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The whole code has more problems except the encoding.

1. You use encryption for passwords. Use hashing.
2. Your encryption algorithm is non-standard, super-weak, and it does not have separate secret data (a key) to be applied. By publishing its code here the encryption is already compromised.

3. To the concrete problem: You may encode the problematic strings using base64 before storing within the password field, on reading apply base64 decoding. This is not a solution, better try to refactor the whole password related code.