| yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame^] | 1 | =pod |
| 2 | |
| 3 | =head1 NAME |
| 4 | |
| 5 | MDC2, 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 | |
| 21 | MDC2 is a method to construct hash functions with 128 bit output from |
| 22 | block ciphers. These functions are an implementation of MDC2 with |
| 23 | DES. |
| 24 | |
| 25 | MDC2() computes the MDC2 message digest of the B<n> |
| 26 | bytes at B<d> and places it in B<md> (which must have space for |
| 27 | MDC2_DIGEST_LENGTH == 16 bytes of output). If B<md> is NULL, the digest |
| 28 | is placed in a static array. |
| 29 | |
| 30 | The following functions may be used if the message is not completely |
| 31 | stored in memory: |
| 32 | |
| 33 | MDC2_Init() initializes a B<MDC2_CTX> structure. |
| 34 | |
| 35 | MDC2_Update() can be called repeatedly with chunks of the message to |
| 36 | be hashed (B<len> bytes at B<data>). |
| 37 | |
| 38 | MDC2_Final() places the message digest in B<md>, which must have space |
| 39 | for MDC2_DIGEST_LENGTH == 16 bytes of output, and erases the B<MDC2_CTX>. |
| 40 | |
| 41 | Applications should use the higher level functions |
| 42 | L<EVP_DigestInit(3)> etc. instead of calling the |
| 43 | hash functions directly. |
| 44 | |
| 45 | =head1 RETURN VALUES |
| 46 | |
| 47 | MDC2() returns a pointer to the hash value. |
| 48 | |
| 49 | MDC2_Init(), MDC2_Update() and MDC2_Final() return 1 for success, 0 otherwise. |
| 50 | |
| 51 | =head1 CONFORMING TO |
| 52 | |
| 53 | ISO/IEC 10118-2:2000 Hash-Function 2, with DES as the underlying block cipher. |
| 54 | |
| 55 | =head1 SEE ALSO |
| 56 | |
| 57 | L<EVP_DigestInit(3)> |
| 58 | |
| 59 | =head1 COPYRIGHT |
| 60 | |
| 61 | Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved. |
| 62 | |
| 63 | Licensed under the OpenSSL license (the "License"). You may not use |
| 64 | this file except in compliance with the License. You can obtain a copy |
| 65 | in the file LICENSE in the source distribution or at |
| 66 | L<https://www.openssl.org/source/license.html>. |
| 67 | |
| 68 | =cut |