From 11b8d5ef91388162103bf28f2e9d6dfd400d192d Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 9 Apr 2015 12:55:34 +0200 Subject: [PATCH] crypto: sha256 - implement base layer for SHA-256 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 Signed-off-by: Herbert Xu --- include/crypto/sha.h | 2 +- include/crypto/sha256_base.h | 128 +++++++++++++++++++++++++++++++++++ 2 files changed, 129 insertions(+), 1 deletion(-) create mode 100644 include/crypto/sha256_base.h diff --git a/include/crypto/sha.h b/include/crypto/sha.h index a9aad8e63f43..a75bc80cc776 100644 --- a/include/crypto/sha.h +++ b/include/crypto/sha.h @@ -71,8 +71,8 @@ struct sha1_state { }; struct sha256_state { - u64 count; u32 state[SHA256_DIGEST_SIZE / 4]; + u64 count; u8 buf[SHA256_BLOCK_SIZE]; }; diff --git a/include/crypto/sha256_base.h b/include/crypto/sha256_base.h new file mode 100644 index 000000000000..d1f2195bb7de --- /dev/null +++ b/include/crypto/sha256_base.h @@ -0,0 +1,128 @@ +/* + * sha256_base.h - core logic for SHA-256 implementations + * + * Copyright (C) 2015 Linaro Ltd + * + * 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 +#include +#include +#include + +#include + +typedef void (sha256_block_fn)(struct sha256_state *sst, u8 const *src, + int blocks); + +static inline int sha224_base_init(struct shash_desc *desc) +{ + struct sha256_state *sctx = shash_desc_ctx(desc); + + sctx->state[0] = SHA224_H0; + sctx->state[1] = SHA224_H1; + sctx->state[2] = SHA224_H2; + sctx->state[3] = SHA224_H3; + sctx->state[4] = SHA224_H4; + sctx->state[5] = SHA224_H5; + sctx->state[6] = SHA224_H6; + sctx->state[7] = SHA224_H7; + sctx->count = 0; + + return 0; +} + +static inline int sha256_base_init(struct shash_desc *desc) +{ + struct sha256_state *sctx = shash_desc_ctx(desc); + + sctx->state[0] = SHA256_H0; + sctx->state[1] = SHA256_H1; + sctx->state[2] = SHA256_H2; + sctx->state[3] = SHA256_H3; + sctx->state[4] = SHA256_H4; + sctx->state[5] = SHA256_H5; + sctx->state[6] = SHA256_H6; + sctx->state[7] = SHA256_H7; + sctx->count = 0; + + return 0; +} + +static inline int sha256_base_do_update(struct shash_desc *desc, + const u8 *data, + unsigned int len, + sha256_block_fn *block_fn) +{ + struct sha256_state *sctx = shash_desc_ctx(desc); + unsigned int partial = sctx->count % SHA256_BLOCK_SIZE; + + sctx->count += len; + + if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) { + int blocks; + + if (partial) { + int p = SHA256_BLOCK_SIZE - partial; + + memcpy(sctx->buf + partial, data, p); + data += p; + len -= p; + + block_fn(sctx, sctx->buf, 1); + } + + blocks = len / SHA256_BLOCK_SIZE; + len %= SHA256_BLOCK_SIZE; + + if (blocks) { + block_fn(sctx, data, blocks); + data += blocks * SHA256_BLOCK_SIZE; + } + partial = 0; + } + if (len) + memcpy(sctx->buf + partial, data, len); + + return 0; +} + +static inline int sha256_base_do_finalize(struct shash_desc *desc, + sha256_block_fn *block_fn) +{ + const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64); + struct sha256_state *sctx = shash_desc_ctx(desc); + __be64 *bits = (__be64 *)(sctx->buf + bit_offset); + unsigned int partial = sctx->count % SHA256_BLOCK_SIZE; + + sctx->buf[partial++] = 0x80; + if (partial > bit_offset) { + memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial); + partial = 0; + + block_fn(sctx, sctx->buf, 1); + } + + memset(sctx->buf + partial, 0x0, bit_offset - partial); + *bits = cpu_to_be64(sctx->count << 3); + block_fn(sctx, sctx->buf, 1); + + return 0; +} + +static inline int sha256_base_finish(struct shash_desc *desc, u8 *out) +{ + unsigned int digest_size = crypto_shash_digestsize(desc->tfm); + struct sha256_state *sctx = shash_desc_ctx(desc); + __be32 *digest = (__be32 *)out; + int i; + + for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32)) + put_unaligned_be32(sctx->state[i], digest++); + + *sctx = (struct sha256_state){}; + return 0; +} -- GitLab