docs(samples): add checksum snippets (#255)

* docs(samples): add checksum snippets

Source-Link: googleapis/synthtool@571ee2c
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:660abdf857d3ab9aabcd967c163c70e657fcc5653595c709263af5f3fa23ef67

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* lint

* lint

* lint

* remove extra blank line

* lint

* Fix  `google-crc32c` pin in samples/snippets/requirements.txt

Co-authored-by: gcf-owl-bot[bot] <78513119+gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Anthonios Partheniou <[email protected]>

Author: 3 people

secretmanager/snippets/access_secret_version.py

@@ -18,6 +18,8 @@
 
 import argparse
 
+import google_crc32c
+
 
 # [START secretmanager_access_secret_version]
 def access_secret_version(project_id, secret_id, version_id):
@@ -38,6 +40,13 @@ def access_secret_version(project_id, secret_id, version_id):
     # Access the secret version.
     response = client.access_secret_version(request={"name": name})
 
+    # Verify payload checksum.
+    crc32c = google_crc32c.Checksum()
+    crc32c.update(response.payload.data)
+    if response.payload.data_crc32c != int(crc32c.hexdigest(), 16):
+        print("Data corruption detected.")
+        return response
+
     # Print the secret payload.
     #
     # WARNING: Do not print the secret in a production environment - this

secretmanager/snippets/add_secret_version.py

@@ -19,6 +19,8 @@
 
 import argparse
 
+import google_crc32c
+
 
 # [START secretmanager_add_secret_version]
 def add_secret_version(project_id, secret_id, payload):
@@ -39,9 +41,17 @@ def add_secret_version(project_id, secret_id, payload):
     # pass in bytes instead of a str for the payload argument.
     payload = payload.encode("UTF-8")
 
+    # Calculate payload checksum. Passing a checksum in add-version request
+    # is optional.
+    crc32c = google_crc32c.Checksum()
+    crc32c.update(payload)
+
     # Add the secret version.
     response = client.add_secret_version(
-        request={"parent": parent, "payload": {"data": payload}}
+        request={
+            "parent": parent,
+            "payload": {"data": payload, "data_crc32c": int(crc32c.hexdigest(), 16)},
+        }
     )
 
     # Print the new secret version name.

secretmanager/snippets/requirements.txt

@@ -1 +1,2 @@
-google-cloud-secret-manager==2.9.1
+google-cloud-secret-manager==2.9.1
+google-crc32c==1.3.0