xref: /openbmc/linux/arch/powerpc/crypto/sha1.c (revision b737eecd)
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/types.h>
20 #include <crypto/sha1.h>
21 #include <asm/byteorder.h>
22 
23 void powerpc_sha_transform(u32 *state, const u8 *src);
24 
25 static int powerpc_sha1_init(struct shash_desc *desc)
26 {
27 	struct sha1_state *sctx = shash_desc_ctx(desc);
28 
29 	*sctx = (struct sha1_state){
30 		.state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
31 	};
32 
33 	return 0;
34 }
35 
36 static int powerpc_sha1_update(struct shash_desc *desc, const u8 *data,
37 			       unsigned int len)
38 {
39 	struct sha1_state *sctx = shash_desc_ctx(desc);
40 	unsigned int partial, done;
41 	const u8 *src;
42 
43 	partial = sctx->count & 0x3f;
44 	sctx->count += len;
45 	done = 0;
46 	src = data;
47 
48 	if ((partial + len) > 63) {
49 
50 		if (partial) {
51 			done = -partial;
52 			memcpy(sctx->buffer + partial, data, done + 64);
53 			src = sctx->buffer;
54 		}
55 
56 		do {
57 			powerpc_sha_transform(sctx->state, src);
58 			done += 64;
59 			src = data + done;
60 		} while (done + 63 < len);
61 
62 		partial = 0;
63 	}
64 	memcpy(sctx->buffer + partial, src, len - done);
65 
66 	return 0;
67 }
68 
69 
70 /* Add padding and return the message digest. */
71 static int powerpc_sha1_final(struct shash_desc *desc, u8 *out)
72 {
73 	struct sha1_state *sctx = shash_desc_ctx(desc);
74 	__be32 *dst = (__be32 *)out;
75 	u32 i, index, padlen;
76 	__be64 bits;
77 	static const u8 padding[64] = { 0x80, };
78 
79 	bits = cpu_to_be64(sctx->count << 3);
80 
81 	/* Pad out to 56 mod 64 */
82 	index = sctx->count & 0x3f;
83 	padlen = (index < 56) ? (56 - index) : ((64+56) - index);
84 	powerpc_sha1_update(desc, padding, padlen);
85 
86 	/* Append length */
87 	powerpc_sha1_update(desc, (const u8 *)&bits, sizeof(bits));
88 
89 	/* Store state in digest */
90 	for (i = 0; i < 5; i++)
91 		dst[i] = cpu_to_be32(sctx->state[i]);
92 
93 	/* Wipe context */
94 	memset(sctx, 0, sizeof *sctx);
95 
96 	return 0;
97 }
98 
99 static int powerpc_sha1_export(struct shash_desc *desc, void *out)
100 {
101 	struct sha1_state *sctx = shash_desc_ctx(desc);
102 
103 	memcpy(out, sctx, sizeof(*sctx));
104 	return 0;
105 }
106 
107 static int powerpc_sha1_import(struct shash_desc *desc, const void *in)
108 {
109 	struct sha1_state *sctx = shash_desc_ctx(desc);
110 
111 	memcpy(sctx, in, sizeof(*sctx));
112 	return 0;
113 }
114 
115 static struct shash_alg alg = {
116 	.digestsize	=	SHA1_DIGEST_SIZE,
117 	.init		=	powerpc_sha1_init,
118 	.update		=	powerpc_sha1_update,
119 	.final		=	powerpc_sha1_final,
120 	.export		=	powerpc_sha1_export,
121 	.import		=	powerpc_sha1_import,
122 	.descsize	=	sizeof(struct sha1_state),
123 	.statesize	=	sizeof(struct sha1_state),
124 	.base		=	{
125 		.cra_name	=	"sha1",
126 		.cra_driver_name=	"sha1-powerpc",
127 		.cra_blocksize	=	SHA1_BLOCK_SIZE,
128 		.cra_module	=	THIS_MODULE,
129 	}
130 };
131 
132 static int __init sha1_powerpc_mod_init(void)
133 {
134 	return crypto_register_shash(&alg);
135 }
136 
137 static void __exit sha1_powerpc_mod_fini(void)
138 {
139 	crypto_unregister_shash(&alg);
140 }
141 
142 module_init(sha1_powerpc_mod_init);
143 module_exit(sha1_powerpc_mod_fini);
144 
145 MODULE_LICENSE("GPL");
146 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
147 
148 MODULE_ALIAS_CRYPTO("sha1");
149 MODULE_ALIAS_CRYPTO("sha1-powerpc");
150