1=pod 2 3=head1 NAME 4 5MD2, MD4, MD5, MD2_Init, MD2_Update, MD2_Final, MD4_Init, MD4_Update, 6MD4_Final, MD5_Init, MD5_Update, MD5_Final - MD2, MD4, and MD5 hash functions 7 8=head1 SYNOPSIS 9 10 #include <openssl/md2.h> 11 12The following functions have been deprecated since OpenSSL 3.0, and can be 13hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 14see L<openssl_user_macros(7)>: 15 16 unsigned char *MD2(const unsigned char *d, unsigned long n, unsigned char *md); 17 18 int MD2_Init(MD2_CTX *c); 19 int MD2_Update(MD2_CTX *c, const unsigned char *data, unsigned long len); 20 int MD2_Final(unsigned char *md, MD2_CTX *c); 21 22 23 #include <openssl/md4.h> 24 25The following functions have been deprecated since OpenSSL 3.0, and can be 26hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 27see L<openssl_user_macros(7)>: 28 29 unsigned char *MD4(const unsigned char *d, unsigned long n, unsigned char *md); 30 31 int MD4_Init(MD4_CTX *c); 32 int MD4_Update(MD4_CTX *c, const void *data, unsigned long len); 33 int MD4_Final(unsigned char *md, MD4_CTX *c); 34 35 36 #include <openssl/md5.h> 37 38The following functions have been deprecated since OpenSSL 3.0, and can be 39hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 40see L<openssl_user_macros(7)>: 41 42 unsigned char *MD5(const unsigned char *d, unsigned long n, unsigned char *md); 43 44 int MD5_Init(MD5_CTX *c); 45 int MD5_Update(MD5_CTX *c, const void *data, unsigned long len); 46 int MD5_Final(unsigned char *md, MD5_CTX *c); 47 48=head1 DESCRIPTION 49 50All of the functions described on this page are deprecated. 51Applications should instead use L<EVP_DigestInit_ex(3)>, L<EVP_DigestUpdate(3)> 52and L<EVP_DigestFinal_ex(3)>. 53 54MD2, MD4, and MD5 are cryptographic hash functions with a 128 bit output. 55 56MD2(), MD4(), and MD5() compute the MD2, MD4, and MD5 message digest 57of the B<n> bytes at B<d> and place it in B<md> (which must have space 58for MD2_DIGEST_LENGTH == MD4_DIGEST_LENGTH == MD5_DIGEST_LENGTH == 16 59bytes of output). If B<md> is NULL, the digest is placed in a static 60array. 61 62The following functions may be used if the message is not completely 63stored in memory: 64 65MD2_Init() initializes a B<MD2_CTX> structure. 66 67MD2_Update() can be called repeatedly with chunks of the message to 68be hashed (B<len> bytes at B<data>). 69 70MD2_Final() places the message digest in B<md>, which must have space 71for MD2_DIGEST_LENGTH == 16 bytes of output, and erases the B<MD2_CTX>. 72 73MD4_Init(), MD4_Update(), MD4_Final(), MD5_Init(), MD5_Update(), and 74MD5_Final() are analogous using an B<MD4_CTX> and B<MD5_CTX> structure. 75 76Applications should use the higher level functions 77L<EVP_DigestInit(3)> 78etc. instead of calling the hash functions directly. 79 80=head1 NOTE 81 82MD2, MD4, and MD5 are recommended only for compatibility with existing 83applications. In new applications, hashes from the SHA-2 or SHA-3 family 84should be preferred. 85 86=head1 RETURN VALUES 87 88MD2(), MD4(), and MD5() return pointers to the hash value. 89 90MD2_Init(), MD2_Update(), MD2_Final(), MD4_Init(), MD4_Update(), 91MD4_Final(), MD5_Init(), MD5_Update(), and MD5_Final() return 1 for 92success, 0 otherwise. 93 94=head1 CONFORMING TO 95 96RFC 1319, RFC 1320, RFC 1321 97 98=head1 SEE ALSO 99 100L<EVP_DigestInit(3)>, L<EVP_MD-SHA2(7)>, L<EVP_MD-SHA3(7)> 101 102=head1 HISTORY 103 104All of these functions were deprecated in OpenSSL 3.0. 105 106=head1 COPYRIGHT 107 108Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved. 109 110Licensed under the Apache License 2.0 (the "License"). You may not use 111this file except in compliance with the License. You can obtain a copy 112in the file LICENSE in the source distribution or at 113L<https://www.openssl.org/source/license.html>. 114 115=cut 116