How to use GCP Cloud KSM to encrypt data

gcp_cloud_ksm_encrypt.py

# https://cloud.google.com/kms/docs/encrypt-decrypt

# Import base64 for printing the ciphertext.
import base64

# Import the client library.
from google.cloud import kms


def encrypt_symmetric(
    project_id: str, location_id: str, key_ring_id: str, key_id: str, plaintext: str
) -> bytes:
    """
    Encrypt plaintext using a symmetric key.

    Args:
        project_id (string): Google Cloud project ID (e.g. 'my-project').
        location_id (string): Cloud KMS location (e.g. 'us-east1').
        key_ring_id (string): ID of the Cloud KMS key ring (e.g. 'my-key-ring').
        key_id (string): ID of the key to use (e.g. 'my-key').
        plaintext (string): message to encrypt

    Returns:
        bytes: Encrypted ciphertext.

    """

    # Convert the plaintext to bytes.
    plaintext_bytes = plaintext.encode("utf-8")

    # Optional, but recommended: compute plaintext's CRC32C.
    # See crc32c() function defined below.
    plaintext_crc32c = crc32c(plaintext_bytes)

    # Create the client.
    client = kms.KeyManagementServiceClient()

    # Build the key name.
    key_name = client.crypto_key_path(project_id, location_id, key_ring_id, key_id)

    # Call the API.
    encrypt_response = client.encrypt(
        request={
            "name": key_name,
            "plaintext": plaintext_bytes,
            "plaintext_crc32c": plaintext_crc32c,
        }
    )

    # Optional, but recommended: perform integrity verification on encrypt_response.
    # For more details on ensuring E2E in-transit integrity to and from Cloud KMS visit:
    # https://cloud.google.com/kms/docs/data-integrity-guidelines
    if not encrypt_response.verified_plaintext_crc32c:
        raise Exception("The request sent to the server was corrupted in-transit.")
    if not encrypt_response.ciphertext_crc32c == crc32c(encrypt_response.ciphertext):
        raise Exception(
            "The response received from the server was corrupted in-transit."
        )
    # End integrity verification

    print(f"Ciphertext: {base64.b64encode(encrypt_response.ciphertext)}")
    return encrypt_response


def crc32c(data: bytes) -> int:
    """
    Calculates the CRC32C checksum of the provided data.

    Args:
        data: the bytes over which the checksum should be calculated.

    Returns:
        An int representing the CRC32C checksum of the provided bytes.
    """
    import crcmod  # type: ignore

    crc32c_fun = crcmod.predefined.mkPredefinedCrcFun("crc-32c")
    return crc32c_fun(data)


encrypt_symmetric(
    project_id="xxx",
    location_id="me-central2",
    key_ring_id="xxx-keyring",
    key_id="xx-key",
    plaintext="MyStrongPassWord",
)

# out put base64
'CiQAs2q1BAfJeEuZGOZ1jJV3ATvVDj5k9we3KbnTqLraYVkup/4SewDK05J2+IXIIq1PXGc66IMugBTad1NtPTEe3EyBjZidubeMOfDqU5D3KbnTqLraYVkup/4SewDK0HyoPNGISXF3zaDd14DstDg+DhonX0zjF6KBeIw/EIrRXl6h76V2izGmL3rp+Lwg9hW'