xref: /openbmc/linux/arch/s390/crypto/sha1_s390.c (revision a1e58bbd)
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_generic.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 #include <crypto/sha.h>
30 
31 #include "crypt_s390.h"
32 
33 struct s390_sha1_ctx {
34 	u64 count;		/* message length */
35 	u32 state[5];
36 	u8 buf[2 * SHA1_BLOCK_SIZE];
37 };
38 
39 static void sha1_init(struct crypto_tfm *tfm)
40 {
41 	struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
42 
43 	sctx->state[0] = SHA1_H0;
44 	sctx->state[1] = SHA1_H1;
45 	sctx->state[2] = SHA1_H2;
46 	sctx->state[3] = SHA1_H3;
47 	sctx->state[4] = SHA1_H4;
48 	sctx->count = 0;
49 }
50 
51 static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
52 			unsigned int len)
53 {
54 	struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
55 	unsigned int index;
56 	int ret;
57 
58 	/* how much is already in the buffer? */
59 	index = sctx->count & 0x3f;
60 
61 	sctx->count += len;
62 
63 	if (index + len < SHA1_BLOCK_SIZE)
64 		goto store;
65 
66 	/* process one stored block */
67 	if (index) {
68 		memcpy(sctx->buf + index, data, SHA1_BLOCK_SIZE - index);
69 		ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf,
70 				      SHA1_BLOCK_SIZE);
71 		BUG_ON(ret != SHA1_BLOCK_SIZE);
72 		data += SHA1_BLOCK_SIZE - index;
73 		len -= SHA1_BLOCK_SIZE - index;
74 	}
75 
76 	/* process as many blocks as possible */
77 	if (len >= SHA1_BLOCK_SIZE) {
78 		ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, data,
79 				      len & ~(SHA1_BLOCK_SIZE - 1));
80 		BUG_ON(ret != (len & ~(SHA1_BLOCK_SIZE - 1)));
81 		data += ret;
82 		len -= ret;
83 	}
84 
85 store:
86 	/* anything left? */
87 	if (len)
88 		memcpy(sctx->buf + index , data, len);
89 }
90 
91 /* Add padding and return the message digest. */
92 static void sha1_final(struct crypto_tfm *tfm, u8 *out)
93 {
94 	struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
95 	u64 bits;
96 	unsigned int index, end;
97 	int ret;
98 
99 	/* must perform manual padding */
100 	index = sctx->count & 0x3f;
101 	end =  (index < 56) ? SHA1_BLOCK_SIZE : (2 * SHA1_BLOCK_SIZE);
102 
103 	/* start pad with 1 */
104 	sctx->buf[index] = 0x80;
105 
106 	/* pad with zeros */
107 	index++;
108 	memset(sctx->buf + index, 0x00, end - index - 8);
109 
110 	/* append message length */
111 	bits = sctx->count * 8;
112 	memcpy(sctx->buf + end - 8, &bits, sizeof(bits));
113 
114 	ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf, end);
115 	BUG_ON(ret != end);
116 
117 	/* copy digest to out */
118 	memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
119 
120 	/* wipe context */
121 	memset(sctx, 0, sizeof *sctx);
122 }
123 
124 static struct crypto_alg alg = {
125 	.cra_name	=	"sha1",
126 	.cra_driver_name=	"sha1-s390",
127 	.cra_priority	=	CRYPT_S390_PRIORITY,
128 	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
129 	.cra_blocksize	=	SHA1_BLOCK_SIZE,
130 	.cra_ctxsize	=	sizeof(struct s390_sha1_ctx),
131 	.cra_module	=	THIS_MODULE,
132 	.cra_list	=	LIST_HEAD_INIT(alg.cra_list),
133 	.cra_u		=	{ .digest = {
134 	.dia_digestsize	=	SHA1_DIGEST_SIZE,
135 	.dia_init	=	sha1_init,
136 	.dia_update	=	sha1_update,
137 	.dia_final	=	sha1_final } }
138 };
139 
140 static int __init init(void)
141 {
142 	if (!crypt_s390_func_available(KIMD_SHA_1))
143 		return -EOPNOTSUPP;
144 
145 	return crypto_register_alg(&alg);
146 }
147 
148 static void __exit fini(void)
149 {
150 	crypto_unregister_alg(&alg);
151 }
152 
153 module_init(init);
154 module_exit(fini);
155 
156 MODULE_ALIAS("sha1");
157 
158 MODULE_LICENSE("GPL");
159 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
160