xref: /linux/include/crypto/sha512_base.h (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
1 /*
2  * sha512_base.h - core logic for SHA-512 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 (sha512_block_fn)(struct sha512_state *sst, u8 const *src,
19 			       int blocks);
20 
21 static inline int sha384_base_init(struct shash_desc *desc)
22 {
23 	struct sha512_state *sctx = shash_desc_ctx(desc);
24 
25 	sctx->state[0] = SHA384_H0;
26 	sctx->state[1] = SHA384_H1;
27 	sctx->state[2] = SHA384_H2;
28 	sctx->state[3] = SHA384_H3;
29 	sctx->state[4] = SHA384_H4;
30 	sctx->state[5] = SHA384_H5;
31 	sctx->state[6] = SHA384_H6;
32 	sctx->state[7] = SHA384_H7;
33 	sctx->count[0] = sctx->count[1] = 0;
34 
35 	return 0;
36 }
37 
38 static inline int sha512_base_init(struct shash_desc *desc)
39 {
40 	struct sha512_state *sctx = shash_desc_ctx(desc);
41 
42 	sctx->state[0] = SHA512_H0;
43 	sctx->state[1] = SHA512_H1;
44 	sctx->state[2] = SHA512_H2;
45 	sctx->state[3] = SHA512_H3;
46 	sctx->state[4] = SHA512_H4;
47 	sctx->state[5] = SHA512_H5;
48 	sctx->state[6] = SHA512_H6;
49 	sctx->state[7] = SHA512_H7;
50 	sctx->count[0] = sctx->count[1] = 0;
51 
52 	return 0;
53 }
54 
55 static inline int sha512_base_do_update(struct shash_desc *desc,
56 					const u8 *data,
57 					unsigned int len,
58 					sha512_block_fn *block_fn)
59 {
60 	struct sha512_state *sctx = shash_desc_ctx(desc);
61 	unsigned int partial = sctx->count[0] % SHA512_BLOCK_SIZE;
62 
63 	sctx->count[0] += len;
64 	if (sctx->count[0] < len)
65 		sctx->count[1]++;
66 
67 	if (unlikely((partial + len) >= SHA512_BLOCK_SIZE)) {
68 		int blocks;
69 
70 		if (partial) {
71 			int p = SHA512_BLOCK_SIZE - partial;
72 
73 			memcpy(sctx->buf + partial, data, p);
74 			data += p;
75 			len -= p;
76 
77 			block_fn(sctx, sctx->buf, 1);
78 		}
79 
80 		blocks = len / SHA512_BLOCK_SIZE;
81 		len %= SHA512_BLOCK_SIZE;
82 
83 		if (blocks) {
84 			block_fn(sctx, data, blocks);
85 			data += blocks * SHA512_BLOCK_SIZE;
86 		}
87 		partial = 0;
88 	}
89 	if (len)
90 		memcpy(sctx->buf + partial, data, len);
91 
92 	return 0;
93 }
94 
95 static inline int sha512_base_do_finalize(struct shash_desc *desc,
96 					  sha512_block_fn *block_fn)
97 {
98 	const int bit_offset = SHA512_BLOCK_SIZE - sizeof(__be64[2]);
99 	struct sha512_state *sctx = shash_desc_ctx(desc);
100 	__be64 *bits = (__be64 *)(sctx->buf + bit_offset);
101 	unsigned int partial = sctx->count[0] % SHA512_BLOCK_SIZE;
102 
103 	sctx->buf[partial++] = 0x80;
104 	if (partial > bit_offset) {
105 		memset(sctx->buf + partial, 0x0, SHA512_BLOCK_SIZE - partial);
106 		partial = 0;
107 
108 		block_fn(sctx, sctx->buf, 1);
109 	}
110 
111 	memset(sctx->buf + partial, 0x0, bit_offset - partial);
112 	bits[0] = cpu_to_be64(sctx->count[1] << 3 | sctx->count[0] >> 61);
113 	bits[1] = cpu_to_be64(sctx->count[0] << 3);
114 	block_fn(sctx, sctx->buf, 1);
115 
116 	return 0;
117 }
118 
119 static inline int sha512_base_finish(struct shash_desc *desc, u8 *out)
120 {
121 	unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
122 	struct sha512_state *sctx = shash_desc_ctx(desc);
123 	__be64 *digest = (__be64 *)out;
124 	int i;
125 
126 	for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be64))
127 		put_unaligned_be64(sctx->state[i], digest++);
128 
129 	*sctx = (struct sha512_state){};
130 	return 0;
131 }
132