7 OSSL_ENCODER_settable_ctx_params,
8 OSSL_ENCODER_CTX_set_params,
10 OSSL_ENCODER_CTX_set_output_type,
11 OSSL_ENCODER_CTX_set_selection,
12 OSSL_ENCODER_CTX_add_encoder,
13 OSSL_ENCODER_CTX_add_extra,
14 OSSL_ENCODER_CTX_get_num_encoders,
15 OSSL_ENCODER_INSTANCE,
16 OSSL_ENCODER_INSTANCE_get_encoder,
17 OSSL_ENCODER_INSTANCE_get_encoder_ctx,
18 OSSL_ENCODER_INSTANCE_get_input_type,
19 OSSL_ENCODER_INSTANCE_get_output_type,
20 OSSL_ENCODER_CONSTRUCT,
22 OSSL_ENCODER_CTX_set_construct,
23 OSSL_ENCODER_CTX_set_construct_data,
24 OSSL_ENCODER_CTX_set_cleanup
25 - Encoder context routines
29 #include <openssl/encoder.h>
31 typedef struct ossl_encoder_ctx_st OSSL_ENCODER_CTX;
33 OSSL_ENCODER_CTX *OSSL_ENCODER_CTX_new();
34 const OSSL_PARAM *OSSL_ENCODER_settable_ctx_params(OSSL_ENCODER *encoder);
35 int OSSL_ENCODER_CTX_set_params(OSSL_ENCODER_CTX *ctx,
36 const OSSL_PARAM params[]);
37 void OSSL_ENCODER_CTX_free(OSSL_ENCODER_CTX *ctx);
39 int OSSL_ENCODER_CTX_set_output_type(OSSL_ENCODER_CTX *ctx,
40 const char *output_type);
41 int OSSL_ENCODER_CTX_set_selection(OSSL_ENCODER_CTX *ctx, int selection);
43 int OSSL_ENCODER_CTX_add_encoder(OSSL_ENCODER_CTX *ctx, OSSL_ENCODER *encoder);
44 int OSSL_ENCODER_CTX_add_extra(OSSL_ENCODER_CTX *ctx,
45 OPENSSL_CTX *libctx, const char *propq);
46 int OSSL_ENCODER_CTX_get_num_encoders(OSSL_ENCODER_CTX *ctx);
48 typedef struct ossl_encoder_instance_st OSSL_ENCODER_INSTANCE;
50 OSSL_ENCODER_INSTANCE_get_encoder(OSSL_ENCODER_INSTANCE *encoder_inst);
52 OSSL_ENCODER_INSTANCE_get_encoder_ctx(OSSL_ENCODER_INSTANCE *encoder_inst);
54 OSSL_ENCODER_INSTANCE_get_input_type(OSSL_ENCODER_INSTANCE *encoder_inst);
56 OSSL_ENCODER_INSTANCE_get_output_type(OSSL_ENCODER_INSTANCE *encoder_inst);
58 typedef const void *OSSL_ENCODER_CONSTRUCT(OSSL_ENCODER_INSTANCE *encoder_inst,
59 void *construct_data);
60 typedef void OSSL_ENCODER_CLEANUP(void *construct_data);
62 int OSSL_ENCODER_CTX_set_construct(OSSL_ENCODER_CTX *ctx,
63 OSSL_ENCODER_CONSTRUCT *construct);
64 int OSSL_ENCODER_CTX_set_construct_data(OSSL_ENCODER_CTX *ctx,
65 void *construct_data);
66 int OSSL_ENCODER_CTX_set_cleanup(OSSL_ENCODER_CTX *ctx,
67 OSSL_ENCODER_CLEANUP *cleanup);
71 Encoding an input object to the desired encoding may be done with a chain of
72 encoder implementations, which means that the output from one encoder may be
73 the input for the next in the chain. The B<OSSL_ENCODER_CTX> holds all the
74 data about these encoders. This allows having generic format encoders such
75 as DER to PEM, as well as more specialized encoders like RSA to DER.
77 The final output type must be given, and a chain of encoders must end with
78 an implementation that produces that output type.
80 At the beginning of the encoding process, a contructor provided by the
81 caller is called to ensure that there is an appropriate provider-side object
83 The constructor is set with OSSL_ENCODER_CTX_set_construct().
85 B<OSSL_ENCODER_INSTANCE> is an opaque structure that contains data about the
86 encoder that is going to be used, and that may be useful for the
87 constructor. There are some functions to extract data from this type,
88 described in L</Constructor> below.
92 OSSL_ENCODER_CTX_new() creates a B<OSSL_ENCODER_CTX>.
94 OSSL_ENCODER_settable_ctx_params() returns an L<OSSL_PARAM(3)>
95 array of parameter descriptors.
97 OSSL_ENCODER_CTX_set_params() attempts to set parameters specified
98 with an L<OSSL_PARAM(3)> array I<params>. Parameters that the
99 implementation doesn't recognise should be ignored.
101 OSSL_ENCODER_CTX_free() frees the given context I<ctx>.
103 OSSL_ENCODER_CTX_add_encoder() populates the B<OSSL_ENCODER_CTX>
104 I<ctx> with a encoder, to be used to encode an input object.
106 OSSL_ENCODER_CTX_add_extra() finds encoders that further encodes output
107 from already added encoders, and adds them as well. This is used to build
110 OSSL_ENCODER_CTX_set_output_type() sets the ending output type. This must
111 be specified, and determines if a complete encoder chain is available.
113 OSSL_ENCODER_CTX_num_encoders() gets the number of encoders currently added
114 to the context I<ctx>.
116 OSSL_ENCODER_CTX_set_construct() sets the constructor I<construct>.
118 OSSL_ENCODER_CTX_set_construct_data() sets the constructor data that is
119 passed to the constructor every time it's called.
121 OSSL_ENCODER_CTX_set_cleanup() sets the constructor data I<cleanup>
122 function. This is called by L<OSSL_ENCODER_CTX_free(3)>.
126 A B<OSSL_ENCODER_CONSTRUCT> gets the following arguments:
130 =item I<encoder_inst>
132 The B<OSSL_ENCODER_INSTANCE> for the encoder from which the constructor gets
135 =item I<construct_data>
137 The pointer that was set with OSSL_ENCODE_CTX_set_construct_data().
141 The constructor is expected to return a valid (non-NULL) pointer to a
142 provider-native object that can be used as first input of an encoding chain,
143 or NULL to indicate that an error has occured.
145 These utility functions may be used by a constructor:
147 OSSL_ENCODER_INSTANCE_encoder() can be used to get the encoder method from a
148 encoder instance I<encoder_inst>.
150 OSSL_ENCODER_INSTANCE_encoder_ctx() can be used to get the encoder method's
151 provider context from a encoder instance I<encoder_inst>.
153 OSSL_ENCODER_INSTANCE_input_type() can be used to get the input type for
154 encoder method from a encoder instance I<encoder_inst>. This may be NULL.
156 OSSL_ENCODER_INSTANCE_output_type() can be used to get the output type for
157 encoder method from a encoder instance I<encoder_inst>. This will never be
162 OSSL_ENCODER_CTX_new() returns a pointer to a B<OSSL_ENCODER_CTX>, or NULL
163 if the context structure couldn't be allocated.
165 OSSL_ENCODER_settable_ctx_params() returns an L<OSSL_PARAM(3)> array, or
166 NULL if none is available.
168 OSSL_ENCODER_CTX_set_params() returns 1 if all recognised parameters were
169 valid, or 0 if one of them was invalid or caused some other failure in the
172 OSSL_DECODER_CTX_add_decoder(), OSSL_DECODER_CTX_add_extra(),
173 OSSL_DECODER_CTX_set_construct(), OSSL_DECODER_CTX_set_construct_data() and
174 OSSL_DECODER_CTX_set_cleanup() return 1 on success, or 0 on failure.
176 OSSL_DECODER_CTX_num_decoders() returns the current number of decoders. It
177 returns 0 if I<ctx> is NULL.
179 OSSL_DECODER_INSTANCE_decoder() returns an B<OSSL_DECODER> pointer on
180 success, or NULL on failure.
182 OSSL_DECODER_INSTANCE_decoder_ctx() returns a provider context pointer on
183 success, or NULL on failure.
185 OSSL_ENCODER_INSTANCE_input_type() returns a string with the name of the
186 input type, if relevant. NULL is a valid returned value.
188 OSSL_ENCODER_INSTANCE_output_type() returns a string with the name of the
193 L<provider(7)>, L<OSSL_ENCODER(3)>
197 The functions described here were added in OpenSSL 3.0.
201 Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
203 Licensed under the Apache License 2.0 (the "License"). You may not use
204 this file except in compliance with the License. You can obtain a copy
205 in the file LICENSE in the source distribution or at
206 L<https://www.openssl.org/source/license.html>.