xz/src/liblzma/check/check.c

///////////////////////////////////////////////////////////////////////////////
//
/// \file       check.c
/// \brief      Check sizes
//
//  This code has been put into the public domain.
//
//  This library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
//
///////////////////////////////////////////////////////////////////////////////

#include "check.h"


extern LZMA_API lzma_bool
lzma_check_is_supported(lzma_check type)
{
	if ((unsigned)(type) > LZMA_CHECK_ID_MAX)
		return false;

	static const lzma_bool available_checks[LZMA_CHECK_ID_MAX + 1] = {
		true,   // LZMA_CHECK_NONE

#ifdef HAVE_CHECK_CRC32
		true,
#else
		false,
#endif

		false,  // Reserved
		false,  // Reserved

#ifdef HAVE_CHECK_CRC64
		true,
#else
		false,
#endif

		false,  // Reserved
		false,  // Reserved
		false,  // Reserved
		false,  // Reserved
		false,  // Reserved

#ifdef HAVE_CHECK_SHA256
		true,
#else
		false,
#endif

		false,  // Reserved
		false,  // Reserved
		false,  // Reserved
		false,  // Reserved
		false,  // Reserved
	};

	return available_checks[(unsigned)(type)];
}


extern LZMA_API uint32_t
lzma_check_size(lzma_check type)
{
	if ((unsigned)(type) > LZMA_CHECK_ID_MAX)
		return UINT32_MAX;

	// See file-format.txt section 2.1.1.2.
	static const uint8_t check_sizes[LZMA_CHECK_ID_MAX + 1] = {
		0,
		4, 4, 4,
		8, 8, 8,
		16, 16, 16,
		32, 32, 32,
		64, 64, 64
	};

	return check_sizes[(unsigned)(type)];
}


extern void
lzma_check_init(lzma_check_state *check, lzma_check type)
{
	switch (type) {
	case LZMA_CHECK_NONE:
		break;

#ifdef HAVE_CHECK_CRC32
	case LZMA_CHECK_CRC32:
		check->state.crc32 = 0;
		break;
#endif

#ifdef HAVE_CHECK_CRC64
	case LZMA_CHECK_CRC64:
		check->state.crc64 = 0;
		break;
#endif

#ifdef HAVE_CHECK_SHA256
	case LZMA_CHECK_SHA256:
		lzma_sha256_init(check);
		break;
#endif

	default:
		break;
	}

	return;
}


extern void
lzma_check_update(lzma_check_state *check, lzma_check type,
		const uint8_t *buf, size_t size)
{
	switch (type) {
#ifdef HAVE_CHECK_CRC32
	case LZMA_CHECK_CRC32:
		check->state.crc32 = lzma_crc32(buf, size, check->state.crc32);
		break;
#endif

#ifdef HAVE_CHECK_CRC64
	case LZMA_CHECK_CRC64:
		check->state.crc64 = lzma_crc64(buf, size, check->state.crc64);
		break;
#endif

#ifdef HAVE_CHECK_SHA256
	case LZMA_CHECK_SHA256:
		lzma_sha256_update(buf, size, check);
		break;
#endif

	default:
		break;
	}

	return;
}


extern void
lzma_check_finish(lzma_check_state *check, lzma_check type)
{
	switch (type) {
#ifdef HAVE_CHECK_CRC32
	case LZMA_CHECK_CRC32:
		check->buffer.u32[0] = integer_le_32(check->state.crc32);
		break;
#endif

#ifdef HAVE_CHECK_CRC64
	case LZMA_CHECK_CRC64:
		check->buffer.u64[0] = integer_le_64(check->state.crc64);
		break;
#endif

#ifdef HAVE_CHECK_SHA256
	case LZMA_CHECK_SHA256:
		lzma_sha256_finish(check);
		break;
#endif

	default:
		break;
	}

	return;
}