AWS STS 使用获取需要令牌的会话MFA令牌 AWS SDK

以下代码示例说明如何获取需要令牌的会话令MFA牌。

警告

为避免安全风险，在开发专用软件或处理真实数据时，请勿使用IAM用户进行身份验证。而是使用与身份提供商的联合身份验证，例如 AWS IAM Identity Center。

• 创建一个IAM角色以授予列出 Amazon S3 存储桶的权限。

• 创建仅在提供MFA凭证后才有权担任该角色的IAM用户。

• 为用户注册MFA设备。

• 提供MFA凭证以获取会话令牌并使用临时证书列出 S3 存储桶。

Python

SDK适用于 Python (Boto3)

注意

还有更多相关信息 GitHub。查找完整示例，学习如何在 AWS 代码示例存储库中进行设置和运行。

创建IAM用户、注册MFA设备并创建一个角色，该角色授予允许用户仅在使用MFA凭据时列出 S3 存储桶的权限。

def setup(iam_resource):
    """
    Creates a new user with no permissions.
    Creates a new virtual multi-factor authentication (MFA) device.
    Displays the QR code to seed the device.
    Asks for two codes from the MFA device.
    Registers the MFA device for the user.
    Creates an access key pair for the user.
    Creates an inline policy for the user that lets the user list Amazon S3 buckets,
    but only when MFA credentials are used.

    Any MFA device that can scan a QR code will work with this demonstration.
    Common choices are mobile apps like LastPass Authenticator,
    Microsoft Authenticator, or Google Authenticator.

    :param iam_resource: A Boto3 AWS Identity and Access Management (IAM) resource
                         that has permissions to create users, MFA devices, and
                         policies in the account.
    :return: The newly created user, user key, and virtual MFA device.
    """
    user = iam_resource.create_user(UserName=unique_name("user"))
    print(f"Created user {user.name}.")

    virtual_mfa_device = iam_resource.create_virtual_mfa_device(
        VirtualMFADeviceName=unique_name("mfa")
    )
    print(f"Created virtual MFA device {virtual_mfa_device.serial_number}")

    print(
        f"Showing the QR code for the device. Scan this in the MFA app of your "
        f"choice."
    )
    with open("qr.png", "wb") as qr_file:
        qr_file.write(virtual_mfa_device.qr_code_png)
    webbrowser.open(qr_file.name)

    print(f"Enter two consecutive code from your MFA device.")
    mfa_code_1 = input("Enter the first code: ")
    mfa_code_2 = input("Enter the second code: ")
    user.enable_mfa(
        SerialNumber=virtual_mfa_device.serial_number,
        AuthenticationCode1=mfa_code_1,
        AuthenticationCode2=mfa_code_2,
    )
    os.remove(qr_file.name)
    print(f"MFA device is registered with the user.")

    user_key = user.create_access_key_pair()
    print(f"Created access key pair for user.")

    print(f"Wait for user to be ready.", end="")
    progress_bar(10)

    user.create_policy(
        PolicyName=unique_name("user-policy"),
        PolicyDocument=json.dumps(
            {
                "Version": "2012-10-17",
                "Statement": [
                    {
                        "Effect": "Allow",
                        "Action": "s3:ListAllMyBuckets",
                        "Resource": "arn:aws:s3:::*",
                        "Condition": {"Bool": {"aws:MultiFactorAuthPresent": True}},
                    }
                ],
            }
        ),
    )
    print(
        f"Created an inline policy for {user.name} that lets the user list buckets, "
        f"but only when MFA credentials are present."
    )

    print("Give AWS time to propagate these new resources and connections.", end="")
    progress_bar(10)

    return user, user_key, virtual_mfa_device

通过传递MFA令牌来获取临时会话证书，然后使用这些证书列出账户的 S3 存储桶。

def list_buckets_with_session_token_with_mfa(mfa_serial_number, mfa_totp, sts_client):
    """
    Gets a session token with MFA credentials and uses the temporary session
    credentials to list Amazon S3 buckets.

    Requires an MFA device serial number and token.

    :param mfa_serial_number: The serial number of the MFA device. For a virtual MFA
                              device, this is an Amazon Resource Name (ARN).
    :param mfa_totp: A time-based, one-time password issued by the MFA device.
    :param sts_client: A Boto3 STS instance that has permission to assume the role.
    """
    if mfa_serial_number is not None:
        response = sts_client.get_session_token(
            SerialNumber=mfa_serial_number, TokenCode=mfa_totp
        )
    else:
        response = sts_client.get_session_token()
    temp_credentials = response["Credentials"]

    s3_resource = boto3.resource(
        "s3",
        aws_access_key_id=temp_credentials["AccessKeyId"],
        aws_secret_access_key=temp_credentials["SecretAccessKey"],
        aws_session_token=temp_credentials["SessionToken"],
    )

    print(f"Buckets for the account:")
    for bucket in s3_resource.buckets.all():
        print(bucket.name)

销毁为演示创建的资源。

def teardown(user, virtual_mfa_device):
    """
    Removes all resources created during setup.

    :param user: The demo user.
    :param role: The demo MFA device.
    """
    for user_pol in user.policies.all():
        user_pol.delete()
        print("Deleted inline user policy.")
    for key in user.access_keys.all():
        key.delete()
        print("Deleted user's access key.")
    for mfa in user.mfa_devices.all():
        mfa.disassociate()
    virtual_mfa_device.delete()
    user.delete()
    print(f"Deleted {user.name}.")

使用之前定义的函数运行此方案。

def usage_demo():
    """Drives the demonstration."""
    print("-" * 88)
    print(
        f"Welcome to the AWS Security Token Service assume role demo, "
        f"starring multi-factor authentication (MFA)!"
    )
    print("-" * 88)
    iam_resource = boto3.resource("iam")
    user, user_key, virtual_mfa_device = setup(iam_resource)
    try:
        sts_client = boto3.client(
            "sts", aws_access_key_id=user_key.id, aws_secret_access_key=user_key.secret
        )
        try:
            print("Listing buckets without specifying MFA credentials.")
            list_buckets_with_session_token_with_mfa(None, None, sts_client)
        except ClientError as error:
            if error.response["Error"]["Code"] == "AccessDenied":
                print("Got expected AccessDenied error.")
        mfa_totp = input("Enter the code from your registered MFA device: ")
        list_buckets_with_session_token_with_mfa(
            virtual_mfa_device.serial_number, mfa_totp, sts_client
        )
    finally:
        teardown(user, virtual_mfa_device)
        print("Thanks for watching!")

• 有关API详细信息，请参阅GetSessionToken中的 AWS SDKPython (Boto3) API 参考。