1PROVIDER-KEYMGMT(7ossl)             OpenSSL            PROVIDER-KEYMGMT(7ossl)
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NAME

6       provider-keymgmt - The KEYMGMT library <-> provider functions
7

SYNOPSIS

9        #include <openssl/core_dispatch.h>
10
11        /*
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.
15         */
16
17        /* Key object (keydata) creation and destruction */
18        void *OSSL_FUNC_keymgmt_new(void *provctx);
19        void OSSL_FUNC_keymgmt_free(void *keydata);
20
21        /* Generation, a more complex constructor */
22        void *OSSL_FUNC_keymgmt_gen_init(void *provctx, int selection,
23                                         const OSSL_PARAM params[]);
24        int OSSL_FUNC_keymgmt_gen_set_template(void *genctx, void *template);
25        int OSSL_FUNC_keymgmt_gen_set_params(void *genctx, const OSSL_PARAM params[]);
26        const OSSL_PARAM *OSSL_FUNC_keymgmt_gen_settable_params(void *genctx,
27                                                                void *provctx);
28        void *OSSL_FUNC_keymgmt_gen(void *genctx, OSSL_CALLBACK *cb, void *cbarg);
29        void OSSL_FUNC_keymgmt_gen_cleanup(void *genctx);
30
31        /* Key loading by object reference, also a constructor */
32        void *OSSL_FUNC_keymgmt_load(const void *reference, size_t *reference_sz);
33
34        /* Key object information */
35        int OSSL_FUNC_keymgmt_get_params(void *keydata, OSSL_PARAM params[]);
36        const OSSL_PARAM *OSSL_FUNC_keymgmt_gettable_params(void *provctx);
37        int OSSL_FUNC_keymgmt_set_params(void *keydata, const OSSL_PARAM params[]);
38        const OSSL_PARAM *OSSL_FUNC_keymgmt_settable_params(void *provctx);
39
40        /* Key object content checks */
41        int OSSL_FUNC_keymgmt_has(const void *keydata, int selection);
42        int OSSL_FUNC_keymgmt_match(const void *keydata1, const void *keydata2,
43                                    int selection);
44
45        /* Discovery of supported operations */
46        const char *OSSL_FUNC_keymgmt_query_operation_name(int operation_id);
47
48        /* Key object import and export functions */
49        int OSSL_FUNC_keymgmt_import(void *keydata, int selection, const OSSL_PARAM params[]);
50        const OSSL_PARAM *OSSL_FUNC_keymgmt_import_types(int selection);
51        int OSSL_FUNC_keymgmt_export(void *keydata, int selection,
52                                     OSSL_CALLBACK *param_cb, void *cbarg);
53        const OSSL_PARAM *OSSL_FUNC_keymgmt_export_types(int selection);
54
55        /* Key object duplication, a constructor */
56        void *OSSL_FUNC_keymgmt_dup(const void *keydata_from, int selection);
57
58        /* Key object validation */
59        int OSSL_FUNC_keymgmt_validate(const void *keydata, int selection, int checktype);
60

DESCRIPTION

62       The KEYMGMT operation doesn't have much public visibility in OpenSSL
63       libraries, it's rather an internal operation that's designed to work in
64       tandem with operations that use private/public key pairs.
65
66       Because the KEYMGMT operation shares knowledge with the operations it
67       works with in tandem, they must belong to the same provider.  The
68       OpenSSL libraries will ensure that they do.
69
70       The primary responsibility of the KEYMGMT operation is to hold the
71       provider side key data for the OpenSSL library EVP_PKEY structure.
72
73       All "functions" mentioned here are passed as function pointers between
74       libcrypto and the provider in OSSL_DISPATCH arrays via OSSL_ALGORITHM
75       arrays that are returned by the provider's provider_query_operation()
76       function (see "Provider Functions" in provider-base(7)).
77
78       All these "functions" have a corresponding function type definition
79       named OSSL_FUNC_{name}_fn, and a helper function to retrieve the
80       function pointer from a OSSL_DISPATCH element named OSSL_FUNC_{name}.
81       For example, the "function" OSSL_FUNC_keymgmt_new() has these:
82
83        typedef void *(OSSL_FUNC_keymgmt_new_fn)(void *provctx);
84        static ossl_inline OSSL_FUNC_keymgmt_new_fn
85            OSSL_FUNC_keymgmt_new(const OSSL_DISPATCH *opf);
86
87       OSSL_DISPATCH arrays are indexed by numbers that are provided as macros
88       in openssl-core_dispatch.h(7), as follows:
89
90        OSSL_FUNC_keymgmt_new                  OSSL_FUNC_KEYMGMT_NEW
91        OSSL_FUNC_keymgmt_free                 OSSL_FUNC_KEYMGMT_FREE
92
93        OSSL_FUNC_keymgmt_gen_init             OSSL_FUNC_KEYMGMT_GEN_INIT
94        OSSL_FUNC_keymgmt_gen_set_template     OSSL_FUNC_KEYMGMT_GEN_SET_TEMPLATE
95        OSSL_FUNC_keymgmt_gen_set_params       OSSL_FUNC_KEYMGMT_GEN_SET_PARAMS
96        OSSL_FUNC_keymgmt_gen_settable_params  OSSL_FUNC_KEYMGMT_GEN_SETTABLE_PARAMS
97        OSSL_FUNC_keymgmt_gen                  OSSL_FUNC_KEYMGMT_GEN
98        OSSL_FUNC_keymgmt_gen_cleanup          OSSL_FUNC_KEYMGMT_GEN_CLEANUP
99
100        OSSL_FUNC_keymgmt_load                 OSSL_FUNC_KEYMGMT_LOAD
101
102        OSSL_FUNC_keymgmt_get_params           OSSL_FUNC_KEYMGMT_GET_PARAMS
103        OSSL_FUNC_keymgmt_gettable_params      OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS
104        OSSL_FUNC_keymgmt_set_params           OSSL_FUNC_KEYMGMT_SET_PARAMS
105        OSSL_FUNC_keymgmt_settable_params      OSSL_FUNC_KEYMGMT_SETTABLE_PARAMS
106
107        OSSL_FUNC_keymgmt_query_operation_name OSSL_FUNC_KEYMGMT_QUERY_OPERATION_NAME
108
109        OSSL_FUNC_keymgmt_has                  OSSL_FUNC_KEYMGMT_HAS
110        OSSL_FUNC_keymgmt_validate             OSSL_FUNC_KEYMGMT_VALIDATE
111        OSSL_FUNC_keymgmt_match                OSSL_FUNC_KEYMGMT_MATCH
112
113        OSSL_FUNC_keymgmt_import               OSSL_FUNC_KEYMGMT_IMPORT
114        OSSL_FUNC_keymgmt_import_types         OSSL_FUNC_KEYMGMT_IMPORT_TYPES
115        OSSL_FUNC_keymgmt_export               OSSL_FUNC_KEYMGMT_EXPORT
116        OSSL_FUNC_keymgmt_export_types         OSSL_FUNC_KEYMGMT_EXPORT_TYPES
117
118        OSSL_FUNC_keymgmt_dup                  OSSL_FUNC_KEYMGMT_DUP
119
120   Key Objects
121       A key object is a collection of data for an asymmetric key, and is
122       represented as keydata in this manual.
123
124       The exact contents of a key object are defined by the provider, and it
125       is assumed that different operations in one and the same provider use
126       the exact same structure to represent this collection of data, so that
127       for example, a key object that has been created using the KEYMGMT
128       interface that we document here can be passed as is to other provider
129       operations, such as OP_signature_sign_init() (see
130       provider-signature(7)).
131
132       With some of the KEYMGMT functions, it's possible to select a specific
133       subset of data to handle, governed by the bits in a selection
134       indicator.  The bits are:
135
136       OSSL_KEYMGMT_SELECT_PRIVATE_KEY
137           Indicating that the private key data in a key object should be
138           considered.
139
140       OSSL_KEYMGMT_SELECT_PUBLIC_KEY
141           Indicating that the public key data in a key object should be
142           considered.
143
144       OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS
145           Indicating that the domain parameters in a key object should be
146           considered.
147
148       OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS
149           Indicating that other parameters in a key object should be
150           considered.
151
152           Other parameters are key parameters that don't fit any other
153           classification.  In other words, this particular selector bit works
154           as a last resort bit bucket selector.
155
156       Some selector bits have also been combined for easier use:
157
158       OSSL_KEYMGMT_SELECT_ALL_PARAMETERS
159           Indicating that all key object parameters should be considered,
160           regardless of their more granular classification.
161
162           This is a combination of OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS and
163           OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS.
164
165       OSSL_KEYMGMT_SELECT_KEYPAIR
166           Indicating that both the whole key pair in a key object should be
167           considered, i.e. the combination of public and private key.
168
169           This is a combination of OSSL_KEYMGMT_SELECT_PRIVATE_KEY and
170           OSSL_KEYMGMT_SELECT_PUBLIC_KEY.
171
172       OSSL_KEYMGMT_SELECT_ALL
173           Indicating that everything in a key object should be considered.
174
175       The exact interpretation of those bits or how they combine is left to
176       each function where you can specify a selector.
177
178       It's left to the provider implementation to decide what is reasonable
179       to do with regards to received selector bits and how to do it.  Among
180       others, an implementation of OSSL_FUNC_keymgmt_match() might opt to not
181       compare the private half if it has compared the public half, since a
182       match of one half implies a match of the other half.
183
184   Constructing and Destructing Functions
185       OSSL_FUNC_keymgmt_new() should create a provider side key object.  The
186       provider context provctx is passed and may be incorporated in the key
187       object, but that is not mandatory.
188
189       OSSL_FUNC_keymgmt_free() should free the passed keydata.
190
191       OSSL_FUNC_keymgmt_gen_init(), OSSL_FUNC_keymgmt_gen_set_template(),
192       OSSL_FUNC_keymgmt_gen_set_params(),
193       OSSL_FUNC_keymgmt_gen_settable_params(), OSSL_FUNC_keymgmt_gen() and
194       OSSL_FUNC_keymgmt_gen_cleanup() work together as a more elaborate
195       context based key object constructor.
196
197       OSSL_FUNC_keymgmt_gen_init() should create the key object generation
198       context and initialize it with selections, which will determine what
199       kind of contents the key object to be generated should get.  The
200       params, if not NULL, should be set on the context in a manner similar
201       to using OSSL_FUNC_keymgmt_set_params().
202
203       OSSL_FUNC_keymgmt_gen_set_template() should add template to the context
204       genctx.  The template is assumed to be a key object constructed with
205       the same KEYMGMT, and from which content that the implementation
206       chooses can be used as a template for the key object to be generated.
207       Typically, the generation of a DSA or DH key would get the domain
208       parameters from this template.
209
210       OSSL_FUNC_keymgmt_gen_set_params() should set additional parameters
211       from params in the key object generation context genctx.
212
213       OSSL_FUNC_keymgmt_gen_settable_params() should return a constant array
214       of descriptor OSSL_PARAM, for parameters that
215       OSSL_FUNC_keymgmt_gen_set_params() can handle.
216
217       OSSL_FUNC_keymgmt_gen() should perform the key object generation
218       itself, and return the result.  The callback cb should be called at
219       regular intervals with indications on how the key object generation
220       progresses.
221
222       OSSL_FUNC_keymgmt_gen_cleanup() should clean up and free the key object
223       generation context genctx
224
225       OSSL_FUNC_keymgmt_load() creates a provider side key object based on a
226       reference object with a size of reference_sz bytes, that only the
227       provider knows how to interpret, but that may come from other
228       operations.  Outside the provider, this reference is simply an array of
229       bytes.
230
231       At least one of OSSL_FUNC_keymgmt_new(), OSSL_FUNC_keymgmt_gen() and
232       OSSL_FUNC_keymgmt_load() are mandatory, as well as
233       OSSL_FUNC_keymgmt_free() and OSSL_FUNC_keymgmt_has(). Additionally, if
234       OSSL_FUNC_keymgmt_gen() is present, OSSL_FUNC_keymgmt_gen_init() and
235       OSSL_FUNC_keymgmt_gen_cleanup() must be present as well.
236
237   Key Object Information Functions
238       OSSL_FUNC_keymgmt_get_params() should extract information data
239       associated with the given keydata, see "Common Information Parameters".
240
241       OSSL_FUNC_keymgmt_gettable_params() should return a constant array of
242       descriptor OSSL_PARAM, for parameters that
243       OSSL_FUNC_keymgmt_get_params() can handle.
244
245       If OSSL_FUNC_keymgmt_gettable_params() is present,
246       OSSL_FUNC_keymgmt_get_params() must also be present, and vice versa.
247
248       OSSL_FUNC_keymgmt_set_params() should update information data
249       associated with the given keydata, see "Common Information Parameters".
250
251       OSSL_FUNC_keymgmt_settable_params() should return a constant array of
252       descriptor OSSL_PARAM, for parameters that
253       OSSL_FUNC_keymgmt_set_params() can handle.
254
255       If OSSL_FUNC_keymgmt_settable_params() is present,
256       OSSL_FUNC_keymgmt_set_params() must also be present, and vice versa.
257
258   Key Object Checking Functions
259       OSSL_FUNC_keymgmt_query_operation_name() should return the name of the
260       supported algorithm for the operation operation_id.  This is similar to
261       provider_query_operation() (see provider-base(7)), but only works as an
262       advisory.  If this function is not present, or returns NULL, the caller
263       is free to assume that there's an algorithm from the same provider, of
264       the same name as the one used to fetch the keymgmt and try to use that.
265
266       OSSL_FUNC_keymgmt_has() should check whether the given keydata contains
267       the subsets of data indicated by the selector.  A combination of
268       several selector bits must consider all those subsets, not just one.
269       An implementation is, however, free to consider an empty subset of data
270       to still be a valid subset. For algorithms where some selection is not
271       meaningful such as OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS for RSA keys
272       the function should just return 1 as the selected subset is not really
273       missing in the key.
274
275       OSSL_FUNC_keymgmt_validate() should check if the keydata contains valid
276       data subsets indicated by selection.  Some combined selections of data
277       subsets may cause validation of the combined data.  For example, the
278       combination of OSSL_KEYMGMT_SELECT_PRIVATE_KEY and
279       OSSL_KEYMGMT_SELECT_PUBLIC_KEY (or OSSL_KEYMGMT_SELECT_KEYPAIR for
280       short) is expected to check that the pairwise consistency of keydata is
281       valid. The checktype parameter controls what type of check is performed
282       on the subset of data. Two types of check are defined:
283       OSSL_KEYMGMT_VALIDATE_FULL_CHECK and OSSL_KEYMGMT_VALIDATE_QUICK_CHECK.
284       The interpretation of how much checking is performed in a full check
285       versus a quick check is key type specific. Some providers may have no
286       distinction between a full check and a quick check. For algorithms
287       where some selection is not meaningful such as
288       OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS for RSA keys the function should
289       just return 1 as there is nothing to validate for that selection.
290
291       OSSL_FUNC_keymgmt_match() should check if the data subset indicated by
292       selection in keydata1 and keydata2 match.  It is assumed that the
293       caller has ensured that keydata1 and keydata2 are both owned by the
294       implementation of this function.
295
296   Key Object Import, Export and Duplication Functions
297       OSSL_FUNC_keymgmt_import() should import data indicated by selection
298       into keydata with values taken from the OSSL_PARAM array params.
299
300       OSSL_FUNC_keymgmt_export() should extract values indicated by selection
301       from keydata, create an OSSL_PARAM array with them and call param_cb
302       with that array as well as the given cbarg.
303
304       OSSL_FUNC_keymgmt_import_types() should return a constant array of
305       descriptor OSSL_PARAM for data indicated by selection, for parameters
306       that OSSL_FUNC_keymgmt_import() can handle.
307
308       OSSL_FUNC_keymgmt_export_types() should return a constant array of
309       descriptor OSSL_PARAM for data indicated by selection, that the
310       OSSL_FUNC_keymgmt_export() callback can expect to receive.
311
312       OSSL_FUNC_keymgmt_dup() should duplicate data subsets indicated by
313       selection or the whole key data keydata_from and create a new provider
314       side key object with the data.
315
316   Common Information Parameters
317       See OSSL_PARAM(3) for further details on the parameters structure.
318
319       Common information parameters currently recognised by all built-in
320       keymgmt algorithms are as follows:
321
322       "bits" (OSSL_PKEY_PARAM_BITS) <integer>
323           The value should be the cryptographic length of the cryptosystem to
324           which the key belongs, in bits.  The definition of cryptographic
325           length is specific to the key cryptosystem.
326
327       "max-size" (OSSL_PKEY_PARAM_MAX_SIZE) <integer>
328           The value should be the maximum size that a caller should allocate
329           to safely store a signature (called sig in provider-signature(7)),
330           the result of asymmmetric encryption / decryption (out in
331           provider-asym_cipher(7), a derived secret (secret in
332           provider-keyexch(7), and similar data).
333
334           Because an EVP_KEYMGMT method is always tightly bound to another
335           method (signature, asymmetric cipher, key exchange, ...) and must
336           be of the same provider, this number only needs to be synchronised
337           with the dimensions handled in the rest of the same provider.
338
339       "security-bits" (OSSL_PKEY_PARAM_SECURITY_BITS) <integer>
340           The value should be the number of security bits of the given key.
341           Bits of security is defined in SP800-57.
342

RETURN VALUES

344       OSSL_FUNC_keymgmt_new() and OSSL_FUNC_keymgmt_dup() should return a
345       valid reference to the newly created provider side key object, or NULL
346       on failure.
347
348       OSSL_FUNC_keymgmt_import(), OSSL_FUNC_keymgmt_export(),
349       OSSL_FUNC_keymgmt_get_params() and OSSL_FUNC_keymgmt_set_params()
350       should return 1 for success or 0 on error.
351
352       OSSL_FUNC_keymgmt_validate() should return 1 on successful validation,
353       or 0 on failure.
354
355       OSSL_FUNC_keymgmt_has() should return 1 if all the selected data
356       subsets are contained in the given keydata or 0 otherwise.
357
358       OSSL_FUNC_keymgmt_query_operation_name() should return a pointer to a
359       string matching the requested operation, or NULL if the same name used
360       to fetch the keymgmt applies.
361
362       OSSL_FUNC_keymgmt_gettable_params() and
363       OSSL_FUNC_keymgmt_settable_params() OSSL_FUNC_keymgmt_import_types(),
364       OSSL_FUNC_keymgmt_export_types() should always return a constant
365       OSSL_PARAM array.
366

SEE ALSO

368       provider(7), EVP_PKEY-X25519(7), EVP_PKEY-X448(7), EVP_PKEY-ED25519(7),
369       EVP_PKEY-ED448(7), EVP_PKEY-EC(7), EVP_PKEY-RSA(7), EVP_PKEY-DSA(7),
370       EVP_PKEY-DH(7)
371

HISTORY

373       The KEYMGMT interface was introduced in OpenSSL 3.0.
374
376       Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.
377
378       Licensed under the Apache License 2.0 (the "License").  You may not use
379       this file except in compliance with the License.  You can obtain a copy
380       in the file LICENSE in the source distribution or at
381       <https://www.openssl.org/source/license.html>.
382
383
384
3853.0.5                             2022-11-01           PROVIDER-KEYMGMT(7ossl)
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