=pod

=head1 NAME

openssl-format-options - OpenSSL command input and output format options

=head1 SYNOPSIS

B<openssl>
I<command>
[ I<options> ... ]
[ I<parameters> ... ]

=head1 DESCRIPTION

Several OpenSSL commands can take input or generate output in a variety
of formats.

Since OpenSSL 3.0 keys, single certificates, and CRLs can be read from
files in any of the B<DER>, B<PEM> or B<P12> formats. Specifying their input
format is no more needed and the openssl commands will automatically try all
the possible formats. However if the B<DER> or B<PEM> input format is specified
it will be enforced.

=head1 OPTIONS

=head2 Format Options

The options to specify the format are as follows.
Refer to the individual man page to see which options are accepted.

=over 4

=item B<-inform> I<format>, B<-outform> I<format>

The format of the input or output streams.

=item B<-keyform> I<format>

Format of a private key input source.

=item B<-CRLform> I<format>

Format of a CRL input source.

=back

=head2 Format Option Arguments

The possible format arguments are described below.
Both uppercase and lowercase are accepted.

The list of acceptable format arguments, and the default,
is described in each command documentation.

=over 4

=item B<DER>

A binary format, encoded or parsed according to Distinguished Encoding Rules
(DER) of the ASN.1 data language.

=item B<P12>

A DER-encoded file containing a PKCS#12 object.
It might be necessary to provide a decryption password to retrieve
the private key or certificate.

=item B<PEM>

A text format defined in IETF RFC 1421 and IETF RFC 7468. Briefly, this is
a block of base-64 encoding (defined in IETF RFC 4648), with specific
lines used to mark the start and end:

 Text before the BEGIN line is ignored.
 -----BEGIN object-type-----
 OT43gQKBgQC/2OHZoko6iRlNOAQ/tMVFNq7fL81GivoQ9F1U0Qr+DH3ZfaH8eIkX
 xT0ToMPJUzWAn8pZv0snA0um6SIgvkCuxO84OkANCVbttzXImIsL7pFzfcwV/ERK
 UM6j0ZuSMFOCr/lGPAoOQU0fskidGEHi1/kW+suSr28TqsyYZpwBDQ==
 -----END object-type-----
 Text after the END line is also ignored

The I<object-type> must match the type of object that is expected.
For example a C<BEGIN X509 CERTIFICATE> will not match if the command
is trying to read a private key. The types supported include:

 ANY PRIVATE KEY
 CERTIFICATE
 CERTIFICATE REQUEST
 CMS
 DH PARAMETERS
 DSA PARAMETERS
 DSA PUBLIC KEY
 EC PARAMETERS
 EC PRIVATE KEY
 ECDSA PUBLIC KEY
 ENCRYPTED PRIVATE KEY
 PARAMETERS
 PKCS #7 SIGNED DATA
 PKCS7
 PRIVATE KEY
 PUBLIC KEY
 RSA PRIVATE KEY
 SSL SESSION PARAMETERS
 TRUSTED CERTIFICATE
 X509 CRL
 X9.42 DH PARAMETERS

The following legacy I<object-type>'s are also supported for compatibility
with earlier releases:

 DSA PRIVATE KEY
 NEW CERTIFICATE REQUEST
 RSA PUBLIC KEY
 X509 CERTIFICATE

=item B<SMIME>

An S/MIME object as described in IETF RFC 8551.
Earlier versions were known as CMS and are compatible.
Note that the parsing is simple and might fail to parse some legal data.

=back

=head1 COPYRIGHT

Copyright 2000-2026 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.

=cut
