| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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| 2 | |
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| 3 | /* |
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| 4 | * Copyright (C) 2021, Stephan Mueller <smueller@chronox.de> |
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| 5 | */ |
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| 6 | |
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| 7 | #ifndef _CRYPTO_KDF108_H |
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| 8 | #define _CRYPTO_KDF108_H |
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| 9 | |
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| 10 | #include <crypto/hash.h> |
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| 11 | #include <linux/uio.h> |
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| 12 | |
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| 13 | /** |
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| 14 | * Counter KDF generate operation according to SP800-108 section 5.1 |
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| 15 | * as well as SP800-56A section 5.8.1 (Single-step KDF). |
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| 16 | * |
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| 17 | * @kmd Keyed message digest whose key was set with crypto_kdf108_setkey or |
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| 18 | * unkeyed message digest |
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| 19 | * @info optional context and application specific information - this may be |
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| 20 | * NULL |
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| 21 | * @info_vec number of optional context/application specific information entries |
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| 22 | * @dst destination buffer that the caller already allocated |
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| 23 | * @dlen length of the destination buffer - the KDF derives that amount of |
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| 24 | * bytes. |
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| 25 | * |
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| 26 | * To comply with SP800-108, the caller must provide Label || 0x00 || Context |
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| 27 | * in the info parameter. |
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| 28 | * |
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| 29 | * @return 0 on success, < 0 on error |
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| 30 | */ |
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| 31 | int crypto_kdf108_ctr_generate(struct crypto_shash *kmd, |
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| 32 | const struct kvec *info, unsigned int info_nvec, |
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| 33 | u8 *dst, unsigned int dlen); |
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| 34 | |
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| 35 | /** |
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| 36 | * Counter KDF setkey operation |
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| 37 | * |
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| 38 | * @kmd Keyed message digest allocated by the caller. The key should not have |
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| 39 | * been set. |
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| 40 | * @key Seed key to be used to initialize the keyed message digest context. |
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| 41 | * @keylen This length of the key buffer. |
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| 42 | * @ikm The SP800-108 KDF does not support IKM - this parameter must be NULL |
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| 43 | * @ikmlen This parameter must be 0. |
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| 44 | * |
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| 45 | * According to SP800-108 section 7.2, the seed key must be at least as large as |
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| 46 | * the message digest size of the used keyed message digest. This limitation |
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| 47 | * is enforced by the implementation. |
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| 48 | * |
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| 49 | * SP800-108 allows the use of either a HMAC or a hash primitive. When |
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| 50 | * the caller intends to use a hash primitive, the call to |
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| 51 | * crypto_kdf108_setkey is not required and the key derivation operation can |
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| 52 | * immediately performed using crypto_kdf108_ctr_generate after allocating |
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| 53 | * a handle. |
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| 54 | * |
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| 55 | * @return 0 on success, < 0 on error |
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| 56 | */ |
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| 57 | int crypto_kdf108_setkey(struct crypto_shash *kmd, |
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| 58 | const u8 *key, size_t keylen, |
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| 59 | const u8 *ikm, size_t ikmlen); |
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| 60 | |
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| 61 | #endif /* _CRYPTO_KDF108_H */ |
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| 62 | |
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