X509_NAME_get_index_by_NID.pod revision 279264 
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,ASN1_OBJECT *obj, int lastpos);
15
16 int X509_NAME_entry_count(X509_NAME *name);
17 X509_NAME_ENTRY *X509_NAME_get_entry(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, 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.
32
33X509_NAME_entry_count() returns the total number of entries in B<name>.
34
35X509_NAME_get_entry() retrieves the B<X509_NAME_ENTRY> from B<name>
36corresponding to index B<loc>. Acceptable values for B<loc> run from
370 to (X509_NAME_entry_count(name) - 1). The value returned is an
38internal pointer which must not be freed.
39
40X509_NAME_get_text_by_NID(), X509_NAME_get_text_by_OBJ() retrieve
41the "text" from the first entry in B<name> which matches B<nid> or
42B<obj>, if no such entry exists -1 is returned. At most B<len> bytes
43will be written and the text written to B<buf> will be null
44terminated. The length of the output string written is returned
45excluding the terminating null. If B<buf> is <NULL> then the amount
46of space needed in B<buf> (excluding the final null) is returned. 
47
48=head1 NOTES
49
50X509_NAME_get_text_by_NID() and X509_NAME_get_text_by_OBJ() are
51legacy functions which have various limitations which make them
52of minimal use in practice. They can only find the first matching
53entry and will copy the contents of the field verbatim: this can
54be highly confusing if the target is a muticharacter string type
55like a BMPString or a UTF8String.
56
57For a more general solution X509_NAME_get_index_by_NID() or
58X509_NAME_get_index_by_OBJ() should be used followed by
59X509_NAME_get_entry() on any matching indices and then the
60various B<X509_NAME_ENTRY> utility functions on the result.
61
62The list of all relevant B<NID_*> and B<OBJ_* codes> can be found in
63the source code header files E<lt>openssl/obj_mac.hE<gt> and/or
64E<lt>openssl/objects.hE<gt>.
65
66=head1 EXAMPLES
67
68Process all entries:
69
70 int i;
71 X509_NAME_ENTRY *e;
72
73 for (i = 0; i < X509_NAME_entry_count(nm); i++)
74	{
75	e = X509_NAME_get_entry(nm, i);
76	/* Do something with e */
77	}
78
79Process all commonName entries:
80
81 int loc;
82 X509_NAME_ENTRY *e;
83
84 loc = -1;
85 for (;;)
86	{
87	lastpos = X509_NAME_get_index_by_NID(nm, NID_commonName, lastpos);
88	if (lastpos == -1)
89		break;
90	e = X509_NAME_get_entry(nm, lastpos);
91	/* Do something with e */
92	}
93
94=head1 RETURN VALUES
95
96X509_NAME_get_index_by_NID() and X509_NAME_get_index_by_OBJ()
97return the index of the next matching entry or -1 if not found.
98
99X509_NAME_entry_count() returns the total number of entries.
100
101X509_NAME_get_entry() returns an B<X509_NAME> pointer to the
102requested entry or B<NULL> if the index is invalid.
103
104=head1 SEE ALSO
105
106L<ERR_get_error(3)|ERR_get_error(3)>, L<d2i_X509_NAME(3)|d2i_X509_NAME(3)>
107
108=head1 HISTORY
109
110TBA
111
112=cut
113