6650c4de68
We avoid various VLAs[1] by using constant expressions for block size and alignment mask. [1] http://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
119 lines
3.3 KiB
C
119 lines
3.3 KiB
C
/*
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* Cryptographic API.
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*
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* Cipher operations.
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*
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* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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* Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#include <crypto/algapi.h>
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#include <linux/kernel.h>
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#include <linux/crypto.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include "internal.h"
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static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
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unsigned int keylen)
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{
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struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
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unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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int ret;
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u8 *buffer, *alignbuffer;
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unsigned long absize;
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absize = keylen + alignmask;
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buffer = kmalloc(absize, GFP_ATOMIC);
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if (!buffer)
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return -ENOMEM;
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alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
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memcpy(alignbuffer, key, keylen);
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ret = cia->cia_setkey(tfm, alignbuffer, keylen);
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memset(alignbuffer, 0, keylen);
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kfree(buffer);
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return ret;
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}
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static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
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{
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struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
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unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
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if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
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tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
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return -EINVAL;
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}
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if ((unsigned long)key & alignmask)
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return setkey_unaligned(tfm, key, keylen);
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return cia->cia_setkey(tfm, key, keylen);
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}
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static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
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const u8 *),
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struct crypto_tfm *tfm,
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u8 *dst, const u8 *src)
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{
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unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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unsigned int size = crypto_tfm_alg_blocksize(tfm);
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u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
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u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
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memcpy(tmp, src, size);
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fn(tfm, tmp, tmp);
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memcpy(dst, tmp, size);
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}
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static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
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u8 *dst, const u8 *src)
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{
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unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
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if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
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cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
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return;
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}
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cipher->cia_encrypt(tfm, dst, src);
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}
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static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
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u8 *dst, const u8 *src)
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{
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unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
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if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
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cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
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return;
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}
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cipher->cia_decrypt(tfm, dst, src);
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}
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int crypto_init_cipher_ops(struct crypto_tfm *tfm)
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{
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struct cipher_tfm *ops = &tfm->crt_cipher;
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struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
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ops->cit_setkey = setkey;
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ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
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cipher_encrypt_unaligned : cipher->cia_encrypt;
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ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
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cipher_decrypt_unaligned : cipher->cia_decrypt;
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return 0;
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}
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