Expands an "OCTET STRING" element of a structure created from a DER
decoding process (the asn1_der_decoding() function). The type used
for expansion is the first one following the definition of the
actual value of the OBJECT IDENTIFIER indicated by OBJECTNAME.
ASN1_SUCCESS if substitution OK, ASN1_ELEMENT_NOT_FOUND
if objectName or octetName are not correct,
ASN1_VALUE_NOT_VALID if it wasnt possible to find the type to
use for expansion, or other errors depending on DER decoding.