security.groovy

security.groovy

// http://docs.oracle.com/javase/6/docs/technotes/guides/security/crypto/CryptoSpec.html

// MessageDisgest
//   - Take input text/bytes and produce a fixe length digest
//   - MD5, MD2, msgDigest-1
// 
// Cipher
//   - Take cleartext text and key and produce a ciphertext
//   - Symmetric uses secret key (fast): DES, 3DES are fixed key length
//   - Asysmmetric uses public/private key (slow): AES, RSA are variable length
// 

// Print list of all available algorithms from providers
//java.security.Security.providers.each{p->p.getServices().each{s->println s}}

/*// MessageDigest example
import java.security.*
def msgDigest = MessageDigest.getInstance("MD5")
def inputBytes = "Hello World!".getBytes("UTF-8")
msgDigest.update(inputBytes)
def hashBytes = msgDigest.digest();
hashBytes.each{b->printf("%X",b)}
println()*/

/*// KeyStore examples
import java.security.*
def certFilename = System.getProperty("java.home") + "/lib/security/cacerts"
def password = "changeit"
def keyStore = KeyStore.getInstance("JKS")
new File(certFilename).withInputStream{inStream->
	keyStore.load(inStream, password.toCharArray())
}

// // Print all keyStore alias
// keyStore.aliases().sort().each{a->
// 	def isCert = keyStore.isCertificateEntry(a)
// 	def isKey = keyStore.isKeyEntry(a)
// 	println "$a, cert=$isCert, key=$isKey"
// }

// Get Key or Cert
//def key = keyStore.getKey("mykey", password.toCharArray())
def cert = keyStore.getCertificate("verisignuniversalrootca")
println cert*/

// Cipher example - using custom secret key
import java.security.*
import javax.crypto.*
import javax.crypto.spec.*

def input = "Hello World!"
def secretBytes = "salt and light".getBytes("UTF-8")

def sha = MessageDigest.getInstance("SHA-1")
def keyBytes = sha.digest(secretBytes)
keyBytes = Arrays.copyOf(keyBytes, 16) // use only first 128 bit
def secretKey = new SecretKeySpec(keyBytes, "AES") // or DESede (keySize=24, padSize=8)

// param=transformation => "algorithm/mode/padding" or "algorithm"
def cipher = Cipher.getInstance("AES/ECB/NoPadding")
cipher.init(Cipher.ENCRYPT_MODE, secretKey)
def padSize = 16
def cipherLen = input.length() % padSize
input = input + (" " * (padSize - cipherLen))
def cipherBytes = cipher.doFinal(input.getBytes("UTF-8"))

cipherBytes.each{b->printf("%X",b)}
println()