doc/man3/OSSL_ENCODER.pod

   1 =pod
   2
   3 =head1 NAME
   4
   5 OSSL_ENCODER,
   6 OSSL_ENCODER_fetch,
   7 OSSL_ENCODER_up_ref,
   8 OSSL_ENCODER_free,
   9 OSSL_ENCODER_provider,
  10 OSSL_ENCODER_properties,
  11 OSSL_ENCODER_is_a,
  12 OSSL_ENCODER_number,
  13 OSSL_ENCODER_do_all_provided,
  14 OSSL_ENCODER_names_do_all,
  15 OSSL_ENCODER_gettable_params,
  16 OSSL_ENCODER_get_params
  17 - Encoder method routines
  18
  19 =head1 SYNOPSIS
  20
  21  #include <openssl/encoder.h>
  22
  23  typedef struct ossl_encoder_st OSSL_ENCODER;
  24
  25  OSSL_ENCODER *OSSL_ENCODER_fetch(OSSL_LIB_CTX *ctx, const char *name,
  26                                   const char *properties);
  27  int OSSL_ENCODER_up_ref(OSSL_ENCODER *encoder);
  28  void OSSL_ENCODER_free(OSSL_ENCODER *encoder);
  29  const OSSL_PROVIDER *OSSL_ENCODER_provider(const OSSL_ENCODER *encoder);
  30  const char *OSSL_ENCODER_properties(const OSSL_ENCODER *encoder);
  31  int OSSL_ENCODER_is_a(const OSSL_ENCODER *encoder, const char *name);
  32  int OSSL_ENCODER_number(const OSSL_ENCODER *encoder);
  33  void OSSL_ENCODER_do_all_provided(OSSL_LIB_CTX *libctx,
  34                                    void (*fn)(OSSL_ENCODER *encoder, void *arg),
  35                                    void *arg);
  36  int OSSL_ENCODER_names_do_all(const OSSL_ENCODER *encoder,
  37                                void (*fn)(const char *name, void *data),
  38                                void *data);
  39  const OSSL_PARAM *OSSL_ENCODER_gettable_params(OSSL_ENCODER *encoder);
  40  int OSSL_ENCODER_get_params(OSSL_ENCODER_CTX *ctx, const OSSL_PARAM params[]);
  41
  42 =head1 DESCRIPTION
  43
  44 B<OSSL_ENCODER> is a method for encoders, which know how to
  45 encode an object of some kind to a encoded form, such as PEM,
  46 DER, or even human readable text.
  47
  48 OSSL_ENCODER_fetch() looks for an algorithm within the provider that
  49 has been loaded into the B<OSSL_LIB_CTX> given by I<ctx>, having the
  50 name given by I<name> and the properties given by I<properties>.
  51 The I<name> determines what type of object the fetched encoder
  52 method is expected to be able to encode, and the properties are
  53 used to determine the expected output type.
  54 For known properties and the values they may have, please have a look
  55 in L<provider-encoder(7)/Names and properties>.
  56
  57 OSSL_ENCODER_up_ref() increments the reference count for the given
  58 I<encoder>.
  59
  60 OSSL_ENCODER_free() decrements the reference count for the given
  61 I<encoder>, and when the count reaches zero, frees it.
  62
  63 OSSL_ENCODER_provider() returns the provider of the given
  64 I<encoder>.
  65
  66 OSSL_ENCODER_properties() returns the property definition associated
  67 with the given I<encoder>.
  68
  69 OSSL_ENCODER_is_a() checks if I<encoder> is an implementation of an
  70 algorithm that's identifiable with I<name>.
  71
  72 OSSL_ENCODER_number() returns the internal dynamic number assigned to
  73 the given I<encoder>.
  74
  75 OSSL_ENCODER_names_do_all() traverses all names for the given
  76 I<encoder>, and calls I<fn> with each name and I<data> as arguments.
  77
  78 OSSL_ENCODER_do_all_provided() traverses all encoder
  79 implementations by all activated providers in the library context
  80 I<libctx>, and for each of the implementations, calls I<fn> with the
  81 implementation method and I<arg> as arguments.
  82
  83 OSSL_ENCODER_gettable_params() returns an L<OSSL_PARAM(3)>
  84 array of parameter descriptors.
  85
  86 OSSL_ENCODER_get_params() attempts to get parameters specified
  87 with an L<OSSL_PARAM(3)> array I<params>.  Parameters that the
  88 implementation doesn't recognise should be ignored.
  89
  90 =head1 RETURN VALUES
  91
  92 OSSL_ENCODER_fetch() returns a pointer to the key management
  93 implementation represented by an OSSL_ENCODER object, or NULL on
  94 error.
  95
  96 OSSL_ENCODER_up_ref() returns 1 on success, or 0 on error.
  97
  98 OSSL_ENCODER_free() doesn't return any value.
  99
 100 OSSL_ENCODER_provider() returns a pointer to a provider object, or
 101 NULL on error.
 102
 103 OSSL_ENCODER_properties() returns a pointer to a property
 104 definition string, or NULL on error.
 105
 106 OSSL_ENCODER_is_a() returns 1 of I<encoder> was identifiable,
 107 otherwise 0.
 108
 109 OSSL_ENCODER_number() returns an integer.
 110
 111 OSSL_ENCODER_names_do_all() returns 1 if the callback was called for all
 112 names. A return value of 0 means that the callback was not called for any names.
 113
 114 =head1 SEE ALSO
 115
 116 L<provider(7)>, L<OSSL_ENCODER_CTX(3)>, L<OSSL_ENCODER_to_bio(3)>,
 117 L<OSSL_ENCODER_CTX_new_for_pkey(3)>, L<OSSL_LIB_CTX(3)>
 118
 119 =head1 HISTORY
 120
 121 The functions described here were added in OpenSSL 3.0.
 122
 123 =head1 COPYRIGHT
 124
 125 Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
 126
 127 Licensed under the Apache License 2.0 (the "License").  You may not use
 128 this file except in compliance with the License.  You can obtain a copy
 129 in the file LICENSE in the source distribution or at
 130 L<https://www.openssl.org/source/license.html>.
 131
 132 =cut