xref: /linux/arch/s390/crypto/sha1_s390.c (revision f24e9f586b377749dff37554696cf3a105540c94)
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 (C) 2003 IBM Deutschland GmbH, IBM Corporation
12  *   Author(s): Thomas Spatzier (tspat@de.ibm.com)
13  *
14  * Derived from "crypto/sha1.c"
15  *   Copyright (c) Alan Smithee.
16  *   Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
17  *   Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
18  *
19  * This program is free software; you can redistribute it and/or modify it
20  * under the terms of the GNU General Public License as published by the Free
21  * Software Foundation; either version 2 of the License, or (at your option)
22  * any later version.
23  *
24  */
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/mm.h>
28 #include <linux/crypto.h>
29 #include <asm/scatterlist.h>
30 #include <asm/byteorder.h>
31 #include "crypt_s390.h"
32 
33 #define SHA1_DIGEST_SIZE	20
34 #define SHA1_BLOCK_SIZE		64
35 
36 struct crypt_s390_sha1_ctx {
37 	u64 count;
38 	u32 state[5];
39 	u32 buf_len;
40 	u8 buffer[2 * SHA1_BLOCK_SIZE];
41 };
42 
43 static void sha1_init(struct crypto_tfm *tfm)
44 {
45 	struct crypt_s390_sha1_ctx *ctx = crypto_tfm_ctx(tfm);
46 	static const u32 initstate[5] = {
47 		0x67452301,
48 		0xEFCDAB89,
49 		0x98BADCFE,
50 		0x10325476,
51 		0xC3D2E1F0
52 	};
53 
54 	ctx->count = 0;
55 	memcpy(ctx->state, &initstate, sizeof(initstate));
56 	ctx->buf_len = 0;
57 }
58 
59 static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
60 			unsigned int len)
61 {
62 	struct crypt_s390_sha1_ctx *sctx;
63 	long imd_len;
64 
65 	sctx = crypto_tfm_ctx(tfm);
66 	sctx->count += len * 8; //message bit length
67 
68 	//anything in buffer yet? -> must be completed
69 	if (sctx->buf_len && (sctx->buf_len + len) >= SHA1_BLOCK_SIZE) {
70 		//complete full block and hash
71 		memcpy(sctx->buffer + sctx->buf_len, data,
72 				SHA1_BLOCK_SIZE - sctx->buf_len);
73 		crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer,
74 				SHA1_BLOCK_SIZE);
75 		data += SHA1_BLOCK_SIZE - sctx->buf_len;
76 		len -= SHA1_BLOCK_SIZE - sctx->buf_len;
77 		sctx->buf_len = 0;
78 	}
79 
80 	//rest of data contains full blocks?
81 	imd_len = len & ~0x3ful;
82 	if (imd_len){
83 		crypt_s390_kimd(KIMD_SHA_1, sctx->state, data, imd_len);
84 		data += imd_len;
85 		len -= imd_len;
86 	}
87 	//anything left? store in buffer
88 	if (len){
89 		memcpy(sctx->buffer + sctx->buf_len , data, len);
90 		sctx->buf_len += len;
91 	}
92 }
93 
94 
95 static void
96 pad_message(struct crypt_s390_sha1_ctx* sctx)
97 {
98 	int index;
99 
100 	index = sctx->buf_len;
101 	sctx->buf_len = (sctx->buf_len < 56)?
102 		SHA1_BLOCK_SIZE:2 * SHA1_BLOCK_SIZE;
103 	//start pad with 1
104 	sctx->buffer[index] = 0x80;
105 	//pad with zeros
106 	index++;
107 	memset(sctx->buffer + index, 0x00, sctx->buf_len - index);
108 	//append length
109 	memcpy(sctx->buffer + sctx->buf_len - 8, &sctx->count,
110 			sizeof sctx->count);
111 }
112 
113 /* Add padding and return the message digest. */
114 static void sha1_final(struct crypto_tfm *tfm, u8 *out)
115 {
116 	struct crypt_s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
117 
118 	//must perform manual padding
119 	pad_message(sctx);
120 	crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer, sctx->buf_len);
121 	//copy digest to out
122 	memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
123 	/* Wipe context */
124 	memset(sctx, 0, sizeof *sctx);
125 }
126 
127 static struct crypto_alg alg = {
128 	.cra_name	=	"sha1",
129 	.cra_driver_name =	"sha1-s390",
130 	.cra_priority	=	CRYPT_S390_PRIORITY,
131 	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
132 	.cra_blocksize	=	SHA1_BLOCK_SIZE,
133 	.cra_ctxsize	=	sizeof(struct crypt_s390_sha1_ctx),
134 	.cra_module	=	THIS_MODULE,
135 	.cra_list       =       LIST_HEAD_INIT(alg.cra_list),
136 	.cra_u		=	{ .digest = {
137 	.dia_digestsize	=	SHA1_DIGEST_SIZE,
138 	.dia_init   	= 	sha1_init,
139 	.dia_update 	=	sha1_update,
140 	.dia_final  	=	sha1_final } }
141 };
142 
143 static int
144 init(void)
145 {
146 	int ret = -ENOSYS;
147 
148 	if (crypt_s390_func_available(KIMD_SHA_1)){
149 		ret = crypto_register_alg(&alg);
150 		if (ret == 0){
151 			printk(KERN_INFO "crypt_s390: sha1_s390 loaded.\n");
152 		}
153 	}
154 	return ret;
155 }
156 
157 static void __exit
158 fini(void)
159 {
160 	crypto_unregister_alg(&alg);
161 }
162 
163 module_init(init);
164 module_exit(fini);
165 
166 MODULE_ALIAS("sha1");
167 
168 MODULE_LICENSE("GPL");
169 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
170