1/*
2 * Cryptographic API.
3 *
4 * SHA1 Secure Hash Algorithm.
5 *
6 * Adapted for OCTEON by Aaro Koskinen <aaro.koskinen@iki.fi>.
7 *
8 * Based on crypto/sha1_generic.c, which is:
9 *
10 * Copyright (c) Alan Smithee.
11 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
12 * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
13 *
14 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the Free
16 * Software Foundation; either version 2 of the License, or (at your option)
17 * any later version.
18 */
19
20#include <linux/mm.h>
21#include <crypto/sha.h>
22#include <linux/init.h>
23#include <linux/types.h>
24#include <linux/module.h>
25#include <asm/byteorder.h>
26#include <asm/octeon/octeon.h>
27#include <crypto/internal/hash.h>
28
29#include "octeon-crypto.h"
30
31/*
32 * We pass everything as 64-bit. OCTEON can handle misaligned data.
33 */
34
35static void octeon_sha1_store_hash(struct sha1_state *sctx)
36{
37	u64 *hash = (u64 *)sctx->state;
38	union {
39		u32 word[2];
40		u64 dword;
41	} hash_tail = { { sctx->state[4], } };
42
43	write_octeon_64bit_hash_dword(hash[0], 0);
44	write_octeon_64bit_hash_dword(hash[1], 1);
45	write_octeon_64bit_hash_dword(hash_tail.dword, 2);
46	memzero_explicit(&hash_tail.word[0], sizeof(hash_tail.word[0]));
47}
48
49static void octeon_sha1_read_hash(struct sha1_state *sctx)
50{
51	u64 *hash = (u64 *)sctx->state;
52	union {
53		u32 word[2];
54		u64 dword;
55	} hash_tail;
56
57	hash[0]		= read_octeon_64bit_hash_dword(0);
58	hash[1]		= read_octeon_64bit_hash_dword(1);
59	hash_tail.dword	= read_octeon_64bit_hash_dword(2);
60	sctx->state[4]	= hash_tail.word[0];
61	memzero_explicit(&hash_tail.dword, sizeof(hash_tail.dword));
62}
63
64static void octeon_sha1_transform(const void *_block)
65{
66	const u64 *block = _block;
67
68	write_octeon_64bit_block_dword(block[0], 0);
69	write_octeon_64bit_block_dword(block[1], 1);
70	write_octeon_64bit_block_dword(block[2], 2);
71	write_octeon_64bit_block_dword(block[3], 3);
72	write_octeon_64bit_block_dword(block[4], 4);
73	write_octeon_64bit_block_dword(block[5], 5);
74	write_octeon_64bit_block_dword(block[6], 6);
75	octeon_sha1_start(block[7]);
76}
77
78static int octeon_sha1_init(struct shash_desc *desc)
79{
80	struct sha1_state *sctx = shash_desc_ctx(desc);
81
82	sctx->state[0] = SHA1_H0;
83	sctx->state[1] = SHA1_H1;
84	sctx->state[2] = SHA1_H2;
85	sctx->state[3] = SHA1_H3;
86	sctx->state[4] = SHA1_H4;
87	sctx->count = 0;
88
89	return 0;
90}
91
92static void __octeon_sha1_update(struct sha1_state *sctx, const u8 *data,
93				 unsigned int len)
94{
95	unsigned int partial;
96	unsigned int done;
97	const u8 *src;
98
99	partial = sctx->count % SHA1_BLOCK_SIZE;
100	sctx->count += len;
101	done = 0;
102	src = data;
103
104	if ((partial + len) >= SHA1_BLOCK_SIZE) {
105		if (partial) {
106			done = -partial;
107			memcpy(sctx->buffer + partial, data,
108			       done + SHA1_BLOCK_SIZE);
109			src = sctx->buffer;
110		}
111
112		do {
113			octeon_sha1_transform(src);
114			done += SHA1_BLOCK_SIZE;
115			src = data + done;
116		} while (done + SHA1_BLOCK_SIZE <= len);
117
118		partial = 0;
119	}
120	memcpy(sctx->buffer + partial, src, len - done);
121}
122
123static int octeon_sha1_update(struct shash_desc *desc, const u8 *data,
124			unsigned int len)
125{
126	struct sha1_state *sctx = shash_desc_ctx(desc);
127	struct octeon_cop2_state state;
128	unsigned long flags;
129
130	/*
131	 * Small updates never reach the crypto engine, so the generic sha1 is
132	 * faster because of the heavyweight octeon_crypto_enable() /
133	 * octeon_crypto_disable().
134	 */
135	if ((sctx->count % SHA1_BLOCK_SIZE) + len < SHA1_BLOCK_SIZE)
136		return crypto_sha1_update(desc, data, len);
137
138	flags = octeon_crypto_enable(&state);
139	octeon_sha1_store_hash(sctx);
140
141	__octeon_sha1_update(sctx, data, len);
142
143	octeon_sha1_read_hash(sctx);
144	octeon_crypto_disable(&state, flags);
145
146	return 0;
147}
148
149static int octeon_sha1_final(struct shash_desc *desc, u8 *out)
150{
151	struct sha1_state *sctx = shash_desc_ctx(desc);
152	static const u8 padding[64] = { 0x80, };
153	struct octeon_cop2_state state;
154	__be32 *dst = (__be32 *)out;
155	unsigned int pad_len;
156	unsigned long flags;
157	unsigned int index;
158	__be64 bits;
159	int i;
160
161	/* Save number of bits. */
162	bits = cpu_to_be64(sctx->count << 3);
163
164	/* Pad out to 56 mod 64. */
165	index = sctx->count & 0x3f;
166	pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
167
168	flags = octeon_crypto_enable(&state);
169	octeon_sha1_store_hash(sctx);
170
171	__octeon_sha1_update(sctx, padding, pad_len);
172
173	/* Append length (before padding). */
174	__octeon_sha1_update(sctx, (const u8 *)&bits, sizeof(bits));
175
176	octeon_sha1_read_hash(sctx);
177	octeon_crypto_disable(&state, flags);
178
179	/* Store state in digest */
180	for (i = 0; i < 5; i++)
181		dst[i] = cpu_to_be32(sctx->state[i]);
182
183	/* Zeroize sensitive information. */
184	memset(sctx, 0, sizeof(*sctx));
185
186	return 0;
187}
188
189static int octeon_sha1_export(struct shash_desc *desc, void *out)
190{
191	struct sha1_state *sctx = shash_desc_ctx(desc);
192
193	memcpy(out, sctx, sizeof(*sctx));
194	return 0;
195}
196
197static int octeon_sha1_import(struct shash_desc *desc, const void *in)
198{
199	struct sha1_state *sctx = shash_desc_ctx(desc);
200
201	memcpy(sctx, in, sizeof(*sctx));
202	return 0;
203}
204
205static struct shash_alg octeon_sha1_alg = {
206	.digestsize	=	SHA1_DIGEST_SIZE,
207	.init		=	octeon_sha1_init,
208	.update		=	octeon_sha1_update,
209	.final		=	octeon_sha1_final,
210	.export		=	octeon_sha1_export,
211	.import		=	octeon_sha1_import,
212	.descsize	=	sizeof(struct sha1_state),
213	.statesize	=	sizeof(struct sha1_state),
214	.base		=	{
215		.cra_name	=	"sha1",
216		.cra_driver_name=	"octeon-sha1",
217		.cra_priority	=	OCTEON_CR_OPCODE_PRIORITY,
218		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
219		.cra_blocksize	=	SHA1_BLOCK_SIZE,
220		.cra_module	=	THIS_MODULE,
221	}
222};
223
224static int __init octeon_sha1_mod_init(void)
225{
226	if (!octeon_has_crypto())
227		return -ENOTSUPP;
228	return crypto_register_shash(&octeon_sha1_alg);
229}
230
231static void __exit octeon_sha1_mod_fini(void)
232{
233	crypto_unregister_shash(&octeon_sha1_alg);
234}
235
236module_init(octeon_sha1_mod_init);
237module_exit(octeon_sha1_mod_fini);
238
239MODULE_LICENSE("GPL");
240MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm (OCTEON)");
241MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
242