xref: /openssl/doc/man3/OSSL_ENCODER.pod (revision 7ed6de99)
1=pod
2
3=head1 NAME
4
5OSSL_ENCODER,
6OSSL_ENCODER_fetch,
7OSSL_ENCODER_up_ref,
8OSSL_ENCODER_free,
9OSSL_ENCODER_get0_provider,
10OSSL_ENCODER_get0_properties,
11OSSL_ENCODER_is_a,
12OSSL_ENCODER_get0_name,
13OSSL_ENCODER_get0_description,
14OSSL_ENCODER_do_all_provided,
15OSSL_ENCODER_names_do_all,
16OSSL_ENCODER_gettable_params,
17OSSL_ENCODER_get_params
18- Encoder method routines
19
20=head1 SYNOPSIS
21
22 #include <openssl/encoder.h>
23
24 typedef struct ossl_encoder_st OSSL_ENCODER;
25
26 OSSL_ENCODER *OSSL_ENCODER_fetch(OSSL_LIB_CTX *ctx, const char *name,
27                                  const char *properties);
28 int OSSL_ENCODER_up_ref(OSSL_ENCODER *encoder);
29 void OSSL_ENCODER_free(OSSL_ENCODER *encoder);
30 const OSSL_PROVIDER *OSSL_ENCODER_get0_provider(const OSSL_ENCODER *encoder);
31 const char *OSSL_ENCODER_get0_properties(const OSSL_ENCODER *encoder);
32 int OSSL_ENCODER_is_a(const OSSL_ENCODER *encoder, const char *name);
33 const char *OSSL_ENCODER_get0_name(const OSSL_ENCODER *encoder);
34 const char *OSSL_ENCODER_get0_description(const OSSL_ENCODER *encoder);
35 void OSSL_ENCODER_do_all_provided(OSSL_LIB_CTX *libctx,
36                                   void (*fn)(OSSL_ENCODER *encoder, void *arg),
37                                   void *arg);
38 int OSSL_ENCODER_names_do_all(const OSSL_ENCODER *encoder,
39                               void (*fn)(const char *name, void *data),
40                               void *data);
41 const OSSL_PARAM *OSSL_ENCODER_gettable_params(OSSL_ENCODER *encoder);
42 int OSSL_ENCODER_get_params(OSSL_ENCODER_CTX *ctx, const OSSL_PARAM params[]);
43
44=head1 DESCRIPTION
45
46B<OSSL_ENCODER> is a method for encoders, which know how to
47encode an object of some kind to a encoded form, such as PEM,
48DER, or even human readable text.
49
50OSSL_ENCODER_fetch() looks for an algorithm within the provider that
51has been loaded into the B<OSSL_LIB_CTX> given by I<ctx>, having the
52name given by I<name> and the properties given by I<properties>.
53The I<name> determines what type of object the fetched encoder
54method is expected to be able to encode, and the properties are
55used to determine the expected output type.
56For known properties and the values they may have, please have a look
57in L<provider-encoder(7)/Names and properties>.
58
59OSSL_ENCODER_up_ref() increments the reference count for the given
60I<encoder>.
61
62OSSL_ENCODER_free() decrements the reference count for the given
63I<encoder>, and when the count reaches zero, frees it.
64If the argument is NULL, nothing is done.
65
66OSSL_ENCODER_get0_provider() returns the provider of the given
67I<encoder>.
68
69OSSL_ENCODER_get0_properties() returns the property definition associated
70with the given I<encoder>.
71
72OSSL_ENCODER_is_a() checks if I<encoder> is an implementation of an
73algorithm that's identifiable with I<name>.
74
75OSSL_ENCODER_get0_name() returns the name used to fetch the given I<encoder>.
76
77OSSL_ENCODER_get0_description() returns a description of the I<loader>, meant
78for display and human consumption.  The description is at the discretion of the
79I<loader> implementation.
80
81OSSL_ENCODER_names_do_all() traverses all names for the given
82I<encoder>, and calls I<fn> with each name and I<data> as arguments.
83
84OSSL_ENCODER_do_all_provided() traverses all encoder
85implementations by all activated providers in the library context
86I<libctx>, and for each of the implementations, calls I<fn> with the
87implementation method and I<arg> as arguments.
88
89OSSL_ENCODER_gettable_params() returns an L<OSSL_PARAM(3)>
90array of parameter descriptors.
91
92OSSL_ENCODER_get_params() attempts to get parameters specified
93with an L<OSSL_PARAM(3)> array I<params>.  Parameters that the
94implementation doesn't recognise should be ignored.
95
96=head1 RETURN VALUES
97
98OSSL_ENCODER_fetch() returns a pointer to the key management
99implementation represented by an OSSL_ENCODER object, or NULL on
100error.
101
102OSSL_ENCODER_up_ref() returns 1 on success, or 0 on error.
103
104OSSL_ENCODER_free() doesn't return any value.
105
106OSSL_ENCODER_get0_provider() returns a pointer to a provider object, or
107NULL on error.
108
109OSSL_ENCODER_get0_properties() returns a pointer to a property
110definition string, or NULL on error.
111
112OSSL_ENCODER_is_a() returns 1 of I<encoder> was identifiable,
113otherwise 0.
114
115OSSL_ENCODER_get0_name() returns the algorithm name from the provided
116implementation for the given I<encoder>. Note that the I<encoder> may have
117multiple synonyms associated with it. In this case the first name from the
118algorithm definition is returned. Ownership of the returned string is retained
119by the I<encoder> object and should not be freed by the caller.
120
121OSSL_ENCODER_get0_description() returns a pointer to a description, or NULL if
122there isn't one.
123
124OSSL_ENCODER_names_do_all() returns 1 if the callback was called for all
125names. A return value of 0 means that the callback was not called for any names.
126
127=head1 SEE ALSO
128
129L<provider(7)>, L<OSSL_ENCODER_CTX(3)>, L<OSSL_ENCODER_to_bio(3)>,
130L<OSSL_ENCODER_CTX_new_for_pkey(3)>, L<OSSL_LIB_CTX(3)>
131
132=head1 HISTORY
133
134The functions described here were added in OpenSSL 3.0.
135
136=head1 COPYRIGHT
137
138Copyright 2019-2024 The OpenSSL Project Authors. All Rights Reserved.
139
140Licensed under the Apache License 2.0 (the "License").  You may not use
141this file except in compliance with the License.  You can obtain a copy
142in the file LICENSE in the source distribution or at
143L<https://www.openssl.org/source/license.html>.
144
145=cut
146