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1/* SPDX-License-Identifier: GPL-2.0 */2 3/*4 * Copyright (C) 2021, Stephan Mueller <smueller@chronox.de>5 */6 7#ifndef _CRYPTO_KDF108_H8#define _CRYPTO_KDF108_H9 10#include <crypto/hash.h>11#include <linux/uio.h>12 13/**14 * Counter KDF generate operation according to SP800-108 section 5.115 * as well as SP800-56A section 5.8.1 (Single-step KDF).16 *17 * @kmd Keyed message digest whose key was set with crypto_kdf108_setkey or18 * unkeyed message digest19 * @info optional context and application specific information - this may be20 * NULL21 * @info_vec number of optional context/application specific information entries22 * @dst destination buffer that the caller already allocated23 * @dlen length of the destination buffer - the KDF derives that amount of24 * bytes.25 *26 * To comply with SP800-108, the caller must provide Label || 0x00 || Context27 * in the info parameter.28 *29 * @return 0 on success, < 0 on error30 */31int crypto_kdf108_ctr_generate(struct crypto_shash *kmd,32 const struct kvec *info, unsigned int info_nvec,33 u8 *dst, unsigned int dlen);34 35/**36 * Counter KDF setkey operation37 *38 * @kmd Keyed message digest allocated by the caller. The key should not have39 * been set.40 * @key Seed key to be used to initialize the keyed message digest context.41 * @keylen This length of the key buffer.42 * @ikm The SP800-108 KDF does not support IKM - this parameter must be NULL43 * @ikmlen This parameter must be 0.44 *45 * According to SP800-108 section 7.2, the seed key must be at least as large as46 * the message digest size of the used keyed message digest. This limitation47 * is enforced by the implementation.48 *49 * SP800-108 allows the use of either a HMAC or a hash primitive. When50 * the caller intends to use a hash primitive, the call to51 * crypto_kdf108_setkey is not required and the key derivation operation can52 * immediately performed using crypto_kdf108_ctr_generate after allocating53 * a handle.54 *55 * @return 0 on success, < 0 on error56 */57int crypto_kdf108_setkey(struct crypto_shash *kmd,58 const u8 *key, size_t keylen,59 const u8 *ikm, size_t ikmlen);60 61#endif /* _CRYPTO_KDF108_H */62