/**

 * 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.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <freerdp/crypto/per.h>

/**

 * Read PER length.

 * @param s stream

 * @param length length

 * @return

 */

BOOL per_read_length(wStream* s, UINT16* length)

{

	BYTE byte;

	if (Stream_GetRemainingLength(s) < 1)

		return FALSE;

	Stream_Read_UINT8(s, byte);

	if (byte & 0x80)

	{

		if (Stream_GetRemainingLength(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

 */

void per_write_length(wStream* s, int length)

{

	if (length > 0x7F)

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

	else

		Stream_Write_UINT8(s, length);

}

/**

 * Read PER choice.

 * @param s stream

 * @param choice choice

 * @return

 */

BOOL per_read_choice(wStream* s, BYTE* choice)

{

	if (Stream_GetRemainingLength(s) < 1)

		return FALSE;

	Stream_Read_UINT8(s, *choice);

	return TRUE;

}

/**

 * Write PER CHOICE.

 * @param s stream

 * @param choice index of chosen field

 */

void per_write_choice(wStream* s, BYTE choice)

{

	Stream_Write_UINT8(s, choice);

}

/**

 * Read PER selection.

 * @param s stream

 * @param selection selection

 * @return

 */

BOOL per_read_selection(wStream* s, BYTE* selection)

{

	if (Stream_GetRemainingLength(s) < 1)

		return FALSE;

	Stream_Read_UINT8(s, *selection);

	return TRUE;

}

/**

 * Write PER selection for OPTIONAL fields.

 * @param s stream

 * @param selection bit map of selected fields

 */

void per_write_selection(wStream* s, BYTE selection)

{

	Stream_Write_UINT8(s, selection);

}

/**

 * Read PER number of sets.

 * @param s stream

 * @param number number of sets

 * @return

 */

BOOL per_read_number_of_sets(wStream* s, BYTE* number)

{

	if (Stream_GetRemainingLength(s) < 1)

		return FALSE;

	Stream_Read_UINT8(s, *number);

	return TRUE;

}

/**

 * Write PER number of sets for SET OF.

 * @param s stream

 * @param number number of sets

 */

void per_write_number_of_sets(wStream* s, BYTE number)

{

	Stream_Write_UINT8(s, number);

}

/**

 * Read PER padding with zeros.

 * @param s stream

 * @param length

 */

BOOL per_read_padding(wStream* s, int length)

{

	if (((int) Stream_GetRemainingLength(s)) < length)

		return FALSE;

	Stream_Seek(s, length);

	return TRUE;

}

/**

 * Write PER padding with zeros.

 * @param s stream

 * @param length

 */

void per_write_padding(wStream* s, int length)

{

	int i;

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

		Stream_Write_UINT8(s, 0);

}

/**

 * Read PER INTEGER.

 * @param s stream

 * @param integer integer

 * @return

 */

BOOL per_read_integer(wStream* s, UINT32* integer)

{

	UINT16 length;

	if (!per_read_length(s, &length))

		return FALSE;

	if (Stream_GetRemainingLength(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

 */

void per_write_integer(wStream* s, UINT32 integer)

{

	if (integer <= 0xFF)

	{

		per_write_length(s, 1);

		Stream_Write_UINT8(s, integer);

	}

	else if (integer <= 0xFFFF)

	{

		per_write_length(s, 2);

		Stream_Write_UINT16_BE(s, integer);

	}

	else if (integer <= 0xFFFFFFFF)

	{

		per_write_length(s, 4);

		Stream_Write_UINT32_BE(s, integer);

	}

}

/**

 * Read PER INTEGER (UINT16).

 * @param s stream

 * @param integer integer

 * @param min minimum value

 * @return

 */

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

{

	if (Stream_GetRemainingLength(s) < 2)

		return FALSE;

	Stream_Read_UINT16_BE(s, *integer);

	if (*integer + min > 0xFFFF)

		return FALSE;

	*integer += min;

	return TRUE;

}

/**

 * Write PER INTEGER (UINT16).

 * @param s stream

 * @param integer integer

 * @param min minimum value

 */

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

{

	Stream_Write_UINT16_BE(s, integer - min);

}

/**

 * Read PER ENUMERATED.

 * @param s stream

 * @param enumerated enumerated

 * @param count enumeration count

 * @return

 */

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

{

	if (Stream_GetRemainingLength(s) < 1)

		return FALSE;

	Stream_Read_UINT8(s, *enumerated);

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

	if (*enumerated + 1 > count)

		return FALSE;

	return TRUE;

}

/**

 * Write PER ENUMERATED.

 * @param s stream

 * @param enumerated enumerated

 * @param count enumeration count

 * @return

 */

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

{

	Stream_Write_UINT8(s, enumerated);

}

/**

 * Read PER OBJECT_IDENTIFIER (OID).

 * @param s stream

 * @param oid object identifier (OID)

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

 * @return

 */

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

{

	BYTE t12;

	UINT16 length;

	BYTE a_oid[6];

	if (!per_read_length(s, &length))

		return FALSE;

	if (length != 5)

		return FALSE;

	if (Stream_GetRemainingLength(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 */

	if ((a_oid[0] == oid[0]) && (a_oid[1] == oid[1]) &&

		(a_oid[2] == oid[2]) && (a_oid[3] == oid[3]) &&

		(a_oid[4] == oid[4]) && (a_oid[5] == oid[5]))

	{

		return TRUE;

	}

	else

	{

		return FALSE;

	}

}

/**

 * Write PER OBJECT_IDENTIFIER (OID)

 * @param s stream

 * @param oid object identifier (oid)

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

 */

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

{

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

	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 */

}

/**

 * Write PER string.

 * @param s stream

 * @param str string

 * @param length string length

 */

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

{

	int i;

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

		Stream_Write_UINT8(s, str[i]);

}

/**

 * Read PER OCTET_STRING.

 * @param s stream

 * @param oct_str octet string

 * @param length string length

 * @param min minimum length

 * @return

 */

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

{

	int i;

	UINT16 mlength;

	BYTE* a_oct_str;

	if (!per_read_length(s, &mlength))

		return FALSE;

	if (mlength + min != length)

		return FALSE;

	if (((int) Stream_GetRemainingLength(s)) < length)

		return FALSE;

	a_oct_str = Stream_Pointer(s);

	Stream_Seek(s, length);

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

	{

		if (a_oct_str[i] != oct_str[i])

			return FALSE;

	}

	return TRUE;

}

/**

 * Write PER OCTET_STRING

 * @param s stream

 * @param oct_str octet string

 * @param length string length

 * @param min minimum string length

 */

void per_write_octet_string(wStream* s, BYTE* oct_str, int length, int min)

{

	int i;

	int mlength;

	mlength = (length - min >= 0) ? length - min : min;

	per_write_length(s, mlength);

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

		Stream_Write_UINT8(s, oct_str[i]);

}

/**

 * Read PER NumericString.

 * @param s stream

 * @param num_str numeric string

 * @param length string length

 * @param min minimum string length

 */

BOOL per_read_numeric_string(wStream* s, int min)

{

	int length;

	UINT16 mlength;

	if (!per_read_length(s, &mlength))

		return FALSE;

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

	if (((int) Stream_GetRemainingLength(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

 */

void per_write_numeric_string(wStream* s, BYTE* num_str, int length, int min)

{

	int i;

	int mlength;

	BYTE num, c1, c2;

	mlength = (length - min >= 0) ? length - min : min;

	per_write_length(s, mlength);

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

	{

		c1 = num_str[i];

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

		c1 = (c1 - 0x30) % 10;

		c2 = (c2 - 0x30) % 10;

		num = (c1 << 4) | c2;

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

	}

}