.rn '' }`
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''' $Log$
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'''
'''     Set up \*(-- to give an unbreakable dash;
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.\"	If the F register is turned on, we'll generate
.\"	index entries out stderr for the following things:
.\"		TH	Title 
.\"		SH	Header
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.\"	Of course, you have to process the output yourself
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.rm #[ #] #H #V #F C
.SH "NAME"
MDC2, MDC2_Init, MDC2_Update, MDC2_Final \- MDC2 hash function
.SH "SYNOPSIS"
.PP
.Vb 1
\& #include <openssl/mdc2.h>
.Ve
.Vb 2
\& unsigned char *MDC2(const unsigned char *d, unsigned long n,
\&                  unsigned char *md);
.Ve
.Vb 4
\& void MDC2_Init(MDC2_CTX *c);
\& void MDC2_Update(MDC2_CTX *c, const unsigned char *data,
\&                  unsigned long len);
\& void MDC2_Final(unsigned char *md, MDC2_CTX *c);
.Ve
.SH "DESCRIPTION"
MDC2 is a method to construct hash functions with 128 bit output from
block ciphers.  These functions are an implementation of MDC2 with
DES.
.PP
\fIMDC2()\fR computes the MDC2 message digest of the \fBn\fR
bytes at \fBd\fR and places it in \fBmd\fR (which must have space for
MDC2_DIGEST_LENGTH == 16 bytes of output). If \fBmd\fR is 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
\fIMDC2_Init()\fR initializes a \fBMDC2_CTX\fR structure.
.PP
\fIMDC2_Update()\fR can be called repeatedly with chunks of the message to
be hashed (\fBlen\fR bytes at \fBdata\fR).
.PP
\fIMDC2_Final()\fR places the message digest in \fBmd\fR, which must have space
for MDC2_DIGEST_LENGTH == 16 bytes of output, and erases the \fBMDC2_CTX\fR.
.PP
Applications should use the higher level functions
EVP_DigestInit(3) etc. instead of calling the
hash functions directly.
.SH "RETURN VALUES"
\fIMDC2()\fR returns a pointer to the hash value. 
.PP
\fIMDC2_Init()\fR, \fIMDC2_Update()\fR and \fIMDC2_Final()\fR do not return values.
.SH "CONFORMING TO"
ISO/IEC 10118-2, with DES
.SH "SEE ALSO"
sha(3), EVP_DigestInit(3)
.SH "HISTORY"
\fIMDC2()\fR, \fIMDC2_Init()\fR, \fIMDC2_Update()\fR and \fIMDC2_Final()\fR are available since
SSLeay 0.8.

.rn }` ''
.IX Title "mdc2 3"
.IX Name "MDC2, MDC2_Init, MDC2_Update, MDC2_Final - MDC2 hash function"

.IX Header "NAME"

.IX Header "SYNOPSIS"

.IX Header "DESCRIPTION"

.IX Header "RETURN VALUES"

.IX Header "CONFORMING TO"

.IX Header "SEE ALSO"

.IX Header "HISTORY"