linux/crypto/chacha20poly1305.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * ChaCha20-Poly1305 AEAD, RFC7539
   4 *
   5 * Copyright (C) 2015 Martin Willi
   6 */
   7
   8#include <crypto/internal/aead.h>
   9#include <crypto/internal/hash.h>
  10#include <crypto/internal/skcipher.h>
  11#include <crypto/scatterwalk.h>
  12#include <crypto/chacha.h>
  13#include <crypto/poly1305.h>
  14#include <linux/err.h>
  15#include <linux/init.h>
  16#include <linux/kernel.h>
  17#include <linux/module.h>
  18
  19#include "internal.h"
  20
  21struct chachapoly_instance_ctx {
  22        struct crypto_skcipher_spawn chacha;
  23        struct crypto_ahash_spawn poly;
  24        unsigned int saltlen;
  25};
  26
  27struct chachapoly_ctx {
  28        struct crypto_skcipher *chacha;
  29        struct crypto_ahash *poly;
  30        /* key bytes we use for the ChaCha20 IV */
  31        unsigned int saltlen;
  32        u8 salt[];
  33};
  34
  35struct poly_req {
  36        /* zero byte padding for AD/ciphertext, as needed */
  37        u8 pad[POLY1305_BLOCK_SIZE];
  38        /* tail data with AD/ciphertext lengths */
  39        struct {
  40                __le64 assoclen;
  41                __le64 cryptlen;
  42        } tail;
  43        struct scatterlist src[1];
  44        struct ahash_request req; /* must be last member */
  45};
  46
  47struct chacha_req {
  48        u8 iv[CHACHA_IV_SIZE];
  49        struct scatterlist src[1];
  50        struct skcipher_request req; /* must be last member */
  51};
  52
  53struct chachapoly_req_ctx {
  54        struct scatterlist src[2];
  55        struct scatterlist dst[2];
  56        /* the key we generate for Poly1305 using Chacha20 */
  57        u8 key[POLY1305_KEY_SIZE];
  58        /* calculated Poly1305 tag */
  59        u8 tag[POLY1305_DIGEST_SIZE];
  60        /* length of data to en/decrypt, without ICV */
  61        unsigned int cryptlen;
  62        /* Actual AD, excluding IV */
  63        unsigned int assoclen;
  64        /* request flags, with MAY_SLEEP cleared if needed */
  65        u32 flags;
  66        union {
  67                struct poly_req poly;
  68                struct chacha_req chacha;
  69        } u;
  70};
  71
  72static inline void async_done_continue(struct aead_request *req, int err,
  73                                       int (*cont)(struct aead_request *))
  74{
  75        if (!err) {
  76                struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
  77
  78                rctx->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
  79                err = cont(req);
  80        }
  81
  82        if (err != -EINPROGRESS && err != -EBUSY)
  83                aead_request_complete(req, err);
  84}
  85
  86static void chacha_iv(u8 *iv, struct aead_request *req, u32 icb)
  87{
  88        struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
  89        __le32 leicb = cpu_to_le32(icb);
  90
  91        memcpy(iv, &leicb, sizeof(leicb));
  92        memcpy(iv + sizeof(leicb), ctx->salt, ctx->saltlen);
  93        memcpy(iv + sizeof(leicb) + ctx->saltlen, req->iv,
  94               CHACHA_IV_SIZE - sizeof(leicb) - ctx->saltlen);
  95}
  96
  97static int poly_verify_tag(struct aead_request *req)
  98{
  99        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 100        u8 tag[sizeof(rctx->tag)];
 101
 102        scatterwalk_map_and_copy(tag, req->src,
 103                                 req->assoclen + rctx->cryptlen,
 104                                 sizeof(tag), 0);
 105        if (crypto_memneq(tag, rctx->tag, sizeof(tag)))
 106                return -EBADMSG;
 107        return 0;
 108}
 109
 110static int poly_copy_tag(struct aead_request *req)
 111{
 112        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 113
 114        scatterwalk_map_and_copy(rctx->tag, req->dst,
 115                                 req->assoclen + rctx->cryptlen,
 116                                 sizeof(rctx->tag), 1);
 117        return 0;
 118}
 119
 120static void chacha_decrypt_done(struct crypto_async_request *areq, int err)
 121{
 122        async_done_continue(areq->data, err, poly_verify_tag);
 123}
 124
 125static int chacha_decrypt(struct aead_request *req)
 126{
 127        struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 128        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 129        struct chacha_req *creq = &rctx->u.chacha;
 130        struct scatterlist *src, *dst;
 131        int err;
 132
 133        if (rctx->cryptlen == 0)
 134                goto skip;
 135
 136        chacha_iv(creq->iv, req, 1);
 137
 138        src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
 139        dst = src;
 140        if (req->src != req->dst)
 141                dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
 142
 143        skcipher_request_set_callback(&creq->req, rctx->flags,
 144                                      chacha_decrypt_done, req);
 145        skcipher_request_set_tfm(&creq->req, ctx->chacha);
 146        skcipher_request_set_crypt(&creq->req, src, dst,
 147                                   rctx->cryptlen, creq->iv);
 148        err = crypto_skcipher_decrypt(&creq->req);
 149        if (err)
 150                return err;
 151
 152skip:
 153        return poly_verify_tag(req);
 154}
 155
 156static int poly_tail_continue(struct aead_request *req)
 157{
 158        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 159
 160        if (rctx->cryptlen == req->cryptlen) /* encrypting */
 161                return poly_copy_tag(req);
 162
 163        return chacha_decrypt(req);
 164}
 165
 166static void poly_tail_done(struct crypto_async_request *areq, int err)
 167{
 168        async_done_continue(areq->data, err, poly_tail_continue);
 169}
 170
 171static int poly_tail(struct aead_request *req)
 172{
 173        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 174        struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
 175        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 176        struct poly_req *preq = &rctx->u.poly;
 177        int err;
 178
 179        preq->tail.assoclen = cpu_to_le64(rctx->assoclen);
 180        preq->tail.cryptlen = cpu_to_le64(rctx->cryptlen);
 181        sg_init_one(preq->src, &preq->tail, sizeof(preq->tail));
 182
 183        ahash_request_set_callback(&preq->req, rctx->flags,
 184                                   poly_tail_done, req);
 185        ahash_request_set_tfm(&preq->req, ctx->poly);
 186        ahash_request_set_crypt(&preq->req, preq->src,
 187                                rctx->tag, sizeof(preq->tail));
 188
 189        err = crypto_ahash_finup(&preq->req);
 190        if (err)
 191                return err;
 192
 193        return poly_tail_continue(req);
 194}
 195
 196static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
 197{
 198        async_done_continue(areq->data, err, poly_tail);
 199}
 200
 201static int poly_cipherpad(struct aead_request *req)
 202{
 203        struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 204        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 205        struct poly_req *preq = &rctx->u.poly;
 206        unsigned int padlen;
 207        int err;
 208
 209        padlen = -rctx->cryptlen % POLY1305_BLOCK_SIZE;
 210        memset(preq->pad, 0, sizeof(preq->pad));
 211        sg_init_one(preq->src, preq->pad, padlen);
 212
 213        ahash_request_set_callback(&preq->req, rctx->flags,
 214                                   poly_cipherpad_done, req);
 215        ahash_request_set_tfm(&preq->req, ctx->poly);
 216        ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
 217
 218        err = crypto_ahash_update(&preq->req);
 219        if (err)
 220                return err;
 221
 222        return poly_tail(req);
 223}
 224
 225static void poly_cipher_done(struct crypto_async_request *areq, int err)
 226{
 227        async_done_continue(areq->data, err, poly_cipherpad);
 228}
 229
 230static int poly_cipher(struct aead_request *req)
 231{
 232        struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 233        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 234        struct poly_req *preq = &rctx->u.poly;
 235        struct scatterlist *crypt = req->src;
 236        int err;
 237
 238        if (rctx->cryptlen == req->cryptlen) /* encrypting */
 239                crypt = req->dst;
 240
 241        crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen);
 242
 243        ahash_request_set_callback(&preq->req, rctx->flags,
 244                                   poly_cipher_done, req);
 245        ahash_request_set_tfm(&preq->req, ctx->poly);
 246        ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen);
 247
 248        err = crypto_ahash_update(&preq->req);
 249        if (err)
 250                return err;
 251
 252        return poly_cipherpad(req);
 253}
 254
 255static void poly_adpad_done(struct crypto_async_request *areq, int err)
 256{
 257        async_done_continue(areq->data, err, poly_cipher);
 258}
 259
 260static int poly_adpad(struct aead_request *req)
 261{
 262        struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 263        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 264        struct poly_req *preq = &rctx->u.poly;
 265        unsigned int padlen;
 266        int err;
 267
 268        padlen = -rctx->assoclen % POLY1305_BLOCK_SIZE;
 269        memset(preq->pad, 0, sizeof(preq->pad));
 270        sg_init_one(preq->src, preq->pad, padlen);
 271
 272        ahash_request_set_callback(&preq->req, rctx->flags,
 273                                   poly_adpad_done, req);
 274        ahash_request_set_tfm(&preq->req, ctx->poly);
 275        ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
 276
 277        err = crypto_ahash_update(&preq->req);
 278        if (err)
 279                return err;
 280
 281        return poly_cipher(req);
 282}
 283
 284static void poly_ad_done(struct crypto_async_request *areq, int err)
 285{
 286        async_done_continue(areq->data, err, poly_adpad);
 287}
 288
 289static int poly_ad(struct aead_request *req)
 290{
 291        struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 292        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 293        struct poly_req *preq = &rctx->u.poly;
 294        int err;
 295
 296        ahash_request_set_callback(&preq->req, rctx->flags,
 297                                   poly_ad_done, req);
 298        ahash_request_set_tfm(&preq->req, ctx->poly);
 299        ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen);
 300
 301        err = crypto_ahash_update(&preq->req);
 302        if (err)
 303                return err;
 304
 305        return poly_adpad(req);
 306}
 307
 308static void poly_setkey_done(struct crypto_async_request *areq, int err)
 309{
 310        async_done_continue(areq->data, err, poly_ad);
 311}
 312
 313static int poly_setkey(struct aead_request *req)
 314{
 315        struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 316        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 317        struct poly_req *preq = &rctx->u.poly;
 318        int err;
 319
 320        sg_init_one(preq->src, rctx->key, sizeof(rctx->key));
 321
 322        ahash_request_set_callback(&preq->req, rctx->flags,
 323                                   poly_setkey_done, req);
 324        ahash_request_set_tfm(&preq->req, ctx->poly);
 325        ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key));
 326
 327        err = crypto_ahash_update(&preq->req);
 328        if (err)
 329                return err;
 330
 331        return poly_ad(req);
 332}
 333
 334static void poly_init_done(struct crypto_async_request *areq, int err)
 335{
 336        async_done_continue(areq->data, err, poly_setkey);
 337}
 338
 339static int poly_init(struct aead_request *req)
 340{
 341        struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 342        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 343        struct poly_req *preq = &rctx->u.poly;
 344        int err;
 345
 346        ahash_request_set_callback(&preq->req, rctx->flags,
 347                                   poly_init_done, req);
 348        ahash_request_set_tfm(&preq->req, ctx->poly);
 349
 350        err = crypto_ahash_init(&preq->req);
 351        if (err)
 352                return err;
 353
 354        return poly_setkey(req);
 355}
 356
 357static void poly_genkey_done(struct crypto_async_request *areq, int err)
 358{
 359        async_done_continue(areq->data, err, poly_init);
 360}
 361
 362static int poly_genkey(struct aead_request *req)
 363{
 364        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 365        struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
 366        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 367        struct chacha_req *creq = &rctx->u.chacha;
 368        int err;
 369
 370        rctx->assoclen = req->assoclen;
 371
 372        if (crypto_aead_ivsize(tfm) == 8) {
 373                if (rctx->assoclen < 8)
 374                        return -EINVAL;
 375                rctx->assoclen -= 8;
 376        }
 377
 378        memset(rctx->key, 0, sizeof(rctx->key));
 379        sg_init_one(creq->src, rctx->key, sizeof(rctx->key));
 380
 381        chacha_iv(creq->iv, req, 0);
 382
 383        skcipher_request_set_callback(&creq->req, rctx->flags,
 384                                      poly_genkey_done, req);
 385        skcipher_request_set_tfm(&creq->req, ctx->chacha);
 386        skcipher_request_set_crypt(&creq->req, creq->src, creq->src,
 387                                   POLY1305_KEY_SIZE, creq->iv);
 388
 389        err = crypto_skcipher_decrypt(&creq->req);
 390        if (err)
 391                return err;
 392
 393        return poly_init(req);
 394}
 395
 396static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
 397{
 398        async_done_continue(areq->data, err, poly_genkey);
 399}
 400
 401static int chacha_encrypt(struct aead_request *req)
 402{
 403        struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 404        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 405        struct chacha_req *creq = &rctx->u.chacha;
 406        struct scatterlist *src, *dst;
 407        int err;
 408
 409        if (req->cryptlen == 0)
 410                goto skip;
 411
 412        chacha_iv(creq->iv, req, 1);
 413
 414        src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
 415        dst = src;
 416        if (req->src != req->dst)
 417                dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
 418
 419        skcipher_request_set_callback(&creq->req, rctx->flags,
 420                                      chacha_encrypt_done, req);
 421        skcipher_request_set_tfm(&creq->req, ctx->chacha);
 422        skcipher_request_set_crypt(&creq->req, src, dst,
 423                                   req->cryptlen, creq->iv);
 424        err = crypto_skcipher_encrypt(&creq->req);
 425        if (err)
 426                return err;
 427
 428skip:
 429        return poly_genkey(req);
 430}
 431
 432static int chachapoly_encrypt(struct aead_request *req)
 433{
 434        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 435
 436        rctx->cryptlen = req->cryptlen;
 437        rctx->flags = aead_request_flags(req);
 438
 439        /* encrypt call chain:
 440         * - chacha_encrypt/done()
 441         * - poly_genkey/done()
 442         * - poly_init/done()
 443         * - poly_setkey/done()
 444         * - poly_ad/done()
 445         * - poly_adpad/done()
 446         * - poly_cipher/done()
 447         * - poly_cipherpad/done()
 448         * - poly_tail/done/continue()
 449         * - poly_copy_tag()
 450         */
 451        return chacha_encrypt(req);
 452}
 453
 454static int chachapoly_decrypt(struct aead_request *req)
 455{
 456        struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 457
 458        rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE;
 459        rctx->flags = aead_request_flags(req);
 460
 461        /* decrypt call chain:
 462         * - poly_genkey/done()
 463         * - poly_init/done()
 464         * - poly_setkey/done()
 465         * - poly_ad/done()
 466         * - poly_adpad/done()
 467         * - poly_cipher/done()
 468         * - poly_cipherpad/done()
 469         * - poly_tail/done/continue()
 470         * - chacha_decrypt/done()
 471         * - poly_verify_tag()
 472         */
 473        return poly_genkey(req);
 474}
 475
 476static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key,
 477                             unsigned int keylen)
 478{
 479        struct chachapoly_ctx *ctx = crypto_aead_ctx(aead);
 480        int err;
 481
 482        if (keylen != ctx->saltlen + CHACHA_KEY_SIZE)
 483                return -EINVAL;
 484
 485        keylen -= ctx->saltlen;
 486        memcpy(ctx->salt, key + keylen, ctx->saltlen);
 487
 488        crypto_skcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK);
 489        crypto_skcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) &
 490                                               CRYPTO_TFM_REQ_MASK);
 491
 492        err = crypto_skcipher_setkey(ctx->chacha, key, keylen);
 493        crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctx->chacha) &
 494                                    CRYPTO_TFM_RES_MASK);
 495        return err;
 496}
 497
 498static int chachapoly_setauthsize(struct crypto_aead *tfm,
 499                                  unsigned int authsize)
 500{
 501        if (authsize != POLY1305_DIGEST_SIZE)
 502                return -EINVAL;
 503
 504        return 0;
 505}
 506
 507static int chachapoly_init(struct crypto_aead *tfm)
 508{
 509        struct aead_instance *inst = aead_alg_instance(tfm);
 510        struct chachapoly_instance_ctx *ictx = aead_instance_ctx(inst);
 511        struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
 512        struct crypto_skcipher *chacha;
 513        struct crypto_ahash *poly;
 514        unsigned long align;
 515
 516        poly = crypto_spawn_ahash(&ictx->poly);
 517        if (IS_ERR(poly))
 518                return PTR_ERR(poly);
 519
 520        chacha = crypto_spawn_skcipher(&ictx->chacha);
 521        if (IS_ERR(chacha)) {
 522                crypto_free_ahash(poly);
 523                return PTR_ERR(chacha);
 524        }
 525
 526        ctx->chacha = chacha;
 527        ctx->poly = poly;
 528        ctx->saltlen = ictx->saltlen;
 529
 530        align = crypto_aead_alignmask(tfm);
 531        align &= ~(crypto_tfm_ctx_alignment() - 1);
 532        crypto_aead_set_reqsize(
 533                tfm,
 534                align + offsetof(struct chachapoly_req_ctx, u) +
 535                max(offsetof(struct chacha_req, req) +
 536                    sizeof(struct skcipher_request) +
 537                    crypto_skcipher_reqsize(chacha),
 538                    offsetof(struct poly_req, req) +
 539                    sizeof(struct ahash_request) +
 540                    crypto_ahash_reqsize(poly)));
 541
 542        return 0;
 543}
 544
 545static void chachapoly_exit(struct crypto_aead *tfm)
 546{
 547        struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
 548
 549        crypto_free_ahash(ctx->poly);
 550        crypto_free_skcipher(ctx->chacha);
 551}
 552
 553static void chachapoly_free(struct aead_instance *inst)
 554{
 555        struct chachapoly_instance_ctx *ctx = aead_instance_ctx(inst);
 556
 557        crypto_drop_skcipher(&ctx->chacha);
 558        crypto_drop_ahash(&ctx->poly);
 559        kfree(inst);
 560}
 561
 562static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb,
 563                             const char *name, unsigned int ivsize)
 564{
 565        struct crypto_attr_type *algt;
 566        struct aead_instance *inst;
 567        struct skcipher_alg *chacha;
 568        struct crypto_alg *poly;
 569        struct hash_alg_common *poly_hash;
 570        struct chachapoly_instance_ctx *ctx;
 571        const char *chacha_name, *poly_name;
 572        int err;
 573
 574        if (ivsize > CHACHAPOLY_IV_SIZE)
 575                return -EINVAL;
 576
 577        algt = crypto_get_attr_type(tb);
 578        if (IS_ERR(algt))
 579                return PTR_ERR(algt);
 580
 581        if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 582                return -EINVAL;
 583
 584        chacha_name = crypto_attr_alg_name(tb[1]);
 585        if (IS_ERR(chacha_name))
 586                return PTR_ERR(chacha_name);
 587        poly_name = crypto_attr_alg_name(tb[2]);
 588        if (IS_ERR(poly_name))
 589                return PTR_ERR(poly_name);
 590
 591        poly = crypto_find_alg(poly_name, &crypto_ahash_type,
 592                               CRYPTO_ALG_TYPE_HASH,
 593                               CRYPTO_ALG_TYPE_AHASH_MASK |
 594                               crypto_requires_sync(algt->type,
 595                                                    algt->mask));
 596        if (IS_ERR(poly))
 597                return PTR_ERR(poly);
 598        poly_hash = __crypto_hash_alg_common(poly);
 599
 600        err = -EINVAL;
 601        if (poly_hash->digestsize != POLY1305_DIGEST_SIZE)
 602                goto out_put_poly;
 603
 604        err = -ENOMEM;
 605        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 606        if (!inst)
 607                goto out_put_poly;
 608
 609        ctx = aead_instance_ctx(inst);
 610        ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize;
 611        err = crypto_init_ahash_spawn(&ctx->poly, poly_hash,
 612                                      aead_crypto_instance(inst));
 613        if (err)
 614                goto err_free_inst;
 615
 616        crypto_set_skcipher_spawn(&ctx->chacha, aead_crypto_instance(inst));
 617        err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0,
 618                                   crypto_requires_sync(algt->type,
 619                                                        algt->mask));
 620        if (err)
 621                goto err_drop_poly;
 622
 623        chacha = crypto_spawn_skcipher_alg(&ctx->chacha);
 624
 625        err = -EINVAL;
 626        /* Need 16-byte IV size, including Initial Block Counter value */
 627        if (crypto_skcipher_alg_ivsize(chacha) != CHACHA_IV_SIZE)
 628                goto out_drop_chacha;
 629        /* Not a stream cipher? */
 630        if (chacha->base.cra_blocksize != 1)
 631                goto out_drop_chacha;
 632
 633        err = -ENAMETOOLONG;
 634        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 635                     "%s(%s,%s)", name, chacha->base.cra_name,
 636                     poly->cra_name) >= CRYPTO_MAX_ALG_NAME)
 637                goto out_drop_chacha;
 638        if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 639                     "%s(%s,%s)", name, chacha->base.cra_driver_name,
 640                     poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 641                goto out_drop_chacha;
 642
 643        inst->alg.base.cra_flags = (chacha->base.cra_flags | poly->cra_flags) &
 644                                   CRYPTO_ALG_ASYNC;
 645        inst->alg.base.cra_priority = (chacha->base.cra_priority +
 646                                       poly->cra_priority) / 2;
 647        inst->alg.base.cra_blocksize = 1;
 648        inst->alg.base.cra_alignmask = chacha->base.cra_alignmask |
 649                                       poly->cra_alignmask;
 650        inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) +
 651                                     ctx->saltlen;
 652        inst->alg.ivsize = ivsize;
 653        inst->alg.chunksize = crypto_skcipher_alg_chunksize(chacha);
 654        inst->alg.maxauthsize = POLY1305_DIGEST_SIZE;
 655        inst->alg.init = chachapoly_init;
 656        inst->alg.exit = chachapoly_exit;
 657        inst->alg.encrypt = chachapoly_encrypt;
 658        inst->alg.decrypt = chachapoly_decrypt;
 659        inst->alg.setkey = chachapoly_setkey;
 660        inst->alg.setauthsize = chachapoly_setauthsize;
 661
 662        inst->free = chachapoly_free;
 663
 664        err = aead_register_instance(tmpl, inst);
 665        if (err)
 666                goto out_drop_chacha;
 667
 668out_put_poly:
 669        crypto_mod_put(poly);
 670        return err;
 671
 672out_drop_chacha:
 673        crypto_drop_skcipher(&ctx->chacha);
 674err_drop_poly:
 675        crypto_drop_ahash(&ctx->poly);
 676err_free_inst:
 677        kfree(inst);
 678        goto out_put_poly;
 679}
 680
 681static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb)
 682{
 683        return chachapoly_create(tmpl, tb, "rfc7539", 12);
 684}
 685
 686static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb)
 687{
 688        return chachapoly_create(tmpl, tb, "rfc7539esp", 8);
 689}
 690
 691static struct crypto_template rfc7539_tmpls[] = {
 692        {
 693                .name = "rfc7539",
 694                .create = rfc7539_create,
 695                .module = THIS_MODULE,
 696        }, {
 697                .name = "rfc7539esp",
 698                .create = rfc7539esp_create,
 699                .module = THIS_MODULE,
 700        },
 701};
 702
 703static int __init chacha20poly1305_module_init(void)
 704{
 705        return crypto_register_templates(rfc7539_tmpls,
 706                                         ARRAY_SIZE(rfc7539_tmpls));
 707}
 708
 709static void __exit chacha20poly1305_module_exit(void)
 710{
 711        crypto_unregister_templates(rfc7539_tmpls,
 712                                    ARRAY_SIZE(rfc7539_tmpls));
 713}
 714
 715subsys_initcall(chacha20poly1305_module_init);
 716module_exit(chacha20poly1305_module_exit);
 717
 718MODULE_LICENSE("GPL");
 719MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
 720MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
 721MODULE_ALIAS_CRYPTO("rfc7539");
 722MODULE_ALIAS_CRYPTO("rfc7539esp");
 723