Internet Banking System Decryption Service

Introduction

implemented an internal interface for an Internet Banking System. The interface is used as a "central point" of secure decryption of sensitive data.

The implementation of RSADecryptionService (all requirements are specified for the UTF-8 charset).

Requirements:

The byte[] decrypt(byte[] data) method decrypts data by using the RSA algorithm.
- When the data parameter is null or an array is empty, or the provided data is too long for the RSA algorithm, the method throws the InvalidDataLengthException.
- When the data passed as a parameter is incorrect (cannot be decrypted), the InvalidDataToDecryptException is thrown.
- Use the RSA 2048-bit private key (encoded according to the PKCS #8 standard) and the public key (encoded according to the X.509 standard) from src/main/resources.
The String decrypt(String dataAsBase64) method performs the same functionality and implement the same requirements as byte[] decrypt(byte[] data) but:
- The data is passed as Base64.
- When the data passed as a parameter is incorrect (incorrect Base64), the InvalidDataToDecryptException is thrown.
The byte[] sign(byte[] data) method signs the data passed as parameters with a digital RSA signature using the private key.
- If the data is null or empty, the method should throw the InvalidDataToDecryptException.
- The method should use the SHA256withRSA hash algorithm.