Hibernate Encryption of Database Completely Transparent to Application

Question

I\'m working on a Grails 1.0.4 project that has to be released in less than 2 weeks, and the customer just came up with a requirement that all data in the database should be enc

Answer 1

If you end doing the work in the application, you can use Hibernate custom types and it wouldn't add that many changes to your code.

Here's an encrypted string custom type that I've used:

import org.hibernate.usertype.UserType
import org.apache.log4j.Logger

import java.sql.PreparedStatement
import java.sql.ResultSet
import java.sql.SQLException
import java.sql.Types

class EncryptedString implements UserType {

  // prefix category name with 'org.hibernate.type' to make logging of all types easier
  private final Logger _log = Logger.getLogger('org.hibernate.type.com.yourcompany.EncryptedString')

  Object nullSafeGet(ResultSet rs, String[] names, Object owner) throws SQLException {
    String value = rs.getString(names[0])

    if (!value) {
      _log.trace "returning null as column: $names[0]"
      return null
    }

    _log.trace "returning '$value' as column: $names[0]"
    return CryptoUtils.decrypt(value)
  }

  void nullSafeSet(PreparedStatement st, Object value, int index) throws SQLException {
    if (value) {
      String encrypted = CryptoUtils.encrypt(value.toString())
      _log.trace "binding '$encrypted' to parameter: $index"
      st.setString index, encrypted
    }
    else {
      _log.trace "binding null to parameter: $index"
      st.setNull(index, Types.VARCHAR)
    }
  }

  Class returnedClass() { String }

  int[] sqlTypes() { [Types.VARCHAR] as int[] }

  Object assemble(Serializable cached, Object owner) { cached.toString() }

  Object deepCopy(Object value) { value.toString() }

  Serializable disassemble(Object value) { value.toString() }

  boolean equals(Object x, Object y) { x == y }

  int hashCode(Object x) { x.hashCode() }

  boolean isMutable() { true }

  Object replace(Object original, Object target, Object owner) { original }
}

and based on this it should be simple to create similar classes for int, long, etc. To use it, add the type to the mapping closure:

class MyDomainClass {

  String name
  String otherField

  static mapping = {
    name type: EncryptedString
    otherField type: EncryptedString
  }
}

I omitted the CryptoUtils.encrypt() and CryptoUtils.decrypt() methods since that's not Grails-specific. We're using AES, e.g. "Cipher cipher = Cipher.getInstance('AES/CBC/PKCS5Padding')". Whatever you end up using, make sure it's a 2-way crypto, i.e. don't use SHA-256.