aboutsummaryrefslogtreecommitdiff
path: root/drivers/crypto/padlock-sha.c
blob: fb6e6c34314895c48ec8c21206661986ffe9ec79 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
/*
 * Cryptographic API.
 *
 * Support for VIA PadLock hardware crypto engine.
 *
 * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */

#include <crypto/internal/hash.h>
#include <crypto/sha.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
#include <asm/i387.h>
#include "padlock.h"

struct padlock_sha_desc {
	struct shash_desc fallback;
};

struct padlock_sha_ctx {
	struct crypto_shash *fallback;
};

static int padlock_sha_init(struct shash_desc *desc)
{
	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);

	dctx->fallback.tfm = ctx->fallback;
	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
	return crypto_shash_init(&dctx->fallback);
}

static int padlock_sha_update(struct shash_desc *desc,
			      const u8 *data, unsigned int length)
{
	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);

	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
	return crypto_shash_update(&dctx->fallback, data, length);
}

static inline void padlock_output_block(uint32_t *src,
		 	uint32_t *dst, size_t count)
{
	while (count--)
		*dst++ = swab32(*src++);
}

static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
			      unsigned int count, u8 *out)
{
	/* We can't store directly to *out as it may be unaligned. */
	/* BTW Don't reduce the buffer size below 128 Bytes!
	 *     PadLock microcode needs it that big. */
	char result[128] __attribute__ ((aligned(PADLOCK_ALIGNMENT)));
	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
	struct sha1_state state;
	unsigned int space;
	unsigned int leftover;
	int ts_state;
	int err;

	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
	err = crypto_shash_export(&dctx->fallback, &state);
	if (err)
		goto out;

	if (state.count + count > ULONG_MAX)
		return crypto_shash_finup(&dctx->fallback, in, count, out);

	leftover = ((state.count - 1) & (SHA1_BLOCK_SIZE - 1)) + 1;
	space =  SHA1_BLOCK_SIZE - leftover;
	if (space) {
		if (count > space) {
			err = crypto_shash_update(&dctx->fallback, in, space) ?:
			      crypto_shash_export(&dctx->fallback, &state);
			if (err)
				goto out;
			count -= space;
			in += space;
		} else {
			memcpy(state.buffer + leftover, in, count);
			in = state.buffer;
			count += leftover;
		}
	}

	memcpy(result, &state.state, SHA1_DIGEST_SIZE);

	/* prevent taking the spurious DNA fault with padlock. */
	ts_state = irq_ts_save();
	asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
		      : \
		      : "c"(state.count + count), "a"(state.count), \
			"S"(in), "D"(result));
	irq_ts_restore(ts_state);

	padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);

out:
	return err;
}

static int padlock_sha1_final(struct shash_desc *desc, u8 *out)
{
	u8 buf[4];

	return padlock_sha1_finup(desc, buf, 0, out);
}

static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
				unsigned int count, u8 *out)
{
	/* We can't store directly to *out as it may be unaligned. */
	/* BTW Don't reduce the buffer size below 128 Bytes!
	 *     PadLock microcode needs it that big. */
	char result[128] __attribute__ ((aligned(PADLOCK_ALIGNMENT)));
	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
	struct sha256_state state;
	unsigned int space;
	unsigned int leftover;
	int ts_state;
	int err;

	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
	err = crypto_shash_export(&dctx->fallback, &state);
	if (err)
		goto out;

	if (state.count + count > ULONG_MAX)
		return crypto_shash_finup(&dctx->fallback, in, count, out);

	leftover = ((state.count - 1) & (SHA256_BLOCK_SIZE - 1)) + 1;
	space =  SHA256_BLOCK_SIZE - leftover;
	if (space) {
		if (count > space) {
			err = crypto_shash_update(&dctx->fallback, in, space) ?:
			      crypto_shash_export(&dctx->fallback, &state);
			if (err)
				goto out;
			count -= space;
			in += space;
		} else {
			memcpy(state.buf + leftover, in, count);
			in = state.buf;
			count += leftover;
		}
	}

	memcpy(result, &state.state, SHA256_DIGEST_SIZE);

	/* prevent taking the spurious DNA fault with padlock. */
	ts_state = irq_ts_save();
	asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
		      : \
		      : "c"(state.count + count), "a"(state.count), \
			"S"(in), "D"(result));
	irq_ts_restore(ts_state);

	padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);

out:
	return err;
}

static int padlock_sha256_final(struct shash_desc *desc, u8 *out)
{
	u8 buf[4];

	return padlock_sha256_finup(desc, buf, 0, out);
}

static int padlock_cra_init(struct crypto_tfm *tfm)
{
	struct crypto_shash *hash = __crypto_shash_cast(tfm);
	const char *fallback_driver_name = tfm->__crt_alg->cra_name;
	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_shash *fallback_tfm;
	int err = -ENOMEM;

	/* Allocate a fallback and abort if it failed. */
	fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
					  CRYPTO_ALG_NEED_FALLBACK);
	if (IS_ERR(fallback_tfm)) {
		printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
		       fallback_driver_name);
		err = PTR_ERR(fallback_tfm);
		goto out;
	}

	ctx->fallback = fallback_tfm;
	hash->descsize += crypto_shash_descsize(fallback_tfm);
	return 0;

out:
	return err;
}

static void padlock_cra_exit(struct crypto_tfm *tfm)
{
	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);

	crypto_free_shash(ctx->fallback);
}

static struct shash_alg sha1_alg = {
	.digestsize	=	SHA1_DIGEST_SIZE,
	.init   	= 	padlock_sha_init,
	.update 	=	padlock_sha_update,
	.finup  	=	padlock_sha1_finup,
	.final  	=	padlock_sha1_final,
	.descsize	=	sizeof(struct padlock_sha_desc),
	.base		=	{
		.cra_name		=	"sha1",
		.cra_driver_name	=	"sha1-padlock",
		.cra_priority		=	PADLOCK_CRA_PRIORITY,
		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH |
						CRYPTO_ALG_NEED_FALLBACK,
		.cra_blocksize		=	SHA1_BLOCK_SIZE,
		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
		.cra_module		=	THIS_MODULE,
		.cra_init		=	padlock_cra_init,
		.cra_exit		=	padlock_cra_exit,
	}
};

static struct shash_alg sha256_alg = {
	.digestsize	=	SHA256_DIGEST_SIZE,
	.init   	= 	padlock_sha_init,
	.update 	=	padlock_sha_update,
	.finup  	=	padlock_sha256_finup,
	.final  	=	padlock_sha256_final,
	.descsize	=	sizeof(struct padlock_sha_desc),
	.base		=	{
		.cra_name		=	"sha256",
		.cra_driver_name	=	"sha256-padlock",
		.cra_priority		=	PADLOCK_CRA_PRIORITY,
		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH |
						CRYPTO_ALG_NEED_FALLBACK,
		.cra_blocksize		=	SHA256_BLOCK_SIZE,
		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
		.cra_module		=	THIS_MODULE,
		.cra_init		=	padlock_cra_init,
		.cra_exit		=	padlock_cra_exit,
	}
};

static int __init padlock_init(void)
{
	int rc = -ENODEV;

	if (!cpu_has_phe) {
		printk(KERN_NOTICE PFX "VIA PadLock Hash Engine not detected.\n");
		return -ENODEV;
	}

	if (!cpu_has_phe_enabled) {
		printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
		return -ENODEV;
	}

	rc = crypto_register_shash(&sha1_alg);
	if (rc)
		goto out;

	rc = crypto_register_shash(&sha256_alg);
	if (rc)
		goto out_unreg1;

	printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");

	return 0;

out_unreg1:
	crypto_unregister_shash(&sha1_alg);
out:
	printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
	return rc;
}

static void __exit padlock_fini(void)
{
	crypto_unregister_shash(&sha1_alg);
	crypto_unregister_shash(&sha256_alg);
}

module_init(padlock_init);
module_exit(padlock_fini);

MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michal Ludvig");

MODULE_ALIAS("sha1-all");
MODULE_ALIAS("sha256-all");
MODULE_ALIAS("sha1-padlock");
MODULE_ALIAS("sha256-padlock");