Add SCEP support

fixes https://roadmap.entgra.net/issues/10042

components/certificate-mgt/io.entgra.device.mgt.core.certificate.mgt.core/src/main/java/io/entgra/device/mgt/core/certificate/mgt/core/impl/CertificateGenerator.java

@@ -55,10 +55,28 @@ import org.bouncycastle.operator.OperatorCreationException;
 import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
 import org.bouncycastle.pkcs.PKCS10CertificationRequest;
 import org.bouncycastle.util.Store;
-import org.jscep.message.*;
+import org.jscep.message.CertRep;
+import org.jscep.message.MessageDecodingException;
+import org.jscep.message.MessageEncodingException;
+import org.jscep.message.PkcsPkiEnvelopeDecoder;
+import org.jscep.message.PkcsPkiEnvelopeEncoder;
+import org.jscep.message.PkiMessage;
+import org.jscep.message.PkiMessageDecoder;
+import org.jscep.message.PkiMessageEncoder;
 import org.jscep.transaction.FailInfo;
 import org.jscep.transaction.Nonce;
 import org.jscep.transaction.TransactionId;
+import org.wso2.carbon.certificate.mgt.core.dao.CertificateDAO;
+import org.wso2.carbon.certificate.mgt.core.dao.CertificateManagementDAOException;
+import org.wso2.carbon.certificate.mgt.core.dao.CertificateManagementDAOFactory;
+import org.wso2.carbon.certificate.mgt.core.dto.CAStatus;
+import org.wso2.carbon.certificate.mgt.core.dto.CertificateResponse;
+import org.wso2.carbon.certificate.mgt.core.dto.SCEPResponse;
+import org.wso2.carbon.certificate.mgt.core.exception.KeystoreException;
+import org.wso2.carbon.certificate.mgt.core.exception.TransactionManagementException;
+import org.wso2.carbon.certificate.mgt.core.util.CertificateManagementConstants;
+import org.wso2.carbon.certificate.mgt.core.util.CommonUtil;
+import org.wso2.carbon.certificate.mgt.core.util.Serializer;
 import org.wso2.carbon.context.PrivilegedCarbonContext;
 
 import javax.naming.InvalidNameException;
@@ -70,12 +88,35 @@ import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.math.BigInteger;
-import java.security.*;
+import java.security.InvalidKeyException;
+import java.security.KeyFactory;
+import java.security.KeyPair;
+import java.security.KeyPairGenerator;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+import java.security.SecureRandom;
+import java.security.Security;
+import java.security.SignatureException;
 import java.security.cert.Certificate;
 import java.security.cert.*;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.X509EncodedKeySpec;
 import java.util.*;
+import java.security.cert.CertificateEncodingException;
+import java.security.cert.CertificateException;
+import java.security.cert.CertificateExpiredException;
+import java.security.cert.CertificateFactory;
+import java.security.cert.CertificateNotYetValidException;
+import java.security.cert.X509Certificate;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.X509EncodedKeySpec;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Date;
+import java.util.List;
+>>>>>>> dfe957b019 (Add SCEP support):components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/impl/CertificateGenerator.java
 import java.util.concurrent.TimeUnit;
 
 public class CertificateGenerator {
@@ -773,6 +814,7 @@ public class CertificateGenerator {
 
             BigInteger serialNumber = BigInteger.valueOf(System.currentTimeMillis());
 
+<<<<<<< HEAD:components/certificate-mgt/io.entgra.device.mgt.core.certificate.mgt.core/src/main/java/io/entgra/device/mgt/core/certificate/mgt/core/impl/CertificateGenerator.java
             //Reversing the order of components of the subject DN due to Nginx not verifying the client certificate
             //generated by Java using this subject DN.
             //Ref: https://stackoverflow.com/questions/33769978 & engineering mail SCEP implementation for Android
@@ -783,6 +825,10 @@ public class CertificateGenerator {
             }
             String subjectDn = joiner.toString();
             X500Name issuerName = new X500Name(subjectDn);
+=======
+            X500Name issuerName = new X500Name(certCA.getSubjectDN().getName());
+
+>>>>>>> dfe957b019 (Add SCEP support):components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/impl/CertificateGenerator.java
             String commonName = certificationRequest.getSubject().getRDNs(BCStyle.CN)[0].getFirst()
                     .getValue().toString();
             X500Name subjectName = new X500Name("O=" + commonName + "O=AndroidDevice,CN=" +