/* * Cryptographic API. * * Cipher operations. * * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> * Copyright (c) 2005 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 <linux/kernel.h> #include <linux/crypto.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/string.h> #include "internal.h" static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) { struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); int ret; u8 *buffer, *alignbuffer; unsigned long absize; absize = keylen + alignmask; buffer = kmalloc(absize, GFP_ATOMIC); if (!buffer) return -ENOMEM; alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); memcpy(alignbuffer, key, keylen); ret = cia->cia_setkey(tfm, alignbuffer, keylen); memset(alignbuffer, 0, keylen); kfree(buffer); return ret; } static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) { struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) { tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; return -EINVAL; } if ((unsigned long)key & alignmask) return setkey_unaligned(tfm, key, keylen); return cia->cia_setkey(tfm, key, keylen); } static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *, const u8 *), struct crypto_tfm *tfm, u8 *dst, const u8 *src) { unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); unsigned int size = crypto_tfm_alg_blocksize(tfm); u8 buffer[size + alignmask]; u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); memcpy(tmp, src, size); fn(tfm, tmp, tmp); memcpy(dst, tmp, size); } static void cipher_encrypt_unaligned(struct crypto_tfm *tfm, u8 *dst, const u8 *src) { unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src); return; } cipher->cia_encrypt(tfm, dst, src); } static void cipher_decrypt_unaligned(struct crypto_tfm *tfm, u8 *dst, const u8 *src) { unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src); return; } cipher->cia_decrypt(tfm, dst, src); } int crypto_init_cipher_ops(struct crypto_tfm *tfm) { struct cipher_tfm *ops = &tfm->crt_cipher; struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; ops->cit_setkey = setkey; ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ? cipher_encrypt_unaligned : cipher->cia_encrypt; ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ? cipher_decrypt_unaligned : cipher->cia_decrypt; return 0; }