python_custom_curve.py

# 1. Fidelius CLI
# https://github.com/mgrmtech/fidelius-cli/tree/main/src/main/java/com/mgrm/fidelius

# 2. Bouncy Castle Custom Curve
# https://github.com/bcgit/bc-java/blob/main/core/src/main/java/org/bouncycastle/crypto/ec/CustomNamedCurves.java#L77

# 3. fastecdsa Resource
# pip install fastecdsa
# https://github.com/AntonKueltz/fastecdsa#id8

# 4. ABDM Guidelines
# https://sandbox.abdm.gov.in/abdm-docs/EncryptionAndDecryptionData

# Considerations for format of keys
# 1. Note the format that Java uses for integers in the curve is Big endian (https://en.wikipedia.org/wiki/Endianness)
# 2. Public keys exported in X509 format should also be supported
# 3. Java Fidelius CLI returns output as base64 string for all methods (key material, encrypt and decrypt) as per ABDM guidelines.

# TODO Generate Curve Parameters using reference from Bouncy Castle

# name = 'CustomCurve25519'
# p = None
# a = None
# b = None
# q = None
# gx = None
# gy = None
# oid = None

# Create Custom Curve
# from fastecdsa.curve import Curve
# curve = Curve(
#     name,  # (str): The name of the curve
#     p,  # (long): The value of p in the curve equation.
#     a,  # (long): The value of a in the curve equation.
#     b,  # (long): The value of b in the curve equation.
#     q,  # (long): The order of the base point of the curve.
#     gx,  # (long): The x coordinate of the base point of the curve.
#     gy,  # (long): The y coordinate of the base point of the curve.
#     oid  # (str): The object identifier of the curve (optional).


# Below is sample Interface that python util should support from the custom curve created in python

# For methods output, see corresponding function on fildelius_encryption_util for input and output params
# (Java Fidelius CLI returns output as base64 string for all methods)
class PythonCustomCurve25519:

    @staticmethod
    def get_key_material():
        from fidelius import KeyMaterial
        key_material = KeyMaterial.generate()
        return {
            "publicKey": key_material.public_key,
            "privateKey": key_material.private_key,
            "nonce": key_material.nonce,
            "x509PublicKey": key_material.x509_public_key,
        }

    @staticmethod
    def encrypt_data(encryption_params):
        from fidelius import CryptoController
        return CryptoController.encrypt(encryption_params)


    @staticmethod
    def decrypt_data(decryption_params):
        from fidelius import CryptoController
        return CryptoController.decrypt(decryption_params)