xref: /freebsd/crypto/openssl/doc/man3/X509_PUBKEY_new.pod (revision 66fd12cf4896eb08ad8e7a2627537f84ead84dd3)
1=pod
2
3=head1 NAME
4
5X509_PUBKEY_new_ex, X509_PUBKEY_new, X509_PUBKEY_free, X509_PUBKEY_dup,
6X509_PUBKEY_set, X509_PUBKEY_get0, X509_PUBKEY_get,
7d2i_PUBKEY_ex, d2i_PUBKEY, i2d_PUBKEY, d2i_PUBKEY_bio, d2i_PUBKEY_fp,
8i2d_PUBKEY_fp, i2d_PUBKEY_bio, X509_PUBKEY_set0_param, X509_PUBKEY_get0_param,
9X509_PUBKEY_eq - SubjectPublicKeyInfo public key functions
10
11=head1 SYNOPSIS
12
13 #include <openssl/x509.h>
14
15 X509_PUBKEY *X509_PUBKEY_new_ex(OSSL_LIB_CTX *libctx, const char *propq);
16 X509_PUBKEY *X509_PUBKEY_new(void);
17 void X509_PUBKEY_free(X509_PUBKEY *a);
18 X509_PUBKEY *X509_PUBKEY_dup(const X509_PUBKEY *a);
19
20 int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey);
21 EVP_PKEY *X509_PUBKEY_get0(const X509_PUBKEY *key);
22 EVP_PKEY *X509_PUBKEY_get(const X509_PUBKEY *key);
23
24 EVP_PKEY *d2i_PUBKEY_ex(EVP_PKEY **a, const unsigned char **pp, long length,
25                         OSSL_LIB_CTX *libctx, const char *propq);
26 EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length);
27 int i2d_PUBKEY(const EVP_PKEY *a, unsigned char **pp);
28
29 EVP_PKEY *d2i_PUBKEY_bio(BIO *bp, EVP_PKEY **a);
30 EVP_PKEY *d2i_PUBKEY_fp(FILE *fp, EVP_PKEY **a);
31
32 int i2d_PUBKEY_fp(const FILE *fp, EVP_PKEY *pkey);
33 int i2d_PUBKEY_bio(BIO *bp, const EVP_PKEY *pkey);
34
35 int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *aobj,
36                            int ptype, void *pval,
37                            unsigned char *penc, int penclen);
38 int X509_PUBKEY_get0_param(ASN1_OBJECT **ppkalg,
39                            const unsigned char **pk, int *ppklen,
40                            X509_ALGOR **pa, const X509_PUBKEY *pub);
41 int X509_PUBKEY_eq(X509_PUBKEY *a, X509_PUBKEY *b);
42
43=head1 DESCRIPTION
44
45The B<X509_PUBKEY> structure represents the ASN.1 B<SubjectPublicKeyInfo>
46structure defined in RFC5280 and used in certificates and certificate requests.
47
48X509_PUBKEY_new_ex() allocates and initializes an B<X509_PUBKEY> structure
49associated with the given B<OSSL_LIB_CTX> in the I<libctx> parameter. Any
50algorithm fetches associated with using the B<X509_PUBKEY> object will use
51the property query string I<propq>. See L<crypto(7)/ALGORITHM FETCHING> for
52further information about algorithm fetching.
53
54X509_PUBKEY_new() is the same as X509_PUBKEY_new_ex() except that the default
55(NULL) B<OSSL_LIB_CTX> and a NULL property query string are used.
56
57X509_PUBKEY_dup() creates a duplicate copy of the B<X509_PUBKEY> object
58specified by I<a>.
59
60X509_PUBKEY_free() frees up B<X509_PUBKEY> structure I<a>. If I<a> is NULL
61nothing is done.
62
63X509_PUBKEY_set() sets the public key in I<*x> to the public key contained
64in the B<EVP_PKEY> structure I<pkey>. If I<*x> is not NULL any existing
65public key structure will be freed.
66
67X509_PUBKEY_get0() returns the public key contained in I<key>. The returned
68value is an internal pointer which B<MUST NOT> be freed after use.
69
70X509_PUBKEY_get() is similar to X509_PUBKEY_get0() except the reference
71count on the returned key is incremented so it B<MUST> be freed using
72EVP_PKEY_free() after use.
73
74d2i_PUBKEY_ex() decodes an B<EVP_PKEY> structure using B<SubjectPublicKeyInfo>
75format.  Some public key decoding implementations may use cryptographic
76algorithms. In this case the supplied library context I<libctx> and property
77query string I<propq> are used.
78d2i_PUBKEY() does the same as d2i_PUBKEY_ex() except that the default
79library context and property query string are used.
80
81i2d_PUBKEY() encodes an B<EVP_PKEY> structure using B<SubjectPublicKeyInfo>
82format.
83
84d2i_PUBKEY_bio(), d2i_PUBKEY_fp(), i2d_PUBKEY_bio() and i2d_PUBKEY_fp() are
85similar to d2i_PUBKEY() and i2d_PUBKEY() except they decode or encode using a
86B<BIO> or B<FILE> pointer.
87
88X509_PUBKEY_set0_param() sets the public key parameters of I<pub>. The
89OID associated with the algorithm is set to I<aobj>. The type of the
90algorithm parameters is set to I<type> using the structure I<pval>.
91The encoding of the public key itself is set to the I<penclen>
92bytes contained in buffer I<penc>. On success ownership of all the supplied
93parameters is passed to I<pub> so they must not be freed after the
94call.
95
96X509_PUBKEY_get0_param() retrieves the public key parameters from I<pub>,
97I<*ppkalg> is set to the associated OID and the encoding consists of
98I<*ppklen> bytes at I<*pk>, I<*pa> is set to the associated
99AlgorithmIdentifier for the public key. If the value of any of these
100parameters is not required it can be set to NULL. All of the
101retrieved pointers are internal and must not be freed after the
102call.
103
104X509_PUBKEY_eq() compares two B<X509_PUBKEY> values.
105
106=head1 NOTES
107
108The B<X509_PUBKEY> functions can be used to encode and decode public keys
109in a standard format.
110
111In many cases applications will not call the B<X509_PUBKEY> functions
112directly: they will instead call wrapper functions such as X509_get0_pubkey().
113
114=head1 RETURN VALUES
115
116If the allocation fails, X509_PUBKEY_new() and X509_PUBKEY_dup() return
117NULL and set an error code that can be obtained by L<ERR_get_error(3)>.
118Otherwise they return a pointer to the newly allocated structure.
119
120X509_PUBKEY_free() does not return a value.
121
122X509_PUBKEY_get0() and X509_PUBKEY_get() return a pointer to an B<EVP_PKEY>
123structure or NULL if an error occurs.
124
125X509_PUBKEY_set(), X509_PUBKEY_set0_param() and X509_PUBKEY_get0_param()
126return 1 for success and 0 if an error occurred.
127
128X509_PUBKEY_eq() returns 1 for equal, 0 for different, and < 0 on error.
129
130=head1 SEE ALSO
131
132L<d2i_X509(3)>,
133L<ERR_get_error(3)>,
134L<X509_get_pubkey(3)>,
135
136=head1 HISTORY
137
138The X509_PUBKEY_new_ex() and X509_PUBKEY_eq() functions were added in OpenSSL
1393.0.
140
141=head1 COPYRIGHT
142
143Copyright 2016-2021 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