1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
|
=pod
=head1 NAME
provider-keymgmt - The KEYMGMT library E<lt>-E<gt> provider functions
=head1 SYNOPSIS
#include <openssl/core_numbers.h>
/*
* None of these are actual functions, but are displayed like this for
* the function signatures for functions that are offered as function
* pointers in OSSL_DISPATCH arrays.
*/
/* Key object (keydata) creation and destruction */
void *OP_keymgmt_new(void *provctx);
void OP_keymgmt_free(void *keydata);
void *OP_keymgmt_gen_init(void *provctx, int selection);
int OP_keymgmt_gen_set_template(void *genctx, void *template);
int OP_keymgmt_gen_set_params(void *genctx, const OSSL_PARAM params[]);
const OSSL_PARAM *OP_keymgmt_gen_settable_params(void *provctx);
void *OP_keymgmt_gen(void *genctx, OSSL_CALLBACK *cb, void *cbarg);
void OP_keymgmt_gen_cleanup(void *genctx);
/* Key object information */
int OP_keymgmt_get_params(void *keydata, OSSL_PARAM params[]);
const OSSL_PARAM *OP_keymgmt_gettable_params(void);
int OP_keymgmt_set_params(void *keydata, const OSSL_PARAM params[]);
const OSSL_PARAM *OP_keymgmt_settable_params(void);
/* Key object content checks */
int OP_keymgmt_has(void *keydata, int selection);
int OP_keymgmt_match(const void *keydata1, const void *keydata2,
int selection);
/* Discovery of supported operations */
const char *OP_keymgmt_query_operation_name(int operation_id);
/* Key object import and export functions */
int OP_keymgmt_import(int selection, void *keydata, const OSSL_PARAM params[]);
const OSSL_PARAM *OP_keymgmt_import_types(int selection);
int OP_keymgmt_export(int selection, void *keydata,
OSSL_CALLBACK *param_cb, void *cbarg);
const OSSL_PARAM *OP_keymgmt_export_types(int selection);
/* Key object copy */
int OP_keymgmt_copy(void *keydata_to, const void *keydata_from, int selection);
/* Key object validation */
int OP_keymgmt_validate(void *keydata, int selection);
=head1 DESCRIPTION
The KEYMGMT operation doesn't have much public visibility in OpenSSL
libraries, it's rather an internal operation that's designed to work
in tandem with operations that use private/public key pairs.
Because the KEYMGMT operation shares knowledge with the operations it
works with in tandem, they must belong to the same provider.
The OpenSSL libraries will ensure that they do.
The primary responsibility of the KEYMGMT operation is to hold the
provider side key data for the OpenSSL library EVP_PKEY structure.
All "functions" mentioned here are passed as function pointers between
F<libcrypto> and the provider in B<OSSL_DISPATCH> arrays via
B<OSSL_ALGORITHM> arrays that are returned by the provider's
provider_query_operation() function
(see L<provider-base(7)/Provider Functions>).
All these "functions" have a corresponding function type definition
named B<OSSL_{name}_fn>, and a helper function to retrieve the
function pointer from a B<OSSL_DISPATCH> element named
B<OSSL_get_{name}>.
For example, the "function" OP_keymgmt_new() has these:
typedef void *(OSSL_OP_keymgmt_new_fn)(void *provctx);
static ossl_inline OSSL_OP_keymgmt_new_fn
OSSL_get_OP_keymgmt_new(const OSSL_DISPATCH *opf);
B<OSSL_DISPATCH> arrays are indexed by numbers that are provided as
macros in L<openssl-core_numbers.h(7)>, as follows:
OP_keymgmt_new OSSL_FUNC_KEYMGMT_NEW
OP_keymgmt_free OSSL_FUNC_KEYMGMT_FREE
OP_keymgmt_gen_init OSSL_FUNC_KEYMGMT_GEN_INIT
OP_keymgmt_gen_set_template OSSL_FUNC_KEYMGMT_GEN_SET_TEMPLATE
OP_keymgmt_gen_set_params OSSL_FUNC_KEYMGMT_GEN_SET_PARAMS
OP_keymgmt_gen_settable_params OSSL_FUNC_KEYMGMT_GEN_SETTABLE_PARAMS
OP_keymgmt_gen OSSL_FUNC_KEYMGMT_GEN
OP_keymgmt_gen_cleanup OSSL_FUNC_KEYMGMT_GEN_CLEANUP
OP_keymgmt_get_params OSSL_FUNC_KEYMGMT_GET_PARAMS
OP_keymgmt_gettable_params OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS
OP_keymgmt_set_params OSSL_FUNC_KEYMGMT_SET_PARAMS
OP_keymgmt_settable_params OSSL_FUNC_KEYMGMT_SETTABLE_PARAMS
OP_keymgmt_query_operation_name OSSL_FUNC_KEYMGMT_QUERY_OPERATION_NAME
OP_keymgmt_has OSSL_FUNC_KEYMGMT_HAS
OP_keymgmt_validate OSSL_FUNC_KEYMGMT_VALIDATE
OP_keymgmt_match OSSL_FUNC_KEYMGMT_MATCH
OP_keymgmt_import OSSL_FUNC_KEYMGMT_IMPORT
OP_keymgmt_import_types OSSL_FUNC_KEYMGMT_IMPORT_TYPES
OP_keymgmt_export OSSL_FUNC_KEYMGMT_EXPORT
OP_keymgmt_export_types OSSL_FUNC_KEYMGMT_EXPORT_TYPES
OP_keymgmt_copy OSSL_FUNC_KEYMGMT_COPY
=head2 Key Objects
A key object is a collection of data for an asymmetric key, and is
represented as I<keydata> in this manual.
The exact contents of a key object are defined by the provider, and it
is assumed that different operations in one and the same provider use
the exact same structure to represent this collection of data, so that
for example, a key object that has been created using the KEYMGMT
interface that we document here can be passed as is to other provider
operations, such as OP_signature_sign_init() (see
L<provider-signature(7)>).
With some of the KEYMGMT functions, it's possible to select a specific
subset of data to handle, governed by the bits in a I<selection>
indicator. The bits are:
=over 4
=item B<OSSL_KEYMGMT_SELECT_PRIVATE_KEY>
Indicating that the private key data in a key object should be
considered.
=item B<OSSL_KEYMGMT_SELECT_PUBLIC_KEY>
Indicating that the public key data in a key object should be
considered.
=item B<OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS>
Indicating that the domain parameters in a key object should be
considered.
=item B<OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS>
Indicating that other parameters in a key object should be
considered.
Other parameters are key parameters that don't fit any other
classification. In other words, this particular selector bit works as
a last resort bit bucket selector.
=back
Some selector bits have also been combined for easier use:
=over 4
=item B<OSSL_KEYMGMT_SELECT_ALL_PARAMETERS>
Indicating that all key object parameters should be considered,
regardless of their more granular classification.
=for comment This should used by EVP functions such as
EVP_PKEY_copy_parameters() and EVP_PKEY_cmp_parameters()
This is a combination of B<OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS> and
B<OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS>.
=for comment If more parameter categories are added, they should be
mentioned here too.
=item B<OSSL_KEYMGMT_SELECT_KEYPAIR>
Indicating that both the whole key pair in a key object should be
considered, i.e. the combination of public and private key.
This is a combination of B<OSSL_KEYMGMT_SELECT_PRIVATE_KEY> and
B<OSSL_KEYMGMT_SELECT_PUBLIC_KEY>.
=item B<OSSL_KEYMGMT_SELECT_ALL>
Indicating that everything in a key object should be considered.
=back
The exact interpretation of those bits or how they combine is left to
each function where you can specify a selector.
=for comment One might think that a combination of bits means that all
the selected data subsets must be considered, but then you have to
consider that when comparing key objects (future function), an
implementation might opt to not compare the private key if it has
compared the public key, since a match of one half implies a match of
the other half.
=head2 Constructing and Destructing Functions
OP_keymgmt_new() should create a provider side key object. The
provider context I<provctx> is passed and may be incorporated in the
key object, but that is not mandatory.
OP_keymgmt_free() should free the passed I<keydata>.
OP_keymgmt_gen_init(), OP_keymgmt_gen_set_template(),
OP_keymgmt_gen_set_params(), OP_keymgmt_gen_settable_params(),
OP_keymgmt_gen() and OP_keymgmt_gen_cleanup() work together as a more
elaborate context based key object constructor.
OP_keymgmt_gen_init() should create the key object generation context
and initialize it with I<selections>, which will determine what kind
of contents the key object to be generated should get.
OP_keymgmt_gen_set_template() should add I<template> to the context
I<genctx>. The I<template> is assumed to be a key object constructed
with the same KEYMGMT, and from which content that the implementation
chooses can be used as a template for the key object to be generated.
Typically, the generation of a DSA or DH key would get the domain
parameters from this I<template>.
OP_keymgmt_gen_set_params() should set additional parameters from
I<params> in the key object generation context I<genctx>.
OP_keymgmt_gen_settable_params() should return a constant array of
descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_gen_set_params()
can handle.
OP_keymgmt_gen() should perform the key object generation itself, and
return the result. The callback I<cb> should be called at regular
intervals with indications on how the key object generation
progresses.
OP_keymgmt_gen_cleanup() should clean up and free the key object
generation context I<genctx>
At least one of OP_keymgmt_new() and OP_keymgmt_gen() are mandatory,
as well as OP_keymgmt_free(). Additionally, if OP_keymgmt_gen() is
present, OP_keymgmt_gen_init() and OP_keymgmt_gen_cleanup() must be
present as well.
=head2 Key Object Information Functions
OP_keymgmt_get_params() should extract information data associated
with the given I<keydata>, see L</Information Parameters>.
OP_keymgmt_gettable_params() should return a constant array of
descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_get_params()
can handle.
If OP_keymgmt_gettable_params() is present, OP_keymgmt_get_params()
must also be present, and vice versa.
OP_keymgmt_set_params() should update information data associated
with the given I<keydata>, see L</Information Parameters>.
OP_keymgmt_settable_params() should return a constant array of
descriptor B<OSSL_PARAM>, for parameters that OP_keymgmt_set_params()
can handle.
If OP_keymgmt_settable_params() is present, OP_keymgmt_set_params()
must also be present, and vice versa.
=head2 Key Object Checking Functions
OP_keymgmt_query_operation_name() should return the name of the
supported algorithm for the operation I<operation_id>. This is
similar to provider_query_operation() (see L<provider-base(7)>),
but only works as an advisory. If this function is not present, or
returns NULL, the caller is free to assume that there's an algorithm
from the same provider, of the same name as the one used to fetch the
keymgmt and try to use that.
OP_keymgmt_has() should check whether the given I<keydata> contains the subsets
of data indicated by the I<selector>. A combination of several
selector bits must consider all those subsets, not just one. An
implementation is, however, free to consider an empty subset of data
to still be a valid subset.
OP_keymgmt_validate() should check if the I<keydata> contains valid
data subsets indicated by I<selection>. Some combined selections of
data subsets may cause validation of the combined data.
For example, the combination of B<OSSL_KEYMGMT_SELECT_PRIVATE_KEY> and
B<OSSL_KEYMGMT_SELECT_PUBLIC_KEY> (or B<OSSL_KEYMGMT_SELECT_KEYPAIR>
for short) is expected to check that the pairwise consistency of
I<keydata> is valid.
OP_keymgmt_match() should check if the data subset indicated by
I<selection> in I<keydata1> and I<keydata2> match. It is assumed that
the caller has ensured that I<keydata1> and I<keydata2> are both owned
by the implementation of this function.
=head2 Key Object Import, Export and Copy Functions
OP_keymgmt_import() should import data indicated by I<selection> into
I<keydata> with values taken from the B<OSSL_PARAM> array I<params>.
OP_keymgmt_export() should extract values indicated by I<selection>
from I<keydata>, create an B<OSSL_PARAM> array with them and call
I<param_cb> with that array as well as the given I<cbarg>.
OP_keymgmt_import_types() should return a constant array of descriptor
B<OSSL_PARAM> for data indicated by I<selection>, for parameters that
OP_keymgmt_import() can handle.
OP_keymgmt_export_types() should return a constant array of descriptor
B<OSSL_PARAM> for data indicated by I<selection>, that the
OP_keymgmt_export() callback can expect to receive.
OP_keymgmt_copy() should copy data subsets indicated by I<selection>
from I<keydata_from> to I<keydata_to>. It is assumed that the caller
has ensured that I<keydata_to> and I<keydata_from> are both owned by
the implementation of this function.
=head2 Built-in RSA Import/Export Types
The following Import/Export types are available for the built-in RSA algorithm:
=over 4
=item "n" (B<OSSL_PKEY_PARAM_RSA_N>) <unsigned integer>
The RSA "n" value.
=item "e" (B<OSSL_PKEY_PARAM_RSA_E>) <unsigned integer>
The RSA "e" value.
=item "d" (B<OSSL_PKEY_PARAM_RSA_D>) <unsigned integer>
The RSA "d" value.
=item "rsa-factor" (B<OSSL_PKEY_PARAM_RSA_FACTOR>) <unsigned integer>
An RSA factor. In 2 prime RSA these are often known as "p" or "q". This value
may be repeated up to 10 times in a single key.
=item "rsa-exponent" (B<OSSL_PKEY_PARAM_RSA_EXPONENT>) <unsigned integer>
An RSA CRT (Chinese Remainder Theorem) exponent. This value may be repeated up
to 10 times in a single key.
=item "rsa-coefficient" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT>) <unsigned integer>
An RSA CRT (Chinese Remainder Theorem) coefficient. This value may be repeated
up to 9 times in a single key.
=back
=head2 Built-in DSA and Diffie-Hellman Import/Export Types
The following Import/Export types are available for the built-in DSA and
Diffie-Hellman algorithms:
=over 4
=item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <unsigned integer>
The public key value.
=item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <unsigned integer>
The private key value.
=item "p" (B<OSSL_PKEY_PARAM_FFC_P>) <unsigned integer>
A DSA or Diffie-Hellman "p" value.
=item "q" (B<OSSL_PKEY_PARAM_FFC_Q>) <unsigned integer>
A DSA or Diffie-Hellman "q" value.
=item "g" (B<OSSL_PKEY_PARAM_FFC_G>) <unsigned integer>
A DSA or Diffie-Hellman "g" value.
=back
=head2 Built-in X25519, X448, ED25519 and ED448 Import/Export Types
The following Import/Export types are available for the built-in X25519, X448,
ED25519 and X448 algorithms:
=over 4
=item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <octet string>
The public key value.
=item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <octet string>
The private key value.
=back
=head2 Built-in EC Import/Export Types
The following Import/Export types are available for the built-in EC algorithm:
=over 4
=item "curve-name" (B<OSSL_PKEY_PARAM_EC_NAME>) <utf8 string>
The EC curve name.
=item "use-cofactor-flag" (B<OSSL_PKEY_PARAM_USE_COFACTOR_ECDH>) <integer>
Enable Cofactor DH (ECC CDH) if this value is 1, otherwise it uses normal EC DH
if the value is zero. The cofactor variant multiplies the shared secret by the
EC curve's cofactor (note for some curves the cofactor is 1).
=item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <octet string>
The public key value in EC point format.
=item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <unsigned integer>
The private key value.
=back
=head2 Information Parameters
See L<OSSL_PARAM(3)> for further details on the parameters structure.
Parameters currently recognised by built-in keymgmt algorithms
are as follows.
Not all parameters are relevant to, or are understood by all keymgmt
algorithms:
=over 4
=item "bits" (B<OSSL_PKEY_PARAM_BITS>) <integer>
The value should be the cryptographic length of the cryptosystem to
which the key belongs, in bits. The definition of cryptographic
length is specific to the key cryptosystem.
=item "max-size" (B<OSSL_PKEY_PARAM_MAX_SIZE>) <integer>
The value should be the maximum size that a caller should allocate to
safely store a signature (called I<sig> in L<provider-signature(7)>),
the result of asymmmetric encryption / decryption (I<out> in
L<provider-asym_cipher(7)>, a derived secret (I<secret> in
L<provider-keyexch(7)>, and similar data).
Because an EVP_KEYMGMT method is always tightly bound to another method
(signature, asymmetric cipher, key exchange, ...) and must be of the
same provider, this number only needs to be synchronised with the
dimensions handled in the rest of the same provider.
=item "security-bits" (B<OSSL_PKEY_PARAM_SECURITY_BITS>) <integer>
The value should be the number of security bits of the given key.
Bits of security is defined in SP800-57.
=item "use-cofactor-flag" (B<OSSL_PKEY_PARAM_USE_COFACTOR_FLAG>,
B<OSSL_PKEY_PARAM_USE_COFACTOR_ECDH>) <integer>
The value should be either 1 or 0, to respectively enable or disable
use of the cofactor in operations using this key.
In the context of a key that can be used to perform an Elliptic Curve
Diffie-Hellman key exchange, this parameter can be used to mark a requirement
for using the Cofactor Diffie-Hellman (CDH) variant of the key exchange
algorithm.
See also L<provider-keyexch(7)> for the related
B<OSSL_EXCHANGE_PARAM_EC_ECDH_COFACTOR_MODE> parameter that can be set on a
per-operation basis.
=back
=head1 RETURN VALUES
OP_keymgmt_new() should return a valid reference to the newly created provider
side key object, or NULL on failure.
OP_keymgmt_import(), OP_keymgmt_export(), OP_keymgmt_get_params() and
OP_keymgmt_set_params() should return 1 for success or 0 on error.
OP_keymgmt_validate() should return 1 on successful validation, or 0 on
failure.
OP_keymgmt_has() should return 1 if all the selected data subsets are contained
in the given I<keydata> or 0 otherwise.
OP_keymgmt_query_operation_name() should return a pointer to a string matching
the requested operation, or NULL if the same name used to fetch the keymgmt
applies.
OP_keymgmt_gettable_params() and OP_keymgmt_settable_params()
OP_keymgmt_import_types(), OP_keymgmt_export_types()
should
always return a constant B<OSSL_PARAM> array.
=head1 SEE ALSO
L<provider(7)>
=head1 HISTORY
The KEYMGMT interface was introduced in OpenSSL 3.0.
=head1 COPYRIGHT
Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.
=cut
|