hash.c

// SPDX-License-Identifier: MIT


#include <xxhash.h>
#include <openssl/sha.h>
#include <blake2.h>
#include "ondisk_format.h"
#include "messages.h"
#include "libs/crc32c.h"

static int hash_crc32c(const u8* buf, size_t length, u8 *out)
{
	u32 crc = ~0;

	crc = crc32c(~0, buf, length);
	put_unaligned_le32(~crc, out);

	return 0;
}

static int hash_xxhash(const u8* buf, size_t length, u8 *out)
{
	XXH64_hash_t hash;

	hash = XXH64(buf, length, 0);
	put_unaligned_le64(hash, out);

	return 0;
}

static int hash_sha256(const u8* buf, size_t length, u8 *out)
{
	SHA256(buf, length, out);

	return 0;
}

static int hash_blake2b(const u8* buf, size_t length, u8 *out)
{
	blake2b_state S;

	blake2b_init(&S, BTRFS_CSUM_SIZE);
	blake2b_update(&S, buf, length);
	blake2b_final(&S, out, BTRFS_CSUM_SIZE);

	return 0;
}

int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len)
{
	memset(out, 0, BTRFS_CSUM_SIZE);

	switch(csum_type) {
	case BTRFS_CSUM_TYPE_CRC32:
		return hash_crc32c(data, len, out);
	case BTRFS_CSUM_TYPE_XXHASH:
		return hash_xxhash(data, len, out);
	case BTRFS_CSUM_TYPE_SHA256:
		return hash_sha256(data, len, out);
	case BTRFS_CSUM_TYPE_BLAKE2:
		return hash_blake2b(data, len, out);
	default:
		error("unknown csum type: %d\n", csum_type);
		assert(0);
	}
	return -1;
}