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Key Management Service:Getting started with Encryption SDK for Python

Last Updated:Jun 15, 2023

Encryption SDK is a client-side encryption library that is used with Key Management Service (KMS) to encrypt and decrypt data, and sign data and verify signatures. This topic describes how to use Encryption SDK for Python 3 to encrypt and decrypt data.

Background information

For more information about the sample code of Encryption SDK for Python, visit alibabacloud-encryption-sdk-python.

Note

The AccessKey pair of an Alibaba Cloud account has permissions on all API operations. Using the AccessKey pair to perform operations is a high-risk operation. We recommend that you use a RAM user to call API operations or perform routine O&M. We recommend that you do not save the AccessKey ID and AccessKey secret in your project code. Otherwise, the AccessKey pair may be leaked and the security of all resources within your account may be compromised.

In this example, the AccessKey pair is saved in ALIBABA_CLOUD_ACCESS_KEY_ID and ALIBABA_CLOUD_ACCESS_KEY_SECRET environment variables to implement identity authentication. For more information about how to configure authentication information, see Instantiate a client and configure a credential.

Install Encryption SDK on your on-premises machine

  1. Install Encryption SDK.

    git clone https://github.com/aliyun/alibabacloud-encryption-sdk-python.git
    cd alibabacloud-encryption-sdk-python
    python setup.py install
  2. Check the version of Encryption SDK.

    1. Run the following command to enter the Python environment:

      python
    2. Run the following command to check the version of Encryption SDK:

      import aliyun_encryption_sdk
      aliyun_encryption_sdk.__version__

      After you run the command, the version number '0.1.1' is displayed in the Python console.

Encrypt and decrypt data of the byte array type

# -*- coding: UTF-8 -*-
"""Example showing basic encryption and decryption."""

import base64
import os

from aliyun_encryption_sdk.cache.local import LocalDataKeyMaterialCache
from aliyun_encryption_sdk.ckm.cache import CachingCryptoKeyManager
from aliyun_encryption_sdk.client import AliyunCrypto
from aliyun_encryption_sdk.kms import AliyunConfig
from aliyun_encryption_sdk.provider.default import DefaultDataKeyProvider


def build_aliyun_crypto(cache=False):
    config = AliyunConfig(ACCESS_KEY_ID, ACCESS_KEY_SECRET)
    client = AliyunCrypto(config)
    if cache:
        client.crypto_key_manager = CachingCryptoKeyManager(LocalDataKeyMaterialCache(), 5)
    return client


def encrypt_sample():
    print("Plaintext: " + PLAIN_TEXT)
    provider = DefaultDataKeyProvider(AES_KEY_ARN)
    client = build_aliyun_crypto(False)
    cipher_text, enc_material = client.encrypt(provider, PLAIN_TEXT.encode("utf-8"), ENCRYPTION_CONTEXT)
    cipher_text_str = base64.standard_b64encode(cipher_text).decode("utf-8")
    print(u"Ciphertext: " + cipher_text_str)
    return cipher_text_str


def decrypt_sample(cipher_text):
    cipher_text_bytes = base64.standard_b64decode(cipher_text.encode("utf-8"))
    provider = DefaultDataKeyProvider(AES_KEY_ARN)
    client = build_aliyun_crypto(False)
    plain_text, dec_material = client.decrypt(provider, cipher_text_bytes)
    print(u"Decryption result: " + bytes.de code(plain_text))
    return plain_text


if __name__ == '__main__':
    PLAIN_TEXT = "some plaintext"
    ACCESS_KEY_ID = os.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID")
    ACCESS_KEY_SECRET = os.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET")
    AES_KEY_ARN = os.getenv("AES_KEY_ARN")
    ENCRYPTION_CONTEXT = {
        "this": "context",
        "can help you": "to confirm",
        "this data": "is your original data"
    }
    cipherText = encrypt_sample()
    decrypt_sample(cipherText)

Encrypt and decrypt data of the byte stream type

# -*- coding: UTF-8 -*-
"""Example showing basic encryption and decryption."""

import os

from aliyun_encryption_sdk.cache.local import LocalDataKeyMaterialCache
from aliyun_encryption_sdk.ckm.cache import CachingCryptoKeyManager
from aliyun_encryption_sdk.client import AliyunCrypto
from aliyun_encryption_sdk.kms import AliyunConfig
from aliyun_encryption_sdk.provider.default import DefaultDataKeyProvider


def build_aliyun_crypto(cache=False):
    config = AliyunConfig(ACCESS_KEY_ID, ACCESS_KEY_SECRET)
    client = AliyunCrypto(config)
    if cache:
        client.crypto_key_manager = CachingCryptoKeyManager(LocalDataKeyMaterialCache(), 5)
    return client


def file_stream_sample():
    origin_file_path = r"some_file"
    encrypted_file_path = r"enc_file"
    decrypted_file_path = r"dec_file"
    provider = DefaultDataKeyProvider(AES_KEY_ARN)
    client = build_aliyun_crypto()
    with open(origin_file_path, "rb") as f, open(encryped_file_path, "wb") as cipher_text:
        encrypted_stream, _ = client.encrypt_stream(provider, f)
        with encrypted_stream as stream:
            for content in stream:
                cipher_text.write(content)

    with open(encryped_file_path, "rb") as f, open(decrypted_file_path, "wb") as plain_text:
        decrypted_stream, _ = client.decrypt_stream(provider, f)
        with decrypted_stream as stream:
            for content in stream:
                plain_text.write(content)


if __name__ == '__main__':
    ACCESS_KEY_ID = os.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID")
    ACCESS_KEY_SECRET = os.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET")
    AES_KEY_ARN = os.getenv("AES_KEY_ARN")
    file_stream_sample()