5 provider-keymgmt - The KEYMGMT library E<lt>-E<gt> provider functions
9 #include <openssl/core_numbers.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 *OP_keymgmt_new(void *provctx);
19 void OP_keymgmt_free(void *keydata);
21 void *OP_keymgmt_gen_init(void *provctx, int selection);
22 int OP_keymgmt_gen_set_template(void *genctx, void *template);
23 int OP_keymgmt_gen_set_params(void *genctx, const OSSL_PARAM params[]);
24 const OSSL_PARAM *OP_keymgmt_gen_settable_params(void *provctx);
25 int OP_keymgmt_gen_get_params(void *genctx, const OSSL_PARAM params[]);
26 const OSSL_PARAM *OP_keymgmt_gen_gettable_params(void *provctx);
27 void *OP_keymgmt_gen(void *genctx, OSSL_CALLBACK *cb, void *cbarg);
28 void OP_keymgmt_gen_cleanup(void *genctx);
30 /* Key object information */
31 int OP_keymgmt_get_params(void *keydata, OSSL_PARAM params[]);
32 const OSSL_PARAM *OP_keymgmt_gettable_params(void);
33 int OP_keymgmt_set_params(void *keydata, const OSSL_PARAM params[]);
34 const OSSL_PARAM *OP_keymgmt_settable_params(void);
36 /* Key object content checks */
37 int OP_keymgmt_has(void *keydata, int selection);
38 int OP_keymgmt_match(const void *keydata1, const void *keydata2,
41 /* Discovery of supported operations */
42 const char *OP_keymgmt_query_operation_name(int operation_id);
44 /* Key object import and export functions */
45 int OP_keymgmt_import(int selection, void *keydata, const OSSL_PARAM params[]);
46 const OSSL_PARAM *OP_keymgmt_import_types(int selection);
47 int OP_keymgmt_export(int selection, void *keydata,
48 OSSL_CALLBACK *param_cb, void *cbarg);
49 const OSSL_PARAM *OP_keymgmt_export_types(int selection);
52 int OP_keymgmt_copy(void *keydata_to, const void *keydata_from, int selection);
54 /* Key object validation */
55 int OP_keymgmt_validate(void *keydata, int selection);
59 The KEYMGMT operation doesn't have much public visibility in OpenSSL
60 libraries, it's rather an internal operation that's designed to work
61 in tandem with operations that use private/public key pairs.
63 Because the KEYMGMT operation shares knowledge with the operations it
64 works with in tandem, they must belong to the same provider.
65 The OpenSSL libraries will ensure that they do.
67 The primary responsibility of the KEYMGMT operation is to hold the
68 provider side key data for the OpenSSL library EVP_PKEY structure.
70 All "functions" mentioned here are passed as function pointers between
71 F<libcrypto> and the provider in B<OSSL_DISPATCH> arrays via
72 B<OSSL_ALGORITHM> arrays that are returned by the provider's
73 provider_query_operation() function
74 (see L<provider-base(7)/Provider Functions>).
76 All these "functions" have a corresponding function type definition
77 named B<OSSL_{name}_fn>, and a helper function to retrieve the
78 function pointer from a B<OSSL_DISPATCH> element named
80 For example, the "function" OP_keymgmt_new() has these:
82 typedef void *(OSSL_OP_keymgmt_new_fn)(void *provctx);
83 static ossl_inline OSSL_OP_keymgmt_new_fn
84 OSSL_get_OP_keymgmt_new(const OSSL_DISPATCH *opf);
86 B<OSSL_DISPATCH> arrays are indexed by numbers that are provided as
87 macros in L<openssl-core_numbers.h(7)>, as follows:
89 OP_keymgmt_new OSSL_FUNC_KEYMGMT_NEW
90 OP_keymgmt_free OSSL_FUNC_KEYMGMT_FREE
92 OP_keymgmt_gen_init OSSL_FUNC_KEYMGMT_GEN_INIT
93 OP_keymgmt_gen_set_template OSSL_FUNC_KEYMGMT_GEN_SET_TEMPLATE
94 OP_keymgmt_gen_set_params OSSL_FUNC_KEYMGMT_GEN_SET_PARAMS
95 OP_keymgmt_gen_settable_params OSSL_FUNC_KEYMGMT_GEN_SETTABLE_PARAMS
96 OP_keymgmt_gen_get_params OSSL_FUNC_KEYMGMT_GEN_GET_PARAMS
97 OP_keymgmt_gen_gettable_params OSSL_FUNC_KEYMGMT_GEN_GETTABLE_PARAMS
98 OP_keymgmt_gen OSSL_FUNC_KEYMGMT_GEN
99 OP_keymgmt_gen_cleanup OSSL_FUNC_KEYMGMT_GEN_CLEANUP
101 OP_keymgmt_get_params OSSL_FUNC_KEYMGMT_GET_PARAMS
102 OP_keymgmt_gettable_params OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS
103 OP_keymgmt_set_params OSSL_FUNC_KEYMGMT_SET_PARAMS
104 OP_keymgmt_settable_params OSSL_FUNC_KEYMGMT_SETTABLE_PARAMS
106 OP_keymgmt_query_operation_name OSSL_FUNC_KEYMGMT_QUERY_OPERATION_NAME
108 OP_keymgmt_has OSSL_FUNC_KEYMGMT_HAS
109 OP_keymgmt_validate OSSL_FUNC_KEYMGMT_VALIDATE
110 OP_keymgmt_match OSSL_FUNC_KEYMGMT_MATCH
112 OP_keymgmt_import OSSL_FUNC_KEYMGMT_IMPORT
113 OP_keymgmt_import_types OSSL_FUNC_KEYMGMT_IMPORT_TYPES
114 OP_keymgmt_export OSSL_FUNC_KEYMGMT_EXPORT
115 OP_keymgmt_export_types OSSL_FUNC_KEYMGMT_EXPORT_TYPES
117 OP_keymgmt_copy OSSL_FUNC_KEYMGMT_COPY
121 A key object is a collection of data for an asymmetric key, and is
122 represented as I<keydata> in this manual.
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 L<provider-signature(7)>).
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 I<selection>
134 indicator. The bits are:
138 =item B<OSSL_KEYMGMT_SELECT_PRIVATE_KEY>
140 Indicating that the private key data in a key object should be
143 =item B<OSSL_KEYMGMT_SELECT_PUBLIC_KEY>
145 Indicating that the public key data in a key object should be
148 =item B<OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS>
150 Indicating that the domain parameters in a key object should be
153 =item B<OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS>
155 Indicating that other parameters in a key object should be
158 Other parameters are key parameters that don't fit any other
159 classification. In other words, this particular selector bit works as
160 a last resort bit bucket selector.
164 Some selector bits have also been combined for easier use:
168 =item B<OSSL_KEYMGMT_SELECT_ALL_PARAMETERS>
170 Indicating that all key object parameters should be considered,
171 regardless of their more granular classification.
173 =for comment This should used by EVP functions such as
174 EVP_PKEY_copy_parameters() and EVP_PKEY_cmp_parameters()
176 This is a combination of B<OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS> and
177 B<OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS>.
179 =for comment If more parameter categories are added, they should be
182 =item B<OSSL_KEYMGMT_SELECT_KEYPAIR>
184 Indicating that both the whole key pair in a key object should be
185 considered, i.e. the combination of public and private key.
187 This is a combination of B<OSSL_KEYMGMT_SELECT_PRIVATE_KEY> and
188 B<OSSL_KEYMGMT_SELECT_PUBLIC_KEY>.
190 =item B<OSSL_KEYMGMT_SELECT_ALL>
192 Indicating that everything in a key object should be considered.
196 The exact interpretation of those bits or how they combine is left to
197 each function where you can specify a selector.
199 =for comment One might think that a combination of bits means that all
200 the selected data subsets must be considered, but then you have to
201 consider that when comparing key objects (future function), an
202 implementation might opt to not compare the private key if it has
203 compared the public key, since a match of one half implies a match of
206 =head2 Constructing and Destructing Functions
208 OP_keymgmt_new() should create a provider side key object. The
209 provider context I<provctx> is passed and may be incorporated in the
210 key object, but that is not mandatory.
212 OP_keymgmt_free() should free the passed I<keydata>.
214 OP_keymgmt_gen_init(), OP_keymgmt_gen_set_template(),
215 OP_keymgmt_gen_set_params(), OP_keymgmt_gen_settable_params(),
216 OP_keymgmt_gen_get_params(), OP_keymgmt_gen_gettable_params(),
217 OP_keymgmt_gen() and OP_keymgmt_gen_cleanup() work together as a more
218 elaborate context based key object constructor.
220 OP_keymgmt_gen_init() should create the key object generation context
221 and initialize it with I<selections>, which will determine what kind
222 of contents the key object to be generated should get.
224 OP_keymgmt_gen_set_template() should add I<template> to the context
225 I<genctx>. The I<template> is assumed to be a key object constructed
226 with the same KEYMGMT, and from which content that the implementation
227 chooses can be used as a template for the key object to be generated.
228 Typically, the generation of a DSA or DH key would get the domain
229 parameters from this I<template>.
231 OP_keymgmt_gen_set_params() should set additional parameters from
232 I<params> in the key object generation context I<genctx>.
234 OP_keymgmt_gen_settable_params() should return a constant array of
235 descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_gen_set_params()
238 OP_keymgmt_gen_get_params() should extract information data associated
239 with the key object generation context I<genctx>.
241 OP_keymgmt_gen_gettable_params() should return a constant array of
242 descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_gen_get_params()
245 OP_keymgmt_gen() should perform the key object generation itself, and
246 return the result. The callback I<cb> should be called at regular
247 intervals with indications on how the key object generation
250 OP_keymgmt_gen_cleanup() should clean up and free the key object
251 generation context I<genctx>
253 At least one of OP_keymgmt_new() and OP_keymgmt_gen() are mandatory,
254 as well as OP_keymgmt_free(). Additionally, if OP_keymgmt_gen() is
255 present, OP_keymgmt_gen_init() and OP_keymgmt_gen_cleanup() must be
258 =head2 Key Object Information Functions
260 OP_keymgmt_get_params() should extract information data associated
261 with the given I<keydata>, see L</Information Parameters>.
263 OP_keymgmt_gettable_params() should return a constant array of
264 descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_get_params()
267 If OP_keymgmt_gettable_params() is present, OP_keymgmt_get_params()
268 must also be present, and vice versa.
270 OP_keymgmt_set_params() should update information data associated
271 with the given I<keydata>, see L</Information Parameters>.
273 OP_keymgmt_settable_params() should return a constant array of
274 descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_set_params()
277 If OP_keymgmt_settable_params() is present, OP_keymgmt_set_params()
278 must also be present, and vice versa.
280 =head2 Key Object Checking Functions
282 OP_keymgmt_query_operation_name() should return the name of the
283 supported algorithm for the operation I<operation_id>. This is
284 similar to provider_query_operation() (see L<provider-base(7)>),
285 but only works as an advisory. If this function is not present, or
286 returns NULL, the caller is free to assume that there's an algorithm
287 from the same provider, of the same name as the one used to fetch the
288 keymgmt and try to use that.
290 OP_keymgmt_has() should check whether the given I<keydata> contains the subsets
291 of data indicated by the I<selector>. A combination of several
292 selector bits must consider all those subsets, not just one. An
293 implementation is, however, free to consider an empty subset of data
294 to still be a valid subset.
296 OP_keymgmt_validate() should check if the I<keydata> contains valid
297 data subsets indicated by I<selection>. Some combined selections of
298 data subsets may cause validation of the combined data.
299 For example, the combination of B<OSSL_KEYMGMT_SELECT_PRIVATE_KEY> and
300 B<OSSL_KEYMGMT_SELECT_PUBLIC_KEY> (or B<OSSL_KEYMGMT_SELECT_KEYPAIR>
301 for short) is expected to check that the pairwise consistency of
304 OP_keymgmt_match() should check if the data subset indicated by
305 I<selection> in I<keydata1> and I<keydata2> match. It is assumed that
306 the caller has ensured that I<keydata1> and I<keydata2> are both owned
307 by the implementation of this function.
309 =head2 Key Object Import, Export and Copy Functions
311 OP_keymgmt_import() should import data indicated by I<selection> into
312 I<keydata> with values taken from the B<OSSL_PARAM> array I<params>.
314 OP_keymgmt_export() should extract values indicated by I<selection>
315 from I<keydata>, create an B<OSSL_PARAM> array with them and call
316 I<param_cb> with that array as well as the given I<cbarg>.
318 OP_keymgmt_import_types() should return a constant array of descriptor
319 B<OSSL_PARAM> for data indicated by I<selection>, for parameters that
320 OP_keymgmt_import() can handle.
322 OP_keymgmt_export_types() should return a constant array of descriptor
323 B<OSSL_PARAM> for data indicated by I<selection>, that the
324 OP_keymgmt_export() callback can expect to receive.
326 OP_keymgmt_copy() should copy data subsets indicated by I<selection>
327 from I<keydata_from> to I<keydata_to>. It is assumed that the caller
328 has ensured that I<keydata_to> and I<keydata_from> are both owned by
329 the implementation of this function.
331 =head2 Built-in RSA Import/Export Types
333 The following Import/Export types are available for the built-in RSA algorithm:
337 =item "n" (B<OSSL_PKEY_PARAM_RSA_N>) <unsigned integer>
341 =item "e" (B<OSSL_PKEY_PARAM_RSA_E>) <unsigned integer>
345 =item "d" (B<OSSL_PKEY_PARAM_RSA_D>) <unsigned integer>
349 =item "rsa-factor1" (B<OSSL_PKEY_PARAM_RSA_FACTOR1>) <unsigned integer>
351 =item "rsa-factor2" (B<OSSL_PKEY_PARAM_RSA_FACTOR2>) <unsigned integer>
353 =item "rsa-factor3" (B<OSSL_PKEY_PARAM_RSA_FACTOR3>) <unsigned integer>
355 =item "rsa-factor4" (B<OSSL_PKEY_PARAM_RSA_FACTOR4>) <unsigned integer>
357 =item "rsa-factor5" (B<OSSL_PKEY_PARAM_RSA_FACTOR5>) <unsigned integer>
359 =item "rsa-factor6" (B<OSSL_PKEY_PARAM_RSA_FACTOR6>) <unsigned integer>
361 =item "rsa-factor7" (B<OSSL_PKEY_PARAM_RSA_FACTOR7>) <unsigned integer>
363 =item "rsa-factor8" (B<OSSL_PKEY_PARAM_RSA_FACTOR8>) <unsigned integer>
365 =item "rsa-factor9" (B<OSSL_PKEY_PARAM_RSA_FACTOR9>) <unsigned integer>
367 =item "rsa-factor10" (B<OSSL_PKEY_PARAM_RSA_FACTOR10>) <unsigned integer>
369 RSA prime factors. The factors are known as "p", "q" and "r_i" in RFC8017.
370 Up to eight additional "r_i" prime factors are supported.
372 =item "rsa-exponent1" (B<OSSL_PKEY_PARAM_RSA_EXPONENT1>) <unsigned integer>
374 =item "rsa-exponent2" (B<OSSL_PKEY_PARAM_RSA_EXPONENT2>) <unsigned integer>
376 =item "rsa-exponent3" (B<OSSL_PKEY_PARAM_RSA_EXPONENT3>) <unsigned integer>
378 =item "rsa-exponent4" (B<OSSL_PKEY_PARAM_RSA_EXPONENT4>) <unsigned integer>
380 =item "rsa-exponent5" (B<OSSL_PKEY_PARAM_RSA_EXPONENT5>) <unsigned integer>
382 =item "rsa-exponent6" (B<OSSL_PKEY_PARAM_RSA_EXPONENT6>) <unsigned integer>
384 =item "rsa-exponent7" (B<OSSL_PKEY_PARAM_RSA_EXPONENT7>) <unsigned integer>
386 =item "rsa-exponent8" (B<OSSL_PKEY_PARAM_RSA_EXPONENT8>) <unsigned integer>
388 =item "rsa-exponent9" (B<OSSL_PKEY_PARAM_RSA_EXPONENT9>) <unsigned integer>
390 =item "rsa-exponent10" (B<OSSL_PKEY_PARAM_RSA_EXPONENT10>) <unsigned integer>
392 RSA CRT (Chinese Remainder Theorem) exponents. The exponents are known
393 as "dP", "dQ" and "d_i in RFC8017".
394 Up to eight additional "d_i" exponents are supported.
396 =item "rsa-coefficient1" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT1>) <unsigned integer>
398 =item "rsa-coefficient2" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT2>) <unsigned integer>
400 =item "rsa-coefficient3" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT3>) <unsigned integer>
402 =item "rsa-coefficient4" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT4>) <unsigned integer>
404 =item "rsa-coefficient5" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT5>) <unsigned integer>
406 =item "rsa-coefficient6" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT6>) <unsigned integer>
408 =item "rsa-coefficient7" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT7>) <unsigned integer>
410 =item "rsa-coefficient8" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT8>) <unsigned integer>
412 =item "rsa-coefficient9" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT9>) <unsigned integer>
414 RSA CRT (Chinese Remainder Theorem) coefficients. The coefficients are known as
416 Up to eight additional "t_i" exponents are supported.
420 =head2 Built-in DSA and Diffie-Hellman Import/Export Types
422 The following Import/Export types are available for the built-in DSA and
423 Diffie-Hellman algorithms:
427 =item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <unsigned integer>
429 The public key value.
431 =item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <unsigned integer>
433 The private key value.
435 =item "p" (B<OSSL_PKEY_PARAM_FFC_P>) <unsigned integer>
437 A DSA or Diffie-Hellman "p" value.
439 =item "q" (B<OSSL_PKEY_PARAM_FFC_Q>) <unsigned integer>
441 A DSA or Diffie-Hellman "q" value.
443 =item "g" (B<OSSL_PKEY_PARAM_FFC_G>) <unsigned integer>
445 A DSA or Diffie-Hellman "g" value.
449 =head2 Built-in X25519, X448, ED25519 and ED448 Import/Export Types
451 The following Import/Export types are available for the built-in X25519, X448,
452 ED25519 and X448 algorithms:
456 =item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <octet string>
458 The public key value.
460 =item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <octet string>
462 The private key value.
466 =head2 Built-in EC Import/Export Types
468 The following Import/Export types are available for the built-in EC algorithm:
472 =item "curve-name" (B<OSSL_PKEY_PARAM_EC_NAME>) <utf8 string>
476 =item "use-cofactor-flag" (B<OSSL_PKEY_PARAM_USE_COFACTOR_ECDH>) <integer>
478 Enable Cofactor DH (ECC CDH) if this value is 1, otherwise it uses normal EC DH
479 if the value is zero. The cofactor variant multiplies the shared secret by the
480 EC curve's cofactor (note for some curves the cofactor is 1).
482 =item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <octet string>
484 The public key value in EC point format.
486 =item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <unsigned integer>
488 The private key value.
492 =head2 Information Parameters
494 See L<OSSL_PARAM(3)> for further details on the parameters structure.
496 The Built-in Import/Export Types listed above are also Information Parameters.
497 Not all parameters are relevant to, or are understood by all keymgmt
500 Parameters currently recognised by built-in keymgmt algorithms
501 also include the following.
505 =item "bits" (B<OSSL_PKEY_PARAM_BITS>) <integer>
507 The value should be the cryptographic length of the cryptosystem to
508 which the key belongs, in bits. The definition of cryptographic
509 length is specific to the key cryptosystem.
511 =item "max-size" (B<OSSL_PKEY_PARAM_MAX_SIZE>) <integer>
513 The value should be the maximum size that a caller should allocate to
514 safely store a signature (called I<sig> in L<provider-signature(7)>),
515 the result of asymmmetric encryption / decryption (I<out> in
516 L<provider-asym_cipher(7)>, a derived secret (I<secret> in
517 L<provider-keyexch(7)>, and similar data).
519 Because an EVP_KEYMGMT method is always tightly bound to another method
520 (signature, asymmetric cipher, key exchange, ...) and must be of the
521 same provider, this number only needs to be synchronised with the
522 dimensions handled in the rest of the same provider.
524 =item "security-bits" (B<OSSL_PKEY_PARAM_SECURITY_BITS>) <integer>
526 The value should be the number of security bits of the given key.
527 Bits of security is defined in SP800-57.
529 =item "use-cofactor-flag" (B<OSSL_PKEY_PARAM_USE_COFACTOR_FLAG>,
530 B<OSSL_PKEY_PARAM_USE_COFACTOR_ECDH>) <integer>
532 The value should be either 1 or 0, to respectively enable or disable
533 use of the cofactor in operations using this key.
535 In the context of a key that can be used to perform an Elliptic Curve
536 Diffie-Hellman key exchange, this parameter can be used to mark a requirement
537 for using the Cofactor Diffie-Hellman (CDH) variant of the key exchange
540 See also L<provider-keyexch(7)> for the related
541 B<OSSL_EXCHANGE_PARAM_EC_ECDH_COFACTOR_MODE> parameter that can be set on a
548 OP_keymgmt_new() should return a valid reference to the newly created provider
549 side key object, or NULL on failure.
551 OP_keymgmt_import(), OP_keymgmt_export(), OP_keymgmt_get_params() and
552 OP_keymgmt_set_params() should return 1 for success or 0 on error.
554 OP_keymgmt_validate() should return 1 on successful validation, or 0 on
557 OP_keymgmt_has() should return 1 if all the selected data subsets are contained
558 in the given I<keydata> or 0 otherwise.
560 OP_keymgmt_query_operation_name() should return a pointer to a string matching
561 the requested operation, or NULL if the same name used to fetch the keymgmt
564 OP_keymgmt_gettable_params() and OP_keymgmt_settable_params()
565 OP_keymgmt_import_types(), OP_keymgmt_export_types()
567 always return a constant B<OSSL_PARAM> array.
575 The KEYMGMT interface was introduced in OpenSSL 3.0.
579 Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
581 Licensed under the Apache License 2.0 (the "License"). You may not use
582 this file except in compliance with the License. You can obtain a copy
583 in the file LICENSE in the source distribution or at
584 L<https://www.openssl.org/source/license.html>.