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11b8d5ef91
To reduce the number of copies of boilerplate code throughout the tree, this patch implements generic glue for the SHA-256 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 (sha256_block_fn)(struct sha256_state *sst, u8 const *src, int blocks) and pass it to the SHA-256 base functions. For easy casting between the prototype above and existing block functions that take a 'u32 state[]' as their first argument, the 'state' member of struct sha256_state is moved to the base of the struct. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
128 lines
3 KiB
C
128 lines
3 KiB
C
/*
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* sha256_base.h - core logic for SHA-256 implementations
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*
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* Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <crypto/internal/hash.h>
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#include <crypto/sha.h>
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#include <linux/crypto.h>
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#include <linux/module.h>
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#include <asm/unaligned.h>
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typedef void (sha256_block_fn)(struct sha256_state *sst, u8 const *src,
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int blocks);
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static inline int sha224_base_init(struct shash_desc *desc)
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{
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struct sha256_state *sctx = shash_desc_ctx(desc);
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sctx->state[0] = SHA224_H0;
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sctx->state[1] = SHA224_H1;
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sctx->state[2] = SHA224_H2;
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sctx->state[3] = SHA224_H3;
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sctx->state[4] = SHA224_H4;
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sctx->state[5] = SHA224_H5;
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sctx->state[6] = SHA224_H6;
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sctx->state[7] = SHA224_H7;
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sctx->count = 0;
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return 0;
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}
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static inline int sha256_base_init(struct shash_desc *desc)
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{
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struct sha256_state *sctx = shash_desc_ctx(desc);
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sctx->state[0] = SHA256_H0;
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sctx->state[1] = SHA256_H1;
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sctx->state[2] = SHA256_H2;
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sctx->state[3] = SHA256_H3;
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sctx->state[4] = SHA256_H4;
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sctx->state[5] = SHA256_H5;
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sctx->state[6] = SHA256_H6;
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sctx->state[7] = SHA256_H7;
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sctx->count = 0;
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return 0;
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}
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static inline int sha256_base_do_update(struct shash_desc *desc,
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const u8 *data,
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unsigned int len,
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sha256_block_fn *block_fn)
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{
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struct sha256_state *sctx = shash_desc_ctx(desc);
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unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
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sctx->count += len;
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if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) {
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int blocks;
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if (partial) {
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int p = SHA256_BLOCK_SIZE - partial;
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memcpy(sctx->buf + partial, data, p);
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data += p;
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len -= p;
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block_fn(sctx, sctx->buf, 1);
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}
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blocks = len / SHA256_BLOCK_SIZE;
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len %= SHA256_BLOCK_SIZE;
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if (blocks) {
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block_fn(sctx, data, blocks);
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data += blocks * SHA256_BLOCK_SIZE;
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}
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partial = 0;
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}
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if (len)
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memcpy(sctx->buf + partial, data, len);
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return 0;
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}
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static inline int sha256_base_do_finalize(struct shash_desc *desc,
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sha256_block_fn *block_fn)
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{
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const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64);
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struct sha256_state *sctx = shash_desc_ctx(desc);
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__be64 *bits = (__be64 *)(sctx->buf + bit_offset);
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unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
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sctx->buf[partial++] = 0x80;
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if (partial > bit_offset) {
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memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial);
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partial = 0;
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block_fn(sctx, sctx->buf, 1);
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}
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memset(sctx->buf + partial, 0x0, bit_offset - partial);
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*bits = cpu_to_be64(sctx->count << 3);
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block_fn(sctx, sctx->buf, 1);
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return 0;
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}
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static inline int sha256_base_finish(struct shash_desc *desc, u8 *out)
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{
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unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
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struct sha256_state *sctx = shash_desc_ctx(desc);
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__be32 *digest = (__be32 *)out;
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int i;
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for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
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put_unaligned_be32(sctx->state[i], digest++);
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*sctx = (struct sha256_state){};
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return 0;
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}
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