Name

X509_NAME_get_index_by_NID, X509_NAME_get_index_by_OBJ
X509_NAME_get_entry, X509_NAME_entry_count
X509_NAME_get_text_by_NID, X509_NAME_get_text_by_OBJ

X509_NAME lookup and enumeration functions

Library

libcrypto.lib

Synopsis

int X509_NAME_get_index_by_NID(X509_NAME *name,int nid,int lastpos); 
int X509_NAME_get_index_by_OBJ(X509_NAME *name,ASN1_OBJECT *obj, int lastpos);

int X509_NAME_entry_count(X509_NAME *name); X509_NAME_ENTRY *X509_NAME_get_entry(X509_NAME *name, int loc);

int X509_NAME_get_text_by_NID(X509_NAME *name, int nid, char *buf,int len); 
int X509_NAME_get_text_by_OBJ(X509_NAME *name, ASN1_OBJECT *obj, char *buf,int len);

Detailed Description

These functions allow an X509_NAME structure to be examined. The X509_NAME structure is the same as the Name type defined in RFC2459 (and elsewhere) and used for example in certificate subject and issuer names.

X509_NAME_get_index_by_NID() and X509_NAME_get_index_by_OBJ() retrieve the next index matching nid or obj after lastpos. lastpos should initially be set to -1. If there are no more entries -1 is returned.

X509_NAME_entry_count() returns the total number of entries in name.

X509_NAME_get_entry() retrieves the X509_NAME_ENTRY from name corresponding to index loc. Acceptable values for loc run from 0 to (X509_NAME_entry_count(name) - 1). The value returned is an internal pointer which must not be freed.

X509_NAME_get_text_by_NID(), X509_NAME_get_text_by_OBJ() retrieve the ``text'' from the first entry in name which matches nid or obj, if no such entry exists -1 is returned. At most len bytes will be written and the text written to buf will be null terminated. The length of the output string written is returned excluding the terminating null. If buf is <NULL> then the amount of space needed in buf (excluding the final null) is returned.

Examples

 int i;
 X509_NAME_ENTRY *e;

 for (i = 0; i < X509_NAME_entry_count(nm); i++)
        {
        e = X509_NAME_get_entry(nm, i);
        /* Do something with e */
        }

 int loc;
 X509_NAME_ENTRY *e;

 loc = -1;
 for (;;)
        {
        lastpos = X509_NAME_get_index_by_NID(nm, NID_commonName, lastpos);
        if (lastpos == -1)
                break;
        e = X509_NAME_get_entry(nm, lastpos);
        /* Do something with e */
        }

Notes

X509_NAME_get_text_by_NID() and X509_NAME_get_text_by_OBJ() are legacy functions which have various limitations which make them of minimal use in practice. They can only find the first matching entry and will copy the contents of the field verbatim: this can be highly confusing if the target is a muticharacter string type like a BMPString or a UTF8String.

For a more general solution X509_NAME_get_index_by_NID() or X509_NAME_get_index_by_OBJ() should be used followed by X509_NAME_get_entry() on any matching indices and then the various X509_NAME_ENTRY utility functions on the result.

Return Values

X509_NAME_get_index_by_NID() and X509_NAME_get_index_by_OBJ() return the index of the next matching entry or -1 if not found.

X509_NAME_entry_count() returns the total number of entries.

X509_NAME_get_entry() returns an X509_NAME pointer to the requested entry or NULL if the index is invalid.

See Also

ERR_get_error(), d2i_X509_NAME()

History

TBA

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