linux/crypto/gcm.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * GCM: Galois/Counter Mode.
   4 *
   5 * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
   6 */
   7
   8#include <crypto/gf128mul.h>
   9#include <crypto/internal/aead.h>
  10#include <crypto/internal/skcipher.h>
  11#include <crypto/internal/hash.h>
  12#include <crypto/null.h>
  13#include <crypto/scatterwalk.h>
  14#include <crypto/gcm.h>
  15#include <crypto/hash.h>
  16#include <linux/err.h>
  17#include <linux/init.h>
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/slab.h>
  21
  22struct gcm_instance_ctx {
  23        struct crypto_skcipher_spawn ctr;
  24        struct crypto_ahash_spawn ghash;
  25};
  26
  27struct crypto_gcm_ctx {
  28        struct crypto_skcipher *ctr;
  29        struct crypto_ahash *ghash;
  30};
  31
  32struct crypto_rfc4106_ctx {
  33        struct crypto_aead *child;
  34        u8 nonce[4];
  35};
  36
  37struct crypto_rfc4106_req_ctx {
  38        struct scatterlist src[3];
  39        struct scatterlist dst[3];
  40        struct aead_request subreq;
  41};
  42
  43struct crypto_rfc4543_instance_ctx {
  44        struct crypto_aead_spawn aead;
  45};
  46
  47struct crypto_rfc4543_ctx {
  48        struct crypto_aead *child;
  49        struct crypto_sync_skcipher *null;
  50        u8 nonce[4];
  51};
  52
  53struct crypto_rfc4543_req_ctx {
  54        struct aead_request subreq;
  55};
  56
  57struct crypto_gcm_ghash_ctx {
  58        unsigned int cryptlen;
  59        struct scatterlist *src;
  60        int (*complete)(struct aead_request *req, u32 flags);
  61};
  62
  63struct crypto_gcm_req_priv_ctx {
  64        u8 iv[16];
  65        u8 auth_tag[16];
  66        u8 iauth_tag[16];
  67        struct scatterlist src[3];
  68        struct scatterlist dst[3];
  69        struct scatterlist sg;
  70        struct crypto_gcm_ghash_ctx ghash_ctx;
  71        union {
  72                struct ahash_request ahreq;
  73                struct skcipher_request skreq;
  74        } u;
  75};
  76
  77static struct {
  78        u8 buf[16];
  79        struct scatterlist sg;
  80} *gcm_zeroes;
  81
  82static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc);
  83
  84static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
  85        struct aead_request *req)
  86{
  87        unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
  88
  89        return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
  90}
  91
  92static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
  93                             unsigned int keylen)
  94{
  95        struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
  96        struct crypto_ahash *ghash = ctx->ghash;
  97        struct crypto_skcipher *ctr = ctx->ctr;
  98        struct {
  99                be128 hash;
 100                u8 iv[16];
 101
 102                struct crypto_wait wait;
 103
 104                struct scatterlist sg[1];
 105                struct skcipher_request req;
 106        } *data;
 107        int err;
 108
 109        crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
 110        crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
 111                                       CRYPTO_TFM_REQ_MASK);
 112        err = crypto_skcipher_setkey(ctr, key, keylen);
 113        if (err)
 114                return err;
 115
 116        data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr),
 117                       GFP_KERNEL);
 118        if (!data)
 119                return -ENOMEM;
 120
 121        crypto_init_wait(&data->wait);
 122        sg_init_one(data->sg, &data->hash, sizeof(data->hash));
 123        skcipher_request_set_tfm(&data->req, ctr);
 124        skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
 125                                                  CRYPTO_TFM_REQ_MAY_BACKLOG,
 126                                      crypto_req_done,
 127                                      &data->wait);
 128        skcipher_request_set_crypt(&data->req, data->sg, data->sg,
 129                                   sizeof(data->hash), data->iv);
 130
 131        err = crypto_wait_req(crypto_skcipher_encrypt(&data->req),
 132                                                        &data->wait);
 133
 134        if (err)
 135                goto out;
 136
 137        crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK);
 138        crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) &
 139                               CRYPTO_TFM_REQ_MASK);
 140        err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
 141out:
 142        kfree_sensitive(data);
 143        return err;
 144}
 145
 146static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
 147                                  unsigned int authsize)
 148{
 149        return crypto_gcm_check_authsize(authsize);
 150}
 151
 152static void crypto_gcm_init_common(struct aead_request *req)
 153{
 154        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 155        __be32 counter = cpu_to_be32(1);
 156        struct scatterlist *sg;
 157
 158        memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
 159        memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE);
 160        memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4);
 161
 162        sg_init_table(pctx->src, 3);
 163        sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
 164        sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
 165        if (sg != pctx->src + 1)
 166                sg_chain(pctx->src, 2, sg);
 167
 168        if (req->src != req->dst) {
 169                sg_init_table(pctx->dst, 3);
 170                sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
 171                sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
 172                if (sg != pctx->dst + 1)
 173                        sg_chain(pctx->dst, 2, sg);
 174        }
 175}
 176
 177static void crypto_gcm_init_crypt(struct aead_request *req,
 178                                  unsigned int cryptlen)
 179{
 180        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 181        struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
 182        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 183        struct skcipher_request *skreq = &pctx->u.skreq;
 184        struct scatterlist *dst;
 185
 186        dst = req->src == req->dst ? pctx->src : pctx->dst;
 187
 188        skcipher_request_set_tfm(skreq, ctx->ctr);
 189        skcipher_request_set_crypt(skreq, pctx->src, dst,
 190                                     cryptlen + sizeof(pctx->auth_tag),
 191                                     pctx->iv);
 192}
 193
 194static inline unsigned int gcm_remain(unsigned int len)
 195{
 196        len &= 0xfU;
 197        return len ? 16 - len : 0;
 198}
 199
 200static void gcm_hash_len_done(struct crypto_async_request *areq, int err);
 201
 202static int gcm_hash_update(struct aead_request *req,
 203                           crypto_completion_t compl,
 204                           struct scatterlist *src,
 205                           unsigned int len, u32 flags)
 206{
 207        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 208        struct ahash_request *ahreq = &pctx->u.ahreq;
 209
 210        ahash_request_set_callback(ahreq, flags, compl, req);
 211        ahash_request_set_crypt(ahreq, src, NULL, len);
 212
 213        return crypto_ahash_update(ahreq);
 214}
 215
 216static int gcm_hash_remain(struct aead_request *req,
 217                           unsigned int remain,
 218                           crypto_completion_t compl, u32 flags)
 219{
 220        return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags);
 221}
 222
 223static int gcm_hash_len(struct aead_request *req, u32 flags)
 224{
 225        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 226        struct ahash_request *ahreq = &pctx->u.ahreq;
 227        struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 228        be128 lengths;
 229
 230        lengths.a = cpu_to_be64(req->assoclen * 8);
 231        lengths.b = cpu_to_be64(gctx->cryptlen * 8);
 232        memcpy(pctx->iauth_tag, &lengths, 16);
 233        sg_init_one(&pctx->sg, pctx->iauth_tag, 16);
 234        ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req);
 235        ahash_request_set_crypt(ahreq, &pctx->sg,
 236                                pctx->iauth_tag, sizeof(lengths));
 237
 238        return crypto_ahash_finup(ahreq);
 239}
 240
 241static int gcm_hash_len_continue(struct aead_request *req, u32 flags)
 242{
 243        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 244        struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 245
 246        return gctx->complete(req, flags);
 247}
 248
 249static void gcm_hash_len_done(struct crypto_async_request *areq, int err)
 250{
 251        struct aead_request *req = areq->data;
 252
 253        if (err)
 254                goto out;
 255
 256        err = gcm_hash_len_continue(req, 0);
 257        if (err == -EINPROGRESS)
 258                return;
 259
 260out:
 261        aead_request_complete(req, err);
 262}
 263
 264static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags)
 265{
 266        return gcm_hash_len(req, flags) ?:
 267               gcm_hash_len_continue(req, flags);
 268}
 269
 270static void gcm_hash_crypt_remain_done(struct crypto_async_request *areq,
 271                                       int err)
 272{
 273        struct aead_request *req = areq->data;
 274
 275        if (err)
 276                goto out;
 277
 278        err = gcm_hash_crypt_remain_continue(req, 0);
 279        if (err == -EINPROGRESS)
 280                return;
 281
 282out:
 283        aead_request_complete(req, err);
 284}
 285
 286static int gcm_hash_crypt_continue(struct aead_request *req, u32 flags)
 287{
 288        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 289        struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 290        unsigned int remain;
 291
 292        remain = gcm_remain(gctx->cryptlen);
 293        if (remain)
 294                return gcm_hash_remain(req, remain,
 295                                       gcm_hash_crypt_remain_done, flags) ?:
 296                       gcm_hash_crypt_remain_continue(req, flags);
 297
 298        return gcm_hash_crypt_remain_continue(req, flags);
 299}
 300
 301static void gcm_hash_crypt_done(struct crypto_async_request *areq, int err)
 302{
 303        struct aead_request *req = areq->data;
 304
 305        if (err)
 306                goto out;
 307
 308        err = gcm_hash_crypt_continue(req, 0);
 309        if (err == -EINPROGRESS)
 310                return;
 311
 312out:
 313        aead_request_complete(req, err);
 314}
 315
 316static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags)
 317{
 318        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 319        struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 320
 321        if (gctx->cryptlen)
 322                return gcm_hash_update(req, gcm_hash_crypt_done,
 323                                       gctx->src, gctx->cryptlen, flags) ?:
 324                       gcm_hash_crypt_continue(req, flags);
 325
 326        return gcm_hash_crypt_remain_continue(req, flags);
 327}
 328
 329static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq,
 330                                       int err)
 331{
 332        struct aead_request *req = areq->data;
 333
 334        if (err)
 335                goto out;
 336
 337        err = gcm_hash_assoc_remain_continue(req, 0);
 338        if (err == -EINPROGRESS)
 339                return;
 340
 341out:
 342        aead_request_complete(req, err);
 343}
 344
 345static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags)
 346{
 347        unsigned int remain;
 348
 349        remain = gcm_remain(req->assoclen);
 350        if (remain)
 351                return gcm_hash_remain(req, remain,
 352                                       gcm_hash_assoc_remain_done, flags) ?:
 353                       gcm_hash_assoc_remain_continue(req, flags);
 354
 355        return gcm_hash_assoc_remain_continue(req, flags);
 356}
 357
 358static void gcm_hash_assoc_done(struct crypto_async_request *areq, int err)
 359{
 360        struct aead_request *req = areq->data;
 361
 362        if (err)
 363                goto out;
 364
 365        err = gcm_hash_assoc_continue(req, 0);
 366        if (err == -EINPROGRESS)
 367                return;
 368
 369out:
 370        aead_request_complete(req, err);
 371}
 372
 373static int gcm_hash_init_continue(struct aead_request *req, u32 flags)
 374{
 375        if (req->assoclen)
 376                return gcm_hash_update(req, gcm_hash_assoc_done,
 377                                       req->src, req->assoclen, flags) ?:
 378                       gcm_hash_assoc_continue(req, flags);
 379
 380        return gcm_hash_assoc_remain_continue(req, flags);
 381}
 382
 383static void gcm_hash_init_done(struct crypto_async_request *areq, int err)
 384{
 385        struct aead_request *req = areq->data;
 386
 387        if (err)
 388                goto out;
 389
 390        err = gcm_hash_init_continue(req, 0);
 391        if (err == -EINPROGRESS)
 392                return;
 393
 394out:
 395        aead_request_complete(req, err);
 396}
 397
 398static int gcm_hash(struct aead_request *req, u32 flags)
 399{
 400        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 401        struct ahash_request *ahreq = &pctx->u.ahreq;
 402        struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 403
 404        ahash_request_set_tfm(ahreq, ctx->ghash);
 405
 406        ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req);
 407        return crypto_ahash_init(ahreq) ?:
 408               gcm_hash_init_continue(req, flags);
 409}
 410
 411static int gcm_enc_copy_hash(struct aead_request *req, u32 flags)
 412{
 413        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 414        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 415        u8 *auth_tag = pctx->auth_tag;
 416
 417        crypto_xor(auth_tag, pctx->iauth_tag, 16);
 418        scatterwalk_map_and_copy(auth_tag, req->dst,
 419                                 req->assoclen + req->cryptlen,
 420                                 crypto_aead_authsize(aead), 1);
 421        return 0;
 422}
 423
 424static int gcm_encrypt_continue(struct aead_request *req, u32 flags)
 425{
 426        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 427        struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 428
 429        gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
 430        gctx->cryptlen = req->cryptlen;
 431        gctx->complete = gcm_enc_copy_hash;
 432
 433        return gcm_hash(req, flags);
 434}
 435
 436static void gcm_encrypt_done(struct crypto_async_request *areq, int err)
 437{
 438        struct aead_request *req = areq->data;
 439
 440        if (err)
 441                goto out;
 442
 443        err = gcm_encrypt_continue(req, 0);
 444        if (err == -EINPROGRESS)
 445                return;
 446
 447out:
 448        aead_request_complete(req, err);
 449}
 450
 451static int crypto_gcm_encrypt(struct aead_request *req)
 452{
 453        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 454        struct skcipher_request *skreq = &pctx->u.skreq;
 455        u32 flags = aead_request_flags(req);
 456
 457        crypto_gcm_init_common(req);
 458        crypto_gcm_init_crypt(req, req->cryptlen);
 459        skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req);
 460
 461        return crypto_skcipher_encrypt(skreq) ?:
 462               gcm_encrypt_continue(req, flags);
 463}
 464
 465static int crypto_gcm_verify(struct aead_request *req)
 466{
 467        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 468        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 469        u8 *auth_tag = pctx->auth_tag;
 470        u8 *iauth_tag = pctx->iauth_tag;
 471        unsigned int authsize = crypto_aead_authsize(aead);
 472        unsigned int cryptlen = req->cryptlen - authsize;
 473
 474        crypto_xor(auth_tag, iauth_tag, 16);
 475        scatterwalk_map_and_copy(iauth_tag, req->src,
 476                                 req->assoclen + cryptlen, authsize, 0);
 477        return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
 478}
 479
 480static void gcm_decrypt_done(struct crypto_async_request *areq, int err)
 481{
 482        struct aead_request *req = areq->data;
 483
 484        if (!err)
 485                err = crypto_gcm_verify(req);
 486
 487        aead_request_complete(req, err);
 488}
 489
 490static int gcm_dec_hash_continue(struct aead_request *req, u32 flags)
 491{
 492        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 493        struct skcipher_request *skreq = &pctx->u.skreq;
 494        struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 495
 496        crypto_gcm_init_crypt(req, gctx->cryptlen);
 497        skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req);
 498        return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req);
 499}
 500
 501static int crypto_gcm_decrypt(struct aead_request *req)
 502{
 503        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 504        struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 505        struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 506        unsigned int authsize = crypto_aead_authsize(aead);
 507        unsigned int cryptlen = req->cryptlen;
 508        u32 flags = aead_request_flags(req);
 509
 510        cryptlen -= authsize;
 511
 512        crypto_gcm_init_common(req);
 513
 514        gctx->src = sg_next(pctx->src);
 515        gctx->cryptlen = cryptlen;
 516        gctx->complete = gcm_dec_hash_continue;
 517
 518        return gcm_hash(req, flags);
 519}
 520
 521static int crypto_gcm_init_tfm(struct crypto_aead *tfm)
 522{
 523        struct aead_instance *inst = aead_alg_instance(tfm);
 524        struct gcm_instance_ctx *ictx = aead_instance_ctx(inst);
 525        struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 526        struct crypto_skcipher *ctr;
 527        struct crypto_ahash *ghash;
 528        unsigned long align;
 529        int err;
 530
 531        ghash = crypto_spawn_ahash(&ictx->ghash);
 532        if (IS_ERR(ghash))
 533                return PTR_ERR(ghash);
 534
 535        ctr = crypto_spawn_skcipher(&ictx->ctr);
 536        err = PTR_ERR(ctr);
 537        if (IS_ERR(ctr))
 538                goto err_free_hash;
 539
 540        ctx->ctr = ctr;
 541        ctx->ghash = ghash;
 542
 543        align = crypto_aead_alignmask(tfm);
 544        align &= ~(crypto_tfm_ctx_alignment() - 1);
 545        crypto_aead_set_reqsize(tfm,
 546                align + offsetof(struct crypto_gcm_req_priv_ctx, u) +
 547                max(sizeof(struct skcipher_request) +
 548                    crypto_skcipher_reqsize(ctr),
 549                    sizeof(struct ahash_request) +
 550                    crypto_ahash_reqsize(ghash)));
 551
 552        return 0;
 553
 554err_free_hash:
 555        crypto_free_ahash(ghash);
 556        return err;
 557}
 558
 559static void crypto_gcm_exit_tfm(struct crypto_aead *tfm)
 560{
 561        struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 562
 563        crypto_free_ahash(ctx->ghash);
 564        crypto_free_skcipher(ctx->ctr);
 565}
 566
 567static void crypto_gcm_free(struct aead_instance *inst)
 568{
 569        struct gcm_instance_ctx *ctx = aead_instance_ctx(inst);
 570
 571        crypto_drop_skcipher(&ctx->ctr);
 572        crypto_drop_ahash(&ctx->ghash);
 573        kfree(inst);
 574}
 575
 576static int crypto_gcm_create_common(struct crypto_template *tmpl,
 577                                    struct rtattr **tb,
 578                                    const char *ctr_name,
 579                                    const char *ghash_name)
 580{
 581        u32 mask;
 582        struct aead_instance *inst;
 583        struct gcm_instance_ctx *ctx;
 584        struct skcipher_alg *ctr;
 585        struct hash_alg_common *ghash;
 586        int err;
 587
 588        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 589        if (err)
 590                return err;
 591
 592        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 593        if (!inst)
 594                return -ENOMEM;
 595        ctx = aead_instance_ctx(inst);
 596
 597        err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst),
 598                                ghash_name, 0, mask);
 599        if (err)
 600                goto err_free_inst;
 601        ghash = crypto_spawn_ahash_alg(&ctx->ghash);
 602
 603        err = -EINVAL;
 604        if (strcmp(ghash->base.cra_name, "ghash") != 0 ||
 605            ghash->digestsize != 16)
 606                goto err_free_inst;
 607
 608        err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst),
 609                                   ctr_name, 0, mask);
 610        if (err)
 611                goto err_free_inst;
 612        ctr = crypto_spawn_skcipher_alg(&ctx->ctr);
 613
 614        /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
 615        err = -EINVAL;
 616        if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
 617            crypto_skcipher_alg_ivsize(ctr) != 16 ||
 618            ctr->base.cra_blocksize != 1)
 619                goto err_free_inst;
 620
 621        err = -ENAMETOOLONG;
 622        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 623                     "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
 624                goto err_free_inst;
 625
 626        if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 627                     "gcm_base(%s,%s)", ctr->base.cra_driver_name,
 628                     ghash->base.cra_driver_name) >=
 629            CRYPTO_MAX_ALG_NAME)
 630                goto err_free_inst;
 631
 632        inst->alg.base.cra_priority = (ghash->base.cra_priority +
 633                                       ctr->base.cra_priority) / 2;
 634        inst->alg.base.cra_blocksize = 1;
 635        inst->alg.base.cra_alignmask = ghash->base.cra_alignmask |
 636                                       ctr->base.cra_alignmask;
 637        inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
 638        inst->alg.ivsize = GCM_AES_IV_SIZE;
 639        inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
 640        inst->alg.maxauthsize = 16;
 641        inst->alg.init = crypto_gcm_init_tfm;
 642        inst->alg.exit = crypto_gcm_exit_tfm;
 643        inst->alg.setkey = crypto_gcm_setkey;
 644        inst->alg.setauthsize = crypto_gcm_setauthsize;
 645        inst->alg.encrypt = crypto_gcm_encrypt;
 646        inst->alg.decrypt = crypto_gcm_decrypt;
 647
 648        inst->free = crypto_gcm_free;
 649
 650        err = aead_register_instance(tmpl, inst);
 651        if (err) {
 652err_free_inst:
 653                crypto_gcm_free(inst);
 654        }
 655        return err;
 656}
 657
 658static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)
 659{
 660        const char *cipher_name;
 661        char ctr_name[CRYPTO_MAX_ALG_NAME];
 662
 663        cipher_name = crypto_attr_alg_name(tb[1]);
 664        if (IS_ERR(cipher_name))
 665                return PTR_ERR(cipher_name);
 666
 667        if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
 668            CRYPTO_MAX_ALG_NAME)
 669                return -ENAMETOOLONG;
 670
 671        return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash");
 672}
 673
 674static int crypto_gcm_base_create(struct crypto_template *tmpl,
 675                                  struct rtattr **tb)
 676{
 677        const char *ctr_name;
 678        const char *ghash_name;
 679
 680        ctr_name = crypto_attr_alg_name(tb[1]);
 681        if (IS_ERR(ctr_name))
 682                return PTR_ERR(ctr_name);
 683
 684        ghash_name = crypto_attr_alg_name(tb[2]);
 685        if (IS_ERR(ghash_name))
 686                return PTR_ERR(ghash_name);
 687
 688        return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name);
 689}
 690
 691static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
 692                                 unsigned int keylen)
 693{
 694        struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 695        struct crypto_aead *child = ctx->child;
 696
 697        if (keylen < 4)
 698                return -EINVAL;
 699
 700        keylen -= 4;
 701        memcpy(ctx->nonce, key + keylen, 4);
 702
 703        crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 704        crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 705                                     CRYPTO_TFM_REQ_MASK);
 706        return crypto_aead_setkey(child, key, keylen);
 707}
 708
 709static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
 710                                      unsigned int authsize)
 711{
 712        struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
 713        int err;
 714
 715        err = crypto_rfc4106_check_authsize(authsize);
 716        if (err)
 717                return err;
 718
 719        return crypto_aead_setauthsize(ctx->child, authsize);
 720}
 721
 722static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
 723{
 724        struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req);
 725        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 726        struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
 727        struct aead_request *subreq = &rctx->subreq;
 728        struct crypto_aead *child = ctx->child;
 729        struct scatterlist *sg;
 730        u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
 731                           crypto_aead_alignmask(child) + 1);
 732
 733        scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0);
 734
 735        memcpy(iv, ctx->nonce, 4);
 736        memcpy(iv + 4, req->iv, 8);
 737
 738        sg_init_table(rctx->src, 3);
 739        sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
 740        sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
 741        if (sg != rctx->src + 1)
 742                sg_chain(rctx->src, 2, sg);
 743
 744        if (req->src != req->dst) {
 745                sg_init_table(rctx->dst, 3);
 746                sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
 747                sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
 748                if (sg != rctx->dst + 1)
 749                        sg_chain(rctx->dst, 2, sg);
 750        }
 751
 752        aead_request_set_tfm(subreq, child);
 753        aead_request_set_callback(subreq, req->base.flags, req->base.complete,
 754                                  req->base.data);
 755        aead_request_set_crypt(subreq, rctx->src,
 756                               req->src == req->dst ? rctx->src : rctx->dst,
 757                               req->cryptlen, iv);
 758        aead_request_set_ad(subreq, req->assoclen - 8);
 759
 760        return subreq;
 761}
 762
 763static int crypto_rfc4106_encrypt(struct aead_request *req)
 764{
 765        int err;
 766
 767        err = crypto_ipsec_check_assoclen(req->assoclen);
 768        if (err)
 769                return err;
 770
 771        req = crypto_rfc4106_crypt(req);
 772
 773        return crypto_aead_encrypt(req);
 774}
 775
 776static int crypto_rfc4106_decrypt(struct aead_request *req)
 777{
 778        int err;
 779
 780        err = crypto_ipsec_check_assoclen(req->assoclen);
 781        if (err)
 782                return err;
 783
 784        req = crypto_rfc4106_crypt(req);
 785
 786        return crypto_aead_decrypt(req);
 787}
 788
 789static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm)
 790{
 791        struct aead_instance *inst = aead_alg_instance(tfm);
 792        struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
 793        struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
 794        struct crypto_aead *aead;
 795        unsigned long align;
 796
 797        aead = crypto_spawn_aead(spawn);
 798        if (IS_ERR(aead))
 799                return PTR_ERR(aead);
 800
 801        ctx->child = aead;
 802
 803        align = crypto_aead_alignmask(aead);
 804        align &= ~(crypto_tfm_ctx_alignment() - 1);
 805        crypto_aead_set_reqsize(
 806                tfm,
 807                sizeof(struct crypto_rfc4106_req_ctx) +
 808                ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
 809                align + 24);
 810
 811        return 0;
 812}
 813
 814static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm)
 815{
 816        struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
 817
 818        crypto_free_aead(ctx->child);
 819}
 820
 821static void crypto_rfc4106_free(struct aead_instance *inst)
 822{
 823        crypto_drop_aead(aead_instance_ctx(inst));
 824        kfree(inst);
 825}
 826
 827static int crypto_rfc4106_create(struct crypto_template *tmpl,
 828                                 struct rtattr **tb)
 829{
 830        u32 mask;
 831        struct aead_instance *inst;
 832        struct crypto_aead_spawn *spawn;
 833        struct aead_alg *alg;
 834        int err;
 835
 836        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
 837        if (err)
 838                return err;
 839
 840        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 841        if (!inst)
 842                return -ENOMEM;
 843
 844        spawn = aead_instance_ctx(inst);
 845        err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
 846                               crypto_attr_alg_name(tb[1]), 0, mask);
 847        if (err)
 848                goto err_free_inst;
 849
 850        alg = crypto_spawn_aead_alg(spawn);
 851
 852        err = -EINVAL;
 853
 854        /* Underlying IV size must be 12. */
 855        if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
 856                goto err_free_inst;
 857
 858        /* Not a stream cipher? */
 859        if (alg->base.cra_blocksize != 1)
 860                goto err_free_inst;
 861
 862        err = -ENAMETOOLONG;
 863        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 864                     "rfc4106(%s)", alg->base.cra_name) >=
 865            CRYPTO_MAX_ALG_NAME ||
 866            snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 867                     "rfc4106(%s)", alg->base.cra_driver_name) >=
 868            CRYPTO_MAX_ALG_NAME)
 869                goto err_free_inst;
 870
 871        inst->alg.base.cra_priority = alg->base.cra_priority;
 872        inst->alg.base.cra_blocksize = 1;
 873        inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 874
 875        inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
 876
 877        inst->alg.ivsize = GCM_RFC4106_IV_SIZE;
 878        inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
 879        inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
 880
 881        inst->alg.init = crypto_rfc4106_init_tfm;
 882        inst->alg.exit = crypto_rfc4106_exit_tfm;
 883
 884        inst->alg.setkey = crypto_rfc4106_setkey;
 885        inst->alg.setauthsize = crypto_rfc4106_setauthsize;
 886        inst->alg.encrypt = crypto_rfc4106_encrypt;
 887        inst->alg.decrypt = crypto_rfc4106_decrypt;
 888
 889        inst->free = crypto_rfc4106_free;
 890
 891        err = aead_register_instance(tmpl, inst);
 892        if (err) {
 893err_free_inst:
 894                crypto_rfc4106_free(inst);
 895        }
 896        return err;
 897}
 898
 899static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
 900                                 unsigned int keylen)
 901{
 902        struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
 903        struct crypto_aead *child = ctx->child;
 904
 905        if (keylen < 4)
 906                return -EINVAL;
 907
 908        keylen -= 4;
 909        memcpy(ctx->nonce, key + keylen, 4);
 910
 911        crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 912        crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
 913                                     CRYPTO_TFM_REQ_MASK);
 914        return crypto_aead_setkey(child, key, keylen);
 915}
 916
 917static int crypto_rfc4543_setauthsize(struct crypto_aead *parent,
 918                                      unsigned int authsize)
 919{
 920        struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
 921
 922        if (authsize != 16)
 923                return -EINVAL;
 924
 925        return crypto_aead_setauthsize(ctx->child, authsize);
 926}
 927
 928static int crypto_rfc4543_crypt(struct aead_request *req, bool enc)
 929{
 930        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 931        struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
 932        struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req);
 933        struct aead_request *subreq = &rctx->subreq;
 934        unsigned int authsize = crypto_aead_authsize(aead);
 935        u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
 936                           crypto_aead_alignmask(ctx->child) + 1);
 937        int err;
 938
 939        if (req->src != req->dst) {
 940                err = crypto_rfc4543_copy_src_to_dst(req, enc);
 941                if (err)
 942                        return err;
 943        }
 944
 945        memcpy(iv, ctx->nonce, 4);
 946        memcpy(iv + 4, req->iv, 8);
 947
 948        aead_request_set_tfm(subreq, ctx->child);
 949        aead_request_set_callback(subreq, req->base.flags,
 950                                  req->base.complete, req->base.data);
 951        aead_request_set_crypt(subreq, req->src, req->dst,
 952                               enc ? 0 : authsize, iv);
 953        aead_request_set_ad(subreq, req->assoclen + req->cryptlen -
 954                                    subreq->cryptlen);
 955
 956        return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq);
 957}
 958
 959static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
 960{
 961        struct crypto_aead *aead = crypto_aead_reqtfm(req);
 962        struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
 963        unsigned int authsize = crypto_aead_authsize(aead);
 964        unsigned int nbytes = req->assoclen + req->cryptlen -
 965                              (enc ? 0 : authsize);
 966        SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null);
 967
 968        skcipher_request_set_sync_tfm(nreq, ctx->null);
 969        skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL);
 970        skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL);
 971
 972        return crypto_skcipher_encrypt(nreq);
 973}
 974
 975static int crypto_rfc4543_encrypt(struct aead_request *req)
 976{
 977        return crypto_ipsec_check_assoclen(req->assoclen) ?:
 978               crypto_rfc4543_crypt(req, true);
 979}
 980
 981static int crypto_rfc4543_decrypt(struct aead_request *req)
 982{
 983        return crypto_ipsec_check_assoclen(req->assoclen) ?:
 984               crypto_rfc4543_crypt(req, false);
 985}
 986
 987static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
 988{
 989        struct aead_instance *inst = aead_alg_instance(tfm);
 990        struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst);
 991        struct crypto_aead_spawn *spawn = &ictx->aead;
 992        struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
 993        struct crypto_aead *aead;
 994        struct crypto_sync_skcipher *null;
 995        unsigned long align;
 996        int err = 0;
 997
 998        aead = crypto_spawn_aead(spawn);
 999        if (IS_ERR(aead))
1000                return PTR_ERR(aead);
1001
1002        null = crypto_get_default_null_skcipher();
1003        err = PTR_ERR(null);
1004        if (IS_ERR(null))
1005                goto err_free_aead;
1006
1007        ctx->child = aead;
1008        ctx->null = null;
1009
1010        align = crypto_aead_alignmask(aead);
1011        align &= ~(crypto_tfm_ctx_alignment() - 1);
1012        crypto_aead_set_reqsize(
1013                tfm,
1014                sizeof(struct crypto_rfc4543_req_ctx) +
1015                ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
1016                align + GCM_AES_IV_SIZE);
1017
1018        return 0;
1019
1020err_free_aead:
1021        crypto_free_aead(aead);
1022        return err;
1023}
1024
1025static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm)
1026{
1027        struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
1028
1029        crypto_free_aead(ctx->child);
1030        crypto_put_default_null_skcipher();
1031}
1032
1033static void crypto_rfc4543_free(struct aead_instance *inst)
1034{
1035        struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst);
1036
1037        crypto_drop_aead(&ctx->aead);
1038
1039        kfree(inst);
1040}
1041
1042static int crypto_rfc4543_create(struct crypto_template *tmpl,
1043                                struct rtattr **tb)
1044{
1045        u32 mask;
1046        struct aead_instance *inst;
1047        struct aead_alg *alg;
1048        struct crypto_rfc4543_instance_ctx *ctx;
1049        int err;
1050
1051        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
1052        if (err)
1053                return err;
1054
1055        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
1056        if (!inst)
1057                return -ENOMEM;
1058
1059        ctx = aead_instance_ctx(inst);
1060        err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst),
1061                               crypto_attr_alg_name(tb[1]), 0, mask);
1062        if (err)
1063                goto err_free_inst;
1064
1065        alg = crypto_spawn_aead_alg(&ctx->aead);
1066
1067        err = -EINVAL;
1068
1069        /* Underlying IV size must be 12. */
1070        if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
1071                goto err_free_inst;
1072
1073        /* Not a stream cipher? */
1074        if (alg->base.cra_blocksize != 1)
1075                goto err_free_inst;
1076
1077        err = -ENAMETOOLONG;
1078        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
1079                     "rfc4543(%s)", alg->base.cra_name) >=
1080            CRYPTO_MAX_ALG_NAME ||
1081            snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
1082                     "rfc4543(%s)", alg->base.cra_driver_name) >=
1083            CRYPTO_MAX_ALG_NAME)
1084                goto err_free_inst;
1085
1086        inst->alg.base.cra_priority = alg->base.cra_priority;
1087        inst->alg.base.cra_blocksize = 1;
1088        inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
1089
1090        inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx);
1091
1092        inst->alg.ivsize = GCM_RFC4543_IV_SIZE;
1093        inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
1094        inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
1095
1096        inst->alg.init = crypto_rfc4543_init_tfm;
1097        inst->alg.exit = crypto_rfc4543_exit_tfm;
1098
1099        inst->alg.setkey = crypto_rfc4543_setkey;
1100        inst->alg.setauthsize = crypto_rfc4543_setauthsize;
1101        inst->alg.encrypt = crypto_rfc4543_encrypt;
1102        inst->alg.decrypt = crypto_rfc4543_decrypt;
1103
1104        inst->free = crypto_rfc4543_free;
1105
1106        err = aead_register_instance(tmpl, inst);
1107        if (err) {
1108err_free_inst:
1109                crypto_rfc4543_free(inst);
1110        }
1111        return err;
1112}
1113
1114static struct crypto_template crypto_gcm_tmpls[] = {
1115        {
1116                .name = "gcm_base",
1117                .create = crypto_gcm_base_create,
1118                .module = THIS_MODULE,
1119        }, {
1120                .name = "gcm",
1121                .create = crypto_gcm_create,
1122                .module = THIS_MODULE,
1123        }, {
1124                .name = "rfc4106",
1125                .create = crypto_rfc4106_create,
1126                .module = THIS_MODULE,
1127        }, {
1128                .name = "rfc4543",
1129                .create = crypto_rfc4543_create,
1130                .module = THIS_MODULE,
1131        },
1132};
1133
1134static int __init crypto_gcm_module_init(void)
1135{
1136        int err;
1137
1138        gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL);
1139        if (!gcm_zeroes)
1140                return -ENOMEM;
1141
1142        sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf));
1143
1144        err = crypto_register_templates(crypto_gcm_tmpls,
1145                                        ARRAY_SIZE(crypto_gcm_tmpls));
1146        if (err)
1147                kfree(gcm_zeroes);
1148
1149        return err;
1150}
1151
1152static void __exit crypto_gcm_module_exit(void)
1153{
1154        kfree(gcm_zeroes);
1155        crypto_unregister_templates(crypto_gcm_tmpls,
1156                                    ARRAY_SIZE(crypto_gcm_tmpls));
1157}
1158
1159subsys_initcall(crypto_gcm_module_init);
1160module_exit(crypto_gcm_module_exit);
1161
1162MODULE_LICENSE("GPL");
1163MODULE_DESCRIPTION("Galois/Counter Mode");
1164MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1165MODULE_ALIAS_CRYPTO("gcm_base");
1166MODULE_ALIAS_CRYPTO("rfc4106");
1167MODULE_ALIAS_CRYPTO("rfc4543");
1168MODULE_ALIAS_CRYPTO("gcm");
1169
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