1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Cryptographic API. 4 * 5 * 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_tfm *tfm, const u8 *key, 20 unsigned int keylen) 21 { 22 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; 23 unsigned long alignmask = crypto_tfm_alg_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(tfm, alignbuffer, keylen); 36 memset(alignbuffer, 0, keylen); 37 kfree(buffer); 38 return ret; 39 40 } 41 42 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) 43 { 44 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; 45 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 46 47 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 48 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) { 49 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 50 return -EINVAL; 51 } 52 53 if ((unsigned long)key & alignmask) 54 return setkey_unaligned(tfm, key, keylen); 55 56 return cia->cia_setkey(tfm, key, keylen); 57 } 58 59 static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *, 60 const u8 *), 61 struct crypto_tfm *tfm, 62 u8 *dst, const u8 *src) 63 { 64 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 65 unsigned int size = crypto_tfm_alg_blocksize(tfm); 66 u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK]; 67 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 68 69 memcpy(tmp, src, size); 70 fn(tfm, tmp, tmp); 71 memcpy(dst, tmp, size); 72 } 73 74 static void cipher_encrypt_unaligned(struct crypto_tfm *tfm, 75 u8 *dst, const u8 *src) 76 { 77 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 78 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 79 80 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { 81 cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src); 82 return; 83 } 84 85 cipher->cia_encrypt(tfm, dst, src); 86 } 87 88 static void cipher_decrypt_unaligned(struct crypto_tfm *tfm, 89 u8 *dst, const u8 *src) 90 { 91 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 92 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 93 94 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) { 95 cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src); 96 return; 97 } 98 99 cipher->cia_decrypt(tfm, dst, src); 100 } 101 102 int crypto_init_cipher_ops(struct crypto_tfm *tfm) 103 { 104 struct cipher_tfm *ops = &tfm->crt_cipher; 105 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 106 107 ops->cit_setkey = setkey; 108 ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ? 109 cipher_encrypt_unaligned : cipher->cia_encrypt; 110 ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ? 111 cipher_decrypt_unaligned : cipher->cia_decrypt; 112 113 return 0; 114 } 115