diff --git a/pvmfw/avb/src/descriptor.rs b/pvmfw/avb/src/descriptor.rs
deleted file mode 100644
index cd623ac..0000000
--- a/pvmfw/avb/src/descriptor.rs
+++ /dev/null
@@ -1,201 +0,0 @@
-// Copyright 2023, 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.
-
-//! Structs and functions relating to the descriptors.
-
-use crate::error::{AvbIOError, AvbSlotVerifyError};
-use crate::partition::PartitionName;
-use crate::utils::{self, is_not_null, to_nonnull, to_usize, usize_checked_add};
-use avb_bindgen::{
-    avb_descriptor_foreach, avb_hash_descriptor_validate_and_byteswap, AvbDescriptor,
-    AvbHashDescriptor, AvbVBMetaData, AVB_SHA256_DIGEST_SIZE,
-};
-use core::{
-    ffi::c_void,
-    mem::{size_of, MaybeUninit},
-    ops::Range,
-    slice,
-};
-use tinyvec::ArrayVec;
-
-/// Digest type for kernel and initrd.
-pub type Digest = [u8; AVB_SHA256_DIGEST_SIZE as usize];
-
-/// `HashDescriptors` can have maximum one `HashDescriptor` per known partition.
-#[derive(Default)]
-pub(crate) struct HashDescriptors(
-    ArrayVec<[HashDescriptor; PartitionName::NUM_OF_KNOWN_PARTITIONS]>,
-);
-
-impl HashDescriptors {
-    /// Builds `HashDescriptors` from `AvbVBMetaData`.
-    /// Returns an error if the given `AvbVBMetaData` contains non-hash descriptor, hash
-    /// descriptor of unknown `PartitionName` or duplicated hash descriptors.
-    ///
-    /// # Safety
-    ///
-    /// Behavior is undefined if any of the following conditions are violated:
-    /// * `vbmeta.vbmeta_data` must be non-null and points to a valid VBMeta.
-    /// * `vbmeta.vbmeta_data` must be valid for reading `vbmeta.vbmeta_size` bytes.
-    pub(crate) unsafe fn from_vbmeta(vbmeta: AvbVBMetaData) -> Result<Self, AvbSlotVerifyError> {
-        is_not_null(vbmeta.vbmeta_data).map_err(|_| AvbSlotVerifyError::Io)?;
-        let mut descriptors = Self::default();
-        // SAFETY: It is safe as the raw pointer `vbmeta.vbmeta_data` is a non-null pointer and
-        // points to a valid VBMeta structure.
-        if !unsafe {
-            avb_descriptor_foreach(
-                vbmeta.vbmeta_data,
-                vbmeta.vbmeta_size,
-                Some(check_and_save_descriptor),
-                &mut descriptors as *mut _ as *mut c_void,
-            )
-        } {
-            return Err(AvbSlotVerifyError::InvalidMetadata);
-        }
-        Ok(descriptors)
-    }
-
-    fn push(&mut self, descriptor: HashDescriptor) -> utils::Result<()> {
-        if self.0.iter().any(|d| d.partition_name_eq(&descriptor)) {
-            return Err(AvbIOError::Io);
-        }
-        self.0.push(descriptor);
-        Ok(())
-    }
-
-    pub(crate) fn len(&self) -> usize {
-        self.0.len()
-    }
-
-    /// Finds the `HashDescriptor` for the given `PartitionName`.
-    /// Throws an error if no corresponding descriptor found.
-    pub(crate) fn find(
-        &self,
-        partition_name: PartitionName,
-    ) -> Result<&HashDescriptor, AvbSlotVerifyError> {
-        self.0
-            .iter()
-            .find(|d| d.partition_name == partition_name)
-            .ok_or(AvbSlotVerifyError::InvalidMetadata)
-    }
-}
-
-/// # Safety
-///
-/// Behavior is undefined if any of the following conditions are violated:
-/// * The `descriptor` pointer must be non-null and points to a valid `AvbDescriptor` struct.
-/// * The `user_data` pointer must be non-null and points to a valid `HashDescriptors` struct.
-unsafe extern "C" fn check_and_save_descriptor(
-    descriptor: *const AvbDescriptor,
-    user_data: *mut c_void,
-) -> bool {
-    // SAFETY: It is safe because the caller must ensure that the `descriptor` pointer and
-    // the `user_data` are non-null and valid.
-    unsafe { try_check_and_save_descriptor(descriptor, user_data).is_ok() }
-}
-
-/// # Safety
-///
-/// Behavior is undefined if any of the following conditions are violated:
-/// * The `descriptor` pointer must be non-null and points to a valid `AvbDescriptor` struct.
-/// * The `user_data` pointer must be non-null and points to a valid `HashDescriptors` struct.
-unsafe fn try_check_and_save_descriptor(
-    descriptor: *const AvbDescriptor,
-    user_data: *mut c_void,
-) -> utils::Result<()> {
-    is_not_null(descriptor)?;
-    // SAFETY: It is safe because the caller ensures that `descriptor` is a non-null pointer
-    // pointing to a valid struct.
-    let desc = unsafe { AvbHashDescriptorWrap::from_descriptor_ptr(descriptor)? };
-    // SAFETY: It is safe because the caller ensures that `descriptor` is a non-null pointer
-    // pointing to a valid struct.
-    let data = unsafe { slice::from_raw_parts(descriptor as *const u8, desc.len()?) };
-    let mut descriptors = to_nonnull(user_data as *mut HashDescriptors)?;
-    // SAFETY: It is safe because the caller ensures that `user_data` is a non-null pointer
-    // pointing to a valid struct.
-    let descriptors = unsafe { descriptors.as_mut() };
-    descriptors.push(HashDescriptor::new(&desc, data)?)
-}
-
-#[derive(Default)]
-pub(crate) struct HashDescriptor {
-    partition_name: PartitionName,
-    pub(crate) digest: Digest,
-}
-
-impl HashDescriptor {
-    fn new(desc: &AvbHashDescriptorWrap, data: &[u8]) -> utils::Result<Self> {
-        let partition_name = data
-            .get(desc.partition_name_range()?)
-            .ok_or(AvbIOError::RangeOutsidePartition)?
-            .try_into()?;
-        let partition_digest =
-            data.get(desc.digest_range()?).ok_or(AvbIOError::RangeOutsidePartition)?;
-        let mut digest = [0u8; size_of::<Digest>()];
-        digest.copy_from_slice(partition_digest);
-        Ok(Self { partition_name, digest })
-    }
-
-    fn partition_name_eq(&self, other: &HashDescriptor) -> bool {
-        self.partition_name == other.partition_name
-    }
-}
-
-/// `AvbHashDescriptor` contains the metadata for the given descriptor.
-struct AvbHashDescriptorWrap(AvbHashDescriptor);
-
-impl AvbHashDescriptorWrap {
-    /// # Safety
-    ///
-    /// Behavior is undefined if any of the following conditions are violated:
-    /// * The `descriptor` pointer must be non-null and point to a valid `AvbDescriptor`.
-    unsafe fn from_descriptor_ptr(descriptor: *const AvbDescriptor) -> utils::Result<Self> {
-        is_not_null(descriptor)?;
-        // SAFETY: It is safe as the raw pointer `descriptor` is non-null and points to
-        // a valid `AvbDescriptor`.
-        let desc = unsafe {
-            let mut desc = MaybeUninit::uninit();
-            if !avb_hash_descriptor_validate_and_byteswap(
-                descriptor as *const AvbHashDescriptor,
-                desc.as_mut_ptr(),
-            ) {
-                return Err(AvbIOError::Io);
-            }
-            desc.assume_init()
-        };
-        Ok(Self(desc))
-    }
-
-    fn len(&self) -> utils::Result<usize> {
-        usize_checked_add(
-            size_of::<AvbDescriptor>(),
-            to_usize(self.0.parent_descriptor.num_bytes_following)?,
-        )
-    }
-
-    fn partition_name_end(&self) -> utils::Result<usize> {
-        usize_checked_add(size_of::<AvbHashDescriptor>(), to_usize(self.0.partition_name_len)?)
-    }
-
-    fn partition_name_range(&self) -> utils::Result<Range<usize>> {
-        let start = size_of::<AvbHashDescriptor>();
-        Ok(start..(self.partition_name_end()?))
-    }
-
-    fn digest_range(&self) -> utils::Result<Range<usize>> {
-        let start = usize_checked_add(self.partition_name_end()?, to_usize(self.0.salt_len)?)?;
-        let end = usize_checked_add(start, to_usize(self.0.digest_len)?)?;
-        Ok(start..end)
-    }
-}
diff --git a/pvmfw/avb/src/descriptor/descriptors.rs b/pvmfw/avb/src/descriptor/descriptors.rs
new file mode 100644
index 0000000..b577adf
--- /dev/null
+++ b/pvmfw/avb/src/descriptor/descriptors.rs
@@ -0,0 +1,140 @@
+// Copyright 2023, 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.
+
+//! Structs and functions relating to the descriptor data.
+
+use crate::error::AvbIOError;
+use crate::partition::PartitionName;
+use crate::utils::{self, is_not_null, to_usize, usize_checked_add};
+use crate::Digest;
+use avb_bindgen::{
+    avb_descriptor_validate_and_byteswap, avb_hash_descriptor_validate_and_byteswap, AvbDescriptor,
+    AvbDescriptorTag, AvbHashDescriptor,
+};
+use core::{
+    mem::{size_of, MaybeUninit},
+    ops::Range,
+    slice,
+};
+
+pub(super) enum Descriptor {
+    Hash(HashDescriptor),
+}
+
+impl Descriptor {
+    /// # Safety
+    ///
+    /// Behavior is undefined if any of the following conditions are violated:
+    /// * The `descriptor` pointer must be non-null and point to a valid `AvbDescriptor`.
+    pub(super) unsafe fn from_descriptor_ptr(
+        descriptor: *const AvbDescriptor,
+    ) -> utils::Result<Self> {
+        // SAFETY: It is safe as the raw pointer `descriptor` is non-null and points to
+        // a valid `AvbDescriptor`.
+        let avb_descriptor =
+            unsafe { get_valid_descriptor(descriptor, avb_descriptor_validate_and_byteswap)? };
+        let len = usize_checked_add(
+            size_of::<AvbDescriptor>(),
+            to_usize(avb_descriptor.num_bytes_following)?,
+        )?;
+        // SAFETY: It is safe because the caller ensures that `descriptor` is a non-null pointer
+        // pointing to a valid struct.
+        let data = unsafe { slice::from_raw_parts(descriptor as *const u8, len) };
+        match avb_descriptor.tag.try_into() {
+            Ok(AvbDescriptorTag::AVB_DESCRIPTOR_TAG_HASH) => {
+                // SAFETY: It is safe because the caller ensures that `descriptor` is a non-null
+                // pointer pointing to a valid struct.
+                let h = unsafe { HashDescriptorHeader::from_descriptor_ptr(descriptor)? };
+                Ok(Self::Hash(HashDescriptor::new(&h, data)?))
+            }
+            _ => Err(AvbIOError::NoSuchValue),
+        }
+    }
+}
+
+struct HashDescriptorHeader(AvbHashDescriptor);
+
+impl HashDescriptorHeader {
+    /// # Safety
+    ///
+    /// Behavior is undefined if any of the following conditions are violated:
+    /// * The `descriptor` pointer must be non-null and point to a valid `AvbDescriptor`.
+    unsafe fn from_descriptor_ptr(descriptor: *const AvbDescriptor) -> utils::Result<Self> {
+        // SAFETY: It is safe as the raw pointer `descriptor` is non-null and points to
+        // a valid `AvbDescriptor`.
+        unsafe {
+            get_valid_descriptor(
+                descriptor as *const AvbHashDescriptor,
+                avb_hash_descriptor_validate_and_byteswap,
+            )
+            .map(Self)
+        }
+    }
+
+    fn partition_name_end(&self) -> utils::Result<usize> {
+        usize_checked_add(size_of::<AvbHashDescriptor>(), to_usize(self.0.partition_name_len)?)
+    }
+
+    fn partition_name_range(&self) -> utils::Result<Range<usize>> {
+        let start = size_of::<AvbHashDescriptor>();
+        Ok(start..(self.partition_name_end()?))
+    }
+
+    fn digest_range(&self) -> utils::Result<Range<usize>> {
+        let start = usize_checked_add(self.partition_name_end()?, to_usize(self.0.salt_len)?)?;
+        let end = usize_checked_add(start, to_usize(self.0.digest_len)?)?;
+        Ok(start..end)
+    }
+}
+
+/// # Safety
+///
+/// Behavior is undefined if any of the following conditions are violated:
+/// * The `descriptor_ptr` pointer must be non-null and point to a valid `AvbDescriptor`.
+unsafe fn get_valid_descriptor<T>(
+    descriptor_ptr: *const T,
+    descriptor_validate_and_byteswap: unsafe extern "C" fn(src: *const T, dest: *mut T) -> bool,
+) -> utils::Result<T> {
+    is_not_null(descriptor_ptr)?;
+    // SAFETY: It is safe because the caller ensures that `descriptor_ptr` is a non-null pointer
+    // pointing to a valid struct.
+    let descriptor = unsafe {
+        let mut desc = MaybeUninit::uninit();
+        if !descriptor_validate_and_byteswap(descriptor_ptr, desc.as_mut_ptr()) {
+            return Err(AvbIOError::Io);
+        }
+        desc.assume_init()
+    };
+    Ok(descriptor)
+}
+
+#[derive(Default)]
+pub(crate) struct HashDescriptor {
+    pub(crate) partition_name: PartitionName,
+    pub(crate) digest: Digest,
+}
+
+impl HashDescriptor {
+    fn new(desc: &HashDescriptorHeader, data: &[u8]) -> utils::Result<Self> {
+        let partition_name = data
+            .get(desc.partition_name_range()?)
+            .ok_or(AvbIOError::RangeOutsidePartition)?
+            .try_into()?;
+        let partition_digest =
+            data.get(desc.digest_range()?).ok_or(AvbIOError::RangeOutsidePartition)?;
+        let mut digest = [0u8; size_of::<Digest>()];
+        digest.copy_from_slice(partition_digest);
+        Ok(Self { partition_name, digest })
+    }
+}
diff --git a/pvmfw/avb/src/descriptor/mod.rs b/pvmfw/avb/src/descriptor/mod.rs
new file mode 100644
index 0000000..67f85d9
--- /dev/null
+++ b/pvmfw/avb/src/descriptor/mod.rs
@@ -0,0 +1,129 @@
+// Copyright 2023, 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.
+
+//! Structs and functions relating to the descriptors.
+
+mod descriptors;
+
+pub(crate) use self::descriptors::HashDescriptor;
+
+use self::descriptors::Descriptor;
+use crate::error::{AvbIOError, AvbSlotVerifyError};
+use crate::partition::PartitionName;
+use crate::utils::{self, is_not_null, to_nonnull};
+use avb_bindgen::{avb_descriptor_foreach, AvbDescriptor, AvbVBMetaData, AVB_SHA256_DIGEST_SIZE};
+use core::ffi::c_void;
+use tinyvec::ArrayVec;
+
+/// Digest type for kernel and initrd.
+pub type Digest = [u8; AVB_SHA256_DIGEST_SIZE as usize];
+
+/// `Descriptors` can have at most one `HashDescriptor` per known partition and at most one
+/// `PropertyDescriptor`.
+#[derive(Default)]
+pub(crate) struct Descriptors {
+    hash_descriptors: ArrayVec<[HashDescriptor; PartitionName::NUM_OF_KNOWN_PARTITIONS]>,
+}
+
+impl Descriptors {
+    /// Builds `Descriptors` from `AvbVBMetaData`.
+    /// Returns an error if the given `AvbVBMetaData` contains non-hash descriptor, hash
+    /// descriptor of unknown `PartitionName` or duplicated hash descriptors.
+    ///
+    /// # Safety
+    ///
+    /// Behavior is undefined if any of the following conditions are violated:
+    /// * `vbmeta.vbmeta_data` must be non-null and points to a valid VBMeta.
+    /// * `vbmeta.vbmeta_data` must be valid for reading `vbmeta.vbmeta_size` bytes.
+    pub(crate) unsafe fn from_vbmeta(vbmeta: AvbVBMetaData) -> Result<Self, AvbSlotVerifyError> {
+        is_not_null(vbmeta.vbmeta_data).map_err(|_| AvbSlotVerifyError::Io)?;
+        let mut descriptors = Self::default();
+        // SAFETY: It is safe as the raw pointer `vbmeta.vbmeta_data` is a non-null pointer and
+        // points to a valid VBMeta structure.
+        if !unsafe {
+            avb_descriptor_foreach(
+                vbmeta.vbmeta_data,
+                vbmeta.vbmeta_size,
+                Some(check_and_save_descriptor),
+                &mut descriptors as *mut _ as *mut c_void,
+            )
+        } {
+            return Err(AvbSlotVerifyError::InvalidMetadata);
+        }
+        Ok(descriptors)
+    }
+
+    pub(crate) fn num_hash_descriptor(&self) -> usize {
+        self.hash_descriptors.len()
+    }
+
+    /// Finds the `HashDescriptor` for the given `PartitionName`.
+    /// Throws an error if no corresponding descriptor found.
+    pub(crate) fn find_hash_descriptor(
+        &self,
+        partition_name: PartitionName,
+    ) -> Result<&HashDescriptor, AvbSlotVerifyError> {
+        self.hash_descriptors
+            .iter()
+            .find(|d| d.partition_name == partition_name)
+            .ok_or(AvbSlotVerifyError::InvalidMetadata)
+    }
+
+    fn push(&mut self, descriptor: Descriptor) -> utils::Result<()> {
+        match descriptor {
+            Descriptor::Hash(d) => self.push_hash_descriptor(d),
+        }
+    }
+
+    fn push_hash_descriptor(&mut self, descriptor: HashDescriptor) -> utils::Result<()> {
+        if self.hash_descriptors.iter().any(|d| d.partition_name == descriptor.partition_name) {
+            return Err(AvbIOError::Io);
+        }
+        self.hash_descriptors.push(descriptor);
+        Ok(())
+    }
+}
+
+/// # Safety
+///
+/// Behavior is undefined if any of the following conditions are violated:
+/// * The `descriptor` pointer must be non-null and points to a valid `AvbDescriptor` struct.
+/// * The `user_data` pointer must be non-null and points to a valid `Descriptors` struct.
+unsafe extern "C" fn check_and_save_descriptor(
+    descriptor: *const AvbDescriptor,
+    user_data: *mut c_void,
+) -> bool {
+    // SAFETY: It is safe because the caller must ensure that the `descriptor` pointer and
+    // the `user_data` are non-null and valid.
+    unsafe { try_check_and_save_descriptor(descriptor, user_data).is_ok() }
+}
+
+/// # Safety
+///
+/// Behavior is undefined if any of the following conditions are violated:
+/// * The `descriptor` pointer must be non-null and points to a valid `AvbDescriptor` struct.
+/// * The `user_data` pointer must be non-null and points to a valid `Descriptors` struct.
+unsafe fn try_check_and_save_descriptor(
+    descriptor: *const AvbDescriptor,
+    user_data: *mut c_void,
+) -> utils::Result<()> {
+    let mut descriptors = to_nonnull(user_data as *mut Descriptors)?;
+    // SAFETY: It is safe because the caller ensures that `user_data` is a non-null pointer
+    // pointing to a valid struct.
+    let descriptors = unsafe { descriptors.as_mut() };
+    // SAFETY: It is safe because the caller ensures that `descriptor` is a non-null pointer
+    // pointing to a valid struct.
+    let descriptor = unsafe { Descriptor::from_descriptor_ptr(descriptor)? };
+    descriptors.push(descriptor)
+}
diff --git a/pvmfw/avb/src/error.rs b/pvmfw/avb/src/error.rs
index 674e5a7..c2b7428 100644
--- a/pvmfw/avb/src/error.rs
+++ b/pvmfw/avb/src/error.rs
@@ -93,7 +93,6 @@
     #[allow(dead_code)]
     Oom,
     /// AVB_IO_RESULT_ERROR_IO,
-    #[allow(dead_code)]
     Io,
     /// AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION,
     NoSuchPartition,
diff --git a/pvmfw/avb/src/verify.rs b/pvmfw/avb/src/verify.rs
index b03506c..05a6492 100644
--- a/pvmfw/avb/src/verify.rs
+++ b/pvmfw/avb/src/verify.rs
@@ -14,7 +14,7 @@
 
 //! This module handles the pvmfw payload verification.
 
-use crate::descriptor::{Digest, HashDescriptors};
+use crate::descriptor::{Descriptors, Digest};
 use crate::error::AvbSlotVerifyError;
 use crate::ops::{Ops, Payload};
 use crate::partition::PartitionName;
@@ -63,9 +63,9 @@
 }
 
 fn verify_vbmeta_has_only_one_hash_descriptor(
-    hash_descriptors: &HashDescriptors,
+    descriptors: &Descriptors,
 ) -> Result<(), AvbSlotVerifyError> {
-    if hash_descriptors.len() == 1 {
+    if descriptors.num_hash_descriptor() == 1 {
         Ok(())
     } else {
         Err(AvbSlotVerifyError::InvalidMetadata)
@@ -112,11 +112,11 @@
     // SAFETY: It is safe because the `vbmeta_image` is collected from `AvbSlotVerifyData`,
     // which is returned by `avb_slot_verify()` when the verification succeeds. It is
     // guaranteed by libavb to be non-null and to point to a valid VBMeta structure.
-    let hash_descriptors = unsafe { HashDescriptors::from_vbmeta(vbmeta_image)? };
-    let kernel_descriptor = hash_descriptors.find(PartitionName::Kernel)?;
+    let descriptors = unsafe { Descriptors::from_vbmeta(vbmeta_image)? };
+    let kernel_descriptor = descriptors.find_hash_descriptor(PartitionName::Kernel)?;
 
     if initrd.is_none() {
-        verify_vbmeta_has_only_one_hash_descriptor(&hash_descriptors)?;
+        verify_vbmeta_has_only_one_hash_descriptor(&descriptors)?;
         return Ok(VerifiedBootData {
             debug_level: DebugLevel::None,
             kernel_digest: kernel_descriptor.digest,
@@ -140,7 +140,7 @@
         initrd_partition_name,
         initrd.len(),
     )?;
-    let initrd_descriptor = hash_descriptors.find(initrd_partition_name)?;
+    let initrd_descriptor = descriptors.find_hash_descriptor(initrd_partition_name)?;
     Ok(VerifiedBootData {
         debug_level,
         kernel_digest: kernel_descriptor.digest,