Merge pull request #31 from Glusk2/hmac

#30 Added a HMAC implementation.

wse-common/src/main/java/com/github/glusk2/wse/common/crypto/util/hashing/DigestArgument.java

@@ -1,5 +1,7 @@
 package com.github.glusk2.wse.common.crypto.util.hashing;
 
+import javax.xml.bind.DatatypeConverter;
+
 public interface DigestArgument {
 
     byte[] bytes();
@@ -8,6 +10,10 @@ final class BYTES implements DigestArgument {
 
         private final byte[] bytes;
 
+        public BYTES(String hex) {
+            this(DatatypeConverter.parseHexBinary(hex));
+        }
+
         public BYTES(byte... bytes) {
             this.bytes = bytes;
         }

wse-common/src/main/java/com/github/glusk2/wse/common/crypto/util/hashing/Hmac.java

@@ -0,0 +1,65 @@
+package com.github.glusk2.wse.common.crypto.util.hashing;
+
+public final class Hmac implements DigestArgument {
+    private static final byte OPAD_BYTE = 0x5c;
+    private static final byte IPAD_BYTE = 0x36;
+    public static final int DEFAULT_BLOCK_SIZE = 64;
+
+    private final IntermediateDigest hmac;
+
+    public Hmac(
+        ImmutableMessageDigest imd,
+        DigestArgument key,
+        DigestArgument message
+    ) {
+        this(imd, key, DEFAULT_BLOCK_SIZE, message);
+    }
+
+    public Hmac(
+        ImmutableMessageDigest imd,
+        DigestArgument key,
+        int blockSize,
+        DigestArgument message
+    ) {
+        this(
+            imd,
+            new XoredArguments(
+                new HmacKey(imd, key, blockSize),
+                new ValueExpansion(OPAD_BYTE, blockSize)
+            ),
+            new XoredArguments(
+                new HmacKey(imd, key, blockSize),
+                new ValueExpansion(IPAD_BYTE, blockSize)
+            ),
+            message
+        );
+    }
+
+    public Hmac(
+        ImmutableMessageDigest imd,
+        DigestArgument opad,
+        DigestArgument ipad,
+        DigestArgument message
+    ) {
+        this(
+            new IntermediateDigest(
+                imd,
+                opad,
+                new IntermediateDigest(
+                    imd,
+                    ipad,
+                    message
+                )
+            )
+        );
+    }
+
+    public Hmac(IntermediateDigest hmac) {
+        this.hmac = hmac;
+    }
+
+    @Override
+    public byte[] bytes() {
+        return hmac.bytes();
+    }
+}

wse-common/src/main/java/com/github/glusk2/wse/common/crypto/util/hashing/HmacKey.java

@@ -0,0 +1,29 @@
+package com.github.glusk2.wse.common.crypto.util.hashing;
+
+import java.util.Arrays;
+
+public final class HmacKey implements DigestArgument {
+
+    private final ImmutableMessageDigest imd;
+    private final DigestArgument key;
+    private final int blockSize;
+
+    public HmacKey(
+        ImmutableMessageDigest imd,
+        DigestArgument key,
+        int blockSize
+    ) {
+        this.imd = imd;
+        this.key = key;
+        this.blockSize = blockSize;
+    }
+
+    @Override
+    public byte[] bytes() {
+        byte[] keyBytes = key.bytes();
+        if (keyBytes.length <= blockSize) {
+            return Arrays.copyOf(keyBytes, blockSize);
+        }
+        return imd.update(key).digest();
+    }
+}

wse-common/src/main/java/com/github/glusk2/wse/common/crypto/util/hashing/ValueExpansion.java

@@ -0,0 +1,21 @@
+package com.github.glusk2.wse.common.crypto.util.hashing;
+
+import java.util.Arrays;
+
+public final class ValueExpansion implements DigestArgument {
+
+    private final byte value;
+    private final int length;
+
+    public ValueExpansion(byte value, int length) {
+        this.value = value;
+        this.length = length;
+    }
+
+    @Override
+    public byte[] bytes() {
+        byte[] result = new byte[length];
+        Arrays.fill(result, value);
+        return result;
+    }
+}

wse-common/src/test/java/com/github/glusk2/wse/common/crypto/util/hashing/HmacTest.java

@@ -0,0 +1,82 @@
+package com.github.glusk2.wse.common.crypto.util.hashing;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+import org.junit.Test;
+
+public class HmacTest {
+
+    @Test
+    public void testOneRFC2104() {
+        ImmutableMessageDigest imd = null;
+        try {
+            imd = new ImdSimpleCopy(MessageDigest.getInstance("MD5"));
+        } catch (NoSuchAlgorithmException e) {
+            fail(e.getMessage());
+        }
+        assertTrue(
+            "Digest doesn't match the test vector.",
+            Arrays.equals(
+                new DigestArgument.BYTES(
+                    "9294727a3638bb1c13f48ef8158bfc9d"
+                ).bytes(),
+                new Hmac(
+                    imd,
+                    new ValueExpansion((byte) 0x0b, 16),
+                    new StringArgument("Hi There")
+                ).bytes()
+            )
+        );
+    }
+
+    @Test
+    public void testTwoRFC2104() {
+        ImmutableMessageDigest imd = null;
+        try {
+            imd = new ImdSimpleCopy(MessageDigest.getInstance("MD5"));
+        } catch (NoSuchAlgorithmException e) {
+            fail(e.getMessage());
+        }
+        assertTrue(
+            "Digest doesn't match the test vector.",
+            Arrays.equals(
+                new DigestArgument.BYTES(
+                    "750c783e6ab0b503eaa86e310a5db738"
+                ).bytes(),
+                new Hmac(
+                    imd,
+                    new StringArgument("Jefe"),
+                    new StringArgument("what do ya want for nothing?") 
+                ).bytes()
+            )
+        );
+    }
+
+    @Test
+    public void testThreeRFC2104() {
+        ImmutableMessageDigest imd = null;
+        try {
+            imd = new ImdSimpleCopy(MessageDigest.getInstance("MD5"));
+        } catch (NoSuchAlgorithmException e) {
+            fail(e.getMessage());
+        }
+        assertTrue(
+            "Digest doesn't match the test vector.",
+            Arrays.equals(
+                new DigestArgument.BYTES(
+                    "56be34521d144c88dbb8c733f0e8b3f6"
+                ).bytes(),
+                new Hmac(
+                    imd,
+                    new ValueExpansion((byte) 0xaa, 16),
+                    new ValueExpansion((byte) 0xdd, 50)
+                ).bytes()
+            )
+        );
+    }
+}