xref: /openssl/doc/man3/X509_get0_signature.pod (revision 57cd10dd)
1=pod
2
3=head1 NAME
4
5X509_get0_signature, X509_REQ_set0_signature, X509_REQ_set1_signature_algo,
6X509_get_signature_nid, X509_get0_tbs_sigalg, X509_REQ_get0_signature,
7X509_REQ_get_signature_nid, X509_CRL_get0_signature, X509_CRL_get_signature_nid,
8X509_get_signature_info, X509_SIG_INFO_get, X509_SIG_INFO_set - signature information
9
10=head1 SYNOPSIS
11
12 #include <openssl/x509.h>
13
14 void X509_get0_signature(const ASN1_BIT_STRING **psig,
15                          const X509_ALGOR **palg,
16                          const X509 *x);
17 void X509_REQ_set0_signature(X509_REQ *req, ASN1_BIT_STRING *psig);
18 int X509_REQ_set1_signature_algo(X509_REQ *req, X509_ALGOR *palg);
19 int X509_get_signature_nid(const X509 *x);
20 const X509_ALGOR *X509_get0_tbs_sigalg(const X509 *x);
21
22 void X509_REQ_get0_signature(const X509_REQ *crl,
23                              const ASN1_BIT_STRING **psig,
24                              const X509_ALGOR **palg);
25 int X509_REQ_get_signature_nid(const X509_REQ *crl);
26
27 void X509_CRL_get0_signature(const X509_CRL *crl,
28                              const ASN1_BIT_STRING **psig,
29                              const X509_ALGOR **palg);
30 int X509_CRL_get_signature_nid(const X509_CRL *crl);
31
32 int X509_get_signature_info(X509 *x, int *mdnid, int *pknid, int *secbits,
33                             uint32_t *flags);
34
35 int X509_SIG_INFO_get(const X509_SIG_INFO *siginf, int *mdnid, int *pknid,
36                      int *secbits, uint32_t *flags);
37 void X509_SIG_INFO_set(X509_SIG_INFO *siginf, int mdnid, int pknid,
38                        int secbits, uint32_t flags);
39
40=head1 DESCRIPTION
41
42X509_get0_signature() sets B<*psig> to the signature of B<x> and B<*palg>
43to the signature algorithm of B<x>. The values returned are internal
44pointers which B<MUST NOT> be freed up after the call.
45
46X509_set0_signature() and X509_REQ_set1_signature_algo() are the
47equivalent setters for the two values of X509_get0_signature().
48
49X509_get0_tbs_sigalg() returns the signature algorithm in the signed
50portion of B<x>.
51
52X509_get_signature_nid() returns the NID corresponding to the signature
53algorithm of B<x>.
54
55X509_REQ_get0_signature(), X509_REQ_get_signature_nid()
56X509_CRL_get0_signature() and X509_CRL_get_signature_nid() perform the
57same function for certificate requests and CRLs.
58
59X509_get_signature_info() retrieves information about the signature of
60certificate B<x>. The NID of the signing digest is written to B<*mdnid>,
61the public key algorithm to B<*pknid>, the effective security bits to
62B<*secbits> and flag details to B<*flags>. Any of the parameters can
63be set to B<NULL> if the information is not required.
64
65X509_SIG_INFO_get() and X509_SIG_INFO_set() get and set information
66about a signature in an B<X509_SIG_INFO> structure. They are only
67used by implementations of algorithms which need to set custom
68signature information: most applications will never need to call
69them.
70
71=head1 NOTES
72
73These functions provide lower level access to signatures in certificates
74where an application wishes to analyse or generate a signature in a form
75where X509_sign() et al is not appropriate (for example a non standard
76or unsupported format).
77
78The security bits returned by X509_get_signature_info() refers to information
79available from the certificate signature (such as the signing digest). In some
80cases the actual security of the signature is less because the signing
81key is less secure: for example a certificate signed using SHA-512 and a
821024 bit RSA key.
83
84=head1 RETURN VALUES
85
86X509_get_signature_nid(), X509_REQ_get_signature_nid() and
87X509_CRL_get_signature_nid() return a NID.
88
89X509_get0_signature(), X509_REQ_get0_signature() and
90X509_CRL_get0_signature() do not return values.
91
92X509_get_signature_info() returns 1 if the signature information
93returned is valid or 0 if the information is not available (e.g.
94unknown algorithms or malformed parameters).
95
96X509_REQ_set1_signature_algo() returns 0 on success; or 1 on an
97error (e.g. null ALGO pointer). X509_REQ_set0_signature does
98not return an error value.
99
100=head1 SEE ALSO
101
102L<d2i_X509(3)>,
103L<ERR_get_error(3)>,
104L<X509_CRL_get0_by_serial(3)>,
105L<X509_get_ext_d2i(3)>,
106L<X509_get_extension_flags(3)>,
107L<X509_get_pubkey(3)>,
108L<X509_get_subject_name(3)>,
109L<X509_get_version(3)>,
110L<X509_NAME_add_entry_by_txt(3)>,
111L<X509_NAME_ENTRY_get_object(3)>,
112L<X509_NAME_get_index_by_NID(3)>,
113L<X509_NAME_print_ex(3)>,
114L<X509_new(3)>,
115L<X509_sign(3)>,
116L<X509V3_get_d2i(3)>,
117L<X509_verify_cert(3)>
118
119=head1 HISTORY
120
121The
122X509_get0_signature() and X509_get_signature_nid() functions were
123added in OpenSSL 1.0.2.
124
125The
126X509_REQ_get0_signature(), X509_REQ_get_signature_nid(),
127X509_CRL_get0_signature() and X509_CRL_get_signature_nid() were
128added in OpenSSL 1.1.0.
129
130The X509_REQ_set0_signature() and X509_REQ_set1_signature_algo()
131were added in OpenSSL 1.1.1e.
132
133=head1 COPYRIGHT
134
135Copyright 2015-2020 The OpenSSL Project Authors. All Rights Reserved.
136
137Licensed under the Apache License 2.0 (the "License").  You may not use
138this file except in compliance with the License.  You can obtain a copy
139in the file LICENSE in the source distribution or at
140L<https://www.openssl.org/source/license.html>.
141
142=cut
143