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.