diff --git a/libs/apkverify/Android.bp b/libs/apkverify/Android.bp
index 1c18d2d..4c5a622 100644
--- a/libs/apkverify/Android.bp
+++ b/libs/apkverify/Android.bp
@@ -48,10 +48,12 @@
     test_suites: ["general-tests"],
     rustlibs: [
         "libandroid_logger",
+        "libanyhow",
         "libapkverify",
         "libapkzip",
         "libbyteorder",
         "liblog_rust",
+        "libopenssl",
         "libzip",
     ],
     data: ["tests/data/*"],
diff --git a/libs/apkverify/src/lib.rs b/libs/apkverify/src/lib.rs
index 6af8122..1f3c74f 100644
--- a/libs/apkverify/src/lib.rs
+++ b/libs/apkverify/src/lib.rs
@@ -26,5 +26,5 @@
 mod v4;
 
 pub use algorithms::{HashAlgorithm, SignatureAlgorithmID};
-pub use v3::{get_public_key_der, verify};
+pub use v3::{extract_signed_data, verify, SignedData};
 pub use v4::{get_apk_digest, V4Signature};
diff --git a/libs/apkverify/src/v3.rs b/libs/apkverify/src/v3.rs
index 8a8ad73..88644c7 100644
--- a/libs/apkverify/src/v3.rs
+++ b/libs/apkverify/src/v3.rs
@@ -44,13 +44,9 @@
     public_key: PKey<pkey::Public>,
 }
 
-impl Signer {
-    fn sdk_range(&self) -> RangeInclusive<u32> {
-        self.min_sdk..=self.max_sdk
-    }
-}
-
-struct SignedData {
+/// Contains the signed data part of an APK v3 signature.
+#[derive(Debug)]
+pub struct SignedData {
     digests: LengthPrefixed<Vec<LengthPrefixed<Digest>>>,
     certificates: LengthPrefixed<Vec<LengthPrefixed<X509Certificate>>>,
     min_sdk: u32,
@@ -59,20 +55,6 @@
     additional_attributes: LengthPrefixed<Vec<LengthPrefixed<AdditionalAttributes>>>,
 }
 
-impl SignedData {
-    fn sdk_range(&self) -> RangeInclusive<u32> {
-        self.min_sdk..=self.max_sdk
-    }
-
-    fn find_digest_by_algorithm(&self, algorithm_id: SignatureAlgorithmID) -> Result<&Digest> {
-        Ok(self
-            .digests
-            .iter()
-            .find(|&dig| dig.signature_algorithm_id == Some(algorithm_id))
-            .context(format!("Digest not found for algorithm: {:?}", algorithm_id))?)
-    }
-}
-
 #[derive(Debug)]
 pub(crate) struct Signature {
     /// Option is used here to allow us to ignore unsupported algorithm.
@@ -80,6 +62,7 @@
     signature: LengthPrefixed<Bytes>,
 }
 
+#[derive(Debug)]
 struct Digest {
     signature_algorithm_id: Option<SignatureAlgorithmID>,
     digest: LengthPrefixed<Bytes>,
@@ -88,19 +71,19 @@
 type X509Certificate = Bytes;
 type AdditionalAttributes = Bytes;
 
-/// Verifies APK Signature Scheme v3 signatures of the provided APK and returns the public key
-/// associated with the signer in DER format.
-pub fn verify<P: AsRef<Path>>(apk_path: P, current_sdk: u32) -> Result<Box<[u8]>> {
+/// Verifies APK Signature Scheme v3 signatures of the provided APK and returns the SignedData from
+/// the signature.
+pub fn verify<P: AsRef<Path>>(apk_path: P, current_sdk: u32) -> Result<SignedData> {
     let apk = File::open(apk_path.as_ref())?;
     let (signer, mut sections) = extract_signer_and_apk_sections(apk, current_sdk)?;
     signer.verify(&mut sections)
 }
 
-/// Gets the public key (in DER format) that was used to sign the given APK/APEX file
-pub fn get_public_key_der<P: AsRef<Path>>(apk_path: P, current_sdk: u32) -> Result<Box<[u8]>> {
+/// Extracts the SignedData from the signature of the given APK. (The signature is not verified.)
+pub fn extract_signed_data<P: AsRef<Path>>(apk_path: P, current_sdk: u32) -> Result<SignedData> {
     let apk = File::open(apk_path.as_ref())?;
     let (signer, _) = extract_signer_and_apk_sections(apk, current_sdk)?;
-    Ok(signer.public_key.public_key_to_der()?.into_boxed_slice())
+    signer.parse_signed_data()
 }
 
 pub(crate) fn extract_signer_and_apk_sections<R: Read + Seek>(
@@ -123,6 +106,10 @@
 }
 
 impl Signer {
+    fn sdk_range(&self) -> RangeInclusive<u32> {
+        self.min_sdk..=self.max_sdk
+    }
+
     /// Selects the signature that has the strongest supported `SignatureAlgorithmID`.
     /// The strongest signature is used in both v3 verification and v4 apk digest computation.
     pub(crate) fn strongest_signature(&self) -> Result<&Signature> {
@@ -143,27 +130,33 @@
         Ok(digest.digest.as_ref().to_vec().into_boxed_slice())
     }
 
-    /// Verifies the strongest signature from signatures against signed data using public key.
-    /// Returns the verified signed data.
-    fn verify_signature(&self, strongest: &Signature) -> Result<SignedData> {
-        let mut verifier = strongest
+    /// Verifies a signature over the signed data using the public key.
+    fn verify_signature(&self, signature: &Signature) -> Result<()> {
+        let mut verifier = signature
             .signature_algorithm_id
             .context("Unsupported algorithm")?
             .new_verifier(&self.public_key)?;
         verifier.update(&self.signed_data)?;
-        ensure!(verifier.verify(&strongest.signature)?, "Signature is invalid.");
-        // It is now safe to parse signed data.
+        ensure!(verifier.verify(&signature.signature)?, "Signature is invalid.");
+        Ok(())
+    }
+
+    /// Returns the signed data, converted from bytes.
+    fn parse_signed_data(&self) -> Result<SignedData> {
         self.signed_data.slice(..).read()
     }
 
     /// The steps in this method implements APK Signature Scheme v3 verification step 3.
-    fn verify<R: Read + Seek>(&self, sections: &mut ApkSections<R>) -> Result<Box<[u8]>> {
+    fn verify<R: Read + Seek>(&self, sections: &mut ApkSections<R>) -> Result<SignedData> {
         // 1. Choose the strongest supported signature algorithm ID from signatures.
         let strongest = self.strongest_signature()?;
 
         // 2. Verify the corresponding signature from signatures against signed data using public
         // key.
-        let verified_signed_data = self.verify_signature(strongest)?;
+        self.verify_signature(strongest)?;
+
+        // It is now safe to parse signed data.
+        let verified_signed_data = self.parse_signed_data()?;
 
         // 3. Verify the min and max SDK versions in the signed data match those specified for the
         //    signer.
@@ -199,8 +192,7 @@
 
         // 7. Verify that public key of the first certificate of certificates is identical to public
         //    key.
-        let cert = verified_signed_data.certificates.first().context("No certificates listed")?;
-        let cert = X509::from_der(cert.as_ref())?;
+        let cert = X509::from_der(verified_signed_data.first_certificate_der()?)?;
         ensure!(
             cert.public_key()?.public_eq(&self.public_key),
             "Public key mismatch between certificate and signature record"
@@ -209,7 +201,29 @@
         // TODO(b/245914104)
         // 8. If the proof-of-rotation attribute exists for the signer verify that the
         // struct is valid and this signer is the last certificate in the list.
-        Ok(self.public_key.public_key_to_der()?.into_boxed_slice())
+
+        Ok(verified_signed_data)
+    }
+}
+
+impl SignedData {
+    /// Returns the first X.509 certificate in the signed data, encoded in DER form. (All other
+    /// certificates are ignored for v3; this certificate describes the public key that was actually
+    /// used to sign the APK.)
+    pub fn first_certificate_der(&self) -> Result<&[u8]> {
+        Ok(self.certificates.first().context("No certificates listed")?)
+    }
+
+    fn sdk_range(&self) -> RangeInclusive<u32> {
+        self.min_sdk..=self.max_sdk
+    }
+
+    fn find_digest_by_algorithm(&self, algorithm_id: SignatureAlgorithmID) -> Result<&Digest> {
+        Ok(self
+            .digests
+            .iter()
+            .find(|&dig| dig.signature_algorithm_id == Some(algorithm_id))
+            .context(format!("Digest not found for algorithm: {:?}", algorithm_id))?)
     }
 }
 
diff --git a/libs/apkverify/tests/apkverify_test.rs b/libs/apkverify/tests/apkverify_test.rs
index 0d8e020..441b708 100644
--- a/libs/apkverify/tests/apkverify_test.rs
+++ b/libs/apkverify/tests/apkverify_test.rs
@@ -14,12 +14,14 @@
  * limitations under the License.
  */
 
+use anyhow::Result;
 use apkverify::{
-    get_apk_digest, get_public_key_der, testing::assert_contains, verify, SignatureAlgorithmID,
+    extract_signed_data, get_apk_digest, testing::assert_contains, verify, SignatureAlgorithmID,
 };
 use apkzip::zip_sections;
 use byteorder::{LittleEndian, ReadBytesExt};
 use log::info;
+use openssl::x509::X509;
 use std::fmt::Write;
 use std::io::{Seek, SeekFrom};
 use std::{fs, matches, path::Path};
@@ -286,22 +288,30 @@
 /// * public key extracted from apk without verification
 /// * expected public key from the corresponding .der file
 fn validate_apk_public_key<P: AsRef<Path>>(apk_path: P) {
-    let public_key_from_verification = verify(&apk_path, SDK_INT);
-    let public_key_from_verification =
-        public_key_from_verification.expect("Error in verification result");
+    let signed_data_from_verification =
+        verify(&apk_path, SDK_INT).expect("Error in verification result");
+    let cert_from_verification = signed_data_from_verification.first_certificate_der().unwrap();
+    let public_key_from_verification = public_key_der_from_cert(cert_from_verification).unwrap();
 
     let expected_public_key_path = format!("{}.der", apk_path.as_ref().to_str().unwrap());
     assert_bytes_eq_to_data_in_file(&public_key_from_verification, expected_public_key_path);
 
-    let public_key_from_apk = get_public_key_der(&apk_path, SDK_INT);
-    let public_key_from_apk =
-        public_key_from_apk.expect("Error when extracting public key from apk");
+    let signed_data_from_apk = extract_signed_data(&apk_path, SDK_INT)
+        .expect("Error when extracting signed data from apk");
+    let cert_from_apk = signed_data_from_apk.first_certificate_der().unwrap();
+    // If the two certficiates are byte for byte identical (which they should be), then so are
+    // the public keys embedded in them.
     assert_eq!(
-        public_key_from_verification, public_key_from_apk,
-        "Public key extracted directly from apk does not match the public key from verification."
+        cert_from_verification, cert_from_apk,
+        "Certificate extracted directly from apk does not match the certificate from verification."
     );
 }
 
+fn public_key_der_from_cert(cert_der: &[u8]) -> Result<Vec<u8>> {
+    let cert = X509::from_der(cert_der)?;
+    Ok(cert.public_key()?.public_key_to_der()?)
+}
+
 /// Validates that the following apk_digest are equal:
 /// * apk_digest directly extracted from apk without computation
 /// * computed apk_digest