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Revision 1.5, Sat Jul 2 16:04:47 2016 UTC (4 years, 4 months ago) by wiz
Branch: MAIN
CVS Tags: prg-localcount2-base3, prg-localcount2-base2, prg-localcount2-base1, prg-localcount2-base, prg-localcount2, pgoyette-localcount-base, pgoyette-localcount-20170426, pgoyette-localcount-20170320, pgoyette-localcount-20170107, pgoyette-localcount-20161104, pgoyette-localcount-20160806, pgoyette-localcount-20160726, pgoyette-localcount, pgoyette-compat-base, pgoyette-compat-0521, pgoyette-compat-0502, pgoyette-compat-0422, pgoyette-compat-0415, pgoyette-compat-0407, pgoyette-compat-0330, pgoyette-compat-0322, pgoyette-compat-0315, perseant-stdc-iso10646-base, perseant-stdc-iso10646, netbsd-8-base, netbsd-8-2-RELEASE, netbsd-8-1-RELEASE, netbsd-8-1-RC1, netbsd-8-0-RELEASE, netbsd-8-0-RC2, netbsd-8-0-RC1, netbsd-8, matt-nb8-mediatek-base, matt-nb8-mediatek, localcount-20160914, bouyer-socketcan-base1, bouyer-socketcan-base, bouyer-socketcan
Branch point for: pgoyette-compat
Changes since 1.4: +2 -2 lines

Fix pasto.

.\" $NetBSD: hmac.3,v 1.5 2016/07/02 16:04:47 wiz Exp $
.\"
.\" Copyright (c) 2016 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Christos Zoulas.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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.Dd July 1, 2016
.Dt HMAC 3
.Os
.Sh NAME
.Nm hmac
.Nd compute a key-Hash Message Authentication Code
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdlib.h
.Ft ssize_t
.Fn hmac "const char *hname" "const void *key" "size_t klen" "const void *text" "size_t tlen" "void *digest" "size_t dlen"
.Sh DESCRIPTION
The
.Fn hmac
function computes the key-Hash Message Authentication Code per
.Tn RFC 2104
and places the result in
.Fa digest
writing up to
.Fa dlen
bytes.
The actual number of bytes that would be written is returned.
.Pp
The hash functions supported are: md2, md4, md5, rmd160, sha1, sha224,
sha256, sha384, and sha512.
.Sh RETURN VALUES
The
.Fn hmac
function returns
.Dv \-1
if the
.Fa hname
is not found.
Otherwise the actual length of the digest string is returned (which could
be bigger or smaller than
.Fa dlen ) .
This length depends on the hashing function selected.
.Sh SEE ALSO
.Xr md2 3 ,
.Xr md4 3 ,
.Xr md5 3 ,
.Xr rmd160 3 ,
.Xr sha1 3 ,
.Xr sha2 3
.Sh STANDARDS
.Rs
.%R RFC 2104
.Re
.Sh NOTES
The maximum digest length has been extended from
.Dv 64
to
.Dv 128
bytes to handle SHA2.
.Sh HISTORY
The
.Fn hmac
function appeared in
.Nx 8 .