.\" $OpenBSD: MD5.3,v 1.4 2016/11/27 16:20:15 schwarze Exp $ .\" OpenSSL 99d63d46 Oct 26 13:56:48 2016 -0400 .\" .\" This file was written by Ulf Moeller and .\" Richard Levitte . .\" Copyright (c) 2000, 2006 The OpenSSL Project. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in .\" the documentation and/or other materials provided with the .\" distribution. .\" .\" 3. All advertising materials mentioning features or use of this .\" software must display the following acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" .\" .\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to .\" endorse or promote products derived from this software without .\" prior written permission. For written permission, please contact .\" openssl-core@openssl.org. .\" .\" 5. Products derived from this software may not be called "OpenSSL" .\" nor may "OpenSSL" appear in their names without prior written .\" permission of the OpenSSL Project. .\" .\" 6. Redistributions of any form whatsoever must retain the following .\" acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" .\" .\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY .\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: November 27 2016 $ .Dt MD5 3 .Os .Sh NAME .Nm MD2 , .Nm MD4 , .Nm MD5 , .Nm MD2_Init , .Nm MD2_Update , .Nm MD2_Final , .Nm MD4_Init , .Nm MD4_Update , .Nm MD4_Final , .Nm MD5_Init , .Nm MD5_Update , .Nm MD5_Final .Nd MD2, MD4, and MD5 hash functions .Sh SYNOPSIS .In openssl/md2.h .Ft unsigned char * .Fo MD2 .Fa "const unsigned char *d" .Fa "unsigned long n" .Fa "unsigned char *md" .Fc .Ft int .Fo MD2_Init .Fa "MD2_CTX *c" .Fc .Ft int .Fo MD2_Update .Fa "MD2_CTX *c" .Fa "const unsigned char *data" .Fa "unsigned long len" .Fc .Ft int .Fo MD2_Final .Fa "unsigned char *md" .Fa "MD2_CTX *c" .Fc .In openssl/md4.h .Ft unsigned char * .Fo MD4 .Fa "const unsigned char *d" .Fa "unsigned long n" .Fa "unsigned char *md" .Fc .Ft int .Fo MD4_Init .Fa "MD4_CTX *c" .Fc .Ft int .Fo MD4_Update .Fa "MD4_CTX *c" .Fa "const void *data" .Fa "unsigned long len" .Fc .Ft int .Fo MD4_Final .Fa "unsigned char *md" .Fa "MD4_CTX *c" .Fc .In openssl/md5.h .Ft unsigned char * .Fo MD5 .Fa "const unsigned char *d" .Fa "unsigned long n" .Fa "unsigned char *md" .Fc .Ft int .Fo MD5_Init .Fa "MD5_CTX *c" .Fc .Ft int .Fo MD5_Update .Fa "MD5_CTX *c" .Fa "const void *data" .Fa "unsigned long len" .Fc .Ft int .Fo MD5_Final .Fa "unsigned char *md" .Fa "MD5_CTX *c" .Fc .Sh DESCRIPTION MD2, MD4, and MD5 are cryptographic hash functions with a 128-bit output. .Pp .Fn MD2 , .Fn MD4 , and .Fn MD5 compute the MD2, MD4, and MD5 message digest of the .Fa n bytes at .Fa d and place it in .Fa md , which must have space for .Dv MD2_DIGEST_LENGTH No == .Dv MD4_DIGEST_LENGTH No == .Dv MD5_DIGEST_LENGTH No == 16 bytes of output. If .Fa md is .Dv NULL , the digest is placed in a static array. .Pp The following functions may be used if the message is not completely stored in memory: .Pp .Fn MD2_Init initializes a .Vt MD2_CTX structure. .Pp .Fn MD2_Update can be called repeatedly with chunks of the message to be hashed .Pq Fa len No bytes at Fa data . .Pp .Fn MD2_Final places the message digest in .Fa md , which must have space for .Dv MD2_DIGEST_LENGTH No == 16 bytes of output, and erases the .Vt MD2_CTX . .Pp .Fn MD4_Init , .Fn MD4_Update , .Fn MD4_Final , .Fn MD5_Init , .Fn MD5_Update , and .Fn MD5_Final are analogous using an .Vt MD4_CTX and .Vt MD5_CTX structure. .Pp Applications should use the higher level functions .Xr EVP_DigestInit 3 etc. instead of calling these hash functions directly. .Sh RETURN VALUES .Fn MD2 , .Fn MD4 , and .Fn MD5 return pointers to the hash value. .Pp .Fn MD2_Init , .Fn MD2_Update , .Fn MD2_Final , .Fn MD4_Init , .Fn MD4_Update , .Fn MD4_Final , .Fn MD5_Init , .Fn MD5_Update , and .Fn MD5_Final return 1 for success or 0 otherwise. .Sh SEE ALSO .Xr EVP_DigestInit 3 .Sh STANDARDS RFC 1319, RFC 1320, RFC 1321 .Sh HISTORY .Fn MD2 , .Fn MD2_Init , .Fn MD2_Update , .Fn MD2_Final , .Fn MD5 , .Fn MD5_Init , .Fn MD5_Update , and .Fn MD5_Final are available in all versions of SSLeay and OpenSSL. .Pp .Fn MD4 , .Fn MD4_Init , and .Fn MD4_Update are available in OpenSSL 0.9.6 and above.