Add the logic to save device id to certificate DB

partialy fixes https://roadmap.entgra.net/issues/10145

components/certificate-mgt/io.entgra.device.mgt.core.certificate.mgt.core/src/main/java/io/entgra/device/mgt/core/certificate/mgt/core/bean/Certificate.java

@@ -25,6 +25,15 @@ public class Certificate {
     X509Certificate certificate;
     int tenantId;
     String tenantDomain;
+    String deviceIdentifier;
+
+    public String getDeviceIdentifier() {
+        return deviceIdentifier;
+    }
+
+    public void setDeviceIdentifier(String deviceIdentifier) {
+        this.deviceIdentifier = deviceIdentifier;
+    }
 
     public int getTenantId() {
         return tenantId;

components/certificate-mgt/io.entgra.device.mgt.core.certificate.mgt.core/src/main/java/io/entgra/device/mgt/core/certificate/mgt/core/dao/CertificateDAO.java

@@ -41,6 +41,17 @@ public interface CertificateDAO {
     void addCertificate(List<Certificate> certificate)
             throws CertificateManagementDAOException;
 
+    /**
+     * This can be used to store a certificate in the database, where it will be stored against the serial number
+     * of the certificate.
+     *
+     * @param certificate Holds the certificate and relevant details.
+     * @throws CertificateManagementDAOException
+     *
+     */
+    void addCertificate(Certificate certificate)
+            throws CertificateManagementDAOException;
+
     /**
      * Usage is to obtain a certificate stored in the database by providing the common name.
      *

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

@@ -81,6 +81,40 @@ public abstract class AbstractCertificateDAOImpl implements CertificateDAO{
         }
     }
 
+    @Override
+    public void addCertificate(Certificate certificate)
+            throws CertificateManagementDAOException {
+        Connection conn;
+        PreparedStatement stmt = null;
+        try {
+            conn = this.getConnection();
+            stmt = conn.prepareStatement(
+                    "INSERT INTO DM_DEVICE_CERTIFICATE (SERIAL_NUMBER, CERTIFICATE, TENANT_ID," +
+                            " USERNAME, DEVICE_IDENTIFIER) VALUES (?,?,?,?,?)");
+            PrivilegedCarbonContext threadLocalCarbonContext = PrivilegedCarbonContext.
+                    getThreadLocalCarbonContext();
+            String username = threadLocalCarbonContext.getUsername();
+            // the serial number of the certificate used for its creation is set as its alias.
+            String serialNumber = certificate.getSerial();
+            if (serialNumber == null || serialNumber.isEmpty()) {
+                serialNumber = String.valueOf(certificate.getCertificate().getSerialNumber());
+            }
+            byte[] bytes = Serializer.serialize(certificate.getCertificate());
+
+            stmt.setString(1, serialNumber);
+            stmt.setBytes(2, bytes);
+            stmt.setInt(3, certificate.getTenantId());
+            stmt.setString(4, username);
+            stmt.setString(5, certificate.getDeviceIdentifier());
+            stmt.executeUpdate();
+        } catch (SQLException | IOException e) {
+            throw new CertificateManagementDAOException("Error occurred while saving the " +
+                    "certificate. ", e);
+        } finally {
+            CertificateManagementDAOUtil.cleanupResources(stmt, null);
+        }
+    }
+
     @Override
     public CertificateResponse retrieveCertificate(String serialNumber)
             throws CertificateManagementDAOException {

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

@@ -727,6 +727,29 @@ public class CertificateGenerator {
             throw new KeystoreException(errorMsg, e);
         }
     }
+    public void saveCertificate(org.wso2.carbon.certificate.mgt.core.bean.Certificate
+                                     certificate) throws KeystoreException {
+
+        if (certificate == null) {
+            return;
+        }
+
+        try {
+            CertificateDAO certificateDAO = CertificateManagementDAOFactory.getCertificateDAO();
+            CertificateManagementDAOFactory.beginTransaction();
+            certificateDAO.addCertificate(certificate);
+            CertificateManagementDAOFactory.commitTransaction();
+        } catch (CertificateManagementDAOException e) {
+            String errorMsg = "Error occurred when saving the generated certificate in database";
+            log.error(errorMsg);
+            CertificateManagementDAOFactory.rollbackTransaction();
+            throw new KeystoreException(errorMsg, e);
+        } catch (TransactionManagementException e) {
+            String errorMsg = "Error occurred when saving the generated certificate in database";
+            log.error(errorMsg);
+            throw new KeystoreException(errorMsg, e);
+        }
+    }
 
     public void saveCertInKeyStore(List<io.entgra.device.mgt.core.certificate.mgt.core.bean.Certificate> certificate)
             throws KeystoreException {
@@ -866,8 +889,8 @@ public class CertificateGenerator {
             List<io.entgra.device.mgt.core.certificate.mgt.core.bean.Certificate> certificates = new ArrayList<>();
             certificate.setTenantId(PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId());
             certificate.setCertificate(issuedCert);
-            certificates.add(certificate);
+            certificate.setDeviceIdentifier(commonName);
-            saveCertInKeyStore(certificates);
+            saveCertificate(certificate);
 
         } catch (OperatorCreationException e) {
             String errorMsg = "Error creating the content signer";