xref: /openbmc/linux/arch/s390/crypto/sha1_s390.c (revision 87c2ce3b)
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
44 sha1_init(void *ctx)
45 {
46 	static const struct crypt_s390_sha1_ctx initstate = {
47 		.state = {
48 			0x67452301,
49 			0xEFCDAB89,
50 			0x98BADCFE,
51 			0x10325476,
52 			0xC3D2E1F0
53 		},
54 	};
55 	memcpy(ctx, &initstate, sizeof(initstate));
56 }
57 
58 static void
59 sha1_update(void *ctx, const u8 *data, unsigned int len)
60 {
61 	struct crypt_s390_sha1_ctx *sctx;
62 	long imd_len;
63 
64 	sctx = ctx;
65 	sctx->count += len * 8; //message bit length
66 
67 	//anything in buffer yet? -> must be completed
68 	if (sctx->buf_len && (sctx->buf_len + len) >= SHA1_BLOCK_SIZE) {
69 		//complete full block and hash
70 		memcpy(sctx->buffer + sctx->buf_len, data,
71 				SHA1_BLOCK_SIZE - sctx->buf_len);
72 		crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer,
73 				SHA1_BLOCK_SIZE);
74 		data += SHA1_BLOCK_SIZE - sctx->buf_len;
75 		len -= SHA1_BLOCK_SIZE - sctx->buf_len;
76 		sctx->buf_len = 0;
77 	}
78 
79 	//rest of data contains full blocks?
80 	imd_len = len & ~0x3ful;
81 	if (imd_len){
82 		crypt_s390_kimd(KIMD_SHA_1, sctx->state, data, imd_len);
83 		data += imd_len;
84 		len -= imd_len;
85 	}
86 	//anything left? store in buffer
87 	if (len){
88 		memcpy(sctx->buffer + sctx->buf_len , data, len);
89 		sctx->buf_len += len;
90 	}
91 }
92 
93 
94 static void
95 pad_message(struct crypt_s390_sha1_ctx* sctx)
96 {
97 	int index;
98 
99 	index = sctx->buf_len;
100 	sctx->buf_len = (sctx->buf_len < 56)?
101 		SHA1_BLOCK_SIZE:2 * SHA1_BLOCK_SIZE;
102 	//start pad with 1
103 	sctx->buffer[index] = 0x80;
104 	//pad with zeros
105 	index++;
106 	memset(sctx->buffer + index, 0x00, sctx->buf_len - index);
107 	//append length
108 	memcpy(sctx->buffer + sctx->buf_len - 8, &sctx->count,
109 			sizeof sctx->count);
110 }
111 
112 /* Add padding and return the message digest. */
113 static void
114 sha1_final(void* ctx, u8 *out)
115 {
116 	struct crypt_s390_sha1_ctx *sctx = ctx;
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_flags	=	CRYPTO_ALG_TYPE_DIGEST,
130 	.cra_blocksize	=	SHA1_BLOCK_SIZE,
131 	.cra_ctxsize	=	sizeof(struct crypt_s390_sha1_ctx),
132 	.cra_module	=	THIS_MODULE,
133 	.cra_list       =       LIST_HEAD_INIT(alg.cra_list),
134 	.cra_u		=	{ .digest = {
135 	.dia_digestsize	=	SHA1_DIGEST_SIZE,
136 	.dia_init   	= 	sha1_init,
137 	.dia_update 	=	sha1_update,
138 	.dia_final  	=	sha1_final } }
139 };
140 
141 static int
142 init(void)
143 {
144 	int ret = -ENOSYS;
145 
146 	if (crypt_s390_func_available(KIMD_SHA_1)){
147 		ret = crypto_register_alg(&alg);
148 		if (ret == 0){
149 			printk(KERN_INFO "crypt_s390: sha1_s390 loaded.\n");
150 		}
151 	}
152 	return ret;
153 }
154 
155 static void __exit
156 fini(void)
157 {
158 	crypto_unregister_alg(&alg);
159 }
160 
161 module_init(init);
162 module_exit(fini);
163 
164 MODULE_ALIAS("sha1");
165 
166 MODULE_LICENSE("GPL");
167 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
168