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
25static u8 *ctrblk;
26static DEFINE_MUTEX(ctrblk_lock);
27
28static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
29
30struct s390_des_ctx {
31 u8 iv[DES_BLOCK_SIZE];
32 u8 key[DES3_KEY_SIZE];
33};
34
35static 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
49static int des_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
50 unsigned int key_len)
51{
52 return des_setkey(tfm: crypto_skcipher_tfm(tfm), key, key_len);
53}
54
55static 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
62static 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
70static 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
89static 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: &walk, req, atomic: 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: &walk, err: nbytes - n);
104 }
105 return ret;
106}
107
108static 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: &walk, req, atomic: 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: &walk, err: nbytes - n);
132 }
133 return ret;
134}
135
136static int ecb_des_encrypt(struct skcipher_request *req)
137{
138 return ecb_desall_crypt(req, fc: CPACF_KM_DEA);
139}
140
141static int ecb_des_decrypt(struct skcipher_request *req)
142{
143 return ecb_desall_crypt(req, fc: CPACF_KM_DEA | CPACF_DECRYPT);
144}
145
146static 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
160static int cbc_des_encrypt(struct skcipher_request *req)
161{
162 return cbc_desall_crypt(req, fc: CPACF_KMC_DEA);
163}
164
165static int cbc_des_decrypt(struct skcipher_request *req)
166{
167 return cbc_desall_crypt(req, fc: CPACF_KMC_DEA | CPACF_DECRYPT);
168}
169
170static 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 */
200static 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
214static int des3_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
215 unsigned int key_len)
216{
217 return des3_setkey(tfm: crypto_skcipher_tfm(tfm), key, key_len);
218}
219
220static 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
227static 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
235static 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
254static int ecb_des3_encrypt(struct skcipher_request *req)
255{
256 return ecb_desall_crypt(req, fc: CPACF_KM_TDEA_192);
257}
258
259static int ecb_des3_decrypt(struct skcipher_request *req)
260{
261 return ecb_desall_crypt(req, fc: CPACF_KM_TDEA_192 | CPACF_DECRYPT);
262}
263
264static 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
278static int cbc_des3_encrypt(struct skcipher_request *req)
279{
280 return cbc_desall_crypt(req, fc: CPACF_KMC_TDEA_192);
281}
282
283static int cbc_des3_decrypt(struct skcipher_request *req)
284{
285 return cbc_desall_crypt(req, fc: CPACF_KMC_TDEA_192 | CPACF_DECRYPT);
286}
287
288static 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
303static 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(a: ctrptr + DES_BLOCK_SIZE, DES_BLOCK_SIZE);
313 ctrptr += DES_BLOCK_SIZE;
314 }
315 return n;
316}
317
318static 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(lock: &ctrblk_lock);
328
329 ret = skcipher_walk_virt(walk: &walk, req, atomic: 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(ctrptr: ctrblk, iv: 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(a: walk.iv, DES_BLOCK_SIZE);
341 ret = skcipher_walk_done(walk: &walk, err: nbytes - n);
342 }
343 if (locked)
344 mutex_unlock(lock: &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(a: walk.iv, DES_BLOCK_SIZE);
351 ret = skcipher_walk_done(walk: &walk, err: 0);
352 }
353 return ret;
354}
355
356static int ctr_des_crypt(struct skcipher_request *req)
357{
358 return ctr_desall_crypt(req, fc: CPACF_KMCTR_DEA);
359}
360
361static 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
377static int ctr_des3_crypt(struct skcipher_request *req)
378{
379 return ctr_desall_crypt(req, fc: CPACF_KMCTR_TDEA_192);
380}
381
382static 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
398static struct crypto_alg *des_s390_algs_ptr[2];
399static int des_s390_algs_num;
400static struct skcipher_alg *des_s390_skciphers_ptr[6];
401static int des_s390_skciphers_num;
402
403static 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
413static 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
423static void des_s390_exit(void)
424{
425 while (des_s390_algs_num--)
426 crypto_unregister_alg(alg: des_s390_algs_ptr[des_s390_algs_num]);
427 while (des_s390_skciphers_num--)
428 crypto_unregister_skcipher(alg: des_s390_skciphers_ptr[des_s390_skciphers_num]);
429 if (ctrblk)
430 free_page((unsigned long) ctrblk);
431}
432
433static 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(alg: &des_alg);
444 if (ret)
445 goto out_err;
446 ret = des_s390_register_skcipher(alg: &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(alg: &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(alg: &des3_alg);
457 if (ret)
458 goto out_err;
459 ret = des_s390_register_skcipher(alg: &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(alg: &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(alg: &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(alg: &ctr_des3_alg);
485 if (ret)
486 goto out_err;
487 }
488
489 return 0;
490out_err:
491 des_s390_exit();
492 return ret;
493}
494
495module_cpu_feature_match(S390_CPU_FEATURE_MSA, des_s390_init);
496module_exit(des_s390_exit);
497
498MODULE_ALIAS_CRYPTO("des");
499MODULE_ALIAS_CRYPTO("des3_ede");
500
501MODULE_LICENSE("GPL");
502MODULE_DESCRIPTION("DES & Triple DES EDE Cipher Algorithms");
503

source code of linux/arch/s390/crypto/des_s390.c