des3_ede_glue.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Glue Code for assembler optimized version of 3DES
  4 *
  5 * Copyright © 2014 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
  6 *
  7 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
  8 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
  9 */
 10
 11#include <crypto/algapi.h>
 12#include <crypto/des.h>
 13#include <crypto/internal/skcipher.h>
 14#include <linux/crypto.h>
 15#include <linux/init.h>
 16#include <linux/module.h>
 17#include <linux/types.h>
 18
 19struct des3_ede_x86_ctx {
 20	struct des3_ede_ctx enc;
 21	struct des3_ede_ctx dec;
 22};
 23
 24/* regular block cipher functions */
 25asmlinkage void des3_ede_x86_64_crypt_blk(const u32 *expkey, u8 *dst,
 26					  const u8 *src);
 27
 28/* 3-way parallel cipher functions */
 29asmlinkage void des3_ede_x86_64_crypt_blk_3way(const u32 *expkey, u8 *dst,
 30					       const u8 *src);
 31
 32static inline void des3_ede_enc_blk(struct des3_ede_x86_ctx *ctx, u8 *dst,
 33				    const u8 *src)
 34{
 35	u32 *enc_ctx = ctx->enc.expkey;
 36
 37	des3_ede_x86_64_crypt_blk(enc_ctx, dst, src);
 38}
 39
 40static inline void des3_ede_dec_blk(struct des3_ede_x86_ctx *ctx, u8 *dst,
 41				    const u8 *src)
 42{
 43	u32 *dec_ctx = ctx->dec.expkey;
 44
 45	des3_ede_x86_64_crypt_blk(dec_ctx, dst, src);
 46}
 47
 48static inline void des3_ede_dec_blk_3way(struct des3_ede_x86_ctx *ctx, u8 *dst,
 49					 const u8 *src)
 50{
 51	u32 *dec_ctx = ctx->dec.expkey;
 52
 53	des3_ede_x86_64_crypt_blk_3way(dec_ctx, dst, src);
 54}
 55
 56static void des3_ede_x86_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
 57{
 58	des3_ede_enc_blk(crypto_tfm_ctx(tfm), dst, src);
 59}
 60
 61static void des3_ede_x86_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
 62{
 63	des3_ede_dec_blk(crypto_tfm_ctx(tfm), dst, src);
 64}
 65
 66static int ecb_crypt(struct skcipher_request *req, const u32 *expkey)
 67{
 68	const unsigned int bsize = DES3_EDE_BLOCK_SIZE;
 69	struct skcipher_walk walk;
 70	unsigned int nbytes;
 71	int err;
 72
 73	err = skcipher_walk_virt(&walk, req, false);
 74
 75	while ((nbytes = walk.nbytes)) {
 76		const u8 *wsrc = walk.src.virt.addr;
 77		u8 *wdst = walk.dst.virt.addr;
 78
 79		/* Process four block batch */
 80		if (nbytes >= bsize * 3) {
 81			do {
 82				des3_ede_x86_64_crypt_blk_3way(expkey, wdst,
 83							       wsrc);
 84
 85				wsrc += bsize * 3;
 86				wdst += bsize * 3;
 87				nbytes -= bsize * 3;
 88			} while (nbytes >= bsize * 3);
 89
 90			if (nbytes < bsize)
 91				goto done;
 92		}
 93
 94		/* Handle leftovers */
 95		do {
 96			des3_ede_x86_64_crypt_blk(expkey, wdst, wsrc);
 97
 98			wsrc += bsize;
 99			wdst += bsize;
100			nbytes -= bsize;
101		} while (nbytes >= bsize);
102
103done:
104		err = skcipher_walk_done(&walk, nbytes);
105	}
106
107	return err;
108}
109
110static int ecb_encrypt(struct skcipher_request *req)
111{
112	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
113	struct des3_ede_x86_ctx *ctx = crypto_skcipher_ctx(tfm);
114
115	return ecb_crypt(req, ctx->enc.expkey);
116}
117
118static int ecb_decrypt(struct skcipher_request *req)
119{
120	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
121	struct des3_ede_x86_ctx *ctx = crypto_skcipher_ctx(tfm);
122
123	return ecb_crypt(req, ctx->dec.expkey);
124}
125
126static unsigned int __cbc_encrypt(struct des3_ede_x86_ctx *ctx,
127				  struct skcipher_walk *walk)
128{
129	unsigned int bsize = DES3_EDE_BLOCK_SIZE;
130	unsigned int nbytes = walk->nbytes;
131	u64 *src = (u64 *)walk->src.virt.addr;
132	u64 *dst = (u64 *)walk->dst.virt.addr;
133	u64 *iv = (u64 *)walk->iv;
134
135	do {
136		*dst = *src ^ *iv;
137		des3_ede_enc_blk(ctx, (u8 *)dst, (u8 *)dst);
138		iv = dst;
139
140		src += 1;
141		dst += 1;
142		nbytes -= bsize;
143	} while (nbytes >= bsize);
144
145	*(u64 *)walk->iv = *iv;
146	return nbytes;
147}
148
149static int cbc_encrypt(struct skcipher_request *req)
150{
151	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
152	struct des3_ede_x86_ctx *ctx = crypto_skcipher_ctx(tfm);
153	struct skcipher_walk walk;
154	unsigned int nbytes;
155	int err;
156
157	err = skcipher_walk_virt(&walk, req, false);
158
159	while (walk.nbytes) {
160		nbytes = __cbc_encrypt(ctx, &walk);
161		err = skcipher_walk_done(&walk, nbytes);
162	}
163
164	return err;
165}
166
167static unsigned int __cbc_decrypt(struct des3_ede_x86_ctx *ctx,
168				  struct skcipher_walk *walk)
169{
170	unsigned int bsize = DES3_EDE_BLOCK_SIZE;
171	unsigned int nbytes = walk->nbytes;
172	u64 *src = (u64 *)walk->src.virt.addr;
173	u64 *dst = (u64 *)walk->dst.virt.addr;
174	u64 ivs[3 - 1];
175	u64 last_iv;
176
177	/* Start of the last block. */
178	src += nbytes / bsize - 1;
179	dst += nbytes / bsize - 1;
180
181	last_iv = *src;
182
183	/* Process four block batch */
184	if (nbytes >= bsize * 3) {
185		do {
186			nbytes -= bsize * 3 - bsize;
187			src -= 3 - 1;
188			dst -= 3 - 1;
189
190			ivs[0] = src[0];
191			ivs[1] = src[1];
192
193			des3_ede_dec_blk_3way(ctx, (u8 *)dst, (u8 *)src);
194
195			dst[1] ^= ivs[0];
196			dst[2] ^= ivs[1];
197
198			nbytes -= bsize;
199			if (nbytes < bsize)
200				goto done;
201
202			*dst ^= *(src - 1);
203			src -= 1;
204			dst -= 1;
205		} while (nbytes >= bsize * 3);
206	}
207
208	/* Handle leftovers */
209	for (;;) {
210		des3_ede_dec_blk(ctx, (u8 *)dst, (u8 *)src);
211
212		nbytes -= bsize;
213		if (nbytes < bsize)
214			break;
215
216		*dst ^= *(src - 1);
217		src -= 1;
218		dst -= 1;
219	}
220
221done:
222	*dst ^= *(u64 *)walk->iv;
223	*(u64 *)walk->iv = last_iv;
224
225	return nbytes;
226}
227
228static int cbc_decrypt(struct skcipher_request *req)
229{
230	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
231	struct des3_ede_x86_ctx *ctx = crypto_skcipher_ctx(tfm);
232	struct skcipher_walk walk;
233	unsigned int nbytes;
234	int err;
235
236	err = skcipher_walk_virt(&walk, req, false);
237
238	while (walk.nbytes) {
239		nbytes = __cbc_decrypt(ctx, &walk);
240		err = skcipher_walk_done(&walk, nbytes);
241	}
242
243	return err;
244}
245
246static int des3_ede_x86_setkey(struct crypto_tfm *tfm, const u8 *key,
247			       unsigned int keylen)
248{
249	struct des3_ede_x86_ctx *ctx = crypto_tfm_ctx(tfm);
250	u32 i, j, tmp;
251	int err;
252
253	err = des3_ede_expand_key(&ctx->enc, key, keylen);
254	if (err == -ENOKEY) {
255		if (crypto_tfm_get_flags(tfm) & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)
256			err = -EINVAL;
257		else
258			err = 0;
259	}
260
261	if (err) {
262		memset(ctx, 0, sizeof(*ctx));
263		return err;
264	}
265
266	/* Fix encryption context for this implementation and form decryption
267	 * context. */
268	j = DES3_EDE_EXPKEY_WORDS - 2;
269	for (i = 0; i < DES3_EDE_EXPKEY_WORDS; i += 2, j -= 2) {
270		tmp = ror32(ctx->enc.expkey[i + 1], 4);
271		ctx->enc.expkey[i + 1] = tmp;
272
273		ctx->dec.expkey[j + 0] = ctx->enc.expkey[i + 0];
274		ctx->dec.expkey[j + 1] = tmp;
275	}
276
277	return 0;
278}
279
280static int des3_ede_x86_setkey_skcipher(struct crypto_skcipher *tfm,
281					const u8 *key,
282					unsigned int keylen)
283{
284	return des3_ede_x86_setkey(&tfm->base, key, keylen);
285}
286
287static struct crypto_alg des3_ede_cipher = {
288	.cra_name		= "des3_ede",
289	.cra_driver_name	= "des3_ede-asm",
290	.cra_priority		= 200,
291	.cra_flags		= CRYPTO_ALG_TYPE_CIPHER,
292	.cra_blocksize		= DES3_EDE_BLOCK_SIZE,
293	.cra_ctxsize		= sizeof(struct des3_ede_x86_ctx),
294	.cra_module		= THIS_MODULE,
295	.cra_u = {
296		.cipher = {
297			.cia_min_keysize	= DES3_EDE_KEY_SIZE,
298			.cia_max_keysize	= DES3_EDE_KEY_SIZE,
299			.cia_setkey		= des3_ede_x86_setkey,
300			.cia_encrypt		= des3_ede_x86_encrypt,
301			.cia_decrypt		= des3_ede_x86_decrypt,
302		}
303	}
304};
305
306static struct skcipher_alg des3_ede_skciphers[] = {
307	{
308		.base.cra_name		= "ecb(des3_ede)",
309		.base.cra_driver_name	= "ecb-des3_ede-asm",
310		.base.cra_priority	= 300,
311		.base.cra_blocksize	= DES3_EDE_BLOCK_SIZE,
312		.base.cra_ctxsize	= sizeof(struct des3_ede_x86_ctx),
313		.base.cra_module	= THIS_MODULE,
314		.min_keysize		= DES3_EDE_KEY_SIZE,
315		.max_keysize		= DES3_EDE_KEY_SIZE,
316		.setkey			= des3_ede_x86_setkey_skcipher,
317		.encrypt		= ecb_encrypt,
318		.decrypt		= ecb_decrypt,
319	}, {
320		.base.cra_name		= "cbc(des3_ede)",
321		.base.cra_driver_name	= "cbc-des3_ede-asm",
322		.base.cra_priority	= 300,
323		.base.cra_blocksize	= DES3_EDE_BLOCK_SIZE,
324		.base.cra_ctxsize	= sizeof(struct des3_ede_x86_ctx),
325		.base.cra_module	= THIS_MODULE,
326		.min_keysize		= DES3_EDE_KEY_SIZE,
327		.max_keysize		= DES3_EDE_KEY_SIZE,
328		.ivsize			= DES3_EDE_BLOCK_SIZE,
329		.setkey			= des3_ede_x86_setkey_skcipher,
330		.encrypt		= cbc_encrypt,
331		.decrypt		= cbc_decrypt,
332	}
333};
334
335static bool is_blacklisted_cpu(void)
336{
337	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
338		return false;
339
340	if (boot_cpu_data.x86 == 0x0f) {
341		/*
342		 * On Pentium 4, des3_ede-x86_64 is slower than generic C
343		 * implementation because use of 64bit rotates (which are really
344		 * slow on P4). Therefore blacklist P4s.
345		 */
346		return true;
347	}
348
349	return false;
350}
351
352static int force;
353module_param(force, int, 0);
354MODULE_PARM_DESC(force, "Force module load, ignore CPU blacklist");
355
356static int __init des3_ede_x86_init(void)
357{
358	int err;
359
360	if (!force && is_blacklisted_cpu()) {
361		pr_info("des3_ede-x86_64: performance on this CPU would be suboptimal: disabling des3_ede-x86_64.\n");
362		return -ENODEV;
363	}
364
365	err = crypto_register_alg(&des3_ede_cipher);
366	if (err)
367		return err;
368
369	err = crypto_register_skciphers(des3_ede_skciphers,
370					ARRAY_SIZE(des3_ede_skciphers));
371	if (err)
372		crypto_unregister_alg(&des3_ede_cipher);
373
374	return err;
375}
376
377static void __exit des3_ede_x86_fini(void)
378{
379	crypto_unregister_alg(&des3_ede_cipher);
380	crypto_unregister_skciphers(des3_ede_skciphers,
381				    ARRAY_SIZE(des3_ede_skciphers));
382}
383
384module_init(des3_ede_x86_init);
385module_exit(des3_ede_x86_fini);
386
387MODULE_LICENSE("GPL");
388MODULE_DESCRIPTION("Triple DES EDE Cipher Algorithm, asm optimized");
389MODULE_ALIAS_CRYPTO("des3_ede");
390MODULE_ALIAS_CRYPTO("des3_ede-asm");
391MODULE_AUTHOR("Jussi Kivilinna <jussi.kivilinna@iki.fi>");