1  /* SPDX-License-Identifier: GPL-2.0-only */
2  /*
3   * sha256_base.h - core logic for SHA-256 implementations
4   *
5   * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
6   */
7  
8  #ifndef _CRYPTO_SHA256_BASE_H
9  #define _CRYPTO_SHA256_BASE_H
10  
11  #include <asm/byteorder.h>
12  #include <linux/unaligned.h>
13  #include <crypto/internal/hash.h>
14  #include <crypto/sha2.h>
15  #include <linux/string.h>
16  #include <linux/types.h>
17  
18  typedef void (sha256_block_fn)(struct sha256_state *sst, u8 const *src,
19  			       int blocks);
20  
sha224_base_init(struct shash_desc * desc)21  static inline int sha224_base_init(struct shash_desc *desc)
22  {
23  	struct sha256_state *sctx = shash_desc_ctx(desc);
24  
25  	sha224_init(sctx);
26  	return 0;
27  }
28  
sha256_base_init(struct shash_desc * desc)29  static inline int sha256_base_init(struct shash_desc *desc)
30  {
31  	struct sha256_state *sctx = shash_desc_ctx(desc);
32  
33  	sha256_init(sctx);
34  	return 0;
35  }
36  
lib_sha256_base_do_update(struct sha256_state * sctx,const u8 * data,unsigned int len,sha256_block_fn * block_fn)37  static inline int lib_sha256_base_do_update(struct sha256_state *sctx,
38  					    const u8 *data,
39  					    unsigned int len,
40  					    sha256_block_fn *block_fn)
41  {
42  	unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
43  
44  	sctx->count += len;
45  
46  	if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) {
47  		int blocks;
48  
49  		if (partial) {
50  			int p = SHA256_BLOCK_SIZE - partial;
51  
52  			memcpy(sctx->buf + partial, data, p);
53  			data += p;
54  			len -= p;
55  
56  			block_fn(sctx, sctx->buf, 1);
57  		}
58  
59  		blocks = len / SHA256_BLOCK_SIZE;
60  		len %= SHA256_BLOCK_SIZE;
61  
62  		if (blocks) {
63  			block_fn(sctx, data, blocks);
64  			data += blocks * SHA256_BLOCK_SIZE;
65  		}
66  		partial = 0;
67  	}
68  	if (len)
69  		memcpy(sctx->buf + partial, data, len);
70  
71  	return 0;
72  }
73  
sha256_base_do_update(struct shash_desc * desc,const u8 * data,unsigned int len,sha256_block_fn * block_fn)74  static inline int sha256_base_do_update(struct shash_desc *desc,
75  					const u8 *data,
76  					unsigned int len,
77  					sha256_block_fn *block_fn)
78  {
79  	struct sha256_state *sctx = shash_desc_ctx(desc);
80  
81  	return lib_sha256_base_do_update(sctx, data, len, block_fn);
82  }
83  
lib_sha256_base_do_finalize(struct sha256_state * sctx,sha256_block_fn * block_fn)84  static inline int lib_sha256_base_do_finalize(struct sha256_state *sctx,
85  					      sha256_block_fn *block_fn)
86  {
87  	const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64);
88  	__be64 *bits = (__be64 *)(sctx->buf + bit_offset);
89  	unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
90  
91  	sctx->buf[partial++] = 0x80;
92  	if (partial > bit_offset) {
93  		memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial);
94  		partial = 0;
95  
96  		block_fn(sctx, sctx->buf, 1);
97  	}
98  
99  	memset(sctx->buf + partial, 0x0, bit_offset - partial);
100  	*bits = cpu_to_be64(sctx->count << 3);
101  	block_fn(sctx, sctx->buf, 1);
102  
103  	return 0;
104  }
105  
sha256_base_do_finalize(struct shash_desc * desc,sha256_block_fn * block_fn)106  static inline int sha256_base_do_finalize(struct shash_desc *desc,
107  					  sha256_block_fn *block_fn)
108  {
109  	struct sha256_state *sctx = shash_desc_ctx(desc);
110  
111  	return lib_sha256_base_do_finalize(sctx, block_fn);
112  }
113  
lib_sha256_base_finish(struct sha256_state * sctx,u8 * out,unsigned int digest_size)114  static inline int lib_sha256_base_finish(struct sha256_state *sctx, u8 *out,
115  					 unsigned int digest_size)
116  {
117  	__be32 *digest = (__be32 *)out;
118  	int i;
119  
120  	for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
121  		put_unaligned_be32(sctx->state[i], digest++);
122  
123  	memzero_explicit(sctx, sizeof(*sctx));
124  	return 0;
125  }
126  
sha256_base_finish(struct shash_desc * desc,u8 * out)127  static inline int sha256_base_finish(struct shash_desc *desc, u8 *out)
128  {
129  	unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
130  	struct sha256_state *sctx = shash_desc_ctx(desc);
131  
132  	return lib_sha256_base_finish(sctx, out, digest_size);
133  }
134  
135  #endif /* _CRYPTO_SHA256_BASE_H */
136