crypto/rsa-pkcs1pad.c

   1 /*
   2  * RSA padding templates.
   3  *
   4  * Copyright (c) 2015  Intel Corporation
   5  *
   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)
   9  * any later version.
  10  */
  11
  12 #include <crypto/algapi.h>
  13 #include <crypto/akcipher.h>
  14 #include <crypto/internal/akcipher.h>
  15 #include <linux/err.h>
  16 #include <linux/init.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/random.h>
  20
  21 /*
  22  * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
  23  */
  24 static const u8 rsa_digest_info_md5[] = {
  25         0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
  26         0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
  27         0x05, 0x00, 0x04, 0x10
  28 };
  29
  30 static const u8 rsa_digest_info_sha1[] = {
  31         0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
  32         0x2b, 0x0e, 0x03, 0x02, 0x1a,
  33         0x05, 0x00, 0x04, 0x14
  34 };
  35
  36 static const u8 rsa_digest_info_rmd160[] = {
  37         0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
  38         0x2b, 0x24, 0x03, 0x02, 0x01,
  39         0x05, 0x00, 0x04, 0x14
  40 };
  41
  42 static const u8 rsa_digest_info_sha224[] = {
  43         0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
  44         0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
  45         0x05, 0x00, 0x04, 0x1c
  46 };
  47
  48 static const u8 rsa_digest_info_sha256[] = {
  49         0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
  50         0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
  51         0x05, 0x00, 0x04, 0x20
  52 };
  53
  54 static const u8 rsa_digest_info_sha384[] = {
  55         0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
  56         0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
  57         0x05, 0x00, 0x04, 0x30
  58 };
  59
  60 static const u8 rsa_digest_info_sha512[] = {
  61         0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
  62         0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
  63         0x05, 0x00, 0x04, 0x40
  64 };
  65
  66 static const struct rsa_asn1_template {
  67         const char      *name;
  68         const u8        *data;
  69         size_t          size;
  70 } rsa_asn1_templates[] = {
  71 #define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
  72         _(md5),
  73         _(sha1),
  74         _(rmd160),
  75         _(sha256),
  76         _(sha384),
  77         _(sha512),
  78         _(sha224),
  79         { NULL }
  80 #undef _
  81 };
  82
  83 static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
  84 {
  85         const struct rsa_asn1_template *p;
  86
  87         for (p = rsa_asn1_templates; p->name; p++)
  88                 if (strcmp(name, p->name) == 0)
  89                         return p;
  90         return NULL;
  91 }
  92
  93 struct pkcs1pad_ctx {
  94         struct crypto_akcipher *child;
  95         const char *hash_name;
  96         unsigned int key_size;
  97 };
  98
  99 struct pkcs1pad_inst_ctx {
 100         struct crypto_akcipher_spawn spawn;
 101         const char *hash_name;
 102 };
 103
 104 struct pkcs1pad_request {
 105         struct akcipher_request child_req;
 106
 107         struct scatterlist in_sg[3], out_sg[2];
 108         uint8_t *in_buf, *out_buf;
 109 };
 110
 111 static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
 112                 unsigned int keylen)
 113 {
 114         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 115         int err, size;
 116
 117         err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
 118
 119         if (!err) {
 120                 /* Find out new modulus size from rsa implementation */
 121                 size = crypto_akcipher_maxsize(ctx->child);
 122
 123                 ctx->key_size = size > 0 ? size : 0;
 124                 if (size <= 0)
 125                         err = size;
 126         }
 127
 128         return err;
 129 }
 130
 131 static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
 132                 unsigned int keylen)
 133 {
 134         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 135         int err, size;
 136
 137         err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
 138
 139         if (!err) {
 140                 /* Find out new modulus size from rsa implementation */
 141                 size = crypto_akcipher_maxsize(ctx->child);
 142
 143                 ctx->key_size = size > 0 ? size : 0;
 144                 if (size <= 0)
 145                         err = size;
 146         }
 147
 148         return err;
 149 }
 150
 151 static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
 152 {
 153         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 154
 155         /*
 156          * The maximum destination buffer size for the encrypt/sign operations
 157          * will be the same as for RSA, even though it's smaller for
 158          * decrypt/verify.
 159          */
 160
 161         return ctx->key_size ?: -EINVAL;
 162 }
 163
 164 static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
 165                 struct scatterlist *next)
 166 {
 167         int nsegs = next ? 1 : 0;
 168
 169         if (offset_in_page(buf) + len <= PAGE_SIZE) {
 170                 nsegs += 1;
 171                 sg_init_table(sg, nsegs);
 172                 sg_set_buf(sg, buf, len);
 173         } else {
 174                 nsegs += 2;
 175                 sg_init_table(sg, nsegs);
 176                 sg_set_buf(sg + 0, buf, PAGE_SIZE - offset_in_page(buf));
 177                 sg_set_buf(sg + 1, buf + PAGE_SIZE - offset_in_page(buf),
 178                                 offset_in_page(buf) + len - PAGE_SIZE);
 179         }
 180
 181         if (next)
 182                 sg_chain(sg, nsegs, next);
 183 }
 184
 185 static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
 186 {
 187         struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 188         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 189         struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
 190         size_t pad_len = ctx->key_size - req_ctx->child_req.dst_len;
 191         size_t chunk_len, pad_left;
 192         struct sg_mapping_iter miter;
 193
 194         if (!err) {
 195                 if (pad_len) {
 196                         sg_miter_start(&miter, req->dst,
 197                                         sg_nents_for_len(req->dst, pad_len),
 198                                         SG_MITER_ATOMIC | SG_MITER_TO_SG);
 199
 200                         pad_left = pad_len;
 201                         while (pad_left) {
 202                                 sg_miter_next(&miter);
 203
 204                                 chunk_len = min(miter.length, pad_left);
 205                                 memset(miter.addr, 0, chunk_len);
 206                                 pad_left -= chunk_len;
 207                         }
 208
 209                         sg_miter_stop(&miter);
 210                 }
 211
 212                 sg_pcopy_from_buffer(req->dst,
 213                                 sg_nents_for_len(req->dst, ctx->key_size),
 214                                 req_ctx->out_buf, req_ctx->child_req.dst_len,
 215                                 pad_len);
 216         }
 217         req->dst_len = ctx->key_size;
 218
 219         kfree(req_ctx->in_buf);
 220         kzfree(req_ctx->out_buf);
 221
 222         return err;
 223 }
 224
 225 static void pkcs1pad_encrypt_sign_complete_cb(
 226                 struct crypto_async_request *child_async_req, int err)
 227 {
 228         struct akcipher_request *req = child_async_req->data;
 229         struct crypto_async_request async_req;
 230
 231         if (err == -EINPROGRESS)
 232                 return;
 233
 234         async_req.data = req->base.data;
 235         async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
 236         async_req.flags = child_async_req->flags;
 237         req->base.complete(&async_req,
 238                         pkcs1pad_encrypt_sign_complete(req, err));
 239 }
 240
 241 static int pkcs1pad_encrypt(struct akcipher_request *req)
 242 {
 243         struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 244         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 245         struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
 246         int err;
 247         unsigned int i, ps_end;
 248
 249         if (!ctx->key_size)
 250                 return -EINVAL;
 251
 252         if (req->src_len > ctx->key_size - 11)
 253                 return -EOVERFLOW;
 254
 255         if (req->dst_len < ctx->key_size) {
 256                 req->dst_len = ctx->key_size;
 257                 return -EOVERFLOW;
 258         }
 259
 260         if (ctx->key_size > PAGE_SIZE)
 261                 return -ENOTSUPP;
 262
 263         /*
 264          * Replace both input and output to add the padding in the input and
 265          * the potential missing leading zeros in the output.
 266          */
 267         req_ctx->child_req.src = req_ctx->in_sg;
 268         req_ctx->child_req.src_len = ctx->key_size - 1;
 269         req_ctx->child_req.dst = req_ctx->out_sg;
 270         req_ctx->child_req.dst_len = ctx->key_size;
 271
 272         req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
 273                         (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 274                         GFP_KERNEL : GFP_ATOMIC);
 275         if (!req_ctx->in_buf)
 276                 return -ENOMEM;
 277
 278         ps_end = ctx->key_size - req->src_len - 2;
 279         req_ctx->in_buf[0] = 0x02;
 280         for (i = 1; i < ps_end; i++)
 281                 req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
 282         req_ctx->in_buf[ps_end] = 0x00;
 283
 284         pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
 285                         ctx->key_size - 1 - req->src_len, req->src);
 286
 287         req_ctx->out_buf = kmalloc(ctx->key_size,
 288                         (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 289                         GFP_KERNEL : GFP_ATOMIC);
 290         if (!req_ctx->out_buf) {
 291                 kfree(req_ctx->in_buf);
 292                 return -ENOMEM;
 293         }
 294
 295         pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
 296                         ctx->key_size, NULL);
 297
 298         akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
 299         akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
 300                         pkcs1pad_encrypt_sign_complete_cb, req);
 301
 302         err = crypto_akcipher_encrypt(&req_ctx->child_req);
 303         if (err != -EINPROGRESS &&
 304                         (err != -EBUSY ||
 305                          !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
 306                 return pkcs1pad_encrypt_sign_complete(req, err);
 307
 308         return err;
 309 }
 310
 311 static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
 312 {
 313         struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 314         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 315         struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
 316         unsigned int pos;
 317
 318         if (err == -EOVERFLOW)
 319                 /* Decrypted value had no leading 0 byte */
 320                 err = -EINVAL;
 321
 322         if (err)
 323                 goto done;
 324
 325         if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
 326                 err = -EINVAL;
 327                 goto done;
 328         }
 329
 330         if (req_ctx->out_buf[0] != 0x02) {
 331                 err = -EINVAL;
 332                 goto done;
 333         }
 334         for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
 335                 if (req_ctx->out_buf[pos] == 0x00)
 336                         break;
 337         if (pos < 9 || pos == req_ctx->child_req.dst_len) {
 338                 err = -EINVAL;
 339                 goto done;
 340         }
 341         pos++;
 342
 343         if (req->dst_len < req_ctx->child_req.dst_len - pos)
 344                 err = -EOVERFLOW;
 345         req->dst_len = req_ctx->child_req.dst_len - pos;
 346
 347         if (!err)
 348                 sg_copy_from_buffer(req->dst,
 349                                 sg_nents_for_len(req->dst, req->dst_len),
 350                                 req_ctx->out_buf + pos, req->dst_len);
 351
 352 done:
 353         kzfree(req_ctx->out_buf);
 354
 355         return err;
 356 }
 357
 358 static void pkcs1pad_decrypt_complete_cb(
 359                 struct crypto_async_request *child_async_req, int err)
 360 {
 361         struct akcipher_request *req = child_async_req->data;
 362         struct crypto_async_request async_req;
 363
 364         if (err == -EINPROGRESS)
 365                 return;
 366
 367         async_req.data = req->base.data;
 368         async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
 369         async_req.flags = child_async_req->flags;
 370         req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
 371 }
 372
 373 static int pkcs1pad_decrypt(struct akcipher_request *req)
 374 {
 375         struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 376         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 377         struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
 378         int err;
 379
 380         if (!ctx->key_size || req->src_len != ctx->key_size)
 381                 return -EINVAL;
 382
 383         if (ctx->key_size > PAGE_SIZE)
 384                 return -ENOTSUPP;
 385
 386         /* Reuse input buffer, output to a new buffer */
 387         req_ctx->child_req.src = req->src;
 388         req_ctx->child_req.src_len = req->src_len;
 389         req_ctx->child_req.dst = req_ctx->out_sg;
 390         req_ctx->child_req.dst_len = ctx->key_size ;
 391
 392         req_ctx->out_buf = kmalloc(ctx->key_size,
 393                         (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 394                         GFP_KERNEL : GFP_ATOMIC);
 395         if (!req_ctx->out_buf)
 396                 return -ENOMEM;
 397
 398         pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
 399                             ctx->key_size, NULL);
 400
 401         akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
 402         akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
 403                         pkcs1pad_decrypt_complete_cb, req);
 404
 405         err = crypto_akcipher_decrypt(&req_ctx->child_req);
 406         if (err != -EINPROGRESS &&
 407                         (err != -EBUSY ||
 408                          !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
 409                 return pkcs1pad_decrypt_complete(req, err);
 410
 411         return err;
 412 }
 413
 414 static int pkcs1pad_sign(struct akcipher_request *req)
 415 {
 416         struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 417         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 418         struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
 419         const struct rsa_asn1_template *digest_info = NULL;
 420         int err;
 421         unsigned int ps_end, digest_size = 0;
 422
 423         if (!ctx->key_size)
 424                 return -EINVAL;
 425
 426         if (ctx->hash_name) {
 427                 digest_info = rsa_lookup_asn1(ctx->hash_name);
 428                 if (!digest_info)
 429                         return -EINVAL;
 430
 431                 digest_size = digest_info->size;
 432         }
 433
 434         if (req->src_len + digest_size > ctx->key_size - 11)
 435                 return -EOVERFLOW;
 436
 437         if (req->dst_len < ctx->key_size) {
 438                 req->dst_len = ctx->key_size;
 439                 return -EOVERFLOW;
 440         }
 441
 442         if (ctx->key_size > PAGE_SIZE)
 443                 return -ENOTSUPP;
 444
 445         /*
 446          * Replace both input and output to add the padding in the input and
 447          * the potential missing leading zeros in the output.
 448          */
 449         req_ctx->child_req.src = req_ctx->in_sg;
 450         req_ctx->child_req.src_len = ctx->key_size - 1;
 451         req_ctx->child_req.dst = req_ctx->out_sg;
 452         req_ctx->child_req.dst_len = ctx->key_size;
 453
 454         req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
 455                         (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 456                         GFP_KERNEL : GFP_ATOMIC);
 457         if (!req_ctx->in_buf)
 458                 return -ENOMEM;
 459
 460         ps_end = ctx->key_size - digest_size - req->src_len - 2;
 461         req_ctx->in_buf[0] = 0x01;
 462         memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
 463         req_ctx->in_buf[ps_end] = 0x00;
 464
 465         if (digest_info) {
 466                 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
 467                        digest_info->size);
 468         }
 469
 470         pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
 471                         ctx->key_size - 1 - req->src_len, req->src);
 472
 473         req_ctx->out_buf = kmalloc(ctx->key_size,
 474                         (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 475                         GFP_KERNEL : GFP_ATOMIC);
 476         if (!req_ctx->out_buf) {
 477                 kfree(req_ctx->in_buf);
 478                 return -ENOMEM;
 479         }
 480
 481         pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
 482                         ctx->key_size, NULL);
 483
 484         akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
 485         akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
 486                         pkcs1pad_encrypt_sign_complete_cb, req);
 487
 488         err = crypto_akcipher_sign(&req_ctx->child_req);
 489         if (err != -EINPROGRESS &&
 490                         (err != -EBUSY ||
 491                          !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
 492                 return pkcs1pad_encrypt_sign_complete(req, err);
 493
 494         return err;
 495 }
 496
 497 static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
 498 {
 499         struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 500         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 501         struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
 502         const struct rsa_asn1_template *digest_info;
 503         unsigned int pos;
 504
 505         if (err == -EOVERFLOW)
 506                 /* Decrypted value had no leading 0 byte */
 507                 err = -EINVAL;
 508
 509         if (err)
 510                 goto done;
 511
 512         if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
 513                 err = -EINVAL;
 514                 goto done;
 515         }
 516
 517         err = -EBADMSG;
 518         if (req_ctx->out_buf[0] != 0x01)
 519                 goto done;
 520
 521         for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
 522                 if (req_ctx->out_buf[pos] != 0xff)
 523                         break;
 524
 525         if (pos < 9 || pos == req_ctx->child_req.dst_len ||
 526             req_ctx->out_buf[pos] != 0x00)
 527                 goto done;
 528         pos++;
 529
 530         if (ctx->hash_name) {
 531                 digest_info = rsa_lookup_asn1(ctx->hash_name);
 532                 if (!digest_info)
 533                         goto done;
 534
 535                 if (memcmp(req_ctx->out_buf + pos, digest_info->data,
 536                            digest_info->size))
 537                         goto done;
 538
 539                 pos += digest_info->size;
 540         }
 541
 542         err = 0;
 543
 544         if (req->dst_len < req_ctx->child_req.dst_len - pos)
 545                 err = -EOVERFLOW;
 546         req->dst_len = req_ctx->child_req.dst_len - pos;
 547
 548         if (!err)
 549                 sg_copy_from_buffer(req->dst,
 550                                 sg_nents_for_len(req->dst, req->dst_len),
 551                                 req_ctx->out_buf + pos, req->dst_len);
 552 done:
 553         kzfree(req_ctx->out_buf);
 554
 555         return err;
 556 }
 557
 558 static void pkcs1pad_verify_complete_cb(
 559                 struct crypto_async_request *child_async_req, int err)
 560 {
 561         struct akcipher_request *req = child_async_req->data;
 562         struct crypto_async_request async_req;
 563
 564         if (err == -EINPROGRESS)
 565                 return;
 566
 567         async_req.data = req->base.data;
 568         async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
 569         async_req.flags = child_async_req->flags;
 570         req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
 571 }
 572
 573 /*
 574  * The verify operation is here for completeness similar to the verification
 575  * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
 576  * as in RFC2437.  RFC2437 section 9.2 doesn't define any operation to
 577  * retrieve the DigestInfo from a signature, instead the user is expected
 578  * to call the sign operation to generate the expected signature and compare
 579  * signatures instead of the message-digests.
 580  */
 581 static int pkcs1pad_verify(struct akcipher_request *req)
 582 {
 583         struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 584         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 585         struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
 586         int err;
 587
 588         if (!ctx->key_size || req->src_len < ctx->key_size)
 589                 return -EINVAL;
 590
 591         if (ctx->key_size > PAGE_SIZE)
 592                 return -ENOTSUPP;
 593
 594         /* Reuse input buffer, output to a new buffer */
 595         req_ctx->child_req.src = req->src;
 596         req_ctx->child_req.src_len = req->src_len;
 597         req_ctx->child_req.dst = req_ctx->out_sg;
 598         req_ctx->child_req.dst_len = ctx->key_size;
 599
 600         req_ctx->out_buf = kmalloc(ctx->key_size,
 601                         (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 602                         GFP_KERNEL : GFP_ATOMIC);
 603         if (!req_ctx->out_buf)
 604                 return -ENOMEM;
 605
 606         pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
 607                             ctx->key_size, NULL);
 608
 609         akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
 610         akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
 611                         pkcs1pad_verify_complete_cb, req);
 612
 613         err = crypto_akcipher_verify(&req_ctx->child_req);
 614         if (err != -EINPROGRESS &&
 615                         (err != -EBUSY ||
 616                          !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
 617                 return pkcs1pad_verify_complete(req, err);
 618
 619         return err;
 620 }
 621
 622 static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
 623 {
 624         struct akcipher_instance *inst = akcipher_alg_instance(tfm);
 625         struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
 626         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 627         struct crypto_akcipher *child_tfm;
 628
 629         child_tfm = crypto_spawn_akcipher(akcipher_instance_ctx(inst));
 630         if (IS_ERR(child_tfm))
 631                 return PTR_ERR(child_tfm);
 632
 633         ctx->child = child_tfm;
 634         ctx->hash_name = ictx->hash_name;
 635         return 0;
 636 }
 637
 638 static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
 639 {
 640         struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 641
 642         crypto_free_akcipher(ctx->child);
 643 }
 644
 645 static void pkcs1pad_free(struct akcipher_instance *inst)
 646 {
 647         struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
 648         struct crypto_akcipher_spawn *spawn = &ctx->spawn;
 649
 650         crypto_drop_akcipher(spawn);
 651         kfree(ctx->hash_name);
 652         kfree(inst);
 653 }
 654
 655 static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
 656 {
 657         struct crypto_attr_type *algt;
 658         struct akcipher_instance *inst;
 659         struct pkcs1pad_inst_ctx *ctx;
 660         struct crypto_akcipher_spawn *spawn;
 661         struct akcipher_alg *rsa_alg;
 662         const char *rsa_alg_name;
 663         const char *hash_name;
 664         int err;
 665
 666         algt = crypto_get_attr_type(tb);
 667         if (IS_ERR(algt))
 668                 return PTR_ERR(algt);
 669
 670         if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
 671                 return -EINVAL;
 672
 673         rsa_alg_name = crypto_attr_alg_name(tb[1]);
 674         if (IS_ERR(rsa_alg_name))
 675                 return PTR_ERR(rsa_alg_name);
 676
 677         hash_name = crypto_attr_alg_name(tb[2]);
 678         if (IS_ERR(hash_name))
 679                 hash_name = NULL;
 680
 681         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 682         if (!inst)
 683                 return -ENOMEM;
 684
 685         ctx = akcipher_instance_ctx(inst);
 686         spawn = &ctx->spawn;
 687         ctx->hash_name = hash_name ? kstrdup(hash_name, GFP_KERNEL) : NULL;
 688
 689         crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
 690         err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
 691                         crypto_requires_sync(algt->type, algt->mask));
 692         if (err)
 693                 goto out_free_inst;
 694
 695         rsa_alg = crypto_spawn_akcipher_alg(spawn);
 696
 697         err = -ENAMETOOLONG;
 698
 699         if (!hash_name) {
 700                 if (snprintf(inst->alg.base.cra_name,
 701                              CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
 702                              rsa_alg->base.cra_name) >=
 703                                         CRYPTO_MAX_ALG_NAME ||
 704                     snprintf(inst->alg.base.cra_driver_name,
 705                              CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
 706                              rsa_alg->base.cra_driver_name) >=
 707                                         CRYPTO_MAX_ALG_NAME)
 708                 goto out_drop_alg;
 709         } else {
 710                 if (snprintf(inst->alg.base.cra_name,
 711                              CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
 712                              rsa_alg->base.cra_name, hash_name) >=
 713                                 CRYPTO_MAX_ALG_NAME ||
 714                     snprintf(inst->alg.base.cra_driver_name,
 715                              CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
 716                              rsa_alg->base.cra_driver_name, hash_name) >=
 717                                         CRYPTO_MAX_ALG_NAME)
 718                 goto out_free_hash;
 719         }
 720
 721         inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 722         inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
 723         inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
 724
 725         inst->alg.init = pkcs1pad_init_tfm;
 726         inst->alg.exit = pkcs1pad_exit_tfm;
 727
 728         inst->alg.encrypt = pkcs1pad_encrypt;
 729         inst->alg.decrypt = pkcs1pad_decrypt;
 730         inst->alg.sign = pkcs1pad_sign;
 731         inst->alg.verify = pkcs1pad_verify;
 732         inst->alg.set_pub_key = pkcs1pad_set_pub_key;
 733         inst->alg.set_priv_key = pkcs1pad_set_priv_key;
 734         inst->alg.max_size = pkcs1pad_get_max_size;
 735         inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;
 736
 737         inst->free = pkcs1pad_free;
 738
 739         err = akcipher_register_instance(tmpl, inst);
 740         if (err)
 741                 goto out_free_hash;
 742
 743         return 0;
 744
 745 out_free_hash:
 746         kfree(ctx->hash_name);
 747 out_drop_alg:
 748         crypto_drop_akcipher(spawn);
 749 out_free_inst:
 750         kfree(inst);
 751         return err;
 752 }
 753
 754 struct crypto_template rsa_pkcs1pad_tmpl = {
 755         .name = "pkcs1pad",
 756         .create = pkcs1pad_create,
 757         .module = THIS_MODULE,
 758 };