Your task is to implement a REST API which:

1. Has two endpoints /encrypt and /decrypt. Each endpoint should take a JSON payload.

2. Use Base64 to implement encryption and decryption on the /encrypt and /decrypt endpoints respectively.

   • /encrypt should encrypt every value in the object (at a depth of 1), returning the encrypted payload as JSON.
   • /decrypt should detect encrypted strings and decrypt them, returning the decrypted payload as JSON.

   For example:

   {
     "foo": "foobar",
     "bar": {
       "isBar": true
     }
   }

   would become

   {
     "foo": "some_encrypted_string",
     "bar": "some_encrypted_string"
   }

3. The Base64 encryption algorithm should be easily replaceable with another algorithm without requiring significant changes to the codebase.

4. Create a /sign endpoint which takes a JSON payload and computes a cryptographic signature for the plaintext payload in HMAC. The signature is then sent in a JSON response.

5. Create a /verify endpoint, which takes a JSON payload of the form

{
   "signature": "<COMPUTED_SIGNATURE>",
   "data": {
      // ...
   }
}

• Data can be any JSON object and can contain encrypted fields.
• If the provided signature matches the computed signature, the response code should be 204; otherwise, it should be 400.

Send me the project, your GitHub repository by email [email protected].