// SHA-224. Adapted from LibTomCrypt. This code is Public Domain
#include "hash.h"

#include <blue/core/hash.h>
#include <string.h>

extern void z__b_sha2_256_update(
	struct b_hash_ctx *md, const void *src, size_t inlen);
extern void z__b_sha2_256_finish(struct b_hash_ctx *md, void *out, size_t max);

static void sha_init(struct b_hash_ctx *md)
{
	md->ctx_state.sha2_256.curlen = 0;
	md->ctx_state.sha2_256.length = 0;
	md->ctx_state.sha2_256.state[0] = 0xc1059ed8UL;
	md->ctx_state.sha2_256.state[1] = 0x367cd507UL;
	md->ctx_state.sha2_256.state[2] = 0x3070dd17UL;
	md->ctx_state.sha2_256.state[3] = 0xf70e5939UL;
	md->ctx_state.sha2_256.state[4] = 0xffc00b31UL;
	md->ctx_state.sha2_256.state[5] = 0x68581511UL;
	md->ctx_state.sha2_256.state[6] = 0x64f98fa7UL;
	md->ctx_state.sha2_256.state[7] = 0xbefa4fa4UL;
}

static void sha_update(struct b_hash_ctx *md, const void *in, size_t inlen)
{
	z__b_sha2_256_update(md, in, inlen);
}

static void sha_finish(struct b_hash_ctx *md, void *out, size_t max)
{
	unsigned char res[B_DIGEST_LENGTH_SHA2_256];
	z__b_sha2_256_finish(md, res, max);
	/* truncate the digest to 224 bits */
	memcpy(out, res, b_min(size_t, max, B_DIGEST_LENGTH_224));
}

struct b_hash_function_ops z__b_sha2_224_ops = {
	.hash_init = sha_init,
	.hash_update = sha_update,
	.hash_finish = sha_finish,
};