NetBSD/lib/libcrypto/man/MD5_Init.3

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.rm #[ #] #H #V #F C
.SH "NAME"
MD2, MD5, MD2_Init, MD2_Update, MD2_Final, MD5_Init, MD5_Update,
MD5_Final \- MD2 and MD5 hash functions
.SH "LIBRARY"
libcrypto, -lcrypto
.SH "SYNOPSIS"
.PP
.Vb 1
\& #include <openssl/md2.h>
.Ve
.Vb 2
\& unsigned char *MD2(const unsigned char *d, unsigned long n,
\&                  unsigned char *md);
.Ve
.Vb 4
\& void MD2_Init(MD2_CTX *c);
\& void MD2_Update(MD2_CTX *c, const unsigned char *data,
\&                  unsigned long len);
\& void MD2_Final(unsigned char *md, MD2_CTX *c);
.Ve
.Vb 1
\& #include <openssl/md5.h>
.Ve
.Vb 2
\& unsigned char *MD5(const unsigned char *d, unsigned long n,
\&                  unsigned char *md);
.Ve
.Vb 4
\& void MD5_Init(MD5_CTX *c);
\& void MD5_Update(MD5_CTX *c, const void *data,
\&                  unsigned long len);
\& void MD5_Final(unsigned char *md, MD5_CTX *c);
.Ve
.SH "DESCRIPTION"
MD2 and MD5 are cryptographic hash functions with a 128 bit output.
.PP
\fIMD2()\fR and \fIMD5()\fR compute the MD2 and MD5 message digest of the \fBn\fR
bytes at \fBd\fR and place it in \fBmd\fR (which must have space for
MD2_DIGEST_LENGTH == MD5_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
\fIMD2_Init()\fR initializes a \fBMD2_CTX\fR structure.
.PP
\fIMD2_Update()\fR can be called repeatedly with chunks of the message to
be hashed (\fBlen\fR bytes at \fBdata\fR).
.PP
\fIMD2_Final()\fR places the message digest in \fBmd\fR, which must have space
for MD2_DIGEST_LENGTH == 16 bytes of output, and erases the \fBMD2_CTX\fR.
.PP
\fIMD5_Init()\fR, \fIMD5_Update()\fR and \fIMD5_Final()\fR are analogous using an
\fBMD5_CTX\fR structure.
.PP
Applications should use the higher level functions
the \fIEVP_DigestInit(3)|EVP_DigestInit(3)\fR manpage
etc. instead of calling the hash functions directly.
.SH "NOTE"
MD2 and MD5 are recommended only for compatibility with existing
applications. In new applications, SHA\-1 or RIPEMD\-160 should be
preferred.
.SH "RETURN VALUES"
\fIMD2()\fR and \fIMD5()\fR return pointers to the hash value. 
.PP
\fIMD2_Init()\fR, \fIMD2_Update()\fR \fIMD2_Final()\fR, \fIMD5_Init()\fR, \fIMD5_Update()\fR and
\fIMD5_Final()\fR do not return values.
.SH "CONFORMING TO"
RFC 1319, RFC 1321
.SH "SEE ALSO"
the \fIsha(3)|sha(3)\fR manpage, the \fIripemd(3)|ripemd(3)\fR manpage, the \fIEVP_DigestInit(3)|EVP_DigestInit(3)\fR manpage
.SH "HISTORY"
\fIMD2()\fR, \fIMD2_Init()\fR, \fIMD2_Update()\fR \fIMD2_Final()\fR, \fIMD5()\fR, \fIMD5_Init()\fR,
\fIMD5_Update()\fR and \fIMD5_Final()\fR are available in all versions of SSLeay
and OpenSSL.

.rn }` ''
.IX Title "md5 3"
.IX Name "MD2, MD5, MD2_Init, MD2_Update, MD2_Final, MD5_Init, MD5_Update,
MD5_Final - MD2 and MD5 hash functions"

.IX Header "NAME"

.IX Header "SYNOPSIS"

.IX Header "DESCRIPTION"

.IX Header "NOTE"

.IX Header "RETURN VALUES"

.IX Header "CONFORMING TO"

.IX Header "SEE ALSO"

.IX Header "HISTORY"