1 /* 2 * Cryptographic API. 3 * 4 * Cipher operations. 5 * 6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> 7 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au> 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License as published by the Free 11 * Software Foundation; either version 2 of the License, or (at your option) 12 * any later version. 13 * 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/crypto.h> 18 #include <linux/errno.h> 19 #include <linux/scatterlist.h> 20 #include <linux/string.h> 21 #include "internal.h" 22 23 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) 24 { 25 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; 26 27 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 28 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) { 29 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 30 return -EINVAL; 31 } else 32 return cia->cia_setkey(tfm, key, keylen); 33 } 34 35 static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *, 36 const u8 *), 37 struct crypto_tfm *tfm, 38 u8 *dst, const u8 *src) 39 { 40 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 41 unsigned int size = crypto_tfm_alg_blocksize(tfm); 42 u8 buffer[size + alignmask]; 43 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 44 45 memcpy(tmp, src, size); 46 fn(tfm, tmp, tmp); 47 memcpy(dst, tmp, size); 48 } 49 50 static void cipher_encrypt_unaligned(struct crypto_tfm *tfm, 51 u8 *dst, const u8 *src) 52 { 53 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 54 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 55 56 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { 57 cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src); 58 return; 59 } 60 61 cipher->cia_encrypt(tfm, dst, src); 62 } 63 64 static void cipher_decrypt_unaligned(struct crypto_tfm *tfm, 65 u8 *dst, const u8 *src) 66 { 67 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 68 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 69 70 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { 71 cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src); 72 return; 73 } 74 75 cipher->cia_decrypt(tfm, dst, src); 76 } 77 78 int crypto_init_cipher_ops(struct crypto_tfm *tfm) 79 { 80 struct cipher_tfm *ops = &tfm->crt_cipher; 81 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 82 83 ops->cit_setkey = setkey; 84 ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ? 85 cipher_encrypt_unaligned : cipher->cia_encrypt; 86 ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ? 87 cipher_decrypt_unaligned : cipher->cia_decrypt; 88 89 return 0; 90 } 91 92 void crypto_exit_cipher_ops(struct crypto_tfm *tfm) 93 { 94 } 95