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.
65If the argument is NULL, nothing is done.
66
67EVP_KEYMGMT_get0_provider() returns the provider that has this particular
68implementation.
69
70EVP_KEYMGMT_is_a() checks if I<keymgmt> is an implementation of an
71algorithm that's identifiable with I<name>.
72
73EVP_KEYMGMT_get0_name() returns the algorithm name from the provided
74implementation for the given I<keymgmt>. Note that the I<keymgmt> may have
75multiple synonyms associated with it. In this case the first name from the
76algorithm definition is returned. Ownership of the returned string is
77retained by the I<keymgmt> object and should not be freed by the caller.
78
79EVP_KEYMGMT_names_do_all() traverses all names for the I<keymgmt>, and
80calls I<fn> with each name and I<data>.
81
82EVP_KEYMGMT_get0_description() returns a description of the I<keymgmt>, meant
83for display and human consumption.  The description is at the discretion
84of the I<keymgmt> implementation.
85
86EVP_KEYMGMT_do_all_provided() traverses all key keymgmt implementations by
87all activated providers in the library context I<libctx>, and for each
88of the implementations, calls I<fn> with the implementation method and
89I<data> as arguments.
90
91EVP_KEYMGMT_gettable_params() and EVP_KEYMGMT_settable_params() return a
92constant L<OSSL_PARAM(3)> array that describes the names and types of key
93parameters that can be retrieved or set.
94EVP_KEYMGMT_gettable_params() is used by L<EVP_PKEY_gettable_params(3)>.
95
96EVP_KEYMGMT_gen_settable_params() returns a constant L<OSSL_PARAM(3)> array that
97describes the names and types of key generation parameters that can be set via
98L<EVP_PKEY_CTX_set_params(3)>.
99
100=head1 NOTES
101
102EVP_KEYMGMT_fetch() may be called implicitly by other fetching
103functions, using the same library context and properties.
104Any other API that uses keys will typically do this.
105
106=head1 RETURN VALUES
107
108EVP_KEYMGMT_fetch() returns a pointer to the key management
109implementation represented by an EVP_KEYMGMT object, or NULL on
110error.
111
112EVP_KEYMGMT_up_ref() returns 1 on success, or 0 on error.
113
114EVP_KEYMGMT_names_do_all() returns 1 if the callback was called for all
115names. A return value of 0 means that the callback was not called for any names.
116
117EVP_KEYMGMT_free() doesn't return any value.
118
119EVP_KEYMGMT_get0_provider() returns a pointer to a provider object, or NULL
120on error.
121
122EVP_KEYMGMT_is_a() returns 1 of I<keymgmt> was identifiable,
123otherwise 0.
124
125EVP_KEYMGMT_get0_name() returns the algorithm name, or NULL on error.
126
127EVP_KEYMGMT_get0_description() returns a pointer to a description, or NULL if
128there isn't one.
129
130EVP_KEYMGMT_gettable_params(), EVP_KEYMGMT_settable_params() and
131EVP_KEYMGMT_gen_settable_params() return a constant L<OSSL_PARAM(3)> array or
132NULL on error.
133
134=head1 SEE ALSO
135
136L<EVP_MD_fetch(3)>, L<OSSL_LIB_CTX(3)>
137
138=head1 HISTORY
139
140The functions described here were added in OpenSSL 3.0.
141
142=head1 COPYRIGHT
143
144Copyright 2019-2024 The OpenSSL Project Authors. All Rights Reserved.
145
146Licensed under the Apache License 2.0 (the "License").  You may not use
147this file except in compliance with the License.  You can obtain a copy
148in the file LICENSE in the source distribution or at
149L<https://www.openssl.org/source/license.html>.
150
151=cut
152