1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Cryptographic API.
4  *
5  * SHA1 Secure Hash Algorithm.
6  *
7  * Adapted for OCTEON by Aaro Koskinen <aaro.koskinen@iki.fi>.
8  *
9  * Based on crypto/sha1_generic.c, which is:
10  *
11  * Copyright (c) Alan Smithee.
12  * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
13  * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
14  */
15 
16 #include <linux/mm.h>
17 #include <crypto/sha1.h>
18 #include <crypto/sha1_base.h>
19 #include <linux/init.h>
20 #include <linux/types.h>
21 #include <linux/module.h>
22 #include <asm/byteorder.h>
23 #include <asm/octeon/octeon.h>
24 #include <crypto/internal/hash.h>
25 
26 #include "octeon-crypto.h"
27 
28 /*
29  * We pass everything as 64-bit. OCTEON can handle misaligned data.
30  */
31 
32 static void octeon_sha1_store_hash(struct sha1_state *sctx)
33 {
34 	u64 *hash = (u64 *)sctx->state;
35 	union {
36 		u32 word[2];
37 		u64 dword;
38 	} hash_tail = { { sctx->state[4], } };
39 
40 	write_octeon_64bit_hash_dword(hash[0], 0);
41 	write_octeon_64bit_hash_dword(hash[1], 1);
42 	write_octeon_64bit_hash_dword(hash_tail.dword, 2);
43 	memzero_explicit(&hash_tail.word[0], sizeof(hash_tail.word[0]));
44 }
45 
46 static void octeon_sha1_read_hash(struct sha1_state *sctx)
47 {
48 	u64 *hash = (u64 *)sctx->state;
49 	union {
50 		u32 word[2];
51 		u64 dword;
52 	} hash_tail;
53 
54 	hash[0]		= read_octeon_64bit_hash_dword(0);
55 	hash[1]		= read_octeon_64bit_hash_dword(1);
56 	hash_tail.dword	= read_octeon_64bit_hash_dword(2);
57 	sctx->state[4]	= hash_tail.word[0];
58 	memzero_explicit(&hash_tail.dword, sizeof(hash_tail.dword));
59 }
60 
61 static void octeon_sha1_transform(const void *_block)
62 {
63 	const u64 *block = _block;
64 
65 	write_octeon_64bit_block_dword(block[0], 0);
66 	write_octeon_64bit_block_dword(block[1], 1);
67 	write_octeon_64bit_block_dword(block[2], 2);
68 	write_octeon_64bit_block_dword(block[3], 3);
69 	write_octeon_64bit_block_dword(block[4], 4);
70 	write_octeon_64bit_block_dword(block[5], 5);
71 	write_octeon_64bit_block_dword(block[6], 6);
72 	octeon_sha1_start(block[7]);
73 }
74 
75 static void __octeon_sha1_update(struct sha1_state *sctx, const u8 *data,
76 				 unsigned int len)
77 {
78 	unsigned int partial;
79 	unsigned int done;
80 	const u8 *src;
81 
82 	partial = sctx->count % SHA1_BLOCK_SIZE;
83 	sctx->count += len;
84 	done = 0;
85 	src = data;
86 
87 	if ((partial + len) >= SHA1_BLOCK_SIZE) {
88 		if (partial) {
89 			done = -partial;
90 			memcpy(sctx->buffer + partial, data,
91 			       done + SHA1_BLOCK_SIZE);
92 			src = sctx->buffer;
93 		}
94 
95 		do {
96 			octeon_sha1_transform(src);
97 			done += SHA1_BLOCK_SIZE;
98 			src = data + done;
99 		} while (done + SHA1_BLOCK_SIZE <= len);
100 
101 		partial = 0;
102 	}
103 	memcpy(sctx->buffer + partial, src, len - done);
104 }
105 
106 static int octeon_sha1_update(struct shash_desc *desc, const u8 *data,
107 			unsigned int len)
108 {
109 	struct sha1_state *sctx = shash_desc_ctx(desc);
110 	struct octeon_cop2_state state;
111 	unsigned long flags;
112 
113 	/*
114 	 * Small updates never reach the crypto engine, so the generic sha1 is
115 	 * faster because of the heavyweight octeon_crypto_enable() /
116 	 * octeon_crypto_disable().
117 	 */
118 	if ((sctx->count % SHA1_BLOCK_SIZE) + len < SHA1_BLOCK_SIZE)
119 		return crypto_sha1_update(desc, data, len);
120 
121 	flags = octeon_crypto_enable(&state);
122 	octeon_sha1_store_hash(sctx);
123 
124 	__octeon_sha1_update(sctx, data, len);
125 
126 	octeon_sha1_read_hash(sctx);
127 	octeon_crypto_disable(&state, flags);
128 
129 	return 0;
130 }
131 
132 static int octeon_sha1_final(struct shash_desc *desc, u8 *out)
133 {
134 	struct sha1_state *sctx = shash_desc_ctx(desc);
135 	static const u8 padding[64] = { 0x80, };
136 	struct octeon_cop2_state state;
137 	__be32 *dst = (__be32 *)out;
138 	unsigned int pad_len;
139 	unsigned long flags;
140 	unsigned int index;
141 	__be64 bits;
142 	int i;
143 
144 	/* Save number of bits. */
145 	bits = cpu_to_be64(sctx->count << 3);
146 
147 	/* Pad out to 56 mod 64. */
148 	index = sctx->count & 0x3f;
149 	pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
150 
151 	flags = octeon_crypto_enable(&state);
152 	octeon_sha1_store_hash(sctx);
153 
154 	__octeon_sha1_update(sctx, padding, pad_len);
155 
156 	/* Append length (before padding). */
157 	__octeon_sha1_update(sctx, (const u8 *)&bits, sizeof(bits));
158 
159 	octeon_sha1_read_hash(sctx);
160 	octeon_crypto_disable(&state, flags);
161 
162 	/* Store state in digest */
163 	for (i = 0; i < 5; i++)
164 		dst[i] = cpu_to_be32(sctx->state[i]);
165 
166 	/* Zeroize sensitive information. */
167 	memset(sctx, 0, sizeof(*sctx));
168 
169 	return 0;
170 }
171 
172 static int octeon_sha1_export(struct shash_desc *desc, void *out)
173 {
174 	struct sha1_state *sctx = shash_desc_ctx(desc);
175 
176 	memcpy(out, sctx, sizeof(*sctx));
177 	return 0;
178 }
179 
180 static int octeon_sha1_import(struct shash_desc *desc, const void *in)
181 {
182 	struct sha1_state *sctx = shash_desc_ctx(desc);
183 
184 	memcpy(sctx, in, sizeof(*sctx));
185 	return 0;
186 }
187 
188 static struct shash_alg octeon_sha1_alg = {
189 	.digestsize	=	SHA1_DIGEST_SIZE,
190 	.init		=	sha1_base_init,
191 	.update		=	octeon_sha1_update,
192 	.final		=	octeon_sha1_final,
193 	.export		=	octeon_sha1_export,
194 	.import		=	octeon_sha1_import,
195 	.descsize	=	sizeof(struct sha1_state),
196 	.statesize	=	sizeof(struct sha1_state),
197 	.base		=	{
198 		.cra_name	=	"sha1",
199 		.cra_driver_name=	"octeon-sha1",
200 		.cra_priority	=	OCTEON_CR_OPCODE_PRIORITY,
201 		.cra_blocksize	=	SHA1_BLOCK_SIZE,
202 		.cra_module	=	THIS_MODULE,
203 	}
204 };
205 
206 static int __init octeon_sha1_mod_init(void)
207 {
208 	if (!octeon_has_crypto())
209 		return -ENOTSUPP;
210 	return crypto_register_shash(&octeon_sha1_alg);
211 }
212 
213 static void __exit octeon_sha1_mod_fini(void)
214 {
215 	crypto_unregister_shash(&octeon_sha1_alg);
216 }
217 
218 module_init(octeon_sha1_mod_init);
219 module_exit(octeon_sha1_mod_fini);
220 
221 MODULE_LICENSE("GPL");
222 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm (OCTEON)");
223 MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
224