PROV: Add the beginning of a DER writing library

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

diff --git a/doc/internal/man3/DER_w_begin_sequence.pod b/doc/internal/man3/DER_w_begin_sequence.pod
new file mode 100644 (file)
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+++ b/doc/internal/man3/DER_w_begin_sequence.pod
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+=pod
+
+=head1 NAME
+
+DER_w_begin_sequence, DER_w_end_sequence
+- internal DER writers for DER constructed elements
+
+=head1 SYNOPSIS
+
+ #include "internal/der.h"
+
+ int DER_w_begin_sequence(WPACKET *pkt, int tag);
+ int DER_w_end_sequence(WPACKET *pkt, int tag);
+
+=head1 DESCRIPTION
+
+All functions described here are wrappers for constructed structures,
+i.e. the ASN.1 SEQUENCE, SET and CHOICE specifications.  They all come
+in pairs, as noted by the function names containing the words C<begin>
+and B<end>.
+
+When using these, special care must be taken to ensure that the ASN.1 tag
+value I<tag> is the same in the matching C<begin> and C<end> function calls.
+
+DER_w_begin_sequence() and DER_w_end_sequence() begins and ends a
+SEQUENCE.
+
+=head1 RETURN VALUES
+
+All the functions return 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