1 files changed, 157 insertions, 0 deletions
diff --git a/sshlib/src/main/java/com/trilead/ssh2/crypto/digest/MAC.java b/sshlib/src/main/java/com/trilead/ssh2/crypto/digest/MAC.java
new file mode 100644
index 0000000..561599c
--- /dev/null
+++ b/sshlib/src/main/java/com/trilead/ssh2/crypto/digest/MAC.java
@@ -0,0 +1,157 @@
+
+package com.trilead.ssh2.crypto.digest;
+
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.Mac;
+import javax.crypto.ShortBufferException;
+import javax.crypto.spec.SecretKeySpec;
+
+/**
+ * MAC.
+ * 
+ * @author Christian Plattner, plattner@trilead.com
+ * @version $Id: MAC.java,v 1.1 2007/10/15 12:49:57 cplattne Exp $
+ */
+public final class MAC
+{
+	/**
+	 * From http://tools.ietf.org/html/rfc4253
+	 */
+	private static final String HMAC_MD5 = "hmac-md5";
+
+	/**
+	 * From http://tools.ietf.org/html/rfc4253
+	 */
+	private static final String HMAC_MD5_96 = "hmac-md5-96";
+
+	/**
+	 * From http://tools.ietf.org/html/rfc4253
+	 */
+	private static final String HMAC_SHA1 = "hmac-sha1";
+
+	/**
+	 * From http://tools.ietf.org/html/rfc4253
+	 */
+	private static final String HMAC_SHA1_96 = "hmac-sha1-96";
+
+	/**
+	 * From http://tools.ietf.org/html/rfc6668
+	 */
+	private static final String HMAC_SHA2_256 = "hmac-sha2-256";
+
+	/**
+	 * From http://tools.ietf.org/html/rfc6668
+	 */
+	private static final String HMAC_SHA2_512 = "hmac-sha2-512";
+
+	Mac mac;
+	int outSize;
+	int macSize;
+	byte[] buffer;
+
+	/* Higher Priority First */
+	private static final String[] MAC_LIST = {
+		HMAC_SHA2_256, HMAC_SHA2_512,
+		HMAC_SHA1_96, HMAC_SHA1, HMAC_MD5_96, HMAC_MD5
+	};
+
+	public final static String[] getMacList()
+	{
+		return MAC_LIST;
+	}
+
+	public final static void checkMacList(String[] macs)
+	{
+		for (int i = 0; i < macs.length; i++)
+			getKeyLen(macs[i]);
+	}
+
+	public final static int getKeyLen(String type)
+	{
+		if (HMAC_SHA1.equals(type) || HMAC_SHA1_96.equals(type))
+			return 20;
+		if (HMAC_MD5.equals(type) || HMAC_MD5_96.equals(type))
+			return 16;
+		if (HMAC_SHA2_256.equals(type))
+			return 32;
+		if (HMAC_SHA2_512.equals(type))
+			return 64;
+		throw new IllegalArgumentException("Unkown algorithm " + type);
+	}
+
+	public MAC(String type, byte[] key)
+	{
+		try {
+			if (HMAC_SHA1.equals(type) || HMAC_SHA1_96.equals(type))
+			{
+				mac = Mac.getInstance("HmacSHA1");
+			}
+			else if (HMAC_MD5.equals(type) || HMAC_MD5_96.equals(type))
+			{
+				mac = Mac.getInstance("HmacMD5");
+			}
+			else if (HMAC_SHA2_256.equals(type))
+			{
+				mac = Mac.getInstance("HmacSHA256");
+			}
+			else if (HMAC_SHA2_512.equals(type))
+			{
+				mac = Mac.getInstance("HmacSHA512");
+			}
+			else
+				throw new IllegalArgumentException("Unkown algorithm " + type);
+		} catch (NoSuchAlgorithmException e) {
+			throw new IllegalArgumentException("Unknown algorithm " + type, e);
+		}
+
+		macSize = mac.getMacLength();
+		if (type.endsWith("-96")) {
+			outSize = 12;
+			buffer = new byte[macSize];
+		} else {
+			outSize = macSize;
+			buffer = null;
+		}
+
+		try {
+			mac.init(new SecretKeySpec(key, type));
+		} catch (InvalidKeyException e) {
+			throw new IllegalArgumentException(e);
+		}
+	}
+
+	public final void initMac(int seq)
+	{
+		mac.reset();
+		mac.update((byte) (seq >> 24));
+		mac.update((byte) (seq >> 16));
+		mac.update((byte) (seq >> 8));
+		mac.update((byte) (seq));
+	}
+
+	public final void update(byte[] packetdata, int off, int len)
+	{
+		mac.update(packetdata, off, len);
+	}
+
+	public final void getMac(byte[] out, int off)
+	{
+		try {
+			if (buffer != null) {
+				mac.doFinal(buffer, 0);
+				System.arraycopy(buffer, 0, out, off, out.length - off);
+			} else {
+				mac.doFinal(out, off);
+			}
+		} catch (ShortBufferException e) {
+			throw new IllegalStateException(e);
+		}
+	}
+
+	public final int size()
+	{
+		return outSize;
+	}
+}