1/*
2 * Cryptographic API.
3 *
4 * powerpc implementation of the SHA1 Secure Hash Algorithm.
5 *
6 * Derived from cryptoapi implementation, adapted for in-place
7 * scatterlist interface.
8 *
9 * Derived from "crypto/sha1.c"
10 * Copyright (c) Alan Smithee.
11 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
12 * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
13 *
14 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the Free
16 * Software Foundation; either version 2 of the License, or (at your option)
17 * any later version.
18 *
19 */
20#include <crypto/internal/hash.h>
21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/mm.h>
24#include <linux/cryptohash.h>
25#include <linux/types.h>
26#include <crypto/sha.h>
27#include <asm/byteorder.h>
28
29extern void powerpc_sha_transform(u32 *state, const u8 *src, u32 *temp);
30
31static int sha1_init(struct shash_desc *desc)
32{
33	struct sha1_state *sctx = shash_desc_ctx(desc);
34
35	*sctx = (struct sha1_state){
36		.state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
37	};
38
39	return 0;
40}
41
42static int sha1_update(struct shash_desc *desc, const u8 *data,
43			unsigned int len)
44{
45	struct sha1_state *sctx = shash_desc_ctx(desc);
46	unsigned int partial, done;
47	const u8 *src;
48
49	partial = sctx->count & 0x3f;
50	sctx->count += len;
51	done = 0;
52	src = data;
53
54	if ((partial + len) > 63) {
55		u32 temp[SHA_WORKSPACE_WORDS];
56
57		if (partial) {
58			done = -partial;
59			memcpy(sctx->buffer + partial, data, done + 64);
60			src = sctx->buffer;
61		}
62
63		do {
64			powerpc_sha_transform(sctx->state, src, temp);
65			done += 64;
66			src = data + done;
67		} while (done + 63 < len);
68
69		memzero_explicit(temp, sizeof(temp));
70		partial = 0;
71	}
72	memcpy(sctx->buffer + partial, src, len - done);
73
74	return 0;
75}
76
77
78/* Add padding and return the message digest. */
79static int sha1_final(struct shash_desc *desc, u8 *out)
80{
81	struct sha1_state *sctx = shash_desc_ctx(desc);
82	__be32 *dst = (__be32 *)out;
83	u32 i, index, padlen;
84	__be64 bits;
85	static const u8 padding[64] = { 0x80, };
86
87	bits = cpu_to_be64(sctx->count << 3);
88
89	/* Pad out to 56 mod 64 */
90	index = sctx->count & 0x3f;
91	padlen = (index < 56) ? (56 - index) : ((64+56) - index);
92	sha1_update(desc, padding, padlen);
93
94	/* Append length */
95	sha1_update(desc, (const u8 *)&bits, sizeof(bits));
96
97	/* Store state in digest */
98	for (i = 0; i < 5; i++)
99		dst[i] = cpu_to_be32(sctx->state[i]);
100
101	/* Wipe context */
102	memset(sctx, 0, sizeof *sctx);
103
104	return 0;
105}
106
107static int sha1_export(struct shash_desc *desc, void *out)
108{
109	struct sha1_state *sctx = shash_desc_ctx(desc);
110
111	memcpy(out, sctx, sizeof(*sctx));
112	return 0;
113}
114
115static int sha1_import(struct shash_desc *desc, const void *in)
116{
117	struct sha1_state *sctx = shash_desc_ctx(desc);
118
119	memcpy(sctx, in, sizeof(*sctx));
120	return 0;
121}
122
123static struct shash_alg alg = {
124	.digestsize	=	SHA1_DIGEST_SIZE,
125	.init		=	sha1_init,
126	.update		=	sha1_update,
127	.final		=	sha1_final,
128	.export		=	sha1_export,
129	.import		=	sha1_import,
130	.descsize	=	sizeof(struct sha1_state),
131	.statesize	=	sizeof(struct sha1_state),
132	.base		=	{
133		.cra_name	=	"sha1",
134		.cra_driver_name=	"sha1-powerpc",
135		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
136		.cra_blocksize	=	SHA1_BLOCK_SIZE,
137		.cra_module	=	THIS_MODULE,
138	}
139};
140
141static int __init sha1_powerpc_mod_init(void)
142{
143	return crypto_register_shash(&alg);
144}
145
146static void __exit sha1_powerpc_mod_fini(void)
147{
148	crypto_unregister_shash(&alg);
149}
150
151module_init(sha1_powerpc_mod_init);
152module_exit(sha1_powerpc_mod_fini);
153
154MODULE_LICENSE("GPL");
155MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
156
157MODULE_ALIAS_CRYPTO("sha1");
158MODULE_ALIAS_CRYPTO("sha1-powerpc");
159