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 <crypto/algapi.h> 17 #include <linux/kernel.h> 18 #include <linux/crypto.h> 19 #include <linux/errno.h> 20 #include <linux/slab.h> 21 #include <linux/string.h> 22 #include "internal.h" 23 24 static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key, 25 unsigned int keylen) 26 { 27 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; 28 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 29 int ret; 30 u8 *buffer, *alignbuffer; 31 unsigned long absize; 32 33 absize = keylen + alignmask; 34 buffer = kmalloc(absize, GFP_ATOMIC); 35 if (!buffer) 36 return -ENOMEM; 37 38 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 39 memcpy(alignbuffer, key, keylen); 40 ret = cia->cia_setkey(tfm, alignbuffer, keylen); 41 memset(alignbuffer, 0, keylen); 42 kfree(buffer); 43 return ret; 44 45 } 46 47 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) 48 { 49 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; 50 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 51 52 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 53 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) { 54 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 55 return -EINVAL; 56 } 57 58 if ((unsigned long)key & alignmask) 59 return setkey_unaligned(tfm, key, keylen); 60 61 return cia->cia_setkey(tfm, key, keylen); 62 } 63 64 static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *, 65 const u8 *), 66 struct crypto_tfm *tfm, 67 u8 *dst, const u8 *src) 68 { 69 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 70 unsigned int size = crypto_tfm_alg_blocksize(tfm); 71 u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK]; 72 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 73 74 memcpy(tmp, src, size); 75 fn(tfm, tmp, tmp); 76 memcpy(dst, tmp, size); 77 } 78 79 static void cipher_encrypt_unaligned(struct crypto_tfm *tfm, 80 u8 *dst, const u8 *src) 81 { 82 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 83 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 84 85 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { 86 cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src); 87 return; 88 } 89 90 cipher->cia_encrypt(tfm, dst, src); 91 } 92 93 static void cipher_decrypt_unaligned(struct crypto_tfm *tfm, 94 u8 *dst, const u8 *src) 95 { 96 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 97 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 98 99 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { 100 cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src); 101 return; 102 } 103 104 cipher->cia_decrypt(tfm, dst, src); 105 } 106 107 int crypto_init_cipher_ops(struct crypto_tfm *tfm) 108 { 109 struct cipher_tfm *ops = &tfm->crt_cipher; 110 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 111 112 ops->cit_setkey = setkey; 113 ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ? 114 cipher_encrypt_unaligned : cipher->cia_encrypt; 115 ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ? 116 cipher_decrypt_unaligned : cipher->cia_decrypt; 117 118 return 0; 119 } 120