1/*
2 * Cryptographic API.
3 *
4 * s390 implementation of the SHA1 Secure Hash Algorithm.
5 *
6 * Derived from cryptoapi implementation, adapted for in-place
7 * scatterlist interface.  Originally based on the public domain
8 * implementation written by Steve Reid.
9 *
10 * s390 Version:
11 *   Copyright IBM Corp. 2003,2007
12 *   Author(s): Thomas Spatzier
13 *		Jan Glauber (jan.glauber@de.ibm.com)
14 *
15 * Derived from "crypto/sha1.c"
16 *   Copyright (c) Alan Smithee.
17 *   Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
18 *   Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
19 *
20 * This program is free software; you can redistribute it and/or modify it
21 * under the terms of the GNU General Public License as published by the Free
22 * Software Foundation; either version 2 of the License, or (at your option)
23 * any later version.
24 *
25 */
26#include <linux/init.h>
27#include <linux/module.h>
28#include <linux/crypto.h>
29
30#include "crypt_s390.h"
31
32#define SHA1_DIGEST_SIZE	20
33#define SHA1_BLOCK_SIZE		64
34
35struct s390_sha1_ctx {
36	u64 count;		/* message length */
37	u32 state[5];
38	u8 buf[2 * SHA1_BLOCK_SIZE];
39};
40
41static void sha1_init(struct crypto_tfm *tfm)
42{
43	struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
44
45	sctx->state[0] = 0x67452301;
46	sctx->state[1] = 0xEFCDAB89;
47	sctx->state[2] = 0x98BADCFE;
48	sctx->state[3] = 0x10325476;
49	sctx->state[4] = 0xC3D2E1F0;
50	sctx->count = 0;
51}
52
53static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
54			unsigned int len)
55{
56	struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
57	unsigned int index;
58	int ret;
59
60	/* how much is already in the buffer? */
61	index = sctx->count & 0x3f;
62
63	sctx->count += len;
64
65	if (index + len < SHA1_BLOCK_SIZE)
66		goto store;
67
68	/* process one stored block */
69	if (index) {
70		memcpy(sctx->buf + index, data, SHA1_BLOCK_SIZE - index);
71		ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf,
72				      SHA1_BLOCK_SIZE);
73		BUG_ON(ret != SHA1_BLOCK_SIZE);
74		data += SHA1_BLOCK_SIZE - index;
75		len -= SHA1_BLOCK_SIZE - index;
76	}
77
78	/* process as many blocks as possible */
79	if (len >= SHA1_BLOCK_SIZE) {
80		ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, data,
81				      len & ~(SHA1_BLOCK_SIZE - 1));
82		BUG_ON(ret != (len & ~(SHA1_BLOCK_SIZE - 1)));
83		data += ret;
84		len -= ret;
85	}
86
87store:
88	/* anything left? */
89	if (len)
90		memcpy(sctx->buf + index , data, len);
91}
92
93/* Add padding and return the message digest. */
94static void sha1_final(struct crypto_tfm *tfm, u8 *out)
95{
96	struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
97	u64 bits;
98	unsigned int index, end;
99	int ret;
100
101	/* must perform manual padding */
102	index = sctx->count & 0x3f;
103	end =  (index < 56) ? SHA1_BLOCK_SIZE : (2 * SHA1_BLOCK_SIZE);
104
105	/* start pad with 1 */
106	sctx->buf[index] = 0x80;
107
108	/* pad with zeros */
109	index++;
110	memset(sctx->buf + index, 0x00, end - index - 8);
111
112	/* append message length */
113	bits = sctx->count * 8;
114	memcpy(sctx->buf + end - 8, &bits, sizeof(bits));
115
116	ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf, end);
117	BUG_ON(ret != end);
118
119	/* copy digest to out */
120	memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
121
122	/* wipe context */
123	memset(sctx, 0, sizeof *sctx);
124}
125
126static struct crypto_alg alg = {
127	.cra_name	=	"sha1",
128	.cra_driver_name=	"sha1-s390",
129	.cra_priority	=	CRYPT_S390_PRIORITY,
130	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
131	.cra_blocksize	=	SHA1_BLOCK_SIZE,
132	.cra_ctxsize	=	sizeof(struct s390_sha1_ctx),
133	.cra_module	=	THIS_MODULE,
134	.cra_list	=	LIST_HEAD_INIT(alg.cra_list),
135	.cra_u		=	{ .digest = {
136	.dia_digestsize	=	SHA1_DIGEST_SIZE,
137	.dia_init	=	sha1_init,
138	.dia_update	=	sha1_update,
139	.dia_final	=	sha1_final } }
140};
141
142static int __init init(void)
143{
144	if (!crypt_s390_func_available(KIMD_SHA_1))
145		return -EOPNOTSUPP;
146
147	return crypto_register_alg(&alg);
148}
149
150static void __exit fini(void)
151{
152	crypto_unregister_alg(&alg);
153}
154
155module_init(init);
156module_exit(fini);
157
158MODULE_ALIAS("sha1");
159
160MODULE_LICENSE("GPL");
161MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
162