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Description

The ORA-28434 error occurs when Oracle attempts to decrypt a data file that has not been encrypted. This usually happens when there's a configuration issue or a mismatch between encryption settings and the actual data file.

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Error Message

ORA-28434: cannot decrypt an unencrypted data file string

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Known Causes

3 known causes

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Incorrect Tablespace Assignment

The data file might be incorrectly assigned to an encrypted tablespace while not actually being encrypted.

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Configuration Mismatch

There could be a mismatch between the tablespace encryption settings and the actual encryption status of the data file.

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Accidental Decryption Attempt

A process or script might be attempting to decrypt the file unintentionally.

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Solutions

4 solutions available

1. Verify Encryption Status of Data Files easy

Check if the data files are actually encrypted before attempting decryption.

1

Connect to the Oracle database as a user with sufficient privileges (e.g., SYSDBA or a user with SELECT_CATALOG_ROLE).

2

Query the `DBA_ENCRYPTED_COLUMNS` view to see which columns are encrypted. If the data file in question is part of a tablespace containing unencrypted columns, this error might occur if you're misinterpreting the encryption context.

SELECT owner, table_name, column_name, encryption_type, encrypt_state FROM DBA_ENCRYPTED_COLUMNS WHERE DECRYPT_STATE = 'NEVER' OR DECRYPT_STATE = 'UNENCRYPTED';

3

If the data file is associated with tablespaces managed by Transparent Data Encryption (TDE) for tablespaces, check the `V$ENCRYPTION_KEYS` and `DBA_TABLESPACES` views for encryption status.

SELECT * FROM V$ENCRYPTION_KEYS;
SELECT tablespace_name, encrypted FROM DBA_TABLESPACES WHERE encrypted = 'NO';

4

If the data files are not encrypted, then the attempt to decrypt them is the root cause. You should not be trying to decrypt unencrypted data. Re-evaluate the process that triggered this error.

2. Correctly Encrypt Data Files Before Decryption medium

Ensure data files are properly encrypted before attempting decryption operations.

1

Identify the data files that you intend to decrypt. The error message should provide a file identifier or name.

2

If you are using Oracle TDE for tablespaces, ensure the tablespace associated with the data file is actually encrypted. If it's not, you need to encrypt it first. This typically involves using the `ALTER TABLESPACE ... ENCRYPTION` command.

ALTER TABLESPACE YOUR_TABLESPACE_NAME ENCRYPTION USING 'AES256' ENCRYPT BY 'YOUR_KEY_NAME';

3

If you are dealing with encrypted columns, ensure the columns are encrypted using the `ALTER TABLE ... MODIFY ... ENCRYPT USING` command.

ALTER TABLE YOUR_TABLE_NAME MODIFY (YOUR_COLUMN_NAME ENCRYPT USING 'AES256' ENCRYPT BY 'YOUR_KEY_NAME');

4

Once the data files/tables/columns are confirmed to be encrypted, you can proceed with decryption operations using the appropriate commands (e.g., `ALTER TABLESPACE ... DECRYPTION`, `ALTER TABLE ... MODIFY ... DECRYPT`).

ALTER TABLESPACE YOUR_TABLESPACE_NAME DECRYPTION;
ALTER TABLE YOUR_TABLE_NAME MODIFY (YOUR_COLUMN_NAME DECRYPT);

3. Review and Correct Encryption Key Management advanced

Ensure the correct encryption keys are available and accessible for decryption.

1

Verify that the Oracle Wallet or Keystore containing the encryption keys is accessible to the database instance.

2

Confirm that the encryption key used to encrypt the data file is still valid and has not expired or been revoked.

3

If you are using Oracle Key Vault (OKV) or an external Key Management System (KMS), ensure the database has proper connectivity and authentication to access the encryption keys.

4

Check the Oracle alert log for any messages related to key retrieval failures or authentication issues with the wallet/keystore/KMS.

5

If keys are missing or corrupted, you may need to restore them from a backup or re-key the affected data if recovery is not possible. This is a critical operation and requires careful planning.

4. Investigate the Decryption Process Trigger medium

Determine what process or command is attempting to decrypt unencrypted data.

1

Examine the application logs, database audit logs, or any scripts that were recently executed. Look for commands or operations that involve decryption.

2

If you are using Oracle Data Pump (impdp/expdp) with encryption options, review the import or export command parameters to ensure they are correctly specified.

3

If you have custom scripts or procedures that interact with encrypted data, review their logic to identify where the decryption attempt is occurring.

4

If the error occurs during database startup or recovery, check the `INIT.ORA` or SPFILE parameters related to encryption and TDE. Ensure they are correctly configured.

5

Once the source of the incorrect decryption attempt is identified, correct the process or command to either perform encryption correctly or to not attempt decryption on unencrypted data.

Oracle ORA-28434: Unencrypted Data Decryption