diff --git a/src/platform/java/org/conscrypt/CertBlacklist.java b/src/platform/java/org/conscrypt/CertBlacklist.java
new file mode 100644
index 0000000..56ddb65
--- /dev/null
+++ b/src/platform/java/org/conscrypt/CertBlacklist.java
@@ -0,0 +1,251 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+package org.conscrypt;
+
+import java.io.Closeable;
+import java.io.ByteArrayOutputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.math.BigInteger;
+import java.security.GeneralSecurityException;
+import java.security.MessageDigest;
+import java.security.PublicKey;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class CertBlacklist {
+    private static final Logger logger = Logger.getLogger(CertBlacklist.class.getName());
+
+    // public for testing
+    public final Set<BigInteger> serialBlacklist;
+    public final Set<byte[]> pubkeyBlacklist;
+
+    public CertBlacklist() {
+        String androidData = System.getenv("ANDROID_DATA");
+        String blacklistRoot = androidData + "/misc/keychain/";
+        String defaultPubkeyBlacklistPath = blacklistRoot + "pubkey_blacklist.txt";
+        String defaultSerialBlacklistPath = blacklistRoot + "serial_blacklist.txt";
+
+        pubkeyBlacklist = readPublicKeyBlackList(defaultPubkeyBlacklistPath);
+        serialBlacklist = readSerialBlackList(defaultSerialBlacklistPath);
+    }
+
+    /** Test only interface, not for public use */
+    public CertBlacklist(String pubkeyBlacklistPath, String serialBlacklistPath) {
+        pubkeyBlacklist = readPublicKeyBlackList(pubkeyBlacklistPath);
+        serialBlacklist = readSerialBlackList(serialBlacklistPath);
+    }
+
+    private static boolean isHex(String value) {
+        try {
+            new BigInteger(value, 16);
+            return true;
+        } catch (NumberFormatException e) {
+            logger.log(Level.WARNING, "Could not parse hex value " + value, e);
+            return false;
+        }
+    }
+
+    private static boolean isPubkeyHash(String value) {
+        if (value.length() != 40) {
+            logger.log(Level.WARNING, "Invalid pubkey hash length: " + value.length());
+            return false;
+        }
+        return isHex(value);
+    }
+
+    private static String readBlacklist(String path) {
+        try {
+            return readFileAsString(path);
+        } catch (FileNotFoundException ignored) {
+        } catch (IOException e) {
+            logger.log(Level.WARNING, "Could not read blacklist", e);
+        }
+        return "";
+    }
+
+    // From IoUtils.readFileAsString
+    private static String readFileAsString(String path) throws IOException {
+        return readFileAsBytes(path).toString("UTF-8");
+    }
+
+    // Based on IoUtils.readFileAsBytes
+    private static ByteArrayOutputStream readFileAsBytes(String path) throws IOException {
+        RandomAccessFile f = null;
+        try {
+            f = new RandomAccessFile(path, "r");
+            ByteArrayOutputStream bytes = new ByteArrayOutputStream((int) f.length());
+            byte[] buffer = new byte[8192];
+            while (true) {
+                int byteCount = f.read(buffer);
+                if (byteCount == -1) {
+                    return bytes;
+                }
+                bytes.write(buffer, 0, byteCount);
+            }
+        } finally {
+            closeQuietly(f);
+        }
+    }
+
+    // Base on IoUtils.closeQuietly
+    private static void closeQuietly(Closeable closeable) {
+        if (closeable != null) {
+            try {
+                closeable.close();
+            } catch (RuntimeException rethrown) {
+                throw rethrown;
+            } catch (Exception ignored) {
+            }
+        }
+    }
+
+    private static final Set<BigInteger> readSerialBlackList(String path) {
+
+        /* Start out with a base set of known bad values.
+         *
+         * WARNING: Do not add short serials to this list!
+         *
+         * Since this currently doesn't compare the serial + issuer, you
+         * should only add serials that have enough entropy here. Short
+         * serials may inadvertently match a certificate that was issued
+         * not in compliance with the Baseline Requirements.
+         */
+        Set<BigInteger> bl = new HashSet<BigInteger>(Arrays.asList(
+            // From http://src.chromium.org/viewvc/chrome/trunk/src/net/base/x509_certificate.cc?revision=78748&view=markup
+            // Not a real certificate. For testing only.
+            new BigInteger("077a59bcd53459601ca6907267a6dd1c", 16),
+            new BigInteger("047ecbe9fca55f7bd09eae36e10cae1e", 16),
+            new BigInteger("d8f35f4eb7872b2dab0692e315382fb0", 16),
+            new BigInteger("b0b7133ed096f9b56fae91c874bd3ac0", 16),
+            new BigInteger("9239d5348f40d1695a745470e1f23f43", 16),
+            new BigInteger("e9028b9578e415dc1a710a2b88154447", 16),
+            new BigInteger("d7558fdaf5f1105bb213282b707729a3", 16),
+            new BigInteger("f5c86af36162f13a64f54f6dc9587c06", 16),
+            new BigInteger("392a434f0e07df1f8aa305de34e0c229", 16),
+            new BigInteger("3e75ced46b693021218830ae86a82a71", 16)
+        ));
+
+        // attempt to augment it with values taken from gservices
+        String serialBlacklist = readBlacklist(path);
+        if (!serialBlacklist.equals("")) {
+            for(String value : serialBlacklist.split(",")) {
+                try {
+                    bl.add(new BigInteger(value, 16));
+                } catch (NumberFormatException e) {
+                    logger.log(Level.WARNING, "Tried to blacklist invalid serial number " + value, e);
+                }
+            }
+        }
+
+        // whether that succeeds or fails, send it on its merry way
+        return Collections.unmodifiableSet(bl);
+    }
+
+    private static final Set<byte[]> readPublicKeyBlackList(String path) {
+
+        // start out with a base set of known bad values
+        Set<byte[]> bl = new HashSet<byte[]>(Arrays.asList(
+            // From http://src.chromium.org/viewvc/chrome/branches/782/src/net/base/x509_certificate.cc?r1=98750&r2=98749&pathrev=98750
+            // C=NL, O=DigiNotar, CN=DigiNotar Root CA/emailAddress=info@diginotar.nl
+            "410f36363258f30b347d12ce4863e433437806a8".getBytes(),
+            // Subject: CN=DigiNotar Cyber CA
+            // Issuer: CN=GTE CyberTrust Global Root
+            "ba3e7bd38cd7e1e6b9cd4c219962e59d7a2f4e37".getBytes(),
+            // Subject: CN=DigiNotar Services 1024 CA
+            // Issuer: CN=Entrust.net
+            "e23b8d105f87710a68d9248050ebefc627be4ca6".getBytes(),
+            // Subject: CN=DigiNotar PKIoverheid CA Organisatie - G2
+            // Issuer: CN=Staat der Nederlanden Organisatie CA - G2
+            "7b2e16bc39bcd72b456e9f055d1de615b74945db".getBytes(),
+            // Subject: CN=DigiNotar PKIoverheid CA Overheid en Bedrijven
+            // Issuer: CN=Staat der Nederlanden Overheid CA
+            "e8f91200c65cee16e039b9f883841661635f81c5".getBytes(),
+            // From http://src.chromium.org/viewvc/chrome?view=rev&revision=108479
+            // Subject: O=Digicert Sdn. Bhd.
+            // Issuer: CN=GTE CyberTrust Global Root
+            "0129bcd5b448ae8d2496d1c3e19723919088e152".getBytes(),
+            // Subject: CN=e-islem.kktcmerkezbankasi.org/emailAddress=ileti@kktcmerkezbankasi.org
+            // Issuer: CN=T\xC3\x9CRKTRUST Elektronik Sunucu Sertifikas\xC4\xB1 Hizmetleri
+            "5f3ab33d55007054bc5e3e5553cd8d8465d77c61".getBytes(),
+            // Subject: CN=*.EGO.GOV.TR 93
+            // Issuer: CN=T\xC3\x9CRKTRUST Elektronik Sunucu Sertifikas\xC4\xB1 Hizmetleri
+            "783333c9687df63377efceddd82efa9101913e8e".getBytes(),
+            // Subject: Subject: C=FR, O=DG Tr\xC3\xA9sor, CN=AC DG Tr\xC3\xA9sor SSL
+            // Issuer: C=FR, O=DGTPE, CN=AC DGTPE Signature Authentification
+            "3ecf4bbbe46096d514bb539bb913d77aa4ef31bf".getBytes()
+        ));
+
+        // attempt to augment it with values taken from gservices
+        String pubkeyBlacklist = readBlacklist(path);
+        if (!pubkeyBlacklist.equals("")) {
+            for (String value : pubkeyBlacklist.split(",")) {
+                value = value.trim();
+                if (isPubkeyHash(value)) {
+                    bl.add(value.getBytes());
+                } else {
+                    logger.log(Level.WARNING, "Tried to blacklist invalid pubkey " + value);
+                }
+            }
+        }
+
+        return bl;
+    }
+
+    public boolean isPublicKeyBlackListed(PublicKey publicKey) {
+        byte[] encoded = publicKey.getEncoded();
+        MessageDigest md;
+        try {
+            md = MessageDigest.getInstance("SHA1");
+        } catch (GeneralSecurityException e) {
+            logger.log(Level.SEVERE, "Unable to get SHA1 MessageDigest", e);
+            return false;
+        }
+        byte[] out = toHex(md.digest(encoded));
+        for (byte[] blacklisted : pubkeyBlacklist) {
+            if (Arrays.equals(blacklisted, out)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private static final byte[] HEX_TABLE = { (byte) '0', (byte) '1', (byte) '2', (byte) '3',
+        (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) 'a',
+        (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f'};
+
+    private static final byte[] toHex(byte[] in) {
+        byte[] out = new byte[in.length * 2];
+        int outIndex = 0;
+        for (int i = 0; i < in.length; i++) {
+            int value = in[i] & 0xff;
+            out[outIndex++] = HEX_TABLE[value >> 4];
+            out[outIndex++] = HEX_TABLE[value & 0xf];
+        }
+        return out;
+    }
+
+    public boolean isSerialNumberBlackListed(BigInteger serial) {
+        return serialBlacklist.contains(serial);
+    }
+
+}
diff --git a/src/platform/java/org/conscrypt/TrustManagerImpl.java b/src/platform/java/org/conscrypt/TrustManagerImpl.java
index 8ee9b28..dc7882e 100644
--- a/src/platform/java/org/conscrypt/TrustManagerImpl.java
+++ b/src/platform/java/org/conscrypt/TrustManagerImpl.java
@@ -107,6 +107,7 @@
 
     private final Exception err;
     private final CertificateFactory factory;
+    private final CertBlacklist blacklist;
 
     /**
      * Creates X509TrustManager based on a keystore
@@ -129,6 +130,15 @@
      */
     public TrustManagerImpl(KeyStore keyStore, CertPinManager manager,
                             TrustedCertificateStore certStore) {
+        this(keyStore, manager, certStore, null);
+    }
+
+    /**
+     * For testing only.
+     */
+    public TrustManagerImpl(KeyStore keyStore, CertPinManager manager,
+                            TrustedCertificateStore certStore,
+                            CertBlacklist blacklist) {
         CertPathValidator validatorLocal = null;
         CertificateFactory factoryLocal = null;
         KeyStore rootKeyStoreLocal = null;
@@ -169,6 +179,10 @@
             }
         }
 
+        if (blacklist == null) {
+            blacklist = new CertBlacklist();
+        }
+
         this.rootKeyStore = rootKeyStoreLocal;
         this.trustedCertificateStore = trustedCertificateStoreLocal;
         this.validator = validatorLocal;
@@ -177,6 +191,7 @@
         this.intermediateIndex = new TrustedCertificateIndex();
         this.acceptedIssuers = acceptedIssuersLocal;
         this.err = errLocal;
+        this.blacklist = blacklist;
     }
 
     private static X509Certificate[] acceptedIssuers(KeyStore ks) {
@@ -421,6 +436,9 @@
             current = trustAnchorChain.get(trustAnchorChain.size() - 1).getTrustedCert();
         }
 
+        // Check that the certificate isn't blacklisted.
+        checkBlacklist(current);
+
         // 1. If the current certificate in the chain is self-signed verify the chain as is.
         if (current.getIssuerDN().equals(current.getSubjectDN())) {
             return verifyChain(untrustedChain, trustAnchorChain, host, clientAuth);
@@ -564,6 +582,10 @@
                         "Certificate path is not properly pinned.", null, certPath, -1));
             }
         }
+        // Check whole chain against the blacklist
+        for (X509Certificate cert : wholeChain) {
+            checkBlacklist(cert);
+        }
 
         if (untrustedChain.isEmpty()) {
             // The chain consists of only trust anchors, skip the validator
@@ -596,6 +618,12 @@
         return wholeChain;
     }
 
+    private void checkBlacklist(X509Certificate cert) throws CertificateException {
+        if (blacklist.isPublicKeyBlackListed(cert.getPublicKey())) {
+            throw new CertificateException("Certificate blacklisted by public key: " + cert);
+        }
+    }
+
     /**
      * Sort potential anchors so that the most preferred for use come first.
      *