1 files changed, 61 insertions, 0 deletions
diff --git a/bundles/org.eclipse.equinox.p2.repository/src/org/eclipse/equinox/internal/p2/repository/helpers/ChecksumProducer.java b/bundles/org.eclipse.equinox.p2.repository/src/org/eclipse/equinox/internal/p2/repository/helpers/ChecksumProducer.java
new file mode 100644
index 000000000..a9c1c5a9f
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.repository/src/org/eclipse/equinox/internal/p2/repository/helpers/ChecksumProducer.java
@@ -0,0 +1,61 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2016 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *     Mykola Nikishov - extract MD5 checksum calculation
+ *******************************************************************************/
+
+package org.eclipse.equinox.internal.p2.repository.helpers;
+
+import java.io.*;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+public class ChecksumProducer {
+
+	public static String computeMD5(File file) {
+		if (file == null || file.isDirectory() || !file.exists())
+			return null;
+		MessageDigest md5Checker;
+		try {
+			md5Checker = MessageDigest.getInstance("MD5"); //$NON-NLS-1$
+		} catch (NoSuchAlgorithmException e) {
+			return null;
+		}
+		InputStream fis = null;
+		try {
+			fis = new BufferedInputStream(new FileInputStream(file));
+			int read = -1;
+			final int bufferSize = 4 * 1024;
+			byte[] buffer = new byte[bufferSize];
+			while ((read = fis.read(buffer, 0, bufferSize)) != -1) {
+				md5Checker.update(buffer, 0, read);
+			}
+			byte[] digest = md5Checker.digest();
+			StringBuffer buf = new StringBuffer();
+			for (int i = 0; i < digest.length; i++) {
+				if ((digest[i] & 0xFF) < 0x10)
+					buf.append('0');
+				buf.append(Integer.toHexString(digest[i] & 0xFF));
+			}
+			return buf.toString();
+		} catch (FileNotFoundException e) {
+			return null;
+		} catch (IOException e) {
+			return null;
+		} finally {
+			if (fis != null)
+				try {
+					fis.close();
+				} catch (IOException e) {
+					// ignore
+				}
+		}
+	}
+
+}