1=pod 2 3=head1 NAME 4 5MDC2, MDC2_Init, MDC2_Update, MDC2_Final - MDC2 hash function 6 7=head1 SYNOPSIS 8 9 #include <openssl/mdc2.h> 10 11 unsigned char *MDC2(const unsigned char *d, unsigned long n, 12 unsigned char *md); 13 14 int MDC2_Init(MDC2_CTX *c); 15 int MDC2_Update(MDC2_CTX *c, const unsigned char *data, 16 unsigned long len); 17 int MDC2_Final(unsigned char *md, MDC2_CTX *c); 18 19=head1 DESCRIPTION 20 21MDC2 is a method to construct hash functions with 128 bit output from 22block ciphers. These functions are an implementation of MDC2 with 23DES. 24 25MDC2() computes the MDC2 message digest of the B<n> 26bytes at B<d> and places it in B<md> (which must have space for 27MDC2_DIGEST_LENGTH == 16 bytes of output). If B<md> is NULL, the digest 28is placed in a static array. 29 30The following functions may be used if the message is not completely 31stored in memory: 32 33MDC2_Init() initializes a B<MDC2_CTX> structure. 34 35MDC2_Update() can be called repeatedly with chunks of the message to 36be hashed (B<len> bytes at B<data>). 37 38MDC2_Final() places the message digest in B<md>, which must have space 39for MDC2_DIGEST_LENGTH == 16 bytes of output, and erases the B<MDC2_CTX>. 40 41Applications should use the higher level functions 42L<EVP_DigestInit(3)> etc. instead of calling the 43hash functions directly. 44 45=head1 RETURN VALUES 46 47MDC2() returns a pointer to the hash value. 48 49MDC2_Init(), MDC2_Update() and MDC2_Final() return 1 for success, 0 otherwise. 50 51=head1 CONFORMING TO 52 53ISO/IEC 10118-2:2000 Hash-Function 2, with DES as the underlying block cipher. 54 55=head1 SEE ALSO 56 57L<EVP_DigestInit(3)> 58 59=head1 COPYRIGHT 60 61Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved. 62 63Licensed under the OpenSSL license (the "License"). You may not use 64this file except in compliance with the License. You can obtain a copy 65in the file LICENSE in the source distribution or at 66L<https://www.openssl.org/source/license.html>. 67 68=cut 69