diff --git a/tools/releasetools/apex_utils.py b/tools/releasetools/apex_utils.py
new file mode 100644
index 0000000..d14c94f
--- /dev/null
+++ b/tools/releasetools/apex_utils.py
@@ -0,0 +1,147 @@
+#!/usr/bin/env python
+#
+# 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 logging
+import os.path
+import re
+import shlex
+import sys
+
+import common
+
+logger = logging.getLogger(__name__)
+
+
+class ApexInfoError(Exception):
+  """An Exception raised during Apex Information command."""
+
+  def __init__(self, message):
+    Exception.__init__(self, message)
+
+
+class ApexSigningError(Exception):
+  """An Exception raised during Apex Payload signing."""
+
+  def __init__(self, message):
+    Exception.__init__(self, message)
+
+
+def SignApexPayload(payload_file, payload_key_path, payload_key_name, algorithm,
+                    salt, signing_args=None):
+  """Signs a given payload_file with the payload key."""
+  # Add the new footer. Old footer, if any, will be replaced by avbtool.
+  cmd = ['avbtool', 'add_hashtree_footer',
+         '--do_not_generate_fec',
+         '--algorithm', algorithm,
+         '--key', payload_key_path,
+         '--prop', 'apex.key:{}'.format(payload_key_name),
+         '--image', payload_file,
+         '--salt', salt]
+  if signing_args:
+    cmd.extend(shlex.split(signing_args))
+
+  try:
+    common.RunAndCheckOutput(cmd)
+  except common.ExternalError as e:
+    raise ApexSigningError, \
+        'Failed to sign APEX payload {} with {}:\n{}'.format(
+            payload_file, payload_key_path, e), sys.exc_info()[2]
+
+  # Verify the signed payload image with specified public key.
+  logger.info('Verifying %s', payload_file)
+  VerifyApexPayload(payload_file, payload_key_path)
+
+
+def VerifyApexPayload(payload_file, payload_key):
+  """Verifies the APEX payload signature with the given key."""
+  cmd = ['avbtool', 'verify_image', '--image', payload_file,
+         '--key', payload_key]
+  try:
+    common.RunAndCheckOutput(cmd)
+  except common.ExternalError as e:
+    raise ApexSigningError, \
+        'Failed to validate payload signing for {} with {}:\n{}'.format(
+            payload_file, payload_key, e), sys.exc_info()[2]
+
+
+def ParseApexPayloadInfo(payload_path):
+  """Parses the APEX payload info.
+
+  Args:
+    payload_path: The path to the payload image.
+
+  Raises:
+    ApexInfoError on parsing errors.
+
+  Returns:
+    A dict that contains payload property-value pairs. The dict should at least
+    contain Algorithm, Salt and apex.key.
+  """
+  if not os.path.exists(payload_path):
+    raise ApexInfoError('Failed to find image: {}'.format(payload_path))
+
+  cmd = ['avbtool', 'info_image', '--image', payload_path]
+  try:
+    output = common.RunAndCheckOutput(cmd)
+  except common.ExternalError as e:
+    raise ApexInfoError, \
+        'Failed to get APEX payload info for {}:\n{}'.format(
+            payload_path, e), sys.exc_info()[2]
+
+  # Extract the Algorithm / Salt / Prop info from payload (i.e. an image signed
+  # with avbtool). For example,
+  # Algorithm:                SHA256_RSA4096
+  PAYLOAD_INFO_PATTERN = (
+      r'^\s*(?P<key>Algorithm|Salt|Prop)\:\s*(?P<value>.*?)$')
+  payload_info_matcher = re.compile(PAYLOAD_INFO_PATTERN)
+
+  payload_info = {}
+  for line in output.split('\n'):
+    line_info = payload_info_matcher.match(line)
+    if not line_info:
+      continue
+
+    key, value = line_info.group('key'), line_info.group('value')
+
+    if key == 'Prop':
+      # Further extract the property key-value pair, from a 'Prop:' line. For
+      # example,
+      #   Prop: apex.key -> 'com.android.runtime'
+      # Note that avbtool writes single or double quotes around values.
+      PROPERTY_DESCRIPTOR_PATTERN = r'^\s*(?P<key>.*?)\s->\s*(?P<value>.*?)$'
+
+      prop_matcher = re.compile(PROPERTY_DESCRIPTOR_PATTERN)
+      prop = prop_matcher.match(value)
+      if not prop:
+        raise ApexInfoError(
+            'Failed to parse prop string {}'.format(value))
+
+      prop_key, prop_value = prop.group('key'), prop.group('value')
+      if prop_key == 'apex.key':
+        # avbtool dumps the prop value with repr(), which contains single /
+        # double quotes that we don't want.
+        payload_info[prop_key] = prop_value.strip('\"\'')
+
+    else:
+      payload_info[key] = value
+
+  # Sanity check.
+  for key in ('Algorithm', 'Salt', 'apex.key'):
+    if key not in payload_info:
+      raise ApexInfoError(
+          'Failed to find {} prop in {}'.format(key, payload_path))
+
+  return payload_info
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'))
diff --git a/tools/releasetools/testdata/signing_helper.sh b/tools/releasetools/testdata/signing_helper.sh
new file mode 100755
index 0000000..364e023
--- /dev/null
+++ b/tools/releasetools/testdata/signing_helper.sh
@@ -0,0 +1,21 @@
+#!/bin/sh
+#
+# 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.
+#
+
+tmpfile=$(mktemp)
+cat $3 | openssl rsautl -sign -inkey $2 -raw > $tmpfile
+cat $tmpfile > $3
+rm $tmpfile
diff --git a/tools/releasetools/testdata/testkey_with_passwd.key b/tools/releasetools/testdata/testkey_with_passwd.key
new file mode 100644
index 0000000..2f0a199
--- /dev/null
+++ b/tools/releasetools/testdata/testkey_with_passwd.key
@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----