docs: change examples to talk about "KMS discovery keyring" rather than "KMS keyring in discovery mode"

Author: mattsb42-aws

examples/src/keyring/aws_kms/discovery_decrypt.py

@@ -5,8 +5,8 @@
 This is true both on encrypt and on decrypt.
 However, sometimes you need more flexibility on decrypt,
 especially if you might not know beforehand which CMK was used to encrypt a message.
-To address this need, the KMS keyring also supports "discovery" mode.
-In discovery mode, the KMS keyring will do nothing on encrypt
+To address this need, you can use a KMS discovery keyring.
+The KMS discovery keyring will do nothing on encrypt
 but will attempt to decrypt *any* data keys that were encrypted under a KMS CMK.
 
 This example shows how to configure and use a KMS keyring in discovery mode.

examples/src/keyring/aws_kms/discovery_decrypt_in_region_only.py

@@ -5,14 +5,14 @@
 This is true both on encrypt and on decrypt.
 However, sometimes you need more flexibility on decrypt,
 especially if you might not know beforehand which CMK was used to encrypt a message.
-To address this need, the KMS keyring also supports "discovery" mode.
-In discovery mode, the KMS keyring will do nothing on encrypt
+To address this need, you can use a KMS discovery keyring.
+The KMS discovery keyring will do nothing on encrypt
 but will attempt to decrypt *any* data keys that were encrypted under a KMS CMK.
 
 However, sometimes you need to be a *bit* more restrictive than that.
 To address this need, you can use a client supplier to restrict what regions a KMS keyring can talk to.
 
-This example shows how to configure and use a KMS keyring in discovery mode that is restricted to one region.
+This example shows how to configure and use a KMS regional discovery keyring that is restricted to one region.
 
 https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/choose-keyring.html#use-kms-keyring
 
@@ -23,7 +23,7 @@
 see the ``keyring/aws_kms/custom_client_supplier``
 and ``keyring/aws_kms/custom_kms_client_config`` examples.
 
-For examples of how to use the KMS keyring in discovery mode on decrypt,
+For examples of how to use the KMS discovery keyring on decrypt,
 see the ``keyring/aws_kms/discovery_decrypt``
 and ``keyring/aws_kms/discovery_decrypt_with_preferred_region`` examples.
 """

examples/src/keyring/aws_kms/discovery_decrypt_with_preferred_regions.py

@@ -5,8 +5,8 @@
 This is true both on encrypt and on decrypt.
 However, sometimes you need more flexibility on decrypt,
 especially if you might not know beforehand which CMK was used to encrypt a message.
-To address this need, the KMS keyring also supports "discovery" mode.
-In discovery mode, the KMS keyring will do nothing on encrypt
+To address this need, you can use a KMS discovery keyring.
+The KMS discovery keyring will do nothing on encrypt
 but will attempt to decrypt *any* data keys that were encrypted under a KMS CMK.
 
 However, sometimes you need to be a *bit* more restrictive than that.
@@ -29,7 +29,7 @@
 see the ``keyring/aws_kms/custom_client_supplier``
 and ``keyring/aws_kms/custom_kms_client_config`` examples.
 
-For examples of how to use the KMS keyring in discovery mode on decrypt,
+For examples of how to use the KMS discovery keyring on decrypt,
 see the ``keyring/aws_kms/discovery_decrypt``
 and ``keyring/aws_kms/discovery_decrypt_in_region_only`` examples.
 """
@@ -64,8 +64,7 @@ def run(aws_kms_cmk, source_plaintext):
     # To create our decrypt keyring, we need to know our current default AWS region.
     #
     # Create a throw-away boto3 session to discover the default region.
-    boto3_session = Session()
-    local_region = boto3_session.region_name
+    local_region = Session().region_name
 
     # Now, use that region name to create two KMS discovery keyrings:
     #
@@ -78,7 +77,7 @@ def run(aws_kms_cmk, source_plaintext):
 
     # Finally, combine those two keyrings into a multi-keyring.
     #
-    # The multi-keyring steps through its member keyrings in the order that you provider them,
+    # The multi-keyring steps through its member keyrings in the order that you provide them,
     # attempting to decrypt every encrypted data key with each keyring before moving on to the next keyring.
     # Because of this, other_regions_decrypt_keyring will not be called
     # unless local_region_decrypt_keyring fails to decrypt every encrypted data key.
@@ -92,7 +91,7 @@ def run(aws_kms_cmk, source_plaintext):
     # Demonstrate that the ciphertext and plaintext are different.
     assert ciphertext != source_plaintext
 
-    # Decrypt your encrypted data using the KMS discovery keyring.
+    # Decrypt your encrypted data using the multi-keyring.
     #
     # We do not need to specify the encryption context on decrypt
     # because the header message includes the encryption context.