xref: /openbmc/linux/arch/s390/crypto/sha1_s390.c (revision 64c70b1c)
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 
35 struct s390_sha1_ctx {
36 	u64 count;		/* message length */
37 	u32 state[5];
38 	u8 buf[2 * SHA1_BLOCK_SIZE];
39 };
40 
41 static 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 
53 static 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 
87 store:
88 	/* anything left? */
89 	if (len)
90 		memcpy(sctx->buf + index , data, len);
91 }
92 
93 /* Add padding and return the message digest. */
94 static 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 
126 static 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 
142 static 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 
150 static void __exit fini(void)
151 {
152 	crypto_unregister_alg(&alg);
153 }
154 
155 module_init(init);
156 module_exit(fini);
157 
158 MODULE_ALIAS("sha1");
159 
160 MODULE_LICENSE("GPL");
161 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
162