xref: /linux/arch/s390/crypto/des_s390.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Cryptographic API.
4  *
5  * s390 implementation of the DES Cipher Algorithm.
6  *
7  * Copyright IBM Corp. 2003, 2011
8  * Author(s): Thomas Spatzier
9  *	      Jan Glauber (jan.glauber@de.ibm.com)
10  */
11 
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/cpufeature.h>
15 #include <linux/crypto.h>
16 #include <linux/fips.h>
17 #include <linux/mutex.h>
18 #include <crypto/algapi.h>
19 #include <crypto/internal/des.h>
20 #include <crypto/internal/skcipher.h>
21 #include <asm/cpacf.h>
22 
23 #define DES3_KEY_SIZE	(3 * DES_KEY_SIZE)
24 
25 static u8 *ctrblk;
26 static DEFINE_MUTEX(ctrblk_lock);
27 
28 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
29 
30 struct s390_des_ctx {
31 	u8 iv[DES_BLOCK_SIZE];
32 	u8 key[DES3_KEY_SIZE];
33 };
34 
35 static int des_setkey(struct crypto_tfm *tfm, const u8 *key,
36 		      unsigned int key_len)
37 {
38 	struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
39 	int err;
40 
41 	err = crypto_des_verify_key(tfm, key);
42 	if (err)
43 		return err;
44 
45 	memcpy(ctx->key, key, key_len);
46 	return 0;
47 }
48 
49 static int des_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
50 			       unsigned int key_len)
51 {
52 	return des_setkey(crypto_skcipher_tfm(tfm), key, key_len);
53 }
54 
55 static void s390_des_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
56 {
57 	struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
58 
59 	cpacf_km(CPACF_KM_DEA, ctx->key, out, in, DES_BLOCK_SIZE);
60 }
61 
62 static void s390_des_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
63 {
64 	struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
65 
66 	cpacf_km(CPACF_KM_DEA | CPACF_DECRYPT,
67 		 ctx->key, out, in, DES_BLOCK_SIZE);
68 }
69 
70 static struct crypto_alg des_alg = {
71 	.cra_name		=	"des",
72 	.cra_driver_name	=	"des-s390",
73 	.cra_priority		=	300,
74 	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
75 	.cra_blocksize		=	DES_BLOCK_SIZE,
76 	.cra_ctxsize		=	sizeof(struct s390_des_ctx),
77 	.cra_module		=	THIS_MODULE,
78 	.cra_u			=	{
79 		.cipher = {
80 			.cia_min_keysize	=	DES_KEY_SIZE,
81 			.cia_max_keysize	=	DES_KEY_SIZE,
82 			.cia_setkey		=	des_setkey,
83 			.cia_encrypt		=	s390_des_encrypt,
84 			.cia_decrypt		=	s390_des_decrypt,
85 		}
86 	}
87 };
88 
89 static int ecb_desall_crypt(struct skcipher_request *req, unsigned long fc)
90 {
91 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
92 	struct s390_des_ctx *ctx = crypto_skcipher_ctx(tfm);
93 	struct skcipher_walk walk;
94 	unsigned int nbytes, n;
95 	int ret;
96 
97 	ret = skcipher_walk_virt(&walk, req, false);
98 	while ((nbytes = walk.nbytes) != 0) {
99 		/* only use complete blocks */
100 		n = nbytes & ~(DES_BLOCK_SIZE - 1);
101 		cpacf_km(fc, ctx->key, walk.dst.virt.addr,
102 			 walk.src.virt.addr, n);
103 		ret = skcipher_walk_done(&walk, nbytes - n);
104 	}
105 	return ret;
106 }
107 
108 static int cbc_desall_crypt(struct skcipher_request *req, unsigned long fc)
109 {
110 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
111 	struct s390_des_ctx *ctx = crypto_skcipher_ctx(tfm);
112 	struct skcipher_walk walk;
113 	unsigned int nbytes, n;
114 	int ret;
115 	struct {
116 		u8 iv[DES_BLOCK_SIZE];
117 		u8 key[DES3_KEY_SIZE];
118 	} param;
119 
120 	ret = skcipher_walk_virt(&walk, req, false);
121 	if (ret)
122 		return ret;
123 	memcpy(param.iv, walk.iv, DES_BLOCK_SIZE);
124 	memcpy(param.key, ctx->key, DES3_KEY_SIZE);
125 	while ((nbytes = walk.nbytes) != 0) {
126 		/* only use complete blocks */
127 		n = nbytes & ~(DES_BLOCK_SIZE - 1);
128 		cpacf_kmc(fc, &param, walk.dst.virt.addr,
129 			  walk.src.virt.addr, n);
130 		memcpy(walk.iv, param.iv, DES_BLOCK_SIZE);
131 		ret = skcipher_walk_done(&walk, nbytes - n);
132 	}
133 	return ret;
134 }
135 
136 static int ecb_des_encrypt(struct skcipher_request *req)
137 {
138 	return ecb_desall_crypt(req, CPACF_KM_DEA);
139 }
140 
141 static int ecb_des_decrypt(struct skcipher_request *req)
142 {
143 	return ecb_desall_crypt(req, CPACF_KM_DEA | CPACF_DECRYPT);
144 }
145 
146 static struct skcipher_alg ecb_des_alg = {
147 	.base.cra_name		=	"ecb(des)",
148 	.base.cra_driver_name	=	"ecb-des-s390",
149 	.base.cra_priority	=	400,	/* combo: des + ecb */
150 	.base.cra_blocksize	=	DES_BLOCK_SIZE,
151 	.base.cra_ctxsize	=	sizeof(struct s390_des_ctx),
152 	.base.cra_module	=	THIS_MODULE,
153 	.min_keysize		=	DES_KEY_SIZE,
154 	.max_keysize		=	DES_KEY_SIZE,
155 	.setkey			=	des_setkey_skcipher,
156 	.encrypt		=	ecb_des_encrypt,
157 	.decrypt		=	ecb_des_decrypt,
158 };
159 
160 static int cbc_des_encrypt(struct skcipher_request *req)
161 {
162 	return cbc_desall_crypt(req, CPACF_KMC_DEA);
163 }
164 
165 static int cbc_des_decrypt(struct skcipher_request *req)
166 {
167 	return cbc_desall_crypt(req, CPACF_KMC_DEA | CPACF_DECRYPT);
168 }
169 
170 static struct skcipher_alg cbc_des_alg = {
171 	.base.cra_name		=	"cbc(des)",
172 	.base.cra_driver_name	=	"cbc-des-s390",
173 	.base.cra_priority	=	400,	/* combo: des + cbc */
174 	.base.cra_blocksize	=	DES_BLOCK_SIZE,
175 	.base.cra_ctxsize	=	sizeof(struct s390_des_ctx),
176 	.base.cra_module	=	THIS_MODULE,
177 	.min_keysize		=	DES_KEY_SIZE,
178 	.max_keysize		=	DES_KEY_SIZE,
179 	.ivsize			=	DES_BLOCK_SIZE,
180 	.setkey			=	des_setkey_skcipher,
181 	.encrypt		=	cbc_des_encrypt,
182 	.decrypt		=	cbc_des_decrypt,
183 };
184 
185 /*
186  * RFC2451:
187  *
188  *   For DES-EDE3, there is no known need to reject weak or
189  *   complementation keys.  Any weakness is obviated by the use of
190  *   multiple keys.
191  *
192  *   However, if the first two or last two independent 64-bit keys are
193  *   equal (k1 == k2 or k2 == k3), then the DES3 operation is simply the
194  *   same as DES.  Implementers MUST reject keys that exhibit this
195  *   property.
196  *
197  *   In fips mode additionally check for all 3 keys are unique.
198  *
199  */
200 static int des3_setkey(struct crypto_tfm *tfm, const u8 *key,
201 		       unsigned int key_len)
202 {
203 	struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
204 	int err;
205 
206 	err = crypto_des3_ede_verify_key(tfm, key);
207 	if (err)
208 		return err;
209 
210 	memcpy(ctx->key, key, key_len);
211 	return 0;
212 }
213 
214 static int des3_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
215 				unsigned int key_len)
216 {
217 	return des3_setkey(crypto_skcipher_tfm(tfm), key, key_len);
218 }
219 
220 static void des3_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
221 {
222 	struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
223 
224 	cpacf_km(CPACF_KM_TDEA_192, ctx->key, dst, src, DES_BLOCK_SIZE);
225 }
226 
227 static void des3_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
228 {
229 	struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
230 
231 	cpacf_km(CPACF_KM_TDEA_192 | CPACF_DECRYPT,
232 		 ctx->key, dst, src, DES_BLOCK_SIZE);
233 }
234 
235 static struct crypto_alg des3_alg = {
236 	.cra_name		=	"des3_ede",
237 	.cra_driver_name	=	"des3_ede-s390",
238 	.cra_priority		=	300,
239 	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
240 	.cra_blocksize		=	DES_BLOCK_SIZE,
241 	.cra_ctxsize		=	sizeof(struct s390_des_ctx),
242 	.cra_module		=	THIS_MODULE,
243 	.cra_u			=	{
244 		.cipher = {
245 			.cia_min_keysize	=	DES3_KEY_SIZE,
246 			.cia_max_keysize	=	DES3_KEY_SIZE,
247 			.cia_setkey		=	des3_setkey,
248 			.cia_encrypt		=	des3_encrypt,
249 			.cia_decrypt		=	des3_decrypt,
250 		}
251 	}
252 };
253 
254 static int ecb_des3_encrypt(struct skcipher_request *req)
255 {
256 	return ecb_desall_crypt(req, CPACF_KM_TDEA_192);
257 }
258 
259 static int ecb_des3_decrypt(struct skcipher_request *req)
260 {
261 	return ecb_desall_crypt(req, CPACF_KM_TDEA_192 | CPACF_DECRYPT);
262 }
263 
264 static struct skcipher_alg ecb_des3_alg = {
265 	.base.cra_name		=	"ecb(des3_ede)",
266 	.base.cra_driver_name	=	"ecb-des3_ede-s390",
267 	.base.cra_priority	=	400,	/* combo: des3 + ecb */
268 	.base.cra_blocksize	=	DES_BLOCK_SIZE,
269 	.base.cra_ctxsize	=	sizeof(struct s390_des_ctx),
270 	.base.cra_module	=	THIS_MODULE,
271 	.min_keysize		=	DES3_KEY_SIZE,
272 	.max_keysize		=	DES3_KEY_SIZE,
273 	.setkey			=	des3_setkey_skcipher,
274 	.encrypt		=	ecb_des3_encrypt,
275 	.decrypt		=	ecb_des3_decrypt,
276 };
277 
278 static int cbc_des3_encrypt(struct skcipher_request *req)
279 {
280 	return cbc_desall_crypt(req, CPACF_KMC_TDEA_192);
281 }
282 
283 static int cbc_des3_decrypt(struct skcipher_request *req)
284 {
285 	return cbc_desall_crypt(req, CPACF_KMC_TDEA_192 | CPACF_DECRYPT);
286 }
287 
288 static struct skcipher_alg cbc_des3_alg = {
289 	.base.cra_name		=	"cbc(des3_ede)",
290 	.base.cra_driver_name	=	"cbc-des3_ede-s390",
291 	.base.cra_priority	=	400,	/* combo: des3 + cbc */
292 	.base.cra_blocksize	=	DES_BLOCK_SIZE,
293 	.base.cra_ctxsize	=	sizeof(struct s390_des_ctx),
294 	.base.cra_module	=	THIS_MODULE,
295 	.min_keysize		=	DES3_KEY_SIZE,
296 	.max_keysize		=	DES3_KEY_SIZE,
297 	.ivsize			=	DES_BLOCK_SIZE,
298 	.setkey			=	des3_setkey_skcipher,
299 	.encrypt		=	cbc_des3_encrypt,
300 	.decrypt		=	cbc_des3_decrypt,
301 };
302 
303 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
304 {
305 	unsigned int i, n;
306 
307 	/* align to block size, max. PAGE_SIZE */
308 	n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(DES_BLOCK_SIZE - 1);
309 	memcpy(ctrptr, iv, DES_BLOCK_SIZE);
310 	for (i = (n / DES_BLOCK_SIZE) - 1; i > 0; i--) {
311 		memcpy(ctrptr + DES_BLOCK_SIZE, ctrptr, DES_BLOCK_SIZE);
312 		crypto_inc(ctrptr + DES_BLOCK_SIZE, DES_BLOCK_SIZE);
313 		ctrptr += DES_BLOCK_SIZE;
314 	}
315 	return n;
316 }
317 
318 static int ctr_desall_crypt(struct skcipher_request *req, unsigned long fc)
319 {
320 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
321 	struct s390_des_ctx *ctx = crypto_skcipher_ctx(tfm);
322 	u8 buf[DES_BLOCK_SIZE], *ctrptr;
323 	struct skcipher_walk walk;
324 	unsigned int n, nbytes;
325 	int ret, locked;
326 
327 	locked = mutex_trylock(&ctrblk_lock);
328 
329 	ret = skcipher_walk_virt(&walk, req, false);
330 	while ((nbytes = walk.nbytes) >= DES_BLOCK_SIZE) {
331 		n = DES_BLOCK_SIZE;
332 		if (nbytes >= 2*DES_BLOCK_SIZE && locked)
333 			n = __ctrblk_init(ctrblk, walk.iv, nbytes);
334 		ctrptr = (n > DES_BLOCK_SIZE) ? ctrblk : walk.iv;
335 		cpacf_kmctr(fc, ctx->key, walk.dst.virt.addr,
336 			    walk.src.virt.addr, n, ctrptr);
337 		if (ctrptr == ctrblk)
338 			memcpy(walk.iv, ctrptr + n - DES_BLOCK_SIZE,
339 				DES_BLOCK_SIZE);
340 		crypto_inc(walk.iv, DES_BLOCK_SIZE);
341 		ret = skcipher_walk_done(&walk, nbytes - n);
342 	}
343 	if (locked)
344 		mutex_unlock(&ctrblk_lock);
345 	/* final block may be < DES_BLOCK_SIZE, copy only nbytes */
346 	if (nbytes) {
347 		cpacf_kmctr(fc, ctx->key, buf, walk.src.virt.addr,
348 			    DES_BLOCK_SIZE, walk.iv);
349 		memcpy(walk.dst.virt.addr, buf, nbytes);
350 		crypto_inc(walk.iv, DES_BLOCK_SIZE);
351 		ret = skcipher_walk_done(&walk, 0);
352 	}
353 	return ret;
354 }
355 
356 static int ctr_des_crypt(struct skcipher_request *req)
357 {
358 	return ctr_desall_crypt(req, CPACF_KMCTR_DEA);
359 }
360 
361 static struct skcipher_alg ctr_des_alg = {
362 	.base.cra_name		=	"ctr(des)",
363 	.base.cra_driver_name	=	"ctr-des-s390",
364 	.base.cra_priority	=	400,	/* combo: des + ctr */
365 	.base.cra_blocksize	=	1,
366 	.base.cra_ctxsize	=	sizeof(struct s390_des_ctx),
367 	.base.cra_module	=	THIS_MODULE,
368 	.min_keysize		=	DES_KEY_SIZE,
369 	.max_keysize		=	DES_KEY_SIZE,
370 	.ivsize			=	DES_BLOCK_SIZE,
371 	.setkey			=	des_setkey_skcipher,
372 	.encrypt		=	ctr_des_crypt,
373 	.decrypt		=	ctr_des_crypt,
374 	.chunksize		=	DES_BLOCK_SIZE,
375 };
376 
377 static int ctr_des3_crypt(struct skcipher_request *req)
378 {
379 	return ctr_desall_crypt(req, CPACF_KMCTR_TDEA_192);
380 }
381 
382 static struct skcipher_alg ctr_des3_alg = {
383 	.base.cra_name		=	"ctr(des3_ede)",
384 	.base.cra_driver_name	=	"ctr-des3_ede-s390",
385 	.base.cra_priority	=	400,	/* combo: des3 + ede */
386 	.base.cra_blocksize	=	1,
387 	.base.cra_ctxsize	=	sizeof(struct s390_des_ctx),
388 	.base.cra_module	=	THIS_MODULE,
389 	.min_keysize		=	DES3_KEY_SIZE,
390 	.max_keysize		=	DES3_KEY_SIZE,
391 	.ivsize			=	DES_BLOCK_SIZE,
392 	.setkey			=	des3_setkey_skcipher,
393 	.encrypt		=	ctr_des3_crypt,
394 	.decrypt		=	ctr_des3_crypt,
395 	.chunksize		=	DES_BLOCK_SIZE,
396 };
397 
398 static struct crypto_alg *des_s390_algs_ptr[2];
399 static int des_s390_algs_num;
400 static struct skcipher_alg *des_s390_skciphers_ptr[6];
401 static int des_s390_skciphers_num;
402 
403 static int des_s390_register_alg(struct crypto_alg *alg)
404 {
405 	int ret;
406 
407 	ret = crypto_register_alg(alg);
408 	if (!ret)
409 		des_s390_algs_ptr[des_s390_algs_num++] = alg;
410 	return ret;
411 }
412 
413 static int des_s390_register_skcipher(struct skcipher_alg *alg)
414 {
415 	int ret;
416 
417 	ret = crypto_register_skcipher(alg);
418 	if (!ret)
419 		des_s390_skciphers_ptr[des_s390_skciphers_num++] = alg;
420 	return ret;
421 }
422 
423 static void des_s390_exit(void)
424 {
425 	while (des_s390_algs_num--)
426 		crypto_unregister_alg(des_s390_algs_ptr[des_s390_algs_num]);
427 	while (des_s390_skciphers_num--)
428 		crypto_unregister_skcipher(des_s390_skciphers_ptr[des_s390_skciphers_num]);
429 	if (ctrblk)
430 		free_page((unsigned long) ctrblk);
431 }
432 
433 static int __init des_s390_init(void)
434 {
435 	int ret;
436 
437 	/* Query available functions for KM, KMC and KMCTR */
438 	cpacf_query(CPACF_KM, &km_functions);
439 	cpacf_query(CPACF_KMC, &kmc_functions);
440 	cpacf_query(CPACF_KMCTR, &kmctr_functions);
441 
442 	if (cpacf_test_func(&km_functions, CPACF_KM_DEA)) {
443 		ret = des_s390_register_alg(&des_alg);
444 		if (ret)
445 			goto out_err;
446 		ret = des_s390_register_skcipher(&ecb_des_alg);
447 		if (ret)
448 			goto out_err;
449 	}
450 	if (cpacf_test_func(&kmc_functions, CPACF_KMC_DEA)) {
451 		ret = des_s390_register_skcipher(&cbc_des_alg);
452 		if (ret)
453 			goto out_err;
454 	}
455 	if (cpacf_test_func(&km_functions, CPACF_KM_TDEA_192)) {
456 		ret = des_s390_register_alg(&des3_alg);
457 		if (ret)
458 			goto out_err;
459 		ret = des_s390_register_skcipher(&ecb_des3_alg);
460 		if (ret)
461 			goto out_err;
462 	}
463 	if (cpacf_test_func(&kmc_functions, CPACF_KMC_TDEA_192)) {
464 		ret = des_s390_register_skcipher(&cbc_des3_alg);
465 		if (ret)
466 			goto out_err;
467 	}
468 
469 	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_DEA) ||
470 	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_TDEA_192)) {
471 		ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
472 		if (!ctrblk) {
473 			ret = -ENOMEM;
474 			goto out_err;
475 		}
476 	}
477 
478 	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_DEA)) {
479 		ret = des_s390_register_skcipher(&ctr_des_alg);
480 		if (ret)
481 			goto out_err;
482 	}
483 	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_TDEA_192)) {
484 		ret = des_s390_register_skcipher(&ctr_des3_alg);
485 		if (ret)
486 			goto out_err;
487 	}
488 
489 	return 0;
490 out_err:
491 	des_s390_exit();
492 	return ret;
493 }
494 
495 module_cpu_feature_match(S390_CPU_FEATURE_MSA, des_s390_init);
496 module_exit(des_s390_exit);
497 
498 MODULE_ALIAS_CRYPTO("des");
499 MODULE_ALIAS_CRYPTO("des3_ede");
500 
501 MODULE_LICENSE("GPL");
502 MODULE_DESCRIPTION("DES & Triple DES EDE Cipher Algorithms");
503