1X509_GET_EXTENSION_FLAGS(3) OpenSSL X509_GET_EXTENSION_FLAGS(3)
2
6 X509_get0_subject_key_id, X509_get0_authority_key_id,
7 X509_get0_authority_issuer, X509_get0_authority_serial,
8 X509_get_pathlen, X509_get_extension_flags, X509_get_key_usage,
9 X509_get_extended_key_usage, X509_set_proxy_flag,
10 X509_set_proxy_pathlen, X509_get_proxy_pathlen - retrieve certificate
11 extension data
12
14 #include <openssl/x509v3.h>
15 long X509_get_pathlen(X509 *x);
17 uint32_t X509_get_extension_flags(X509 *x);
18 uint32_t X509_get_key_usage(X509 *x);
19 uint32_t X509_get_extended_key_usage(X509 *x);
20 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x);
21 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x);
22 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x);
23 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x);
24 void X509_set_proxy_flag(X509 *x);
25 void X509_set_proxy_pathlen(int l);
26 long X509_get_proxy_pathlen(X509 *x);
27
29 These functions retrieve information related to commonly used
30 certificate extensions.
31 X509_get_pathlen() retrieves the path length extension from a
33 certificate. This extension is used to limit the length of a cert
34 chain that may be issued from that CA.
35 X509_get_extension_flags() retrieves general information about a
37 certificate, it will return one or more of the following flags ored
38 together.
39 EXFLAG_V1
41 The certificate is an obsolete version 1 certificate.
42 EXFLAG_BCONS
44 The certificate contains a basic constraints extension.
45 EXFLAG_CA
47 The certificate contains basic constraints and asserts the CA flag.
48 EXFLAG_PROXY
50 The certificate is a valid proxy certificate.
51 EXFLAG_SI
53 The certificate is self issued (that is subject and issuer names
54 match).
55 EXFLAG_SS
57 The subject and issuer names match and extension values imply it is
58 self signed.
59 EXFLAG_FRESHEST
61 The freshest CRL extension is present in the certificate.
62 EXFLAG_CRITICAL
64 The certificate contains an unhandled critical extension.
65 EXFLAG_INVALID
67 Some certificate extension values are invalid or inconsistent. The
68 certificate should be rejected. This bit may also be raised after
69 an out-of-memory error while processing the X509 object, so it may
70 not be related to the processed ASN1 object itself.
71 EXFLAG_NO_FINGERPRINT
73 Failed to compute the internal SHA1 hash value of the certificate.
74 This may be due to malloc failure or because no SHA1 implementation
75 was found.
76 EXFLAG_INVALID_POLICY
78 The NID_certificate_policies certificate extension is invalid or
79 inconsistent. The certificate should be rejected. This bit may
80 also be raised after an out-of-memory error while processing the
81 X509 object, so it may not be related to the processed ASN1 object
82 itself.
83 EXFLAG_KUSAGE
85 The certificate contains a key usage extension. The value can be
86 retrieved using X509_get_key_usage().
87 EXFLAG_XKUSAGE
89 The certificate contains an extended key usage extension. The value
90 can be retrieved using X509_get_extended_key_usage().
91 X509_get_key_usage() returns the value of the key usage extension. If
93 key usage is present will return zero or more of the flags:
94 KU_DIGITAL_SIGNATURE, KU_NON_REPUDIATION, KU_KEY_ENCIPHERMENT,
95 KU_DATA_ENCIPHERMENT, KU_KEY_AGREEMENT, KU_KEY_CERT_SIGN, KU_CRL_SIGN,
96 KU_ENCIPHER_ONLY or KU_DECIPHER_ONLY corresponding to individual key
97 usage bits. If key usage is absent then UINT32_MAX is returned.
98 X509_get_extended_key_usage() returns the value of the extended key
100 usage extension. If extended key usage is present it will return zero
101 or more of the flags: XKU_SSL_SERVER, XKU_SSL_CLIENT, XKU_SMIME,
102 XKU_CODE_SIGN XKU_OCSP_SIGN, XKU_TIMESTAMP, XKU_DVCS or XKU_ANYEKU.
103 These correspond to the OIDs id-kp-serverAuth, id-kp-clientAuth, id-kp-
104 emailProtection, id-kp-codeSigning, id-kp-OCSPSigning, id-kp-
105 timeStamping, id-kp-dvcs and anyExtendedKeyUsage respectively.
106 Additionally XKU_SGC is set if either Netscape or Microsoft SGC OIDs
107 are present.
108 X509_get0_subject_key_id() returns an internal pointer to the subject
110 key identifier of x as an ASN1_OCTET_STRING or NULL if the extension is
111 not present or cannot be parsed.
112 X509_get0_authority_key_id() returns an internal pointer to the
114 authority key identifier of x as an ASN1_OCTET_STRING or NULL if the
115 extension is not present or cannot be parsed.
116 X509_get0_authority_issuer() returns an internal pointer to the
118 authority certificate issuer of x as a stack of GENERAL_NAME structures
119 or NULL if the extension is not present or cannot be parsed.
120 X509_get0_authority_serial() returns an internal pointer to the
122 authority certificate serial number of x as an ASN1_INTEGER or NULL if
123 the extension is not present or cannot be parsed.
124 X509_set_proxy_flag() marks the certificate with the EXFLAG_PROXY flag.
126 This is for the users who need to mark non-RFC3820 proxy certificates
127 as such, as OpenSSL only detects RFC3820 compliant ones.
128 X509_set_proxy_pathlen() sets the proxy certificate path length for the
130 given certificate x. This is for the users who need to mark
131 non-RFC3820 proxy certificates as such, as OpenSSL only detects RFC3820
132 compliant ones.
133 X509_get_proxy_pathlen() returns the proxy certificate path length for
135 the given certificate x if it is a proxy certificate.
136
138 The value of the flags correspond to extension values which are cached
139 in the X509 structure. If the flags returned do not provide sufficient
140 information an application should examine extension values directly for
141 example using X509_get_ext_d2i().
142 If the key usage or extended key usage extension is absent then
144 typically usage is unrestricted. For this reason X509_get_key_usage()
145 and X509_get_extended_key_usage() return UINT32_MAX when the
146 corresponding extension is absent. Applications can additionally check
147 the return value of X509_get_extension_flags() and take appropriate
148 action is an extension is absent.
149 If X509_get0_subject_key_id() returns NULL then the extension may be
151 absent or malformed. Applications can determine the precise reason
152 using X509_get_ext_d2i().
153
155 X509_get_pathlen() returns the path length value, or -1 if the
156 extension is not present.
157 X509_get_extension_flags(), X509_get_key_usage() and
159 X509_get_extended_key_usage() return sets of flags corresponding to the
160 certificate extension values.
161 X509_get0_subject_key_id() returns the subject key identifier as a
163 pointer to an ASN1_OCTET_STRING structure or NULL if the extension is
164 absent or an error occurred during parsing.
165 X509_get_proxy_pathlen() returns the path length value if the given
167 certificate is a proxy one and has a path length set, and -1 otherwise.
168
170 X509_check_purpose(3)
171
173 X509_get_pathlen(), X509_set_proxy_flag(), X509_set_proxy_pathlen() and
174 X509_get_proxy_pathlen() were added in OpenSSL 1.1.0.
175
177 Copyright 2015-2021 The OpenSSL Project Authors. All Rights Reserved.
178 Licensed under the OpenSSL license (the "License"). You may not use
180 this file except in compliance with the License. You can obtain a copy
181 in the file LICENSE in the source distribution or at
182 <https://www.openssl.org/source/license.html>.
1831.1.1q 2022-07-07 X509_GET_EXTENSION_FLAGS(3)