This patch adds the possibility to calculate the DES-CBC-MAC of a source buffer (i.e. the last block of the buffer encrypted in CBC mode) without having to allocate a destination buffer that is as long as the complete source buffer, but instead only 8 bytes for the MAC. Signed-off-by: David Goldwich <david.goldwich@gmail.com> Signed-off-by: Anton Khirnov <anton@khirnov.net>
		
			
				
	
	
		
			62 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			62 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * DES encryption/decryption
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 * Copyright (c) 2007 Reimar Doeffinger
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef AVUTIL_DES_H
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#define AVUTIL_DES_H
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#include <stdint.h>
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struct AVDES {
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    uint64_t round_keys[3][16];
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    int triple_des;
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};
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/**
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 * @brief Initializes an AVDES context.
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 *
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 * @param key_bits must be 64 or 192
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 * @param decrypt 0 for encryption/CBC-MAC, 1 for decryption
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 */
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int av_des_init(struct AVDES *d, const uint8_t *key, int key_bits, int decrypt);
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/**
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 * @brief Encrypts / decrypts using the DES algorithm.
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 *
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 * @param count number of 8 byte blocks
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 * @param dst destination array, can be equal to src, must be 8-byte aligned
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 * @param src source array, can be equal to dst, must be 8-byte aligned, may be NULL
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 * @param iv initialization vector for CBC mode, if NULL then ECB will be used,
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 *           must be 8-byte aligned
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 * @param decrypt 0 for encryption, 1 for decryption
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 */
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void av_des_crypt(struct AVDES *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt);
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/**
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 * @brief Calculates CBC-MAC using the DES algorithm.
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 *
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 * @param count number of 8 byte blocks
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 * @param dst destination array, can be equal to src, must be 8-byte aligned
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 * @param src source array, can be equal to dst, must be 8-byte aligned, may be NULL
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 */
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void av_des_mac(struct AVDES *d, uint8_t *dst, const uint8_t *src, int count);
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#endif /* AVUTIL_DES_H */
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