Blob UDFs

These UDFs can be used to encrypt and decrypt the data stored in the BLOB data type.

pty.ins_encrypt_blob

This function is used to encrypt the data stored in a BLOB with an encryption data element.

Signature:

pty.ins_encrypt_blob(dataelement CHAR, input_data BLOB , scid INTEGER)

Parameters:

Returns:
This UDF returns the encrypted value as the BLOB data. > Note: If you perform a protect operation with the input data as null or empty, then the output will be an empty_blob.

Exception:
If the user does not have protect privileges in the policy, then the UDF terminates with an error message explaining what went wrong.

Example:

select pty.ins_encrypt_blob('AES256',TO_BLOB('691F89CD2BCBF055EFD4F3B51470AEF6'),0) from dual;

Caution: A maximum of 1.5 GB of input data can be protected using the pty.ins_encrypt_blob UDF. The pty.ins_encrypt_blob UDF will return an unexpected behaviour if you exceed the maximum input data limit of 1.5 GB. For example: ORA-28579: network error during callback from external procedure agent.

pty.sel_decrypt_blob

This function is used to decrypt the encrypted data stored in a BLOB with an encryption data element.

Signature:

pty.sel_decrypt_blob (dataelement CHAR, input_data BLOB, scid INTEGER)

Parameters:

Returns:

• This UDF returns the decrypted value as the BLOB data.
• This UDF returns the decrypted value as an EMPTY_BLOB, when the user has no access to the database.

Note: If you perform a protect operation with the input data as null or empty, then the output will be an empty_blob.

Exception:
If the user does not have unprotect access rights in the policy, then the UDF terminates with an error message explaining what went wrong.

Example:

select pty.sel_decrypt_blob('AES256',pty.ins_encrypt_blob('AES256',TO_BLOB('691F89CD2BCBF055EFD4F3B51470AEF6'),0),0) from dual;