Make JceMasterKey Case Insensitive (#62)

* Make JceMasterKey Case Insensitive

Algorithm names in the JCA spec are not case-sensitive. This makes
JceMasterKey algorithm names case insensitive. Adds a test for
JceMasterKey getInstance to ensure that the method is case
insensitive.

Author: johnwalker

.gitignore

@@ -4,3 +4,4 @@ target/
 .project
 .classpath
 /bin/
+.idea/

src/main/java/com/amazonaws/encryptionsdk/jce/JceMasterKey.java

@@ -75,8 +75,8 @@ public abstract class JceMasterKey extends MasterKey<JceMasterKey> {
      */
     public static JceMasterKey getInstance(final SecretKey key, final String provider, final String keyId,
             final String wrappingAlgorithm) {
-        switch (wrappingAlgorithm) {
-            case "AES/GCM/NoPadding":
+        switch (wrappingAlgorithm.toUpperCase()) {
+            case "AES/GCM/NOPADDING":
                 return new AesGcm(key, provider, keyId);
             default:
                 throw new IllegalArgumentException("Right now only AES/GCM/NoPadding is supported");

src/test/java/com/amazonaws/encryptionsdk/AllTestsSuite.java

@@ -1,5 +1,6 @@
 package com.amazonaws.encryptionsdk;
 
+import com.amazonaws.encryptionsdk.jce.JceMasterKeyTest;
 import org.junit.runner.RunWith;
 import org.junit.runners.Suite;
 
@@ -52,7 +53,8 @@
         LocalCryptoMaterialsCacheThreadStormTest.class,
         UtilsTest.class,
         MultipleMasterKeyTest.class,
-        KMSProviderBuilderMockTests.class
+        KMSProviderBuilderMockTests.class,
+        JceMasterKeyTest.class
 })
 public class AllTestsSuite {
 }

src/test/java/com/amazonaws/encryptionsdk/internal/StaticMasterKey.java

@@ -55,7 +55,7 @@ public class StaticMasterKey extends MasterKey<StaticMasterKey> {
     /**
      * Encryption algorithm for the randomly generated data key
      */
-    private static final String DATA_KEY_ENCRHYPTION_ALGORITHM = "AES";
+    private static final String DATA_KEY_ENCRYPTION_ALGORITHM = "AES";
 
     /**
      * The ID of the master key
@@ -104,7 +104,7 @@ public StaticMasterKey(@Nonnull final String keyId) {
 
             masterKeyEncryptionCipher_ = Cipher.getInstance(MASTER_KEY_ENCRYPTION_ALGORITHM);
             masterKeyEncryptionCipher_.init(Cipher.ENCRYPT_MODE, pubKey);
-            
+
             masterKeyDecryptionCipher_ = Cipher.getInstance(MASTER_KEY_ENCRYPTION_ALGORITHM);
             masterKeyDecryptionCipher_.init(Cipher.DECRYPT_MODE, privKey);
 
@@ -135,7 +135,7 @@ public String getKeyId() {
     public DataKey<StaticMasterKey> generateDataKey(CryptoAlgorithm algorithm,
             Map<String, String> encryptionContext) {
         try {
-            this.keyGenerator_ = KeyGenerator.getInstance(DATA_KEY_ENCRHYPTION_ALGORITHM);
+            this.keyGenerator_ = KeyGenerator.getInstance(DATA_KEY_ENCRYPTION_ALGORITHM);
             this.keyGenerator_.init(algorithm.getDataKeyLength() * 8, SRAND);
             SecretKey key = new SecretKeySpec(keyGenerator_.generateKey().getEncoded(), algorithm.getDataKeyAlgo());
             byte[] encryptedKey = masterKeyEncryptionCipher_.doFinal(key.getEncoded());

src/test/java/com/amazonaws/encryptionsdk/jce/JceMasterKeyTest.java

@@ -0,0 +1,70 @@
+package com.amazonaws.encryptionsdk.jce;
+
+import org.junit.Test;
+
+import javax.crypto.SecretKey;
+import javax.crypto.spec.SecretKeySpec;
+import java.security.*;
+
+public class JceMasterKeyTest {
+
+    private static final SecretKey SECRET_KEY = new SecretKeySpec(new byte[1], "AES");
+    private static final PrivateKey PRIVATE_KEY;
+    private static final PublicKey PUBLIC_KEY;
+
+    static {
+        try {
+            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
+            KeyPair keyPair = keyPairGenerator.generateKeyPair();
+            PUBLIC_KEY = keyPair.getPublic();
+            PRIVATE_KEY = keyPair.getPrivate();
+        } catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private JceMasterKey jceGetInstance(final String algorithmName) {
+        return JceMasterKey.getInstance(SECRET_KEY, "mockProvider", "mockKey", algorithmName);
+    }
+
+    private JceMasterKey jceGetInstanceAsymmetric(final String algorithmName) {
+        return JceMasterKey.getInstance(PUBLIC_KEY, PRIVATE_KEY, "mockProvider",  "mockKey",
+                algorithmName);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testGetInstanceInvalidWrappingAlgorithm() {
+        jceGetInstance("blatently/unsupported/algorithm");
+    }
+
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void testGetInstanceAsymmetricInvalidWrappingAlgorithm() {
+        jceGetInstanceAsymmetric("rsa/ec/unsupportedAlgorithm");
+    }
+
+    /**
+     * Calls JceMasterKey.getInstance with differently cased wrappingAlgorithm names.
+     * Passes if no Exception is thrown.
+     * Relies on passing an invalid algorithm name to result in an Exception.
+     */
+    @Test
+    public void testGetInstanceAllLowercase() {
+        jceGetInstance("aes/gcm/nopadding");
+    }
+
+    @Test
+    public void testGetInstanceMixedCasing() {
+        jceGetInstance("AES/GCm/NOpadding");
+    }
+
+    @Test
+    public void testGetInstanceAsymmetricAllLowercase() {
+        jceGetInstanceAsymmetric("rsa/ecb/oaepwithsha-256andmgf1padding");
+    }
+
+    @Test
+    public void testGetInstanceAsymmetricMixedCasing() {
+        jceGetInstanceAsymmetric("RSA/ECB/OAepwithsha-256andmgf1padding");
+    }
+}