/*
 * Copyright (C) 2011-2012 Free Software Foundation, Inc.
 * Portions Copyright (C) 2001 Niels Moeller
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of GNUTLS.
 *
 * The GNUTLS library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * 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.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>
 *
 */

#include "gnutls_int.h"
#include "hash_int.h"
#include "errors.h"
#include <nettle/sha.h>
#include <nettle/hmac.h>
#include <nettle/macros.h>
#include "aes-padlock.h"
#include <assert.h>
#include "sha-padlock.h"
#include "x86-common.h"

#ifdef HAVE_LIBNETTLE

typedef void (*update_func)(void *, size_t, const uint8_t *);
typedef void (*digest_func)(void *, size_t, uint8_t *);
typedef void (*set_key_func)(void *, size_t, const uint8_t *);
typedef void (*init_func)(void *);

struct padlock_hash_ctx {
	union {
		struct sha1_ctx sha1;
		struct sha224_ctx sha224;
		struct sha256_ctx sha256;
		struct sha384_ctx sha384;
		struct sha512_ctx sha512;
	} ctx;
	void *ctx_ptr;
	gnutls_digest_algorithm_t algo;
	size_t length;
	update_func update;
	digest_func digest;
	init_func init;
};

static int wrap_padlock_hash_update(void *_ctx, const void *text,
				    size_t textsize)
{
	struct padlock_hash_ctx *ctx = _ctx;

	ctx->update(ctx->ctx_ptr, textsize, text);

	return GNUTLS_E_SUCCESS;
}

static void wrap_padlock_hash_deinit(void *hd)
{
	gnutls_free(hd);
}

#define MD1_INCR(c) (c->count++)
#define SHA1_COMPRESS(ctx, data) \
	(padlock_sha1_blocks((void *)(ctx)->state, data, 1))
#define SHA256_COMPRESS(ctx, data) \
	(padlock_sha256_blocks((void *)(ctx)->state, data, 1))
#define SHA512_COMPRESS(ctx, data) \
	(padlock_sha512_blocks((void *)(ctx)->state, data, 1))

void padlock_sha1_update(struct sha1_ctx *ctx, size_t length,
			 const uint8_t *data)
{
	MD_UPDATE(ctx, length, data, SHA1_COMPRESS, MD1_INCR(ctx));
}

void padlock_sha256_update(struct sha256_ctx *ctx, size_t length,
			   const uint8_t *data)
{
	MD_UPDATE(ctx, length, data, SHA256_COMPRESS, MD1_INCR(ctx));
}

void padlock_sha512_update(struct sha512_ctx *ctx, size_t length,
			   const uint8_t *data)
{
	MD_UPDATE(ctx, length, data, SHA512_COMPRESS, MD_INCR(ctx));
}

static void _nettle_write_be32(unsigned length, uint8_t *dst, uint32_t *src)
{
	unsigned i;
	unsigned words;
	unsigned leftover;

	words = length / 4;
	leftover = length % 4;

	for (i = 0; i < words; i++, dst += 4)
		WRITE_UINT32(dst, src[i]);

	if (leftover) {
		uint32_t word;
		unsigned j = leftover;

		word = src[i];

		switch (leftover) {
		default:
			abort();
		case 3:
			dst[--j] = (word >> 8) & 0xff;
			FALLTHROUGH;
		case 2:
			dst[--j] = (word >> 16) & 0xff;
			FALLTHROUGH;
		case 1:
			dst[--j] = (word >> 24) & 0xff;
		}
	}
}

static void padlock_sha1_digest(struct sha1_ctx *ctx, size_t length,
				uint8_t *digest)
{
	uint64_t bit_count;

	assert(length <= SHA1_DIGEST_SIZE);

	MD_PAD(ctx, 8, SHA1_COMPRESS);

	/* There are 512 = 2^9 bits in one block */
	bit_count = (ctx->count << 9) | (ctx->index << 3);

	/* append the 64 bit count */
	WRITE_UINT64(ctx->block + (SHA1_BLOCK_SIZE - 8), bit_count);
	SHA1_COMPRESS(ctx, ctx->block);

	_nettle_write_be32(length, digest, ctx->state);
}

static void padlock_sha256_digest(struct sha256_ctx *ctx, size_t length,
				  uint8_t *digest)
{
	uint64_t bit_count;

	assert(length <= SHA256_DIGEST_SIZE);

	MD_PAD(ctx, 8, SHA256_COMPRESS);

	/* There are 512 = 2^9 bits in one block */
	bit_count = (ctx->count << 9) | (ctx->index << 3);

	/* This is slightly inefficient, as the numbers are converted to
	   big-endian format, and will be converted back by the compression
	   function. It's probably not worth the effort to fix this. */
	WRITE_UINT64(ctx->block + (SHA256_BLOCK_SIZE - 8), bit_count);
	SHA256_COMPRESS(ctx, ctx->block);

	_nettle_write_be32(length, digest, ctx->state);
}

static void padlock_sha512_digest(struct sha512_ctx *ctx, size_t length,
				  uint8_t *digest)
{
	uint64_t high, low;

	unsigned i;
	unsigned words;
	unsigned leftover;

	assert(length <= SHA512_DIGEST_SIZE);

	MD_PAD(ctx, 16, SHA512_COMPRESS);

	/* There are 1024 = 2^10 bits in one block */
	high = (ctx->count_high << 10) | (ctx->count_low >> 54);
	low = (ctx->count_low << 10) | (ctx->index << 3);

	/* This is slightly inefficient, as the numbers are converted to
	   big-endian format, and will be converted back by the compression
	   function. It's probably not worth the effort to fix this. */
	WRITE_UINT64(ctx->block + (SHA512_DATA_SIZE - 16), high);
	WRITE_UINT64(ctx->block + (SHA512_DATA_SIZE - 8), low);
	SHA512_COMPRESS(ctx, ctx->block);

	words = length / 8;
	leftover = length % 8;

	for (i = 0; i < words; i++, digest += 8)
		WRITE_UINT64(digest, ctx->state[i]);

	if (leftover) {
		/* Truncate to the right size */
		uint64_t word = ctx->state[i] >> (8 * (8 - leftover));

		do {
			digest[--leftover] = word & 0xff;
			word >>= 8;
		} while (leftover);
	}
}

static int _ctx_init(gnutls_digest_algorithm_t algo,
		     struct padlock_hash_ctx *ctx)
{
	switch (algo) {
	case GNUTLS_DIG_SHA1:
		sha1_init(&ctx->ctx.sha1);
		ctx->update = (update_func)padlock_sha1_update;
		ctx->digest = (digest_func)padlock_sha1_digest;
		ctx->init = (init_func)sha1_init;
		ctx->ctx_ptr = &ctx->ctx.sha1;
		ctx->length = SHA1_DIGEST_SIZE;
		break;
	case GNUTLS_DIG_SHA224:
		sha224_init(&ctx->ctx.sha224);
		ctx->update = (update_func)padlock_sha256_update;
		ctx->digest = (digest_func)padlock_sha256_digest;
		ctx->init = (init_func)sha224_init;
		ctx->ctx_ptr = &ctx->ctx.sha224;
		ctx->length = SHA224_DIGEST_SIZE;
		break;
	case GNUTLS_DIG_SHA256:
		sha256_init(&ctx->ctx.sha256);
		ctx->update = (update_func)padlock_sha256_update;
		ctx->digest = (digest_func)padlock_sha256_digest;
		ctx->init = (init_func)sha256_init;
		ctx->ctx_ptr = &ctx->ctx.sha256;
		ctx->length = SHA256_DIGEST_SIZE;
		break;
	case GNUTLS_DIG_SHA384:
		sha384_init(&ctx->ctx.sha384);
		ctx->update = (update_func)padlock_sha512_update;
		ctx->digest = (digest_func)padlock_sha512_digest;
		ctx->init = (init_func)sha384_init;
		ctx->ctx_ptr = &ctx->ctx.sha384;
		ctx->length = SHA384_DIGEST_SIZE;
		break;
	case GNUTLS_DIG_SHA512:
		sha512_init(&ctx->ctx.sha512);
		ctx->update = (update_func)padlock_sha512_update;
		ctx->digest = (digest_func)padlock_sha512_digest;
		ctx->init = (init_func)sha512_init;
		ctx->ctx_ptr = &ctx->ctx.sha512;
		ctx->length = SHA512_DIGEST_SIZE;
		break;
	default:
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	return 0;
}

static int wrap_padlock_hash_init(gnutls_digest_algorithm_t algo, void **_ctx)
{
	struct padlock_hash_ctx *ctx;
	int ret;

	ctx = gnutls_malloc(sizeof(struct padlock_hash_ctx));
	if (ctx == NULL) {
		gnutls_assert();
		return GNUTLS_E_MEMORY_ERROR;
	}

	ctx->algo = algo;

	if ((ret = _ctx_init(algo, ctx)) < 0) {
		gnutls_assert();
		return ret;
	}

	*_ctx = ctx;

	return 0;
}

static void *wrap_padlock_hash_copy(const void *_ctx)
{
	struct padlock_hash_ctx *new_ctx;
	const struct padlock_hash_ctx *ctx = _ctx;
	ptrdiff_t off = (uint8_t *)ctx->ctx_ptr - (uint8_t *)(&ctx->ctx);

	new_ctx = gnutls_malloc(sizeof(struct padlock_hash_ctx));
	if (new_ctx == NULL) {
		gnutls_assert();
		return NULL;
	}

	memcpy(new_ctx, ctx, sizeof(*new_ctx));
	new_ctx->ctx_ptr = (uint8_t *)&new_ctx->ctx + off;

	return new_ctx;
}

static int wrap_padlock_hash_output(void *src_ctx, void *digest,
				    size_t digestsize)
{
	struct padlock_hash_ctx *ctx;
	ctx = src_ctx;

	if (digestsize < ctx->length)
		return gnutls_assert_val(GNUTLS_E_SHORT_MEMORY_BUFFER);

	ctx->digest(ctx->ctx_ptr, digestsize, digest);

	ctx->init(ctx->ctx_ptr);

	return 0;
}

int wrap_padlock_hash_fast(gnutls_digest_algorithm_t algo, const void *text,
			   size_t text_size, void *digest)
{
	if (text_size == 0 && text == NULL)
		text = digest;
	if (algo == GNUTLS_DIG_SHA1) {
		uint32_t iv[5] = {
			0x67452301UL, 0xEFCDAB89UL, 0x98BADCFEUL,
			0x10325476UL, 0xC3D2E1F0UL,
		};
		padlock_sha1_oneshot(iv, text, text_size);
		_nettle_write_be32(20, digest, iv);
	} else if (algo == GNUTLS_DIG_SHA256) {
		uint32_t iv[8] = {
			0x6a09e667UL, 0xbb67ae85UL, 0x3c6ef372UL, 0xa54ff53aUL,
			0x510e527fUL, 0x9b05688cUL, 0x1f83d9abUL, 0x5be0cd19UL,
		};
		padlock_sha256_oneshot(iv, text, text_size);
		_nettle_write_be32(32, digest, iv);
	} else {
		struct padlock_hash_ctx ctx;
		int ret;

		ret = _ctx_init(algo, &ctx);
		if (ret < 0)
			return gnutls_assert_val(ret);
		ctx.algo = algo;

		wrap_padlock_hash_update(&ctx, text, text_size);

		wrap_padlock_hash_output(&ctx, digest, ctx.length);
	}

	return 0;
}

const struct nettle_hash padlock_sha1 =
	NN_HASH(sha1, padlock_sha1_update, padlock_sha1_digest, SHA1);
const struct nettle_hash padlock_sha224 =
	NN_HASH(sha224, padlock_sha256_update, padlock_sha256_digest, SHA224);
const struct nettle_hash padlock_sha256 =
	NN_HASH(sha256, padlock_sha256_update, padlock_sha256_digest, SHA256);
const struct nettle_hash padlock_sha384 =
	NN_HASH(sha384, padlock_sha512_update, padlock_sha512_digest, SHA384);
const struct nettle_hash padlock_sha512 =
	NN_HASH(sha512, padlock_sha512_update, padlock_sha512_digest, SHA512);

const gnutls_crypto_digest_st _gnutls_sha_padlock_oneshot = {
	.init = NULL,
	.hash = NULL,
	.output = NULL,
	.deinit = NULL,
	.fast = wrap_padlock_hash_fast
};

const gnutls_crypto_digest_st _gnutls_sha_padlock = {
	.init = wrap_padlock_hash_init,
	.hash = wrap_padlock_hash_update,
	.output = wrap_padlock_hash_output,
	.copy = wrap_padlock_hash_copy,
	.deinit = wrap_padlock_hash_deinit,
	.fast = wrap_padlock_hash_fast,
};

#endif /* HAVE_LIBNETTLE */
