1=pod
2
3=head1 NAME
4
5EVP_KEYMGMT,
6EVP_KEYMGMT_fetch,
7EVP_KEYMGMT_up_ref,
8EVP_KEYMGMT_free,
9EVP_KEYMGMT_get0_provider,
10EVP_KEYMGMT_is_a,
11EVP_KEYMGMT_get0_description,
12EVP_KEYMGMT_get0_name,
13EVP_KEYMGMT_do_all_provided,
14EVP_KEYMGMT_names_do_all,
15EVP_KEYMGMT_gettable_params,
16EVP_KEYMGMT_settable_params,
17EVP_KEYMGMT_gen_settable_params
18- EVP key management routines
19
20=head1 SYNOPSIS
21
22 #include <openssl/evp.h>
23
24 typedef struct evp_keymgmt_st EVP_KEYMGMT;
25
26 EVP_KEYMGMT *EVP_KEYMGMT_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,
27                                const char *properties);
28 int EVP_KEYMGMT_up_ref(EVP_KEYMGMT *keymgmt);
29 void EVP_KEYMGMT_free(EVP_KEYMGMT *keymgmt);
30 const OSSL_PROVIDER *EVP_KEYMGMT_get0_provider(const EVP_KEYMGMT *keymgmt);
31 int EVP_KEYMGMT_is_a(const EVP_KEYMGMT *keymgmt, const char *name);
32 const char *EVP_KEYMGMT_get0_name(const EVP_KEYMGMT *keymgmt);
33 const char *EVP_KEYMGMT_get0_description(const EVP_KEYMGMT *keymgmt);
34
35 void EVP_KEYMGMT_do_all_provided(OSSL_LIB_CTX *libctx,
36                                  void (*fn)(EVP_KEYMGMT *keymgmt, void *arg),
37                                  void *arg);
38 int EVP_KEYMGMT_names_do_all(const EVP_KEYMGMT *keymgmt,
39                              void (*fn)(const char *name, void *data),
40                              void *data);
41 const OSSL_PARAM *EVP_KEYMGMT_gettable_params(const EVP_KEYMGMT *keymgmt);
42 const OSSL_PARAM *EVP_KEYMGMT_settable_params(const EVP_KEYMGMT *keymgmt);
43 const OSSL_PARAM *EVP_KEYMGMT_gen_settable_params(const EVP_KEYMGMT *keymgmt);
44
45=head1 DESCRIPTION
46
47B<EVP_KEYMGMT> is a method object that represents key management
48implementations for different cryptographic algorithms.
49This method object provides functionality to have providers import key
50material from the outside, as well as export key material to the
51outside.
52Most of the functionality can only be used internally and has no
53public interface, this object is simply passed into other functions
54when needed.
55
56EVP_KEYMGMT_fetch() looks for an algorithm within the provider that
57has been loaded into the B<OSSL_LIB_CTX> given by I<ctx>, having the
58name given by I<algorithm> and the properties given by I<properties>.
59
60EVP_KEYMGMT_up_ref() increments the reference count for the given
61B<EVP_KEYMGMT> I<keymgmt>.
62
63EVP_KEYMGMT_free() decrements the reference count for the given
64B<EVP_KEYMGMT> I<keymgmt>, and when the count reaches zero, frees it.
65
66EVP_KEYMGMT_get0_provider() returns the provider that has this particular
67implementation.
68
69EVP_KEYMGMT_is_a() checks if I<keymgmt> is an implementation of an
70algorithm that's identifiable with I<name>.
71
72EVP_KEYMGMT_get0_name() returns the algorithm name from the provided
73implementation for the given I<keymgmt>. Note that the I<keymgmt> may have
74multiple synonyms associated with it. In this case the first name from the
75algorithm definition is returned. Ownership of the returned string is
76retained by the I<keymgmt> object and should not be freed by the caller.
77
78EVP_KEYMGMT_names_do_all() traverses all names for the I<keymgmt>, and
79calls I<fn> with each name and I<data>.
80
81EVP_KEYMGMT_get0_description() returns a description of the I<keymgmt>, meant
82for display and human consumption.  The description is at the discretion
83of the I<keymgmt> implementation.
84
85EVP_KEYMGMT_do_all_provided() traverses all key keymgmt implementations by
86all activated providers in the library context I<libctx>, and for each
87of the implementations, calls I<fn> with the implementation method and
88I<data> as arguments.
89
90EVP_KEYMGMT_gettable_params() and EVP_KEYMGMT_settable_params() return a
91constant L<OSSL_PARAM(3)> array that describes the names and types of key
92parameters that can be retrieved or set.
93EVP_KEYMGMT_gettable_params() is used by L<EVP_PKEY_gettable_params(3)>.
94
95EVP_KEYMGMT_gen_settable_params() returns a constant L<OSSL_PARAM(3)> array that
96describes the names and types of key generation parameters that can be set via
97L<EVP_PKEY_CTX_set_params(3)>.
98
99=head1 NOTES
100
101EVP_KEYMGMT_fetch() may be called implicitly by other fetching
102functions, using the same library context and properties.
103Any other API that uses keys will typically do this.
104
105=head1 RETURN VALUES
106
107EVP_KEYMGMT_fetch() returns a pointer to the key management
108implementation represented by an EVP_KEYMGMT object, or NULL on
109error.
110
111EVP_KEYMGMT_up_ref() returns 1 on success, or 0 on error.
112
113EVP_KEYMGMT_names_do_all() returns 1 if the callback was called for all
114names. A return value of 0 means that the callback was not called for any names.
115
116EVP_KEYMGMT_free() doesn't return any value.
117
118EVP_KEYMGMT_get0_provider() returns a pointer to a provider object, or NULL
119on error.
120
121EVP_KEYMGMT_is_a() returns 1 of I<keymgmt> was identifiable,
122otherwise 0.
123
124EVP_KEYMGMT_get0_name() returns the algorithm name, or NULL on error.
125
126EVP_KEYMGMT_get0_description() returns a pointer to a description, or NULL if
127there isn't one.
128
129EVP_KEYMGMT_gettable_params(), EVP_KEYMGMT_settable_params() and
130EVP_KEYMGMT_gen_settable_params() return a constant L<OSSL_PARAM(3)> array or
131NULL on error.
132
133=head1 SEE ALSO
134
135L<EVP_MD_fetch(3)>, L<OSSL_LIB_CTX(3)>
136
137=head1 HISTORY
138
139The functions described here were added in OpenSSL 3.0.
140
141=head1 COPYRIGHT
142
143Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
144
145Licensed under the Apache License 2.0 (the "License").  You may not use
146this file except in compliance with the License.  You can obtain a copy
147in the file LICENSE in the source distribution or at
148L<https://www.openssl.org/source/license.html>.
149
150=cut
151