Validate email address when adding email or creating account

This checks that the email address has a valid format.

Change-Id: I1f8d95dd9b02e720996bd15cca093ca55b5e4597
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-server/src/main/java/com/google/gerrit/server/account/CreateEmail.java

@@ -35,6 +35,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.assistedinject.Assisted;
 
+import org.apache.commons.validator.routines.EmailValidator;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -99,6 +100,10 @@ public class CreateEmail implements RestModifyView<AccountResource, Input> {
       throw new BadRequestException("email address must match URL");
     }
 
+    if (!EmailValidator.getInstance().isValid(email)) {
+      throw new BadRequestException("invalid email address");
+    }
+
     if (input.noConfirmation
         && !self.get().getCapabilities().canAdministrateServer()) {
       throw new AuthException("must be administrator to use no_confirmation");