1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Cryptographic API. 4 * 5 * Single-block cipher operations. 6 * 7 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> 8 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au> 9 */ 10 11 #include <crypto/algapi.h> 12 #include <linux/kernel.h> 13 #include <linux/crypto.h> 14 #include <linux/errno.h> 15 #include <linux/slab.h> 16 #include <linux/string.h> 17 #include "internal.h" 18 19 static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key, 20 unsigned int keylen) 21 { 22 struct cipher_alg *cia = crypto_cipher_alg(tfm); 23 unsigned long alignmask = crypto_cipher_alignmask(tfm); 24 int ret; 25 u8 *buffer, *alignbuffer; 26 unsigned long absize; 27 28 absize = keylen + alignmask; 29 buffer = kmalloc(absize, GFP_ATOMIC); 30 if (!buffer) 31 return -ENOMEM; 32 33 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 34 memcpy(alignbuffer, key, keylen); 35 ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen); 36 memset(alignbuffer, 0, keylen); 37 kfree(buffer); 38 return ret; 39 40 } 41 42 int crypto_cipher_setkey(struct crypto_cipher *tfm, 43 const u8 *key, unsigned int keylen) 44 { 45 struct cipher_alg *cia = crypto_cipher_alg(tfm); 46 unsigned long alignmask = crypto_cipher_alignmask(tfm); 47 48 crypto_cipher_clear_flags(tfm, CRYPTO_TFM_RES_MASK); 49 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) { 50 crypto_cipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 51 return -EINVAL; 52 } 53 54 if ((unsigned long)key & alignmask) 55 return setkey_unaligned(tfm, key, keylen); 56 57 return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen); 58 } 59 EXPORT_SYMBOL_GPL(crypto_cipher_setkey); 60 61 static inline void cipher_crypt_one(struct crypto_cipher *tfm, 62 u8 *dst, const u8 *src, bool enc) 63 { 64 unsigned long alignmask = crypto_cipher_alignmask(tfm); 65 struct cipher_alg *cia = crypto_cipher_alg(tfm); 66 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = 67 enc ? cia->cia_encrypt : cia->cia_decrypt; 68 69 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { 70 unsigned int bs = crypto_cipher_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, bs); 75 fn(crypto_cipher_tfm(tfm), tmp, tmp); 76 memcpy(dst, tmp, bs); 77 } else { 78 fn(crypto_cipher_tfm(tfm), dst, src); 79 } 80 } 81 82 void crypto_cipher_encrypt_one(struct crypto_cipher *tfm, 83 u8 *dst, const u8 *src) 84 { 85 cipher_crypt_one(tfm, dst, src, true); 86 } 87 EXPORT_SYMBOL_GPL(crypto_cipher_encrypt_one); 88 89 void crypto_cipher_decrypt_one(struct crypto_cipher *tfm, 90 u8 *dst, const u8 *src) 91 { 92 cipher_crypt_one(tfm, dst, src, false); 93 } 94 EXPORT_SYMBOL_GPL(crypto_cipher_decrypt_one); 95