diff --git a/microdroid_manager/src/payload.rs b/microdroid_manager/src/payload.rs
index 48535f3..a553ce4 100644
--- a/microdroid_manager/src/payload.rs
+++ b/microdroid_manager/src/payload.rs
@@ -14,12 +14,10 @@
 
 //! Routines for handling payload
 
-mod apex;
-
 use crate::instance::ApexData;
 use crate::ioutil::wait_for_file;
 use anyhow::Result;
-use apex::verify;
+use apexutil::verify;
 use log::info;
 use microdroid_metadata::{read_metadata, ApexPayload, Metadata};
 use std::time::Duration;
diff --git a/microdroid_manager/src/payload/apex.rs b/microdroid_manager/src/payload/apex.rs
deleted file mode 100644
index d53e907..0000000
--- a/microdroid_manager/src/payload/apex.rs
+++ /dev/null
@@ -1,312 +0,0 @@
-// Copyright 2021, 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.
-
-//! Routines for handling APEX payload
-
-use avb_bindgen::*;
-use std::ffi::{c_void, CStr};
-use std::fs::File;
-use std::io::{self, Read, Seek, SeekFrom};
-use std::mem::{size_of, zeroed};
-use std::ops::Deref;
-use std::ptr::null_mut;
-use std::slice::{from_raw_parts, from_raw_parts_mut};
-use thiserror::Error;
-use zip::result::ZipError;
-use zip::ZipArchive;
-
-const APEX_PUBKEY_ENTRY: &str = "apex_pubkey";
-const APEX_PAYLOAD_ENTRY: &str = "apex_payload.img";
-
-/// Errors from parsing an APEX.
-#[derive(Debug, Error)]
-pub enum ApexParseError {
-    /// There was an IO error.
-    #[error("IO error")]
-    Io(#[from] io::Error),
-    /// The Zip archive was invalid.
-    #[error("Cannot read zip archive")]
-    InvalidZip(&'static str),
-    /// The apex_pubkey file was missing from the APEX.
-    #[error("APEX doesn't contain apex_pubkey")]
-    PubkeyMissing,
-    /// The apex_payload.img file was missing from the APEX.
-    #[error("APEX doesn't contain apex_payload.img")]
-    PayloadMissing,
-    /// The AVB footer in the APEX payload was invalid.
-    #[error("Cannot validate APEX payload AVB footer")]
-    InvalidPayloadAvbFooter,
-    /// There were no descriptors in the APEX payload's AVB footer.
-    #[error("No descriptors found in payload AVB footer")]
-    NoDescriptors,
-    /// There was an invalid descriptor in the APEX payload's AVB footer.
-    #[error("Invalid descriptor found in payload AVB footer")]
-    InvalidDescriptor,
-    /// There was no hashtree descriptor in the APEX payload's AVB footer.
-    #[error("Non-hashtree descriptor found in payload AVB footer")]
-    DescriptorNotHashtree,
-    /// There was an invalid hashtree descriptor in the APEX payload's AVB footer.
-    #[error("Invalid hashtree descriptor found in payload AVB footer")]
-    InvalidHashtreeDescriptor,
-}
-
-/// Errors from verifying an APEX.
-#[derive(Debug, Error)]
-pub enum ApexVerificationError {
-    /// There was an error parsing the APEX.
-    #[error("Cannot parse APEX file")]
-    ParseError(#[from] ApexParseError),
-    /// The APEX payload signature did not validate.
-    #[error("Cannot verify payload signature")]
-    BadPayloadSignature(String),
-    /// The APEX payload was signed with a different key.
-    #[error("Payload is signed with the wrong key")]
-    BadPayloadKey,
-}
-
-/// Verification result holds public key and root digest of apex_payload.img
-pub struct ApexVerificationResult {
-    /// The public key that verifies the payload signature.
-    pub public_key: Vec<u8>,
-    /// The root digest of the payload hashtree.
-    pub root_digest: Vec<u8>,
-}
-
-/// Verify APEX payload by AVB verification and return public key and root digest
-pub fn verify(path: &str) -> Result<ApexVerificationResult, ApexVerificationError> {
-    let apex_file = File::open(path).map_err(ApexParseError::Io)?;
-    let (public_key, image_offset, image_size) = get_public_key_and_image_info(&apex_file)?;
-    let root_digest = verify_vbmeta(apex_file, image_offset, image_size, &public_key)?;
-    Ok(ApexVerificationResult { public_key, root_digest })
-}
-
-fn get_public_key_and_image_info(apex_file: &File) -> Result<(Vec<u8>, u64, u64), ApexParseError> {
-    let mut z = ZipArchive::new(apex_file).map_err(|err| match err {
-        ZipError::Io(err) => ApexParseError::Io(err),
-        ZipError::InvalidArchive(s) | ZipError::UnsupportedArchive(s) => {
-            ApexParseError::InvalidZip(s)
-        }
-        ZipError::FileNotFound => unreachable!(),
-    })?;
-
-    let mut public_key = Vec::new();
-    z.by_name(APEX_PUBKEY_ENTRY)
-        .map_err(|err| match err {
-            ZipError::Io(err) => ApexParseError::Io(err),
-            ZipError::FileNotFound => ApexParseError::PubkeyMissing,
-            ZipError::InvalidArchive(s) | ZipError::UnsupportedArchive(s) => {
-                ApexParseError::InvalidZip(s)
-            }
-        })?
-        .read_to_end(&mut public_key)?;
-
-    let (image_offset, image_size) = z
-        .by_name(APEX_PAYLOAD_ENTRY)
-        .map(|f| (f.data_start(), f.size()))
-        .map_err(|err| match err {
-            ZipError::Io(err) => ApexParseError::Io(err),
-            ZipError::FileNotFound => ApexParseError::PayloadMissing,
-            ZipError::InvalidArchive(s) | ZipError::UnsupportedArchive(s) => {
-                ApexParseError::InvalidZip(s)
-            }
-        })?;
-
-    Ok((public_key, image_offset, image_size))
-}
-
-// Manual addition of a missing enum
-#[allow(non_camel_case_types, dead_code)]
-#[repr(u8)]
-enum AvbDescriptorTag {
-    AVB_DESCRIPTOR_TAG_PROPERTY = 0,
-    AVB_DESCRIPTOR_TAG_HASHTREE,
-    AVB_DESCRIPTOR_TAG_HASH,
-    AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE,
-    AVB_DESCRIPTOR_TAG_CHAIN_PARTITION,
-}
-
-const FOOTER_SIZE: usize = size_of::<AvbFooter>();
-const HASHTREE_DESCRIPTOR_SIZE: usize = size_of::<AvbHashtreeDescriptor>();
-
-/// Verify VBmeta image and return root digest
-fn verify_vbmeta<R: Read + Seek>(
-    image: R,
-    offset: u64,
-    size: u64,
-    public_key: &[u8],
-) -> Result<Vec<u8>, ApexVerificationError> {
-    let vbmeta = VbMeta::from(image, offset, size)?;
-    vbmeta.verify(public_key)?;
-    for &descriptor in vbmeta.descriptors()?.iter() {
-        if let Ok(hashtree_descriptor) = HashtreeDescriptor::from(descriptor) {
-            return Ok(hashtree_descriptor.root_digest());
-        }
-    }
-    Err(ApexParseError::DescriptorNotHashtree.into())
-}
-
-struct VbMeta {
-    data: Vec<u8>,
-}
-
-impl VbMeta {
-    // Read a VbMeta data from a given image
-    fn from<R: Read + Seek>(
-        mut image: R,
-        offset: u64,
-        size: u64,
-    ) -> Result<VbMeta, ApexParseError> {
-        // Get AvbFooter first
-        image.seek(SeekFrom::Start(offset + size - FOOTER_SIZE as u64))?;
-        // SAFETY: AvbDescriptor is a "repr(C,packed)" struct from bindgen
-        let mut footer: AvbFooter = unsafe { zeroed() };
-        // SAFETY: safe to read because of seek(-FOOTER_SIZE) above
-        let avb_footer_valid = unsafe {
-            let footer_slice = from_raw_parts_mut(&mut footer as *mut _ as *mut u8, FOOTER_SIZE);
-            image.read_exact(footer_slice)?;
-            avb_footer_validate_and_byteswap(&footer, &mut footer)
-        };
-        if !avb_footer_valid {
-            return Err(ApexParseError::InvalidPayloadAvbFooter);
-        }
-        // Get VbMeta block
-        image.seek(SeekFrom::Start(offset + footer.vbmeta_offset))?;
-        let vbmeta_size = footer.vbmeta_size as usize;
-        let mut data = vec![0u8; vbmeta_size];
-        image.read_exact(&mut data)?;
-        Ok(VbMeta { data })
-    }
-    // Verify VbMeta image. Its enclosed public key should match with a given public key.
-    fn verify(&self, outer_public_key: &[u8]) -> Result<(), ApexVerificationError> {
-        // SAFETY: self.data points to a valid VBMeta data and avb_vbmeta_image_verify should work fine
-        // with it
-        let public_key = unsafe {
-            let mut pk_ptr: *const u8 = null_mut();
-            let mut pk_len: usize = 0;
-            let res = avb_vbmeta_image_verify(
-                self.data.as_ptr(),
-                self.data.len(),
-                &mut pk_ptr,
-                &mut pk_len,
-            );
-            if res != AvbVBMetaVerifyResult_AVB_VBMETA_VERIFY_RESULT_OK {
-                return Err(ApexVerificationError::BadPayloadSignature(
-                    CStr::from_ptr(avb_vbmeta_verify_result_to_string(res))
-                        .to_string_lossy()
-                        .into_owned(),
-                ));
-            }
-            from_raw_parts(pk_ptr, pk_len)
-        };
-
-        if public_key != outer_public_key {
-            return Err(ApexVerificationError::BadPayloadKey);
-        }
-        Ok(())
-    }
-    // Return a slice of AvbDescriptor pointers
-    fn descriptors(&self) -> Result<Descriptors, ApexParseError> {
-        let mut num: usize = 0;
-        // SAFETY: ptr will be freed by Descriptor.
-        Ok(unsafe {
-            let ptr = avb_descriptor_get_all(self.data.as_ptr(), self.data.len(), &mut num);
-            if ptr.is_null() {
-                return Err(ApexParseError::NoDescriptors);
-            }
-            let all = from_raw_parts(ptr, num);
-            Descriptors { ptr, all }
-        })
-    }
-}
-
-struct HashtreeDescriptor {
-    ptr: *const u8,
-    inner: AvbHashtreeDescriptor,
-}
-
-impl HashtreeDescriptor {
-    fn from(descriptor: *const AvbDescriptor) -> Result<HashtreeDescriptor, ApexParseError> {
-        // SAFETY: AvbDescriptor is a "repr(C,packed)" struct from bindgen
-        let mut desc: AvbDescriptor = unsafe { zeroed() };
-        // SAFETY: both points to valid AvbDescriptor pointers
-        if !unsafe { avb_descriptor_validate_and_byteswap(descriptor, &mut desc) } {
-            return Err(ApexParseError::InvalidDescriptor);
-        }
-        if desc.tag != AvbDescriptorTag::AVB_DESCRIPTOR_TAG_HASHTREE as u64 {
-            return Err(ApexParseError::DescriptorNotHashtree);
-        }
-        // SAFETY: AvbHashtreeDescriptor is a "repr(C, packed)" struct from bindgen
-        let mut hashtree_descriptor: AvbHashtreeDescriptor = unsafe { zeroed() };
-        // SAFETY: With tag == AVB_DESCRIPTOR_TAG_HASHTREE, descriptor should point to
-        // a AvbHashtreeDescriptor.
-        if !unsafe {
-            avb_hashtree_descriptor_validate_and_byteswap(
-                descriptor as *const AvbHashtreeDescriptor,
-                &mut hashtree_descriptor,
-            )
-        } {
-            return Err(ApexParseError::InvalidHashtreeDescriptor);
-        }
-        Ok(Self { ptr: descriptor as *const u8, inner: hashtree_descriptor })
-    }
-    fn root_digest(&self) -> Vec<u8> {
-        // SAFETY: digest_ptr should point to a valid buffer of root_digest_len
-        let root_digest = unsafe {
-            let digest_ptr = self.ptr.offset(
-                HASHTREE_DESCRIPTOR_SIZE as isize
-                    + self.inner.partition_name_len as isize
-                    + self.inner.salt_len as isize,
-            );
-            from_raw_parts(digest_ptr, self.inner.root_digest_len as usize)
-        };
-        root_digest.to_owned()
-    }
-}
-
-// Wraps pointer to a heap-allocated array of AvbDescriptor pointers
-struct Descriptors<'a> {
-    ptr: *mut *const AvbDescriptor,
-    all: &'a [*const AvbDescriptor],
-}
-
-// Wrapped pointer should be freed with avb_free.
-impl Drop for Descriptors<'_> {
-    fn drop(&mut self) {
-        // SAFETY: ptr is allocated by avb_descriptor_get_all
-        unsafe { avb_free(self.ptr as *mut c_void) }
-    }
-}
-
-impl<'a> Deref for Descriptors<'a> {
-    type Target = &'a [*const AvbDescriptor];
-    fn deref(&self) -> &Self::Target {
-        &self.all
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    fn to_hex_string(buf: &[u8]) -> String {
-        buf.iter().map(|b| format!("{:02x}", b)).collect()
-    }
-    #[test]
-    fn test_open_apex() {
-        let res = verify("tests/data/test.apex").unwrap();
-        assert_eq!(
-            to_hex_string(&res.root_digest),
-            "fe11ab17da0a3a738b54bdc3a13f6139cbdf91ec32f001f8d4bbbf8938e04e39"
-        );
-    }
-}