WIP chore(python): simple example for encrypted table

Author: imabhichow

Examples/runtimes/python/DynamoDBEncryption/src/keyring/hierarchical_keyring/__init__.py

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+# Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+"""Stub to allow relative imports of examples from tests."""

Examples/runtimes/python/DynamoDBEncryption/src/keyring/hierarchical_keyring/with_encrypted_client.py

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+# Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+"""
+Example demonstrating DynamoDb Encryption using a Hierarchical Keyring with EncryptedClient.
+
+This example sets up DynamoDb Encryption for the AWS SDK client
+using the Hierarchical Keyring, which establishes a key hierarchy
+where "branch" keys are persisted in DynamoDb.
+These branch keys are used to protect your data keys,
+and these branch keys are themselves protected by a root KMS Key.
+
+Running this example requires access to the DDB Table whose name
+is provided in CLI arguments.
+This table must be configured with the following
+primary key configuration:
+  - Partition key is named "partition_key" with type (S)
+  - Sort key is named "sort_key" with type (S)
+
+This example also requires using a KMS Key whose ARN
+is provided in CLI arguments. You need the following access
+on this key:
+  - GenerateDataKeyWithoutPlaintext
+  - Decrypt
+"""
+
+import boto3
+from aws_cryptographic_material_providers.keystore.client import KeyStore
+from aws_cryptographic_material_providers.keystore.config import KeyStoreConfig
+from aws_cryptographic_material_providers.keystore.models import KMSConfigurationKmsKeyArn
+from aws_cryptographic_material_providers.mpl import AwsCryptographicMaterialProviders
+from aws_cryptographic_material_providers.mpl.config import MaterialProvidersConfig
+from aws_cryptographic_material_providers.mpl.models import (
+    CacheTypeDefault,
+    CreateAwsKmsHierarchicalKeyringInput,
+    DefaultCache,
+)
+from aws_dbesdk_dynamodb.encrypted.client import EncryptedClient
+from aws_dbesdk_dynamodb.smithygenerated.aws_cryptography_dbencryptionsdk_dynamodb.client import DynamoDbEncryption
+from aws_dbesdk_dynamodb.smithygenerated.aws_cryptography_dbencryptionsdk_dynamodb.config import (
+    DynamoDbEncryptionConfig,
+)
+from aws_dbesdk_dynamodb.structures.dynamodb import (
+    CreateDynamoDbEncryptionBranchKeyIdSupplierInput,
+    DynamoDbTableEncryptionConfig,
+    DynamoDbTablesEncryptionConfig,
+)
+from aws_dbesdk_dynamodb.structures.structured_encryption import (
+    CryptoAction,
+)
+
+from ..example_branch_key_id_supplier import ExampleBranchKeyIdSupplier
+
+
+def hierarchical_keyring_client_example(
+    ddb_table_name: str,
+    tenant1_branch_key_id: str,
+    tenant2_branch_key_id: str,
+    keystore_table_name: str,
+    logical_keystore_name: str,
+    kms_key_id: str,
+):
+    """
+    Demonstrate using a hierarchical keyring with multiple tenants using EncryptedClient.
+
+    :param ddb_table_name: The name of the DynamoDB table
+    :param tenant1_branch_key_id: Branch key ID for tenant 1
+    :param tenant2_branch_key_id: Branch key ID for tenant 2
+    :param keystore_table_name: The name of the KeyStore DynamoDB table
+    :param logical_keystore_name: The logical name for this keystore
+    :param kms_key_id: The ARN of the KMS key to use
+    """
+    # Initial KeyStore Setup: This example requires that you have already
+    # created your KeyStore, and have populated it with two new branch keys.
+    # See the "Create KeyStore Table Example" and "Create KeyStore Key Example"
+    # for an example of how to do this.
+
+    # 1. Configure your KeyStore resource.
+    #    This SHOULD be the same configuration that you used
+    #    to initially create and populate your KeyStore.
+    keystore = KeyStore(
+        config=KeyStoreConfig(
+            ddb_client=boto3.client("dynamodb"),
+            ddb_table_name=keystore_table_name,
+            logical_key_store_name=logical_keystore_name,
+            kms_client=boto3.client("kms"),
+            kms_configuration=KMSConfigurationKmsKeyArn(kms_key_id),
+        )
+    )
+
+    # 2. Create a Branch Key ID Supplier. See ExampleBranchKeyIdSupplier in this directory.
+    ddb_enc = DynamoDbEncryption(config=DynamoDbEncryptionConfig())
+    branch_key_id_supplier = ddb_enc.create_dynamo_db_encryption_branch_key_id_supplier(
+        input=CreateDynamoDbEncryptionBranchKeyIdSupplierInput(
+            ddb_key_branch_key_id_supplier=ExampleBranchKeyIdSupplier(tenant1_branch_key_id, tenant2_branch_key_id)
+        )
+    ).branch_key_id_supplier
+
+    # 3. Create the Hierarchical Keyring, using the Branch Key ID Supplier above.
+    #    With this configuration, the AWS SDK Client ultimately configured will be capable
+    #    of encrypting or decrypting items for either tenant (assuming correct KMS access).
+    #    If you want to restrict the client to only encrypt or decrypt for a single tenant,
+    #    configure this Hierarchical Keyring using `.branch_key_id=tenant1_branch_key_id` instead
+    #    of `.branch_key_id_supplier=branch_key_id_supplier`.
+    mat_prov = AwsCryptographicMaterialProviders(config=MaterialProvidersConfig())
+
+    keyring_input = CreateAwsKmsHierarchicalKeyringInput(
+        key_store=keystore,
+        branch_key_id_supplier=branch_key_id_supplier,
+        ttl_seconds=600,  # This dictates how often we call back to KMS to authorize use of the branch keys
+        cache=CacheTypeDefault(  # This dictates how many branch keys will be held locally
+            value=DefaultCache(entry_capacity=100)
+        ),
+    )
+
+    hierarchical_keyring = mat_prov.create_aws_kms_hierarchical_keyring(input=keyring_input)
+
+    # 4. Configure which attributes are encrypted and/or signed when writing new items.
+    #    For each attribute that may exist on the items we plan to write to our DynamoDbTable,
+    #    we must explicitly configure how they should be treated during item encryption:
+    #      - ENCRYPT_AND_SIGN: The attribute is encrypted and included in the signature
+    #      - SIGN_ONLY: The attribute not encrypted, but is still included in the signature
+    #      - DO_NOTHING: The attribute is not encrypted and not included in the signature
+    attribute_actions = {
+        "partition_key": CryptoAction.SIGN_ONLY,  # Our partition attribute must be SIGN_ONLY
+        "sort_key": CryptoAction.SIGN_ONLY,  # Our sort attribute must be SIGN_ONLY
+        "tenant_sensitive_data": CryptoAction.ENCRYPT_AND_SIGN,
+    }
+
+    # 5. Configure which attributes we expect to be included in the signature
+    #    when reading items. There are two options for configuring this:
+    #
+    #    - (Recommended) Configure `allowed_unsigned_attribute_prefix`:
+    #      When defining your DynamoDb schema and deciding on attribute names,
+    #      choose a distinguishing prefix (such as ":") for all attributes that
+    #      you do not want to include in the signature.
+    #      This has two main benefits:
+    #      - It is easier to reason about the security and authenticity of data within your item
+    #        when all unauthenticated data is easily distinguishable by their attribute name.
+    #      - If you need to add new unauthenticated attributes in the future,
+    #        you can easily make the corresponding update to your `attribute_actions`
+    #        and immediately start writing to that new attribute, without
+    #        any other configuration update needed.
+    #      Once you configure this field, it is not safe to update it.
+    #
+    #    - Configure `allowed_unsigned_attributes`: You may also explicitly list
+    #      a set of attributes that should be considered unauthenticated when encountered
+    #      on read. Be careful if you use this configuration. Do not remove an attribute
+    #      name from this configuration, even if you are no longer writing with that attribute,
+    #      as old items may still include this attribute, and our configuration needs to know
+    #      to continue to exclude this attribute from the signature scope.
+    #      If you add new attribute names to this field, you must first deploy the update to this
+    #      field to all readers in your host fleet before deploying the update to start writing
+    #      with that new attribute.
+    #
+    #   For this example, we currently authenticate all attributes. To make it easier to
+    #   add unauthenticated attributes in the future, we define a prefix ":" for such attributes.
+    unsign_attr_prefix = ":"
+
+    # 6. Create the DynamoDb Encryption configuration for the table we will be writing to.
+    table_config = DynamoDbTableEncryptionConfig(
+        logical_table_name=ddb_table_name,
+        partition_key_name="partition_key",
+        sort_key_name="sort_key",
+        attribute_actions_on_encrypt=attribute_actions,
+        keyring=hierarchical_keyring,
+        allowed_unsigned_attribute_prefix=unsign_attr_prefix,
+    )
+
+    table_configs = {ddb_table_name: table_config}
+    tables_config = DynamoDbTablesEncryptionConfig(table_encryption_configs=table_configs)
+
+    # 7. Create the EncryptedClient
+    ddb_client = boto3.client("dynamodb")
+    encrypted_ddb_client = EncryptedClient(client=ddb_client, encryption_config=tables_config)
+
+    # 8. Put an item into our table using the above client.
+    #    Before the item gets sent to DynamoDb, it will be encrypted
+    #    client-side, according to our configuration.
+    #    Because the item we are writing uses "tenantId1" as our partition value,
+    #    based on the code we wrote in the ExampleBranchKeySupplier,
+    #    `tenant1_branch_key_id` will be used to encrypt this item.
+    item = {
+        "partition_key": {"S": "tenant1Id"},
+        "sort_key": {"N": "0"},
+        "tenant_sensitive_data": {"S": "encrypt and sign me!"},
+    }
+
+    put_response = encrypted_ddb_client.put_item(TableName=ddb_table_name, Item=item)
+
+    # Demonstrate that PutItem succeeded
+    assert put_response["ResponseMetadata"]["HTTPStatusCode"] == 200
+
+    # 9. Get the item back from our table using the same client.
+    #    The client will decrypt the item client-side, and return
+    #    back the original item.
+    #    Because the returned item's partition value is "tenantId1",
+    #    based on the code we wrote in the ExampleBranchKeySupplier,
+    #    `tenant1_branch_key_id` will be used to decrypt this item.
+    key_to_get = {"partition_key": {"S": "tenant1Id"}, "sort_key": {"N": "0"}}
+
+    get_response = encrypted_ddb_client.get_item(TableName=ddb_table_name, Key=key_to_get)
+
+    # Demonstrate that GetItem succeeded and returned the decrypted item
+    assert get_response["ResponseMetadata"]["HTTPStatusCode"] == 200
+    returned_item = get_response["Item"]
+    assert returned_item["tenant_sensitive_data"]["S"] == "encrypt and sign me!"