1=pod 2 3=head1 NAME 4 5X509_NAME_get_index_by_NID, X509_NAME_get_index_by_OBJ, X509_NAME_get_entry, 6X509_NAME_entry_count, X509_NAME_get_text_by_NID, X509_NAME_get_text_by_OBJ - 7X509_NAME lookup and enumeration functions 8 9=head1 SYNOPSIS 10 11 #include <openssl/x509.h> 12 13 int X509_NAME_get_index_by_NID(const X509_NAME *name, int nid, int lastpos); 14 int X509_NAME_get_index_by_OBJ(const X509_NAME *name, 15 const ASN1_OBJECT *obj, int lastpos); 16 17 int X509_NAME_entry_count(const X509_NAME *name); 18 X509_NAME_ENTRY *X509_NAME_get_entry(const X509_NAME *name, int loc); 19 20 int X509_NAME_get_text_by_NID(const X509_NAME *name, int nid, 21 char *buf, int len); 22 int X509_NAME_get_text_by_OBJ(const X509_NAME *name, const ASN1_OBJECT *obj, 23 char *buf, int len); 24 25=head1 DESCRIPTION 26 27These functions allow an B<X509_NAME> structure to be examined. The 28B<X509_NAME> structure is the same as the B<Name> type defined in 29RFC2459 (and elsewhere) and used for example in certificate subject 30and issuer names. 31 32X509_NAME_get_index_by_NID() and X509_NAME_get_index_by_OBJ() retrieve 33the next index matching B<nid> or B<obj> after B<lastpos>. B<lastpos> 34should initially be set to -1. If there are no more entries -1 is returned. 35If B<nid> is invalid (doesn't correspond to a valid OID) then -2 is returned. 36 37X509_NAME_entry_count() returns the total number of entries in B<name>. 38 39X509_NAME_get_entry() retrieves the B<X509_NAME_ENTRY> from B<name> 40corresponding to index B<loc>. Acceptable values for B<loc> run from 410 to (X509_NAME_entry_count(name) - 1). The value returned is an 42internal pointer which must not be freed. 43 44X509_NAME_get_text_by_NID(), X509_NAME_get_text_by_OBJ() retrieve 45the "text" from the first entry in B<name> which matches B<nid> or 46B<obj>, if no such entry exists -1 is returned. At most B<len> bytes 47will be written and the text written to B<buf> will be null 48terminated. The length of the output string written is returned 49excluding the terminating null. If B<buf> is <NULL> then the amount 50of space needed in B<buf> (excluding the final null) is returned. 51 52=head1 NOTES 53 54X509_NAME_get_text_by_NID() and X509_NAME_get_text_by_OBJ() should be 55considered deprecated because they 56have various limitations which make them 57of minimal use in practice. They can only find the first matching 58entry and will copy the contents of the field verbatim: this can 59be highly confusing if the target is a multicharacter string type 60like a BMPString or a UTF8String. 61 62For a more general solution X509_NAME_get_index_by_NID() or 63X509_NAME_get_index_by_OBJ() should be used followed by 64X509_NAME_get_entry() on any matching indices and then the 65various B<X509_NAME_ENTRY> utility functions on the result. 66 67The list of all relevant B<NID_*> and B<OBJ_* codes> can be found in 68the source code header files F<< <openssl/obj_mac.h> >> and/or 69F<< <openssl/objects.h> >>. 70 71Applications which could pass invalid NIDs to X509_NAME_get_index_by_NID() 72should check for the return value of -2. Alternatively the NID validity 73can be determined first by checking OBJ_nid2obj(nid) is not NULL. 74 75=head1 RETURN VALUES 76 77X509_NAME_get_index_by_NID() and X509_NAME_get_index_by_OBJ() 78return the index of the next matching entry or -1 if not found. 79X509_NAME_get_index_by_NID() can also return -2 if the supplied 80NID is invalid. 81 82X509_NAME_entry_count() returns the total number of entries. 83 84X509_NAME_get_entry() returns an B<X509_NAME> pointer to the 85requested entry or B<NULL> if the index is invalid. 86 87=head1 EXAMPLES 88 89Process all entries: 90 91 int i; 92 X509_NAME_ENTRY *e; 93 94 for (i = 0; i < X509_NAME_entry_count(nm); i++) { 95 e = X509_NAME_get_entry(nm, i); 96 /* Do something with e */ 97 } 98 99Process all commonName entries: 100 101 int lastpos = -1; 102 X509_NAME_ENTRY *e; 103 104 for (;;) { 105 lastpos = X509_NAME_get_index_by_NID(nm, NID_commonName, lastpos); 106 if (lastpos == -1) 107 break; 108 e = X509_NAME_get_entry(nm, lastpos); 109 /* Do something with e */ 110 } 111 112=head1 SEE ALSO 113 114L<ERR_get_error(3)>, L<d2i_X509_NAME(3)> 115 116=head1 COPYRIGHT 117 118Copyright 2002-2021 The OpenSSL Project Authors. All Rights Reserved. 119 120Licensed under the Apache License 2.0 (the "License"). You may not use 121this file except in compliance with the License. You can obtain a copy 122in the file LICENSE in the source distribution or at 123L<https://www.openssl.org/source/license.html>. 124 125=cut 126