When X509_OCTET_STRING is used for the lpszStructType with CryptEncodeObject, CryptEncodeObjectEx, CryptDecodeObject, or CryptDecodeObjectEx the following details apply.
N/A
pvStructInfo points to a CRYPT_DATA_BLOB structure. See BLOB Structure.
The BLOB Structure contains an octet string, an arbitrary sequence of bytes. A common usage is for some encryption algorithms that take an initialization vector, in the form of an octet string. See CRYPT_ALGORITHM_IDENTIFIER.