1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * sha1_base.h - core logic for SHA-1 implementations
4  *
5  * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
6  */
7 
8 #ifndef _CRYPTO_SHA1_BASE_H
9 #define _CRYPTO_SHA1_BASE_H
10 
11 #include <crypto/internal/hash.h>
12 #include <crypto/sha1.h>
13 #include <linux/math.h>
14 #include <linux/string.h>
15 #include <linux/types.h>
16 #include <linux/unaligned.h>
17 
18 typedef void (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks);
19 
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 
34 static inline int sha1_base_do_update_blocks(struct shash_desc *desc,
35 					     const u8 *data,
36 					     unsigned int len,
37 					     sha1_block_fn *block_fn)
38 {
39 	unsigned int remain = len - round_down(len, SHA1_BLOCK_SIZE);
40 	struct sha1_state *sctx = shash_desc_ctx(desc);
41 
42 	sctx->count += len - remain;
43 	block_fn(sctx, data, len / SHA1_BLOCK_SIZE);
44 	return remain;
45 }
46 
47 static inline int sha1_base_do_finup(struct shash_desc *desc,
48 				     const u8 *src, unsigned int len,
49 				     sha1_block_fn *block_fn)
50 {
51 	unsigned int bit_offset = SHA1_BLOCK_SIZE / 8 - 1;
52 	struct sha1_state *sctx = shash_desc_ctx(desc);
53 	union {
54 		__be64 b64[SHA1_BLOCK_SIZE / 4];
55 		u8 u8[SHA1_BLOCK_SIZE * 2];
56 	} block = {};
57 
58 	if (len >= bit_offset * 8)
59 		bit_offset += SHA1_BLOCK_SIZE / 8;
60 	memcpy(&block, src, len);
61 	block.u8[len] = 0x80;
62 	sctx->count += len;
63 	block.b64[bit_offset] = cpu_to_be64(sctx->count << 3);
64 	block_fn(sctx, block.u8, (bit_offset + 1) * 8 / SHA1_BLOCK_SIZE);
65 	memzero_explicit(&block, sizeof(block));
66 
67 	return 0;
68 }
69 
70 static inline int sha1_base_finish(struct shash_desc *desc, u8 *out)
71 {
72 	struct sha1_state *sctx = shash_desc_ctx(desc);
73 	__be32 *digest = (__be32 *)out;
74 	int i;
75 
76 	for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
77 		put_unaligned_be32(sctx->state[i], digest++);
78 
79 	return 0;
80 }
81 
82 #endif /* _CRYPTO_SHA1_BASE_H */
83