summaryrefslogtreecommitdiff
path: root/arch/s390/crypto/sha1_s390.c
blob: 49ca8690ee39b7d53e116274b74bd883698a2e01 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/*
 * Cryptographic API.
 *
 * s390 implementation of the SHA1 Secure Hash Algorithm.
 *
 * Derived from cryptoapi implementation, adapted for in-place
 * scatterlist interface.  Originally based on the public domain
 * implementation written by Steve Reid.
 *
 * s390 Version:
 *   Copyright (C) 2003 IBM Deutschland GmbH, IBM Corporation
 *   Author(s): Thomas Spatzier (tspat@de.ibm.com)
 *
 * Derived from "crypto/sha1.c"
 *   Copyright (c) Alan Smithee.
 *   Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
 *   Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/crypto.h>
#include <asm/scatterlist.h>
#include <asm/byteorder.h>
#include "crypt_s390.h"

#define SHA1_DIGEST_SIZE	20
#define SHA1_BLOCK_SIZE		64

struct crypt_s390_sha1_ctx {
	u64 count;
	u32 state[5];
	u32 buf_len;
	u8 buffer[2 * SHA1_BLOCK_SIZE];
};

static void sha1_init(struct crypto_tfm *tfm)
{
	struct crypt_s390_sha1_ctx *ctx = crypto_tfm_ctx(tfm);
	static const u32 initstate[5] = {
		0x67452301,
		0xEFCDAB89,
		0x98BADCFE,
		0x10325476,
		0xC3D2E1F0
	};

	ctx->count = 0;
	memcpy(ctx->state, &initstate, sizeof(initstate));
	ctx->buf_len = 0;
}

static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
			unsigned int len)
{
	struct crypt_s390_sha1_ctx *sctx;
	long imd_len;

	sctx = crypto_tfm_ctx(tfm);
	sctx->count += len * 8; //message bit length

	//anything in buffer yet? -> must be completed
	if (sctx->buf_len && (sctx->buf_len + len) >= SHA1_BLOCK_SIZE) {
		//complete full block and hash
		memcpy(sctx->buffer + sctx->buf_len, data,
				SHA1_BLOCK_SIZE - sctx->buf_len);
		crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer,
				SHA1_BLOCK_SIZE);
		data += SHA1_BLOCK_SIZE - sctx->buf_len;
		len -= SHA1_BLOCK_SIZE - sctx->buf_len;
		sctx->buf_len = 0;
	}

	//rest of data contains full blocks?
	imd_len = len & ~0x3ful;
	if (imd_len){
		crypt_s390_kimd(KIMD_SHA_1, sctx->state, data, imd_len);
		data += imd_len;
		len -= imd_len;
	}
	//anything left? store in buffer
	if (len){
		memcpy(sctx->buffer + sctx->buf_len , data, len);
		sctx->buf_len += len;
	}
}


static void
pad_message(struct crypt_s390_sha1_ctx* sctx)
{
	int index;

	index = sctx->buf_len;
	sctx->buf_len = (sctx->buf_len < 56)?
		SHA1_BLOCK_SIZE:2 * SHA1_BLOCK_SIZE;
	//start pad with 1
	sctx->buffer[index] = 0x80;
	//pad with zeros
	index++;
	memset(sctx->buffer + index, 0x00, sctx->buf_len - index);
	//append length
	memcpy(sctx->buffer + sctx->buf_len - 8, &sctx->count,
			sizeof sctx->count);
}

/* Add padding and return the message digest. */
static void sha1_final(struct crypto_tfm *tfm, u8 *out)
{
	struct crypt_s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);

	//must perform manual padding
	pad_message(sctx);
	crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer, sctx->buf_len);
	//copy digest to out
	memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
	/* Wipe context */
	memset(sctx, 0, sizeof *sctx);
}

static struct crypto_alg alg = {
	.cra_name	=	"sha1",
	.cra_driver_name =	"sha1-s390",
	.cra_priority	=	CRYPT_S390_PRIORITY,
	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
	.cra_blocksize	=	SHA1_BLOCK_SIZE,
	.cra_ctxsize	=	sizeof(struct crypt_s390_sha1_ctx),
	.cra_module	=	THIS_MODULE,
	.cra_list       =       LIST_HEAD_INIT(alg.cra_list),
	.cra_u		=	{ .digest = {
	.dia_digestsize	=	SHA1_DIGEST_SIZE,
	.dia_init   	= 	sha1_init,
	.dia_update 	=	sha1_update,
	.dia_final  	=	sha1_final } }
};

static int
init(void)
{
	int ret = -ENOSYS;

	if (crypt_s390_func_available(KIMD_SHA_1)){
		ret = crypto_register_alg(&alg);
		if (ret == 0){
			printk(KERN_INFO "crypt_s390: sha1_s390 loaded.\n");
		}
	}
	return ret;
}

static void __exit
fini(void)
{
	crypto_unregister_alg(&alg);
}

module_init(init);
module_exit(fini);

MODULE_ALIAS("sha1");

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");