crypto/chacha20poly1305.c

   1 /*
   2  * ChaCha20-Poly1305 AEAD, RFC7539
   3  *
   4  * Copyright (C) 2015 Martin Willi
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <crypto/internal/aead.h>
  13 #include <crypto/internal/hash.h>
  14 #include <crypto/internal/skcipher.h>
  15 #include <crypto/scatterwalk.h>
  16 #include <linux/err.h>
  17 #include <linux/init.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20
  21 #include "internal.h"
  22
  23 #define POLY1305_BLOCK_SIZE     16
  24 #define POLY1305_DIGEST_SIZE    16
  25 #define POLY1305_KEY_SIZE       32
  26 #define CHACHA20_KEY_SIZE       32
  27 #define CHACHA20_IV_SIZE        16
  28 #define CHACHAPOLY_IV_SIZE      12
  29
  30 struct chachapoly_instance_ctx {
  31         struct crypto_skcipher_spawn chacha;
  32         struct crypto_ahash_spawn poly;
  33         unsigned int saltlen;
  34 };
  35
  36 struct chachapoly_ctx {
  37         struct crypto_ablkcipher *chacha;
  38         struct crypto_ahash *poly;
  39         /* key bytes we use for the ChaCha20 IV */
  40         unsigned int saltlen;
  41         u8 salt[];
  42 };
  43
  44 struct poly_req {
  45         /* zero byte padding for AD/ciphertext, as needed */
  46         u8 pad[POLY1305_BLOCK_SIZE];
  47         /* tail data with AD/ciphertext lengths */
  48         struct {
  49                 __le64 assoclen;
  50                 __le64 cryptlen;
  51         } tail;
  52         struct scatterlist src[1];
  53         struct ahash_request req; /* must be last member */
  54 };
  55
  56 struct chacha_req {
  57         u8 iv[CHACHA20_IV_SIZE];
  58         struct scatterlist src[1];
  59         struct ablkcipher_request req; /* must be last member */
  60 };
  61
  62 struct chachapoly_req_ctx {
  63         /* the key we generate for Poly1305 using Chacha20 */
  64         u8 key[POLY1305_KEY_SIZE];
  65         /* calculated Poly1305 tag */
  66         u8 tag[POLY1305_DIGEST_SIZE];
  67         /* length of data to en/decrypt, without ICV */
  68         unsigned int cryptlen;
  69         union {
  70                 struct poly_req poly;
  71                 struct chacha_req chacha;
  72         } u;
  73 };
  74
  75 static inline void async_done_continue(struct aead_request *req, int err,
  76                                        int (*cont)(struct aead_request *))
  77 {
  78         if (!err)
  79                 err = cont(req);
  80
  81         if (err != -EINPROGRESS && err != -EBUSY)
  82                 aead_request_complete(req, err);
  83 }
  84
  85 static void chacha_iv(u8 *iv, struct aead_request *req, u32 icb)
  86 {
  87         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
  88         __le32 leicb = cpu_to_le32(icb);
  89
  90         memcpy(iv, &leicb, sizeof(leicb));
  91         memcpy(iv + sizeof(leicb), ctx->salt, ctx->saltlen);
  92         memcpy(iv + sizeof(leicb) + ctx->saltlen, req->iv,
  93                CHACHA20_IV_SIZE - sizeof(leicb) - ctx->saltlen);
  94 }
  95
  96 static int poly_verify_tag(struct aead_request *req)
  97 {
  98         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
  99         u8 tag[sizeof(rctx->tag)];
 100
 101         scatterwalk_map_and_copy(tag, req->src, rctx->cryptlen, sizeof(tag), 0);
 102         if (crypto_memneq(tag, rctx->tag, sizeof(tag)))
 103                 return -EBADMSG;
 104         return 0;
 105 }
 106
 107 static int poly_copy_tag(struct aead_request *req)
 108 {
 109         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 110
 111         scatterwalk_map_and_copy(rctx->tag, req->dst, rctx->cryptlen,
 112                                  sizeof(rctx->tag), 1);
 113         return 0;
 114 }
 115
 116 static void chacha_decrypt_done(struct crypto_async_request *areq, int err)
 117 {
 118         async_done_continue(areq->data, err, poly_verify_tag);
 119 }
 120
 121 static int chacha_decrypt(struct aead_request *req)
 122 {
 123         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 124         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 125         struct chacha_req *creq = &rctx->u.chacha;
 126         int err;
 127
 128         chacha_iv(creq->iv, req, 1);
 129
 130         ablkcipher_request_set_callback(&creq->req, aead_request_flags(req),
 131                                         chacha_decrypt_done, req);
 132         ablkcipher_request_set_tfm(&creq->req, ctx->chacha);
 133         ablkcipher_request_set_crypt(&creq->req, req->src, req->dst,
 134                                      rctx->cryptlen, creq->iv);
 135         err = crypto_ablkcipher_decrypt(&creq->req);
 136         if (err)
 137                 return err;
 138
 139         return poly_verify_tag(req);
 140 }
 141
 142 static int poly_tail_continue(struct aead_request *req)
 143 {
 144         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 145
 146         if (rctx->cryptlen == req->cryptlen) /* encrypting */
 147                 return poly_copy_tag(req);
 148
 149         return chacha_decrypt(req);
 150 }
 151
 152 static void poly_tail_done(struct crypto_async_request *areq, int err)
 153 {
 154         async_done_continue(areq->data, err, poly_tail_continue);
 155 }
 156
 157 static int poly_tail(struct aead_request *req)
 158 {
 159         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 160         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 161         struct poly_req *preq = &rctx->u.poly;
 162         __le64 len;
 163         int err;
 164
 165         sg_init_table(preq->src, 1);
 166         len = cpu_to_le64(req->assoclen);
 167         memcpy(&preq->tail.assoclen, &len, sizeof(len));
 168         len = cpu_to_le64(rctx->cryptlen);
 169         memcpy(&preq->tail.cryptlen, &len, sizeof(len));
 170         sg_set_buf(preq->src, &preq->tail, sizeof(preq->tail));
 171
 172         ahash_request_set_callback(&preq->req, aead_request_flags(req),
 173                                    poly_tail_done, req);
 174         ahash_request_set_tfm(&preq->req, ctx->poly);
 175         ahash_request_set_crypt(&preq->req, preq->src,
 176                                 rctx->tag, sizeof(preq->tail));
 177
 178         err = crypto_ahash_finup(&preq->req);
 179         if (err)
 180                 return err;
 181
 182         return poly_tail_continue(req);
 183 }
 184
 185 static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
 186 {
 187         async_done_continue(areq->data, err, poly_tail);
 188 }
 189
 190 static int poly_cipherpad(struct aead_request *req)
 191 {
 192         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 193         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 194         struct poly_req *preq = &rctx->u.poly;
 195         unsigned int padlen, bs = POLY1305_BLOCK_SIZE;
 196         int err;
 197
 198         padlen = (bs - (rctx->cryptlen % bs)) % bs;
 199         memset(preq->pad, 0, sizeof(preq->pad));
 200         sg_init_table(preq->src, 1);
 201         sg_set_buf(preq->src, &preq->pad, padlen);
 202
 203         ahash_request_set_callback(&preq->req, aead_request_flags(req),
 204                                    poly_cipherpad_done, req);
 205         ahash_request_set_tfm(&preq->req, ctx->poly);
 206         ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
 207
 208         err = crypto_ahash_update(&preq->req);
 209         if (err)
 210                 return err;
 211
 212         return poly_tail(req);
 213 }
 214
 215 static void poly_cipher_done(struct crypto_async_request *areq, int err)
 216 {
 217         async_done_continue(areq->data, err, poly_cipherpad);
 218 }
 219
 220 static int poly_cipher(struct aead_request *req)
 221 {
 222         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 223         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 224         struct poly_req *preq = &rctx->u.poly;
 225         struct scatterlist *crypt = req->src;
 226         int err;
 227
 228         if (rctx->cryptlen == req->cryptlen) /* encrypting */
 229                 crypt = req->dst;
 230
 231         ahash_request_set_callback(&preq->req, aead_request_flags(req),
 232                                    poly_cipher_done, req);
 233         ahash_request_set_tfm(&preq->req, ctx->poly);
 234         ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen);
 235
 236         err = crypto_ahash_update(&preq->req);
 237         if (err)
 238                 return err;
 239
 240         return poly_cipherpad(req);
 241 }
 242
 243 static void poly_adpad_done(struct crypto_async_request *areq, int err)
 244 {
 245         async_done_continue(areq->data, err, poly_cipher);
 246 }
 247
 248 static int poly_adpad(struct aead_request *req)
 249 {
 250         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 251         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 252         struct poly_req *preq = &rctx->u.poly;
 253         unsigned int padlen, bs = POLY1305_BLOCK_SIZE;
 254         int err;
 255
 256         padlen = (bs - (req->assoclen % bs)) % bs;
 257         memset(preq->pad, 0, sizeof(preq->pad));
 258         sg_init_table(preq->src, 1);
 259         sg_set_buf(preq->src, preq->pad, padlen);
 260
 261         ahash_request_set_callback(&preq->req, aead_request_flags(req),
 262                                    poly_adpad_done, req);
 263         ahash_request_set_tfm(&preq->req, ctx->poly);
 264         ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
 265
 266         err = crypto_ahash_update(&preq->req);
 267         if (err)
 268                 return err;
 269
 270         return poly_cipher(req);
 271 }
 272
 273 static void poly_ad_done(struct crypto_async_request *areq, int err)
 274 {
 275         async_done_continue(areq->data, err, poly_adpad);
 276 }
 277
 278 static int poly_ad(struct aead_request *req)
 279 {
 280         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 281         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 282         struct poly_req *preq = &rctx->u.poly;
 283         int err;
 284
 285         ahash_request_set_callback(&preq->req, aead_request_flags(req),
 286                                    poly_ad_done, req);
 287         ahash_request_set_tfm(&preq->req, ctx->poly);
 288         ahash_request_set_crypt(&preq->req, req->assoc, NULL, req->assoclen);
 289
 290         err = crypto_ahash_update(&preq->req);
 291         if (err)
 292                 return err;
 293
 294         return poly_adpad(req);
 295 }
 296
 297 static void poly_setkey_done(struct crypto_async_request *areq, int err)
 298 {
 299         async_done_continue(areq->data, err, poly_ad);
 300 }
 301
 302 static int poly_setkey(struct aead_request *req)
 303 {
 304         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 305         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 306         struct poly_req *preq = &rctx->u.poly;
 307         int err;
 308
 309         sg_init_table(preq->src, 1);
 310         sg_set_buf(preq->src, rctx->key, sizeof(rctx->key));
 311
 312         ahash_request_set_callback(&preq->req, aead_request_flags(req),
 313                                    poly_setkey_done, req);
 314         ahash_request_set_tfm(&preq->req, ctx->poly);
 315         ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key));
 316
 317         err = crypto_ahash_update(&preq->req);
 318         if (err)
 319                 return err;
 320
 321         return poly_ad(req);
 322 }
 323
 324 static void poly_init_done(struct crypto_async_request *areq, int err)
 325 {
 326         async_done_continue(areq->data, err, poly_setkey);
 327 }
 328
 329 static int poly_init(struct aead_request *req)
 330 {
 331         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 332         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 333         struct poly_req *preq = &rctx->u.poly;
 334         int err;
 335
 336         ahash_request_set_callback(&preq->req, aead_request_flags(req),
 337                                    poly_init_done, req);
 338         ahash_request_set_tfm(&preq->req, ctx->poly);
 339
 340         err = crypto_ahash_init(&preq->req);
 341         if (err)
 342                 return err;
 343
 344         return poly_setkey(req);
 345 }
 346
 347 static void poly_genkey_done(struct crypto_async_request *areq, int err)
 348 {
 349         async_done_continue(areq->data, err, poly_init);
 350 }
 351
 352 static int poly_genkey(struct aead_request *req)
 353 {
 354         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 355         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 356         struct chacha_req *creq = &rctx->u.chacha;
 357         int err;
 358
 359         sg_init_table(creq->src, 1);
 360         memset(rctx->key, 0, sizeof(rctx->key));
 361         sg_set_buf(creq->src, rctx->key, sizeof(rctx->key));
 362
 363         chacha_iv(creq->iv, req, 0);
 364
 365         ablkcipher_request_set_callback(&creq->req, aead_request_flags(req),
 366                                         poly_genkey_done, req);
 367         ablkcipher_request_set_tfm(&creq->req, ctx->chacha);
 368         ablkcipher_request_set_crypt(&creq->req, creq->src, creq->src,
 369                                      POLY1305_KEY_SIZE, creq->iv);
 370
 371         err = crypto_ablkcipher_decrypt(&creq->req);
 372         if (err)
 373                 return err;
 374
 375         return poly_init(req);
 376 }
 377
 378 static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
 379 {
 380         async_done_continue(areq->data, err, poly_genkey);
 381 }
 382
 383 static int chacha_encrypt(struct aead_request *req)
 384 {
 385         struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 386         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 387         struct chacha_req *creq = &rctx->u.chacha;
 388         int err;
 389
 390         chacha_iv(creq->iv, req, 1);
 391
 392         ablkcipher_request_set_callback(&creq->req, aead_request_flags(req),
 393                                         chacha_encrypt_done, req);
 394         ablkcipher_request_set_tfm(&creq->req, ctx->chacha);
 395         ablkcipher_request_set_crypt(&creq->req, req->src, req->dst,
 396                                      req->cryptlen, creq->iv);
 397         err = crypto_ablkcipher_encrypt(&creq->req);
 398         if (err)
 399                 return err;
 400
 401         return poly_genkey(req);
 402 }
 403
 404 static int chachapoly_encrypt(struct aead_request *req)
 405 {
 406         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 407
 408         rctx->cryptlen = req->cryptlen;
 409
 410         /* encrypt call chain:
 411          * - chacha_encrypt/done()
 412          * - poly_genkey/done()
 413          * - poly_init/done()
 414          * - poly_setkey/done()
 415          * - poly_ad/done()
 416          * - poly_adpad/done()
 417          * - poly_cipher/done()
 418          * - poly_cipherpad/done()
 419          * - poly_tail/done/continue()
 420          * - poly_copy_tag()
 421          */
 422         return chacha_encrypt(req);
 423 }
 424
 425 static int chachapoly_decrypt(struct aead_request *req)
 426 {
 427         struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
 428
 429         if (req->cryptlen < POLY1305_DIGEST_SIZE)
 430                 return -EINVAL;
 431         rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE;
 432
 433         /* decrypt call chain:
 434          * - poly_genkey/done()
 435          * - poly_init/done()
 436          * - poly_setkey/done()
 437          * - poly_ad/done()
 438          * - poly_adpad/done()
 439          * - poly_cipher/done()
 440          * - poly_cipherpad/done()
 441          * - poly_tail/done/continue()
 442          * - chacha_decrypt/done()
 443          * - poly_verify_tag()
 444          */
 445         return poly_genkey(req);
 446 }
 447
 448 static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key,
 449                              unsigned int keylen)
 450 {
 451         struct chachapoly_ctx *ctx = crypto_aead_ctx(aead);
 452         int err;
 453
 454         if (keylen != ctx->saltlen + CHACHA20_KEY_SIZE)
 455                 return -EINVAL;
 456
 457         keylen -= ctx->saltlen;
 458         memcpy(ctx->salt, key + keylen, ctx->saltlen);
 459
 460         crypto_ablkcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK);
 461         crypto_ablkcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) &
 462                                     CRYPTO_TFM_REQ_MASK);
 463
 464         err = crypto_ablkcipher_setkey(ctx->chacha, key, keylen);
 465         crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctx->chacha) &
 466                               CRYPTO_TFM_RES_MASK);
 467         return err;
 468 }
 469
 470 static int chachapoly_setauthsize(struct crypto_aead *tfm,
 471                                   unsigned int authsize)
 472 {
 473         if (authsize != POLY1305_DIGEST_SIZE)
 474                 return -EINVAL;
 475
 476         return 0;
 477 }
 478
 479 static int chachapoly_init(struct crypto_tfm *tfm)
 480 {
 481         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 482         struct chachapoly_instance_ctx *ictx = crypto_instance_ctx(inst);
 483         struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm);
 484         struct crypto_ablkcipher *chacha;
 485         struct crypto_ahash *poly;
 486         unsigned long align;
 487
 488         poly = crypto_spawn_ahash(&ictx->poly);
 489         if (IS_ERR(poly))
 490                 return PTR_ERR(poly);
 491
 492         chacha = crypto_spawn_skcipher(&ictx->chacha);
 493         if (IS_ERR(chacha)) {
 494                 crypto_free_ahash(poly);
 495                 return PTR_ERR(chacha);
 496         }
 497
 498         ctx->chacha = chacha;
 499         ctx->poly = poly;
 500         ctx->saltlen = ictx->saltlen;
 501
 502         align = crypto_tfm_alg_alignmask(tfm);
 503         align &= ~(crypto_tfm_ctx_alignment() - 1);
 504         crypto_aead_set_reqsize(__crypto_aead_cast(tfm),
 505                                 align + offsetof(struct chachapoly_req_ctx, u) +
 506                                 max(offsetof(struct chacha_req, req) +
 507                                     sizeof(struct ablkcipher_request) +
 508                                     crypto_ablkcipher_reqsize(chacha),
 509                                     offsetof(struct poly_req, req) +
 510                                     sizeof(struct ahash_request) +
 511                                     crypto_ahash_reqsize(poly)));
 512
 513         return 0;
 514 }
 515
 516 static void chachapoly_exit(struct crypto_tfm *tfm)
 517 {
 518         struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm);
 519
 520         crypto_free_ahash(ctx->poly);
 521         crypto_free_ablkcipher(ctx->chacha);
 522 }
 523
 524 static struct crypto_instance *chachapoly_alloc(struct rtattr **tb,
 525                                                 const char *name,
 526                                                 unsigned int ivsize)
 527 {
 528         struct crypto_attr_type *algt;
 529         struct crypto_instance *inst;
 530         struct crypto_alg *chacha;
 531         struct crypto_alg *poly;
 532         struct ahash_alg *poly_ahash;
 533         struct chachapoly_instance_ctx *ctx;
 534         const char *chacha_name, *poly_name;
 535         int err;
 536
 537         if (ivsize > CHACHAPOLY_IV_SIZE)
 538                 return ERR_PTR(-EINVAL);
 539
 540         algt = crypto_get_attr_type(tb);
 541         if (IS_ERR(algt))
 542                 return ERR_CAST(algt);
 543
 544         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 545                 return ERR_PTR(-EINVAL);
 546
 547         chacha_name = crypto_attr_alg_name(tb[1]);
 548         if (IS_ERR(chacha_name))
 549                 return ERR_CAST(chacha_name);
 550         poly_name = crypto_attr_alg_name(tb[2]);
 551         if (IS_ERR(poly_name))
 552                 return ERR_CAST(poly_name);
 553
 554         poly = crypto_find_alg(poly_name, &crypto_ahash_type,
 555                                CRYPTO_ALG_TYPE_HASH,
 556                                CRYPTO_ALG_TYPE_AHASH_MASK);
 557         if (IS_ERR(poly))
 558                 return ERR_CAST(poly);
 559
 560         err = -ENOMEM;
 561         inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 562         if (!inst)
 563                 goto out_put_poly;
 564
 565         ctx = crypto_instance_ctx(inst);
 566         ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize;
 567         poly_ahash = container_of(poly, struct ahash_alg, halg.base);
 568         err = crypto_init_ahash_spawn(&ctx->poly, &poly_ahash->halg, inst);
 569         if (err)
 570                 goto err_free_inst;
 571
 572         crypto_set_skcipher_spawn(&ctx->chacha, inst);
 573         err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0,
 574                                    crypto_requires_sync(algt->type,
 575                                                         algt->mask));
 576         if (err)
 577                 goto err_drop_poly;
 578
 579         chacha = crypto_skcipher_spawn_alg(&ctx->chacha);
 580
 581         err = -EINVAL;
 582         /* Need 16-byte IV size, including Initial Block Counter value */
 583         if (chacha->cra_ablkcipher.ivsize != CHACHA20_IV_SIZE)
 584                 goto out_drop_chacha;
 585         /* Not a stream cipher? */
 586         if (chacha->cra_blocksize != 1)
 587                 goto out_drop_chacha;
 588
 589         err = -ENAMETOOLONG;
 590         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 591                      "%s(%s,%s)", name, chacha_name,
 592                      poly_name) >= CRYPTO_MAX_ALG_NAME)
 593                 goto out_drop_chacha;
 594         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 595                      "%s(%s,%s)", name, chacha->cra_driver_name,
 596                      poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 597                 goto out_drop_chacha;
 598
 599         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
 600         inst->alg.cra_flags |= (chacha->cra_flags |
 601                                 poly->cra_flags) & CRYPTO_ALG_ASYNC;
 602         inst->alg.cra_priority = (chacha->cra_priority +
 603                                   poly->cra_priority) / 2;
 604         inst->alg.cra_blocksize = 1;
 605         inst->alg.cra_alignmask = chacha->cra_alignmask | poly->cra_alignmask;
 606         inst->alg.cra_type = &crypto_nivaead_type;
 607         inst->alg.cra_aead.ivsize = ivsize;
 608         inst->alg.cra_aead.maxauthsize = POLY1305_DIGEST_SIZE;
 609         inst->alg.cra_ctxsize = sizeof(struct chachapoly_ctx) + ctx->saltlen;
 610         inst->alg.cra_init = chachapoly_init;
 611         inst->alg.cra_exit = chachapoly_exit;
 612         inst->alg.cra_aead.encrypt = chachapoly_encrypt;
 613         inst->alg.cra_aead.decrypt = chachapoly_decrypt;
 614         inst->alg.cra_aead.setkey = chachapoly_setkey;
 615         inst->alg.cra_aead.setauthsize = chachapoly_setauthsize;
 616         inst->alg.cra_aead.geniv = "seqiv";
 617
 618 out:
 619         crypto_mod_put(poly);
 620         return inst;
 621
 622 out_drop_chacha:
 623         crypto_drop_skcipher(&ctx->chacha);
 624 err_drop_poly:
 625         crypto_drop_ahash(&ctx->poly);
 626 err_free_inst:
 627         kfree(inst);
 628 out_put_poly:
 629         inst = ERR_PTR(err);
 630         goto out;
 631 }
 632
 633 static struct crypto_instance *rfc7539_alloc(struct rtattr **tb)
 634 {
 635         return chachapoly_alloc(tb, "rfc7539", 12);
 636 }
 637
 638 static struct crypto_instance *rfc7539esp_alloc(struct rtattr **tb)
 639 {
 640         return chachapoly_alloc(tb, "rfc7539esp", 8);
 641 }
 642
 643 static void chachapoly_free(struct crypto_instance *inst)
 644 {
 645         struct chachapoly_instance_ctx *ctx = crypto_instance_ctx(inst);
 646
 647         crypto_drop_skcipher(&ctx->chacha);
 648         crypto_drop_ahash(&ctx->poly);
 649         kfree(inst);
 650 }
 651
 652 static struct crypto_template rfc7539_tmpl = {
 653         .name = "rfc7539",
 654         .alloc = rfc7539_alloc,
 655         .free = chachapoly_free,
 656         .module = THIS_MODULE,
 657 };
 658
 659 static struct crypto_template rfc7539esp_tmpl = {
 660         .name = "rfc7539esp",
 661         .alloc = rfc7539esp_alloc,
 662         .free = chachapoly_free,
 663         .module = THIS_MODULE,
 664 };
 665
 666 static int __init chacha20poly1305_module_init(void)
 667 {
 668         int err;
 669
 670         err = crypto_register_template(&rfc7539_tmpl);
 671         if (err)
 672                 return err;
 673
 674         err = crypto_register_template(&rfc7539esp_tmpl);
 675         if (err)
 676                 crypto_unregister_template(&rfc7539_tmpl);
 677
 678         return err;
 679 }
 680
 681 static void __exit chacha20poly1305_module_exit(void)
 682 {
 683         crypto_unregister_template(&rfc7539esp_tmpl);
 684         crypto_unregister_template(&rfc7539_tmpl);
 685 }
 686
 687 module_init(chacha20poly1305_module_init);
 688 module_exit(chacha20poly1305_module_exit);
 689
 690 MODULE_LICENSE("GPL");
 691 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
 692 MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
 693 MODULE_ALIAS_CRYPTO("chacha20poly1305");
 694 MODULE_ALIAS_CRYPTO("rfc7539");
 695 MODULE_ALIAS_CRYPTO("rfc7539esp");