X-Git-Url: https://git.argeo.org/?a=blobdiff_plain;f=org.argeo.util%2Fsrc%2Forg%2Fargeo%2Futil%2FDigestUtils.java;fp=org.argeo.util%2Fsrc%2Forg%2Fargeo%2Futil%2FDigestUtils.java;h=52cbc5d21a3b801885a88555c1ad9d88463938b2;hb=77a5498dd5d10d2442127022efd6501a7dbddbae;hp=0000000000000000000000000000000000000000;hpb=61780b581925666edd4bd7743a00dca7170f1d35;p=lgpl%2Fargeo-commons.git

diff --git a/org.argeo.util/src/org/argeo/util/DigestUtils.java b/org.argeo.util/src/org/argeo/util/DigestUtils.java
new file mode 100644
index 000000000..52cbc5d21
--- /dev/null
+++ b/org.argeo.util/src/org/argeo/util/DigestUtils.java
@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2007-2012 Argeo GmbH
+ *
+ * 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.
+ */
+package org.argeo.util;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+/** Utilities around cryptographic digests */
+public class DigestUtils {
+	private static Boolean debug = true;
+	// TODO: make it writable
+	private final static Integer byteBufferCapacity = 100 * 1024;// 100 KB
+
+	public static String digest(String algorithm, byte[] bytes) {
+		try {
+			MessageDigest digest = MessageDigest.getInstance(algorithm);
+			digest.update(bytes);
+			byte[] checksum = digest.digest();
+			String res = encodeHexString(checksum);
+			return res;
+		} catch (Exception e) {
+			throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
+		}
+	}
+
+	public static String digest(String algorithm, InputStream in) {
+		try {
+			MessageDigest digest = MessageDigest.getInstance(algorithm);
+			// ReadableByteChannel channel = Channels.newChannel(in);
+			// ByteBuffer bb = ByteBuffer.allocateDirect(byteBufferCapacity);
+			// while (channel.read(bb) > 0)
+			// digest.update(bb);
+			byte[] buffer = new byte[byteBufferCapacity];
+			int read = 0;
+			while ((read = in.read(buffer)) > 0) {
+				digest.update(buffer, 0, read);
+			}
+
+			byte[] checksum = digest.digest();
+			String res = encodeHexString(checksum);
+			return res;
+		} catch (Exception e) {
+			throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
+		} finally {
+			StreamUtils.closeQuietly(in);
+		}
+	}
+
+	public static String digest(String algorithm, File file) {
+		FileInputStream fis = null;
+		FileChannel fc = null;
+		try {
+			fis = new FileInputStream(file);
+			fc = fis.getChannel();
+
+			// Get the file's size and then map it into memory
+			int sz = (int) fc.size();
+			ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, sz);
+			return digest(algorithm, bb);
+		} catch (IOException e) {
+			throw new UtilsException("Cannot digest " + file + " with algorithm " + algorithm, e);
+		} finally {
+			StreamUtils.closeQuietly(fis);
+			if (fc.isOpen())
+				try {
+					fc.close();
+				} catch (IOException e) {
+					// silent
+				}
+		}
+	}
+
+	protected static String digest(String algorithm, ByteBuffer bb) {
+		long begin = System.currentTimeMillis();
+		try {
+			MessageDigest digest = MessageDigest.getInstance(algorithm);
+			digest.update(bb);
+			byte[] checksum = digest.digest();
+			String res = encodeHexString(checksum);
+			long end = System.currentTimeMillis();
+			if (debug)
+				System.out.println((end - begin) + " ms / " + ((end - begin) / 1000) + " s");
+			return res;
+		} catch (NoSuchAlgorithmException e) {
+			throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
+		}
+	}
+
+	public static void main(String[] args) {
+		File file;
+		if (args.length > 0)
+			file = new File(args[0]);
+		else {
+			System.err.println("Usage: <file> [<algorithm>]" + " (see http://java.sun.com/j2se/1.5.0/"
+					+ "docs/guide/security/CryptoSpec.html#AppA)");
+			return;
+		}
+
+		if (args.length > 1) {
+			String algorithm = args[1];
+			System.out.println(digest(algorithm, file));
+		} else {
+			String algorithm = "MD5";
+			System.out.println(algorithm + ": " + digest(algorithm, file));
+			algorithm = "SHA";
+			System.out.println(algorithm + ": " + digest(algorithm, file));
+			algorithm = "SHA-256";
+			System.out.println(algorithm + ": " + digest(algorithm, file));
+			algorithm = "SHA-512";
+			System.out.println(algorithm + ": " + digest(algorithm, file));
+		}
+	}
+
+	final private static char[] hexArray = "0123456789ABCDEF".toCharArray();
+
+	/**
+	 * From
+	 * http://stackoverflow.com/questions/9655181/how-to-convert-a-byte-array-to
+	 * -a-hex-string-in-java
+	 */
+	private static String encodeHexString(byte[] bytes) {
+		char[] hexChars = new char[bytes.length * 2];
+		for (int j = 0; j < bytes.length; j++) {
+			int v = bytes[j] & 0xFF;
+			hexChars[j * 2] = hexArray[v >>> 4];
+			hexChars[j * 2 + 1] = hexArray[v & 0x0F];
+		}
+		return new String(hexChars);
+	}
+
+}