8d23da22ac
Add the KPP API documentation to the kernel crypto API Sphinx documentation. This addition includes the documentation of the ECDH and DH helpers which are needed to create the approrpiate input data for the crypto_kpp_set_secret function. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
88 lines
2.6 KiB
C
88 lines
2.6 KiB
C
/*
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* Diffie-Hellman secret to be used with kpp API along with helper functions
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*
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* Copyright (c) 2016, Intel Corporation
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* Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#ifndef _CRYPTO_DH_
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#define _CRYPTO_DH_
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/**
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* DOC: DH Helper Functions
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*
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* To use DH with the KPP cipher API, the following data structure and
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* functions should be used.
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*
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* To use DH with KPP, the following functions should be used to operate on
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* a DH private key. The packet private key that can be set with
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* the KPP API function call of crypto_kpp_set_secret.
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*/
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/**
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* struct dh - define a DH private key
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*
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* @key: Private DH key
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* @p: Diffie-Hellman parameter P
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* @g: Diffie-Hellman generator G
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* @key_size: Size of the private DH key
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* @p_size: Size of DH parameter P
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* @g_size: Size of DH generator G
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*/
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struct dh {
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void *key;
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void *p;
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void *g;
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unsigned int key_size;
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unsigned int p_size;
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unsigned int g_size;
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};
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/**
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* crypto_dh_key_len() - Obtain the size of the private DH key
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* @params: private DH key
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*
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* This function returns the packet DH key size. A caller can use that
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* with the provided DH private key reference to obtain the required
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* memory size to hold a packet key.
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*
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* Return: size of the key in bytes
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*/
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int crypto_dh_key_len(const struct dh *params);
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/**
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* crypto_dh_encode_key() - encode the private key
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* @buf: Buffer allocated by the caller to hold the packet DH
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* private key. The buffer should be at least crypto_dh_key_len
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* bytes in size.
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* @len: Length of the packet private key buffer
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* @params: Buffer with the caller-specified private key
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*
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* The DH implementations operate on a packet representation of the private
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* key.
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*
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* Return: -EINVAL if buffer has insufficient size, 0 on success
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*/
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int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params);
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/**
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* crypto_dh_decode_key() - decode a private key
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* @buf: Buffer holding a packet key that should be decoded
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* @len: Lenth of the packet private key buffer
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* @params: Buffer allocated by the caller that is filled with the
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* unpacket DH private key.
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*
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* The unpacking obtains the private key by pointing @p to the correct location
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* in @buf. Thus, both pointers refer to the same memory.
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*
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* Return: -EINVAL if buffer has insufficient size, 0 on success
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*/
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int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params);
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#endif
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