Free Electrons

Embedded Linux Experts

  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
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
/*
 * Glue Code for assembler optimized version of Blowfish
 *
 * Copyright (c) 2011 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
 *
 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 * CTR part based on code (crypto/ctr.c) by:
 *   (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 *
 */

#include <asm/processor.h>
#include <crypto/blowfish.h>
#include <linux/crypto.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <crypto/algapi.h>

/* regular block cipher functions */
asmlinkage void __blowfish_enc_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src,
				   bool xor);
asmlinkage void blowfish_dec_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);

/* 4-way parallel cipher functions */
asmlinkage void __blowfish_enc_blk_4way(struct bf_ctx *ctx, u8 *dst,
					const u8 *src, bool xor);
asmlinkage void blowfish_dec_blk_4way(struct bf_ctx *ctx, u8 *dst,
				      const u8 *src);

static inline void blowfish_enc_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src)
{
	__blowfish_enc_blk(ctx, dst, src, false);
}

static inline void blowfish_enc_blk_xor(struct bf_ctx *ctx, u8 *dst,
					const u8 *src)
{
	__blowfish_enc_blk(ctx, dst, src, true);
}

static inline void blowfish_enc_blk_4way(struct bf_ctx *ctx, u8 *dst,
					 const u8 *src)
{
	__blowfish_enc_blk_4way(ctx, dst, src, false);
}

static inline void blowfish_enc_blk_xor_4way(struct bf_ctx *ctx, u8 *dst,
				      const u8 *src)
{
	__blowfish_enc_blk_4way(ctx, dst, src, true);
}

static void blowfish_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	blowfish_enc_blk(crypto_tfm_ctx(tfm), dst, src);
}

static void blowfish_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	blowfish_dec_blk(crypto_tfm_ctx(tfm), dst, src);
}

static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
		     void (*fn)(struct bf_ctx *, u8 *, const u8 *),
		     void (*fn_4way)(struct bf_ctx *, u8 *, const u8 *))
{
	struct bf_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	unsigned int bsize = BF_BLOCK_SIZE;
	unsigned int nbytes;
	int err;

	err = blkcipher_walk_virt(desc, walk);

	while ((nbytes = walk->nbytes)) {
		u8 *wsrc = walk->src.virt.addr;
		u8 *wdst = walk->dst.virt.addr;

		/* Process four block batch */
		if (nbytes >= bsize * 4) {
			do {
				fn_4way(ctx, wdst, wsrc);

				wsrc += bsize * 4;
				wdst += bsize * 4;
				nbytes -= bsize * 4;
			} while (nbytes >= bsize * 4);

			if (nbytes < bsize)
				goto done;
		}

		/* Handle leftovers */
		do {
			fn(ctx, wdst, wsrc);

			wsrc += bsize;
			wdst += bsize;
			nbytes -= bsize;
		} while (nbytes >= bsize);

done:
		err = blkcipher_walk_done(desc, walk, nbytes);
	}

	return err;
}

static int ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct blkcipher_walk walk;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	return ecb_crypt(desc, &walk, blowfish_enc_blk, blowfish_enc_blk_4way);
}

static int ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct blkcipher_walk walk;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	return ecb_crypt(desc, &walk, blowfish_dec_blk, blowfish_dec_blk_4way);
}

static unsigned int __cbc_encrypt(struct blkcipher_desc *desc,
				  struct blkcipher_walk *walk)
{
	struct bf_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	unsigned int bsize = BF_BLOCK_SIZE;
	unsigned int nbytes = walk->nbytes;
	u64 *src = (u64 *)walk->src.virt.addr;
	u64 *dst = (u64 *)walk->dst.virt.addr;
	u64 *iv = (u64 *)walk->iv;

	do {
		*dst = *src ^ *iv;
		blowfish_enc_blk(ctx, (u8 *)dst, (u8 *)dst);
		iv = dst;

		src += 1;
		dst += 1;
		nbytes -= bsize;
	} while (nbytes >= bsize);

	*(u64 *)walk->iv = *iv;
	return nbytes;
}

static int cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
		nbytes = __cbc_encrypt(desc, &walk);
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
}

static unsigned int __cbc_decrypt(struct blkcipher_desc *desc,
				  struct blkcipher_walk *walk)
{
	struct bf_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	unsigned int bsize = BF_BLOCK_SIZE;
	unsigned int nbytes = walk->nbytes;
	u64 *src = (u64 *)walk->src.virt.addr;
	u64 *dst = (u64 *)walk->dst.virt.addr;
	u64 ivs[4 - 1];
	u64 last_iv;

	/* Start of the last block. */
	src += nbytes / bsize - 1;
	dst += nbytes / bsize - 1;

	last_iv = *src;

	/* Process four block batch */
	if (nbytes >= bsize * 4) {
		do {
			nbytes -= bsize * 4 - bsize;
			src -= 4 - 1;
			dst -= 4 - 1;

			ivs[0] = src[0];
			ivs[1] = src[1];
			ivs[2] = src[2];

			blowfish_dec_blk_4way(ctx, (u8 *)dst, (u8 *)src);

			dst[1] ^= ivs[0];
			dst[2] ^= ivs[1];
			dst[3] ^= ivs[2];

			nbytes -= bsize;
			if (nbytes < bsize)
				goto done;

			*dst ^= *(src - 1);
			src -= 1;
			dst -= 1;
		} while (nbytes >= bsize * 4);
	}

	/* Handle leftovers */
	for (;;) {
		blowfish_dec_blk(ctx, (u8 *)dst, (u8 *)src);

		nbytes -= bsize;
		if (nbytes < bsize)
			break;

		*dst ^= *(src - 1);
		src -= 1;
		dst -= 1;
	}

done:
	*dst ^= *(u64 *)walk->iv;
	*(u64 *)walk->iv = last_iv;

	return nbytes;
}

static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
		nbytes = __cbc_decrypt(desc, &walk);
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
}

static void ctr_crypt_final(struct bf_ctx *ctx, struct blkcipher_walk *walk)
{
	u8 *ctrblk = walk->iv;
	u8 keystream[BF_BLOCK_SIZE];
	u8 *src = walk->src.virt.addr;
	u8 *dst = walk->dst.virt.addr;
	unsigned int nbytes = walk->nbytes;

	blowfish_enc_blk(ctx, keystream, ctrblk);
	crypto_xor_cpy(dst, keystream, src, nbytes);

	crypto_inc(ctrblk, BF_BLOCK_SIZE);
}

static unsigned int __ctr_crypt(struct blkcipher_desc *desc,
				struct blkcipher_walk *walk)
{
	struct bf_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	unsigned int bsize = BF_BLOCK_SIZE;
	unsigned int nbytes = walk->nbytes;
	u64 *src = (u64 *)walk->src.virt.addr;
	u64 *dst = (u64 *)walk->dst.virt.addr;
	u64 ctrblk = be64_to_cpu(*(__be64 *)walk->iv);
	__be64 ctrblocks[4];

	/* Process four block batch */
	if (nbytes >= bsize * 4) {
		do {
			if (dst != src) {
				dst[0] = src[0];
				dst[1] = src[1];
				dst[2] = src[2];
				dst[3] = src[3];
			}

			/* create ctrblks for parallel encrypt */
			ctrblocks[0] = cpu_to_be64(ctrblk++);
			ctrblocks[1] = cpu_to_be64(ctrblk++);
			ctrblocks[2] = cpu_to_be64(ctrblk++);
			ctrblocks[3] = cpu_to_be64(ctrblk++);

			blowfish_enc_blk_xor_4way(ctx, (u8 *)dst,
						  (u8 *)ctrblocks);

			src += 4;
			dst += 4;
		} while ((nbytes -= bsize * 4) >= bsize * 4);

		if (nbytes < bsize)
			goto done;
	}

	/* Handle leftovers */
	do {
		if (dst != src)
			*dst = *src;

		ctrblocks[0] = cpu_to_be64(ctrblk++);

		blowfish_enc_blk_xor(ctx, (u8 *)dst, (u8 *)ctrblocks);

		src += 1;
		dst += 1;
	} while ((nbytes -= bsize) >= bsize);

done:
	*(__be64 *)walk->iv = cpu_to_be64(ctrblk);
	return nbytes;
}

static int ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		     struct scatterlist *src, unsigned int nbytes)
{
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt_block(desc, &walk, BF_BLOCK_SIZE);

	while ((nbytes = walk.nbytes) >= BF_BLOCK_SIZE) {
		nbytes = __ctr_crypt(desc, &walk);
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	if (walk.nbytes) {
		ctr_crypt_final(crypto_blkcipher_ctx(desc->tfm), &walk);
		err = blkcipher_walk_done(desc, &walk, 0);
	}

	return err;
}

static struct crypto_alg bf_algs[4] = { {
	.cra_name		= "blowfish",
	.cra_driver_name	= "blowfish-asm",
	.cra_priority		= 200,
	.cra_flags		= CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		= BF_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct bf_ctx),
	.cra_alignmask		= 0,
	.cra_module		= THIS_MODULE,
	.cra_u = {
		.cipher = {
			.cia_min_keysize	= BF_MIN_KEY_SIZE,
			.cia_max_keysize	= BF_MAX_KEY_SIZE,
			.cia_setkey		= blowfish_setkey,
			.cia_encrypt		= blowfish_encrypt,
			.cia_decrypt		= blowfish_decrypt,
		}
	}
}, {
	.cra_name		= "ecb(blowfish)",
	.cra_driver_name	= "ecb-blowfish-asm",
	.cra_priority		= 300,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= BF_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct bf_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_u = {
		.blkcipher = {
			.min_keysize	= BF_MIN_KEY_SIZE,
			.max_keysize	= BF_MAX_KEY_SIZE,
			.setkey		= blowfish_setkey,
			.encrypt	= ecb_encrypt,
			.decrypt	= ecb_decrypt,
		},
	},
}, {
	.cra_name		= "cbc(blowfish)",
	.cra_driver_name	= "cbc-blowfish-asm",
	.cra_priority		= 300,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= BF_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct bf_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_u = {
		.blkcipher = {
			.min_keysize	= BF_MIN_KEY_SIZE,
			.max_keysize	= BF_MAX_KEY_SIZE,
			.ivsize		= BF_BLOCK_SIZE,
			.setkey		= blowfish_setkey,
			.encrypt	= cbc_encrypt,
			.decrypt	= cbc_decrypt,
		},
	},
}, {
	.cra_name		= "ctr(blowfish)",
	.cra_driver_name	= "ctr-blowfish-asm",
	.cra_priority		= 300,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= 1,
	.cra_ctxsize		= sizeof(struct bf_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_u = {
		.blkcipher = {
			.min_keysize	= BF_MIN_KEY_SIZE,
			.max_keysize	= BF_MAX_KEY_SIZE,
			.ivsize		= BF_BLOCK_SIZE,
			.setkey		= blowfish_setkey,
			.encrypt	= ctr_crypt,
			.decrypt	= ctr_crypt,
		},
	},
} };

static bool is_blacklisted_cpu(void)
{
	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
		return false;

	if (boot_cpu_data.x86 == 0x0f) {
		/*
		 * On Pentium 4, blowfish-x86_64 is slower than generic C
		 * implementation because use of 64bit rotates (which are really
		 * slow on P4). Therefore blacklist P4s.
		 */
		return true;
	}

	return false;
}

static int force;
module_param(force, int, 0);
MODULE_PARM_DESC(force, "Force module load, ignore CPU blacklist");

static int __init init(void)
{
	if (!force && is_blacklisted_cpu()) {
		printk(KERN_INFO
			"blowfish-x86_64: performance on this CPU "
			"would be suboptimal: disabling "
			"blowfish-x86_64.\n");
		return -ENODEV;
	}

	return crypto_register_algs(bf_algs, ARRAY_SIZE(bf_algs));
}

static void __exit fini(void)
{
	crypto_unregister_algs(bf_algs, ARRAY_SIZE(bf_algs));
}

module_init(init);
module_exit(fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Blowfish Cipher Algorithm, asm optimized");
MODULE_ALIAS_CRYPTO("blowfish");
MODULE_ALIAS_CRYPTO("blowfish-asm");