Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [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> |
Martin Willi | 31d7247 | 2015-07-16 19:14:00 +0200 | [diff] [blame] | 16 | #include <crypto/chacha20.h> |
Martin Willi | 2546f81 | 2015-07-16 19:14:05 +0200 | [diff] [blame] | 17 | #include <crypto/poly1305.h> |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 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 | |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 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_ablkcipher *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 { |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 54 | u8 iv[CHACHA20_IV_SIZE]; |
| 55 | struct scatterlist src[1]; |
| 56 | struct ablkcipher_request req; /* must be last member */ |
| 57 | }; |
| 58 | |
| 59 | struct chachapoly_req_ctx { |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 60 | struct scatterlist src[2]; |
| 61 | struct scatterlist dst[2]; |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 62 | /* the key we generate for Poly1305 using Chacha20 */ |
| 63 | u8 key[POLY1305_KEY_SIZE]; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 64 | /* calculated Poly1305 tag */ |
| 65 | u8 tag[POLY1305_DIGEST_SIZE]; |
| 66 | /* length of data to en/decrypt, without ICV */ |
| 67 | unsigned int cryptlen; |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 68 | /* Actual AD, excluding IV */ |
| 69 | unsigned int assoclen; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 70 | union { |
| 71 | struct poly_req poly; |
| 72 | struct chacha_req chacha; |
| 73 | } u; |
| 74 | }; |
| 75 | |
| 76 | static inline void async_done_continue(struct aead_request *req, int err, |
| 77 | int (*cont)(struct aead_request *)) |
| 78 | { |
| 79 | if (!err) |
| 80 | err = cont(req); |
| 81 | |
| 82 | if (err != -EINPROGRESS && err != -EBUSY) |
| 83 | aead_request_complete(req, err); |
| 84 | } |
| 85 | |
| 86 | static 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 | CHACHA20_IV_SIZE - sizeof(leicb) - ctx->saltlen); |
| 95 | } |
| 96 | |
| 97 | static 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 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 102 | scatterwalk_map_and_copy(tag, req->src, |
| 103 | req->assoclen + rctx->cryptlen, |
| 104 | sizeof(tag), 0); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 105 | if (crypto_memneq(tag, rctx->tag, sizeof(tag))) |
| 106 | return -EBADMSG; |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | static int poly_copy_tag(struct aead_request *req) |
| 111 | { |
| 112 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 113 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 114 | scatterwalk_map_and_copy(rctx->tag, req->dst, |
| 115 | req->assoclen + rctx->cryptlen, |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 116 | sizeof(rctx->tag), 1); |
| 117 | return 0; |
| 118 | } |
| 119 | |
| 120 | static void chacha_decrypt_done(struct crypto_async_request *areq, int err) |
| 121 | { |
| 122 | async_done_continue(areq->data, err, poly_verify_tag); |
| 123 | } |
| 124 | |
| 125 | static 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; |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 130 | struct scatterlist *src, *dst; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 131 | int err; |
| 132 | |
| 133 | chacha_iv(creq->iv, req, 1); |
| 134 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 135 | sg_init_table(rctx->src, 2); |
| 136 | src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); |
| 137 | dst = src; |
| 138 | |
| 139 | if (req->src != req->dst) { |
| 140 | sg_init_table(rctx->dst, 2); |
| 141 | dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); |
| 142 | } |
| 143 | |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 144 | ablkcipher_request_set_callback(&creq->req, aead_request_flags(req), |
| 145 | chacha_decrypt_done, req); |
| 146 | ablkcipher_request_set_tfm(&creq->req, ctx->chacha); |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 147 | ablkcipher_request_set_crypt(&creq->req, src, dst, |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 148 | rctx->cryptlen, creq->iv); |
| 149 | err = crypto_ablkcipher_decrypt(&creq->req); |
| 150 | if (err) |
| 151 | return err; |
| 152 | |
| 153 | return poly_verify_tag(req); |
| 154 | } |
| 155 | |
| 156 | static 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 | |
| 166 | static void poly_tail_done(struct crypto_async_request *areq, int err) |
| 167 | { |
| 168 | async_done_continue(areq->data, err, poly_tail_continue); |
| 169 | } |
| 170 | |
| 171 | static int poly_tail(struct aead_request *req) |
| 172 | { |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 173 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); |
| 174 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 175 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 176 | struct poly_req *preq = &rctx->u.poly; |
| 177 | __le64 len; |
| 178 | int err; |
| 179 | |
| 180 | sg_init_table(preq->src, 1); |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 181 | len = cpu_to_le64(rctx->assoclen); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 182 | memcpy(&preq->tail.assoclen, &len, sizeof(len)); |
| 183 | len = cpu_to_le64(rctx->cryptlen); |
| 184 | memcpy(&preq->tail.cryptlen, &len, sizeof(len)); |
| 185 | sg_set_buf(preq->src, &preq->tail, sizeof(preq->tail)); |
| 186 | |
| 187 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
| 188 | poly_tail_done, req); |
| 189 | ahash_request_set_tfm(&preq->req, ctx->poly); |
| 190 | ahash_request_set_crypt(&preq->req, preq->src, |
| 191 | rctx->tag, sizeof(preq->tail)); |
| 192 | |
| 193 | err = crypto_ahash_finup(&preq->req); |
| 194 | if (err) |
| 195 | return err; |
| 196 | |
| 197 | return poly_tail_continue(req); |
| 198 | } |
| 199 | |
| 200 | static void poly_cipherpad_done(struct crypto_async_request *areq, int err) |
| 201 | { |
| 202 | async_done_continue(areq->data, err, poly_tail); |
| 203 | } |
| 204 | |
| 205 | static int poly_cipherpad(struct aead_request *req) |
| 206 | { |
| 207 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
| 208 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 209 | struct poly_req *preq = &rctx->u.poly; |
| 210 | unsigned int padlen, bs = POLY1305_BLOCK_SIZE; |
| 211 | int err; |
| 212 | |
| 213 | padlen = (bs - (rctx->cryptlen % bs)) % bs; |
| 214 | memset(preq->pad, 0, sizeof(preq->pad)); |
| 215 | sg_init_table(preq->src, 1); |
| 216 | sg_set_buf(preq->src, &preq->pad, padlen); |
| 217 | |
| 218 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
| 219 | poly_cipherpad_done, req); |
| 220 | ahash_request_set_tfm(&preq->req, ctx->poly); |
| 221 | ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); |
| 222 | |
| 223 | err = crypto_ahash_update(&preq->req); |
| 224 | if (err) |
| 225 | return err; |
| 226 | |
| 227 | return poly_tail(req); |
| 228 | } |
| 229 | |
| 230 | static void poly_cipher_done(struct crypto_async_request *areq, int err) |
| 231 | { |
| 232 | async_done_continue(areq->data, err, poly_cipherpad); |
| 233 | } |
| 234 | |
| 235 | static int poly_cipher(struct aead_request *req) |
| 236 | { |
| 237 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
| 238 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 239 | struct poly_req *preq = &rctx->u.poly; |
| 240 | struct scatterlist *crypt = req->src; |
| 241 | int err; |
| 242 | |
| 243 | if (rctx->cryptlen == req->cryptlen) /* encrypting */ |
| 244 | crypt = req->dst; |
| 245 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 246 | sg_init_table(rctx->src, 2); |
| 247 | crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen); |
| 248 | |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 249 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
| 250 | poly_cipher_done, req); |
| 251 | ahash_request_set_tfm(&preq->req, ctx->poly); |
| 252 | ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen); |
| 253 | |
| 254 | err = crypto_ahash_update(&preq->req); |
| 255 | if (err) |
| 256 | return err; |
| 257 | |
| 258 | return poly_cipherpad(req); |
| 259 | } |
| 260 | |
| 261 | static void poly_adpad_done(struct crypto_async_request *areq, int err) |
| 262 | { |
| 263 | async_done_continue(areq->data, err, poly_cipher); |
| 264 | } |
| 265 | |
| 266 | static int poly_adpad(struct aead_request *req) |
| 267 | { |
| 268 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
| 269 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 270 | struct poly_req *preq = &rctx->u.poly; |
| 271 | unsigned int padlen, bs = POLY1305_BLOCK_SIZE; |
| 272 | int err; |
| 273 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 274 | padlen = (bs - (rctx->assoclen % bs)) % bs; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 275 | memset(preq->pad, 0, sizeof(preq->pad)); |
| 276 | sg_init_table(preq->src, 1); |
| 277 | sg_set_buf(preq->src, preq->pad, padlen); |
| 278 | |
| 279 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
| 280 | poly_adpad_done, req); |
| 281 | ahash_request_set_tfm(&preq->req, ctx->poly); |
| 282 | ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); |
| 283 | |
| 284 | err = crypto_ahash_update(&preq->req); |
| 285 | if (err) |
| 286 | return err; |
| 287 | |
| 288 | return poly_cipher(req); |
| 289 | } |
| 290 | |
| 291 | static void poly_ad_done(struct crypto_async_request *areq, int err) |
| 292 | { |
| 293 | async_done_continue(areq->data, err, poly_adpad); |
| 294 | } |
| 295 | |
| 296 | static int poly_ad(struct aead_request *req) |
| 297 | { |
| 298 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
| 299 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 300 | struct poly_req *preq = &rctx->u.poly; |
| 301 | int err; |
| 302 | |
| 303 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
| 304 | poly_ad_done, req); |
| 305 | ahash_request_set_tfm(&preq->req, ctx->poly); |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 306 | ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 307 | |
| 308 | err = crypto_ahash_update(&preq->req); |
| 309 | if (err) |
| 310 | return err; |
| 311 | |
| 312 | return poly_adpad(req); |
| 313 | } |
| 314 | |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 315 | static void poly_setkey_done(struct crypto_async_request *areq, int err) |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 316 | { |
| 317 | async_done_continue(areq->data, err, poly_ad); |
| 318 | } |
| 319 | |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 320 | static int poly_setkey(struct aead_request *req) |
| 321 | { |
| 322 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
| 323 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 324 | struct poly_req *preq = &rctx->u.poly; |
| 325 | int err; |
| 326 | |
| 327 | sg_init_table(preq->src, 1); |
| 328 | sg_set_buf(preq->src, rctx->key, sizeof(rctx->key)); |
| 329 | |
| 330 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
| 331 | poly_setkey_done, req); |
| 332 | ahash_request_set_tfm(&preq->req, ctx->poly); |
| 333 | ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key)); |
| 334 | |
| 335 | err = crypto_ahash_update(&preq->req); |
| 336 | if (err) |
| 337 | return err; |
| 338 | |
| 339 | return poly_ad(req); |
| 340 | } |
| 341 | |
| 342 | static void poly_init_done(struct crypto_async_request *areq, int err) |
| 343 | { |
| 344 | async_done_continue(areq->data, err, poly_setkey); |
| 345 | } |
| 346 | |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 347 | static int poly_init(struct aead_request *req) |
| 348 | { |
| 349 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
| 350 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 351 | struct poly_req *preq = &rctx->u.poly; |
| 352 | int err; |
| 353 | |
| 354 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
| 355 | poly_init_done, req); |
| 356 | ahash_request_set_tfm(&preq->req, ctx->poly); |
| 357 | |
| 358 | err = crypto_ahash_init(&preq->req); |
| 359 | if (err) |
| 360 | return err; |
| 361 | |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 362 | return poly_setkey(req); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 363 | } |
| 364 | |
| 365 | static void poly_genkey_done(struct crypto_async_request *areq, int err) |
| 366 | { |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 367 | async_done_continue(areq->data, err, poly_init); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 368 | } |
| 369 | |
| 370 | static int poly_genkey(struct aead_request *req) |
| 371 | { |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 372 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); |
| 373 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 374 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 375 | struct chacha_req *creq = &rctx->u.chacha; |
| 376 | int err; |
| 377 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 378 | rctx->assoclen = req->assoclen; |
| 379 | |
| 380 | if (crypto_aead_ivsize(tfm) == 8) { |
| 381 | if (rctx->assoclen < 8) |
| 382 | return -EINVAL; |
| 383 | rctx->assoclen -= 8; |
| 384 | } |
| 385 | |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 386 | sg_init_table(creq->src, 1); |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 387 | memset(rctx->key, 0, sizeof(rctx->key)); |
| 388 | sg_set_buf(creq->src, rctx->key, sizeof(rctx->key)); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 389 | |
| 390 | chacha_iv(creq->iv, req, 0); |
| 391 | |
| 392 | ablkcipher_request_set_callback(&creq->req, aead_request_flags(req), |
| 393 | poly_genkey_done, req); |
| 394 | ablkcipher_request_set_tfm(&creq->req, ctx->chacha); |
| 395 | ablkcipher_request_set_crypt(&creq->req, creq->src, creq->src, |
| 396 | POLY1305_KEY_SIZE, creq->iv); |
| 397 | |
| 398 | err = crypto_ablkcipher_decrypt(&creq->req); |
| 399 | if (err) |
| 400 | return err; |
| 401 | |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 402 | return poly_init(req); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 403 | } |
| 404 | |
| 405 | static void chacha_encrypt_done(struct crypto_async_request *areq, int err) |
| 406 | { |
| 407 | async_done_continue(areq->data, err, poly_genkey); |
| 408 | } |
| 409 | |
| 410 | static int chacha_encrypt(struct aead_request *req) |
| 411 | { |
| 412 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
| 413 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 414 | struct chacha_req *creq = &rctx->u.chacha; |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 415 | struct scatterlist *src, *dst; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 416 | int err; |
| 417 | |
| 418 | chacha_iv(creq->iv, req, 1); |
| 419 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 420 | sg_init_table(rctx->src, 2); |
| 421 | src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); |
| 422 | dst = src; |
| 423 | |
| 424 | if (req->src != req->dst) { |
| 425 | sg_init_table(rctx->dst, 2); |
| 426 | dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); |
| 427 | } |
| 428 | |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 429 | ablkcipher_request_set_callback(&creq->req, aead_request_flags(req), |
| 430 | chacha_encrypt_done, req); |
| 431 | ablkcipher_request_set_tfm(&creq->req, ctx->chacha); |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 432 | ablkcipher_request_set_crypt(&creq->req, src, dst, |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 433 | req->cryptlen, creq->iv); |
| 434 | err = crypto_ablkcipher_encrypt(&creq->req); |
| 435 | if (err) |
| 436 | return err; |
| 437 | |
| 438 | return poly_genkey(req); |
| 439 | } |
| 440 | |
| 441 | static int chachapoly_encrypt(struct aead_request *req) |
| 442 | { |
| 443 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 444 | |
| 445 | rctx->cryptlen = req->cryptlen; |
| 446 | |
| 447 | /* encrypt call chain: |
| 448 | * - chacha_encrypt/done() |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 449 | * - poly_genkey/done() |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 450 | * - poly_init/done() |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 451 | * - poly_setkey/done() |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 452 | * - poly_ad/done() |
| 453 | * - poly_adpad/done() |
| 454 | * - poly_cipher/done() |
| 455 | * - poly_cipherpad/done() |
| 456 | * - poly_tail/done/continue() |
| 457 | * - poly_copy_tag() |
| 458 | */ |
| 459 | return chacha_encrypt(req); |
| 460 | } |
| 461 | |
| 462 | static int chachapoly_decrypt(struct aead_request *req) |
| 463 | { |
| 464 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
| 465 | |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 466 | rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE; |
| 467 | |
| 468 | /* decrypt call chain: |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 469 | * - poly_genkey/done() |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 470 | * - poly_init/done() |
Martin Willi | c2b7b20a | 2015-06-16 11:34:16 +0200 | [diff] [blame] | 471 | * - poly_setkey/done() |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 472 | * - poly_ad/done() |
| 473 | * - poly_adpad/done() |
| 474 | * - poly_cipher/done() |
| 475 | * - poly_cipherpad/done() |
| 476 | * - poly_tail/done/continue() |
| 477 | * - chacha_decrypt/done() |
| 478 | * - poly_verify_tag() |
| 479 | */ |
| 480 | return poly_genkey(req); |
| 481 | } |
| 482 | |
| 483 | static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key, |
| 484 | unsigned int keylen) |
| 485 | { |
| 486 | struct chachapoly_ctx *ctx = crypto_aead_ctx(aead); |
| 487 | int err; |
| 488 | |
| 489 | if (keylen != ctx->saltlen + CHACHA20_KEY_SIZE) |
| 490 | return -EINVAL; |
| 491 | |
| 492 | keylen -= ctx->saltlen; |
| 493 | memcpy(ctx->salt, key + keylen, ctx->saltlen); |
| 494 | |
| 495 | crypto_ablkcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK); |
| 496 | crypto_ablkcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) & |
| 497 | CRYPTO_TFM_REQ_MASK); |
| 498 | |
| 499 | err = crypto_ablkcipher_setkey(ctx->chacha, key, keylen); |
| 500 | crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctx->chacha) & |
| 501 | CRYPTO_TFM_RES_MASK); |
| 502 | return err; |
| 503 | } |
| 504 | |
| 505 | static int chachapoly_setauthsize(struct crypto_aead *tfm, |
| 506 | unsigned int authsize) |
| 507 | { |
| 508 | if (authsize != POLY1305_DIGEST_SIZE) |
| 509 | return -EINVAL; |
| 510 | |
| 511 | return 0; |
| 512 | } |
| 513 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 514 | static int chachapoly_init(struct crypto_aead *tfm) |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 515 | { |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 516 | struct aead_instance *inst = aead_alg_instance(tfm); |
| 517 | struct chachapoly_instance_ctx *ictx = aead_instance_ctx(inst); |
| 518 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 519 | struct crypto_ablkcipher *chacha; |
| 520 | struct crypto_ahash *poly; |
| 521 | unsigned long align; |
| 522 | |
| 523 | poly = crypto_spawn_ahash(&ictx->poly); |
| 524 | if (IS_ERR(poly)) |
| 525 | return PTR_ERR(poly); |
| 526 | |
| 527 | chacha = crypto_spawn_skcipher(&ictx->chacha); |
| 528 | if (IS_ERR(chacha)) { |
| 529 | crypto_free_ahash(poly); |
| 530 | return PTR_ERR(chacha); |
| 531 | } |
| 532 | |
| 533 | ctx->chacha = chacha; |
| 534 | ctx->poly = poly; |
| 535 | ctx->saltlen = ictx->saltlen; |
| 536 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 537 | align = crypto_aead_alignmask(tfm); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 538 | align &= ~(crypto_tfm_ctx_alignment() - 1); |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 539 | crypto_aead_set_reqsize( |
| 540 | tfm, |
| 541 | align + offsetof(struct chachapoly_req_ctx, u) + |
| 542 | max(offsetof(struct chacha_req, req) + |
| 543 | sizeof(struct ablkcipher_request) + |
| 544 | crypto_ablkcipher_reqsize(chacha), |
| 545 | offsetof(struct poly_req, req) + |
| 546 | sizeof(struct ahash_request) + |
| 547 | crypto_ahash_reqsize(poly))); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 548 | |
| 549 | return 0; |
| 550 | } |
| 551 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 552 | static void chachapoly_exit(struct crypto_aead *tfm) |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 553 | { |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 554 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 555 | |
| 556 | crypto_free_ahash(ctx->poly); |
| 557 | crypto_free_ablkcipher(ctx->chacha); |
| 558 | } |
| 559 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 560 | static void chachapoly_free(struct aead_instance *inst) |
| 561 | { |
| 562 | struct chachapoly_instance_ctx *ctx = aead_instance_ctx(inst); |
| 563 | |
| 564 | crypto_drop_skcipher(&ctx->chacha); |
| 565 | crypto_drop_ahash(&ctx->poly); |
| 566 | kfree(inst); |
| 567 | } |
| 568 | |
| 569 | static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb, |
| 570 | const char *name, unsigned int ivsize) |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 571 | { |
| 572 | struct crypto_attr_type *algt; |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 573 | struct aead_instance *inst; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 574 | struct crypto_alg *chacha; |
| 575 | struct crypto_alg *poly; |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 576 | struct hash_alg_common *poly_hash; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 577 | struct chachapoly_instance_ctx *ctx; |
| 578 | const char *chacha_name, *poly_name; |
| 579 | int err; |
| 580 | |
| 581 | if (ivsize > CHACHAPOLY_IV_SIZE) |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 582 | return -EINVAL; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 583 | |
| 584 | algt = crypto_get_attr_type(tb); |
| 585 | if (IS_ERR(algt)) |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 586 | return PTR_ERR(algt); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 587 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 588 | if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_AEAD_NEW)) & |
| 589 | algt->mask) |
| 590 | return -EINVAL; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 591 | |
| 592 | chacha_name = crypto_attr_alg_name(tb[1]); |
| 593 | if (IS_ERR(chacha_name)) |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 594 | return PTR_ERR(chacha_name); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 595 | poly_name = crypto_attr_alg_name(tb[2]); |
| 596 | if (IS_ERR(poly_name)) |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 597 | return PTR_ERR(poly_name); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 598 | |
| 599 | poly = crypto_find_alg(poly_name, &crypto_ahash_type, |
| 600 | CRYPTO_ALG_TYPE_HASH, |
| 601 | CRYPTO_ALG_TYPE_AHASH_MASK); |
| 602 | if (IS_ERR(poly)) |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 603 | return PTR_ERR(poly); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 604 | |
| 605 | err = -ENOMEM; |
| 606 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); |
| 607 | if (!inst) |
| 608 | goto out_put_poly; |
| 609 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 610 | ctx = aead_instance_ctx(inst); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 611 | ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize; |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 612 | poly_hash = __crypto_hash_alg_common(poly); |
| 613 | err = crypto_init_ahash_spawn(&ctx->poly, poly_hash, |
| 614 | aead_crypto_instance(inst)); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 615 | if (err) |
| 616 | goto err_free_inst; |
| 617 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 618 | crypto_set_skcipher_spawn(&ctx->chacha, aead_crypto_instance(inst)); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 619 | err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0, |
| 620 | crypto_requires_sync(algt->type, |
| 621 | algt->mask)); |
| 622 | if (err) |
| 623 | goto err_drop_poly; |
| 624 | |
| 625 | chacha = crypto_skcipher_spawn_alg(&ctx->chacha); |
| 626 | |
| 627 | err = -EINVAL; |
| 628 | /* Need 16-byte IV size, including Initial Block Counter value */ |
| 629 | if (chacha->cra_ablkcipher.ivsize != CHACHA20_IV_SIZE) |
| 630 | goto out_drop_chacha; |
| 631 | /* Not a stream cipher? */ |
| 632 | if (chacha->cra_blocksize != 1) |
| 633 | goto out_drop_chacha; |
| 634 | |
| 635 | err = -ENAMETOOLONG; |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 636 | if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 637 | "%s(%s,%s)", name, chacha_name, |
| 638 | poly_name) >= CRYPTO_MAX_ALG_NAME) |
| 639 | goto out_drop_chacha; |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 640 | if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 641 | "%s(%s,%s)", name, chacha->cra_driver_name, |
| 642 | poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) |
| 643 | goto out_drop_chacha; |
| 644 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 645 | inst->alg.base.cra_flags = (chacha->cra_flags | poly->cra_flags) & |
| 646 | CRYPTO_ALG_ASYNC; |
| 647 | inst->alg.base.cra_flags |= CRYPTO_ALG_AEAD_NEW; |
| 648 | inst->alg.base.cra_priority = (chacha->cra_priority + |
| 649 | poly->cra_priority) / 2; |
| 650 | inst->alg.base.cra_blocksize = 1; |
| 651 | inst->alg.base.cra_alignmask = chacha->cra_alignmask | |
| 652 | poly->cra_alignmask; |
| 653 | inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) + |
| 654 | ctx->saltlen; |
| 655 | inst->alg.ivsize = ivsize; |
| 656 | inst->alg.maxauthsize = POLY1305_DIGEST_SIZE; |
| 657 | inst->alg.init = chachapoly_init; |
| 658 | inst->alg.exit = chachapoly_exit; |
| 659 | inst->alg.encrypt = chachapoly_encrypt; |
| 660 | inst->alg.decrypt = chachapoly_decrypt; |
| 661 | inst->alg.setkey = chachapoly_setkey; |
| 662 | inst->alg.setauthsize = chachapoly_setauthsize; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 663 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 664 | inst->free = chachapoly_free; |
| 665 | |
| 666 | err = aead_register_instance(tmpl, inst); |
| 667 | if (err) |
| 668 | goto out_drop_chacha; |
| 669 | |
| 670 | out_put_poly: |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 671 | crypto_mod_put(poly); |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 672 | return err; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 673 | |
| 674 | out_drop_chacha: |
| 675 | crypto_drop_skcipher(&ctx->chacha); |
| 676 | err_drop_poly: |
| 677 | crypto_drop_ahash(&ctx->poly); |
| 678 | err_free_inst: |
| 679 | kfree(inst); |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 680 | goto out_put_poly; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 681 | } |
| 682 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 683 | static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb) |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 684 | { |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 685 | return chachapoly_create(tmpl, tb, "rfc7539", 12); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 686 | } |
| 687 | |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 688 | static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb) |
Martin Willi | 4db4ad2 | 2015-06-01 13:44:02 +0200 | [diff] [blame] | 689 | { |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 690 | return chachapoly_create(tmpl, tb, "rfc7539esp", 8); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 691 | } |
| 692 | |
| 693 | static struct crypto_template rfc7539_tmpl = { |
| 694 | .name = "rfc7539", |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 695 | .create = rfc7539_create, |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 696 | .module = THIS_MODULE, |
| 697 | }; |
| 698 | |
Martin Willi | 4db4ad2 | 2015-06-01 13:44:02 +0200 | [diff] [blame] | 699 | static struct crypto_template rfc7539esp_tmpl = { |
| 700 | .name = "rfc7539esp", |
Herbert Xu | 7479092 | 2015-07-16 12:35:08 +0800 | [diff] [blame] | 701 | .create = rfc7539esp_create, |
Martin Willi | 4db4ad2 | 2015-06-01 13:44:02 +0200 | [diff] [blame] | 702 | .module = THIS_MODULE, |
| 703 | }; |
| 704 | |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 705 | static int __init chacha20poly1305_module_init(void) |
| 706 | { |
Martin Willi | 4db4ad2 | 2015-06-01 13:44:02 +0200 | [diff] [blame] | 707 | int err; |
| 708 | |
| 709 | err = crypto_register_template(&rfc7539_tmpl); |
| 710 | if (err) |
| 711 | return err; |
| 712 | |
| 713 | err = crypto_register_template(&rfc7539esp_tmpl); |
| 714 | if (err) |
| 715 | crypto_unregister_template(&rfc7539_tmpl); |
| 716 | |
| 717 | return err; |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 718 | } |
| 719 | |
| 720 | static void __exit chacha20poly1305_module_exit(void) |
| 721 | { |
Martin Willi | 4db4ad2 | 2015-06-01 13:44:02 +0200 | [diff] [blame] | 722 | crypto_unregister_template(&rfc7539esp_tmpl); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 723 | crypto_unregister_template(&rfc7539_tmpl); |
| 724 | } |
| 725 | |
| 726 | module_init(chacha20poly1305_module_init); |
| 727 | module_exit(chacha20poly1305_module_exit); |
| 728 | |
| 729 | MODULE_LICENSE("GPL"); |
| 730 | MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); |
| 731 | MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD"); |
Martin Willi | 71ebc4d | 2015-06-01 13:44:00 +0200 | [diff] [blame] | 732 | MODULE_ALIAS_CRYPTO("rfc7539"); |
Martin Willi | 4db4ad2 | 2015-06-01 13:44:02 +0200 | [diff] [blame] | 733 | MODULE_ALIAS_CRYPTO("rfc7539esp"); |