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 
18 typedef void (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks);
19 
sha1_base_init(struct shash_desc * desc)20 static 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 
sha1_base_do_update(struct shash_desc * desc,const u8 * data,unsigned int len,sha1_block_fn * block_fn)34 static 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 
sha1_base_do_finalize(struct shash_desc * desc,sha1_block_fn * block_fn)72 static 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 
sha1_base_finish(struct shash_desc * desc,u8 * out)95 static 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