Question

我尝试使用带有AWS KMS的python 3.6和boto3进行加密演示，但它缺少AES的操作模式。我想知道您是否可以指出我的操作方向。

我试图在KeySpec的调用中定义AES.CBC_MODE，但是它只使用AES_256或AES_128。

代码如下：

import base64
import boto3

from Crypto.Cipher import AES


PAD = lambda s: s + (32 - len(s) % 32) * ' '


def get_arn(aws_data):
    return 'arn:aws:kms:{region}:{account_number}:key/{key_id}'.format(**aws_data)


def encrypt_data(aws_data, plaintext_message):
    kms_client = boto3.client(
        'kms',
        region_name=aws_data['region'],
        aws_access_key_id='your_key_id',
        aws_secret_access_key='your_secred_key_id')

    data_key = kms_client.generate_data_key(
        KeyId=aws_data['key_id'],
        KeySpec='AES_256')

    cipher_text_blob = data_key.get('CiphertextBlob')
    plaintext_key = data_key.get('Plaintext')

    # Note, does not use IV or specify mode... for demo purposes only.
    cypher = AES.new(plaintext_key, AES.MODE_CBC)
    encrypted_data = base64.b64encode(cypher.encrypt(PAD(plaintext_message)))

    # Need to preserve both of these data elements
    return encrypted_data, cipher_text_blob


def decrypt_data(aws_data, encrypted_data, cipher_text_blob):
    kms_client = boto3.client(
        'kms',
        region_name=aws_data['region'])

    decrypted_key = kms_client.decrypt(CiphertextBlob=cipher_text_blob).get('Plaintext')
    cypher = AES.new(decrypted_key)

    return cypher.decrypt(base64.b64decode(encrypted_data)).rstrip()


def main():
    # Add your account number / region / KMS Key ID here.
    aws_data = {
        'region': 'us-east-1',
        'account_number': 'your_account',
        'key_id': 'your_key_id',
    }

    # And your super secret message to envelope encrypt...
    plaintext = 'Superduper and the mighty Scoop!'

    # Store encrypted_data & cipher_text_blob in your persistent storage. You will need them both later.
    encrypted_data, cipher_text_blob = encrypt_data(aws_data, plaintext)
    print(encrypted_data)

    # # Later on when you need to decrypt, get these from your persistent storage.
    decrypted_data = decrypt_data(aws_data, encrypted_data, cipher_text_blob)
    print(decrypted_data)

if __name__ == '__main__':
    main()

Answer 1

您是否考虑过使用AWS Encryption SDK，而不是自己实现信封加密？[1] [2]它与AWS KMS紧密集成，并且使安全信封加密变得简单，使用KMS CMK保护您的数据密钥。通过向您返回一条包含用户需要知道的所有信息的密文消息，它可以使跟踪解密所需的所有片段（IV，加密的数据密钥，加密上下文等）变得很简单。消息。

您可以在此处找到有关如何实现与您的问题类似的示例[3]。

[1] https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/introduction.html

[2] https://aws-encryption-sdk-python.readthedocs.io/en/latest/

[3] https://github.com/aws/aws-encryption-sdk-python/blob/master/examples/src/basic_encryption.py

Answer 2

AES_128和AES_256是指AES 128位/ AES 256位加密密钥。

CBC表示密码块链接

GCM表示伽罗瓦/计数器模式

KMS使用AES_256和GCM。不支持CBC。

AWS KMS在其中使用高级加密标准（AES）算法 Galois /计数器模式（GCM），称为AES-GCM。 AWS KMS使用此具有256位秘密密钥的算法。

带有AES CBC的AWS KMS python3.6和boto3示例

2 个答案: