param min minimum value

 *

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

 */

BOOL per_write_integer16(wStream* s, UINT16 integer, UINT16 min)

{

  if (!Stream_EnsureRemainingCapacity(s, 2))

    return FALSE;

  Stream_Write_UINT16_BE(s, integer - min);

  return TRUE;

}

/**

 * Read PER ENUMERATED.

 *

 * @param s The stream to read from

 * @param enumerated enumerated result variable, must not be NULL

 * @param count enumeration count

 *

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

 */

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

{

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

    return FALSE;

  WINPR_ASSERT(enumerated);

  Stream_Read_UINT8(s, *enumerated);

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

  if (*enumerated + 1 > count)

  {

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

    return FALSE;

  }

  return TRUE;

}

/**

 * Write PER ENUMERATED.

 *

 * @param s The stream to write to

 * @param enumerated enumerated

 * @param count enumeration count

 *

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

 */

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

{

  if (!Stream_EnsureRemainingCapacity(s, 1))

    return FALSE;

  Stream_Write_UINT8(s, enumerated);

  return TRUE;

}

static BOOL per_check_oid_and_log_mismatch(const BYTE* got, const BYTE* expect, size_t length)

{

  if (memcmp(got, expect, length) == 0)

  {

    return TRUE;

  }

  else

  {

    char* got_str = winpr_BinToHexString(got, length, TRUE);

    char* expect_str = winpr_BinToHexString(expect, length, TRUE);

    WLog_WARN(TAG, "PER OID mismatch, got %s, expected %s", got_str, expect_str);

    free(got_str);

    free(expect_str);

    return FALSE;

  }

}

/**

 * Read PER OBJECT_IDENTIFIER (OID).

 *

 * @param s The stream to read from

 * @param oid object identifier (OID)

 * @warning It works correctly only for limited set of OIDs.

 *

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

 */

BOOL per_read_object_identifier(wStream* s, const BYTE oid[6])

{

  BYTE t12 = 0;

  UINT16 length = 0;

  BYTE a_oid[6] = { 0 };

  if (!per_read_length(s, &length))

    return FALSE;

  if (length != 5)

  {

    WLog_WARN(TAG, "PER length, got %" PRIu16 ", expected 5", length);

    return FALSE;

  }

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

    return FALSE;

  Stream_Read_UINT8(s, t12); /* first two tuples */

  a_oid[0] = t12 / 40;

  a_oid[1] = t12 % 40;

  Stream_Read_UINT8(s, a_oid[2]); /* tuple 3 */

  Stream_Read_UINT8(s, a_oid[3]); /* tuple 4 */

  Stream_Read_UINT8(s, a_oid[4]); /* tuple 5 */

  Stream_Read_UINT8(s, a_oid[5]); /* tuple 6 */

  return per_check_oid_and_log_mismatch(a_oid, oid, sizeof(a_oid));

}

/**

 * Write PER OBJECT_IDENTIFIER (OID)

 * @param s stream

 * @param oid object identifier (oid)

 * @warning It works correctly only for limited set of OIDs.

 *

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

 */

BOOL per_write_object_identifier(wStream* s, const BYTE oid[6])

{

  BYTE t12 = oid[0] * 40 + oid[1];

  if (!Stream_EnsureRemainingCapacity(s, 6))

    return FALSE;

  Stream_Write_UINT8(s, 5);      /* length */

  Stream_Write_UINT8(s, t12);    /* first two tuples */

  Stream_Write_UINT8(s, oid[2]); /* tuple 3 */

  Stream_Write_UINT8(s, oid[3]); /* tuple 4 */

  Stream_Write_UINT8(s, oid[4]); /* tuple 5 */

  Stream_Write_UINT8(s, oid[5]); /* tuple 6 */

  return TRUE;

}

/**

 * Write PER string.

 * @param s stream

 * @param str string

 * @param length string length

 */

static void per_write_string(wStream* s, BYTE* str, int length)

{

  for (int i = 0; i < length; i++)

    Stream_Write_UINT8(s, str[i]);

}

/**

 * Read PER OCTET_STRING.

 *

 * @param s The stream to read from

 * @param oct_str octet string

 * @param length string length

 * @param min minimum length

 *

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

 */

BOOL per_read_octet_string(wStream* s, const BYTE* oct_str, UINT16 length, UINT16 min)

{

  UINT16 mlength = 0;

  if (!per_read_length(s, &mlength))

    return FALSE;

  if (mlength + min != length)

  {

    WLog_ERR(TAG, "length mismatch: %" PRIu16 "!= %" PRIu16, mlength + min, length);

    return FALSE;

  }

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

    return FALSE;

  const BYTE* a_oct_str = Stream_ConstPointer(s);

  Stream_Seek(s, length);

  return per_check_oid_and_log_mismatch(a_oct_str, oct_str, length);

}

/**

 * Write PER OCTET_STRING

 * @param s stream

 * @param oct_str octet string

 * @param length string length

 * @param min minimum string length

 *

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

 */

BOOL per_write_octet_string(wStream* s, const BYTE* oct_str, UINT16 length, UINT16 min)

{

  UINT16 mlength = 0;

  mlength = (length >= min) ? length - min : min;

  if (!per_write_length(s, mlength))

    return FALSE;

  if (!Stream_EnsureRemainingCapacity(s, length))

    return FALSE;

  for (UINT16 i = 0; i < length; i++)

    Stream_Write_UINT8(s, oct_str[i]);

  return TRUE;

}

/**

 * Read PER NumericString.

 * @param s stream

 * @param min minimum string length

 *

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

 */

BOOL per_read_numeric_string(wStream* s, UINT16 min)

{

  size_t length = 0;

  UINT16 mlength = 0;

  if (!per_read_length(s, &mlength))

    return FALSE;

  length = (mlength + min + 1) / 2;

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

    return FALSE;

  Stream_Seek(s, length);

  return TRUE;

}

/**

 * Write PER NumericString.

 * @param s stream

 * @param num_str numeric string

 * @param length string length

 * @param min minimum string length

 *

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

 */

BOOL per_write_numeric_string(wStream* s, const BYTE* num_str, UINT16 length, UINT16 min)

{

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

  const UINT16 mlength = (length >= min) ? length - min : min;

  if (!per_write_length(s, mlength))

    return FALSE;

  if (!Stream_EnsureRemainingCapacity(s, length))

    return FALSE;

  for (UINT16 i = 0; i < length; i += 2)

  {

    BYTE c1 = num_str[i];

    BYTE c2 = ((i + 1) < length) ? num_str[i + 1] : 0x30;

    if ((c1 < 0x30) || (c2 < 0x30))

      return FALSE;

    c1 = (c1 - 0x30) % 10;

    c2 = (c2 - 0x30) % 10;

    const BYTE num = (c1 << 4) | c2;

    Stream_Write_UINT8(s, num); /* string */

  }

  return TRUE;

}