xref: /freebsd/crypto/openssl/doc/man3/EVP_PKEY_new.pod (revision 0957b409a90fd597c1e9124cbaf3edd2b488f4ac)
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 number of bytes written is populated in B<*len>. If the
76buffer B<priv> is NULL then B<*len> is populated with the number of bytes
77required to hold the key. The calling application is responsible for ensuring
78that the buffer is large enough to receive the private key data. This function
79only works for algorithms that support raw private keys. Currently this is:
80B<EVP_PKEY_HMAC>, B<EVP_PKEY_POLY1305>, B<EVP_PKEY_SIPHASH>, B<EVP_PKEY_X25519>,
81B<EVP_PKEY_ED25519>, B<EVP_PKEY_X448> or B<EVP_PKEY_ED448>.
82
83EVP_PKEY_get_raw_public_key() fills the buffer provided by B<pub> with raw
84public key data. The number of bytes written is populated in B<*len>. If the
85buffer B<pub> is NULL then B<*len> is populated with the number of bytes
86required to hold the key. The calling application is responsible for ensuring
87that the buffer is large enough to receive the public key data. This function
88only works for algorithms that support raw public  keys. Currently this is:
89B<EVP_PKEY_X25519>, B<EVP_PKEY_ED25519>, B<EVP_PKEY_X448> or B<EVP_PKEY_ED448>.
90
91=head1 NOTES
92
93The B<EVP_PKEY> structure is used by various OpenSSL functions which require a
94general private key without reference to any particular algorithm.
95
96The structure returned by EVP_PKEY_new() is empty. To add a private or public
97key to this empty structure use the appropriate functions described in
98L<EVP_PKEY_set1_RSA(3)>, L<EVP_PKEY_set1_DSA>, L<EVP_PKEY_set1_DH> or
99L<EVP_PKEY_set1_EC_KEY>.
100
101=head1 RETURN VALUES
102
103EVP_PKEY_new(), EVP_PKEY_new_raw_private_key(), EVP_PKEY_new_raw_public_key(),
104EVP_PKEY_new_CMAC_key() and EVP_PKEY_new_mac_key() return either the newly
105allocated B<EVP_PKEY> structure or B<NULL> if an error occurred.
106
107EVP_PKEY_up_ref(), EVP_PKEY_get_raw_private_key() and
108EVP_PKEY_get_raw_public_key() return 1 for success and 0 for failure.
109
110=head1 SEE ALSO
111
112L<EVP_PKEY_set1_RSA(3)>, L<EVP_PKEY_set1_DSA>, L<EVP_PKEY_set1_DH> or
113L<EVP_PKEY_set1_EC_KEY>
114
115=head1 HISTORY
116
117EVP_PKEY_new() and EVP_PKEY_free() exist in all versions of OpenSSL.
118
119EVP_PKEY_up_ref() was first added to OpenSSL 1.1.0.
120EVP_PKEY_new_raw_private_key(), EVP_PKEY_new_raw_public_key(),
121EVP_PKEY_new_CMAC_key(), EVP_PKEY_new_raw_private_key() and
122EVP_PKEY_get_raw_public_key() were first added to OpenSSL 1.1.1.
123
124=head1 COPYRIGHT
125
126Copyright 2002-2018 The OpenSSL Project Authors. All Rights Reserved.
127
128Licensed under the OpenSSL license (the "License").  You may not use
129this file except in compliance with the License.  You can obtain a copy
130in the file LICENSE in the source distribution or at
131L<https://www.openssl.org/source/license.html>.
132
133=cut
134