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=head1 NAME

OSSL_DECODER_CTX,
OSSL_DECODER_CTX_new,
OSSL_DECODER_settable_ctx_params,
OSSL_DECODER_CTX_set_params,
OSSL_DECODER_CTX_free
- Encoder context routines

=head1 SYNOPSIS

 #include <openssl/decoder.h>

 typedef struct ossl_decoder_ctx_st OSSL_DECODER_CTX;

 OSSL_DECODER_CTX *OSSL_DECODER_CTX_new(OPENSSL_CTX *libctx);
 const OSSL_PARAM *OSSL_DECODER_settable_ctx_params(OSSL_DECODER *decoder);
 int OSSL_DECODER_CTX_set_params(OSSL_DECODER_CTX *ctx,
                                 const OSSL_PARAM params[]);
 void OSSL_DECODER_CTX_free(OSSL_DECODER_CTX *ctx);

=head1 DESCRIPTION

B<OSSL_DECODER_CTX> is a context with which B<OSSL_DECODER>
operations are performed.  The context typically holds values, both
internal and supplied by the application, which are useful for the
implementations supplied by providers.

OSSL_DECODER_CTX_new() creates a new empty B<OSSL_DECODER_CTX>.

OSSL_DECODER_settable_ctx_params() returns an L<OSSL_PARAM(3)>
array of parameter descriptors.

OSSL_DECODER_CTX_set_params() attempts to set parameters specified
with an L<OSSL_PARAM(3)> array I<params>.  These parameters are passed
to all decoders that have been added to the I<ctx> so far.
Parameters that an implementation doesn't recognise should be ignored
by it.

OSSL_DECODER_CTX_free() frees the given context I<ctx>.

=head1 RETURN VALUES

OSSL_DECODER_CTX_new() returns a pointer to a
B<OSSL_DECODER_CTX>, or NULL if the context structure couldn't be
allocated.

OSSL_DECODER_settable_ctx_params() returns an L<OSSL_PARAM(3)>
array, or NULL if none is available.

OSSL_DECODER_CTX_set_params() returns 1 if all recognised
parameters were valid, or 0 if one of them was invalid or caused some
other failure in the implementation.

=head1 SEE ALSO

L<provider(7)>, L<OSSL_DECODER(3)>, L<OSSL_DECODER_from_bio(3)>

=head1 HISTORY

The functions described here were added in OpenSSL 3.0.

=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>.

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