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(X509_NAME *name, int nid, int lastpos); 14 int X509_NAME_get_index_by_OBJ(X509_NAME *name, const ASN1_OBJECT *obj, int lastpos); 15 16 int X509_NAME_entry_count(const X509_NAME *name); 17 X509_NAME_ENTRY *X509_NAME_get_entry(const X509_NAME *name, int loc); 18 19 int X509_NAME_get_text_by_NID(X509_NAME *name, int nid, char *buf, int len); 20 int X509_NAME_get_text_by_OBJ(X509_NAME *name, const ASN1_OBJECT *obj, char *buf, int len); 21 22=head1 DESCRIPTION 23 24These functions allow an B<X509_NAME> structure to be examined. The 25B<X509_NAME> structure is the same as the B<Name> type defined in 26RFC2459 (and elsewhere) and used for example in certificate subject 27and issuer names. 28 29X509_NAME_get_index_by_NID() and X509_NAME_get_index_by_OBJ() retrieve 30the next index matching B<nid> or B<obj> after B<lastpos>. B<lastpos> 31should initially be set to -1. If there are no more entries -1 is returned. 32If B<nid> is invalid (doesn't correspond to a valid OID) then -2 is returned. 33 34X509_NAME_entry_count() returns the total number of entries in B<name>. 35 36X509_NAME_get_entry() retrieves the B<X509_NAME_ENTRY> from B<name> 37corresponding to index B<loc>. Acceptable values for B<loc> run from 380 to (X509_NAME_entry_count(name) - 1). The value returned is an 39internal pointer which must not be freed. 40 41X509_NAME_get_text_by_NID(), X509_NAME_get_text_by_OBJ() retrieve 42the "text" from the first entry in B<name> which matches B<nid> or 43B<obj>, if no such entry exists -1 is returned. At most B<len> bytes 44will be written and the text written to B<buf> will be null 45terminated. The length of the output string written is returned 46excluding the terminating null. If B<buf> is <NULL> then the amount 47of space needed in B<buf> (excluding the final null) is returned. 48 49=head1 NOTES 50 51X509_NAME_get_text_by_NID() and X509_NAME_get_text_by_OBJ() should be 52considered deprecated because they 53have various limitations which make them 54of minimal use in practice. They can only find the first matching 55entry and will copy the contents of the field verbatim: this can 56be highly confusing if the target is a multicharacter string type 57like a BMPString or a UTF8String. 58 59For a more general solution X509_NAME_get_index_by_NID() or 60X509_NAME_get_index_by_OBJ() should be used followed by 61X509_NAME_get_entry() on any matching indices and then the 62various B<X509_NAME_ENTRY> utility functions on the result. 63 64The list of all relevant B<NID_*> and B<OBJ_* codes> can be found in 65the source code header files E<lt>openssl/obj_mac.hE<gt> and/or 66E<lt>openssl/objects.hE<gt>. 67 68Applications which could pass invalid NIDs to X509_NAME_get_index_by_NID() 69should check for the return value of -2. Alternatively the NID validity 70can be determined first by checking OBJ_nid2obj(nid) is not NULL. 71 72=head1 RETURN VALUES 73 74X509_NAME_get_index_by_NID() and X509_NAME_get_index_by_OBJ() 75return the index of the next matching entry or -1 if not found. 76X509_NAME_get_index_by_NID() can also return -2 if the supplied 77NID is invalid. 78 79X509_NAME_entry_count() returns the total number of entries. 80 81X509_NAME_get_entry() returns an B<X509_NAME> pointer to the 82requested entry or B<NULL> if the index is invalid. 83 84=head1 EXAMPLES 85 86Process all entries: 87 88 int i; 89 X509_NAME_ENTRY *e; 90 91 for (i = 0; i < X509_NAME_entry_count(nm); i++) { 92 e = X509_NAME_get_entry(nm, i); 93 /* Do something with e */ 94 } 95 96Process all commonName entries: 97 98 int lastpos = -1; 99 X509_NAME_ENTRY *e; 100 101 for (;;) { 102 lastpos = X509_NAME_get_index_by_NID(nm, NID_commonName, lastpos); 103 if (lastpos == -1) 104 break; 105 e = X509_NAME_get_entry(nm, lastpos); 106 /* Do something with e */ 107 } 108 109=head1 SEE ALSO 110 111L<ERR_get_error(3)>, L<d2i_X509_NAME(3)> 112 113=head1 COPYRIGHT 114 115Copyright 2002-2019 The OpenSSL Project Authors. All Rights Reserved. 116 117Licensed under the OpenSSL license (the "License"). You may not use 118this file except in compliance with the License. You can obtain a copy 119in the file LICENSE in the source distribution or at 120L<https://www.openssl.org/source/license.html>. 121 122=cut 123