diff --git a/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/impl/CertificateGenerator.java b/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/impl/CertificateGenerator.java
index e0c999ad071..7a2538af224 100755
--- a/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/impl/CertificateGenerator.java
+++ b/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/impl/CertificateGenerator.java
@@ -64,7 +64,6 @@ import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
-import java.math.BigInteger;
 import java.security.InvalidKeyException;
 import java.security.KeyFactory;
 import java.security.KeyPair;
@@ -158,10 +157,9 @@ public class CertificateGenerator {
             keyPairGenerator.initialize(ConfigurationUtil.RSA_KEY_LENGTH, new SecureRandom());
             KeyPair pair = keyPairGenerator.generateKeyPair();
             X500Principal principal = new X500Principal(ConfigurationUtil.DEFAULT_PRINCIPAL);
-            BigInteger serial = BigInteger.valueOf(System.currentTimeMillis());
 
             X509v3CertificateBuilder certificateBuilder = new JcaX509v3CertificateBuilder(
-                    principal, serial, validityBeginDate, validityEndDate,
+                    principal, CommonUtil.generateSerialNumber(), validityBeginDate, validityEndDate,
                     principal, pair.getPublic());
             ContentSigner contentSigner = new JcaContentSignerBuilder(ConfigurationUtil.SHA256_RSA)
                     .setProvider(ConfigurationUtil.PROVIDER).build(
@@ -285,9 +283,14 @@ public class CertificateGenerator {
     }
 
     public boolean verifySignature(String headerSignature) throws KeystoreException {
+        Certificate certificate = extractCertificateFromSignature(headerSignature);
+        return  (certificate != null);
+    }
+
+    public X509Certificate extractCertificateFromSignature(String headerSignature) throws KeystoreException {
 
         if (headerSignature == null || headerSignature.isEmpty()) {
-            return false;
+            return null;
         }
 
         try {
@@ -308,8 +311,8 @@ public class CertificateGenerator {
                     Certificate lookUpCertificate = keyStoreReader.getCertificateByAlias(
                             reqCert.getSerialNumber().toString());
 
-                    if (lookUpCertificate != null) {
-                        return true;
+                    if (lookUpCertificate != null && (lookUpCertificate instanceof X509Certificate)) {
+                        return (X509Certificate)lookUpCertificate;
                     }
                 }
 
@@ -328,7 +331,7 @@ public class CertificateGenerator {
             throw new KeystoreException(errorMsg, e);
         }
 
-        return false;
+        return null;
     }
 
     public X509Certificate generateCertificateFromCSR(PrivateKey privateKey,
@@ -353,7 +356,7 @@ public class CertificateGenerator {
         }
 
         X509v3CertificateBuilder certificateBuilder = new X509v3CertificateBuilder(
-                new X500Name(issueSubject), BigInteger.valueOf(System.currentTimeMillis()),
+                new X500Name(issueSubject), CommonUtil.generateSerialNumber(),
                 validityBeginDate, validityEndDate, certSubject, request.getSubjectPublicKeyInfo());
 
         ContentSigner sigGen;
diff --git a/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementService.java b/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementService.java
index 67171a3f93d..0b47c43707f 100644
--- a/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementService.java
+++ b/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementService.java
@@ -49,4 +49,6 @@ public interface CertificateManagementService {
     Certificate getCertificateByAlias(String alias) throws KeystoreException;
 
     boolean verifySignature(String headerSignature) throws KeystoreException;
+
+    public X509Certificate extractCertificateFromSignature(String headerSignature) throws KeystoreException;
 }
diff --git a/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementServiceImpl.java b/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementServiceImpl.java
index 014363e90d9..c379df42646 100644
--- a/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementServiceImpl.java
+++ b/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementServiceImpl.java
@@ -92,4 +92,8 @@ public class CertificateManagementServiceImpl implements CertificateManagementSe
     public boolean verifySignature(String headerSignature) throws KeystoreException {
         return certificateGenerator.verifySignature(headerSignature);
     }
+
+    public X509Certificate extractCertificateFromSignature(String headerSignature) throws KeystoreException {
+        return certificateGenerator.extractCertificateFromSignature(headerSignature);
+    }
 }
diff --git a/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/util/CommonUtil.java b/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/util/CommonUtil.java
index a149c925698..6b9bc5897e0 100755
--- a/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/util/CommonUtil.java
+++ b/components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/util/CommonUtil.java
@@ -17,6 +17,7 @@
  */
 package org.wso2.carbon.certificate.mgt.core.util;
 
+import java.math.BigInteger;
 import java.util.Calendar;
 import java.util.Date;
 
@@ -40,4 +41,8 @@ public class CommonUtil {
         return calendar.getTime();
     }
 
+    public static synchronized BigInteger generateSerialNumber() {
+        return BigInteger.valueOf(System.currentTimeMillis());
+    }
+
 }
diff --git a/components/webapp-authenticator-framework/org.wso2.carbon.webapp.authenticator.framework/pom.xml b/components/webapp-authenticator-framework/org.wso2.carbon.webapp.authenticator.framework/pom.xml
index 34051486391..edca5ac9554 100644
--- a/components/webapp-authenticator-framework/org.wso2.carbon.webapp.authenticator.framework/pom.xml
+++ b/components/webapp-authenticator-framework/org.wso2.carbon.webapp.authenticator.framework/pom.xml
@@ -88,7 +88,11 @@
                             org.wso2.carbon.user.core.tenant,
                             org.wso2.carbon.utils,
                             org.wso2.carbon.utils.multitenancy,
-                            org.xml.sax
+                            org.xml.sax,
+                            javax.servlet.http,
+                            javax.xml,
+                            org.apache.axis2.transport.http,
+                            org.wso2.carbon.apimgt.impl
                         </Import-Package>
                         <!--<Fragment-Host>tomcat</Fragment-Host>-->
                     </instructions>