linux/crypto/ccm.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * CCM: Counter with CBC-MAC
   4 *
   5 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
   6 */
   7
   8#include <crypto/internal/aead.h>
   9#include <crypto/internal/cipher.h>
  10#include <crypto/internal/hash.h>
  11#include <crypto/internal/skcipher.h>
  12#include <crypto/scatterwalk.h>
  13#include <linux/err.h>
  14#include <linux/init.h>
  15#include <linux/kernel.h>
  16#include <linux/module.h>
  17#include <linux/slab.h>
  18
  19struct ccm_instance_ctx {
  20        struct crypto_skcipher_spawn ctr;
  21        struct crypto_ahash_spawn mac;
  22};
  23
  24struct crypto_ccm_ctx {
  25        struct crypto_ahash *mac;
  26        struct crypto_skcipher *ctr;
  27};
  28
  29struct crypto_rfc4309_ctx {
  30        struct crypto_aead *child;
  31        u8 nonce[3];
  32};
  33
  34struct crypto_rfc4309_req_ctx {
  35        struct scatterlist src[3];
  36        struct scatterlist dst[3];
  37        struct aead_request subreq;
  38};
  39
  40struct crypto_ccm_req_priv_ctx {
  41        u8 odata[16];
  42        u8 idata[16];
  43        u8 auth_tag[16];
  44        u32 flags;
  45        struct scatterlist src[3];
  46        struct scatterlist dst[3];
  47        union {
  48                struct ahash_request ahreq;
  49                struct skcipher_request skreq;
  50        };
  51};
  52
  53struct cbcmac_tfm_ctx {
  54        struct crypto_cipher *child;
  55};
  56
  57struct cbcmac_desc_ctx {
  58        unsigned int len;
  59};
  60
  61static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
  62        struct aead_request *req)
  63{
  64        unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  65
  66        return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  67}
  68
  69static int set_msg_len(u8 *block, unsigned int msglen, int csize)
  70{
  71        __be32 data;
  72
  73        memset(block, 0, csize);
  74        block += csize;
  75
  76        if (csize >= 4)
  77                csize = 4;
  78        else if (msglen > (1 << (8 * csize)))
  79                return -EOVERFLOW;
  80
  81        data = cpu_to_be32(msglen);
  82        memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
  83
  84        return 0;
  85}
  86
  87static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
  88                             unsigned int keylen)
  89{
  90        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
  91        struct crypto_skcipher *ctr = ctx->ctr;
  92        struct crypto_ahash *mac = ctx->mac;
  93        int err;
  94
  95        crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
  96        crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
  97                                       CRYPTO_TFM_REQ_MASK);
  98        err = crypto_skcipher_setkey(ctr, key, keylen);
  99        if (err)
 100                return err;
 101
 102        crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
 103        crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
 104                                    CRYPTO_TFM_REQ_MASK);
 105        return crypto_ahash_setkey(mac, key, keylen);
 106}
 107
 108static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
 109                                  unsigned int authsize)
 110{
 111        switch (authsize) {
 112        case 4:
 113        case 6:
 114        case 8:
 115        case 10:
 116        case 12:
 117        case 14:
 118        case 16:
 119                break;
 120        default:
 121                return -EINVAL;
 122        }
 123
 124        return 0;
 125}
 126
 127static int format_input(u8 *info, struct aead_request *req,
 128                        unsigned int cryptlen)
 129{
 130        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 131        unsigned int lp = req->iv[0];
 132        unsigned int l = lp + 1;
 133        unsigned int m;
 134
 135        m = crypto_aead_authsize(aead);
 136
 137        memcpy(info, req->iv, 16);
 138
 139        /* format control info per RFC 3610 and
 140         * NIST Special Publication 800-38C
 141         */
 142        *info |= (8 * ((m - 2) / 2));
 143        if (req->assoclen)
 144                *info |= 64;
 145
 146        return set_msg_len(info + 16 - l, cryptlen, l);
 147}
 148
 149static int format_adata(u8 *adata, unsigned int a)
 150{
 151        int len = 0;
 152
 153        /* add control info for associated data
 154         * RFC 3610 and NIST Special Publication 800-38C
 155         */
 156        if (a < 65280) {
 157                *(__be16 *)adata = cpu_to_be16(a);
 158                len = 2;
 159        } else  {
 160                *(__be16 *)adata = cpu_to_be16(0xfffe);
 161                *(__be32 *)&adata[2] = cpu_to_be32(a);
 162                len = 6;
 163        }
 164
 165        return len;
 166}
 167
 168static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
 169                           unsigned int cryptlen)
 170{
 171        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 172        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 173        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 174        struct ahash_request *ahreq = &pctx->ahreq;
 175        unsigned int assoclen = req->assoclen;
 176        struct scatterlist sg[3];
 177        u8 *odata = pctx->odata;
 178        u8 *idata = pctx->idata;
 179        int ilen, err;
 180
 181        /* format control data for input */
 182        err = format_input(odata, req, cryptlen);
 183        if (err)
 184                goto out;
 185
 186        sg_init_table(sg, 3);
 187        sg_set_buf(&sg[0], odata, 16);
 188
 189        /* format associated data and compute into mac */
 190        if (assoclen) {
 191                ilen = format_adata(idata, assoclen);
 192                sg_set_buf(&sg[1], idata, ilen);
 193                sg_chain(sg, 3, req->src);
 194        } else {
 195                ilen = 0;
 196                sg_chain(sg, 2, req->src);
 197        }
 198
 199        ahash_request_set_tfm(ahreq, ctx->mac);
 200        ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
 201        ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
 202        err = crypto_ahash_init(ahreq);
 203        if (err)
 204                goto out;
 205        err = crypto_ahash_update(ahreq);
 206        if (err)
 207                goto out;
 208
 209        /* we need to pad the MAC input to a round multiple of the block size */
 210        ilen = 16 - (assoclen + ilen) % 16;
 211        if (ilen < 16) {
 212                memset(idata, 0, ilen);
 213                sg_init_table(sg, 2);
 214                sg_set_buf(&sg[0], idata, ilen);
 215                if (plain)
 216                        sg_chain(sg, 2, plain);
 217                plain = sg;
 218                cryptlen += ilen;
 219        }
 220
 221        ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
 222        err = crypto_ahash_finup(ahreq);
 223out:
 224        return err;
 225}
 226
 227static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
 228{
 229        struct aead_request *req = areq->data;
 230        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 231        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 232        u8 *odata = pctx->odata;
 233
 234        if (!err)
 235                scatterwalk_map_and_copy(odata, req->dst,
 236                                         req->assoclen + req->cryptlen,
 237                                         crypto_aead_authsize(aead), 1);
 238        aead_request_complete(req, err);
 239}
 240
 241static inline int crypto_ccm_check_iv(const u8 *iv)
 242{
 243        /* 2 <= L <= 8, so 1 <= L' <= 7. */
 244        if (1 > iv[0] || iv[0] > 7)
 245                return -EINVAL;
 246
 247        return 0;
 248}
 249
 250static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
 251{
 252        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 253        struct scatterlist *sg;
 254        u8 *iv = req->iv;
 255        int err;
 256
 257        err = crypto_ccm_check_iv(iv);
 258        if (err)
 259                return err;
 260
 261        pctx->flags = aead_request_flags(req);
 262
 263         /* Note: rfc 3610 and NIST 800-38C require counter of
 264         * zero to encrypt auth tag.
 265         */
 266        memset(iv + 15 - iv[0], 0, iv[0] + 1);
 267
 268        sg_init_table(pctx->src, 3);
 269        sg_set_buf(pctx->src, tag, 16);
 270        sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 271        if (sg != pctx->src + 1)
 272                sg_chain(pctx->src, 2, sg);
 273
 274        if (req->src != req->dst) {
 275                sg_init_table(pctx->dst, 3);
 276                sg_set_buf(pctx->dst, tag, 16);
 277                sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 278                if (sg != pctx->dst + 1)
 279                        sg_chain(pctx->dst, 2, sg);
 280        }
 281
 282        return 0;
 283}
 284
 285static int crypto_ccm_encrypt(struct aead_request *req)
 286{
 287        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 288        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 289        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 290        struct skcipher_request *skreq = &pctx->skreq;
 291        struct scatterlist *dst;
 292        unsigned int cryptlen = req->cryptlen;
 293        u8 *odata = pctx->odata;
 294        u8 *iv = req->iv;
 295        int err;
 296
 297        err = crypto_ccm_init_crypt(req, odata);
 298        if (err)
 299                return err;
 300
 301        err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
 302        if (err)
 303                return err;
 304
 305        dst = pctx->src;
 306        if (req->src != req->dst)
 307                dst = pctx->dst;
 308
 309        skcipher_request_set_tfm(skreq, ctx->ctr);
 310        skcipher_request_set_callback(skreq, pctx->flags,
 311                                      crypto_ccm_encrypt_done, req);
 312        skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 313        err = crypto_skcipher_encrypt(skreq);
 314        if (err)
 315                return err;
 316
 317        /* copy authtag to end of dst */
 318        scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
 319                                 crypto_aead_authsize(aead), 1);
 320        return err;
 321}
 322
 323static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
 324                                   int err)
 325{
 326        struct aead_request *req = areq->data;
 327        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 328        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 329        unsigned int authsize = crypto_aead_authsize(aead);
 330        unsigned int cryptlen = req->cryptlen - authsize;
 331        struct scatterlist *dst;
 332
 333        pctx->flags = 0;
 334
 335        dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 336
 337        if (!err) {
 338                err = crypto_ccm_auth(req, dst, cryptlen);
 339                if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
 340                        err = -EBADMSG;
 341        }
 342        aead_request_complete(req, err);
 343}
 344
 345static int crypto_ccm_decrypt(struct aead_request *req)
 346{
 347        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 348        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
 349        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
 350        struct skcipher_request *skreq = &pctx->skreq;
 351        struct scatterlist *dst;
 352        unsigned int authsize = crypto_aead_authsize(aead);
 353        unsigned int cryptlen = req->cryptlen;
 354        u8 *authtag = pctx->auth_tag;
 355        u8 *odata = pctx->odata;
 356        u8 *iv = pctx->idata;
 357        int err;
 358
 359        cryptlen -= authsize;
 360
 361        err = crypto_ccm_init_crypt(req, authtag);
 362        if (err)
 363                return err;
 364
 365        scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
 366                                 authsize, 0);
 367
 368        dst = pctx->src;
 369        if (req->src != req->dst)
 370                dst = pctx->dst;
 371
 372        memcpy(iv, req->iv, 16);
 373
 374        skcipher_request_set_tfm(skreq, ctx->ctr);
 375        skcipher_request_set_callback(skreq, pctx->flags,
 376                                      crypto_ccm_decrypt_done, req);
 377        skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
 378        err = crypto_skcipher_decrypt(skreq);
 379        if (err)
 380                return err;
 381
 382        err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
 383        if (err)
 384                return err;
 385
 386        /* verify */
 387        if (crypto_memneq(authtag, odata, authsize))
 388                return -EBADMSG;
 389
 390        return err;
 391}
 392
 393static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
 394{
 395        struct aead_instance *inst = aead_alg_instance(tfm);
 396        struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
 397        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 398        struct crypto_ahash *mac;
 399        struct crypto_skcipher *ctr;
 400        unsigned long align;
 401        int err;
 402
 403        mac = crypto_spawn_ahash(&ictx->mac);
 404        if (IS_ERR(mac))
 405                return PTR_ERR(mac);
 406
 407        ctr = crypto_spawn_skcipher(&ictx->ctr);
 408        err = PTR_ERR(ctr);
 409        if (IS_ERR(ctr))
 410                goto err_free_mac;
 411
 412        ctx->mac = mac;
 413        ctx->ctr = ctr;
 414
 415        align = crypto_aead_alignmask(tfm);
 416        align &= ~(crypto_tfm_ctx_alignment() - 1);
 417        crypto_aead_set_reqsize(
 418                tfm,
 419                align + sizeof(struct crypto_ccm_req_priv_ctx) +
 420                max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
 421
 422        return 0;
 423
 424err_free_mac:
 425        crypto_free_ahash(mac);
 426        return err;
 427}
 428
 429static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
 430{
 431        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
 432
 433        crypto_free_ahash(ctx->mac);
 434        crypto_free_skcipher(ctx->ctr);
 435}
 436
 437static void crypto_ccm_free(struct aead_instance *inst)
 438{
 439        struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
 440
 441        crypto_drop_ahash(&ctx->mac);
 442        crypto_drop_skcipher(&ctx->ctr);
 443        kfree(inst);
 444}
 445
 446static int crypto_ccm_create_common(struct crypto_template *tmpl,
 447                                    struct rtattr **tb,
 448                                    const char *ctr_name,
 449                                    const char *mac_name)
 450{
 451        u32 mask;
 452        struct aead_instance *inst;
 453        struct ccm_instance_ctx *ictx;
 454        struct skcipher_alg *ctr;
 455        struct hash_alg_common *mac;
 456        int err;
 457
 458        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 459        if (err)
 460                return err;
 461
 462        inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 463        if (!inst)
 464                return -ENOMEM;
 465        ictx = aead_instance_ctx(inst);
 466
 467        err = crypto_grab_ahash(&ictx->mac, aead_crypto_instance(inst),
 468                                mac_name, 0, mask | CRYPTO_ALG_ASYNC);
 469        if (err)
 470                goto err_free_inst;
 471        mac = crypto_spawn_ahash_alg(&ictx->mac);
 472
 473        err = -EINVAL;
 474        if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
 475            mac->digestsize != 16)
 476                goto err_free_inst;
 477
 478        err = crypto_grab_skcipher(&ictx->ctr, aead_crypto_instance(inst),
 479                                   ctr_name, 0, mask);
 480        if (err)
 481                goto err_free_inst;
 482        ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
 483
 484        /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
 485        err = -EINVAL;
 486        if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
 487            crypto_skcipher_alg_ivsize(ctr) != 16 ||
 488            ctr->base.cra_blocksize != 1)
 489                goto err_free_inst;
 490
 491        /* ctr and cbcmac must use the same underlying block cipher. */
 492        if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
 493                goto err_free_inst;
 494
 495        err = -ENAMETOOLONG;
 496        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 497                     "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
 498                goto err_free_inst;
 499
 500        if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 501                     "ccm_base(%s,%s)", ctr->base.cra_driver_name,
 502                     mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 503                goto err_free_inst;
 504
 505        inst->alg.base.cra_priority = (mac->base.cra_priority +
 506                                       ctr->base.cra_priority) / 2;
 507        inst->alg.base.cra_blocksize = 1;
 508        inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
 509                                       ctr->base.cra_alignmask;
 510        inst->alg.ivsize = 16;
 511        inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
 512        inst->alg.maxauthsize = 16;
 513        inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
 514        inst->alg.init = crypto_ccm_init_tfm;
 515        inst->alg.exit = crypto_ccm_exit_tfm;
 516        inst->alg.setkey = crypto_ccm_setkey;
 517        inst->alg.setauthsize = crypto_ccm_setauthsize;
 518        inst->alg.encrypt = crypto_ccm_encrypt;
 519        inst->alg.decrypt = crypto_ccm_decrypt;
 520
 521        inst->free = crypto_ccm_free;
 522
 523        err = aead_register_instance(tmpl, inst);
 524        if (err) {
 525err_free_inst:
 526                crypto_ccm_free(inst);
 527        }
 528        return err;
 529}
 530
 531static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
 532{
 533        const char *cipher_name;
 534        char ctr_name[CRYPTO_MAX_ALG_NAME];
 535        char mac_name[CRYPTO_MAX_ALG_NAME];
 536
 537        cipher_name = crypto_attr_alg_name(tb[1]);
 538        if (IS_ERR(cipher_name))
 539                return PTR_ERR(cipher_name);
 540
 541        if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
 542                     cipher_name) >= CRYPTO_MAX_ALG_NAME)
 543                return -ENAMETOOLONG;
 544
 545        if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
 546                     cipher_name) >= CRYPTO_MAX_ALG_NAME)
 547                return -ENAMETOOLONG;
 548
 549        return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
 550}
 551
 552static int crypto_ccm_base_create(struct crypto_template *tmpl,
 553                                  struct rtattr **tb)
 554{
 555        const char *ctr_name;
 556        const char *mac_name;
 557
 558        ctr_name = crypto_attr_alg_name(tb[1]);
 559        if (IS_ERR(ctr_name))
 560                return PTR_ERR(ctr_name);
 561
 562        mac_name = crypto_attr_alg_name(tb[2]);
 563        if (IS_ERR(mac_name))
 564                return PTR_ERR(mac_name);
 565
 566        return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
 567}
 568
 569static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
 570                                 unsigned int keylen)
 571{
 572        struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 573        struct crypto_aead *child = ctx->child;
 574
 575        if (keylen < 3)
 576                return -EINVAL;
 577
 578        keylen -= 3;
 579        memcpy(ctx->nonce, key + keylen, 3);
 580
 581        crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 582        crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 583                                     CRYPTO_TFM_REQ_MASK);
 584        return crypto_aead_setkey(child, key, keylen);
 585}
 586
 587static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
 588                                      unsigned int authsize)
 589{
 590        struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
 591
 592        switch (authsize) {
 593        case 8:
 594        case 12:
 595        case 16:
 596                break;
 597        default:
 598                return -EINVAL;
 599        }
 600
 601        return crypto_aead_setauthsize(ctx->child, authsize);
 602}
 603
 604static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
 605{
 606        struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
 607        struct aead_request *subreq = &rctx->subreq;
 608        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 609        struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
 610        struct crypto_aead *child = ctx->child;
 611        struct scatterlist *sg;
 612        u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 613                           crypto_aead_alignmask(child) + 1);
 614
 615        /* L' */
 616        iv[0] = 3;
 617
 618        memcpy(iv + 1, ctx->nonce, 3);
 619        memcpy(iv + 4, req->iv, 8);
 620
 621        scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
 622
 623        sg_init_table(rctx->src, 3);
 624        sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
 625        sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 626        if (sg != rctx->src + 1)
 627                sg_chain(rctx->src, 2, sg);
 628
 629        if (req->src != req->dst) {
 630                sg_init_table(rctx->dst, 3);
 631                sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
 632                sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 633                if (sg != rctx->dst + 1)
 634                        sg_chain(rctx->dst, 2, sg);
 635        }
 636
 637        aead_request_set_tfm(subreq, child);
 638        aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 639                                  req->base.data);
 640        aead_request_set_crypt(subreq, rctx->src,
 641                               req->src == req->dst ? rctx->src : rctx->dst,
 642                               req->cryptlen, iv);
 643        aead_request_set_ad(subreq, req->assoclen - 8);
 644
 645        return subreq;
 646}
 647
 648static int crypto_rfc4309_encrypt(struct aead_request *req)
 649{
 650        if (req->assoclen != 16 && req->assoclen != 20)
 651                return -EINVAL;
 652
 653        req = crypto_rfc4309_crypt(req);
 654
 655        return crypto_aead_encrypt(req);
 656}
 657
 658static int crypto_rfc4309_decrypt(struct aead_request *req)
 659{
 660        if (req->assoclen != 16 && req->assoclen != 20)
 661                return -EINVAL;
 662
 663        req = crypto_rfc4309_crypt(req);
 664
 665        return crypto_aead_decrypt(req);
 666}
 667
 668static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
 669{
 670        struct aead_instance *inst = aead_alg_instance(tfm);
 671        struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 672        struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 673        struct crypto_aead *aead;
 674        unsigned long align;
 675
 676        aead = crypto_spawn_aead(spawn);
 677        if (IS_ERR(aead))
 678                return PTR_ERR(aead);
 679
 680        ctx->child = aead;
 681
 682        align = crypto_aead_alignmask(aead);
 683        align &= ~(crypto_tfm_ctx_alignment() - 1);
 684        crypto_aead_set_reqsize(
 685                tfm,
 686                sizeof(struct crypto_rfc4309_req_ctx) +
 687                ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 688                align + 32);
 689
 690        return 0;
 691}
 692
 693static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
 694{
 695        struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
 696
 697        crypto_free_aead(ctx->child);
 698}
 699
 700static void crypto_rfc4309_free(struct aead_instance *inst)
 701{
 702        crypto_drop_aead(aead_instance_ctx(inst));
 703        kfree(inst);
 704}
 705
 706static int crypto_rfc4309_create(struct crypto_template *tmpl,
 707                                 struct rtattr **tb)
 708{
 709        u32 mask;
 710        struct aead_instance *inst;
 711        struct crypto_aead_spawn *spawn;
 712        struct aead_alg *alg;
 713        int err;
 714
 715        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 716        if (err)
 717                return err;
 718
 719        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 720        if (!inst)
 721                return -ENOMEM;
 722
 723        spawn = aead_instance_ctx(inst);
 724        err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
 725                               crypto_attr_alg_name(tb[1]), 0, mask);
 726        if (err)
 727                goto err_free_inst;
 728
 729        alg = crypto_spawn_aead_alg(spawn);
 730
 731        err = -EINVAL;
 732
 733        /* We only support 16-byte blocks. */
 734        if (crypto_aead_alg_ivsize(alg) != 16)
 735                goto err_free_inst;
 736
 737        /* Not a stream cipher? */
 738        if (alg->base.cra_blocksize != 1)
 739                goto err_free_inst;
 740
 741        err = -ENAMETOOLONG;
 742        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 743                     "rfc4309(%s)", alg->base.cra_name) >=
 744            CRYPTO_MAX_ALG_NAME ||
 745            snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 746                     "rfc4309(%s)", alg->base.cra_driver_name) >=
 747            CRYPTO_MAX_ALG_NAME)
 748                goto err_free_inst;
 749
 750        inst->alg.base.cra_priority = alg->base.cra_priority;
 751        inst->alg.base.cra_blocksize = 1;
 752        inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 753
 754        inst->alg.ivsize = 8;
 755        inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 756        inst->alg.maxauthsize = 16;
 757
 758        inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
 759
 760        inst->alg.init = crypto_rfc4309_init_tfm;
 761        inst->alg.exit = crypto_rfc4309_exit_tfm;
 762
 763        inst->alg.setkey = crypto_rfc4309_setkey;
 764        inst->alg.setauthsize = crypto_rfc4309_setauthsize;
 765        inst->alg.encrypt = crypto_rfc4309_encrypt;
 766        inst->alg.decrypt = crypto_rfc4309_decrypt;
 767
 768        inst->free = crypto_rfc4309_free;
 769
 770        err = aead_register_instance(tmpl, inst);
 771        if (err) {
 772err_free_inst:
 773                crypto_rfc4309_free(inst);
 774        }
 775        return err;
 776}
 777
 778static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
 779                                     const u8 *inkey, unsigned int keylen)
 780{
 781        struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
 782
 783        return crypto_cipher_setkey(ctx->child, inkey, keylen);
 784}
 785
 786static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
 787{
 788        struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 789        int bs = crypto_shash_digestsize(pdesc->tfm);
 790        u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
 791
 792        ctx->len = 0;
 793        memset(dg, 0, bs);
 794
 795        return 0;
 796}
 797
 798static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
 799                                       unsigned int len)
 800{
 801        struct crypto_shash *parent = pdesc->tfm;
 802        struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 803        struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 804        struct crypto_cipher *tfm = tctx->child;
 805        int bs = crypto_shash_digestsize(parent);
 806        u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 807
 808        while (len > 0) {
 809                unsigned int l = min(len, bs - ctx->len);
 810
 811                crypto_xor(dg + ctx->len, p, l);
 812                ctx->len +=l;
 813                len -= l;
 814                p += l;
 815
 816                if (ctx->len == bs) {
 817                        crypto_cipher_encrypt_one(tfm, dg, dg);
 818                        ctx->len = 0;
 819                }
 820        }
 821
 822        return 0;
 823}
 824
 825static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
 826{
 827        struct crypto_shash *parent = pdesc->tfm;
 828        struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
 829        struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
 830        struct crypto_cipher *tfm = tctx->child;
 831        int bs = crypto_shash_digestsize(parent);
 832        u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
 833
 834        if (ctx->len)
 835                crypto_cipher_encrypt_one(tfm, dg, dg);
 836
 837        memcpy(out, dg, bs);
 838        return 0;
 839}
 840
 841static int cbcmac_init_tfm(struct crypto_tfm *tfm)
 842{
 843        struct crypto_cipher *cipher;
 844        struct crypto_instance *inst = (void *)tfm->__crt_alg;
 845        struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);
 846        struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 847
 848        cipher = crypto_spawn_cipher(spawn);
 849        if (IS_ERR(cipher))
 850                return PTR_ERR(cipher);
 851
 852        ctx->child = cipher;
 853
 854        return 0;
 855};
 856
 857static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
 858{
 859        struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
 860        crypto_free_cipher(ctx->child);
 861}
 862
 863static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 864{
 865        struct shash_instance *inst;
 866        struct crypto_cipher_spawn *spawn;
 867        struct crypto_alg *alg;
 868        u32 mask;
 869        int err;
 870
 871        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
 872        if (err)
 873                return err;
 874
 875        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 876        if (!inst)
 877                return -ENOMEM;
 878        spawn = shash_instance_ctx(inst);
 879
 880        err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
 881                                 crypto_attr_alg_name(tb[1]), 0, mask);
 882        if (err)
 883                goto err_free_inst;
 884        alg = crypto_spawn_cipher_alg(spawn);
 885
 886        err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
 887        if (err)
 888                goto err_free_inst;
 889
 890        inst->alg.base.cra_priority = alg->cra_priority;
 891        inst->alg.base.cra_blocksize = 1;
 892
 893        inst->alg.digestsize = alg->cra_blocksize;
 894        inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
 895                                   alg->cra_alignmask + 1) +
 896                             alg->cra_blocksize;
 897
 898        inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
 899        inst->alg.base.cra_init = cbcmac_init_tfm;
 900        inst->alg.base.cra_exit = cbcmac_exit_tfm;
 901
 902        inst->alg.init = crypto_cbcmac_digest_init;
 903        inst->alg.update = crypto_cbcmac_digest_update;
 904        inst->alg.final = crypto_cbcmac_digest_final;
 905        inst->alg.setkey = crypto_cbcmac_digest_setkey;
 906
 907        inst->free = shash_free_singlespawn_instance;
 908
 909        err = shash_register_instance(tmpl, inst);
 910        if (err) {
 911err_free_inst:
 912                shash_free_singlespawn_instance(inst);
 913        }
 914        return err;
 915}
 916
 917static struct crypto_template crypto_ccm_tmpls[] = {
 918        {
 919                .name = "cbcmac",
 920                .create = cbcmac_create,
 921                .module = THIS_MODULE,
 922        }, {
 923                .name = "ccm_base",
 924                .create = crypto_ccm_base_create,
 925                .module = THIS_MODULE,
 926        }, {
 927                .name = "ccm",
 928                .create = crypto_ccm_create,
 929                .module = THIS_MODULE,
 930        }, {
 931                .name = "rfc4309",
 932                .create = crypto_rfc4309_create,
 933                .module = THIS_MODULE,
 934        },
 935};
 936
 937static int __init crypto_ccm_module_init(void)
 938{
 939        return crypto_register_templates(crypto_ccm_tmpls,
 940                                         ARRAY_SIZE(crypto_ccm_tmpls));
 941}
 942
 943static void __exit crypto_ccm_module_exit(void)
 944{
 945        crypto_unregister_templates(crypto_ccm_tmpls,
 946                                    ARRAY_SIZE(crypto_ccm_tmpls));
 947}
 948
 949subsys_initcall(crypto_ccm_module_init);
 950module_exit(crypto_ccm_module_exit);
 951
 952MODULE_LICENSE("GPL");
 953MODULE_DESCRIPTION("Counter with CBC MAC");
 954MODULE_ALIAS_CRYPTO("ccm_base");
 955MODULE_ALIAS_CRYPTO("rfc4309");
 956MODULE_ALIAS_CRYPTO("ccm");
 957MODULE_ALIAS_CRYPTO("cbcmac");
 958MODULE_IMPORT_NS(CRYPTO_INTERNAL);
 959
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