99 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			99 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0-or-later */
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| /*
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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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| #ifndef _CRYPTO_DH_
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| #define _CRYPTO_DH_
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| 
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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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| /**
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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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| 	const void *key;
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| 	const void *p;
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| 	const 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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| /**
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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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| unsigned int crypto_dh_key_len(const struct dh *params);
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| 
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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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| /**
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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:	Length 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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|  *		unpacked 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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| 
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| /**
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|  * __crypto_dh_decode_key() - decode a private key without parameter checks
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|  * @buf:	Buffer holding a packet key that should be decoded
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|  * @len:	Length 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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|  *		unpacked DH private key.
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|  *
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|  * Internal function providing the same services as the exported
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|  * crypto_dh_decode_key(), but without any of those basic parameter
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|  * checks conducted by the latter.
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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,
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| 			   struct dh *params);
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| 
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| #endif
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