include/crypto/sha1_base.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * sha1_base.h - core logic for SHA-1 implementations
0004  *
0005  * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
0006  */
0007
0008 #ifndef _CRYPTO_SHA1_BASE_H
0009 #define _CRYPTO_SHA1_BASE_H
0010
0011 #include <crypto/internal/hash.h>
0012 #include <crypto/sha1.h>
0013 #include <linux/crypto.h>
0014 #include <linux/module.h>
0015 #include <linux/string.h>
0016
0017 #include <asm/unaligned.h>
0018
0019 typedef void (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks);
0020
0021 static inline int sha1_base_init(struct shash_desc *desc)
0022 {
0023     struct sha1_state *sctx = shash_desc_ctx(desc);
0024
0025     sctx->state[0] = SHA1_H0;
0026     sctx->state[1] = SHA1_H1;
0027     sctx->state[2] = SHA1_H2;
0028     sctx->state[3] = SHA1_H3;
0029     sctx->state[4] = SHA1_H4;
0030     sctx->count = 0;
0031
0032     return 0;
0033 }
0034
0035 static inline int sha1_base_do_update(struct shash_desc *desc,
0036                       const u8 *data,
0037                       unsigned int len,
0038                       sha1_block_fn *block_fn)
0039 {
0040     struct sha1_state *sctx = shash_desc_ctx(desc);
0041     unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
0042
0043     sctx->count += len;
0044
0045     if (unlikely((partial + len) >= SHA1_BLOCK_SIZE)) {
0046         int blocks;
0047
0048         if (partial) {
0049             int p = SHA1_BLOCK_SIZE - partial;
0050
0051             memcpy(sctx->buffer + partial, data, p);
0052             data += p;
0053             len -= p;
0054
0055             block_fn(sctx, sctx->buffer, 1);
0056         }
0057
0058         blocks = len / SHA1_BLOCK_SIZE;
0059         len %= SHA1_BLOCK_SIZE;
0060
0061         if (blocks) {
0062             block_fn(sctx, data, blocks);
0063             data += blocks * SHA1_BLOCK_SIZE;
0064         }
0065         partial = 0;
0066     }
0067     if (len)
0068         memcpy(sctx->buffer + partial, data, len);
0069
0070     return 0;
0071 }
0072
0073 static inline int sha1_base_do_finalize(struct shash_desc *desc,
0074                     sha1_block_fn *block_fn)
0075 {
0076     const int bit_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
0077     struct sha1_state *sctx = shash_desc_ctx(desc);
0078     __be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
0079     unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
0080
0081     sctx->buffer[partial++] = 0x80;
0082     if (partial > bit_offset) {
0083         memset(sctx->buffer + partial, 0x0, SHA1_BLOCK_SIZE - partial);
0084         partial = 0;
0085
0086         block_fn(sctx, sctx->buffer, 1);
0087     }
0088
0089     memset(sctx->buffer + partial, 0x0, bit_offset - partial);
0090     *bits = cpu_to_be64(sctx->count << 3);
0091     block_fn(sctx, sctx->buffer, 1);
0092
0093     return 0;
0094 }
0095
0096 static inline int sha1_base_finish(struct shash_desc *desc, u8 *out)
0097 {
0098     struct sha1_state *sctx = shash_desc_ctx(desc);
0099     __be32 *digest = (__be32 *)out;
0100     int i;
0101
0102     for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
0103         put_unaligned_be32(sctx->state[i], digest++);
0104
0105     memzero_explicit(sctx, sizeof(*sctx));
0106     return 0;
0107 }
0108
0109 #endif /* _CRYPTO_SHA1_BASE_H */