def _generate_blob_encryption_data(key_encryption_key):
encryption_data = None<EOL>content_encryption_key = None<EOL>initialization_vector = None<EOL>if key_encryption_key:<EOL><INDENT>_validate_key_encryption_key_wrap(key_encryption_key)<EOL>content_encryption_key = urandom(<NUM_LIT:32>)<EOL>initialization_vector = urandom(<NUM_LIT:16>)<EOL>encryption_data = _generate_encryption_data_dict(key_encryption_key,<EOL>content_encryption_key,<EOL>initialization_vector)<EOL>encryption_data['<STR_LIT>'] = '<STR_LIT>'<EOL>encryption_data = dumps(encryption_data)<EOL><DEDENT>return (content_encryption_key, initialization_vector, encryption_data)<EOL>
Generates the encryption_metadata for the blob.

:param bytes key_encryption_key:
    The key-encryption-key used to wrap the cek associate with this blob.
:return: A tuple containing the cek and iv for this blob as well as the 
    serialized encryption metadata for the blob.
:rtype: (bytes, bytes, str)