1/*
  2 * sha1_base.h - core logic for SHA-1 implementations
  3 *
  4 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 */
 10
 11#include <crypto/internal/hash.h>
 12#include <crypto/sha.h>
 13#include <linux/crypto.h>
 14#include <linux/module.h>
 15
 16#include <asm/unaligned.h>
 17
 18typedef void (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks);
 19
 20static inline int sha1_base_init(struct shash_desc *desc)
 21{
 22	struct sha1_state *sctx = shash_desc_ctx(desc);
 23
 24	sctx->state[0] = SHA1_H0;
 25	sctx->state[1] = SHA1_H1;
 26	sctx->state[2] = SHA1_H2;
 27	sctx->state[3] = SHA1_H3;
 28	sctx->state[4] = SHA1_H4;
 29	sctx->count = 0;
 30
 31	return 0;
 32}
 33
 34static inline int sha1_base_do_update(struct shash_desc *desc,
 35				      const u8 *data,
 36				      unsigned int len,
 37				      sha1_block_fn *block_fn)
 38{
 39	struct sha1_state *sctx = shash_desc_ctx(desc);
 40	unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
 41
 42	sctx->count += len;
 43
 44	if (unlikely((partial + len) >= SHA1_BLOCK_SIZE)) {
 45		int blocks;
 46
 47		if (partial) {
 48			int p = SHA1_BLOCK_SIZE - partial;
 49
 50			memcpy(sctx->buffer + partial, data, p);
 51			data += p;
 52			len -= p;
 53
 54			block_fn(sctx, sctx->buffer, 1);
 55		}
 56
 57		blocks = len / SHA1_BLOCK_SIZE;
 58		len %= SHA1_BLOCK_SIZE;
 59
 60		if (blocks) {
 61			block_fn(sctx, data, blocks);
 62			data += blocks * SHA1_BLOCK_SIZE;
 63		}
 64		partial = 0;
 65	}
 66	if (len)
 67		memcpy(sctx->buffer + partial, data, len);
 68
 69	return 0;
 70}
 71
 72static inline int sha1_base_do_finalize(struct shash_desc *desc,
 73					sha1_block_fn *block_fn)
 74{
 75	const int bit_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
 76	struct sha1_state *sctx = shash_desc_ctx(desc);
 77	__be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
 78	unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
 79
 80	sctx->buffer[partial++] = 0x80;
 81	if (partial > bit_offset) {
 82		memset(sctx->buffer + partial, 0x0, SHA1_BLOCK_SIZE - partial);
 83		partial = 0;
 84
 85		block_fn(sctx, sctx->buffer, 1);
 86	}
 87
 88	memset(sctx->buffer + partial, 0x0, bit_offset - partial);
 89	*bits = cpu_to_be64(sctx->count << 3);
 90	block_fn(sctx, sctx->buffer, 1);
 91
 92	return 0;
 93}
 94
 95static inline int sha1_base_finish(struct shash_desc *desc, u8 *out)
 96{
 97	struct sha1_state *sctx = shash_desc_ctx(desc);
 98	__be32 *digest = (__be32 *)out;
 99	int i;
100
101	for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
102		put_unaligned_be32(sctx->state[i], digest++);
103
104	*sctx = (struct sha1_state){};
105	return 0;
106}