cli: Always write utf-8

Apparently Python really likes to use cp1252 on some platforms but our
bundles must not be platform specific.

Signed-off-by: Jussi Kukkonen <[email protected]>

Author: jku

sigstore/_cli.py

@@ -686,16 +686,16 @@ def _sign_file_threaded(
 
     if outputs.signature is not None:
         signature = base64.b64encode(result.signature).decode()
-        with outputs.signature.open(mode="w") as io:
+        with outputs.signature.open(mode="w", encoding="utf-8") as io:
             print(signature, file=io)
 
     if outputs.certificate is not None:
         cert_pem = signer._signing_cert().public_bytes(Encoding.PEM).decode()
-        with outputs.certificate.open(mode="w") as io:
+        with outputs.certificate.open(mode="w", encoding="utf-8") as io:
             print(cert_pem, file=io)
 
     if outputs.bundle is not None:
-        with outputs.bundle.open(mode="w") as io:
+        with outputs.bundle.open(mode="w", encoding="utf-8") as io:
             print(result.to_json(), file=io)
 
 
@@ -769,7 +769,7 @@ def _attest(args: argparse.Namespace) -> None:
         _invalid_arguments(args, f"Predicate must be a file: {predicate_path}")
 
     try:
-        with open(predicate_path, "r") as f:
+        with open(predicate_path, "r", encoding="utf-8") as f:
             predicate = json.load(f)
             # We do a basic sanity check using our Pydantic models to see if the
             # contents of the predicate file match the specified predicate type.

test/integration/cli/test_attest.py

@@ -73,7 +73,7 @@ def test_attest_success_default_output_bundle(
 
     assert expected_output_bundle.exists()
     verifier = Verifier.staging()
-    with open(expected_output_bundle, "r") as bundle_file:
+    with open(expected_output_bundle, "r", encoding="utf-8") as bundle_file:
         bundle = Bundle.from_json(bundle_file.read())
         verifier.verify_dsse(bundle=bundle, policy=UnsafeNoOp())
 

test/integration/cli/test_sign.py

@@ -72,7 +72,7 @@ def test_sign_success_default_output_bundle(
     assert expected_output_bundle.exists()
     verifier = Verifier.staging()
     with (
-        open(expected_output_bundle, "r") as bundle_file,
+        open(expected_output_bundle, "r", encoding="utf-8") as bundle_file,
         open(artifact, "rb") as input_file,
     ):
         bundle = Bundle.from_json(bundle_file.read())
@@ -112,7 +112,7 @@ def test_sign_success_multiple_artifacts(capsys, sigstore, asset_integration, tm
         assert expected_output_bundle.exists()
         verifier = Verifier.staging()
         with (
-            open(expected_output_bundle, "r") as bundle_file,
+            open(expected_output_bundle, "r", encoding="utf-8") as bundle_file,
             open(artifact, "rb") as input_file,
         ):
             bundle = Bundle.from_json(bundle_file.read())
@@ -154,7 +154,7 @@ def test_sign_success_multiple_artifacts_rekor_v2(
         assert expected_output_bundle.exists()
         verifier = Verifier.staging()
         with (
-            open(expected_output_bundle, "r") as bundle_file,
+            open(expected_output_bundle, "r", encoding="utf-8") as bundle_file,
             open(artifact, "rb") as input_file,
         ):
             bundle = Bundle.from_json(bundle_file.read())