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 void *OP_keymgmt_gen(void *genctx, OSSL_CALLBACK *cb, void *cbarg);
26 void OP_keymgmt_gen_cleanup(void *genctx);
28 /* Key object information */
29 int OP_keymgmt_get_params(void *keydata, OSSL_PARAM params[]);
30 const OSSL_PARAM *OP_keymgmt_gettable_params(void);
31 int OP_keymgmt_set_params(void *keydata, const OSSL_PARAM params[]);
32 const OSSL_PARAM *OP_keymgmt_settable_params(void);
34 /* Key object content checks */
35 int OP_keymgmt_has(void *keydata, int selection);
36 int OP_keymgmt_match(const void *keydata1, const void *keydata2,
39 /* Discovery of supported operations */
40 const char *OP_keymgmt_query_operation_name(int operation_id);
42 /* Key object import and export functions */
43 int OP_keymgmt_import(int selection, void *keydata, const OSSL_PARAM params[]);
44 const OSSL_PARAM *OP_keymgmt_import_types(int selection);
45 int OP_keymgmt_export(int selection, void *keydata,
46 OSSL_CALLBACK *param_cb, void *cbarg);
47 const OSSL_PARAM *OP_keymgmt_export_types(int selection);
50 int OP_keymgmt_copy(void *keydata_to, const void *keydata_from, int selection);
52 /* Key object validation */
53 int OP_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" OP_keymgmt_new() has these:
80 typedef void *(OSSL_OP_keymgmt_new_fn)(void *provctx);
81 static ossl_inline OSSL_OP_keymgmt_new_fn
82 OSSL_get_OP_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_numbers.h(7)>, as follows:
87 OP_keymgmt_new OSSL_FUNC_KEYMGMT_NEW
88 OP_keymgmt_free OSSL_FUNC_KEYMGMT_FREE
90 OP_keymgmt_gen_init OSSL_FUNC_KEYMGMT_GEN_INIT
91 OP_keymgmt_gen_set_template OSSL_FUNC_KEYMGMT_GEN_SET_TEMPLATE
92 OP_keymgmt_gen_set_params OSSL_FUNC_KEYMGMT_GEN_SET_PARAMS
93 OP_keymgmt_gen_settable_params OSSL_FUNC_KEYMGMT_GEN_SETTABLE_PARAMS
94 OP_keymgmt_gen OSSL_FUNC_KEYMGMT_GEN
95 OP_keymgmt_gen_cleanup OSSL_FUNC_KEYMGMT_GEN_CLEANUP
97 OP_keymgmt_get_params OSSL_FUNC_KEYMGMT_GET_PARAMS
98 OP_keymgmt_gettable_params OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS
99 OP_keymgmt_set_params OSSL_FUNC_KEYMGMT_SET_PARAMS
100 OP_keymgmt_settable_params OSSL_FUNC_KEYMGMT_SETTABLE_PARAMS
102 OP_keymgmt_query_operation_name OSSL_FUNC_KEYMGMT_QUERY_OPERATION_NAME
104 OP_keymgmt_has OSSL_FUNC_KEYMGMT_HAS
105 OP_keymgmt_validate OSSL_FUNC_KEYMGMT_VALIDATE
106 OP_keymgmt_match OSSL_FUNC_KEYMGMT_MATCH
108 OP_keymgmt_import OSSL_FUNC_KEYMGMT_IMPORT
109 OP_keymgmt_import_types OSSL_FUNC_KEYMGMT_IMPORT_TYPES
110 OP_keymgmt_export OSSL_FUNC_KEYMGMT_EXPORT
111 OP_keymgmt_export_types OSSL_FUNC_KEYMGMT_EXPORT_TYPES
113 OP_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 OP_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 OP_keymgmt_free() should free the passed I<keydata>.
210 OP_keymgmt_gen_init(), OP_keymgmt_gen_set_template(),
211 OP_keymgmt_gen_set_params(), OP_keymgmt_gen_settable_params(),
212 OP_keymgmt_gen() and OP_keymgmt_gen_cleanup() work together as a more
213 elaborate context based key object constructor.
215 OP_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 OP_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 OP_keymgmt_gen_set_params() should set additional parameters from
227 I<params> in the key object generation context I<genctx>.
229 OP_keymgmt_gen_settable_params() should return a constant array of
230 descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_gen_set_params()
233 OP_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 OP_keymgmt_gen_cleanup() should clean up and free the key object
239 generation context I<genctx>
241 At least one of OP_keymgmt_new() and OP_keymgmt_gen() are mandatory,
242 as well as OP_keymgmt_free(). Additionally, if OP_keymgmt_gen() is
243 present, OP_keymgmt_gen_init() and OP_keymgmt_gen_cleanup() must be
246 =head2 Key Object Information Functions
248 OP_keymgmt_get_params() should extract information data associated
249 with the given I<keydata>, see L</Information Parameters>.
251 OP_keymgmt_gettable_params() should return a constant array of
252 descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_get_params()
255 If OP_keymgmt_gettable_params() is present, OP_keymgmt_get_params()
256 must also be present, and vice versa.
258 OP_keymgmt_set_params() should update information data associated
259 with the given I<keydata>, see L</Information Parameters>.
261 OP_keymgmt_settable_params() should return a constant array of
262 descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_set_params()
265 If OP_keymgmt_settable_params() is present, OP_keymgmt_set_params()
266 must also be present, and vice versa.
268 =head2 Key Object Checking Functions
270 OP_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 OP_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 OP_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 OP_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 OP_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 OP_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 OP_keymgmt_import_types() should return a constant array of descriptor
307 B<OSSL_PARAM> for data indicated by I<selection>, for parameters that
308 OP_keymgmt_import() can handle.
310 OP_keymgmt_export_types() should return a constant array of descriptor
311 B<OSSL_PARAM> for data indicated by I<selection>, that the
312 OP_keymgmt_export() callback can expect to receive.
314 OP_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 Built-in RSA Import/Export Types
321 The following Import/Export types are available for the built-in RSA algorithm:
325 =item "n" (B<OSSL_PKEY_PARAM_RSA_N>) <unsigned integer>
329 =item "e" (B<OSSL_PKEY_PARAM_RSA_E>) <unsigned integer>
333 =item "d" (B<OSSL_PKEY_PARAM_RSA_D>) <unsigned integer>
337 =item "rsa-factor1" (B<OSSL_PKEY_PARAM_RSA_FACTOR1>) <unsigned integer>
339 =item "rsa-factor2" (B<OSSL_PKEY_PARAM_RSA_FACTOR2>) <unsigned integer>
341 =item "rsa-factor3" (B<OSSL_PKEY_PARAM_RSA_FACTOR3>) <unsigned integer>
343 =item "rsa-factor4" (B<OSSL_PKEY_PARAM_RSA_FACTOR4>) <unsigned integer>
345 =item "rsa-factor5" (B<OSSL_PKEY_PARAM_RSA_FACTOR5>) <unsigned integer>
347 =item "rsa-factor6" (B<OSSL_PKEY_PARAM_RSA_FACTOR6>) <unsigned integer>
349 =item "rsa-factor7" (B<OSSL_PKEY_PARAM_RSA_FACTOR7>) <unsigned integer>
351 =item "rsa-factor8" (B<OSSL_PKEY_PARAM_RSA_FACTOR8>) <unsigned integer>
353 =item "rsa-factor9" (B<OSSL_PKEY_PARAM_RSA_FACTOR9>) <unsigned integer>
355 =item "rsa-factor10" (B<OSSL_PKEY_PARAM_RSA_FACTOR10>) <unsigned integer>
357 RSA prime factors. The factors are known as "p", "q" and "r_i" in RFC8017.
358 Up to eight additional "r_i" prime factors are supported.
360 =item "rsa-exponent1" (B<OSSL_PKEY_PARAM_RSA_EXPONENT1>) <unsigned integer>
362 =item "rsa-exponent2" (B<OSSL_PKEY_PARAM_RSA_EXPONENT2>) <unsigned integer>
364 =item "rsa-exponent3" (B<OSSL_PKEY_PARAM_RSA_EXPONENT3>) <unsigned integer>
366 =item "rsa-exponent4" (B<OSSL_PKEY_PARAM_RSA_EXPONENT4>) <unsigned integer>
368 =item "rsa-exponent5" (B<OSSL_PKEY_PARAM_RSA_EXPONENT5>) <unsigned integer>
370 =item "rsa-exponent6" (B<OSSL_PKEY_PARAM_RSA_EXPONENT6>) <unsigned integer>
372 =item "rsa-exponent7" (B<OSSL_PKEY_PARAM_RSA_EXPONENT7>) <unsigned integer>
374 =item "rsa-exponent8" (B<OSSL_PKEY_PARAM_RSA_EXPONENT8>) <unsigned integer>
376 =item "rsa-exponent9" (B<OSSL_PKEY_PARAM_RSA_EXPONENT9>) <unsigned integer>
378 =item "rsa-exponent10" (B<OSSL_PKEY_PARAM_RSA_EXPONENT10>) <unsigned integer>
380 RSA CRT (Chinese Remainder Theorem) exponents. The exponents are known
381 as "dP", "dQ" and "d_i in RFC8017".
382 Up to eight additional "d_i" exponents are supported.
384 =item "rsa-coefficient1" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT1>) <unsigned integer>
386 =item "rsa-coefficient2" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT2>) <unsigned integer>
388 =item "rsa-coefficient3" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT3>) <unsigned integer>
390 =item "rsa-coefficient4" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT4>) <unsigned integer>
392 =item "rsa-coefficient5" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT5>) <unsigned integer>
394 =item "rsa-coefficient6" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT6>) <unsigned integer>
396 =item "rsa-coefficient7" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT7>) <unsigned integer>
398 =item "rsa-coefficient8" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT8>) <unsigned integer>
400 =item "rsa-coefficient9" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT9>) <unsigned integer>
402 RSA CRT (Chinese Remainder Theorem) coefficients. The coefficients are known as
404 Up to eight additional "t_i" exponents are supported.
408 =head2 Built-in DSA and Diffie-Hellman Import/Export Types
410 The following Import/Export types are available for the built-in DSA and
411 Diffie-Hellman algorithms:
415 =item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <unsigned integer>
417 The public key value.
419 =item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <unsigned integer>
421 The private key value.
423 =item "p" (B<OSSL_PKEY_PARAM_FFC_P>) <unsigned integer>
425 A DSA or Diffie-Hellman "p" value.
427 =item "q" (B<OSSL_PKEY_PARAM_FFC_Q>) <unsigned integer>
429 A DSA or Diffie-Hellman "q" value.
431 =item "g" (B<OSSL_PKEY_PARAM_FFC_G>) <unsigned integer>
433 A DSA or Diffie-Hellman "g" value.
437 =head2 Built-in X25519, X448, ED25519 and ED448 Import/Export Types
439 The following Import/Export types are available for the built-in X25519, X448,
440 ED25519 and X448 algorithms:
444 =item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <octet string>
446 The public key value.
448 =item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <octet string>
450 The private key value.
454 =head2 Built-in EC Import/Export Types
456 The following Import/Export types are available for the built-in EC algorithm:
460 =item "curve-name" (B<OSSL_PKEY_PARAM_EC_NAME>) <utf8 string>
464 =item "use-cofactor-flag" (B<OSSL_PKEY_PARAM_USE_COFACTOR_ECDH>) <integer>
466 Enable Cofactor DH (ECC CDH) if this value is 1, otherwise it uses normal EC DH
467 if the value is zero. The cofactor variant multiplies the shared secret by the
468 EC curve's cofactor (note for some curves the cofactor is 1).
470 =item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <octet string>
472 The public key value in EC point format.
474 =item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <unsigned integer>
476 The private key value.
480 =head2 Information Parameters
482 See L<OSSL_PARAM(3)> for further details on the parameters structure.
484 The Built-in Import/Export Types listed above are also Information Parameters.
485 Not all parameters are relevant to, or are understood by all keymgmt
488 Parameters currently recognised by built-in keymgmt algorithms
489 also include the following.
493 =item "bits" (B<OSSL_PKEY_PARAM_BITS>) <integer>
495 The value should be the cryptographic length of the cryptosystem to
496 which the key belongs, in bits. The definition of cryptographic
497 length is specific to the key cryptosystem.
499 =item "max-size" (B<OSSL_PKEY_PARAM_MAX_SIZE>) <integer>
501 The value should be the maximum size that a caller should allocate to
502 safely store a signature (called I<sig> in L<provider-signature(7)>),
503 the result of asymmmetric encryption / decryption (I<out> in
504 L<provider-asym_cipher(7)>, a derived secret (I<secret> in
505 L<provider-keyexch(7)>, and similar data).
507 Because an EVP_KEYMGMT method is always tightly bound to another method
508 (signature, asymmetric cipher, key exchange, ...) and must be of the
509 same provider, this number only needs to be synchronised with the
510 dimensions handled in the rest of the same provider.
512 =item "security-bits" (B<OSSL_PKEY_PARAM_SECURITY_BITS>) <integer>
514 The value should be the number of security bits of the given key.
515 Bits of security is defined in SP800-57.
517 =item "use-cofactor-flag" (B<OSSL_PKEY_PARAM_USE_COFACTOR_FLAG>,
518 B<OSSL_PKEY_PARAM_USE_COFACTOR_ECDH>) <integer>
520 The value should be either 1 or 0, to respectively enable or disable
521 use of the cofactor in operations using this key.
523 In the context of a key that can be used to perform an Elliptic Curve
524 Diffie-Hellman key exchange, this parameter can be used to mark a requirement
525 for using the Cofactor Diffie-Hellman (CDH) variant of the key exchange
528 See also L<provider-keyexch(7)> for the related
529 B<OSSL_EXCHANGE_PARAM_EC_ECDH_COFACTOR_MODE> parameter that can be set on a
536 OP_keymgmt_new() should return a valid reference to the newly created provider
537 side key object, or NULL on failure.
539 OP_keymgmt_import(), OP_keymgmt_export(), OP_keymgmt_get_params() and
540 OP_keymgmt_set_params() should return 1 for success or 0 on error.
542 OP_keymgmt_validate() should return 1 on successful validation, or 0 on
545 OP_keymgmt_has() should return 1 if all the selected data subsets are contained
546 in the given I<keydata> or 0 otherwise.
548 OP_keymgmt_query_operation_name() should return a pointer to a string matching
549 the requested operation, or NULL if the same name used to fetch the keymgmt
552 OP_keymgmt_gettable_params() and OP_keymgmt_settable_params()
553 OP_keymgmt_import_types(), OP_keymgmt_export_types()
555 always return a constant B<OSSL_PARAM> array.
563 The KEYMGMT interface was introduced in OpenSSL 3.0.
567 Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
569 Licensed under the Apache License 2.0 (the "License"). You may not use
570 this file except in compliance with the License. You can obtain a copy
571 in the file LICENSE in the source distribution or at
572 L<https://www.openssl.org/source/license.html>.