1 files changed, 109 insertions, 0 deletions
diff --git a/source/util/Hasher.java b/source/util/Hasher.java
new file mode 100644
index 0000000..0458e94
--- /dev/null
+++ b/source/util/Hasher.java
@@ -0,0 +1,109 @@
+/*
+ * Created on Mar 1, 2004
+ * Algorithm:
+ * Copyright (c) 2004 David Hammerton
+ *
+ * port to java:
+ * Copyright (c) 2004 Joseph Barnett
+ */
+package itunes.util;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+/**
+ * @author jbarnett
+ */
+public class Hasher {	
+		//taken from calculations in libopendaap
+	//private static String staticHash = "98814088228B81E0AB021433618EC27B";
+	private static String calcHash = "";
+	private static boolean staticCalculated = false;
+	
+	private static final String hexchars = "0123456789ABCDEF";
+	private static final String appleCopyright = "Copyright 2003 Apple Computer, Inc.";
+	private static MessageDigest md;
+	
+	private static final int HASH_SIZE = 32;
+	
+	static {
+		try {
+			md = MessageDigest.getInstance("md5");
+		} catch (NoSuchAlgorithmException e) {
+			e.printStackTrace();
+		}
+	}
+	
+	private static String DigestToString(byte[] digest)
+	{
+		String string="";
+		int i;
+		for (i = 0; i < digest.length; i++)
+		{
+			byte tmp = digest[i];
+			string += hexchars.charAt((tmp >> 4) & 0x0f);
+			string += hexchars.charAt(tmp & 0x0f);
+		}
+		return string;
+	}	
+	
+	private static synchronized void calculateStaticHash() {
+		if (staticCalculated)
+			return;
+		for (int i = 0; i < 256; i++) {
+			if ((i & 0x80) != 0)
+				md.update("Accept-Language".getBytes());
+			else
+				md.update("user-agent".getBytes());
+
+			if ((i & 0x40) != 0)
+				md.update("max-age".getBytes());
+			else
+				md.update("Authorization".getBytes());
+
+			if ((i & 0x20) != 0)
+				md.update("Client-DAAP-Version".getBytes());
+			else
+				md.update("Accept-Encoding".getBytes());
+
+			if ((i & 0x10) != 0)
+				md.update("daap.protocolversion".getBytes());
+			else
+				md.update("daap.songartist".getBytes());
+
+			if ((i & 0x08) != 0)
+				md.update("daap.songcomposer".getBytes());
+			else
+				md.update("daap.songdatemodified".getBytes());
+
+			if ((i & 0x04) != 0)
+				md.update("daap.songdiscnumber".getBytes());
+			else
+				md.update("daap.songdisabled".getBytes());
+
+			if ((i & 0x02) != 0)
+				md.update("playlist-item-spec".getBytes());
+			else
+				md.update("revision-number".getBytes());
+
+			if ((i & 0x01) != 0)
+				md.update("session-id".getBytes());
+			else
+				md.update("content-codes".getBytes());	
+			
+			String newHash =DigestToString(md.digest()); 
+			calcHash += newHash;
+		}
+		staticCalculated = true;
+	}
+	
+	public static String GenerateHash(String url, int accessIndex) {
+		int start = HASH_SIZE * accessIndex;
+		int end = start + HASH_SIZE;
+		calculateStaticHash();	
+		md.update(url.getBytes());
+		md.update(appleCopyright.getBytes());
+		md.update(calcHash.substring(start, end).getBytes());
+		return DigestToString(md.digest());
+	}
+}