/* * 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");