diff options
Diffstat (limited to 'crypto/ofb.c')
| -rw-r--r-- | crypto/ofb.c | 225 |
1 files changed, 0 insertions, 225 deletions
diff --git a/crypto/ofb.c b/crypto/ofb.c deleted file mode 100644 index 886631708c5e..000000000000 --- a/crypto/ofb.c +++ /dev/null @@ -1,225 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 - -/* - * OFB: Output FeedBack mode - * - * Copyright (C) 2018 ARM Limited or its affiliates. - * All rights reserved. - * - * Based loosely on public domain code gleaned from libtomcrypt - * (https://github.com/libtom/libtomcrypt). - */ - -#include <crypto/algapi.h> -#include <crypto/internal/skcipher.h> -#include <linux/err.h> -#include <linux/init.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/scatterlist.h> -#include <linux/slab.h> - -struct crypto_ofb_ctx { - struct crypto_cipher *child; - int cnt; -}; - - -static int crypto_ofb_setkey(struct crypto_skcipher *parent, const u8 *key, - unsigned int keylen) -{ - struct crypto_ofb_ctx *ctx = crypto_skcipher_ctx(parent); - struct crypto_cipher *child = ctx->child; - int err; - - crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); - crypto_cipher_set_flags(child, crypto_skcipher_get_flags(parent) & - CRYPTO_TFM_REQ_MASK); - err = crypto_cipher_setkey(child, key, keylen); - crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(child) & - CRYPTO_TFM_RES_MASK); - return err; -} - -static int crypto_ofb_encrypt_segment(struct crypto_ofb_ctx *ctx, - struct skcipher_walk *walk, - struct crypto_cipher *tfm) -{ - int bsize = crypto_cipher_blocksize(tfm); - int nbytes = walk->nbytes; - - u8 *src = walk->src.virt.addr; - u8 *dst = walk->dst.virt.addr; - u8 *iv = walk->iv; - - do { - if (ctx->cnt == bsize) { - if (nbytes < bsize) - break; - crypto_cipher_encrypt_one(tfm, iv, iv); - ctx->cnt = 0; - } - *dst = *src ^ iv[ctx->cnt]; - src++; - dst++; - ctx->cnt++; - } while (--nbytes); - return nbytes; -} - -static int crypto_ofb_encrypt(struct skcipher_request *req) -{ - struct skcipher_walk walk; - struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); - unsigned int bsize; - struct crypto_ofb_ctx *ctx = crypto_skcipher_ctx(tfm); - struct crypto_cipher *child = ctx->child; - int ret = 0; - - bsize = crypto_cipher_blocksize(child); - ctx->cnt = bsize; - - ret = skcipher_walk_virt(&walk, req, false); - - while (walk.nbytes) { - ret = crypto_ofb_encrypt_segment(ctx, &walk, child); - ret = skcipher_walk_done(&walk, ret); - } - - return ret; -} - -/* OFB encrypt and decrypt are identical */ -static int crypto_ofb_decrypt(struct skcipher_request *req) -{ - return crypto_ofb_encrypt(req); -} - -static int crypto_ofb_init_tfm(struct crypto_skcipher *tfm) -{ - struct skcipher_instance *inst = skcipher_alg_instance(tfm); - struct crypto_spawn *spawn = skcipher_instance_ctx(inst); - struct crypto_ofb_ctx *ctx = crypto_skcipher_ctx(tfm); - struct crypto_cipher *cipher; - - cipher = crypto_spawn_cipher(spawn); - if (IS_ERR(cipher)) - return PTR_ERR(cipher); - - ctx->child = cipher; - return 0; -} - -static void crypto_ofb_exit_tfm(struct crypto_skcipher *tfm) -{ - struct crypto_ofb_ctx *ctx = crypto_skcipher_ctx(tfm); - - crypto_free_cipher(ctx->child); -} - -static void crypto_ofb_free(struct skcipher_instance *inst) -{ - crypto_drop_skcipher(skcipher_instance_ctx(inst)); - kfree(inst); -} - -static int crypto_ofb_create(struct crypto_template *tmpl, struct rtattr **tb) -{ - struct skcipher_instance *inst; - struct crypto_attr_type *algt; - struct crypto_spawn *spawn; - struct crypto_alg *alg; - u32 mask; - int err; - - err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER); - if (err) - return err; - - inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); - if (!inst) - return -ENOMEM; - - algt = crypto_get_attr_type(tb); - err = PTR_ERR(algt); - if (IS_ERR(algt)) - goto err_free_inst; - - mask = CRYPTO_ALG_TYPE_MASK | - crypto_requires_off(algt->type, algt->mask, - CRYPTO_ALG_NEED_FALLBACK); - - alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask); - err = PTR_ERR(alg); - if (IS_ERR(alg)) - goto err_free_inst; - - spawn = skcipher_instance_ctx(inst); - err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst), - CRYPTO_ALG_TYPE_MASK); - crypto_mod_put(alg); - if (err) - goto err_free_inst; - - err = crypto_inst_setname(skcipher_crypto_instance(inst), "ofb", alg); - if (err) - goto err_drop_spawn; - - inst->alg.base.cra_priority = alg->cra_priority; - inst->alg.base.cra_blocksize = alg->cra_blocksize; - inst->alg.base.cra_alignmask = alg->cra_alignmask; - - /* We access the data as u32s when xoring. */ - inst->alg.base.cra_alignmask |= __alignof__(u32) - 1; - - inst->alg.ivsize = alg->cra_blocksize; - inst->alg.min_keysize = alg->cra_cipher.cia_min_keysize; - inst->alg.max_keysize = alg->cra_cipher.cia_max_keysize; - - inst->alg.base.cra_ctxsize = sizeof(struct crypto_ofb_ctx); - - inst->alg.init = crypto_ofb_init_tfm; - inst->alg.exit = crypto_ofb_exit_tfm; - - inst->alg.setkey = crypto_ofb_setkey; - inst->alg.encrypt = crypto_ofb_encrypt; - inst->alg.decrypt = crypto_ofb_decrypt; - - inst->free = crypto_ofb_free; - - err = skcipher_register_instance(tmpl, inst); - if (err) - goto err_drop_spawn; - -out: - return err; - -err_drop_spawn: - crypto_drop_spawn(spawn); -err_free_inst: - kfree(inst); - goto out; -} - -static struct crypto_template crypto_ofb_tmpl = { - .name = "ofb", - .create = crypto_ofb_create, - .module = THIS_MODULE, -}; - -static int __init crypto_ofb_module_init(void) -{ - return crypto_register_template(&crypto_ofb_tmpl); -} - -static void __exit crypto_ofb_module_exit(void) -{ - crypto_unregister_template(&crypto_ofb_tmpl); -} - -module_init(crypto_ofb_module_init); -module_exit(crypto_ofb_module_exit); - -MODULE_LICENSE("GPL"); -MODULE_DESCRIPTION("OFB block cipher algorithm"); -MODULE_ALIAS_CRYPTO("ofb"); |