diff options
Diffstat (limited to 'crypto/ecb.c')
| -rw-r--r-- | crypto/ecb.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/crypto/ecb.c b/crypto/ecb.c new file mode 100644 index 0000000..f239aa9 --- /dev/null +++ b/crypto/ecb.c @@ -0,0 +1,181 @@ +/* + * ECB: Electronic CodeBook mode + * + * Copyright (c) 2006 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/algapi.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_ecb_ctx { + struct crypto_cipher *child; +}; + +static int crypto_ecb_setkey(struct crypto_tfm *parent, const u8 *key, + unsigned int keylen) +{ + struct crypto_ecb_ctx *ctx = crypto_tfm_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_tfm_get_flags(parent) & + CRYPTO_TFM_REQ_MASK); + err = crypto_cipher_setkey(child, key, keylen); + crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) & + CRYPTO_TFM_RES_MASK); + return err; +} + +static int crypto_ecb_crypt(struct blkcipher_desc *desc, + struct blkcipher_walk *walk, + struct crypto_cipher *tfm, + void (*fn)(struct crypto_tfm *, u8 *, const u8 *)) +{ + int bsize = crypto_cipher_blocksize(tfm); + unsigned int nbytes; + int err; + + err = blkcipher_walk_virt(desc, walk); + + while ((nbytes = walk->nbytes)) { + u8 *wsrc = walk->src.virt.addr; + u8 *wdst = walk->dst.virt.addr; + + do { + fn(crypto_cipher_tfm(tfm), wdst, wsrc); + + wsrc += bsize; + wdst += bsize; + } while ((nbytes -= bsize) >= bsize); + + err = blkcipher_walk_done(desc, walk, nbytes); + } + + return err; +} + +static int crypto_ecb_encrypt(struct blkcipher_desc *desc, + struct scatterlist *dst, struct scatterlist *src, + unsigned int nbytes) +{ + struct blkcipher_walk walk; + struct crypto_blkcipher *tfm = desc->tfm; + struct crypto_ecb_ctx *ctx = crypto_blkcipher_ctx(tfm); + struct crypto_cipher *child = ctx->child; + + blkcipher_walk_init(&walk, dst, src, nbytes); + return crypto_ecb_crypt(desc, &walk, child, + crypto_cipher_alg(child)->cia_encrypt); +} + +static int crypto_ecb_decrypt(struct blkcipher_desc *desc, + struct scatterlist *dst, struct scatterlist *src, + unsigned int nbytes) +{ + struct blkcipher_walk walk; + struct crypto_blkcipher *tfm = desc->tfm; + struct crypto_ecb_ctx *ctx = crypto_blkcipher_ctx(tfm); + struct crypto_cipher *child = ctx->child; + + blkcipher_walk_init(&walk, dst, src, nbytes); + return crypto_ecb_crypt(desc, &walk, child, + crypto_cipher_alg(child)->cia_decrypt); +} + +static int crypto_ecb_init_tfm(struct crypto_tfm *tfm) +{ + struct crypto_instance *inst = (void *)tfm->__crt_alg; + struct crypto_spawn *spawn = crypto_instance_ctx(inst); + struct crypto_ecb_ctx *ctx = crypto_tfm_ctx(tfm); + + tfm = crypto_spawn_tfm(spawn); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + ctx->child = crypto_cipher_cast(tfm); + return 0; +} + +static void crypto_ecb_exit_tfm(struct crypto_tfm *tfm) +{ + struct crypto_ecb_ctx *ctx = crypto_tfm_ctx(tfm); + crypto_free_cipher(ctx->child); +} + +static struct crypto_instance *crypto_ecb_alloc(void *param, unsigned int len) +{ + struct crypto_instance *inst; + struct crypto_alg *alg; + + alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER, + CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC); + if (IS_ERR(alg)) + return ERR_PTR(PTR_ERR(alg)); + + inst = crypto_alloc_instance("ecb", alg); + if (IS_ERR(inst)) + goto out_put_alg; + + inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER; + inst->alg.cra_priority = alg->cra_priority; + inst->alg.cra_blocksize = alg->cra_blocksize; + inst->alg.cra_alignmask = alg->cra_alignmask; + inst->alg.cra_type = &crypto_blkcipher_type; + + inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize; + inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize; + + inst->alg.cra_ctxsize = sizeof(struct crypto_ecb_ctx); + + inst->alg.cra_init = crypto_ecb_init_tfm; + inst->alg.cra_exit = crypto_ecb_exit_tfm; + + inst->alg.cra_blkcipher.setkey = crypto_ecb_setkey; + inst->alg.cra_blkcipher.encrypt = crypto_ecb_encrypt; + inst->alg.cra_blkcipher.decrypt = crypto_ecb_decrypt; + +out_put_alg: + crypto_mod_put(alg); + return inst; +} + +static void crypto_ecb_free(struct crypto_instance *inst) +{ + crypto_drop_spawn(crypto_instance_ctx(inst)); + kfree(inst); +} + +static struct crypto_template crypto_ecb_tmpl = { + .name = "ecb", + .alloc = crypto_ecb_alloc, + .free = crypto_ecb_free, + .module = THIS_MODULE, +}; + +static int __init crypto_ecb_module_init(void) +{ + return crypto_register_template(&crypto_ecb_tmpl); +} + +static void __exit crypto_ecb_module_exit(void) +{ + crypto_unregister_template(&crypto_ecb_tmpl); +} + +module_init(crypto_ecb_module_init); +module_exit(crypto_ecb_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("ECB block cipher algorithm"); 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