xref: /openssl/doc/man3/X509_PUBKEY_new.pod (revision 820723dd) 
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_ex_bio, d2i_PUBKEY_bio,
8d2i_PUBKEY_ex_fp, d2i_PUBKEY_fp, i2d_PUBKEY_fp, i2d_PUBKEY_bio,
9X509_PUBKEY_set0_public_key, X509_PUBKEY_set0_param, X509_PUBKEY_get0_param,
10X509_PUBKEY_eq - SubjectPublicKeyInfo public key functions
11
12=head1 SYNOPSIS
13
14 #include <openssl/x509.h>
15
16 X509_PUBKEY *X509_PUBKEY_new_ex(OSSL_LIB_CTX *libctx, const char *propq);
17 X509_PUBKEY *X509_PUBKEY_new(void);
18 void X509_PUBKEY_free(X509_PUBKEY *a);
19 X509_PUBKEY *X509_PUBKEY_dup(const X509_PUBKEY *a);
20
21 int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey);
22 EVP_PKEY *X509_PUBKEY_get0(const X509_PUBKEY *key);
23 EVP_PKEY *X509_PUBKEY_get(const X509_PUBKEY *key);
24
25 EVP_PKEY *d2i_PUBKEY_ex(EVP_PKEY **a, const unsigned char **pp, long length,
26                         OSSL_LIB_CTX *libctx, const char *propq);
27 EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length);
28 int i2d_PUBKEY(const EVP_PKEY *a, unsigned char **pp);
29
30 EVP_PKEY *d2i_PUBKEY_ex_bio(BIO *bp, EVP_PKEY **a, OSSL_LIB_CTX *libctx,
31                             const char *propq);
32 EVP_PKEY *d2i_PUBKEY_bio(BIO *bp, EVP_PKEY **a);
33
34 EVP_PKEY *d2i_PUBKEY_ex_fp(FILE *fp, EVP_PKEY **a, OSSL_LIB_CTX *libctx,
35                            const char *propq);
36 EVP_PKEY *d2i_PUBKEY_fp(FILE *fp, EVP_PKEY **a);
37
38 int i2d_PUBKEY_fp(const FILE *fp, EVP_PKEY *pkey);
39 int i2d_PUBKEY_bio(BIO *bp, const EVP_PKEY *pkey);
40
41 void X509_PUBKEY_set0_public_key(X509_PUBKEY *pub,
42                                  unsigned char *penc, int penclen);
43 int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *aobj,
44                            int ptype, void *pval,
45                            unsigned char *penc, int penclen);
46 int X509_PUBKEY_get0_param(ASN1_OBJECT **ppkalg,
47                            const unsigned char **pk, int *ppklen,
48                            X509_ALGOR **pa, const X509_PUBKEY *pub);
49 int X509_PUBKEY_eq(X509_PUBKEY *a, X509_PUBKEY *b);
50
51=head1 DESCRIPTION
52
53The B<X509_PUBKEY> structure represents the ASN.1 B<SubjectPublicKeyInfo>
54structure defined in RFC5280 and used in certificates and certificate requests.
55
56X509_PUBKEY_new_ex() allocates and initializes an B<X509_PUBKEY> structure
57associated with the given B<OSSL_LIB_CTX> in the I<libctx> parameter. Any
58algorithm fetches associated with using the B<X509_PUBKEY> object will use
59the property query string I<propq>. See L<crypto(7)/ALGORITHM FETCHING> for
60further information about algorithm fetching.
61
62X509_PUBKEY_new() is the same as X509_PUBKEY_new_ex() except that the default
63(NULL) B<OSSL_LIB_CTX> and a NULL property query string are used.
64
65X509_PUBKEY_dup() creates a duplicate copy of the B<X509_PUBKEY> object
66specified by I<a>.
67
68X509_PUBKEY_free() frees up B<X509_PUBKEY> structure I<a>. If I<a> is NULL
69nothing is done.
70
71X509_PUBKEY_set() sets the public key in I<*x> to the public key contained
72in the B<EVP_PKEY> structure I<pkey>. If I<*x> is not NULL any existing
73public key structure will be freed.
74
75X509_PUBKEY_get0() returns the public key contained in I<key>. The returned
76value is an internal pointer which B<MUST NOT> be freed after use.
77
78X509_PUBKEY_get() is similar to X509_PUBKEY_get0() except the reference
79count on the returned key is incremented so it B<MUST> be freed using
80EVP_PKEY_free() after use.
81
82d2i_PUBKEY_ex() decodes an B<EVP_PKEY> structure using B<SubjectPublicKeyInfo>
83format.  Some public key decoding implementations may use cryptographic
84algorithms. In this case the supplied library context I<libctx> and property
85query string I<propq> are used.
86d2i_PUBKEY() does the same as d2i_PUBKEY_ex() except that the default
87library context and property query string are used.
88
89i2d_PUBKEY() encodes an B<EVP_PKEY> structure using B<SubjectPublicKeyInfo>
90format.
91
92d2i_PUBKEY_bio(), d2i_PUBKEY_fp(), i2d_PUBKEY_bio() and i2d_PUBKEY_fp() are
93similar to d2i_PUBKEY() and i2d_PUBKEY() except they decode or encode using a
94B<BIO> or B<FILE> pointer.
95
96d2i_PUBKEY_ex_bio() and d2i_PUBKEY_ex_fp() are similar to d2i_PUBKEY_ex() except
97they decode using a B<BIO> or B<FILE> pointer.
98
99X509_PUBKEY_set0_public_key() sets the public-key encoding of I<pub>
100to the I<penclen> bytes contained in buffer I<penc>.
101Any earlier public-key encoding in I<pub> is freed.
102I<penc> may be NULL to indicate that there is no actual public key data.
103Ownership of the I<penc> argument is passed to I<pub>.
104
105X509_PUBKEY_set0_param() sets the public-key parameters of I<pub>.
106The OID associated with the algorithm is set to I<aobj>. The type of the
107algorithm parameters is set to I<type> using the structure I<pval>.
108If I<penc> is not NULL the encoding of the public key itself is set
109to the I<penclen> bytes contained in buffer I<penc> and
110any earlier public-key encoding in I<pub> is freed.
111On success ownership of all the supplied arguments is passed to I<pub>
112so they must not be freed after the call.
113
114X509_PUBKEY_get0_param() retrieves the public key parameters from I<pub>,
115I<*ppkalg> is set to the associated OID and the encoding consists of
116I<*ppklen> bytes at I<*pk>, I<*pa> is set to the associated
117AlgorithmIdentifier for the public key. If the value of any of these
118parameters is not required it can be set to NULL. All of the
119retrieved pointers are internal and must not be freed after the
120call.
121
122X509_PUBKEY_eq() compares two B<X509_PUBKEY> values.
123
124=head1 NOTES
125
126The B<X509_PUBKEY> functions can be used to encode and decode public keys
127in a standard format.
128
129In many cases applications will not call the B<X509_PUBKEY> functions
130directly: they will instead call wrapper functions such as X509_get0_pubkey().
131
132=head1 RETURN VALUES
133
134If the allocation fails, X509_PUBKEY_new() and X509_PUBKEY_dup() return
135NULL and set an error code that can be obtained by L<ERR_get_error(3)>.
136Otherwise they return a pointer to the newly allocated structure.
137
138X509_PUBKEY_free() does not return a value.
139
140X509_PUBKEY_get0(), X509_PUBKEY_get(), d2i_PUBKEY_ex(), d2i_PUBKEY(),
141d2i_PUBKEY_ex_bio(), d2i_PUBKEY_bio(), d2i_PUBKEY_ex_fp() and d2i_PUBKEY_fp()
142return a pointer to an B<EVP_PKEY> structure or NULL if an error occurs.
143
144i2d_PUBKEY() returns the number of bytes successfully encoded or a
145negative value if an error occurs.
146
147i2d_PUBKEY_fp() and i2d_PUBKEY_bio() return 1 if successfully
148encoded or 0 if an error occurs.
149
150X509_PUBKEY_set0_public_key() does not return a value.
151
152X509_PUBKEY_set(), X509_PUBKEY_set0_param() and X509_PUBKEY_get0_param()
153return 1 for success and 0 if an error occurred.
154
155X509_PUBKEY_eq() returns 1 for equal, 0 for different, and < 0 on error.
156
157=head1 SEE ALSO
158
159L<d2i_X509(3)>,
160L<ERR_get_error(3)>,
161L<X509_get_pubkey(3)>,
162
163=head1 HISTORY
164
165The X509_PUBKEY_new_ex() and X509_PUBKEY_eq() functions were added in OpenSSL
1663.0.
167
168The X509_PUBKEY_set0_public_key(), d2i_PUBKEY_ex_bio() and d2i_PUBKEY_ex_fp()
169functions were added in OpenSSL 3.2.
170
171=head1 COPYRIGHT
172
173Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.
174
175Licensed under the Apache License 2.0 (the "License").  You may not use
176this file except in compliance with the License.  You can obtain a copy
177in the file LICENSE in the source distribution or at
178L<https://www.openssl.org/source/license.html>.
179
180=cut
181