diff --git a/core/java/android/security/net/config/CertificateSource.java b/core/java/android/security/net/config/CertificateSource.java
index 7e3601e..f3272e4 100644
--- a/core/java/android/security/net/config/CertificateSource.java
+++ b/core/java/android/security/net/config/CertificateSource.java
@@ -16,12 +16,13 @@
 
 package android.security.net.config;
 
-import java.util.Set;
 import java.security.cert.X509Certificate;
+import java.util.Set;
 
 /** @hide */
 public interface CertificateSource {
     Set<X509Certificate> getCertificates();
     X509Certificate findBySubjectAndPublicKey(X509Certificate cert);
     X509Certificate findByIssuerAndSignature(X509Certificate cert);
+    Set<X509Certificate> findAllByIssuerAndSignature(X509Certificate cert);
 }
diff --git a/core/java/android/security/net/config/CertificatesEntryRef.java b/core/java/android/security/net/config/CertificatesEntryRef.java
index ff728ef..742d430 100644
--- a/core/java/android/security/net/config/CertificatesEntryRef.java
+++ b/core/java/android/security/net/config/CertificatesEntryRef.java
@@ -17,8 +17,8 @@
 package android.security.net.config;
 
 import android.util.ArraySet;
-import java.util.Set;
 import java.security.cert.X509Certificate;
+import java.util.Set;
 
 /** @hide */
 public final class CertificatesEntryRef {
@@ -60,4 +60,8 @@
 
         return new TrustAnchor(foundCert, mOverridesPins);
     }
+
+    public Set<X509Certificate> findAllCertificatesByIssuerAndSignature(X509Certificate cert) {
+        return mSource.findAllByIssuerAndSignature(cert);
+    }
 }
diff --git a/core/java/android/security/net/config/DirectoryCertificateSource.java b/core/java/android/security/net/config/DirectoryCertificateSource.java
index bf29efa..b2c068c 100644
--- a/core/java/android/security/net/config/DirectoryCertificateSource.java
+++ b/core/java/android/security/net/config/DirectoryCertificateSource.java
@@ -29,6 +29,7 @@
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
+import java.util.Collections;
 import java.util.Set;
 import libcore.io.IoUtils;
 
@@ -110,10 +111,50 @@
         });
     }
 
+    @Override
+    public Set<X509Certificate> findAllByIssuerAndSignature(final X509Certificate cert) {
+        return findCerts(cert.getIssuerX500Principal(), new CertSelector() {
+            @Override
+            public boolean match(X509Certificate ca) {
+                try {
+                    cert.verify(ca.getPublicKey());
+                    return true;
+                } catch (Exception e) {
+                    return false;
+                }
+            }
+        });
+    }
+
     private static interface CertSelector {
         boolean match(X509Certificate cert);
     }
 
+    private Set<X509Certificate> findCerts(X500Principal subj, CertSelector selector) {
+        String hash = getHash(subj);
+        Set<X509Certificate> certs = null;
+        for (int index = 0; index >= 0; index++) {
+            String fileName = hash + "." + index;
+            if (!new File(mDir, fileName).exists()) {
+                break;
+            }
+            if (isCertMarkedAsRemoved(fileName)) {
+                continue;
+            }
+            X509Certificate cert = readCertificate(fileName);
+            if (!subj.equals(cert.getSubjectX500Principal())) {
+                continue;
+            }
+            if (selector.match(cert)) {
+                if (certs == null) {
+                    certs = new ArraySet<X509Certificate>();
+                }
+                certs.add(cert);
+            }
+        }
+        return certs != null ? certs : Collections.<X509Certificate>emptySet();
+    }
+
     private X509Certificate findCert(X500Principal subj, CertSelector selector) {
         String hash = getHash(subj);
         for (int index = 0; index >= 0; index++) {
diff --git a/core/java/android/security/net/config/KeyStoreCertificateSource.java b/core/java/android/security/net/config/KeyStoreCertificateSource.java
index b6105cd..ba5dd83 100644
--- a/core/java/android/security/net/config/KeyStoreCertificateSource.java
+++ b/core/java/android/security/net/config/KeyStoreCertificateSource.java
@@ -21,6 +21,7 @@
 import java.security.KeyStoreException;
 import java.security.cert.Certificate;
 import java.security.cert.X509Certificate;
+import java.util.Collections;
 import java.util.Enumeration;
 import java.util.Set;
 
@@ -90,4 +91,18 @@
         }
         return anchor.getTrustedCert();
     }
+
+    @Override
+    public Set<X509Certificate> findAllByIssuerAndSignature(X509Certificate cert) {
+        ensureInitialized();
+        Set<java.security.cert.TrustAnchor> anchors = mIndex.findAllByIssuerAndSignature(cert);
+        if (anchors.isEmpty()) {
+            return Collections.<X509Certificate>emptySet();
+        }
+        Set<X509Certificate> certs = new ArraySet<X509Certificate>(anchors.size());
+        for (java.security.cert.TrustAnchor anchor : anchors) {
+            certs.add(anchor.getTrustedCert());
+        }
+        return certs;
+    }
 }
diff --git a/core/java/android/security/net/config/NetworkSecurityConfig.java b/core/java/android/security/net/config/NetworkSecurityConfig.java
index 0a2edff..ebe14691 100644
--- a/core/java/android/security/net/config/NetworkSecurityConfig.java
+++ b/core/java/android/security/net/config/NetworkSecurityConfig.java
@@ -145,6 +145,15 @@
         return null;
     }
 
+    /** @hide */
+    public Set<X509Certificate> findAllCertificatesByIssuerAndSignature(X509Certificate cert) {
+        Set<X509Certificate> certs = new ArraySet<X509Certificate>();
+        for (CertificatesEntryRef ref : mCertificatesEntryRefs) {
+            certs.addAll(ref.findAllCertificatesByIssuerAndSignature(cert));
+        }
+        return certs;
+    }
+
     /**
      * Return a {@link Builder} for the default {@code NetworkSecurityConfig}.
      *
diff --git a/core/java/android/security/net/config/ResourceCertificateSource.java b/core/java/android/security/net/config/ResourceCertificateSource.java
index e489c2c..8803c4b 100644
--- a/core/java/android/security/net/config/ResourceCertificateSource.java
+++ b/core/java/android/security/net/config/ResourceCertificateSource.java
@@ -25,6 +25,7 @@
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Set;
 
 import com.android.org.conscrypt.TrustedCertificateIndex;
@@ -100,4 +101,18 @@
         }
         return anchor.getTrustedCert();
     }
+
+    @Override
+    public Set<X509Certificate> findAllByIssuerAndSignature(X509Certificate cert) {
+        ensureInitialized();
+        Set<java.security.cert.TrustAnchor> anchors = mIndex.findAllByIssuerAndSignature(cert);
+        if (anchors.isEmpty()) {
+            return Collections.<X509Certificate>emptySet();
+        }
+        Set<X509Certificate> certs = new ArraySet<X509Certificate>(anchors.size());
+        for (java.security.cert.TrustAnchor anchor : anchors) {
+            certs.add(anchor.getTrustedCert());
+        }
+        return certs;
+    }
 }
diff --git a/core/java/android/security/net/config/TrustedCertificateStoreAdapter.java b/core/java/android/security/net/config/TrustedCertificateStoreAdapter.java
index 4a90f82..c2f29be 100644
--- a/core/java/android/security/net/config/TrustedCertificateStoreAdapter.java
+++ b/core/java/android/security/net/config/TrustedCertificateStoreAdapter.java
@@ -42,6 +42,11 @@
     }
 
     @Override
+    public Set<X509Certificate> findAllIssuers(X509Certificate cert) {
+        return mConfig.findAllCertificatesByIssuerAndSignature(cert);
+    }
+
+    @Override
     public X509Certificate getTrustAnchor(X509Certificate cert) {
         TrustAnchor anchor = mConfig.findTrustAnchorBySubjectAndPublicKey(cert);
         if (anchor == null) {
diff --git a/tests/NetworkSecurityConfigTest/src/android/security/net/config/TestCertificateSource.java b/tests/NetworkSecurityConfigTest/src/android/security/net/config/TestCertificateSource.java
index 0c36063..4c12c2d 100644
--- a/tests/NetworkSecurityConfigTest/src/android/security/net/config/TestCertificateSource.java
+++ b/tests/NetworkSecurityConfigTest/src/android/security/net/config/TestCertificateSource.java
@@ -16,8 +16,9 @@
 
 package android.security.net.config;
 
-import java.util.Set;
+import android.util.ArraySet;
 import java.security.cert.X509Certificate;
+import java.util.Set;
 
 import com.android.org.conscrypt.TrustedCertificateIndex;
 
@@ -33,10 +34,12 @@
         }
     }
 
+    @Override
     public Set<X509Certificate> getCertificates() {
             return mCertificates;
     }
 
+    @Override
     public X509Certificate findBySubjectAndPublicKey(X509Certificate cert) {
         java.security.cert.TrustAnchor anchor = mIndex.findBySubjectAndPublicKey(cert);
         if (anchor == null) {
@@ -45,6 +48,7 @@
         return anchor.getTrustedCert();
     }
 
+    @Override
     public X509Certificate findByIssuerAndSignature(X509Certificate cert) {
         java.security.cert.TrustAnchor anchor = mIndex.findByIssuerAndSignature(cert);
         if (anchor == null) {
@@ -52,4 +56,13 @@
         }
         return anchor.getTrustedCert();
     }
+
+    @Override
+    public Set<X509Certificate> findAllByIssuerAndSignature(X509Certificate cert) {
+        Set<X509Certificate> certs = new ArraySet<X509Certificate>();
+        for (java.security.cert.TrustAnchor anchor : mIndex.findAllByIssuerAndSignature(cert)) {
+            certs.add(anchor.getTrustedCert());
+        }
+        return certs;
+    }
 }