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}
107