1=pod 2 3=head1 NAME 4 5X509v3_get_ext_count, X509v3_get_ext, X509v3_get_ext_by_NID, 6X509v3_get_ext_by_OBJ, X509v3_get_ext_by_critical, X509v3_delete_ext, 7X509v3_add_ext, X509_get_ext_count, X509_get_ext, 8X509_get_ext_by_NID, X509_get_ext_by_OBJ, X509_get_ext_by_critical, 9X509_delete_ext, X509_add_ext, X509_CRL_get_ext_count, X509_CRL_get_ext, 10X509_CRL_get_ext_by_NID, X509_CRL_get_ext_by_OBJ, X509_CRL_get_ext_by_critical, 11X509_CRL_delete_ext, X509_CRL_add_ext, X509_REVOKED_get_ext_count, 12X509_REVOKED_get_ext, X509_REVOKED_get_ext_by_NID, X509_REVOKED_get_ext_by_OBJ, 13X509_REVOKED_get_ext_by_critical, X509_REVOKED_delete_ext, 14X509_REVOKED_add_ext - extension stack utility functions 15 16=head1 SYNOPSIS 17 18 #include <openssl/x509.h> 19 20 int X509v3_get_ext_count(const STACK_OF(X509_EXTENSION) *x); 21 X509_EXTENSION *X509v3_get_ext(const STACK_OF(X509_EXTENSION) *x, int loc); 22 23 int X509v3_get_ext_by_NID(const STACK_OF(X509_EXTENSION) *x, 24 int nid, int lastpos); 25 int X509v3_get_ext_by_OBJ(const STACK_OF(X509_EXTENSION) *x, 26 const ASN1_OBJECT *obj, int lastpos); 27 int X509v3_get_ext_by_critical(const STACK_OF(X509_EXTENSION) *x, 28 int crit, int lastpos); 29 X509_EXTENSION *X509v3_delete_ext(STACK_OF(X509_EXTENSION) *x, int loc); 30 STACK_OF(X509_EXTENSION) *X509v3_add_ext(STACK_OF(X509_EXTENSION) **x, 31 X509_EXTENSION *ex, int loc); 32 33 int X509_get_ext_count(const X509 *x); 34 X509_EXTENSION *X509_get_ext(const X509 *x, int loc); 35 int X509_get_ext_by_NID(const X509 *x, int nid, int lastpos); 36 int X509_get_ext_by_OBJ(const X509 *x, const ASN1_OBJECT *obj, int lastpos); 37 int X509_get_ext_by_critical(const X509 *x, int crit, int lastpos); 38 X509_EXTENSION *X509_delete_ext(X509 *x, int loc); 39 int X509_add_ext(X509 *x, X509_EXTENSION *ex, int loc); 40 41 int X509_CRL_get_ext_count(const X509_CRL *x); 42 X509_EXTENSION *X509_CRL_get_ext(const X509_CRL *x, int loc); 43 int X509_CRL_get_ext_by_NID(const X509_CRL *x, int nid, int lastpos); 44 int X509_CRL_get_ext_by_OBJ(const X509_CRL *x, const ASN1_OBJECT *obj, 45 int lastpos); 46 int X509_CRL_get_ext_by_critical(const X509_CRL *x, int crit, int lastpos); 47 X509_EXTENSION *X509_CRL_delete_ext(X509_CRL *x, int loc); 48 int X509_CRL_add_ext(X509_CRL *x, X509_EXTENSION *ex, int loc); 49 50 int X509_REVOKED_get_ext_count(const X509_REVOKED *x); 51 X509_EXTENSION *X509_REVOKED_get_ext(const X509_REVOKED *x, int loc); 52 int X509_REVOKED_get_ext_by_NID(const X509_REVOKED *x, int nid, int lastpos); 53 int X509_REVOKED_get_ext_by_OBJ(const X509_REVOKED *x, const ASN1_OBJECT *obj, 54 int lastpos); 55 int X509_REVOKED_get_ext_by_critical(const X509_REVOKED *x, int crit, int lastpos); 56 X509_EXTENSION *X509_REVOKED_delete_ext(X509_REVOKED *x, int loc); 57 int X509_REVOKED_add_ext(X509_REVOKED *x, X509_EXTENSION *ex, int loc); 58 59=head1 DESCRIPTION 60 61X509v3_get_ext_count() retrieves the number of extensions in I<x>. 62 63X509v3_get_ext() retrieves extension I<loc> from I<x>. The index I<loc> 64can take any value from 0 to X509_get_ext_count(I<x>) - 1. The returned 65extension is an internal pointer which B<MUST NOT> be freed by the 66application. 67 68X509v3_get_ext_by_NID() and X509v3_get_ext_by_OBJ() look for an extension 69with I<nid> or I<obj> from extension STACK I<x>. The search starts from the 70extension after I<lastpos> or from the beginning if I<lastpos> is -1. If 71the extension is found, its index is returned, otherwise -1 is returned. 72 73X509v3_get_ext_by_critical() is similar to X509v3_get_ext_by_NID() except it 74looks for an extension of criticality I<crit>. A zero value for I<crit> 75looks for a non-critical extension. A nonzero value looks for a critical 76extension. 77 78X509v3_delete_ext() deletes the extension with index I<loc> from I<x>. 79The deleted extension is returned and must be freed by the caller. 80If I<loc> is an invalid index value, NULL is returned. 81 82X509v3_add_ext() adds extension I<ex> to STACK I<*x> at position I<loc>. If 83I<loc> is -1, the new extension is added to the end. If I<*x> is NULL, 84a new STACK will be allocated. The passed extension I<ex> is duplicated 85internally so it must be freed after use. 86 87X509_get_ext_count(), X509_get_ext(), X509_get_ext_by_NID(), 88X509_get_ext_by_OBJ(), X509_get_ext_by_critical(), X509_delete_ext() 89and X509_add_ext() operate on the extensions of certificate I<x>. They are 90otherwise identical to the X509v3 functions. 91 92X509_CRL_get_ext_count(), X509_CRL_get_ext(), X509_CRL_get_ext_by_NID(), 93X509_CRL_get_ext_by_OBJ(), X509_CRL_get_ext_by_critical(), 94X509_CRL_delete_ext() and X509_CRL_add_ext() operate on the extensions of 95CRL I<x>. They are otherwise identical to the X509v3 functions. 96 97X509_REVOKED_get_ext_count(), X509_REVOKED_get_ext(), 98X509_REVOKED_get_ext_by_NID(), X509_REVOKED_get_ext_by_OBJ(), 99X509_REVOKED_get_ext_by_critical(), X509_REVOKED_delete_ext() and 100X509_REVOKED_add_ext() operate on the extensions of CRL entry I<x>. 101They are otherwise identical to the X509v3 functions. 102 103=head1 NOTES 104 105These functions are used to examine stacks of extensions directly. 106Applications that want to parse or encode and add an extension should 107use the extension encode and decode functions instead, such as 108X509_add1_ext_i2d() and X509_get_ext_d2i(). 109 110For X509v3_get_ext_by_NID(), X509v3_get_ext_by_OBJ(), 111X509v3_get_ext_by_critical() and its variants, a zero index return value 112is not an error since extension STACK I<x> indices start from zero. 113These search functions start from the extension B<after> the I<lastpos> parameter 114so it should initially be set to -1. If it is set to zero, the initial extension 115will not be checked. 116 117X509v3_delete_ext() and its variants are a bit counter-intuitive 118because these functions do not free the extension they delete. 119They return an B<X509_EXTENSION> object which must be explicitly freed 120using X509_EXTENSION_free(). 121 122=head1 RETURN VALUES 123 124X509v3_get_ext_count() returns the extension count or 0 for failure. 125 126X509v3_get_ext(), X509v3_delete_ext() and X509_delete_ext() return an 127B<X509_EXTENSION> structure or NULL if an error occurs. 128 129X509v3_get_ext_by_OBJ() and X509v3_get_ext_by_critical() return 130the extension index or -1 if an error occurs. 131 132X509v3_get_ext_by_NID() returns the extension index or negative values if an 133error occurs. 134 135X509v3_add_ext() returns a STACK of extensions or NULL on error. 136 137X509_add_ext() returns 1 on success and 0 on error. 138 139=head1 SEE ALSO 140 141L<X509V3_get_d2i(3)> 142 143=head1 COPYRIGHT 144 145Copyright 2015-2022 The OpenSSL Project Authors. All Rights Reserved. 146 147Licensed under the Apache License 2.0 (the "License"). You may not use 148this file except in compliance with the License. You can obtain a copy 149in the file LICENSE in the source distribution or at 150L<https://www.openssl.org/source/license.html>. 151 152=cut 153