.\" $OpenBSD: BIO_dump.3,v 1.4 2022/12/20 15:34:03 schwarze Exp $
.\"
.\" Copyright (c) 2021 Ingo Schwarze <schwarze@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: December 20 2022 $
.Dt BIO_DUMP 3
.Os
.Sh NAME
.Nm BIO_dump ,
.Nm BIO_dump_indent ,
.Nm BIO_dump_fp ,
.Nm BIO_dump_indent_fp
.\" intentionally undocumented because nothing uses these two functions:
.\" .Nm BIO_dump_cb
.\" .Nm BIO_dump_indent_cb
.Nd hexadecimal printout of arbitrary byte arrays
.Sh SYNOPSIS
.In openssl/bio.h
.Ft int
.Fo BIO_dump
.Fa "BIO *b"
.Fa "const char *s"
.Fa "int len"
.Fc
.Ft int
.Fo BIO_dump_indent
.Fa "BIO *b"
.Fa "const char *s"
.Fa "int len"
.Fa "int indent"
.Fc
.Ft int
.Fo BIO_dump_fp
.Fa "FILE *fp"
.Fa "const char *s"
.Fa "int len"
.Fc
.Ft int
.Fo BIO_dump_indent_fp
.Fa "FILE *fp"
.Fa "const char *s"
.Fa "int len"
.Fa "int indent"
.Fc
.Sh DESCRIPTION
.Fn BIO_dump
prints
.Fa len
bytes starting at
.Fa s
to
.Fa bio
in hexadecimal format.
.Pp
The first column of output contains the index, in the byte array starting at
.Fa s ,
of the first byte shown on the respective output line, expressed as a
four-digit hexadecimal number starting at 0000, followed by a dash.
After the dash, sixteen bytes of data are printed as two-digit
hexadecimal numbers, respecting the order in which they appear in
the array
.Fa s .
Another dash is printed after the eighth column.
.Pp
To the right of the hexadecimal representation of the bytes,
the same bytes are printed again, this time as ASCII characters.
Non-printable ASCII characters are replaced with dots.
.Pp
Trailing space characters and NUL bytes are omitted from the main table.
If there are any, an additional line is printed, consisting of the
.Fa len
argument as a four-digit hexadecimal number, a dash, and the fixed string
.Qq <SPACES/NULS> .
.Pp
.Fn BIO_dump_indent
is similar except that
.Fa indent
space characters are prepended to each output line.
If
.Fa indent
is 7 or more, the number of data columns is reduced such that the
total width of the output does not exceed 79 characters per line.
.Pp
.Fn BIO_dump_fp
and
.Fn BIO_dump_indent_fp
are similar except that
.Xr fwrite 3
is used instead of
.Xr BIO_write 3 .
.Sh RETURN VALUES
On success these functions return the total number of bytes written by
.Xr BIO_write 3
or
.Xr fwrite 3 .
If a failure occurs at any point when writing, these
functions will stop after having potentially written out partial results,
and return -1.
.Sh SEE ALSO
.Xr hexdump 1 ,
.Xr BIO_new 3 ,
.Xr BIO_write 3
.Sh HISTORY
.Fn BIO_dump
first appeared in SSLeay 0.6.5 and has been available since
.Ox 2.4 .
.Pp
.Fn BIO_dump_indent
first appeared in OpenSSL 0.9.6 and has been available since
.Ox 2.9 .
.Pp
.Fn BIO_dump_fp
and
.Fn BIO_dump_indent_fp
first appeared in OpenSSL 0.9.8 and have been available since
.Ox 4.5 .