2 * RSA padding templates.
4 * Copyright (c) 2015 Intel Corporation
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
12 #include <crypto/algapi.h>
13 #include <crypto/akcipher.h>
14 #include <crypto/internal/akcipher.h>
15 #include <crypto/internal/rsa.h>
16 #include <linux/err.h>
17 #include <linux/init.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/random.h>
23 * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
25 static const u8 rsa_digest_info_md5[] = {
26 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
27 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
28 0x05, 0x00, 0x04, 0x10
31 static const u8 rsa_digest_info_sha1[] = {
32 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
33 0x2b, 0x0e, 0x03, 0x02, 0x1a,
34 0x05, 0x00, 0x04, 0x14
37 static const u8 rsa_digest_info_rmd160[] = {
38 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
39 0x2b, 0x24, 0x03, 0x02, 0x01,
40 0x05, 0x00, 0x04, 0x14
43 static const u8 rsa_digest_info_sha224[] = {
44 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
45 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
46 0x05, 0x00, 0x04, 0x1c
49 static const u8 rsa_digest_info_sha256[] = {
50 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
51 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
52 0x05, 0x00, 0x04, 0x20
55 static const u8 rsa_digest_info_sha384[] = {
56 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
57 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
58 0x05, 0x00, 0x04, 0x30
61 static const u8 rsa_digest_info_sha512[] = {
62 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
63 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
64 0x05, 0x00, 0x04, 0x40
67 static const struct rsa_asn1_template {
71 } rsa_asn1_templates[] = {
72 #define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
84 static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
86 const struct rsa_asn1_template *p;
88 for (p = rsa_asn1_templates; p->name; p++)
89 if (strcmp(name, p->name) == 0)
95 struct crypto_akcipher *child;
96 unsigned int key_size;
99 struct pkcs1pad_inst_ctx {
100 struct crypto_akcipher_spawn spawn;
101 const struct rsa_asn1_template *digest_info;
104 struct pkcs1pad_request {
105 struct scatterlist in_sg[2], out_sg[1];
106 uint8_t *in_buf, *out_buf;
107 struct akcipher_request child_req;
110 static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
113 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
118 err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
122 /* Find out new modulus size from rsa implementation */
123 err = crypto_akcipher_maxsize(ctx->child);
131 static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
134 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
139 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
143 /* Find out new modulus size from rsa implementation */
144 err = crypto_akcipher_maxsize(ctx->child);
152 static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
154 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
157 * The maximum destination buffer size for the encrypt/sign operations
158 * will be the same as for RSA, even though it's smaller for
162 return ctx->key_size;
165 static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
166 struct scatterlist *next)
168 int nsegs = next ? 2 : 1;
170 sg_init_table(sg, nsegs);
171 sg_set_buf(sg, buf, len);
174 sg_chain(sg, nsegs, next);
177 static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
179 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
180 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
181 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
182 unsigned int pad_len;
189 len = req_ctx->child_req.dst_len;
190 pad_len = ctx->key_size - len;
192 /* Four billion to one */
193 if (likely(!pad_len))
196 out_buf = kzalloc(ctx->key_size, GFP_KERNEL);
201 sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len),
202 out_buf + pad_len, len);
203 sg_copy_from_buffer(req->dst,
204 sg_nents_for_len(req->dst, ctx->key_size),
205 out_buf, ctx->key_size);
209 req->dst_len = ctx->key_size;
211 kfree(req_ctx->in_buf);
216 static void pkcs1pad_encrypt_sign_complete_cb(
217 struct crypto_async_request *child_async_req, int err)
219 struct akcipher_request *req = child_async_req->data;
220 struct crypto_async_request async_req;
222 if (err == -EINPROGRESS)
225 async_req.data = req->base.data;
226 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
227 async_req.flags = child_async_req->flags;
228 req->base.complete(&async_req,
229 pkcs1pad_encrypt_sign_complete(req, err));
232 static int pkcs1pad_encrypt(struct akcipher_request *req)
234 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
235 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
236 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
238 unsigned int i, ps_end;
243 if (req->src_len > ctx->key_size - 11)
246 if (req->dst_len < ctx->key_size) {
247 req->dst_len = ctx->key_size;
251 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
253 if (!req_ctx->in_buf)
256 ps_end = ctx->key_size - req->src_len - 2;
257 req_ctx->in_buf[0] = 0x02;
258 for (i = 1; i < ps_end; i++)
259 req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
260 req_ctx->in_buf[ps_end] = 0x00;
262 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
263 ctx->key_size - 1 - req->src_len, req->src);
265 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
266 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
267 pkcs1pad_encrypt_sign_complete_cb, req);
269 /* Reuse output buffer */
270 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
271 req->dst, ctx->key_size - 1, req->dst_len);
273 err = crypto_akcipher_encrypt(&req_ctx->child_req);
274 if (err != -EINPROGRESS && err != -EBUSY)
275 return pkcs1pad_encrypt_sign_complete(req, err);
280 static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
282 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
283 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
284 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
285 unsigned int dst_len;
293 dst_len = req_ctx->child_req.dst_len;
294 if (dst_len < ctx->key_size - 1)
297 out_buf = req_ctx->out_buf;
298 if (dst_len == ctx->key_size) {
299 if (out_buf[0] != 0x00)
300 /* Decrypted value had no leading 0 byte */
307 if (out_buf[0] != 0x02)
310 for (pos = 1; pos < dst_len; pos++)
311 if (out_buf[pos] == 0x00)
313 if (pos < 9 || pos == dst_len)
319 if (req->dst_len < dst_len - pos)
321 req->dst_len = dst_len - pos;
324 sg_copy_from_buffer(req->dst,
325 sg_nents_for_len(req->dst, req->dst_len),
326 out_buf + pos, req->dst_len);
329 kzfree(req_ctx->out_buf);
334 static void pkcs1pad_decrypt_complete_cb(
335 struct crypto_async_request *child_async_req, int err)
337 struct akcipher_request *req = child_async_req->data;
338 struct crypto_async_request async_req;
340 if (err == -EINPROGRESS)
343 async_req.data = req->base.data;
344 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
345 async_req.flags = child_async_req->flags;
346 req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
349 static int pkcs1pad_decrypt(struct akcipher_request *req)
351 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
352 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
353 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
356 if (!ctx->key_size || req->src_len != ctx->key_size)
359 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
360 if (!req_ctx->out_buf)
363 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
364 ctx->key_size, NULL);
366 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
367 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
368 pkcs1pad_decrypt_complete_cb, req);
370 /* Reuse input buffer, output to a new buffer */
371 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
372 req_ctx->out_sg, req->src_len,
375 err = crypto_akcipher_decrypt(&req_ctx->child_req);
376 if (err != -EINPROGRESS && err != -EBUSY)
377 return pkcs1pad_decrypt_complete(req, err);
382 static int pkcs1pad_sign(struct akcipher_request *req)
384 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
385 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
386 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
387 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
388 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
389 const struct rsa_asn1_template *digest_info = ictx->digest_info;
391 unsigned int ps_end, digest_size = 0;
397 digest_size = digest_info->size;
399 if (req->src_len + digest_size > ctx->key_size - 11)
402 if (req->dst_len < ctx->key_size) {
403 req->dst_len = ctx->key_size;
407 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
409 if (!req_ctx->in_buf)
412 ps_end = ctx->key_size - digest_size - req->src_len - 2;
413 req_ctx->in_buf[0] = 0x01;
414 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
415 req_ctx->in_buf[ps_end] = 0x00;
418 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
421 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
422 ctx->key_size - 1 - req->src_len, req->src);
424 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
425 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
426 pkcs1pad_encrypt_sign_complete_cb, req);
428 /* Reuse output buffer */
429 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
430 req->dst, ctx->key_size - 1, req->dst_len);
432 err = crypto_akcipher_sign(&req_ctx->child_req);
433 if (err != -EINPROGRESS && err != -EBUSY)
434 return pkcs1pad_encrypt_sign_complete(req, err);
439 static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
441 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
442 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
443 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
444 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
445 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
446 const struct rsa_asn1_template *digest_info = ictx->digest_info;
447 unsigned int dst_len;
455 dst_len = req_ctx->child_req.dst_len;
456 if (dst_len < ctx->key_size - 1)
459 out_buf = req_ctx->out_buf;
460 if (dst_len == ctx->key_size) {
461 if (out_buf[0] != 0x00)
462 /* Decrypted value had no leading 0 byte */
470 if (out_buf[0] != 0x01)
473 for (pos = 1; pos < dst_len; pos++)
474 if (out_buf[pos] != 0xff)
477 if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00)
482 if (crypto_memneq(out_buf + pos, digest_info->data,
486 pos += digest_info->size;
491 if (req->dst_len < dst_len - pos)
493 req->dst_len = dst_len - pos;
496 sg_copy_from_buffer(req->dst,
497 sg_nents_for_len(req->dst, req->dst_len),
498 out_buf + pos, req->dst_len);
500 kzfree(req_ctx->out_buf);
505 static void pkcs1pad_verify_complete_cb(
506 struct crypto_async_request *child_async_req, int err)
508 struct akcipher_request *req = child_async_req->data;
509 struct crypto_async_request async_req;
511 if (err == -EINPROGRESS)
514 async_req.data = req->base.data;
515 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
516 async_req.flags = child_async_req->flags;
517 req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
521 * The verify operation is here for completeness similar to the verification
522 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
523 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
524 * retrieve the DigestInfo from a signature, instead the user is expected
525 * to call the sign operation to generate the expected signature and compare
526 * signatures instead of the message-digests.
528 static int pkcs1pad_verify(struct akcipher_request *req)
530 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
531 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
532 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
535 if (!ctx->key_size || req->src_len < ctx->key_size)
538 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
539 if (!req_ctx->out_buf)
542 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
543 ctx->key_size, NULL);
545 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
546 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
547 pkcs1pad_verify_complete_cb, req);
549 /* Reuse input buffer, output to a new buffer */
550 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
551 req_ctx->out_sg, req->src_len,
554 err = crypto_akcipher_verify(&req_ctx->child_req);
555 if (err != -EINPROGRESS && err != -EBUSY)
556 return pkcs1pad_verify_complete(req, err);
561 static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
563 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
564 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
565 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
566 struct crypto_akcipher *child_tfm;
568 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
569 if (IS_ERR(child_tfm))
570 return PTR_ERR(child_tfm);
572 ctx->child = child_tfm;
576 static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
578 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
580 crypto_free_akcipher(ctx->child);
583 static void pkcs1pad_free(struct akcipher_instance *inst)
585 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
586 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
588 crypto_drop_akcipher(spawn);
592 static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
594 const struct rsa_asn1_template *digest_info;
595 struct crypto_attr_type *algt;
596 struct akcipher_instance *inst;
597 struct pkcs1pad_inst_ctx *ctx;
598 struct crypto_akcipher_spawn *spawn;
599 struct akcipher_alg *rsa_alg;
600 const char *rsa_alg_name;
601 const char *hash_name;
604 algt = crypto_get_attr_type(tb);
606 return PTR_ERR(algt);
608 if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
611 rsa_alg_name = crypto_attr_alg_name(tb[1]);
612 if (IS_ERR(rsa_alg_name))
613 return PTR_ERR(rsa_alg_name);
615 hash_name = crypto_attr_alg_name(tb[2]);
616 if (IS_ERR(hash_name))
620 digest_info = rsa_lookup_asn1(hash_name);
626 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
630 ctx = akcipher_instance_ctx(inst);
632 ctx->digest_info = digest_info;
634 crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
635 err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
636 crypto_requires_sync(algt->type, algt->mask));
640 rsa_alg = crypto_spawn_akcipher_alg(spawn);
645 if (snprintf(inst->alg.base.cra_name,
646 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
647 rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
650 if (snprintf(inst->alg.base.cra_driver_name,
651 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
652 rsa_alg->base.cra_driver_name) >=
656 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
657 "pkcs1pad(%s,%s)", rsa_alg->base.cra_name,
658 hash_name) >= CRYPTO_MAX_ALG_NAME)
661 if (snprintf(inst->alg.base.cra_driver_name,
662 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
663 rsa_alg->base.cra_driver_name,
664 hash_name) >= CRYPTO_MAX_ALG_NAME)
668 inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
669 inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
670 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
672 inst->alg.init = pkcs1pad_init_tfm;
673 inst->alg.exit = pkcs1pad_exit_tfm;
675 inst->alg.encrypt = pkcs1pad_encrypt;
676 inst->alg.decrypt = pkcs1pad_decrypt;
677 inst->alg.sign = pkcs1pad_sign;
678 inst->alg.verify = pkcs1pad_verify;
679 inst->alg.set_pub_key = pkcs1pad_set_pub_key;
680 inst->alg.set_priv_key = pkcs1pad_set_priv_key;
681 inst->alg.max_size = pkcs1pad_get_max_size;
682 inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;
684 inst->free = pkcs1pad_free;
686 err = akcipher_register_instance(tmpl, inst);
693 crypto_drop_akcipher(spawn);
699 struct crypto_template rsa_pkcs1pad_tmpl = {
701 .create = pkcs1pad_create,
702 .module = THIS_MODULE,