1// SPDX-License-Identifier: GPL-2.0
2/*
3 * StarFive Public Key Algo acceleration driver
4 *
5 * Copyright (c) 2022 StarFive Technology
6 */
7
8#include <linux/crypto.h>
9#include <linux/iopoll.h>
10#include <crypto/akcipher.h>
11#include <crypto/algapi.h>
12#include <crypto/internal/akcipher.h>
13#include <crypto/internal/rsa.h>
14#include <crypto/scatterwalk.h>
15
16#include "jh7110-cryp.h"
17
18#define STARFIVE_PKA_REGS_OFFSET 0x400
19#define STARFIVE_PKA_CACR_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x0)
20#define STARFIVE_PKA_CASR_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x4)
21#define STARFIVE_PKA_CAAR_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x8)
22#define STARFIVE_PKA_CAER_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x108)
23#define STARFIVE_PKA_CANR_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x208)
24
25/* R ^ 2 mod N and N0' */
26#define CRYPTO_CMD_PRE 0x0
27/* A * R mod N ==> A */
28#define CRYPTO_CMD_ARN 0x5
29/* A * E * R mod N ==> A */
30#define CRYPTO_CMD_AERN 0x6
31/* A * A * R mod N ==> A */
32#define CRYPTO_CMD_AARN 0x7
33
34#define STARFIVE_RSA_MAX_KEYSZ 256
35#define STARFIVE_RSA_RESET 0x2
36
37static inline int starfive_pka_wait_done(struct starfive_cryp_ctx *ctx)
38{
39 struct starfive_cryp_dev *cryp = ctx->cryp;
40 u32 status;
41
42 return readl_relaxed_poll_timeout(cryp->base + STARFIVE_PKA_CASR_OFFSET, status,
43 status & STARFIVE_PKA_DONE, 10, 100000);
44}
45
46static void starfive_rsa_free_key(struct starfive_rsa_key *key)
47{
48 kfree_sensitive(objp: key->d);
49 kfree_sensitive(objp: key->e);
50 kfree_sensitive(objp: key->n);
51 memset(key, 0, sizeof(*key));
52}
53
54static unsigned int starfive_rsa_get_nbit(u8 *pa, u32 snum, int key_sz)
55{
56 u32 i;
57 u8 value;
58
59 i = snum >> 3;
60
61 value = pa[key_sz - i - 1];
62 value >>= snum & 0x7;
63 value &= 0x1;
64
65 return value;
66}
67
68static int starfive_rsa_montgomery_form(struct starfive_cryp_ctx *ctx,
69 u32 *out, u32 *in, u8 mont,
70 u32 *mod, int bit_len)
71{
72 struct starfive_cryp_dev *cryp = ctx->cryp;
73 struct starfive_cryp_request_ctx *rctx = ctx->rctx;
74 int count = rctx->total / sizeof(u32) - 1;
75 int loop;
76 u32 temp;
77 u8 opsize;
78
79 opsize = (bit_len - 1) >> 5;
80 rctx->csr.pka.v = 0;
81
82 writel(val: rctx->csr.pka.v, addr: cryp->base + STARFIVE_PKA_CACR_OFFSET);
83
84 for (loop = 0; loop <= opsize; loop++)
85 writel(val: mod[opsize - loop], addr: cryp->base + STARFIVE_PKA_CANR_OFFSET + loop * 4);
86
87 if (mont) {
88 rctx->csr.pka.v = 0;
89 rctx->csr.pka.cln_done = 1;
90 rctx->csr.pka.opsize = opsize;
91 rctx->csr.pka.exposize = opsize;
92 rctx->csr.pka.cmd = CRYPTO_CMD_PRE;
93 rctx->csr.pka.start = 1;
94 rctx->csr.pka.not_r2 = 1;
95 rctx->csr.pka.ie = 1;
96
97 writel(val: rctx->csr.pka.v, addr: cryp->base + STARFIVE_PKA_CACR_OFFSET);
98
99 if (starfive_pka_wait_done(ctx))
100 return -ETIMEDOUT;
101
102 for (loop = 0; loop <= opsize; loop++)
103 writel(val: in[opsize - loop], addr: cryp->base + STARFIVE_PKA_CAAR_OFFSET + loop * 4);
104
105 writel(val: 0x1000000, addr: cryp->base + STARFIVE_PKA_CAER_OFFSET);
106
107 for (loop = 1; loop <= opsize; loop++)
108 writel(val: 0, addr: cryp->base + STARFIVE_PKA_CAER_OFFSET + loop * 4);
109
110 rctx->csr.pka.v = 0;
111 rctx->csr.pka.cln_done = 1;
112 rctx->csr.pka.opsize = opsize;
113 rctx->csr.pka.exposize = opsize;
114 rctx->csr.pka.cmd = CRYPTO_CMD_AERN;
115 rctx->csr.pka.start = 1;
116 rctx->csr.pka.ie = 1;
117
118 writel(val: rctx->csr.pka.v, addr: cryp->base + STARFIVE_PKA_CACR_OFFSET);
119
120 if (starfive_pka_wait_done(ctx))
121 return -ETIMEDOUT;
122 } else {
123 rctx->csr.pka.v = 0;
124 rctx->csr.pka.cln_done = 1;
125 rctx->csr.pka.opsize = opsize;
126 rctx->csr.pka.exposize = opsize;
127 rctx->csr.pka.cmd = CRYPTO_CMD_PRE;
128 rctx->csr.pka.start = 1;
129 rctx->csr.pka.pre_expf = 1;
130 rctx->csr.pka.ie = 1;
131
132 writel(val: rctx->csr.pka.v, addr: cryp->base + STARFIVE_PKA_CACR_OFFSET);
133
134 if (starfive_pka_wait_done(ctx))
135 return -ETIMEDOUT;
136
137 for (loop = 0; loop <= count; loop++)
138 writel(val: in[count - loop], addr: cryp->base + STARFIVE_PKA_CAER_OFFSET + loop * 4);
139
140 /*pad with 0 up to opsize*/
141 for (loop = count + 1; loop <= opsize; loop++)
142 writel(val: 0, addr: cryp->base + STARFIVE_PKA_CAER_OFFSET + loop * 4);
143
144 rctx->csr.pka.v = 0;
145 rctx->csr.pka.cln_done = 1;
146 rctx->csr.pka.opsize = opsize;
147 rctx->csr.pka.exposize = opsize;
148 rctx->csr.pka.cmd = CRYPTO_CMD_ARN;
149 rctx->csr.pka.start = 1;
150 rctx->csr.pka.ie = 1;
151
152 writel(val: rctx->csr.pka.v, addr: cryp->base + STARFIVE_PKA_CACR_OFFSET);
153
154 if (starfive_pka_wait_done(ctx))
155 return -ETIMEDOUT;
156 }
157
158 for (loop = 0; loop <= opsize; loop++) {
159 temp = readl(addr: cryp->base + STARFIVE_PKA_CAAR_OFFSET + 0x4 * loop);
160 out[opsize - loop] = temp;
161 }
162
163 return 0;
164}
165
166static int starfive_rsa_cpu_start(struct starfive_cryp_ctx *ctx, u32 *result,
167 u8 *de, u32 *n, int key_sz)
168{
169 struct starfive_cryp_dev *cryp = ctx->cryp;
170 struct starfive_cryp_request_ctx *rctx = ctx->rctx;
171 struct starfive_rsa_key *key = &ctx->rsa_key;
172 u32 temp;
173 int ret = 0;
174 int opsize, mlen, loop;
175 unsigned int *mta;
176
177 opsize = (key_sz - 1) >> 2;
178
179 mta = kmalloc(size: key_sz, GFP_KERNEL);
180 if (!mta)
181 return -ENOMEM;
182
183 ret = starfive_rsa_montgomery_form(ctx, out: mta, in: (u32 *)rctx->rsa_data,
184 mont: 0, mod: n, bit_len: key_sz << 3);
185 if (ret) {
186 dev_err_probe(dev: cryp->dev, err: ret, fmt: "Conversion to Montgomery failed");
187 goto rsa_err;
188 }
189
190 for (loop = 0; loop <= opsize; loop++)
191 writel(val: mta[opsize - loop],
192 addr: cryp->base + STARFIVE_PKA_CAER_OFFSET + loop * 4);
193
194 for (loop = key->bitlen - 1; loop > 0; loop--) {
195 mlen = starfive_rsa_get_nbit(pa: de, snum: loop - 1, key_sz);
196
197 rctx->csr.pka.v = 0;
198 rctx->csr.pka.cln_done = 1;
199 rctx->csr.pka.opsize = opsize;
200 rctx->csr.pka.exposize = opsize;
201 rctx->csr.pka.cmd = CRYPTO_CMD_AARN;
202 rctx->csr.pka.start = 1;
203 rctx->csr.pka.ie = 1;
204
205 writel(val: rctx->csr.pka.v, addr: cryp->base + STARFIVE_PKA_CACR_OFFSET);
206
207 ret = -ETIMEDOUT;
208 if (starfive_pka_wait_done(ctx))
209 goto rsa_err;
210
211 if (mlen) {
212 rctx->csr.pka.v = 0;
213 rctx->csr.pka.cln_done = 1;
214 rctx->csr.pka.opsize = opsize;
215 rctx->csr.pka.exposize = opsize;
216 rctx->csr.pka.cmd = CRYPTO_CMD_AERN;
217 rctx->csr.pka.start = 1;
218 rctx->csr.pka.ie = 1;
219
220 writel(val: rctx->csr.pka.v, addr: cryp->base + STARFIVE_PKA_CACR_OFFSET);
221
222 if (starfive_pka_wait_done(ctx))
223 goto rsa_err;
224 }
225 }
226
227 for (loop = 0; loop <= opsize; loop++) {
228 temp = readl(addr: cryp->base + STARFIVE_PKA_CAAR_OFFSET + 0x4 * loop);
229 result[opsize - loop] = temp;
230 }
231
232 ret = starfive_rsa_montgomery_form(ctx, out: result, in: result, mont: 1, mod: n, bit_len: key_sz << 3);
233 if (ret)
234 dev_err_probe(dev: cryp->dev, err: ret, fmt: "Conversion from Montgomery failed");
235rsa_err:
236 kfree(objp: mta);
237 return ret;
238}
239
240static int starfive_rsa_start(struct starfive_cryp_ctx *ctx, u8 *result,
241 u8 *de, u8 *n, int key_sz)
242{
243 return starfive_rsa_cpu_start(ctx, result: (u32 *)result, de, n: (u32 *)n, key_sz);
244}
245
246static int starfive_rsa_enc_core(struct starfive_cryp_ctx *ctx, int enc)
247{
248 struct starfive_cryp_dev *cryp = ctx->cryp;
249 struct starfive_cryp_request_ctx *rctx = ctx->rctx;
250 struct starfive_rsa_key *key = &ctx->rsa_key;
251 int ret = 0;
252
253 writel(STARFIVE_RSA_RESET, addr: cryp->base + STARFIVE_PKA_CACR_OFFSET);
254
255 rctx->total = sg_copy_to_buffer(sgl: rctx->in_sg, nents: rctx->nents,
256 buf: rctx->rsa_data, buflen: rctx->total);
257
258 if (enc) {
259 key->bitlen = key->e_bitlen;
260 ret = starfive_rsa_start(ctx, result: rctx->rsa_data, de: key->e,
261 n: key->n, key_sz: key->key_sz);
262 } else {
263 key->bitlen = key->d_bitlen;
264 ret = starfive_rsa_start(ctx, result: rctx->rsa_data, de: key->d,
265 n: key->n, key_sz: key->key_sz);
266 }
267
268 if (ret)
269 goto err_rsa_crypt;
270
271 sg_copy_buffer(sgl: rctx->out_sg, nents: sg_nents(sg: rctx->out_sg),
272 buf: rctx->rsa_data, buflen: key->key_sz, skip: 0, to_buffer: 0);
273
274err_rsa_crypt:
275 writel(STARFIVE_RSA_RESET, addr: cryp->base + STARFIVE_PKA_CACR_OFFSET);
276 kfree(objp: rctx->rsa_data);
277 return ret;
278}
279
280static int starfive_rsa_enc(struct akcipher_request *req)
281{
282 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
283 struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
284 struct starfive_cryp_dev *cryp = ctx->cryp;
285 struct starfive_rsa_key *key = &ctx->rsa_key;
286 struct starfive_cryp_request_ctx *rctx = akcipher_request_ctx(req);
287 int ret;
288
289 if (!key->key_sz) {
290 akcipher_request_set_tfm(req, tfm: ctx->akcipher_fbk);
291 ret = crypto_akcipher_encrypt(req);
292 akcipher_request_set_tfm(req, tfm);
293 return ret;
294 }
295
296 if (unlikely(!key->n || !key->e))
297 return -EINVAL;
298
299 if (req->dst_len < key->key_sz)
300 return dev_err_probe(dev: cryp->dev, err: -EOVERFLOW,
301 fmt: "Output buffer length less than parameter n\n");
302
303 rctx->in_sg = req->src;
304 rctx->out_sg = req->dst;
305 rctx->total = req->src_len;
306 rctx->nents = sg_nents(sg: rctx->in_sg);
307 ctx->rctx = rctx;
308
309 return starfive_rsa_enc_core(ctx, enc: 1);
310}
311
312static int starfive_rsa_dec(struct akcipher_request *req)
313{
314 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
315 struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
316 struct starfive_cryp_dev *cryp = ctx->cryp;
317 struct starfive_rsa_key *key = &ctx->rsa_key;
318 struct starfive_cryp_request_ctx *rctx = akcipher_request_ctx(req);
319 int ret;
320
321 if (!key->key_sz) {
322 akcipher_request_set_tfm(req, tfm: ctx->akcipher_fbk);
323 ret = crypto_akcipher_decrypt(req);
324 akcipher_request_set_tfm(req, tfm);
325 return ret;
326 }
327
328 if (unlikely(!key->n || !key->d))
329 return -EINVAL;
330
331 if (req->dst_len < key->key_sz)
332 return dev_err_probe(dev: cryp->dev, err: -EOVERFLOW,
333 fmt: "Output buffer length less than parameter n\n");
334
335 rctx->in_sg = req->src;
336 rctx->out_sg = req->dst;
337 ctx->rctx = rctx;
338 rctx->total = req->src_len;
339
340 return starfive_rsa_enc_core(ctx, enc: 0);
341}
342
343static int starfive_rsa_set_n(struct starfive_rsa_key *rsa_key,
344 const char *value, size_t vlen)
345{
346 const char *ptr = value;
347 unsigned int bitslen;
348 int ret;
349
350 while (!*ptr && vlen) {
351 ptr++;
352 vlen--;
353 }
354 rsa_key->key_sz = vlen;
355 bitslen = rsa_key->key_sz << 3;
356
357 /* check valid key size */
358 if (bitslen & 0x1f)
359 return -EINVAL;
360
361 ret = -ENOMEM;
362 rsa_key->n = kmemdup(p: ptr, size: rsa_key->key_sz, GFP_KERNEL);
363 if (!rsa_key->n)
364 goto err;
365
366 return 0;
367 err:
368 rsa_key->key_sz = 0;
369 rsa_key->n = NULL;
370 starfive_rsa_free_key(key: rsa_key);
371 return ret;
372}
373
374static int starfive_rsa_set_e(struct starfive_rsa_key *rsa_key,
375 const char *value, size_t vlen)
376{
377 const char *ptr = value;
378 unsigned char pt;
379 int loop;
380
381 while (!*ptr && vlen) {
382 ptr++;
383 vlen--;
384 }
385 pt = *ptr;
386
387 if (!rsa_key->key_sz || !vlen || vlen > rsa_key->key_sz) {
388 rsa_key->e = NULL;
389 return -EINVAL;
390 }
391
392 rsa_key->e = kzalloc(size: rsa_key->key_sz, GFP_KERNEL);
393 if (!rsa_key->e)
394 return -ENOMEM;
395
396 for (loop = 8; loop > 0; loop--) {
397 if (pt >> (loop - 1))
398 break;
399 }
400
401 rsa_key->e_bitlen = (vlen - 1) * 8 + loop;
402
403 memcpy(rsa_key->e + (rsa_key->key_sz - vlen), ptr, vlen);
404
405 return 0;
406}
407
408static int starfive_rsa_set_d(struct starfive_rsa_key *rsa_key,
409 const char *value, size_t vlen)
410{
411 const char *ptr = value;
412 unsigned char pt;
413 int loop;
414 int ret;
415
416 while (!*ptr && vlen) {
417 ptr++;
418 vlen--;
419 }
420 pt = *ptr;
421
422 ret = -EINVAL;
423 if (!rsa_key->key_sz || !vlen || vlen > rsa_key->key_sz)
424 goto err;
425
426 ret = -ENOMEM;
427 rsa_key->d = kzalloc(size: rsa_key->key_sz, GFP_KERNEL);
428 if (!rsa_key->d)
429 goto err;
430
431 for (loop = 8; loop > 0; loop--) {
432 if (pt >> (loop - 1))
433 break;
434 }
435
436 rsa_key->d_bitlen = (vlen - 1) * 8 + loop;
437
438 memcpy(rsa_key->d + (rsa_key->key_sz - vlen), ptr, vlen);
439
440 return 0;
441 err:
442 rsa_key->d = NULL;
443 return ret;
444}
445
446static int starfive_rsa_setkey(struct crypto_akcipher *tfm, const void *key,
447 unsigned int keylen, bool private)
448{
449 struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
450 struct rsa_key raw_key = {NULL};
451 struct starfive_rsa_key *rsa_key = &ctx->rsa_key;
452 int ret;
453
454 if (private)
455 ret = rsa_parse_priv_key(rsa_key: &raw_key, key, key_len: keylen);
456 else
457 ret = rsa_parse_pub_key(rsa_key: &raw_key, key, key_len: keylen);
458 if (ret < 0)
459 goto err;
460
461 starfive_rsa_free_key(key: rsa_key);
462
463 /* Use fallback for mod > 256 + 1 byte prefix */
464 if (raw_key.n_sz > STARFIVE_RSA_MAX_KEYSZ + 1)
465 return 0;
466
467 ret = starfive_rsa_set_n(rsa_key, value: raw_key.n, vlen: raw_key.n_sz);
468 if (ret)
469 return ret;
470
471 ret = starfive_rsa_set_e(rsa_key, value: raw_key.e, vlen: raw_key.e_sz);
472 if (ret)
473 goto err;
474
475 if (private) {
476 ret = starfive_rsa_set_d(rsa_key, value: raw_key.d, vlen: raw_key.d_sz);
477 if (ret)
478 goto err;
479 }
480
481 if (!rsa_key->n || !rsa_key->e) {
482 ret = -EINVAL;
483 goto err;
484 }
485
486 if (private && !rsa_key->d) {
487 ret = -EINVAL;
488 goto err;
489 }
490
491 return 0;
492 err:
493 starfive_rsa_free_key(key: rsa_key);
494 return ret;
495}
496
497static int starfive_rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
498 unsigned int keylen)
499{
500 struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
501 int ret;
502
503 ret = crypto_akcipher_set_pub_key(tfm: ctx->akcipher_fbk, key, keylen);
504 if (ret)
505 return ret;
506
507 return starfive_rsa_setkey(tfm, key, keylen, private: false);
508}
509
510static int starfive_rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
511 unsigned int keylen)
512{
513 struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
514 int ret;
515
516 ret = crypto_akcipher_set_priv_key(tfm: ctx->akcipher_fbk, key, keylen);
517 if (ret)
518 return ret;
519
520 return starfive_rsa_setkey(tfm, key, keylen, private: true);
521}
522
523static unsigned int starfive_rsa_max_size(struct crypto_akcipher *tfm)
524{
525 struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
526
527 if (ctx->rsa_key.key_sz)
528 return ctx->rsa_key.key_sz;
529
530 return crypto_akcipher_maxsize(tfm: ctx->akcipher_fbk);
531}
532
533static int starfive_rsa_init_tfm(struct crypto_akcipher *tfm)
534{
535 struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
536
537 ctx->akcipher_fbk = crypto_alloc_akcipher(alg_name: "rsa-generic", type: 0, mask: 0);
538 if (IS_ERR(ptr: ctx->akcipher_fbk))
539 return PTR_ERR(ptr: ctx->akcipher_fbk);
540
541 ctx->cryp = starfive_cryp_find_dev(ctx);
542 if (!ctx->cryp) {
543 crypto_free_akcipher(tfm: ctx->akcipher_fbk);
544 return -ENODEV;
545 }
546
547 akcipher_set_reqsize(akcipher: tfm, reqsize: sizeof(struct starfive_cryp_request_ctx) +
548 sizeof(struct crypto_akcipher) + 32);
549
550 return 0;
551}
552
553static void starfive_rsa_exit_tfm(struct crypto_akcipher *tfm)
554{
555 struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
556 struct starfive_rsa_key *key = (struct starfive_rsa_key *)&ctx->rsa_key;
557
558 crypto_free_akcipher(tfm: ctx->akcipher_fbk);
559 starfive_rsa_free_key(key);
560}
561
562static struct akcipher_alg starfive_rsa = {
563 .encrypt = starfive_rsa_enc,
564 .decrypt = starfive_rsa_dec,
565 .sign = starfive_rsa_dec,
566 .verify = starfive_rsa_enc,
567 .set_pub_key = starfive_rsa_set_pub_key,
568 .set_priv_key = starfive_rsa_set_priv_key,
569 .max_size = starfive_rsa_max_size,
570 .init = starfive_rsa_init_tfm,
571 .exit = starfive_rsa_exit_tfm,
572 .base = {
573 .cra_name = "rsa",
574 .cra_driver_name = "starfive-rsa",
575 .cra_flags = CRYPTO_ALG_TYPE_AKCIPHER |
576 CRYPTO_ALG_NEED_FALLBACK,
577 .cra_priority = 3000,
578 .cra_module = THIS_MODULE,
579 .cra_ctxsize = sizeof(struct starfive_cryp_ctx),
580 },
581};
582
583int starfive_rsa_register_algs(void)
584{
585 return crypto_register_akcipher(alg: &starfive_rsa);
586}
587
588void starfive_rsa_unregister_algs(void)
589{
590 crypto_unregister_akcipher(alg: &starfive_rsa);
591}
592

source code of linux/drivers/crypto/starfive/jh7110-rsa.c