Generate Google Pay private/public keys

generate-google-pay-keys.py

"""
Generate private/public keys for use in Google Pay Business Console
https://pay.google.com/business/console/
"""

import base64
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives import serialization

# Generate the ECDSA private key
private_key = ec.generate_private_key(ec.SECP256R1())

# Get the public key
public_key = private_key.public_key()

# Serialize the public key in uncompressed point format
uncompressed_public_key = public_key.public_bytes(
    encoding=serialization.Encoding.X962,
    format=serialization.PublicFormat.UncompressedPoint
)

# Print the length of the public key to ensure it is 88 bytes
print(f"Uncompressed Public Key Length: {len(uncompressed_public_key)} bytes")
print(f"Uncompressed Public Key: {uncompressed_public_key.hex()}")

# Convert the uncompressed public key to base64 format
base64_public_key = base64.b64encode(uncompressed_public_key).decode("utf-8")
print(f"Base64 Public Key: {base64_public_key}")

with open("base64_public_key.txt", "wb") as key_file:
    key_file.write(base64_public_key.encode("utf-8"))
    print("Public key saved in base64 format to base64_public_key.txt")

# Serialize the private key to PEM format and save it to a file
pem_private_key = private_key.private_bytes(
    encoding=serialization.Encoding.PEM,
    format=serialization.PrivateFormat.PKCS8,
    encryption_algorithm=serialization.NoEncryption()  # No encryption for simplicity
)

# Write the PEM private key to a file
with open("ecdsa_private_key.pem", "wb") as key_file:
    key_file.write(pem_private_key)
    print("Private key saved to ecdsa_private_key.pem")