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 12 unsigned char *MD2(const unsigned char *d, unsigned long n, 13 unsigned char *md); 14 15 int MD2_Init(MD2_CTX *c); 16 int MD2_Update(MD2_CTX *c, const unsigned char *data, 17 unsigned long len); 18 int MD2_Final(unsigned char *md, MD2_CTX *c); 19 20 21 #include <openssl/md4.h> 22 23 unsigned char *MD4(const unsigned char *d, unsigned long n, 24 unsigned char *md); 25 26 int MD4_Init(MD4_CTX *c); 27 int MD4_Update(MD4_CTX *c, const void *data, 28 unsigned long len); 29 int MD4_Final(unsigned char *md, MD4_CTX *c); 30 31 32 #include <openssl/md5.h> 33 34 unsigned char *MD5(const unsigned char *d, unsigned long n, 35 unsigned char *md); 36 37 int MD5_Init(MD5_CTX *c); 38 int MD5_Update(MD5_CTX *c, const void *data, 39 unsigned long len); 40 int MD5_Final(unsigned char *md, MD5_CTX *c); 41 42=head1 DESCRIPTION 43 44MD2, MD4, and MD5 are cryptographic hash functions with a 128 bit output. 45 46MD2(), MD4(), and MD5() compute the MD2, MD4, and MD5 message digest 47of the B<n> bytes at B<d> and place it in B<md> (which must have space 48for MD2_DIGEST_LENGTH == MD4_DIGEST_LENGTH == MD5_DIGEST_LENGTH == 16 49bytes of output). If B<md> is NULL, the digest is placed in a static 50array. 51 52The following functions may be used if the message is not completely 53stored in memory: 54 55MD2_Init() initializes a B<MD2_CTX> structure. 56 57MD2_Update() can be called repeatedly with chunks of the message to 58be hashed (B<len> bytes at B<data>). 59 60MD2_Final() places the message digest in B<md>, which must have space 61for MD2_DIGEST_LENGTH == 16 bytes of output, and erases the B<MD2_CTX>. 62 63MD4_Init(), MD4_Update(), MD4_Final(), MD5_Init(), MD5_Update(), and 64MD5_Final() are analogous using an B<MD4_CTX> and B<MD5_CTX> structure. 65 66Applications should use the higher level functions 67L<EVP_DigestInit(3)|EVP_DigestInit(3)> 68etc. instead of calling the hash functions directly. 69 70=head1 NOTE 71 72MD2, MD4, and MD5 are recommended only for compatibility with existing 73applications. In new applications, SHA-1 or RIPEMD-160 should be 74preferred. 75 76=head1 RETURN VALUES 77 78MD2(), MD4(), and MD5() return pointers to the hash value. 79 80MD2_Init(), MD2_Update(), MD2_Final(), MD4_Init(), MD4_Update(), 81MD4_Final(), MD5_Init(), MD5_Update(), and MD5_Final() return 1 for 82success, 0 otherwise. 83 84=head1 CONFORMING TO 85 86RFC 1319, RFC 1320, RFC 1321 87 88=head1 SEE ALSO 89 90L<sha(3)|sha(3)>, L<ripemd(3)|ripemd(3)>, L<EVP_DigestInit(3)|EVP_DigestInit(3)> 91 92=head1 HISTORY 93 94MD2(), MD2_Init(), MD2_Update() MD2_Final(), MD5(), MD5_Init(), 95MD5_Update() and MD5_Final() are available in all versions of SSLeay 96and OpenSSL. 97 98MD4(), MD4_Init(), and MD4_Update() are available in OpenSSL 0.9.6 and 99above. 100 101=cut 102