X509_NAME_get_index_by_NID(3)

     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

     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);

     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.

     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.

     EXAMPLES
          Process all entries:

           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 */
                  }

          Process all commonName entries:

           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 */
                  }


     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(3), d2i_X509_NAME(3)

     HISTORY
          TBA