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.Dd May 1, 2022
.Dt BASE64 3
.Os
.Sh NAME
.Nm base64 ,
.Nm b64_ntop ,
.Nm b64_pton
.Nd base64 encode and decode
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In resolv.h
.Ft int
.Fo b64_ntop
.Fa "const unsigned char *src"
.Fa "size_t srclength"
.Fa "char *target"
.Fa "size_t targsize"
.Fc
.Ft int
.Fo b64_pton
.Fa "const char *src"
.Fa "unsigned char *target"
.Fa "size_t targsize"
.Fc
.Sh DESCRIPTION
.Fn B64_ntop
encodes the input data
.Fa src
of length
.Fa srclength ,
and writes the encoded string to
.Fa target
of capacity
.Fa targsize .
The output buffer
.Fa target
should be big enough to hold the encoded string,
including the terminating NUL character.
On success,
.Fa target
holds the encoded string and its length
(without accounting for the NUL terminator) is returned.
Otherwise, a value of \-1 is returned.
.Pp
.Fn B64_pton
decodes the base64 string
.Fa src
and writes the decoded data to
.Fa target
of capacity
.Fa targsize .
On success,
.Fa target
holds the decoded data and its length is returned.
Otherwise, a value of \-1 is returned.
If the output buffer
.Fa target
is
.Dv NULL ,
.Fn b64_pton
returns the required length to hold the decoded data.
.Sh RETURN VALUES
The
.Nm base64
functions return the length of the result if successful;
otherwise the value \-1 is returned.
.Sh SEE ALSO
.Xr openssl 1
.Rs
.%R RFC
.%N 1521
.%D September 1993
.%T "MIME (Multipurpose Internet Mail Extensions) Part One"
.Re
.Sh HISTORY
The
.Nm base64
functions appeared in
.Fx 3.0 .
.Sh AUTHORS
.An -nosplit
This manual page was written by
.An Aaron LI Aq Mt aly@aaronly.me .