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 <crypto/internal/cipher.h>
13 #include <linux/kernel.h>
14 #include <linux/crypto.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 #include "internal.h"
19 
setkey_unaligned(struct crypto_cipher * tfm,const u8 * key,unsigned int keylen)20 static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key,
21 			    unsigned int keylen)
22 {
23 	struct cipher_alg *cia = crypto_cipher_alg(tfm);
24 	unsigned long alignmask = crypto_cipher_alignmask(tfm);
25 	int ret;
26 	u8 *buffer, *alignbuffer;
27 	unsigned long absize;
28 
29 	absize = keylen + alignmask;
30 	buffer = kmalloc(absize, GFP_ATOMIC);
31 	if (!buffer)
32 		return -ENOMEM;
33 
34 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
35 	memcpy(alignbuffer, key, keylen);
36 	ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen);
37 	memset(alignbuffer, 0, keylen);
38 	kfree(buffer);
39 	return ret;
40 
41 }
42 
crypto_cipher_setkey(struct crypto_cipher * tfm,const u8 * key,unsigned int keylen)43 int crypto_cipher_setkey(struct crypto_cipher *tfm,
44 			 const u8 *key, unsigned int keylen)
45 {
46 	struct cipher_alg *cia = crypto_cipher_alg(tfm);
47 	unsigned long alignmask = crypto_cipher_alignmask(tfm);
48 
49 	if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize)
50 		return -EINVAL;
51 
52 	if ((unsigned long)key & alignmask)
53 		return setkey_unaligned(tfm, key, keylen);
54 
55 	return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen);
56 }
57 EXPORT_SYMBOL_NS_GPL(crypto_cipher_setkey, CRYPTO_INTERNAL);
58 
cipher_crypt_one(struct crypto_cipher * tfm,u8 * dst,const u8 * src,bool enc)59 static inline void cipher_crypt_one(struct crypto_cipher *tfm,
60 				    u8 *dst, const u8 *src, bool enc)
61 {
62 	unsigned long alignmask = crypto_cipher_alignmask(tfm);
63 	struct cipher_alg *cia = crypto_cipher_alg(tfm);
64 	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
65 		enc ? cia->cia_encrypt : cia->cia_decrypt;
66 
67 	if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
68 		unsigned int bs = crypto_cipher_blocksize(tfm);
69 		u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
70 		u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
71 
72 		memcpy(tmp, src, bs);
73 		fn(crypto_cipher_tfm(tfm), tmp, tmp);
74 		memcpy(dst, tmp, bs);
75 	} else {
76 		fn(crypto_cipher_tfm(tfm), dst, src);
77 	}
78 }
79 
crypto_cipher_encrypt_one(struct crypto_cipher * tfm,u8 * dst,const u8 * src)80 void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
81 			       u8 *dst, const u8 *src)
82 {
83 	cipher_crypt_one(tfm, dst, src, true);
84 }
85 EXPORT_SYMBOL_NS_GPL(crypto_cipher_encrypt_one, CRYPTO_INTERNAL);
86 
crypto_cipher_decrypt_one(struct crypto_cipher * tfm,u8 * dst,const u8 * src)87 void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
88 			       u8 *dst, const u8 *src)
89 {
90 	cipher_crypt_one(tfm, dst, src, false);
91 }
92 EXPORT_SYMBOL_NS_GPL(crypto_cipher_decrypt_one, CRYPTO_INTERNAL);
93