| /* |
| * Symmetric key cipher operations. |
| * |
| * Generic encrypt/decrypt wrapper for ciphers, handles operations across |
| * multiple page boundaries by using temporary blocks. In user context, |
| * the kernel is given a chance to schedule us once per page. |
| * |
| * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the Free |
| * Software Foundation; either version 2 of the License, or (at your option) |
| * any later version. |
| * |
| */ |
| |
| #include <crypto/internal/skcipher.h> |
| #include <linux/bug.h> |
| #include <linux/module.h> |
| |
| #include "internal.h" |
| |
| static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg) |
| { |
| if (alg->cra_type == &crypto_blkcipher_type) |
| return sizeof(struct crypto_blkcipher *); |
| |
| BUG_ON(alg->cra_type != &crypto_ablkcipher_type && |
| alg->cra_type != &crypto_givcipher_type); |
| |
| return sizeof(struct crypto_ablkcipher *); |
| } |
| |
| static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm, |
| const u8 *key, unsigned int keylen) |
| { |
| struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); |
| struct crypto_blkcipher *blkcipher = *ctx; |
| int err; |
| |
| crypto_blkcipher_clear_flags(blkcipher, ~0); |
| crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) & |
| CRYPTO_TFM_REQ_MASK); |
| err = crypto_blkcipher_setkey(blkcipher, key, keylen); |
| crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) & |
| CRYPTO_TFM_RES_MASK); |
| |
| return err; |
| } |
| |
| static int skcipher_crypt_blkcipher(struct skcipher_request *req, |
| int (*crypt)(struct blkcipher_desc *, |
| struct scatterlist *, |
| struct scatterlist *, |
| unsigned int)) |
| { |
| struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); |
| struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); |
| struct blkcipher_desc desc = { |
| .tfm = *ctx, |
| .info = req->iv, |
| .flags = req->base.flags, |
| }; |
| |
| |
| return crypt(&desc, req->dst, req->src, req->cryptlen); |
| } |
| |
| static int skcipher_encrypt_blkcipher(struct skcipher_request *req) |
| { |
| struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); |
| struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); |
| struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; |
| |
| return skcipher_crypt_blkcipher(req, alg->encrypt); |
| } |
| |
| static int skcipher_decrypt_blkcipher(struct skcipher_request *req) |
| { |
| struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); |
| struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); |
| struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; |
| |
| return skcipher_crypt_blkcipher(req, alg->decrypt); |
| } |
| |
| static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm) |
| { |
| struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); |
| |
| crypto_free_blkcipher(*ctx); |
| } |
| |
| static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm) |
| { |
| struct crypto_alg *calg = tfm->__crt_alg; |
| struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); |
| struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); |
| struct crypto_blkcipher *blkcipher; |
| struct crypto_tfm *btfm; |
| |
| if (!crypto_mod_get(calg)) |
| return -EAGAIN; |
| |
| btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER, |
| CRYPTO_ALG_TYPE_MASK); |
| if (IS_ERR(btfm)) { |
| crypto_mod_put(calg); |
| return PTR_ERR(btfm); |
| } |
| |
| blkcipher = __crypto_blkcipher_cast(btfm); |
| *ctx = blkcipher; |
| tfm->exit = crypto_exit_skcipher_ops_blkcipher; |
| |
| skcipher->setkey = skcipher_setkey_blkcipher; |
| skcipher->encrypt = skcipher_encrypt_blkcipher; |
| skcipher->decrypt = skcipher_decrypt_blkcipher; |
| |
| skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher); |
| skcipher->has_setkey = calg->cra_blkcipher.max_keysize; |
| |
| return 0; |
| } |
| |
| static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm, |
| const u8 *key, unsigned int keylen) |
| { |
| struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); |
| struct crypto_ablkcipher *ablkcipher = *ctx; |
| int err; |
| |
| crypto_ablkcipher_clear_flags(ablkcipher, ~0); |
| crypto_ablkcipher_set_flags(ablkcipher, |
| crypto_skcipher_get_flags(tfm) & |
| CRYPTO_TFM_REQ_MASK); |
| err = crypto_ablkcipher_setkey(ablkcipher, key, keylen); |
| crypto_skcipher_set_flags(tfm, |
| crypto_ablkcipher_get_flags(ablkcipher) & |
| CRYPTO_TFM_RES_MASK); |
| |
| return err; |
| } |
| |
| static int skcipher_crypt_ablkcipher(struct skcipher_request *req, |
| int (*crypt)(struct ablkcipher_request *)) |
| { |
| struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); |
| struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); |
| struct ablkcipher_request *subreq = skcipher_request_ctx(req); |
| |
| ablkcipher_request_set_tfm(subreq, *ctx); |
| ablkcipher_request_set_callback(subreq, skcipher_request_flags(req), |
| req->base.complete, req->base.data); |
| ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, |
| req->iv); |
| |
| return crypt(subreq); |
| } |
| |
| static int skcipher_encrypt_ablkcipher(struct skcipher_request *req) |
| { |
| struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); |
| struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); |
| struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; |
| |
| return skcipher_crypt_ablkcipher(req, alg->encrypt); |
| } |
| |
| static int skcipher_decrypt_ablkcipher(struct skcipher_request *req) |
| { |
| struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); |
| struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); |
| struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; |
| |
| return skcipher_crypt_ablkcipher(req, alg->decrypt); |
| } |
| |
| static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) |
| { |
| struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); |
| |
| crypto_free_ablkcipher(*ctx); |
| } |
| |
| static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) |
| { |
| struct crypto_alg *calg = tfm->__crt_alg; |
| struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); |
| struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); |
| struct crypto_ablkcipher *ablkcipher; |
| struct crypto_tfm *abtfm; |
| |
| if (!crypto_mod_get(calg)) |
| return -EAGAIN; |
| |
| abtfm = __crypto_alloc_tfm(calg, 0, 0); |
| if (IS_ERR(abtfm)) { |
| crypto_mod_put(calg); |
| return PTR_ERR(abtfm); |
| } |
| |
| ablkcipher = __crypto_ablkcipher_cast(abtfm); |
| *ctx = ablkcipher; |
| tfm->exit = crypto_exit_skcipher_ops_ablkcipher; |
| |
| skcipher->setkey = skcipher_setkey_ablkcipher; |
| skcipher->encrypt = skcipher_encrypt_ablkcipher; |
| skcipher->decrypt = skcipher_decrypt_ablkcipher; |
| |
| skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher); |
| skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) + |
| sizeof(struct ablkcipher_request); |
| skcipher->has_setkey = calg->cra_ablkcipher.max_keysize; |
| |
| return 0; |
| } |
| |
| static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) |
| { |
| if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type) |
| return crypto_init_skcipher_ops_blkcipher(tfm); |
| |
| BUG_ON(tfm->__crt_alg->cra_type != &crypto_ablkcipher_type && |
| tfm->__crt_alg->cra_type != &crypto_givcipher_type); |
| |
| return crypto_init_skcipher_ops_ablkcipher(tfm); |
| } |
| |
| static const struct crypto_type crypto_skcipher_type2 = { |
| .extsize = crypto_skcipher_extsize, |
| .init_tfm = crypto_skcipher_init_tfm, |
| .maskclear = ~CRYPTO_ALG_TYPE_MASK, |
| .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK, |
| .type = CRYPTO_ALG_TYPE_BLKCIPHER, |
| .tfmsize = offsetof(struct crypto_skcipher, base), |
| }; |
| |
| struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, |
| u32 type, u32 mask) |
| { |
| return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask); |
| } |
| EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("Symmetric key cipher type"); |