PROV: Add the beginning of a DER writing library

[thirdparty/openssl.git] / doc / internal / man3 / DER_w_precompiled.pod

=pod

=head1 NAME

DER_w_precompiled
- internal DER writers for precompiled DER blobs

=head1 SYNOPSIS

 #include "internal/der.h"

 int DER_w_precompiled(WPACKET *pkt, int tag,
                       const unsigned char *precompiled,
                       size_t precompiled_n);

=head1 DESCRIPTION

There may be already existing DER blobs that can simply be copied to
the buffer held by I<pkt>.  For example, precompiled values, such as
OIDs (for example, C<id-sha256>) or complete AlgorithmIdentifiers
(for example, C<sha256Identifier>).  To add those as an element in a
structure being DER encoded, use DER_w_precompiled().

DER_w_precompiled() will simply take the DER encoded blob given as
I<precompiled> with length I<precompiled_n> and add it to the buffer
held by I<pkt>.

=head1 RETURN VALUES

DER_w_precompiled() returns 1 on success and 0 on failure.  Failure
may mean that the buffer held by the I<pkt> is too small, but may also
mean that the values given to the functions are invalid, such as the provided
I<tag> value being too large for the implementation.

=head1 SEE ALSO

L<DERlib(7)>

=head1 COPYRIGHT

Copyright 2020 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