1*4724848cSchristos=pod 2*4724848cSchristos 3*4724848cSchristos=head1 NAME 4*4724848cSchristos 5*4724848cSchristosMDC2, MDC2_Init, MDC2_Update, MDC2_Final - MDC2 hash function 6*4724848cSchristos 7*4724848cSchristos=head1 SYNOPSIS 8*4724848cSchristos 9*4724848cSchristos #include <openssl/mdc2.h> 10*4724848cSchristos 11*4724848cSchristos unsigned char *MDC2(const unsigned char *d, unsigned long n, 12*4724848cSchristos unsigned char *md); 13*4724848cSchristos 14*4724848cSchristos int MDC2_Init(MDC2_CTX *c); 15*4724848cSchristos int MDC2_Update(MDC2_CTX *c, const unsigned char *data, 16*4724848cSchristos unsigned long len); 17*4724848cSchristos int MDC2_Final(unsigned char *md, MDC2_CTX *c); 18*4724848cSchristos 19*4724848cSchristos=head1 DESCRIPTION 20*4724848cSchristos 21*4724848cSchristosMDC2 is a method to construct hash functions with 128 bit output from 22*4724848cSchristosblock ciphers. These functions are an implementation of MDC2 with 23*4724848cSchristosDES. 24*4724848cSchristos 25*4724848cSchristosMDC2() computes the MDC2 message digest of the B<n> 26*4724848cSchristosbytes at B<d> and places it in B<md> (which must have space for 27*4724848cSchristosMDC2_DIGEST_LENGTH == 16 bytes of output). If B<md> is NULL, the digest 28*4724848cSchristosis placed in a static array. 29*4724848cSchristos 30*4724848cSchristosThe following functions may be used if the message is not completely 31*4724848cSchristosstored in memory: 32*4724848cSchristos 33*4724848cSchristosMDC2_Init() initializes a B<MDC2_CTX> structure. 34*4724848cSchristos 35*4724848cSchristosMDC2_Update() can be called repeatedly with chunks of the message to 36*4724848cSchristosbe hashed (B<len> bytes at B<data>). 37*4724848cSchristos 38*4724848cSchristosMDC2_Final() places the message digest in B<md>, which must have space 39*4724848cSchristosfor MDC2_DIGEST_LENGTH == 16 bytes of output, and erases the B<MDC2_CTX>. 40*4724848cSchristos 41*4724848cSchristosApplications should use the higher level functions 42*4724848cSchristosL<EVP_DigestInit(3)> etc. instead of calling the 43*4724848cSchristoshash functions directly. 44*4724848cSchristos 45*4724848cSchristos=head1 RETURN VALUES 46*4724848cSchristos 47*4724848cSchristosMDC2() returns a pointer to the hash value. 48*4724848cSchristos 49*4724848cSchristosMDC2_Init(), MDC2_Update() and MDC2_Final() return 1 for success, 0 otherwise. 50*4724848cSchristos 51*4724848cSchristos=head1 CONFORMING TO 52*4724848cSchristos 53*4724848cSchristosISO/IEC 10118-2:2000 Hash-Function 2, with DES as the underlying block cipher. 54*4724848cSchristos 55*4724848cSchristos=head1 SEE ALSO 56*4724848cSchristos 57*4724848cSchristosL<EVP_DigestInit(3)> 58*4724848cSchristos 59*4724848cSchristos=head1 COPYRIGHT 60*4724848cSchristos 61*4724848cSchristosCopyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved. 62*4724848cSchristos 63*4724848cSchristosLicensed under the OpenSSL license (the "License"). You may not use 64*4724848cSchristosthis file except in compliance with the License. You can obtain a copy 65*4724848cSchristosin the file LICENSE in the source distribution or at 66*4724848cSchristosL<https://www.openssl.org/source/license.html>. 67*4724848cSchristos 68*4724848cSchristos=cut 69