Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Authenc: Simple AEAD wrapper for IPsec |
| 3 | * |
| 4 | * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify it |
| 7 | * under the terms of the GNU General Public License as published by the Free |
| 8 | * Software Foundation; either version 2 of the License, or (at your option) |
| 9 | * any later version. |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <crypto/algapi.h> |
Herbert Xu | e236d4a | 2007-11-22 23:11:53 +0800 | [diff] [blame] | 14 | #include <crypto/authenc.h> |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 15 | #include <linux/err.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/module.h> |
Herbert Xu | e236d4a | 2007-11-22 23:11:53 +0800 | [diff] [blame] | 19 | #include <linux/rtnetlink.h> |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 20 | #include <linux/slab.h> |
| 21 | #include <linux/spinlock.h> |
| 22 | |
| 23 | #include "scatterwalk.h" |
| 24 | |
| 25 | struct authenc_instance_ctx { |
| 26 | struct crypto_spawn auth; |
| 27 | struct crypto_spawn enc; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 28 | }; |
| 29 | |
| 30 | struct crypto_authenc_ctx { |
| 31 | spinlock_t auth_lock; |
| 32 | struct crypto_hash *auth; |
| 33 | struct crypto_ablkcipher *enc; |
| 34 | }; |
| 35 | |
| 36 | static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key, |
| 37 | unsigned int keylen) |
| 38 | { |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 39 | unsigned int authkeylen; |
Herbert Xu | e236d4a | 2007-11-22 23:11:53 +0800 | [diff] [blame] | 40 | unsigned int enckeylen; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 41 | struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); |
| 42 | struct crypto_hash *auth = ctx->auth; |
| 43 | struct crypto_ablkcipher *enc = ctx->enc; |
Herbert Xu | e236d4a | 2007-11-22 23:11:53 +0800 | [diff] [blame] | 44 | struct rtattr *rta = (void *)key; |
| 45 | struct crypto_authenc_key_param *param; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 46 | int err = -EINVAL; |
| 47 | |
Herbert Xu | e236d4a | 2007-11-22 23:11:53 +0800 | [diff] [blame] | 48 | if (keylen < sizeof(*rta)) |
| 49 | goto badkey; |
| 50 | if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM) |
| 51 | goto badkey; |
| 52 | if (RTA_PAYLOAD(rta) < sizeof(*param)) |
| 53 | goto badkey; |
| 54 | |
| 55 | param = RTA_DATA(rta); |
| 56 | enckeylen = be32_to_cpu(param->enckeylen); |
| 57 | |
| 58 | key += RTA_ALIGN(rta->rta_len); |
| 59 | keylen -= RTA_ALIGN(rta->rta_len); |
| 60 | |
| 61 | if (keylen < enckeylen) |
| 62 | goto badkey; |
| 63 | |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 64 | authkeylen = keylen - enckeylen; |
| 65 | |
| 66 | crypto_hash_clear_flags(auth, CRYPTO_TFM_REQ_MASK); |
| 67 | crypto_hash_set_flags(auth, crypto_aead_get_flags(authenc) & |
| 68 | CRYPTO_TFM_REQ_MASK); |
| 69 | err = crypto_hash_setkey(auth, key, authkeylen); |
| 70 | crypto_aead_set_flags(authenc, crypto_hash_get_flags(auth) & |
| 71 | CRYPTO_TFM_RES_MASK); |
| 72 | |
| 73 | if (err) |
| 74 | goto out; |
| 75 | |
| 76 | crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK); |
| 77 | crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) & |
| 78 | CRYPTO_TFM_REQ_MASK); |
| 79 | err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen); |
| 80 | crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) & |
| 81 | CRYPTO_TFM_RES_MASK); |
| 82 | |
| 83 | out: |
| 84 | return err; |
Herbert Xu | e236d4a | 2007-11-22 23:11:53 +0800 | [diff] [blame] | 85 | |
| 86 | badkey: |
| 87 | crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN); |
| 88 | goto out; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 89 | } |
| 90 | |
| 91 | static int crypto_authenc_hash(struct aead_request *req) |
| 92 | { |
| 93 | struct crypto_aead *authenc = crypto_aead_reqtfm(req); |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 94 | struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); |
| 95 | struct crypto_hash *auth = ctx->auth; |
| 96 | struct hash_desc desc = { |
| 97 | .tfm = auth, |
| 98 | }; |
| 99 | u8 *hash = aead_request_ctx(req); |
Herbert Xu | f347c4f | 2007-10-11 16:45:17 +0800 | [diff] [blame] | 100 | struct scatterlist *dst = req->dst; |
| 101 | unsigned int cryptlen = req->cryptlen; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 102 | int err; |
| 103 | |
| 104 | hash = (u8 *)ALIGN((unsigned long)hash + crypto_hash_alignmask(auth), |
| 105 | crypto_hash_alignmask(auth) + 1); |
| 106 | |
| 107 | spin_lock_bh(&ctx->auth_lock); |
| 108 | err = crypto_hash_init(&desc); |
| 109 | if (err) |
| 110 | goto auth_unlock; |
| 111 | |
| 112 | err = crypto_hash_update(&desc, req->assoc, req->assoclen); |
| 113 | if (err) |
| 114 | goto auth_unlock; |
| 115 | |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 116 | err = crypto_hash_update(&desc, dst, cryptlen); |
| 117 | if (err) |
| 118 | goto auth_unlock; |
| 119 | |
| 120 | err = crypto_hash_final(&desc, hash); |
| 121 | auth_unlock: |
| 122 | spin_unlock_bh(&ctx->auth_lock); |
| 123 | |
| 124 | if (err) |
| 125 | return err; |
| 126 | |
Herbert Xu | 7ba683a | 2007-12-02 18:49:21 +1100 | [diff] [blame] | 127 | scatterwalk_map_and_copy(hash, dst, cryptlen, |
| 128 | crypto_aead_authsize(authenc), 1); |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 129 | return 0; |
| 130 | } |
| 131 | |
| 132 | static void crypto_authenc_encrypt_done(struct crypto_async_request *req, |
| 133 | int err) |
| 134 | { |
| 135 | if (!err) |
| 136 | err = crypto_authenc_hash(req->data); |
| 137 | |
| 138 | aead_request_complete(req->data, err); |
| 139 | } |
| 140 | |
| 141 | static int crypto_authenc_encrypt(struct aead_request *req) |
| 142 | { |
| 143 | struct crypto_aead *authenc = crypto_aead_reqtfm(req); |
| 144 | struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); |
| 145 | struct ablkcipher_request *abreq = aead_request_ctx(req); |
| 146 | int err; |
| 147 | |
| 148 | ablkcipher_request_set_tfm(abreq, ctx->enc); |
| 149 | ablkcipher_request_set_callback(abreq, aead_request_flags(req), |
| 150 | crypto_authenc_encrypt_done, req); |
| 151 | ablkcipher_request_set_crypt(abreq, req->src, req->dst, req->cryptlen, |
| 152 | req->iv); |
| 153 | |
| 154 | err = crypto_ablkcipher_encrypt(abreq); |
| 155 | if (err) |
| 156 | return err; |
| 157 | |
| 158 | return crypto_authenc_hash(req); |
| 159 | } |
| 160 | |
Herbert Xu | 481f34a | 2007-12-04 20:04:21 +1100 | [diff] [blame^] | 161 | static int crypto_authenc_verify(struct aead_request *req, |
| 162 | unsigned int cryptlen) |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 163 | { |
| 164 | struct crypto_aead *authenc = crypto_aead_reqtfm(req); |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 165 | struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); |
| 166 | struct crypto_hash *auth = ctx->auth; |
| 167 | struct hash_desc desc = { |
| 168 | .tfm = auth, |
| 169 | .flags = aead_request_flags(req), |
| 170 | }; |
| 171 | u8 *ohash = aead_request_ctx(req); |
| 172 | u8 *ihash; |
Herbert Xu | f347c4f | 2007-10-11 16:45:17 +0800 | [diff] [blame] | 173 | struct scatterlist *src = req->src; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 174 | unsigned int authsize; |
| 175 | int err; |
| 176 | |
| 177 | ohash = (u8 *)ALIGN((unsigned long)ohash + crypto_hash_alignmask(auth), |
| 178 | crypto_hash_alignmask(auth) + 1); |
| 179 | ihash = ohash + crypto_hash_digestsize(auth); |
| 180 | |
| 181 | spin_lock_bh(&ctx->auth_lock); |
| 182 | err = crypto_hash_init(&desc); |
| 183 | if (err) |
| 184 | goto auth_unlock; |
| 185 | |
| 186 | err = crypto_hash_update(&desc, req->assoc, req->assoclen); |
| 187 | if (err) |
| 188 | goto auth_unlock; |
| 189 | |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 190 | err = crypto_hash_update(&desc, src, cryptlen); |
| 191 | if (err) |
| 192 | goto auth_unlock; |
| 193 | |
| 194 | err = crypto_hash_final(&desc, ohash); |
| 195 | auth_unlock: |
| 196 | spin_unlock_bh(&ctx->auth_lock); |
| 197 | |
| 198 | if (err) |
| 199 | return err; |
| 200 | |
Herbert Xu | 7ba683a | 2007-12-02 18:49:21 +1100 | [diff] [blame] | 201 | authsize = crypto_aead_authsize(authenc); |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 202 | scatterwalk_map_and_copy(ihash, src, cryptlen, authsize, 0); |
| 203 | return memcmp(ihash, ohash, authsize) ? -EINVAL : 0; |
| 204 | } |
| 205 | |
| 206 | static void crypto_authenc_decrypt_done(struct crypto_async_request *req, |
| 207 | int err) |
| 208 | { |
| 209 | aead_request_complete(req->data, err); |
| 210 | } |
| 211 | |
| 212 | static int crypto_authenc_decrypt(struct aead_request *req) |
| 213 | { |
| 214 | struct crypto_aead *authenc = crypto_aead_reqtfm(req); |
| 215 | struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); |
| 216 | struct ablkcipher_request *abreq = aead_request_ctx(req); |
Herbert Xu | 481f34a | 2007-12-04 20:04:21 +1100 | [diff] [blame^] | 217 | unsigned int cryptlen = req->cryptlen; |
| 218 | unsigned int authsize = crypto_aead_authsize(authenc); |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 219 | int err; |
| 220 | |
Herbert Xu | 481f34a | 2007-12-04 20:04:21 +1100 | [diff] [blame^] | 221 | if (cryptlen < authsize) |
| 222 | return -EINVAL; |
| 223 | cryptlen -= authsize; |
| 224 | |
| 225 | err = crypto_authenc_verify(req, cryptlen); |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 226 | if (err) |
| 227 | return err; |
| 228 | |
| 229 | ablkcipher_request_set_tfm(abreq, ctx->enc); |
| 230 | ablkcipher_request_set_callback(abreq, aead_request_flags(req), |
| 231 | crypto_authenc_decrypt_done, req); |
Herbert Xu | 481f34a | 2007-12-04 20:04:21 +1100 | [diff] [blame^] | 232 | ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 233 | req->iv); |
| 234 | |
| 235 | return crypto_ablkcipher_decrypt(abreq); |
| 236 | } |
| 237 | |
| 238 | static int crypto_authenc_init_tfm(struct crypto_tfm *tfm) |
| 239 | { |
| 240 | struct crypto_instance *inst = (void *)tfm->__crt_alg; |
| 241 | struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst); |
| 242 | struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm); |
| 243 | struct crypto_hash *auth; |
| 244 | struct crypto_ablkcipher *enc; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 245 | int err; |
| 246 | |
| 247 | auth = crypto_spawn_hash(&ictx->auth); |
| 248 | if (IS_ERR(auth)) |
| 249 | return PTR_ERR(auth); |
| 250 | |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 251 | enc = crypto_spawn_ablkcipher(&ictx->enc); |
| 252 | err = PTR_ERR(enc); |
| 253 | if (IS_ERR(enc)) |
| 254 | goto err_free_hash; |
| 255 | |
| 256 | ctx->auth = auth; |
| 257 | ctx->enc = enc; |
| 258 | tfm->crt_aead.reqsize = max_t(unsigned int, |
| 259 | (crypto_hash_alignmask(auth) & |
| 260 | ~(crypto_tfm_ctx_alignment() - 1)) + |
Herbert Xu | 7ba683a | 2007-12-02 18:49:21 +1100 | [diff] [blame] | 261 | crypto_hash_digestsize(auth) * 2, |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 262 | sizeof(struct ablkcipher_request) + |
| 263 | crypto_ablkcipher_reqsize(enc)); |
| 264 | |
| 265 | spin_lock_init(&ctx->auth_lock); |
| 266 | |
| 267 | return 0; |
| 268 | |
| 269 | err_free_hash: |
| 270 | crypto_free_hash(auth); |
| 271 | return err; |
| 272 | } |
| 273 | |
| 274 | static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm) |
| 275 | { |
| 276 | struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm); |
| 277 | |
| 278 | crypto_free_hash(ctx->auth); |
| 279 | crypto_free_ablkcipher(ctx->enc); |
| 280 | } |
| 281 | |
| 282 | static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb) |
| 283 | { |
| 284 | struct crypto_instance *inst; |
| 285 | struct crypto_alg *auth; |
| 286 | struct crypto_alg *enc; |
| 287 | struct authenc_instance_ctx *ctx; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 288 | int err; |
| 289 | |
| 290 | err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD); |
| 291 | if (err) |
| 292 | return ERR_PTR(err); |
| 293 | |
| 294 | auth = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH, |
| 295 | CRYPTO_ALG_TYPE_HASH_MASK); |
| 296 | if (IS_ERR(auth)) |
| 297 | return ERR_PTR(PTR_ERR(auth)); |
| 298 | |
Herbert Xu | 7ba683a | 2007-12-02 18:49:21 +1100 | [diff] [blame] | 299 | enc = crypto_attr_alg(tb[2], CRYPTO_ALG_TYPE_BLKCIPHER, |
Herbert Xu | 332f884 | 2007-11-15 22:36:07 +0800 | [diff] [blame] | 300 | CRYPTO_ALG_TYPE_BLKCIPHER_MASK); |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 301 | inst = ERR_PTR(PTR_ERR(enc)); |
| 302 | if (IS_ERR(enc)) |
| 303 | goto out_put_auth; |
| 304 | |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 305 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); |
| 306 | err = -ENOMEM; |
| 307 | if (!inst) |
| 308 | goto out_put_enc; |
| 309 | |
| 310 | err = -ENAMETOOLONG; |
| 311 | if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, |
Herbert Xu | e236d4a | 2007-11-22 23:11:53 +0800 | [diff] [blame] | 312 | "authenc(%s,%s)", auth->cra_name, enc->cra_name) >= |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 313 | CRYPTO_MAX_ALG_NAME) |
| 314 | goto err_free_inst; |
| 315 | |
Herbert Xu | e236d4a | 2007-11-22 23:11:53 +0800 | [diff] [blame] | 316 | if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, |
| 317 | "authenc(%s,%s)", auth->cra_driver_name, |
| 318 | enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) |
| 319 | goto err_free_inst; |
| 320 | |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 321 | ctx = crypto_instance_ctx(inst); |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 322 | |
| 323 | err = crypto_init_spawn(&ctx->auth, auth, inst, CRYPTO_ALG_TYPE_MASK); |
| 324 | if (err) |
| 325 | goto err_free_inst; |
| 326 | |
| 327 | err = crypto_init_spawn(&ctx->enc, enc, inst, CRYPTO_ALG_TYPE_MASK); |
| 328 | if (err) |
| 329 | goto err_drop_auth; |
| 330 | |
| 331 | inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC; |
| 332 | inst->alg.cra_priority = enc->cra_priority * 10 + auth->cra_priority; |
| 333 | inst->alg.cra_blocksize = enc->cra_blocksize; |
Herbert Xu | e29bc6a | 2007-11-22 22:46:40 +0800 | [diff] [blame] | 334 | inst->alg.cra_alignmask = auth->cra_alignmask | enc->cra_alignmask; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 335 | inst->alg.cra_type = &crypto_aead_type; |
| 336 | |
| 337 | inst->alg.cra_aead.ivsize = enc->cra_blkcipher.ivsize; |
Herbert Xu | 7ba683a | 2007-12-02 18:49:21 +1100 | [diff] [blame] | 338 | inst->alg.cra_aead.maxauthsize = auth->cra_type == &crypto_hash_type ? |
| 339 | auth->cra_hash.digestsize : |
| 340 | auth->cra_digest.dia_digestsize; |
Herbert Xu | 3c09f17 | 2007-08-30 16:24:15 +0800 | [diff] [blame] | 341 | |
| 342 | inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx); |
| 343 | |
| 344 | inst->alg.cra_init = crypto_authenc_init_tfm; |
| 345 | inst->alg.cra_exit = crypto_authenc_exit_tfm; |
| 346 | |
| 347 | inst->alg.cra_aead.setkey = crypto_authenc_setkey; |
| 348 | inst->alg.cra_aead.encrypt = crypto_authenc_encrypt; |
| 349 | inst->alg.cra_aead.decrypt = crypto_authenc_decrypt; |
| 350 | |
| 351 | out: |
| 352 | crypto_mod_put(enc); |
| 353 | out_put_auth: |
| 354 | crypto_mod_put(auth); |
| 355 | return inst; |
| 356 | |
| 357 | err_drop_auth: |
| 358 | crypto_drop_spawn(&ctx->auth); |
| 359 | err_free_inst: |
| 360 | kfree(inst); |
| 361 | out_put_enc: |
| 362 | inst = ERR_PTR(err); |
| 363 | goto out; |
| 364 | } |
| 365 | |
| 366 | static void crypto_authenc_free(struct crypto_instance *inst) |
| 367 | { |
| 368 | struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst); |
| 369 | |
| 370 | crypto_drop_spawn(&ctx->enc); |
| 371 | crypto_drop_spawn(&ctx->auth); |
| 372 | kfree(inst); |
| 373 | } |
| 374 | |
| 375 | static struct crypto_template crypto_authenc_tmpl = { |
| 376 | .name = "authenc", |
| 377 | .alloc = crypto_authenc_alloc, |
| 378 | .free = crypto_authenc_free, |
| 379 | .module = THIS_MODULE, |
| 380 | }; |
| 381 | |
| 382 | static int __init crypto_authenc_module_init(void) |
| 383 | { |
| 384 | return crypto_register_template(&crypto_authenc_tmpl); |
| 385 | } |
| 386 | |
| 387 | static void __exit crypto_authenc_module_exit(void) |
| 388 | { |
| 389 | crypto_unregister_template(&crypto_authenc_tmpl); |
| 390 | } |
| 391 | |
| 392 | module_init(crypto_authenc_module_init); |
| 393 | module_exit(crypto_authenc_module_exit); |
| 394 | |
| 395 | MODULE_LICENSE("GPL"); |
| 396 | MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec"); |