| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame] | 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 <crypto/chacha20.h> | 
|  | 17 | #include <crypto/poly1305.h> | 
|  | 18 | #include <linux/err.h> | 
|  | 19 | #include <linux/init.h> | 
|  | 20 | #include <linux/kernel.h> | 
|  | 21 | #include <linux/module.h> | 
|  | 22 |  | 
|  | 23 | #include "internal.h" | 
|  | 24 |  | 
|  | 25 | #define CHACHAPOLY_IV_SIZE	12 | 
|  | 26 |  | 
|  | 27 | struct chachapoly_instance_ctx { | 
|  | 28 | struct crypto_skcipher_spawn chacha; | 
|  | 29 | struct crypto_ahash_spawn poly; | 
|  | 30 | unsigned int saltlen; | 
|  | 31 | }; | 
|  | 32 |  | 
|  | 33 | struct chachapoly_ctx { | 
|  | 34 | struct crypto_skcipher *chacha; | 
|  | 35 | struct crypto_ahash *poly; | 
|  | 36 | /* key bytes we use for the ChaCha20 IV */ | 
|  | 37 | unsigned int saltlen; | 
|  | 38 | u8 salt[]; | 
|  | 39 | }; | 
|  | 40 |  | 
|  | 41 | struct poly_req { | 
|  | 42 | /* zero byte padding for AD/ciphertext, as needed */ | 
|  | 43 | u8 pad[POLY1305_BLOCK_SIZE]; | 
|  | 44 | /* tail data with AD/ciphertext lengths */ | 
|  | 45 | struct { | 
|  | 46 | __le64 assoclen; | 
|  | 47 | __le64 cryptlen; | 
|  | 48 | } tail; | 
|  | 49 | struct scatterlist src[1]; | 
|  | 50 | struct ahash_request req; /* must be last member */ | 
|  | 51 | }; | 
|  | 52 |  | 
|  | 53 | struct chacha_req { | 
|  | 54 | u8 iv[CHACHA20_IV_SIZE]; | 
|  | 55 | struct scatterlist src[1]; | 
|  | 56 | struct skcipher_request req; /* must be last member */ | 
|  | 57 | }; | 
|  | 58 |  | 
|  | 59 | struct chachapoly_req_ctx { | 
|  | 60 | struct scatterlist src[2]; | 
|  | 61 | struct scatterlist dst[2]; | 
|  | 62 | /* the key we generate for Poly1305 using Chacha20 */ | 
|  | 63 | u8 key[POLY1305_KEY_SIZE]; | 
|  | 64 | /* calculated Poly1305 tag */ | 
|  | 65 | u8 tag[POLY1305_DIGEST_SIZE]; | 
|  | 66 | /* length of data to en/decrypt, without ICV */ | 
|  | 67 | unsigned int cryptlen; | 
|  | 68 | /* Actual AD, excluding IV */ | 
|  | 69 | unsigned int assoclen; | 
|  | 70 | /* request flags, with MAY_SLEEP cleared if needed */ | 
|  | 71 | u32 flags; | 
|  | 72 | union { | 
|  | 73 | struct poly_req poly; | 
|  | 74 | struct chacha_req chacha; | 
|  | 75 | } u; | 
|  | 76 | }; | 
|  | 77 |  | 
|  | 78 | static inline void async_done_continue(struct aead_request *req, int err, | 
|  | 79 | int (*cont)(struct aead_request *)) | 
|  | 80 | { | 
|  | 81 | if (!err) { | 
|  | 82 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 83 |  | 
|  | 84 | rctx->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; | 
|  | 85 | err = cont(req); | 
|  | 86 | } | 
|  | 87 |  | 
|  | 88 | if (err != -EINPROGRESS && err != -EBUSY) | 
|  | 89 | aead_request_complete(req, err); | 
|  | 90 | } | 
|  | 91 |  | 
|  | 92 | static void chacha_iv(u8 *iv, struct aead_request *req, u32 icb) | 
|  | 93 | { | 
|  | 94 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | 
|  | 95 | __le32 leicb = cpu_to_le32(icb); | 
|  | 96 |  | 
|  | 97 | memcpy(iv, &leicb, sizeof(leicb)); | 
|  | 98 | memcpy(iv + sizeof(leicb), ctx->salt, ctx->saltlen); | 
|  | 99 | memcpy(iv + sizeof(leicb) + ctx->saltlen, req->iv, | 
|  | 100 | CHACHA20_IV_SIZE - sizeof(leicb) - ctx->saltlen); | 
|  | 101 | } | 
|  | 102 |  | 
|  | 103 | static int poly_verify_tag(struct aead_request *req) | 
|  | 104 | { | 
|  | 105 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 106 | u8 tag[sizeof(rctx->tag)]; | 
|  | 107 |  | 
|  | 108 | scatterwalk_map_and_copy(tag, req->src, | 
|  | 109 | req->assoclen + rctx->cryptlen, | 
|  | 110 | sizeof(tag), 0); | 
|  | 111 | if (crypto_memneq(tag, rctx->tag, sizeof(tag))) | 
|  | 112 | return -EBADMSG; | 
|  | 113 | return 0; | 
|  | 114 | } | 
|  | 115 |  | 
|  | 116 | static int poly_copy_tag(struct aead_request *req) | 
|  | 117 | { | 
|  | 118 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 119 |  | 
|  | 120 | scatterwalk_map_and_copy(rctx->tag, req->dst, | 
|  | 121 | req->assoclen + rctx->cryptlen, | 
|  | 122 | sizeof(rctx->tag), 1); | 
|  | 123 | return 0; | 
|  | 124 | } | 
|  | 125 |  | 
|  | 126 | static void chacha_decrypt_done(struct crypto_async_request *areq, int err) | 
|  | 127 | { | 
|  | 128 | async_done_continue(areq->data, err, poly_verify_tag); | 
|  | 129 | } | 
|  | 130 |  | 
|  | 131 | static int chacha_decrypt(struct aead_request *req) | 
|  | 132 | { | 
|  | 133 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | 
|  | 134 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 135 | struct chacha_req *creq = &rctx->u.chacha; | 
|  | 136 | struct scatterlist *src, *dst; | 
|  | 137 | int err; | 
|  | 138 |  | 
|  | 139 | if (rctx->cryptlen == 0) | 
|  | 140 | goto skip; | 
|  | 141 |  | 
|  | 142 | chacha_iv(creq->iv, req, 1); | 
|  | 143 |  | 
|  | 144 | sg_init_table(rctx->src, 2); | 
|  | 145 | src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); | 
|  | 146 | dst = src; | 
|  | 147 |  | 
|  | 148 | if (req->src != req->dst) { | 
|  | 149 | sg_init_table(rctx->dst, 2); | 
|  | 150 | dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); | 
|  | 151 | } | 
|  | 152 |  | 
|  | 153 | skcipher_request_set_callback(&creq->req, rctx->flags, | 
|  | 154 | chacha_decrypt_done, req); | 
|  | 155 | skcipher_request_set_tfm(&creq->req, ctx->chacha); | 
|  | 156 | skcipher_request_set_crypt(&creq->req, src, dst, | 
|  | 157 | rctx->cryptlen, creq->iv); | 
|  | 158 | err = crypto_skcipher_decrypt(&creq->req); | 
|  | 159 | if (err) | 
|  | 160 | return err; | 
|  | 161 |  | 
|  | 162 | skip: | 
|  | 163 | return poly_verify_tag(req); | 
|  | 164 | } | 
|  | 165 |  | 
|  | 166 | static int poly_tail_continue(struct aead_request *req) | 
|  | 167 | { | 
|  | 168 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 169 |  | 
|  | 170 | if (rctx->cryptlen == req->cryptlen) /* encrypting */ | 
|  | 171 | return poly_copy_tag(req); | 
|  | 172 |  | 
|  | 173 | return chacha_decrypt(req); | 
|  | 174 | } | 
|  | 175 |  | 
|  | 176 | static void poly_tail_done(struct crypto_async_request *areq, int err) | 
|  | 177 | { | 
|  | 178 | async_done_continue(areq->data, err, poly_tail_continue); | 
|  | 179 | } | 
|  | 180 |  | 
|  | 181 | static int poly_tail(struct aead_request *req) | 
|  | 182 | { | 
|  | 183 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); | 
|  | 184 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); | 
|  | 185 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 186 | struct poly_req *preq = &rctx->u.poly; | 
|  | 187 | __le64 len; | 
|  | 188 | int err; | 
|  | 189 |  | 
|  | 190 | sg_init_table(preq->src, 1); | 
|  | 191 | len = cpu_to_le64(rctx->assoclen); | 
|  | 192 | memcpy(&preq->tail.assoclen, &len, sizeof(len)); | 
|  | 193 | len = cpu_to_le64(rctx->cryptlen); | 
|  | 194 | memcpy(&preq->tail.cryptlen, &len, sizeof(len)); | 
|  | 195 | sg_set_buf(preq->src, &preq->tail, sizeof(preq->tail)); | 
|  | 196 |  | 
|  | 197 | ahash_request_set_callback(&preq->req, rctx->flags, | 
|  | 198 | poly_tail_done, req); | 
|  | 199 | ahash_request_set_tfm(&preq->req, ctx->poly); | 
|  | 200 | ahash_request_set_crypt(&preq->req, preq->src, | 
|  | 201 | rctx->tag, sizeof(preq->tail)); | 
|  | 202 |  | 
|  | 203 | err = crypto_ahash_finup(&preq->req); | 
|  | 204 | if (err) | 
|  | 205 | return err; | 
|  | 206 |  | 
|  | 207 | return poly_tail_continue(req); | 
|  | 208 | } | 
|  | 209 |  | 
|  | 210 | static void poly_cipherpad_done(struct crypto_async_request *areq, int err) | 
|  | 211 | { | 
|  | 212 | async_done_continue(areq->data, err, poly_tail); | 
|  | 213 | } | 
|  | 214 |  | 
|  | 215 | static int poly_cipherpad(struct aead_request *req) | 
|  | 216 | { | 
|  | 217 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | 
|  | 218 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 219 | struct poly_req *preq = &rctx->u.poly; | 
|  | 220 | unsigned int padlen, bs = POLY1305_BLOCK_SIZE; | 
|  | 221 | int err; | 
|  | 222 |  | 
|  | 223 | padlen = (bs - (rctx->cryptlen % bs)) % bs; | 
|  | 224 | memset(preq->pad, 0, sizeof(preq->pad)); | 
|  | 225 | sg_init_table(preq->src, 1); | 
|  | 226 | sg_set_buf(preq->src, &preq->pad, padlen); | 
|  | 227 |  | 
|  | 228 | ahash_request_set_callback(&preq->req, rctx->flags, | 
|  | 229 | poly_cipherpad_done, req); | 
|  | 230 | ahash_request_set_tfm(&preq->req, ctx->poly); | 
|  | 231 | ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); | 
|  | 232 |  | 
|  | 233 | err = crypto_ahash_update(&preq->req); | 
|  | 234 | if (err) | 
|  | 235 | return err; | 
|  | 236 |  | 
|  | 237 | return poly_tail(req); | 
|  | 238 | } | 
|  | 239 |  | 
|  | 240 | static void poly_cipher_done(struct crypto_async_request *areq, int err) | 
|  | 241 | { | 
|  | 242 | async_done_continue(areq->data, err, poly_cipherpad); | 
|  | 243 | } | 
|  | 244 |  | 
|  | 245 | static int poly_cipher(struct aead_request *req) | 
|  | 246 | { | 
|  | 247 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | 
|  | 248 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 249 | struct poly_req *preq = &rctx->u.poly; | 
|  | 250 | struct scatterlist *crypt = req->src; | 
|  | 251 | int err; | 
|  | 252 |  | 
|  | 253 | if (rctx->cryptlen == req->cryptlen) /* encrypting */ | 
|  | 254 | crypt = req->dst; | 
|  | 255 |  | 
|  | 256 | sg_init_table(rctx->src, 2); | 
|  | 257 | crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen); | 
|  | 258 |  | 
|  | 259 | ahash_request_set_callback(&preq->req, rctx->flags, | 
|  | 260 | poly_cipher_done, req); | 
|  | 261 | ahash_request_set_tfm(&preq->req, ctx->poly); | 
|  | 262 | ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen); | 
|  | 263 |  | 
|  | 264 | err = crypto_ahash_update(&preq->req); | 
|  | 265 | if (err) | 
|  | 266 | return err; | 
|  | 267 |  | 
|  | 268 | return poly_cipherpad(req); | 
|  | 269 | } | 
|  | 270 |  | 
|  | 271 | static void poly_adpad_done(struct crypto_async_request *areq, int err) | 
|  | 272 | { | 
|  | 273 | async_done_continue(areq->data, err, poly_cipher); | 
|  | 274 | } | 
|  | 275 |  | 
|  | 276 | static int poly_adpad(struct aead_request *req) | 
|  | 277 | { | 
|  | 278 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | 
|  | 279 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 280 | struct poly_req *preq = &rctx->u.poly; | 
|  | 281 | unsigned int padlen, bs = POLY1305_BLOCK_SIZE; | 
|  | 282 | int err; | 
|  | 283 |  | 
|  | 284 | padlen = (bs - (rctx->assoclen % bs)) % bs; | 
|  | 285 | memset(preq->pad, 0, sizeof(preq->pad)); | 
|  | 286 | sg_init_table(preq->src, 1); | 
|  | 287 | sg_set_buf(preq->src, preq->pad, padlen); | 
|  | 288 |  | 
|  | 289 | ahash_request_set_callback(&preq->req, rctx->flags, | 
|  | 290 | poly_adpad_done, req); | 
|  | 291 | ahash_request_set_tfm(&preq->req, ctx->poly); | 
|  | 292 | ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); | 
|  | 293 |  | 
|  | 294 | err = crypto_ahash_update(&preq->req); | 
|  | 295 | if (err) | 
|  | 296 | return err; | 
|  | 297 |  | 
|  | 298 | return poly_cipher(req); | 
|  | 299 | } | 
|  | 300 |  | 
|  | 301 | static void poly_ad_done(struct crypto_async_request *areq, int err) | 
|  | 302 | { | 
|  | 303 | async_done_continue(areq->data, err, poly_adpad); | 
|  | 304 | } | 
|  | 305 |  | 
|  | 306 | static int poly_ad(struct aead_request *req) | 
|  | 307 | { | 
|  | 308 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | 
|  | 309 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 310 | struct poly_req *preq = &rctx->u.poly; | 
|  | 311 | int err; | 
|  | 312 |  | 
|  | 313 | ahash_request_set_callback(&preq->req, rctx->flags, | 
|  | 314 | poly_ad_done, req); | 
|  | 315 | ahash_request_set_tfm(&preq->req, ctx->poly); | 
|  | 316 | ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen); | 
|  | 317 |  | 
|  | 318 | err = crypto_ahash_update(&preq->req); | 
|  | 319 | if (err) | 
|  | 320 | return err; | 
|  | 321 |  | 
|  | 322 | return poly_adpad(req); | 
|  | 323 | } | 
|  | 324 |  | 
|  | 325 | static void poly_setkey_done(struct crypto_async_request *areq, int err) | 
|  | 326 | { | 
|  | 327 | async_done_continue(areq->data, err, poly_ad); | 
|  | 328 | } | 
|  | 329 |  | 
|  | 330 | static int poly_setkey(struct aead_request *req) | 
|  | 331 | { | 
|  | 332 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | 
|  | 333 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 334 | struct poly_req *preq = &rctx->u.poly; | 
|  | 335 | int err; | 
|  | 336 |  | 
|  | 337 | sg_init_table(preq->src, 1); | 
|  | 338 | sg_set_buf(preq->src, rctx->key, sizeof(rctx->key)); | 
|  | 339 |  | 
|  | 340 | ahash_request_set_callback(&preq->req, rctx->flags, | 
|  | 341 | poly_setkey_done, req); | 
|  | 342 | ahash_request_set_tfm(&preq->req, ctx->poly); | 
|  | 343 | ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key)); | 
|  | 344 |  | 
|  | 345 | err = crypto_ahash_update(&preq->req); | 
|  | 346 | if (err) | 
|  | 347 | return err; | 
|  | 348 |  | 
|  | 349 | return poly_ad(req); | 
|  | 350 | } | 
|  | 351 |  | 
|  | 352 | static void poly_init_done(struct crypto_async_request *areq, int err) | 
|  | 353 | { | 
|  | 354 | async_done_continue(areq->data, err, poly_setkey); | 
|  | 355 | } | 
|  | 356 |  | 
|  | 357 | static int poly_init(struct aead_request *req) | 
|  | 358 | { | 
|  | 359 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | 
|  | 360 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 361 | struct poly_req *preq = &rctx->u.poly; | 
|  | 362 | int err; | 
|  | 363 |  | 
|  | 364 | ahash_request_set_callback(&preq->req, rctx->flags, | 
|  | 365 | poly_init_done, req); | 
|  | 366 | ahash_request_set_tfm(&preq->req, ctx->poly); | 
|  | 367 |  | 
|  | 368 | err = crypto_ahash_init(&preq->req); | 
|  | 369 | if (err) | 
|  | 370 | return err; | 
|  | 371 |  | 
|  | 372 | return poly_setkey(req); | 
|  | 373 | } | 
|  | 374 |  | 
|  | 375 | static void poly_genkey_done(struct crypto_async_request *areq, int err) | 
|  | 376 | { | 
|  | 377 | async_done_continue(areq->data, err, poly_init); | 
|  | 378 | } | 
|  | 379 |  | 
|  | 380 | static int poly_genkey(struct aead_request *req) | 
|  | 381 | { | 
|  | 382 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); | 
|  | 383 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); | 
|  | 384 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 385 | struct chacha_req *creq = &rctx->u.chacha; | 
|  | 386 | int err; | 
|  | 387 |  | 
|  | 388 | rctx->assoclen = req->assoclen; | 
|  | 389 |  | 
|  | 390 | if (crypto_aead_ivsize(tfm) == 8) { | 
|  | 391 | if (rctx->assoclen < 8) | 
|  | 392 | return -EINVAL; | 
|  | 393 | rctx->assoclen -= 8; | 
|  | 394 | } | 
|  | 395 |  | 
|  | 396 | sg_init_table(creq->src, 1); | 
|  | 397 | memset(rctx->key, 0, sizeof(rctx->key)); | 
|  | 398 | sg_set_buf(creq->src, rctx->key, sizeof(rctx->key)); | 
|  | 399 |  | 
|  | 400 | chacha_iv(creq->iv, req, 0); | 
|  | 401 |  | 
|  | 402 | skcipher_request_set_callback(&creq->req, rctx->flags, | 
|  | 403 | poly_genkey_done, req); | 
|  | 404 | skcipher_request_set_tfm(&creq->req, ctx->chacha); | 
|  | 405 | skcipher_request_set_crypt(&creq->req, creq->src, creq->src, | 
|  | 406 | POLY1305_KEY_SIZE, creq->iv); | 
|  | 407 |  | 
|  | 408 | err = crypto_skcipher_decrypt(&creq->req); | 
|  | 409 | if (err) | 
|  | 410 | return err; | 
|  | 411 |  | 
|  | 412 | return poly_init(req); | 
|  | 413 | } | 
|  | 414 |  | 
|  | 415 | static void chacha_encrypt_done(struct crypto_async_request *areq, int err) | 
|  | 416 | { | 
|  | 417 | async_done_continue(areq->data, err, poly_genkey); | 
|  | 418 | } | 
|  | 419 |  | 
|  | 420 | static int chacha_encrypt(struct aead_request *req) | 
|  | 421 | { | 
|  | 422 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | 
|  | 423 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 424 | struct chacha_req *creq = &rctx->u.chacha; | 
|  | 425 | struct scatterlist *src, *dst; | 
|  | 426 | int err; | 
|  | 427 |  | 
|  | 428 | if (req->cryptlen == 0) | 
|  | 429 | goto skip; | 
|  | 430 |  | 
|  | 431 | chacha_iv(creq->iv, req, 1); | 
|  | 432 |  | 
|  | 433 | sg_init_table(rctx->src, 2); | 
|  | 434 | src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); | 
|  | 435 | dst = src; | 
|  | 436 |  | 
|  | 437 | if (req->src != req->dst) { | 
|  | 438 | sg_init_table(rctx->dst, 2); | 
|  | 439 | dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); | 
|  | 440 | } | 
|  | 441 |  | 
|  | 442 | skcipher_request_set_callback(&creq->req, rctx->flags, | 
|  | 443 | chacha_encrypt_done, req); | 
|  | 444 | skcipher_request_set_tfm(&creq->req, ctx->chacha); | 
|  | 445 | skcipher_request_set_crypt(&creq->req, src, dst, | 
|  | 446 | req->cryptlen, creq->iv); | 
|  | 447 | err = crypto_skcipher_encrypt(&creq->req); | 
|  | 448 | if (err) | 
|  | 449 | return err; | 
|  | 450 |  | 
|  | 451 | skip: | 
|  | 452 | return poly_genkey(req); | 
|  | 453 | } | 
|  | 454 |  | 
|  | 455 | static int chachapoly_encrypt(struct aead_request *req) | 
|  | 456 | { | 
|  | 457 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 458 |  | 
|  | 459 | rctx->cryptlen = req->cryptlen; | 
|  | 460 | rctx->flags = aead_request_flags(req); | 
|  | 461 |  | 
|  | 462 | /* encrypt call chain: | 
|  | 463 | * - chacha_encrypt/done() | 
|  | 464 | * - poly_genkey/done() | 
|  | 465 | * - poly_init/done() | 
|  | 466 | * - poly_setkey/done() | 
|  | 467 | * - poly_ad/done() | 
|  | 468 | * - poly_adpad/done() | 
|  | 469 | * - poly_cipher/done() | 
|  | 470 | * - poly_cipherpad/done() | 
|  | 471 | * - poly_tail/done/continue() | 
|  | 472 | * - poly_copy_tag() | 
|  | 473 | */ | 
|  | 474 | return chacha_encrypt(req); | 
|  | 475 | } | 
|  | 476 |  | 
|  | 477 | static int chachapoly_decrypt(struct aead_request *req) | 
|  | 478 | { | 
|  | 479 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | 
|  | 480 |  | 
|  | 481 | rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE; | 
|  | 482 | rctx->flags = aead_request_flags(req); | 
|  | 483 |  | 
|  | 484 | /* decrypt call chain: | 
|  | 485 | * - poly_genkey/done() | 
|  | 486 | * - poly_init/done() | 
|  | 487 | * - poly_setkey/done() | 
|  | 488 | * - poly_ad/done() | 
|  | 489 | * - poly_adpad/done() | 
|  | 490 | * - poly_cipher/done() | 
|  | 491 | * - poly_cipherpad/done() | 
|  | 492 | * - poly_tail/done/continue() | 
|  | 493 | * - chacha_decrypt/done() | 
|  | 494 | * - poly_verify_tag() | 
|  | 495 | */ | 
|  | 496 | return poly_genkey(req); | 
|  | 497 | } | 
|  | 498 |  | 
|  | 499 | static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key, | 
|  | 500 | unsigned int keylen) | 
|  | 501 | { | 
|  | 502 | struct chachapoly_ctx *ctx = crypto_aead_ctx(aead); | 
|  | 503 | int err; | 
|  | 504 |  | 
|  | 505 | if (keylen != ctx->saltlen + CHACHA20_KEY_SIZE) | 
|  | 506 | return -EINVAL; | 
|  | 507 |  | 
|  | 508 | keylen -= ctx->saltlen; | 
|  | 509 | memcpy(ctx->salt, key + keylen, ctx->saltlen); | 
|  | 510 |  | 
|  | 511 | crypto_skcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK); | 
|  | 512 | crypto_skcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) & | 
|  | 513 | CRYPTO_TFM_REQ_MASK); | 
|  | 514 |  | 
|  | 515 | err = crypto_skcipher_setkey(ctx->chacha, key, keylen); | 
|  | 516 | crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctx->chacha) & | 
|  | 517 | CRYPTO_TFM_RES_MASK); | 
|  | 518 | return err; | 
|  | 519 | } | 
|  | 520 |  | 
|  | 521 | static int chachapoly_setauthsize(struct crypto_aead *tfm, | 
|  | 522 | unsigned int authsize) | 
|  | 523 | { | 
|  | 524 | if (authsize != POLY1305_DIGEST_SIZE) | 
|  | 525 | return -EINVAL; | 
|  | 526 |  | 
|  | 527 | return 0; | 
|  | 528 | } | 
|  | 529 |  | 
|  | 530 | static int chachapoly_init(struct crypto_aead *tfm) | 
|  | 531 | { | 
|  | 532 | struct aead_instance *inst = aead_alg_instance(tfm); | 
|  | 533 | struct chachapoly_instance_ctx *ictx = aead_instance_ctx(inst); | 
|  | 534 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); | 
|  | 535 | struct crypto_skcipher *chacha; | 
|  | 536 | struct crypto_ahash *poly; | 
|  | 537 | unsigned long align; | 
|  | 538 |  | 
|  | 539 | poly = crypto_spawn_ahash(&ictx->poly); | 
|  | 540 | if (IS_ERR(poly)) | 
|  | 541 | return PTR_ERR(poly); | 
|  | 542 |  | 
|  | 543 | chacha = crypto_spawn_skcipher(&ictx->chacha); | 
|  | 544 | if (IS_ERR(chacha)) { | 
|  | 545 | crypto_free_ahash(poly); | 
|  | 546 | return PTR_ERR(chacha); | 
|  | 547 | } | 
|  | 548 |  | 
|  | 549 | ctx->chacha = chacha; | 
|  | 550 | ctx->poly = poly; | 
|  | 551 | ctx->saltlen = ictx->saltlen; | 
|  | 552 |  | 
|  | 553 | align = crypto_aead_alignmask(tfm); | 
|  | 554 | align &= ~(crypto_tfm_ctx_alignment() - 1); | 
|  | 555 | crypto_aead_set_reqsize( | 
|  | 556 | tfm, | 
|  | 557 | align + offsetof(struct chachapoly_req_ctx, u) + | 
|  | 558 | max(offsetof(struct chacha_req, req) + | 
|  | 559 | sizeof(struct skcipher_request) + | 
|  | 560 | crypto_skcipher_reqsize(chacha), | 
|  | 561 | offsetof(struct poly_req, req) + | 
|  | 562 | sizeof(struct ahash_request) + | 
|  | 563 | crypto_ahash_reqsize(poly))); | 
|  | 564 |  | 
|  | 565 | return 0; | 
|  | 566 | } | 
|  | 567 |  | 
|  | 568 | static void chachapoly_exit(struct crypto_aead *tfm) | 
|  | 569 | { | 
|  | 570 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); | 
|  | 571 |  | 
|  | 572 | crypto_free_ahash(ctx->poly); | 
|  | 573 | crypto_free_skcipher(ctx->chacha); | 
|  | 574 | } | 
|  | 575 |  | 
|  | 576 | static void chachapoly_free(struct aead_instance *inst) | 
|  | 577 | { | 
|  | 578 | struct chachapoly_instance_ctx *ctx = aead_instance_ctx(inst); | 
|  | 579 |  | 
|  | 580 | crypto_drop_skcipher(&ctx->chacha); | 
|  | 581 | crypto_drop_ahash(&ctx->poly); | 
|  | 582 | kfree(inst); | 
|  | 583 | } | 
|  | 584 |  | 
|  | 585 | static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb, | 
|  | 586 | const char *name, unsigned int ivsize) | 
|  | 587 | { | 
|  | 588 | struct crypto_attr_type *algt; | 
|  | 589 | struct aead_instance *inst; | 
|  | 590 | struct skcipher_alg *chacha; | 
|  | 591 | struct crypto_alg *poly; | 
|  | 592 | struct hash_alg_common *poly_hash; | 
|  | 593 | struct chachapoly_instance_ctx *ctx; | 
|  | 594 | const char *chacha_name, *poly_name; | 
|  | 595 | int err; | 
|  | 596 |  | 
|  | 597 | if (ivsize > CHACHAPOLY_IV_SIZE) | 
|  | 598 | return -EINVAL; | 
|  | 599 |  | 
|  | 600 | algt = crypto_get_attr_type(tb); | 
|  | 601 | if (IS_ERR(algt)) | 
|  | 602 | return PTR_ERR(algt); | 
|  | 603 |  | 
|  | 604 | if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) | 
|  | 605 | return -EINVAL; | 
|  | 606 |  | 
|  | 607 | chacha_name = crypto_attr_alg_name(tb[1]); | 
|  | 608 | if (IS_ERR(chacha_name)) | 
|  | 609 | return PTR_ERR(chacha_name); | 
|  | 610 | poly_name = crypto_attr_alg_name(tb[2]); | 
|  | 611 | if (IS_ERR(poly_name)) | 
|  | 612 | return PTR_ERR(poly_name); | 
|  | 613 |  | 
|  | 614 | poly = crypto_find_alg(poly_name, &crypto_ahash_type, | 
|  | 615 | CRYPTO_ALG_TYPE_HASH, | 
|  | 616 | CRYPTO_ALG_TYPE_AHASH_MASK | | 
|  | 617 | crypto_requires_sync(algt->type, | 
|  | 618 | algt->mask)); | 
|  | 619 | if (IS_ERR(poly)) | 
|  | 620 | return PTR_ERR(poly); | 
|  | 621 | poly_hash = __crypto_hash_alg_common(poly); | 
|  | 622 |  | 
|  | 623 | err = -EINVAL; | 
|  | 624 | if (poly_hash->digestsize != POLY1305_DIGEST_SIZE) | 
|  | 625 | goto out_put_poly; | 
|  | 626 |  | 
|  | 627 | err = -ENOMEM; | 
|  | 628 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | 
|  | 629 | if (!inst) | 
|  | 630 | goto out_put_poly; | 
|  | 631 |  | 
|  | 632 | ctx = aead_instance_ctx(inst); | 
|  | 633 | ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize; | 
|  | 634 | err = crypto_init_ahash_spawn(&ctx->poly, poly_hash, | 
|  | 635 | aead_crypto_instance(inst)); | 
|  | 636 | if (err) | 
|  | 637 | goto err_free_inst; | 
|  | 638 |  | 
|  | 639 | crypto_set_skcipher_spawn(&ctx->chacha, aead_crypto_instance(inst)); | 
|  | 640 | err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0, | 
|  | 641 | crypto_requires_sync(algt->type, | 
|  | 642 | algt->mask)); | 
|  | 643 | if (err) | 
|  | 644 | goto err_drop_poly; | 
|  | 645 |  | 
|  | 646 | chacha = crypto_spawn_skcipher_alg(&ctx->chacha); | 
|  | 647 |  | 
|  | 648 | err = -EINVAL; | 
|  | 649 | /* Need 16-byte IV size, including Initial Block Counter value */ | 
|  | 650 | if (crypto_skcipher_alg_ivsize(chacha) != CHACHA20_IV_SIZE) | 
|  | 651 | goto out_drop_chacha; | 
|  | 652 | /* Not a stream cipher? */ | 
|  | 653 | if (chacha->base.cra_blocksize != 1) | 
|  | 654 | goto out_drop_chacha; | 
|  | 655 |  | 
|  | 656 | err = -ENAMETOOLONG; | 
|  | 657 | if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, | 
|  | 658 | "%s(%s,%s)", name, chacha->base.cra_name, | 
|  | 659 | poly->cra_name) >= CRYPTO_MAX_ALG_NAME) | 
|  | 660 | goto out_drop_chacha; | 
|  | 661 | if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, | 
|  | 662 | "%s(%s,%s)", name, chacha->base.cra_driver_name, | 
|  | 663 | poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) | 
|  | 664 | goto out_drop_chacha; | 
|  | 665 |  | 
|  | 666 | inst->alg.base.cra_flags = (chacha->base.cra_flags | poly->cra_flags) & | 
|  | 667 | CRYPTO_ALG_ASYNC; | 
|  | 668 | inst->alg.base.cra_priority = (chacha->base.cra_priority + | 
|  | 669 | poly->cra_priority) / 2; | 
|  | 670 | inst->alg.base.cra_blocksize = 1; | 
|  | 671 | inst->alg.base.cra_alignmask = chacha->base.cra_alignmask | | 
|  | 672 | poly->cra_alignmask; | 
|  | 673 | inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) + | 
|  | 674 | ctx->saltlen; | 
|  | 675 | inst->alg.ivsize = ivsize; | 
|  | 676 | inst->alg.chunksize = crypto_skcipher_alg_chunksize(chacha); | 
|  | 677 | inst->alg.maxauthsize = POLY1305_DIGEST_SIZE; | 
|  | 678 | inst->alg.init = chachapoly_init; | 
|  | 679 | inst->alg.exit = chachapoly_exit; | 
|  | 680 | inst->alg.encrypt = chachapoly_encrypt; | 
|  | 681 | inst->alg.decrypt = chachapoly_decrypt; | 
|  | 682 | inst->alg.setkey = chachapoly_setkey; | 
|  | 683 | inst->alg.setauthsize = chachapoly_setauthsize; | 
|  | 684 |  | 
|  | 685 | inst->free = chachapoly_free; | 
|  | 686 |  | 
|  | 687 | err = aead_register_instance(tmpl, inst); | 
|  | 688 | if (err) | 
|  | 689 | goto out_drop_chacha; | 
|  | 690 |  | 
|  | 691 | out_put_poly: | 
|  | 692 | crypto_mod_put(poly); | 
|  | 693 | return err; | 
|  | 694 |  | 
|  | 695 | out_drop_chacha: | 
|  | 696 | crypto_drop_skcipher(&ctx->chacha); | 
|  | 697 | err_drop_poly: | 
|  | 698 | crypto_drop_ahash(&ctx->poly); | 
|  | 699 | err_free_inst: | 
|  | 700 | kfree(inst); | 
|  | 701 | goto out_put_poly; | 
|  | 702 | } | 
|  | 703 |  | 
|  | 704 | static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb) | 
|  | 705 | { | 
|  | 706 | return chachapoly_create(tmpl, tb, "rfc7539", 12); | 
|  | 707 | } | 
|  | 708 |  | 
|  | 709 | static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb) | 
|  | 710 | { | 
|  | 711 | return chachapoly_create(tmpl, tb, "rfc7539esp", 8); | 
|  | 712 | } | 
|  | 713 |  | 
|  | 714 | static struct crypto_template rfc7539_tmpl = { | 
|  | 715 | .name = "rfc7539", | 
|  | 716 | .create = rfc7539_create, | 
|  | 717 | .module = THIS_MODULE, | 
|  | 718 | }; | 
|  | 719 |  | 
|  | 720 | static struct crypto_template rfc7539esp_tmpl = { | 
|  | 721 | .name = "rfc7539esp", | 
|  | 722 | .create = rfc7539esp_create, | 
|  | 723 | .module = THIS_MODULE, | 
|  | 724 | }; | 
|  | 725 |  | 
|  | 726 | static int __init chacha20poly1305_module_init(void) | 
|  | 727 | { | 
|  | 728 | int err; | 
|  | 729 |  | 
|  | 730 | err = crypto_register_template(&rfc7539_tmpl); | 
|  | 731 | if (err) | 
|  | 732 | return err; | 
|  | 733 |  | 
|  | 734 | err = crypto_register_template(&rfc7539esp_tmpl); | 
|  | 735 | if (err) | 
|  | 736 | crypto_unregister_template(&rfc7539_tmpl); | 
|  | 737 |  | 
|  | 738 | return err; | 
|  | 739 | } | 
|  | 740 |  | 
|  | 741 | static void __exit chacha20poly1305_module_exit(void) | 
|  | 742 | { | 
|  | 743 | crypto_unregister_template(&rfc7539esp_tmpl); | 
|  | 744 | crypto_unregister_template(&rfc7539_tmpl); | 
|  | 745 | } | 
|  | 746 |  | 
|  | 747 | module_init(chacha20poly1305_module_init); | 
|  | 748 | module_exit(chacha20poly1305_module_exit); | 
|  | 749 |  | 
|  | 750 | MODULE_LICENSE("GPL"); | 
|  | 751 | MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); | 
|  | 752 | MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD"); | 
|  | 753 | MODULE_ALIAS_CRYPTO("rfc7539"); | 
|  | 754 | MODULE_ALIAS_CRYPTO("rfc7539esp"); |