5 provider-keymgmt - The KEYMGMT library E<lt>-E<gt> provider functions
9 #include <openssl/core_dispatch.h>
12 * None of these are actual functions, but are displayed like this for
13 * the function signatures for functions that are offered as function
14 * pointers in OSSL_DISPATCH arrays.
17 /* Key object (keydata) creation and destruction */
18 void *OSSL_FUNC_keymgmt_new(void *provctx);
19 void OSSL_FUNC_keymgmt_free(void *keydata);
21 void *OSSL_FUNC_keymgmt_gen_init(void *provctx, int selection);
22 int OSSL_FUNC_keymgmt_gen_set_template(void *genctx, void *template);
23 int OSSL_FUNC_keymgmt_gen_set_params(void *genctx, const OSSL_PARAM params[]);
24 const OSSL_PARAM *OSSL_FUNC_keymgmt_gen_settable_params(void *provctx);
25 void *OSSL_FUNC_keymgmt_gen(void *genctx, OSSL_CALLBACK *cb, void *cbarg);
26 void OSSL_FUNC_keymgmt_gen_cleanup(void *genctx);
28 /* Key object information */
29 int OSSL_FUNC_keymgmt_get_params(void *keydata, OSSL_PARAM params[]);
30 const OSSL_PARAM *OSSL_FUNC_keymgmt_gettable_params(void);
31 int OSSL_FUNC_keymgmt_set_params(void *keydata, const OSSL_PARAM params[]);
32 const OSSL_PARAM *OSSL_FUNC_keymgmt_settable_params(void);
34 /* Key object content checks */
35 int OSSL_FUNC_keymgmt_has(void *keydata, int selection);
36 int OSSL_FUNC_keymgmt_match(const void *keydata1, const void *keydata2,
39 /* Discovery of supported operations */
40 const char *OSSL_FUNC_keymgmt_query_operation_name(int operation_id);
42 /* Key object import and export functions */
43 int OSSL_FUNC_keymgmt_import(int selection, void *keydata, const OSSL_PARAM params[]);
44 const OSSL_PARAM *OSSL_FUNC_keymgmt_import_types(int selection);
45 int OSSL_FUNC_keymgmt_export(int selection, void *keydata,
46 OSSL_CALLBACK *param_cb, void *cbarg);
47 const OSSL_PARAM *OSSL_FUNC_keymgmt_export_types(int selection);
50 int OSSL_FUNC_keymgmt_copy(void *keydata_to, const void *keydata_from, int selection);
52 /* Key object validation */
53 int OSSL_FUNC_keymgmt_validate(void *keydata, int selection);
57 The KEYMGMT operation doesn't have much public visibility in OpenSSL
58 libraries, it's rather an internal operation that's designed to work
59 in tandem with operations that use private/public key pairs.
61 Because the KEYMGMT operation shares knowledge with the operations it
62 works with in tandem, they must belong to the same provider.
63 The OpenSSL libraries will ensure that they do.
65 The primary responsibility of the KEYMGMT operation is to hold the
66 provider side key data for the OpenSSL library EVP_PKEY structure.
68 All "functions" mentioned here are passed as function pointers between
69 F<libcrypto> and the provider in B<OSSL_DISPATCH> arrays via
70 B<OSSL_ALGORITHM> arrays that are returned by the provider's
71 provider_query_operation() function
72 (see L<provider-base(7)/Provider Functions>).
74 All these "functions" have a corresponding function type definition
75 named B<OSSL_{name}_fn>, and a helper function to retrieve the
76 function pointer from a B<OSSL_DISPATCH> element named
78 For example, the "function" OSSL_FUNC_keymgmt_new() has these:
80 typedef void *(OSSL_FUNC_keymgmt_new_fn)(void *provctx);
81 static ossl_inline OSSL_FUNC_keymgmt_new_fn
82 OSSL_FUNC_keymgmt_new(const OSSL_DISPATCH *opf);
84 B<OSSL_DISPATCH> arrays are indexed by numbers that are provided as
85 macros in L<openssl-core_dispatch.h(7)>, as follows:
87 OSSL_FUNC_keymgmt_new OSSL_FUNC_KEYMGMT_NEW
88 OSSL_FUNC_keymgmt_free OSSL_FUNC_KEYMGMT_FREE
90 OSSL_FUNC_keymgmt_gen_init OSSL_FUNC_KEYMGMT_GEN_INIT
91 OSSL_FUNC_keymgmt_gen_set_template OSSL_FUNC_KEYMGMT_GEN_SET_TEMPLATE
92 OSSL_FUNC_keymgmt_gen_set_params OSSL_FUNC_KEYMGMT_GEN_SET_PARAMS
93 OSSL_FUNC_keymgmt_gen_settable_params OSSL_FUNC_KEYMGMT_GEN_SETTABLE_PARAMS
94 OSSL_FUNC_keymgmt_gen OSSL_FUNC_KEYMGMT_GEN
95 OSSL_FUNC_keymgmt_gen_cleanup OSSL_FUNC_KEYMGMT_GEN_CLEANUP
97 OSSL_FUNC_keymgmt_get_params OSSL_FUNC_KEYMGMT_GET_PARAMS
98 OSSL_FUNC_keymgmt_gettable_params OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS
99 OSSL_FUNC_keymgmt_set_params OSSL_FUNC_KEYMGMT_SET_PARAMS
100 OSSL_FUNC_keymgmt_settable_params OSSL_FUNC_KEYMGMT_SETTABLE_PARAMS
102 OSSL_FUNC_keymgmt_query_operation_name OSSL_FUNC_KEYMGMT_QUERY_OPERATION_NAME
104 OSSL_FUNC_keymgmt_has OSSL_FUNC_KEYMGMT_HAS
105 OSSL_FUNC_keymgmt_validate OSSL_FUNC_KEYMGMT_VALIDATE
106 OSSL_FUNC_keymgmt_match OSSL_FUNC_KEYMGMT_MATCH
108 OSSL_FUNC_keymgmt_import OSSL_FUNC_KEYMGMT_IMPORT
109 OSSL_FUNC_keymgmt_import_types OSSL_FUNC_KEYMGMT_IMPORT_TYPES
110 OSSL_FUNC_keymgmt_export OSSL_FUNC_KEYMGMT_EXPORT
111 OSSL_FUNC_keymgmt_export_types OSSL_FUNC_KEYMGMT_EXPORT_TYPES
113 OSSL_FUNC_keymgmt_copy OSSL_FUNC_KEYMGMT_COPY
117 A key object is a collection of data for an asymmetric key, and is
118 represented as I<keydata> in this manual.
120 The exact contents of a key object are defined by the provider, and it
121 is assumed that different operations in one and the same provider use
122 the exact same structure to represent this collection of data, so that
123 for example, a key object that has been created using the KEYMGMT
124 interface that we document here can be passed as is to other provider
125 operations, such as OP_signature_sign_init() (see
126 L<provider-signature(7)>).
128 With some of the KEYMGMT functions, it's possible to select a specific
129 subset of data to handle, governed by the bits in a I<selection>
130 indicator. The bits are:
134 =item B<OSSL_KEYMGMT_SELECT_PRIVATE_KEY>
136 Indicating that the private key data in a key object should be
139 =item B<OSSL_KEYMGMT_SELECT_PUBLIC_KEY>
141 Indicating that the public key data in a key object should be
144 =item B<OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS>
146 Indicating that the domain parameters in a key object should be
149 =item B<OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS>
151 Indicating that other parameters in a key object should be
154 Other parameters are key parameters that don't fit any other
155 classification. In other words, this particular selector bit works as
156 a last resort bit bucket selector.
160 Some selector bits have also been combined for easier use:
164 =item B<OSSL_KEYMGMT_SELECT_ALL_PARAMETERS>
166 Indicating that all key object parameters should be considered,
167 regardless of their more granular classification.
169 =for comment This should used by EVP functions such as
170 EVP_PKEY_copy_parameters() and EVP_PKEY_cmp_parameters()
172 This is a combination of B<OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS> and
173 B<OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS>.
175 =for comment If more parameter categories are added, they should be
178 =item B<OSSL_KEYMGMT_SELECT_KEYPAIR>
180 Indicating that both the whole key pair in a key object should be
181 considered, i.e. the combination of public and private key.
183 This is a combination of B<OSSL_KEYMGMT_SELECT_PRIVATE_KEY> and
184 B<OSSL_KEYMGMT_SELECT_PUBLIC_KEY>.
186 =item B<OSSL_KEYMGMT_SELECT_ALL>
188 Indicating that everything in a key object should be considered.
192 The exact interpretation of those bits or how they combine is left to
193 each function where you can specify a selector.
195 =for comment One might think that a combination of bits means that all
196 the selected data subsets must be considered, but then you have to
197 consider that when comparing key objects (future function), an
198 implementation might opt to not compare the private key if it has
199 compared the public key, since a match of one half implies a match of
202 =head2 Constructing and Destructing Functions
204 OSSL_FUNC_keymgmt_new() should create a provider side key object. The
205 provider context I<provctx> is passed and may be incorporated in the
206 key object, but that is not mandatory.
208 OSSL_FUNC_keymgmt_free() should free the passed I<keydata>.
210 OSSL_FUNC_keymgmt_gen_init(), OSSL_FUNC_keymgmt_gen_set_template(),
211 OSSL_FUNC_keymgmt_gen_set_params(), OSSL_FUNC_keymgmt_gen_settable_params(),
212 OSSL_FUNC_keymgmt_gen() and OSSL_FUNC_keymgmt_gen_cleanup() work together as a more
213 elaborate context based key object constructor.
215 OSSL_FUNC_keymgmt_gen_init() should create the key object generation context
216 and initialize it with I<selections>, which will determine what kind
217 of contents the key object to be generated should get.
219 OSSL_FUNC_keymgmt_gen_set_template() should add I<template> to the context
220 I<genctx>. The I<template> is assumed to be a key object constructed
221 with the same KEYMGMT, and from which content that the implementation
222 chooses can be used as a template for the key object to be generated.
223 Typically, the generation of a DSA or DH key would get the domain
224 parameters from this I<template>.
226 OSSL_FUNC_keymgmt_gen_set_params() should set additional parameters from
227 I<params> in the key object generation context I<genctx>.
229 OSSL_FUNC_keymgmt_gen_settable_params() should return a constant array of
230 descriptor B<OSSL_PARAM>, for parameters that OSSL_FUNC_keymgmt_gen_set_params()
233 OSSL_FUNC_keymgmt_gen() should perform the key object generation itself, and
234 return the result. The callback I<cb> should be called at regular
235 intervals with indications on how the key object generation
238 OSSL_FUNC_keymgmt_gen_cleanup() should clean up and free the key object
239 generation context I<genctx>
241 At least one of OSSL_FUNC_keymgmt_new() and OSSL_FUNC_keymgmt_gen() are mandatory,
242 as well as OSSL_FUNC_keymgmt_free(). Additionally, if OSSL_FUNC_keymgmt_gen() is
243 present, OSSL_FUNC_keymgmt_gen_init() and OSSL_FUNC_keymgmt_gen_cleanup() must be
246 =head2 Key Object Information Functions
248 OSSL_FUNC_keymgmt_get_params() should extract information data associated
249 with the given I<keydata>, see L</Common Information Parameters>.
251 OSSL_FUNC_keymgmt_gettable_params() should return a constant array of
252 descriptor B<OSSL_PARAM>, for parameters that OSSL_FUNC_keymgmt_get_params()
255 If OSSL_FUNC_keymgmt_gettable_params() is present, OSSL_FUNC_keymgmt_get_params()
256 must also be present, and vice versa.
258 OSSL_FUNC_keymgmt_set_params() should update information data associated
259 with the given I<keydata>, see L</Common Information Parameters>.
261 OSSL_FUNC_keymgmt_settable_params() should return a constant array of
262 descriptor B<OSSL_PARAM>, for parameters that OSSL_FUNC_keymgmt_set_params()
265 If OSSL_FUNC_keymgmt_settable_params() is present, OSSL_FUNC_keymgmt_set_params()
266 must also be present, and vice versa.
268 =head2 Key Object Checking Functions
270 OSSL_FUNC_keymgmt_query_operation_name() should return the name of the
271 supported algorithm for the operation I<operation_id>. This is
272 similar to provider_query_operation() (see L<provider-base(7)>),
273 but only works as an advisory. If this function is not present, or
274 returns NULL, the caller is free to assume that there's an algorithm
275 from the same provider, of the same name as the one used to fetch the
276 keymgmt and try to use that.
278 OSSL_FUNC_keymgmt_has() should check whether the given I<keydata> contains the subsets
279 of data indicated by the I<selector>. A combination of several
280 selector bits must consider all those subsets, not just one. An
281 implementation is, however, free to consider an empty subset of data
282 to still be a valid subset.
284 OSSL_FUNC_keymgmt_validate() should check if the I<keydata> contains valid
285 data subsets indicated by I<selection>. Some combined selections of
286 data subsets may cause validation of the combined data.
287 For example, the combination of B<OSSL_KEYMGMT_SELECT_PRIVATE_KEY> and
288 B<OSSL_KEYMGMT_SELECT_PUBLIC_KEY> (or B<OSSL_KEYMGMT_SELECT_KEYPAIR>
289 for short) is expected to check that the pairwise consistency of
292 OSSL_FUNC_keymgmt_match() should check if the data subset indicated by
293 I<selection> in I<keydata1> and I<keydata2> match. It is assumed that
294 the caller has ensured that I<keydata1> and I<keydata2> are both owned
295 by the implementation of this function.
297 =head2 Key Object Import, Export and Copy Functions
299 OSSL_FUNC_keymgmt_import() should import data indicated by I<selection> into
300 I<keydata> with values taken from the B<OSSL_PARAM> array I<params>.
302 OSSL_FUNC_keymgmt_export() should extract values indicated by I<selection>
303 from I<keydata>, create an B<OSSL_PARAM> array with them and call
304 I<param_cb> with that array as well as the given I<cbarg>.
306 OSSL_FUNC_keymgmt_import_types() should return a constant array of descriptor
307 B<OSSL_PARAM> for data indicated by I<selection>, for parameters that
308 OSSL_FUNC_keymgmt_import() can handle.
310 OSSL_FUNC_keymgmt_export_types() should return a constant array of descriptor
311 B<OSSL_PARAM> for data indicated by I<selection>, that the
312 OSSL_FUNC_keymgmt_export() callback can expect to receive.
314 OSSL_FUNC_keymgmt_copy() should copy data subsets indicated by I<selection>
315 from I<keydata_from> to I<keydata_to>. It is assumed that the caller
316 has ensured that I<keydata_to> and I<keydata_from> are both owned by
317 the implementation of this function.
319 =head2 Common Information Parameters
321 See L<OSSL_PARAM(3)> for further details on the parameters structure.
323 Common information parameters currently recognised by all built-in
324 keymgmt algorithms are as follows:
328 =item "bits" (B<OSSL_PKEY_PARAM_BITS>) <integer>
330 The value should be the cryptographic length of the cryptosystem to
331 which the key belongs, in bits. The definition of cryptographic
332 length is specific to the key cryptosystem.
334 =item "max-size" (B<OSSL_PKEY_PARAM_MAX_SIZE>) <integer>
336 The value should be the maximum size that a caller should allocate to
337 safely store a signature (called I<sig> in L<provider-signature(7)>),
338 the result of asymmmetric encryption / decryption (I<out> in
339 L<provider-asym_cipher(7)>, a derived secret (I<secret> in
340 L<provider-keyexch(7)>, and similar data).
342 Because an EVP_KEYMGMT method is always tightly bound to another method
343 (signature, asymmetric cipher, key exchange, ...) and must be of the
344 same provider, this number only needs to be synchronised with the
345 dimensions handled in the rest of the same provider.
347 =item "security-bits" (B<OSSL_PKEY_PARAM_SECURITY_BITS>) <integer>
349 The value should be the number of security bits of the given key.
350 Bits of security is defined in SP800-57.
356 OSSL_FUNC_keymgmt_new() should return a valid reference to the newly created provider
357 side key object, or NULL on failure.
359 OSSL_FUNC_keymgmt_import(), OSSL_FUNC_keymgmt_export(), OSSL_FUNC_keymgmt_get_params() and
360 OSSL_FUNC_keymgmt_set_params() should return 1 for success or 0 on error.
362 OSSL_FUNC_keymgmt_validate() should return 1 on successful validation, or 0 on
365 OSSL_FUNC_keymgmt_has() should return 1 if all the selected data subsets are contained
366 in the given I<keydata> or 0 otherwise.
368 OSSL_FUNC_keymgmt_query_operation_name() should return a pointer to a string matching
369 the requested operation, or NULL if the same name used to fetch the keymgmt
372 OSSL_FUNC_keymgmt_gettable_params() and OSSL_FUNC_keymgmt_settable_params()
373 OSSL_FUNC_keymgmt_import_types(), OSSL_FUNC_keymgmt_export_types()
375 always return a constant B<OSSL_PARAM> array.
380 L<EVP_PKEY-X25519(7)>, L<EVP_PKEY-X448(7)>, L<EVP_PKEY-ED25519(7)>,
381 L<EVP_PKEY-ED448(7)>, L<EVP_PKEY-EC(7)>, L<EVP_PKEY-RSA(7)>,
382 L<EVP_PKEY-DSA(7)>, L<EVP_PKEY-DH(7)>
386 The KEYMGMT interface was introduced in OpenSSL 3.0.
390 Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
392 Licensed under the Apache License 2.0 (the "License"). You may not use
393 this file except in compliance with the License. You can obtain a copy
394 in the file LICENSE in the source distribution or at
395 L<https://www.openssl.org/source/license.html>.