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Commit b84a2a0b authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
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crypto: sha512 - implement base layer for SHA-512 



To reduce the number of copies of boilerplate code throughout
the tree, this patch implements generic glue for the SHA-512
algorithm. This allows a specific arch or hardware implementation
to only implement the special handling that it needs.

The users need to supply an implementation of

  void (sha512_block_fn)(struct sha512_state *sst, u8 const *src, int blocks)

and pass it to the SHA-512 base functions. For easy casting between the
prototype above and existing block functions that take a 'u64 state[]'
as their first argument, the 'state' member of struct sha512_state is
moved to the base of the struct.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 11b8d5ef

include/crypto/sha.h

+1 −1
Original line number Diff line number Diff line
@@ -77,8 +77,8 @@ struct sha256_state { 
};



struct sha512_state {

	u64 count[2];

	u64 state[SHA512_DIGEST_SIZE / 8];

	u64 count[2];

	u8 buf[SHA512_BLOCK_SIZE];

};

include/crypto/sha512_base.h

0 → 100644
+131 −0
Original line number Diff line number Diff line 
/*

 * sha512_base.h - core logic for SHA-512 implementations

 *

 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */



#include <crypto/internal/hash.h>

#include <crypto/sha.h>

#include <linux/crypto.h>

#include <linux/module.h>



#include <asm/unaligned.h>



typedef void (sha512_block_fn)(struct sha512_state *sst, u8 const *src,

			       int blocks);



static inline int sha384_base_init(struct shash_desc *desc)

{

	struct sha512_state *sctx = shash_desc_ctx(desc);



	sctx->state[0] = SHA384_H0;

	sctx->state[1] = SHA384_H1;

	sctx->state[2] = SHA384_H2;

	sctx->state[3] = SHA384_H3;

	sctx->state[4] = SHA384_H4;

	sctx->state[5] = SHA384_H5;

	sctx->state[6] = SHA384_H6;

	sctx->state[7] = SHA384_H7;

	sctx->count[0] = sctx->count[1] = 0;



	return 0;

}



static inline int sha512_base_init(struct shash_desc *desc)

{

	struct sha512_state *sctx = shash_desc_ctx(desc);



	sctx->state[0] = SHA512_H0;

	sctx->state[1] = SHA512_H1;

	sctx->state[2] = SHA512_H2;

	sctx->state[3] = SHA512_H3;

	sctx->state[4] = SHA512_H4;

	sctx->state[5] = SHA512_H5;

	sctx->state[6] = SHA512_H6;

	sctx->state[7] = SHA512_H7;

	sctx->count[0] = sctx->count[1] = 0;



	return 0;

}



static inline int sha512_base_do_update(struct shash_desc *desc,

					const u8 *data,

					unsigned int len,

					sha512_block_fn *block_fn)

{

	struct sha512_state *sctx = shash_desc_ctx(desc);

	unsigned int partial = sctx->count[0] % SHA512_BLOCK_SIZE;



	sctx->count[0] += len;

	if (sctx->count[0] < len)

		sctx->count[1]++;



	if (unlikely((partial + len) >= SHA512_BLOCK_SIZE)) {

		int blocks;



		if (partial) {

			int p = SHA512_BLOCK_SIZE - partial;



			memcpy(sctx->buf + partial, data, p);

			data += p;

			len -= p;



			block_fn(sctx, sctx->buf, 1);

		}



		blocks = len / SHA512_BLOCK_SIZE;

		len %= SHA512_BLOCK_SIZE;



		if (blocks) {

			block_fn(sctx, data, blocks);

			data += blocks * SHA512_BLOCK_SIZE;

		}

		partial = 0;

	}

	if (len)

		memcpy(sctx->buf + partial, data, len);



	return 0;

}



static inline int sha512_base_do_finalize(struct shash_desc *desc,

					  sha512_block_fn *block_fn)

{

	const int bit_offset = SHA512_BLOCK_SIZE - sizeof(__be64[2]);

	struct sha512_state *sctx = shash_desc_ctx(desc);

	__be64 *bits = (__be64 *)(sctx->buf + bit_offset);

	unsigned int partial = sctx->count[0] % SHA512_BLOCK_SIZE;



	sctx->buf[partial++] = 0x80;

	if (partial > bit_offset) {

		memset(sctx->buf + partial, 0x0, SHA512_BLOCK_SIZE - partial);

		partial = 0;



		block_fn(sctx, sctx->buf, 1);

	}



	memset(sctx->buf + partial, 0x0, bit_offset - partial);

	bits[0] = cpu_to_be64(sctx->count[1] << 3 | sctx->count[0] >> 61);

	bits[1] = cpu_to_be64(sctx->count[0] << 3);

	block_fn(sctx, sctx->buf, 1);



	return 0;

}



static inline int sha512_base_finish(struct shash_desc *desc, u8 *out)

{

	unsigned int digest_size = crypto_shash_digestsize(desc->tfm);

	struct sha512_state *sctx = shash_desc_ctx(desc);

	__be64 *digest = (__be64 *)out;

	int i;



	for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be64))

		put_unaligned_be64(sctx->state[i], digest++);



	*sctx = (struct sha512_state){};

	return 0;

}