xref: /openbmc/linux/arch/powerpc/crypto/sha1.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Cryptographic API.
4  *
5  * powerpc implementation of the SHA1 Secure Hash Algorithm.
6  *
7  * Derived from cryptoapi implementation, adapted for in-place
8  * scatterlist interface.
9  *
10  * Derived from "crypto/sha1.c"
11  * Copyright (c) Alan Smithee.
12  * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
13  * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
14  */
15 #include <crypto/internal/hash.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/mm.h>
19 #include <linux/cryptohash.h>
20 #include <linux/types.h>
21 #include <crypto/sha.h>
22 #include <asm/byteorder.h>
23 
24 extern void powerpc_sha_transform(u32 *state, const u8 *src, u32 *temp);
25 
26 static int sha1_init(struct shash_desc *desc)
27 {
28 	struct sha1_state *sctx = shash_desc_ctx(desc);
29 
30 	*sctx = (struct sha1_state){
31 		.state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
32 	};
33 
34 	return 0;
35 }
36 
37 static int sha1_update(struct shash_desc *desc, const u8 *data,
38 			unsigned int len)
39 {
40 	struct sha1_state *sctx = shash_desc_ctx(desc);
41 	unsigned int partial, done;
42 	const u8 *src;
43 
44 	partial = sctx->count & 0x3f;
45 	sctx->count += len;
46 	done = 0;
47 	src = data;
48 
49 	if ((partial + len) > 63) {
50 		u32 temp[SHA_WORKSPACE_WORDS];
51 
52 		if (partial) {
53 			done = -partial;
54 			memcpy(sctx->buffer + partial, data, done + 64);
55 			src = sctx->buffer;
56 		}
57 
58 		do {
59 			powerpc_sha_transform(sctx->state, src, temp);
60 			done += 64;
61 			src = data + done;
62 		} while (done + 63 < len);
63 
64 		memzero_explicit(temp, sizeof(temp));
65 		partial = 0;
66 	}
67 	memcpy(sctx->buffer + partial, src, len - done);
68 
69 	return 0;
70 }
71 
72 
73 /* Add padding and return the message digest. */
74 static int sha1_final(struct shash_desc *desc, u8 *out)
75 {
76 	struct sha1_state *sctx = shash_desc_ctx(desc);
77 	__be32 *dst = (__be32 *)out;
78 	u32 i, index, padlen;
79 	__be64 bits;
80 	static const u8 padding[64] = { 0x80, };
81 
82 	bits = cpu_to_be64(sctx->count << 3);
83 
84 	/* Pad out to 56 mod 64 */
85 	index = sctx->count & 0x3f;
86 	padlen = (index < 56) ? (56 - index) : ((64+56) - index);
87 	sha1_update(desc, padding, padlen);
88 
89 	/* Append length */
90 	sha1_update(desc, (const u8 *)&bits, sizeof(bits));
91 
92 	/* Store state in digest */
93 	for (i = 0; i < 5; i++)
94 		dst[i] = cpu_to_be32(sctx->state[i]);
95 
96 	/* Wipe context */
97 	memset(sctx, 0, sizeof *sctx);
98 
99 	return 0;
100 }
101 
102 static int sha1_export(struct shash_desc *desc, void *out)
103 {
104 	struct sha1_state *sctx = shash_desc_ctx(desc);
105 
106 	memcpy(out, sctx, sizeof(*sctx));
107 	return 0;
108 }
109 
110 static int sha1_import(struct shash_desc *desc, const void *in)
111 {
112 	struct sha1_state *sctx = shash_desc_ctx(desc);
113 
114 	memcpy(sctx, in, sizeof(*sctx));
115 	return 0;
116 }
117 
118 static struct shash_alg alg = {
119 	.digestsize	=	SHA1_DIGEST_SIZE,
120 	.init		=	sha1_init,
121 	.update		=	sha1_update,
122 	.final		=	sha1_final,
123 	.export		=	sha1_export,
124 	.import		=	sha1_import,
125 	.descsize	=	sizeof(struct sha1_state),
126 	.statesize	=	sizeof(struct sha1_state),
127 	.base		=	{
128 		.cra_name	=	"sha1",
129 		.cra_driver_name=	"sha1-powerpc",
130 		.cra_blocksize	=	SHA1_BLOCK_SIZE,
131 		.cra_module	=	THIS_MODULE,
132 	}
133 };
134 
135 static int __init sha1_powerpc_mod_init(void)
136 {
137 	return crypto_register_shash(&alg);
138 }
139 
140 static void __exit sha1_powerpc_mod_fini(void)
141 {
142 	crypto_unregister_shash(&alg);
143 }
144 
145 module_init(sha1_powerpc_mod_init);
146 module_exit(sha1_powerpc_mod_fini);
147 
148 MODULE_LICENSE("GPL");
149 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
150 
151 MODULE_ALIAS_CRYPTO("sha1");
152 MODULE_ALIAS_CRYPTO("sha1-powerpc");
153