NAME

       OSSL_ENCODER, OSSL_ENCODER_fetch, OSSL_ENCODER_up_ref, OSSL_ENCODER_free,
       OSSL_ENCODER_get0_provider, OSSL_ENCODER_get0_properties, OSSL_ENCODER_is_a,
       OSSL_ENCODER_get0_name, OSSL_ENCODER_get0_description, OSSL_ENCODER_do_all_provided,
       OSSL_ENCODER_names_do_all, OSSL_ENCODER_gettable_params, OSSL_ENCODER_get_params - Encoder
       method routines

SYNOPSIS

        #include <openssl/encoder.h>

        typedef struct ossl_encoder_st OSSL_ENCODER;

        OSSL_ENCODER *OSSL_ENCODER_fetch(OSSL_LIB_CTX *ctx, const char *name,
                                         const char *properties);
        int OSSL_ENCODER_up_ref(OSSL_ENCODER *encoder);
        void OSSL_ENCODER_free(OSSL_ENCODER *encoder);
        const OSSL_PROVIDER *OSSL_ENCODER_get0_provider(const OSSL_ENCODER *encoder);
        const char *OSSL_ENCODER_get0_properties(const OSSL_ENCODER *encoder);
        int OSSL_ENCODER_is_a(const OSSL_ENCODER *encoder, const char *name);
        const char *OSSL_ENCODER_get0_name(const OSSL_ENCODER *encoder);
        const char *OSSL_ENCODER_get0_description(const OSSL_ENCODER *encoder);
        void OSSL_ENCODER_do_all_provided(OSSL_LIB_CTX *libctx,
                                          void (*fn)(OSSL_ENCODER *encoder, void *arg),
                                          void *arg);
        int OSSL_ENCODER_names_do_all(const OSSL_ENCODER *encoder,
                                      void (*fn)(const char *name, void *data),
                                      void *data);
        const OSSL_PARAM *OSSL_ENCODER_gettable_params(OSSL_ENCODER *encoder);
        int OSSL_ENCODER_get_params(OSSL_ENCODER_CTX *ctx, const OSSL_PARAM params[]);

DESCRIPTION

       OSSL_ENCODER is a method for encoders, which know how to encode an object of some kind to
       a encoded form, such as PEM, DER, or even human readable text.

       OSSL_ENCODER_fetch() looks for an algorithm within the provider that has been loaded into
       the OSSL_LIB_CTX given by ctx, having the name given by name and the properties given by
       properties.  The name determines what type of object the fetched encoder method is
       expected to be able to encode, and the properties are used to determine the expected
       output type.  For known properties and the values they may have, please have a look in
       "Names and properties" in provider-encoder(7).

       OSSL_ENCODER_up_ref() increments the reference count for the given encoder.

       OSSL_ENCODER_free() decrements the reference count for the given encoder, and when the
       count reaches zero, frees it.

       OSSL_ENCODER_get0_provider() returns the provider of the given encoder.

       OSSL_ENCODER_get0_properties() returns the property definition associated with the given
       encoder.

       OSSL_ENCODER_is_a() checks if encoder is an implementation of an algorithm that's
       identifiable with name.

       OSSL_ENCODER_get0_name() returns the name used to fetch the given encoder.

       OSSL_ENCODER_get0_description() returns a description of the loader, meant for display and
       human consumption.  The description is at the discretion of the loader implementation.

       OSSL_ENCODER_names_do_all() traverses all names for the given encoder, and calls fn with
       each name and data as arguments.

       OSSL_ENCODER_do_all_provided() traverses all encoder implementations by all activated
       providers in the library context libctx, and for each of the implementations, calls fn
       with the implementation method and arg as arguments.

       OSSL_ENCODER_gettable_params() returns an OSSL_PARAM(3) array of parameter descriptors.

       OSSL_ENCODER_get_params() attempts to get parameters specified with an OSSL_PARAM(3) array
       params.  Parameters that the implementation doesn't recognise should be ignored.

RETURN VALUES

       OSSL_ENCODER_fetch() returns a pointer to the key management implementation represented by
       an OSSL_ENCODER object, or NULL on error.

       OSSL_ENCODER_up_ref() returns 1 on success, or 0 on error.

       OSSL_ENCODER_free() doesn't return any value.

       OSSL_ENCODER_get0_provider() returns a pointer to a provider object, or NULL on error.

       OSSL_ENCODER_get0_properties() returns a pointer to a property definition string, or NULL
       on error.

       OSSL_ENCODER_is_a() returns 1 of encoder was identifiable, otherwise 0.

       OSSL_ENCODER_get0_name() returns the algorithm name from the provided implementation for
       the given encoder. Note that the encoder may have multiple synonyms associated with it. In
       this case the first name from the algorithm definition is returned. Ownership of the
       returned string is retained by the encoder object and should not be freed by the caller.

       OSSL_ENCODER_get0_description() returns a pointer to a description, or NULL if there isn't
       one.

       OSSL_ENCODER_names_do_all() returns 1 if the callback was called for all names. A return
       value of 0 means that the callback was not called for any names.

SEE ALSO

       provider(7), OSSL_ENCODER_CTX(3), OSSL_ENCODER_to_bio(3),
       OSSL_ENCODER_CTX_new_for_pkey(3), OSSL_LIB_CTX(3)

HISTORY

       The functions described here were added in OpenSSL 3.0.

COPYRIGHT

       Copyright 2019-2023 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 <https://www.openssl.org/source/license.html>.