1=pod
2
3=head1 NAME
4
5EVP_PKEY_new,
6EVP_PKEY_up_ref,
7EVP_PKEY_free,
8EVP_PKEY_new_raw_private_key,
9EVP_PKEY_new_raw_public_key,
10EVP_PKEY_new_CMAC_key,
11EVP_PKEY_new_mac_key,
12EVP_PKEY_get_raw_private_key,
13EVP_PKEY_get_raw_public_key
14- public/private key allocation and raw key handling functions
15
16=head1 SYNOPSIS
17
18 #include <openssl/evp.h>
19
20 EVP_PKEY *EVP_PKEY_new(void);
21 int EVP_PKEY_up_ref(EVP_PKEY *key);
22 void EVP_PKEY_free(EVP_PKEY *key);
23
24 EVP_PKEY *EVP_PKEY_new_raw_private_key(int type, ENGINE *e,
25                                        const unsigned char *key, size_t keylen);
26 EVP_PKEY *EVP_PKEY_new_raw_public_key(int type, ENGINE *e,
27                                       const unsigned char *key, size_t keylen);
28 EVP_PKEY *EVP_PKEY_new_CMAC_key(ENGINE *e, const unsigned char *priv,
29                                 size_t len, const EVP_CIPHER *cipher);
30 EVP_PKEY *EVP_PKEY_new_mac_key(int type, ENGINE *e, const unsigned char *key,
31                                int keylen);
32
33 int EVP_PKEY_get_raw_private_key(const EVP_PKEY *pkey, unsigned char *priv,
34                                  size_t *len);
35 int EVP_PKEY_get_raw_public_key(const EVP_PKEY *pkey, unsigned char *pub,
36                                 size_t *len);
37
38=head1 DESCRIPTION
39
40The EVP_PKEY_new() function allocates an empty B<EVP_PKEY> structure which is
41used by OpenSSL to store public and private keys. The reference count is set to
42B<1>.
43
44EVP_PKEY_up_ref() increments the reference count of B<key>.
45
46EVP_PKEY_free() decrements the reference count of B<key> and, if the reference
47count is zero, frees it up. If B<key> is NULL, nothing is done.
48
49EVP_PKEY_new_raw_private_key() allocates a new B<EVP_PKEY>. If B<e> is non-NULL
50then the new B<EVP_PKEY> structure is associated with the engine B<e>. The
51B<type> argument indicates what kind of key this is. The value should be a NID
52for a public key algorithm that supports raw private keys, i.e. one of
53B<EVP_PKEY_HMAC>, B<EVP_PKEY_POLY1305>, B<EVP_PKEY_SIPHASH>, B<EVP_PKEY_X25519>,
54B<EVP_PKEY_ED25519>, B<EVP_PKEY_X448> or B<EVP_PKEY_ED448>. B<key> points to the
55raw private key data for this B<EVP_PKEY> which should be of length B<keylen>.
56The length should be appropriate for the type of the key. The public key data
57will be automatically derived from the given private key data (if appropriate
58for the algorithm type).
59
60EVP_PKEY_new_raw_public_key() works in the same way as
61EVP_PKEY_new_raw_private_key() except that B<key> points to the raw public key
62data. The B<EVP_PKEY> structure will be initialised without any private key
63information. Algorithm types that support raw public keys are
64B<EVP_PKEY_X25519>, B<EVP_PKEY_ED25519>, B<EVP_PKEY_X448> or B<EVP_PKEY_ED448>.
65
66EVP_PKEY_new_CMAC_key() works in the same way as EVP_PKEY_new_raw_private_key()
67except it is only for the B<EVP_PKEY_CMAC> algorithm type. In addition to the
68raw private key data, it also takes a cipher algorithm to be used during
69creation of a CMAC in the B<cipher> argument.
70
71EVP_PKEY_new_mac_key() works in the same way as EVP_PKEY_new_raw_private_key().
72New applications should use EVP_PKEY_new_raw_private_key() instead.
73
74EVP_PKEY_get_raw_private_key() fills the buffer provided by B<priv> with raw
75private key data. The size of the B<priv> buffer should be in B<*len> on entry
76to the function, and on exit B<*len> is updated with the number of bytes
77actually written. If the buffer B<priv> is NULL then B<*len> is populated with
78the number of bytes required to hold the key. The calling application is
79responsible for ensuring that the buffer is large enough to receive the private
80key data. This function only works for algorithms that support raw private keys.
81Currently this is: B<EVP_PKEY_HMAC>, B<EVP_PKEY_POLY1305>, B<EVP_PKEY_SIPHASH>,
82B<EVP_PKEY_X25519>, B<EVP_PKEY_ED25519>, B<EVP_PKEY_X448> or B<EVP_PKEY_ED448>.
83
84EVP_PKEY_get_raw_public_key() fills the buffer provided by B<pub> with raw
85public key data. The size of the B<pub> buffer should be in B<*len> on entry
86to the function, and on exit B<*len> is updated with the number of bytes
87actually written. If the buffer B<pub> is NULL then B<*len> is populated with
88the number of bytes required to hold the key. The calling application is
89responsible for ensuring that the buffer is large enough to receive the public
90key data. This function only works for algorithms that support raw public  keys.
91Currently this is: B<EVP_PKEY_X25519>, B<EVP_PKEY_ED25519>, B<EVP_PKEY_X448> or
92B<EVP_PKEY_ED448>.
93
94=head1 NOTES
95
96The B<EVP_PKEY> structure is used by various OpenSSL functions which require a
97general private key without reference to any particular algorithm.
98
99The structure returned by EVP_PKEY_new() is empty. To add a private or public
100key to this empty structure use the appropriate functions described in
101L<EVP_PKEY_set1_RSA(3)>, L<EVP_PKEY_set1_DSA>, L<EVP_PKEY_set1_DH> or
102L<EVP_PKEY_set1_EC_KEY>.
103
104=head1 RETURN VALUES
105
106EVP_PKEY_new(), EVP_PKEY_new_raw_private_key(), EVP_PKEY_new_raw_public_key(),
107EVP_PKEY_new_CMAC_key() and EVP_PKEY_new_mac_key() return either the newly
108allocated B<EVP_PKEY> structure or B<NULL> if an error occurred.
109
110EVP_PKEY_up_ref(), EVP_PKEY_get_raw_private_key() and
111EVP_PKEY_get_raw_public_key() return 1 for success and 0 for failure.
112
113=head1 SEE ALSO
114
115L<EVP_PKEY_set1_RSA(3)>, L<EVP_PKEY_set1_DSA>, L<EVP_PKEY_set1_DH> or
116L<EVP_PKEY_set1_EC_KEY>
117
118=head1 HISTORY
119
120The
121EVP_PKEY_new() and EVP_PKEY_free() functions exist in all versions of OpenSSL.
122
123The EVP_PKEY_up_ref() function was added in OpenSSL 1.1.0.
124
125The
126EVP_PKEY_new_raw_private_key(), EVP_PKEY_new_raw_public_key(),
127EVP_PKEY_new_CMAC_key(), EVP_PKEY_new_raw_private_key() and
128EVP_PKEY_get_raw_public_key() functions were added in OpenSSL 1.1.1.
129
130=head1 COPYRIGHT
131
132Copyright 2002-2020 The OpenSSL Project Authors. All Rights Reserved.
133
134Licensed under the OpenSSL license (the "License").  You may not use
135this file except in compliance with the License.  You can obtain a copy
136in the file LICENSE in the source distribution or at
137L<https://www.openssl.org/source/license.html>.
138
139=cut
140