LXR linux/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 */
  24static 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
  30static 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
  36static 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
  42static 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
  48static 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
  54static 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
  60static 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
  66static 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
  83static 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
  93struct pkcs1pad_ctx {
  94        struct crypto_akcipher *child;
  95        const char *hash_name;
  96        unsigned int key_size;
  97};
  98
  99struct pkcs1pad_inst_ctx {
 100        struct crypto_akcipher_spawn spawn;
 101        const char *hash_name;
 102};
 103
 104struct 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
 111static 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
 131static 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
 151static 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
 164static 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
 185static 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
 225static 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
 241static 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
 311static 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
 352done:
 353        kzfree(req_ctx->out_buf);
 354
 355        return err;
 356}
 357
 358static 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
 373static 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
 414static 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
 497static 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);
 552done:
 553        kzfree(req_ctx->out_buf);
 554
 555        return err;
 556}
 557
 558static 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 */
 581static 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
 622static 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
 638static 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
 645static 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
 655static 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
 745out_free_hash:
 746        kfree(ctx->hash_name);
 747out_drop_alg:
 748        crypto_drop_akcipher(spawn);
 749out_free_inst:
 750        kfree(inst);
 751        return err;
 752}
 753
 754struct crypto_template rsa_pkcs1pad_tmpl = {
 755        .name = "pkcs1pad",
 756        .create = pkcs1pad_create,
 757        .module = THIS_MODULE,
 758};
 759