| 1 | |
| 2 | |
| 3 | * Cryptographic API.
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| 4 | *
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| 5 | * Cipher operations.
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| 6 | *
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| 7 | * Copyright (c) 2002 James Morris <[email protected]>
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| 8 | * Copyright (c) 2005 Herbert Xu <[email protected]>
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| 9 |
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| 10 |
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| 11 | #include <crypto/algapi.h>
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| 12 | #include <linux/kernel.h>
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| 13 | #include <linux/crypto.h>
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| 14 | #include <linux/errno.h>
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| 15 | #include <linux/slab.h>
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| 16 | #include <linux/string.h>
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| 17 | #include "internal.h"
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| 18 |
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| 19 | static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
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| 20 | unsigned int keylen)
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| 21 | {
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| 22 | struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
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| 23 | unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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| 24 | int ret;
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| 25 | u8 *buffer, *alignbuffer;
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| 26 | unsigned long absize;
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| 27 |
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| 28 | absize = keylen + alignmask;
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| 29 | buffer = kmalloc(absize, GFP_ATOMIC);
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| 30 | if (!buffer)
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| 31 | return -ENOMEM;
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| 32 |
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| 33 | alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
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| 34 | memcpy(alignbuffer, key, keylen);
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| 35 | ret = cia->cia_setkey(tfm, alignbuffer, keylen);
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| 36 | memset(alignbuffer, 0, keylen);
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| 37 | kfree(buffer);
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| 38 | return ret;
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| 39 |
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| 40 | }
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| 41 |
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| 42 | static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
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| 43 | {
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| 44 | struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
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| 45 | unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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| 46 |
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| 47 | tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
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| 48 | if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
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| 49 | tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
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| 50 | return -EINVAL;
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| 51 | }
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| 52 |
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| 53 | if ((unsigned long)key & alignmask)
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| 54 | return setkey_unaligned(tfm, key, keylen);
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| 55 |
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| 56 | return cia->cia_setkey(tfm, key, keylen);
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| 57 | }
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| 58 |
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| 59 | static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
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| 60 | const u8 *),
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| 61 | struct crypto_tfm *tfm,
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| 62 | u8 *dst, const u8 *src)
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| 63 | {
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| 64 | unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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| 65 | unsigned int size = crypto_tfm_alg_blocksize(tfm);
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| 66 | u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
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| 67 | u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
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| 68 |
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| 69 | memcpy(tmp, src, size);
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| 70 | fn(tfm, tmp, tmp);
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| 71 | memcpy(dst, tmp, size);
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| 72 | }
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| 73 |
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| 74 | static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
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| 75 | u8 *dst, const u8 *src)
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| 76 | {
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| 77 | unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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| 78 | struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
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| 79 |
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| 80 | if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
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| 81 | cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
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| 82 | return;
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| 83 | }
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| 84 |
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| 85 | cipher->cia_encrypt(tfm, dst, src);
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| 86 | }
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| 87 |
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| 88 | static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
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| 89 | u8 *dst, const u8 *src)
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| 90 | {
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| 91 | unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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| 92 | struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
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| 93 |
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| 94 | if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
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| 95 | cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
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| 96 | return;
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| 97 | }
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| 98 |
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| 99 | cipher->cia_decrypt(tfm, dst, src);
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| 100 | }
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| 101 |
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| 102 | int crypto_init_cipher_ops(struct crypto_tfm *tfm)
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| 103 | {
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| 104 | struct cipher_tfm *ops = &tfm->crt_cipher;
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| 105 | struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
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| 106 |
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| 107 | ops->cit_setkey = setkey;
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| 108 | ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
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| 109 | cipher_encrypt_unaligned : cipher->cia_encrypt;
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| 110 | ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
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| 111 | cipher_decrypt_unaligned : cipher->cia_decrypt;
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| 112 |
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| 113 | return 0;
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| 114 | }
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