Enhancement to use the common CryptoUtils

Change-Id: I06718526382b424eab991f39a7dac1b5cf4f1b74
Issue-ID: POLICY-1422
Signed-off-by: pa834y <pa834y@att.com>

4 files changed, 166 insertions, 384 deletions

diff --git a/PolicyEngineUtils/src/main/java/org/onap/policy/utils/CryptoUtils.java b/PolicyEngineUtils/src/main/java/org/onap/policy/utils/CryptoUtils.java
deleted file mode 100644
index 15a93bdab..000000000
--- a/PolicyEngineUtils/src/main/java/org/onap/policy/utils/CryptoUtils.java
+++ /dev/null
@@ -1,256 +0,0 @@
-/*-
- * ============LICENSE_START=======================================================
- * PolicyEngineUtils
- * ================================================================================
- * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
- * ================================================================================
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * 
- *      http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- * ============LICENSE_END=========================================================
- */
-package org.onap.policy.utils;
-
-import java.nio.charset.StandardCharsets;
-import java.security.AlgorithmParameters;
-import java.security.InvalidAlgorithmParameterException;
-import java.security.InvalidKeyException;
-import java.security.NoSuchAlgorithmException;
-import java.security.Key;
-import java.util.Base64;
-
-import javax.crypto.BadPaddingException;
-import javax.crypto.Cipher;
-import javax.crypto.IllegalBlockSizeException;
-import javax.crypto.NoSuchPaddingException;
-import javax.crypto.spec.SecretKeySpec;
-import javax.xml.bind.DatatypeConverter;
-
-import org.onap.policy.common.logging.flexlogger.FlexLogger;
-import org.onap.policy.common.logging.flexlogger.Logger;
-
-public class CryptoUtils {
-	private static final Logger LOGGER = FlexLogger.getLogger(CryptoUtils.class);
-	private static final String CIPHER_TYPE = "AES/CBC/PKCS5Padding";
-	private static Key mKey = null;
-	private static AlgorithmParameters mAlgParm = null;
-
-	static {
-		//the hadcoded key is to be removed in a future iteration
-		try {
-			String kval = "bmpybWJrbGN4dG9wbGF3Zg==";
-			String algp = "BBBpbml0VmVjVGhpc0lzVGhl";
-
-			byte[] kvalb = DatatypeConverter.parseBase64Binary(kval);
-			byte[] algb = DatatypeConverter.parseBase64Binary(algp);
-
-			mKey = new SecretKeySpec(kvalb, "AES");
-
-			mAlgParm = AlgorithmParameters.getInstance("AES");
-			mAlgParm.init(algb, "ASN.1");
-
-		} catch (Exception ex) {
-			throw new ExceptionInInitializerError(ex);
-		}
-	}
-
-	private CryptoUtils() {
-		// Private Constructor
-	}
-
-	/**
-	 * Decrypt txt.
-	 *
-	 * @param encryptedTxt
-	 *            text to be decrypted, Base 64 UrlEncoded
-	 * @return the byte[]
-	 * @throws NoSuchAlgorithmException
-	 *             the no such algorithm exception
-	 * @throws NoSuchPaddingException
-	 *             the no such padding exception
-	 * @throws InvalidAlgorithmParameterException
-	 *             the invalid algorithm parameter exception
-	 * @throws InvalidKeyException
-	 *             the invalid key exception
-	 * @throws IllegalBlockSizeException
-	 *             the illegal block size exception
-	 * @throws BadPaddingException
-	 *             the bad padding exception
-	 */
-	public static byte[] decryptTxt(String encryptedTxt)
-			throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException,
-			InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
-		Cipher cipher = Cipher.getInstance(CIPHER_TYPE);
-		cipher.init(Cipher.DECRYPT_MODE, mKey, mAlgParm);
-
-		return cipher.doFinal(Base64.getUrlDecoder().decode(encryptedTxt.getBytes(StandardCharsets.UTF_8)));
-	}
-
-	/**
-	 * Decrypt txt.
-	 *
-	 * @param encryptedTxt
-	 *            text to be decrypted, Base 64 UrlEncoded
-	 * @param mKey
-	 *            the key as Base 64
-	 * @return the byte[]
-	 * @throws NoSuchAlgorithmException
-	 *             the no such algorithm exception
-	 * @throws NoSuchPaddingException
-	 *             the no such padding exception
-	 * @throws InvalidAlgorithmParameterException
-	 *             the invalid algorithm parameter exception
-	 * @throws InvalidKeyException
-	 *             the invalid key exception
-	 * @throws IllegalBlockSizeException
-	 *             the illegal block size exception
-	 * @throws BadPaddingException
-	 *             the bad padding exception
-	 */
-	public static byte[] decryptTxt(String encryptedTxt, String base64BinaryKey)
-			throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException,
-			InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
-
-		byte[] keyValueByte = DatatypeConverter.parseBase64Binary(base64BinaryKey);
-		Key paramKey = new SecretKeySpec(keyValueByte, "AES");
-		Cipher cipher = Cipher.getInstance(CIPHER_TYPE);
-		cipher.init(Cipher.DECRYPT_MODE, paramKey, mAlgParm);
-
-		return cipher.doFinal(Base64.getUrlDecoder().decode(encryptedTxt.getBytes(StandardCharsets.UTF_8)));
-	}
-
-	/**
-	 * Decrypt txt, no exceptions thrown.
-	 *
-	 * @param encryptedTxt
-	 *            text to be decrypted, Base 64 UrlEncoded
-	 * @return the decrypted text, or the original text if it could not be
-	 *         decrypted
-	 */
-	public static byte[] decryptTxtNoEx(String encryptedTxt) {
-
-		try {
-			if (encryptedTxt == null || encryptedTxt.isEmpty()) {
-				LOGGER.info("decryptTxtNoEx: Input param encryptedTxt is empty");
-				return new byte[0];
-			}
-			return decryptTxt(encryptedTxt);
-		} catch (Exception e) {
-			try {
-				LOGGER.info("decryptTxtNoEx: Exception while decrypting : " + e);
-				return (encryptedTxt != null) ? encryptedTxt.getBytes(StandardCharsets.UTF_8) : new byte[0];
-			} catch (Exception e1) {
-				LOGGER.warn("decryptTxtNoEx: Exception on sending default : " + e1);
-				return new byte[0];
-			}
-		}
-	}
-	
-	/**
-	 * Decrypt txt, no exceptions thrown.
-	 *
-	 * @param encryptedTxt
-	 *            text to be decrypted, Base 64 UrlEncoded
-	 * @return the decrypted text, or the original text if it could not be
-	 *         decrypted
-	 */
-	public static String decryptTxtNoExStr(String encryptedTxt) {
-			return new String(decryptTxtNoEx(encryptedTxt), StandardCharsets.UTF_8);
-	}
-
-	/**
-	 * Encrypt txt.
-	 *
-	 * @param plainTxt
-	 *            the plain txt
-	 * @return the encrypted string
-	 * @throws NoSuchPaddingException
-	 *             the no such padding exception
-	 * @throws InvalidAlgorithmParameterException
-	 *             the invalid algorithm parameter exception
-	 * @throws NoSuchAlgorithmException
-	 *             the no such algorithm exception
-	 * @throws InvalidKeyException
-	 *             the invalid key exception
-	 * @throws IllegalBlockSizeException
-	 *             the illegal block size exception
-	 * @throws BadPaddingException
-	 *             the bad padding exception
-	 */
-	public static String encryptTxt(byte[] plainTxt)
-			throws NoSuchPaddingException, InvalidAlgorithmParameterException,
-			NoSuchAlgorithmException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
-
-		Cipher cipher = Cipher.getInstance(CIPHER_TYPE);
-		cipher.init(Cipher.ENCRYPT_MODE, mKey, mAlgParm);
-
-		byte[] encryption = cipher.doFinal(plainTxt);
-		return new String(Base64.getUrlEncoder().encode(encryption), StandardCharsets.UTF_8);
-	}
-
-	/**
-	 * Encrypt txt.
-	 *
-	 * @param plainTxt
-	 *            the plain txt to be encrypted
-	 * @param base64BinaryKey
-	 *            the key as lexical representation of Base64 Binary
-	 * @return the encrypted string
-	 * @throws NoSuchPaddingException
-	 *             the no such padding exception
-	 * @throws InvalidAlgorithmParameterException
-	 *             the invalid algorithm parameter exception
-	 * @throws NoSuchAlgorithmException
-	 *             the no such algorithm exception
-	 * @throws InvalidKeyException
-	 *             the invalid key exception
-	 * @throws IllegalBlockSizeException
-	 *             the illegal block size exception
-	 * @throws BadPaddingException
-	 *             the bad padding exception
-	 */
-	public static String encryptTxt(byte[] plainTxt, String base64BinaryKey)
-			throws NoSuchPaddingException, InvalidAlgorithmParameterException,
-			NoSuchAlgorithmException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
-
-		byte[] keyValueByte = DatatypeConverter.parseBase64Binary(base64BinaryKey);
-		Key paramKey = new SecretKeySpec(keyValueByte, "AES");
-		Cipher cipher = Cipher.getInstance(CIPHER_TYPE);
-		cipher.init(Cipher.ENCRYPT_MODE, paramKey, mAlgParm);
-
-		byte[] encryption = cipher.doFinal(plainTxt);
-		return new String(Base64.getMimeEncoder().encode(encryption), StandardCharsets.UTF_8);
-	}
-
-	/**
-	 * Encrypt txt, no exceptions thrown
-	 *
-	 * @param plainTxt
-	 *            the plain txt to be encrypted
-	 * @return the encrypted String , or the original text if it could not be
-	 *         encrypted
-	 */
-	public static String encryptTxtNoEx(byte[] plainTxt) {
-
-		if (plainTxt == null || plainTxt.length == 0) {
-			LOGGER.error("encryptTxtNoEx: Input param plainTxt is not valid");
-			return "";
-		}
-
-		try {
-			return encryptTxt(plainTxt);
-		} catch (Exception e) {
-			LOGGER.error("encryptTxtNoEx: Exception while decryption : " + e);
-			return new String(plainTxt, StandardCharsets.UTF_8);
-		}
-	}
-
-}
\ No newline at end of file
diff --git a/PolicyEngineUtils/src/main/java/org/onap/policy/utils/PeCryptoUtils.java b/PolicyEngineUtils/src/main/java/org/onap/policy/utils/PeCryptoUtils.java
new file mode 100644
index 000000000..9863f03ad
--- /dev/null
+++ b/PolicyEngineUtils/src/main/java/org/onap/policy/utils/PeCryptoUtils.java
@@ -0,0 +1,102 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP Policy Engine
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.utils;
+
+import java.security.GeneralSecurityException;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import org.apache.commons.lang3.StringUtils;
+import org.onap.policy.common.logging.flexlogger.FlexLogger;
+import org.onap.policy.common.logging.flexlogger.Logger;
+import org.onap.policy.common.utils.security.CryptoUtils;
+
+public class PeCryptoUtils {
+
+    private static Logger logger = FlexLogger.getLogger(PeCryptoUtils.class);
+    private static final String PROP_AES_KEY = "org.onap.policy.encryption.aes.key";
+    private static CryptoUtils cryptoUtils = null;
+    private static String secretKey = System.getenv("AES_ENCRYPTION_KEY");
+    private static final Map<String, String> decryptCache = new ConcurrentHashMap<>();
+    private static final Map<String, String> encryptCache = new ConcurrentHashMap<>();
+
+
+    private PeCryptoUtils() {}
+
+    /**
+     * Inits the aes key.
+     *
+     * @param theSecretKey the the secret key
+     */
+    public static synchronized void initAesKey(String theSecretKey) {
+        String secKey = theSecretKey;
+        if (cryptoUtils == null) {
+            if (StringUtils.isBlank(secKey)) {
+                secKey = System.getProperty(PROP_AES_KEY);
+            }
+            if (StringUtils.isBlank(secKey)) {
+                secKey = secretKey;
+            }
+            cryptoUtils = new CryptoUtils(secKey);
+        }
+    }
+
+    /**
+     * Encrypt a value based on the Policy Encryption Key.
+     *
+     * @param value The plain text string
+     * @return The encrypted String
+     */
+    public static String encrypt(String value) {
+
+        if (cryptoUtils == null || StringUtils.isBlank(value)) {
+            return value;
+        }
+
+        return encryptCache.computeIfAbsent(value, k -> {
+            try {
+                return cryptoUtils.encrypt(k);
+            } catch (GeneralSecurityException e) {
+                logger.error("Could not decrypt value - exception: ", e);
+                return value;
+            }
+        });
+    }
+
+    /**
+     * Decrypt a value based on the Policy Encryption Key if string begin with 'enc:'.
+     *
+     * @param value The encrypted string that must be decrypted using the Policy Encryption Key
+     * @return The String decrypted if string begin with 'enc:'
+     */
+    public static String decrypt(String value) {
+        if (cryptoUtils == null || StringUtils.isBlank(value)) {
+            return value;
+        }
+        return decryptCache.computeIfAbsent(value, k -> {
+            try {
+                return cryptoUtils.decrypt(k);
+            } catch (GeneralSecurityException e) {
+                logger.error("Could not decrypt value - exception: ", e);
+                return value;
+            }
+        });
+    }
+}
diff --git a/PolicyEngineUtils/src/test/java/org/onap/policy/utils/PeCryptoUtilsTest.java b/PolicyEngineUtils/src/test/java/org/onap/policy/utils/PeCryptoUtilsTest.java
new file mode 100644
index 000000000..3765ff2e3
--- /dev/null
+++ b/PolicyEngineUtils/src/test/java/org/onap/policy/utils/PeCryptoUtilsTest.java
@@ -0,0 +1,64 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP-REST
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.utils;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import java.security.GeneralSecurityException;
+import org.junit.Before;
+import org.junit.Test;
+import org.powermock.reflect.Whitebox;
+
+
+public class PeCryptoUtilsTest {
+    private final String pass = "policy_user";
+    private final String secretKey = "bmpybWJrbGN4dG9wbGF3Zg==";
+    private final String encryptedPass = "enc:5ID9PoqWIzBaut+KQcAFBtci9CKDRcCNRHRjdBnXM5U=";
+    private static final String PROP_AES_KEY = "org.onap.policy.encryption.aes.key";
+
+    @Before
+    public void reset() {
+        Whitebox.setInternalState( PeCryptoUtils.class, "cryptoUtils", (PeCryptoUtils)null);
+
+    }
+
+    @Test
+    public void testEncrypt() throws GeneralSecurityException {
+        assertEquals(pass, PeCryptoUtils.encrypt(pass));
+        PeCryptoUtils.initAesKey(secretKey);
+        System.out.println("original value : " + pass + "  encrypted value: " + PeCryptoUtils.encrypt(pass));
+        assertNotNull(PeCryptoUtils.encrypt(pass));
+    }
+
+    @Test
+    public void testDecrypt() throws Exception {
+        assertEquals(pass, PeCryptoUtils.decrypt(pass));
+        System.setProperty(PROP_AES_KEY, secretKey);
+        PeCryptoUtils.initAesKey(null);
+        System.clearProperty(PROP_AES_KEY);
+        assertEquals(pass, PeCryptoUtils.decrypt(encryptedPass));
+        Whitebox.setInternalState( PeCryptoUtils.class, "cryptoUtils", (PeCryptoUtils)null);
+        Whitebox.setInternalState( PeCryptoUtils.class, "secretKey", secretKey);
+        PeCryptoUtils.initAesKey(" ");
+        assertEquals(pass, PeCryptoUtils.decrypt(pass));
+    }
+
+}
diff --git a/PolicyEngineUtils/src/test/java/org/onap/policy/utils/test/CryptoUtilsTest.java b/PolicyEngineUtils/src/test/java/org/onap/policy/utils/test/CryptoUtilsTest.java
deleted file mode 100644
index e2ca78a06..000000000
--- a/PolicyEngineUtils/src/test/java/org/onap/policy/utils/test/CryptoUtilsTest.java
+++ /dev/null
@@ -1,128 +0,0 @@
-/*-
- * ============LICENSE_START=======================================================
- * PolicyEngineUtils
- * ================================================================================
- * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
- * ================================================================================
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * 
- *      http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- * ============LICENSE_END=========================================================
- */
-package org.onap.policy.utils.test;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertArrayEquals;
-
-import java.nio.charset.StandardCharsets;
-import java.security.InvalidAlgorithmParameterException;
-import java.security.InvalidKeyException;
-import java.security.NoSuchAlgorithmException;
-
-import javax.crypto.BadPaddingException;
-import javax.crypto.IllegalBlockSizeException;
-import javax.crypto.NoSuchPaddingException;
-
-import org.junit.Test;
-import org.onap.policy.utils.CryptoUtils;
-
-public class CryptoUtilsTest {
-
-	@Test
-	public final void testDecryptTxt() throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException,
-			InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException
-			 {
-		String decryptedTxt = new String(CryptoUtils.decryptTxt("g0uHKXCLyzJ6wSbpphNGsA=="), StandardCharsets.UTF_8);
-		assertEquals("mypass", decryptedTxt);
-	}
-
-	@Test
-	public final void testDecryptTxtWithKey() throws InvalidKeyException, NoSuchAlgorithmException,
-			NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException
-			 {
-		String decryptedTxt = new String(CryptoUtils.decryptTxt("g0uHKXCLyzJ6wSbpphNGsA==", "bmpybWJrbGN4dG9wbGF3Zg=="),
-				StandardCharsets.UTF_8);
-		assertEquals("mypass", decryptedTxt);
-	}
-
-	@Test
-	public final void testDecryptTxtNoEx() {
-		String decryptedTxt = new String(CryptoUtils.decryptTxtNoEx("g0uHKXCLyzJ6wSbpphNGsA=="),
-				StandardCharsets.UTF_8);
-		assertEquals("mypass", decryptedTxt);
-
-	}
-
-	@Test
-	public final void testDecryptTxtNoExStr() {
-		assertEquals("mypass", CryptoUtils.decryptTxtNoExStr("g0uHKXCLyzJ6wSbpphNGsA=="));
-	}
-	@Test
-	public final void testDecryptTxtNoExInvalidInput() {
-		assertArrayEquals(new byte[0], CryptoUtils.decryptTxtNoEx(null));
-		assertArrayEquals(new byte[0], CryptoUtils.decryptTxtNoEx(""));
-		// ensure backward compatibility
-		assertEquals("bogus", new String(CryptoUtils.decryptTxtNoEx("bogus"), StandardCharsets.UTF_8));
-		assertEquals("admin123", CryptoUtils.decryptTxtNoExStr("admin123"));
-		assertEquals("password", CryptoUtils.decryptTxtNoExStr("password"));
-	}
-
-	@Test(expected = IllegalArgumentException.class)
-	public final void testDecryptTxtInvalidInput() throws InvalidKeyException, NoSuchAlgorithmException,
-			NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException
-			 {
-		CryptoUtils.decryptTxt("bogus");
-	}
-
-	@Test
-	public final void testEncryptTxt() throws InvalidKeyException, NoSuchPaddingException,
-			InvalidAlgorithmParameterException, NoSuchAlgorithmException, IllegalBlockSizeException,
-			BadPaddingException {
-		String txtStr = "mypass";
-		byte[] txt = txtStr.getBytes(StandardCharsets.UTF_8);
-		assertEquals("g0uHKXCLyzJ6wSbpphNGsA==", CryptoUtils.encryptTxt(txt));
-	}
-
-	@Test
-	public final void testEncryptTxtWithKey() throws InvalidKeyException,
-			NoSuchPaddingException, InvalidAlgorithmParameterException, NoSuchAlgorithmException,
-			IllegalBlockSizeException, BadPaddingException {
-		String txtStr = "mypass";
-		byte[] txt = txtStr.getBytes(StandardCharsets.UTF_8);
-		assertEquals("g0uHKXCLyzJ6wSbpphNGsA==", CryptoUtils.encryptTxt(txt, "bmpybWJrbGN4dG9wbGF3Zg=="));
-	}
-
-	@Test
-	public final void testEncryptTxtNoEx() {
-		String txtStr = "mypass";
-		byte[] txt = txtStr.getBytes(StandardCharsets.UTF_8);
-		assertEquals("g0uHKXCLyzJ6wSbpphNGsA==", CryptoUtils.encryptTxtNoEx(txt));
-	}
-
-	@Test
-	public final void testEncryptTxtNoExInvalidInput() {
-		String txtStr = "";
-		byte[] txt = txtStr.getBytes(StandardCharsets.UTF_8);
-		assertEquals("", CryptoUtils.encryptTxtNoEx(txt));
-		assertEquals("", CryptoUtils.encryptTxtNoEx(null));
-	}
-
-	@Test(expected = InvalidKeyException.class)
-	public final void testEncryptTxtWithKeyInvalid() throws InvalidKeyException,
-			NoSuchPaddingException, InvalidAlgorithmParameterException, NoSuchAlgorithmException,
-			IllegalBlockSizeException, BadPaddingException {
-		String txtStr = "mypass";
-		byte[] txt = txtStr.getBytes(StandardCharsets.UTF_8);
-		CryptoUtils.encryptTxt(txt, "mykey");
-	}
-
-
-}
\ No newline at end of file