releasetools: Add apex_utils.py.

The added `testdata/testkey_with_passwd.key` is generated with:

$ openssl pkcs8 -inform DER -in testdata/testkey_with_passwd.pk8 \
    -out testdata/testkey_with_passwd.key -passin pass:foo

Bug: 123716522
Test: python -m unittest test_apex_utils
Change-Id: I7b7f00178ecab35c3e41ecf4d10295fe9bf480ab
diff --git a/tools/releasetools/test_apex_utils.py b/tools/releasetools/test_apex_utils.py
new file mode 100644
index 0000000..2f8ee49
--- /dev/null
+++ b/tools/releasetools/test_apex_utils.py
@@ -0,0 +1,87 @@
+#
+# Copyright (C) 2019 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import os
+import os.path
+
+import apex_utils
+import common
+import test_utils
+
+
+class ApexUtilsTest(test_utils.ReleaseToolsTestCase):
+
+  # echo "foo" | sha256sum
+  SALT = 'b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b878ae4944c'
+
+  def setUp(self):
+    self.testdata_dir = test_utils.get_testdata_dir()
+    # The default payload signing key.
+    self.payload_key = os.path.join(self.testdata_dir, 'testkey.key')
+
+  @staticmethod
+  def _GetTestPayload():
+    payload_file = common.MakeTempFile(prefix='apex-', suffix='.img')
+    with open(payload_file, 'wb') as payload_fp:
+      payload_fp.write(os.urandom(8192))
+    return payload_file
+
+  def test_ParseApexPayloadInfo(self):
+    payload_file = self._GetTestPayload()
+    apex_utils.SignApexPayload(
+        payload_file, self.payload_key, 'testkey', 'SHA256_RSA2048', self.SALT)
+    payload_info = apex_utils.ParseApexPayloadInfo(payload_file)
+    self.assertEqual('SHA256_RSA2048', payload_info['Algorithm'])
+    self.assertEqual(self.SALT, payload_info['Salt'])
+    self.assertEqual('testkey', payload_info['apex.key'])
+
+  def test_SignApexPayload(self):
+    payload_file = self._GetTestPayload()
+    apex_utils.SignApexPayload(
+        payload_file, self.payload_key, 'testkey', 'SHA256_RSA2048', self.SALT)
+    apex_utils.VerifyApexPayload(payload_file, self.payload_key)
+
+  def test_SignApexPayload_withSignerHelper(self):
+    payload_file = self._GetTestPayload()
+    payload_signer_args = '--signing_helper_with_files {}'.format(
+        os.path.join(self.testdata_dir, 'signing_helper.sh'))
+    apex_utils.SignApexPayload(
+        payload_file,
+        self.payload_key,
+        'testkey', 'SHA256_RSA2048', self.SALT,
+        payload_signer_args)
+    apex_utils.VerifyApexPayload(payload_file, self.payload_key)
+
+  def test_SignApexPayload_invalidKey(self):
+    self.assertRaises(
+        apex_utils.ApexSigningError,
+        apex_utils.SignApexPayload,
+        self._GetTestPayload(),
+        os.path.join(self.testdata_dir, 'testkey.x509.pem'),
+        'testkey',
+        'SHA256_RSA2048',
+        self.SALT)
+
+  def test_VerifyApexPayload_wrongKey(self):
+    payload_file = self._GetTestPayload()
+    apex_utils.SignApexPayload(
+        payload_file, self.payload_key, 'testkey', 'SHA256_RSA2048', self.SALT)
+    apex_utils.VerifyApexPayload(payload_file, self.payload_key)
+    self.assertRaises(
+        apex_utils.ApexSigningError,
+        apex_utils.VerifyApexPayload,
+        payload_file,
+        os.path.join(self.testdata_dir, 'testkey_with_passwd.key'))