1/*
2 * Glue Code for assembler optimized version of 3DES
3 *
4 * Copyright © 2014 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
5 *
6 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
7 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
8 * CTR part based on code (crypto/ctr.c) by:
9 *   (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 * GNU General Public License for more details.
20 *
21 */
22
23#include <asm/processor.h>
24#include <crypto/des.h>
25#include <linux/crypto.h>
26#include <linux/init.h>
27#include <linux/module.h>
28#include <linux/types.h>
29#include <crypto/algapi.h>
30
31struct des3_ede_x86_ctx {
32	u32 enc_expkey[DES3_EDE_EXPKEY_WORDS];
33	u32 dec_expkey[DES3_EDE_EXPKEY_WORDS];
34};
35
36/* regular block cipher functions */
37asmlinkage void des3_ede_x86_64_crypt_blk(const u32 *expkey, u8 *dst,
38					  const u8 *src);
39
40/* 3-way parallel cipher functions */
41asmlinkage void des3_ede_x86_64_crypt_blk_3way(const u32 *expkey, u8 *dst,
42					       const u8 *src);
43
44static inline void des3_ede_enc_blk(struct des3_ede_x86_ctx *ctx, u8 *dst,
45				    const u8 *src)
46{
47	u32 *enc_ctx = ctx->enc_expkey;
48
49	des3_ede_x86_64_crypt_blk(enc_ctx, dst, src);
50}
51
52static inline void des3_ede_dec_blk(struct des3_ede_x86_ctx *ctx, u8 *dst,
53				    const u8 *src)
54{
55	u32 *dec_ctx = ctx->dec_expkey;
56
57	des3_ede_x86_64_crypt_blk(dec_ctx, dst, src);
58}
59
60static inline void des3_ede_enc_blk_3way(struct des3_ede_x86_ctx *ctx, u8 *dst,
61					 const u8 *src)
62{
63	u32 *enc_ctx = ctx->enc_expkey;
64
65	des3_ede_x86_64_crypt_blk_3way(enc_ctx, dst, src);
66}
67
68static inline void des3_ede_dec_blk_3way(struct des3_ede_x86_ctx *ctx, u8 *dst,
69					 const u8 *src)
70{
71	u32 *dec_ctx = ctx->dec_expkey;
72
73	des3_ede_x86_64_crypt_blk_3way(dec_ctx, dst, src);
74}
75
76static void des3_ede_x86_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
77{
78	des3_ede_enc_blk(crypto_tfm_ctx(tfm), dst, src);
79}
80
81static void des3_ede_x86_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
82{
83	des3_ede_dec_blk(crypto_tfm_ctx(tfm), dst, src);
84}
85
86static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
87		     const u32 *expkey)
88{
89	unsigned int bsize = DES3_EDE_BLOCK_SIZE;
90	unsigned int nbytes;
91	int err;
92
93	err = blkcipher_walk_virt(desc, walk);
94
95	while ((nbytes = walk->nbytes)) {
96		u8 *wsrc = walk->src.virt.addr;
97		u8 *wdst = walk->dst.virt.addr;
98
99		/* Process four block batch */
100		if (nbytes >= bsize * 3) {
101			do {
102				des3_ede_x86_64_crypt_blk_3way(expkey, wdst,
103							       wsrc);
104
105				wsrc += bsize * 3;
106				wdst += bsize * 3;
107				nbytes -= bsize * 3;
108			} while (nbytes >= bsize * 3);
109
110			if (nbytes < bsize)
111				goto done;
112		}
113
114		/* Handle leftovers */
115		do {
116			des3_ede_x86_64_crypt_blk(expkey, wdst, wsrc);
117
118			wsrc += bsize;
119			wdst += bsize;
120			nbytes -= bsize;
121		} while (nbytes >= bsize);
122
123done:
124		err = blkcipher_walk_done(desc, walk, nbytes);
125	}
126
127	return err;
128}
129
130static int ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
131		       struct scatterlist *src, unsigned int nbytes)
132{
133	struct des3_ede_x86_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
134	struct blkcipher_walk walk;
135
136	blkcipher_walk_init(&walk, dst, src, nbytes);
137	return ecb_crypt(desc, &walk, ctx->enc_expkey);
138}
139
140static int ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
141		       struct scatterlist *src, unsigned int nbytes)
142{
143	struct des3_ede_x86_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
144	struct blkcipher_walk walk;
145
146	blkcipher_walk_init(&walk, dst, src, nbytes);
147	return ecb_crypt(desc, &walk, ctx->dec_expkey);
148}
149
150static unsigned int __cbc_encrypt(struct blkcipher_desc *desc,
151				  struct blkcipher_walk *walk)
152{
153	struct des3_ede_x86_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
154	unsigned int bsize = DES3_EDE_BLOCK_SIZE;
155	unsigned int nbytes = walk->nbytes;
156	u64 *src = (u64 *)walk->src.virt.addr;
157	u64 *dst = (u64 *)walk->dst.virt.addr;
158	u64 *iv = (u64 *)walk->iv;
159
160	do {
161		*dst = *src ^ *iv;
162		des3_ede_enc_blk(ctx, (u8 *)dst, (u8 *)dst);
163		iv = dst;
164
165		src += 1;
166		dst += 1;
167		nbytes -= bsize;
168	} while (nbytes >= bsize);
169
170	*(u64 *)walk->iv = *iv;
171	return nbytes;
172}
173
174static int cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
175		       struct scatterlist *src, unsigned int nbytes)
176{
177	struct blkcipher_walk walk;
178	int err;
179
180	blkcipher_walk_init(&walk, dst, src, nbytes);
181	err = blkcipher_walk_virt(desc, &walk);
182
183	while ((nbytes = walk.nbytes)) {
184		nbytes = __cbc_encrypt(desc, &walk);
185		err = blkcipher_walk_done(desc, &walk, nbytes);
186	}
187
188	return err;
189}
190
191static unsigned int __cbc_decrypt(struct blkcipher_desc *desc,
192				  struct blkcipher_walk *walk)
193{
194	struct des3_ede_x86_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
195	unsigned int bsize = DES3_EDE_BLOCK_SIZE;
196	unsigned int nbytes = walk->nbytes;
197	u64 *src = (u64 *)walk->src.virt.addr;
198	u64 *dst = (u64 *)walk->dst.virt.addr;
199	u64 ivs[3 - 1];
200	u64 last_iv;
201
202	/* Start of the last block. */
203	src += nbytes / bsize - 1;
204	dst += nbytes / bsize - 1;
205
206	last_iv = *src;
207
208	/* Process four block batch */
209	if (nbytes >= bsize * 3) {
210		do {
211			nbytes -= bsize * 3 - bsize;
212			src -= 3 - 1;
213			dst -= 3 - 1;
214
215			ivs[0] = src[0];
216			ivs[1] = src[1];
217
218			des3_ede_dec_blk_3way(ctx, (u8 *)dst, (u8 *)src);
219
220			dst[1] ^= ivs[0];
221			dst[2] ^= ivs[1];
222
223			nbytes -= bsize;
224			if (nbytes < bsize)
225				goto done;
226
227			*dst ^= *(src - 1);
228			src -= 1;
229			dst -= 1;
230		} while (nbytes >= bsize * 3);
231	}
232
233	/* Handle leftovers */
234	for (;;) {
235		des3_ede_dec_blk(ctx, (u8 *)dst, (u8 *)src);
236
237		nbytes -= bsize;
238		if (nbytes < bsize)
239			break;
240
241		*dst ^= *(src - 1);
242		src -= 1;
243		dst -= 1;
244	}
245
246done:
247	*dst ^= *(u64 *)walk->iv;
248	*(u64 *)walk->iv = last_iv;
249
250	return nbytes;
251}
252
253static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
254		       struct scatterlist *src, unsigned int nbytes)
255{
256	struct blkcipher_walk walk;
257	int err;
258
259	blkcipher_walk_init(&walk, dst, src, nbytes);
260	err = blkcipher_walk_virt(desc, &walk);
261
262	while ((nbytes = walk.nbytes)) {
263		nbytes = __cbc_decrypt(desc, &walk);
264		err = blkcipher_walk_done(desc, &walk, nbytes);
265	}
266
267	return err;
268}
269
270static void ctr_crypt_final(struct des3_ede_x86_ctx *ctx,
271			    struct blkcipher_walk *walk)
272{
273	u8 *ctrblk = walk->iv;
274	u8 keystream[DES3_EDE_BLOCK_SIZE];
275	u8 *src = walk->src.virt.addr;
276	u8 *dst = walk->dst.virt.addr;
277	unsigned int nbytes = walk->nbytes;
278
279	des3_ede_enc_blk(ctx, keystream, ctrblk);
280	crypto_xor(keystream, src, nbytes);
281	memcpy(dst, keystream, nbytes);
282
283	crypto_inc(ctrblk, DES3_EDE_BLOCK_SIZE);
284}
285
286static unsigned int __ctr_crypt(struct blkcipher_desc *desc,
287				struct blkcipher_walk *walk)
288{
289	struct des3_ede_x86_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
290	unsigned int bsize = DES3_EDE_BLOCK_SIZE;
291	unsigned int nbytes = walk->nbytes;
292	__be64 *src = (__be64 *)walk->src.virt.addr;
293	__be64 *dst = (__be64 *)walk->dst.virt.addr;
294	u64 ctrblk = be64_to_cpu(*(__be64 *)walk->iv);
295	__be64 ctrblocks[3];
296
297	/* Process four block batch */
298	if (nbytes >= bsize * 3) {
299		do {
300			/* create ctrblks for parallel encrypt */
301			ctrblocks[0] = cpu_to_be64(ctrblk++);
302			ctrblocks[1] = cpu_to_be64(ctrblk++);
303			ctrblocks[2] = cpu_to_be64(ctrblk++);
304
305			des3_ede_enc_blk_3way(ctx, (u8 *)ctrblocks,
306					      (u8 *)ctrblocks);
307
308			dst[0] = src[0] ^ ctrblocks[0];
309			dst[1] = src[1] ^ ctrblocks[1];
310			dst[2] = src[2] ^ ctrblocks[2];
311
312			src += 3;
313			dst += 3;
314		} while ((nbytes -= bsize * 3) >= bsize * 3);
315
316		if (nbytes < bsize)
317			goto done;
318	}
319
320	/* Handle leftovers */
321	do {
322		ctrblocks[0] = cpu_to_be64(ctrblk++);
323
324		des3_ede_enc_blk(ctx, (u8 *)ctrblocks, (u8 *)ctrblocks);
325
326		dst[0] = src[0] ^ ctrblocks[0];
327
328		src += 1;
329		dst += 1;
330	} while ((nbytes -= bsize) >= bsize);
331
332done:
333	*(__be64 *)walk->iv = cpu_to_be64(ctrblk);
334	return nbytes;
335}
336
337static int ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
338		     struct scatterlist *src, unsigned int nbytes)
339{
340	struct blkcipher_walk walk;
341	int err;
342
343	blkcipher_walk_init(&walk, dst, src, nbytes);
344	err = blkcipher_walk_virt_block(desc, &walk, DES3_EDE_BLOCK_SIZE);
345
346	while ((nbytes = walk.nbytes) >= DES3_EDE_BLOCK_SIZE) {
347		nbytes = __ctr_crypt(desc, &walk);
348		err = blkcipher_walk_done(desc, &walk, nbytes);
349	}
350
351	if (walk.nbytes) {
352		ctr_crypt_final(crypto_blkcipher_ctx(desc->tfm), &walk);
353		err = blkcipher_walk_done(desc, &walk, 0);
354	}
355
356	return err;
357}
358
359static int des3_ede_x86_setkey(struct crypto_tfm *tfm, const u8 *key,
360			       unsigned int keylen)
361{
362	struct des3_ede_x86_ctx *ctx = crypto_tfm_ctx(tfm);
363	u32 i, j, tmp;
364	int err;
365
366	/* Generate encryption context using generic implementation. */
367	err = __des3_ede_setkey(ctx->enc_expkey, &tfm->crt_flags, key, keylen);
368	if (err < 0)
369		return err;
370
371	/* Fix encryption context for this implementation and form decryption
372	 * context. */
373	j = DES3_EDE_EXPKEY_WORDS - 2;
374	for (i = 0; i < DES3_EDE_EXPKEY_WORDS; i += 2, j -= 2) {
375		tmp = ror32(ctx->enc_expkey[i + 1], 4);
376		ctx->enc_expkey[i + 1] = tmp;
377
378		ctx->dec_expkey[j + 0] = ctx->enc_expkey[i + 0];
379		ctx->dec_expkey[j + 1] = tmp;
380	}
381
382	return 0;
383}
384
385static struct crypto_alg des3_ede_algs[4] = { {
386	.cra_name		= "des3_ede",
387	.cra_driver_name	= "des3_ede-asm",
388	.cra_priority		= 200,
389	.cra_flags		= CRYPTO_ALG_TYPE_CIPHER,
390	.cra_blocksize		= DES3_EDE_BLOCK_SIZE,
391	.cra_ctxsize		= sizeof(struct des3_ede_x86_ctx),
392	.cra_alignmask		= 0,
393	.cra_module		= THIS_MODULE,
394	.cra_u = {
395		.cipher = {
396			.cia_min_keysize	= DES3_EDE_KEY_SIZE,
397			.cia_max_keysize	= DES3_EDE_KEY_SIZE,
398			.cia_setkey		= des3_ede_x86_setkey,
399			.cia_encrypt		= des3_ede_x86_encrypt,
400			.cia_decrypt		= des3_ede_x86_decrypt,
401		}
402	}
403}, {
404	.cra_name		= "ecb(des3_ede)",
405	.cra_driver_name	= "ecb-des3_ede-asm",
406	.cra_priority		= 300,
407	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
408	.cra_blocksize		= DES3_EDE_BLOCK_SIZE,
409	.cra_ctxsize		= sizeof(struct des3_ede_x86_ctx),
410	.cra_alignmask		= 0,
411	.cra_type		= &crypto_blkcipher_type,
412	.cra_module		= THIS_MODULE,
413	.cra_u = {
414		.blkcipher = {
415			.min_keysize	= DES3_EDE_KEY_SIZE,
416			.max_keysize	= DES3_EDE_KEY_SIZE,
417			.setkey		= des3_ede_x86_setkey,
418			.encrypt	= ecb_encrypt,
419			.decrypt	= ecb_decrypt,
420		},
421	},
422}, {
423	.cra_name		= "cbc(des3_ede)",
424	.cra_driver_name	= "cbc-des3_ede-asm",
425	.cra_priority		= 300,
426	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
427	.cra_blocksize		= DES3_EDE_BLOCK_SIZE,
428	.cra_ctxsize		= sizeof(struct des3_ede_x86_ctx),
429	.cra_alignmask		= 0,
430	.cra_type		= &crypto_blkcipher_type,
431	.cra_module		= THIS_MODULE,
432	.cra_u = {
433		.blkcipher = {
434			.min_keysize	= DES3_EDE_KEY_SIZE,
435			.max_keysize	= DES3_EDE_KEY_SIZE,
436			.ivsize		= DES3_EDE_BLOCK_SIZE,
437			.setkey		= des3_ede_x86_setkey,
438			.encrypt	= cbc_encrypt,
439			.decrypt	= cbc_decrypt,
440		},
441	},
442}, {
443	.cra_name		= "ctr(des3_ede)",
444	.cra_driver_name	= "ctr-des3_ede-asm",
445	.cra_priority		= 300,
446	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
447	.cra_blocksize		= 1,
448	.cra_ctxsize		= sizeof(struct des3_ede_x86_ctx),
449	.cra_alignmask		= 0,
450	.cra_type		= &crypto_blkcipher_type,
451	.cra_module		= THIS_MODULE,
452	.cra_u = {
453		.blkcipher = {
454			.min_keysize	= DES3_EDE_KEY_SIZE,
455			.max_keysize	= DES3_EDE_KEY_SIZE,
456			.ivsize		= DES3_EDE_BLOCK_SIZE,
457			.setkey		= des3_ede_x86_setkey,
458			.encrypt	= ctr_crypt,
459			.decrypt	= ctr_crypt,
460		},
461	},
462} };
463
464static bool is_blacklisted_cpu(void)
465{
466	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
467		return false;
468
469	if (boot_cpu_data.x86 == 0x0f) {
470		/*
471		 * On Pentium 4, des3_ede-x86_64 is slower than generic C
472		 * implementation because use of 64bit rotates (which are really
473		 * slow on P4). Therefore blacklist P4s.
474		 */
475		return true;
476	}
477
478	return false;
479}
480
481static int force;
482module_param(force, int, 0);
483MODULE_PARM_DESC(force, "Force module load, ignore CPU blacklist");
484
485static int __init des3_ede_x86_init(void)
486{
487	if (!force && is_blacklisted_cpu()) {
488		pr_info("des3_ede-x86_64: performance on this CPU would be suboptimal: disabling des3_ede-x86_64.\n");
489		return -ENODEV;
490	}
491
492	return crypto_register_algs(des3_ede_algs, ARRAY_SIZE(des3_ede_algs));
493}
494
495static void __exit des3_ede_x86_fini(void)
496{
497	crypto_unregister_algs(des3_ede_algs, ARRAY_SIZE(des3_ede_algs));
498}
499
500module_init(des3_ede_x86_init);
501module_exit(des3_ede_x86_fini);
502
503MODULE_LICENSE("GPL");
504MODULE_DESCRIPTION("Triple DES EDE Cipher Algorithm, asm optimized");
505MODULE_ALIAS_CRYPTO("des3_ede");
506MODULE_ALIAS_CRYPTO("des3_ede-asm");
507MODULE_AUTHOR("Jussi Kivilinna <jussi.kivilinna@iki.fi>");
508