59 lines
1.3 KiB
C
59 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _CRYPTO_XTS_H
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#define _CRYPTO_XTS_H
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#include <crypto/b128ops.h>
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#include <crypto/internal/skcipher.h>
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#include <linux/fips.h>
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#define XTS_BLOCK_SIZE 16
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static inline int xts_check_key(struct crypto_tfm *tfm,
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const u8 *key, unsigned int keylen)
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{
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u32 *flags = &tfm->crt_flags;
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/*
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* key consists of keys of equal size concatenated, therefore
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* the length must be even.
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*/
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if (keylen % 2) {
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*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
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return -EINVAL;
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}
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/* ensure that the AES and tweak key are not identical */
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if (fips_enabled &&
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!crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
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*flags |= CRYPTO_TFM_RES_WEAK_KEY;
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return -EINVAL;
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}
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return 0;
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}
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static inline int xts_verify_key(struct crypto_skcipher *tfm,
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const u8 *key, unsigned int keylen)
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{
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/*
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* key consists of keys of equal size concatenated, therefore
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* the length must be even.
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*/
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if (keylen % 2) {
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crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
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return -EINVAL;
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}
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/* ensure that the AES and tweak key are not identical */
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if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
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CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
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!crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
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crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_WEAK_KEY);
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return -EINVAL;
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}
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return 0;
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}
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#endif /* _CRYPTO_XTS_H */
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