smulube · November 15, 2017 13:38 · Jun 25, 2013 · Jun 25, 2013 · Jun 25, 2013 · Jun 25, 2013
diff --git a/HmacUtilsTest.java b/HmacUtilsTest.java
@@ -8,7 +8,7 @@
 
 public class HmacUtilsTest {
 
-  @Test
+        @Test
 	public void generatingHmac() {
 		String key = "377f93e5649c31635191c0e22258f5a5744698d3";
 		String value = "0001";

diff --git a/HmacUtils.java b/HmacUtils.java
@@ -10,7 +10,7 @@
 
 public class HmacUtils {
 
-  /**
+        /**
 	 * General hmac method - can pass in any crypto string recognised by
 	 * {@link Mac.getInstance}.
 	 *

diff --git a/gistfile1.java → HmacUtils.java b/gistfile1.java → HmacUtils.java
diff --git a/HmacUtilsTest.java b/HmacUtilsTest.java
@@ -0,0 +1,33 @@
+// Copyright (c) 2003-2013, LogMeIn, Inc. All rights reserved.
+// This is part of Xively4J library, it is under the BSD 3-Clause license.
+package com.xively.client.utils;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class HmacUtilsTest {
+
+  @Test
+	public void generatingHmac() {
+		String key = "377f93e5649c31635191c0e22258f5a5744698d3";
+		String value = "0001";
+		String hmac = "13bf6065634a624104cfa14a1f977bede2aa39d8";
+
+		assertEquals(hmac, HmacUtils.hmacSha1(key, value));
+	}
+
+	@Test
+	public void generatingHmacViaGeneralMethod() {
+		String key = "377f93e5649c31635191c0e22258f5a5744698d3";
+		String value = "0001";
+		String hmac = "13bf6065634a624104cfa14a1f977bede2aa39d8";
+
+		assertEquals(hmac, HmacUtils.hmacSha("HmacSHA1", key, value));
+	}
+
+	@Test(expected = RuntimeException.class)
+	public void invalidCrypto() {
+		HmacUtils.hmacSha("foo", "key", "value");
+	}
+}
diff --git a/gistfile1.java b/gistfile1.java
@@ -0,0 +1,85 @@
+// Copyright (c) 2003-2013, LogMeIn, Inc. All rights reserved.
+// This is part of Xively4J library, it is under the BSD 3-Clause license.
+package com.xively.client.utils;
+
+import java.math.BigInteger;
+import java.security.GeneralSecurityException;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+public class HmacUtils {
+
+  /**
+	 * General hmac method - can pass in any crypto string recognised by
+	 * {@link Mac.getInstance}.
+	 *
+	 * @param crypto
+	 * @param key
+	 * @param value
+	 * @return
+	 */
+	public static String hmacSha(String crypto, String key, String value) {
+		try {
+			byte[] keyBytes = hexStr2Bytes(key);
+
+			Mac hmac;
+			hmac = Mac.getInstance(crypto);
+			SecretKeySpec macKey = new SecretKeySpec(keyBytes, "RAW");
+			hmac.init(macKey);
+			return bytesToHex(hmac.doFinal(value.getBytes()));
+		} catch (GeneralSecurityException gse) {
+			throw new RuntimeException(gse);
+		}
+	}
+
+	/**
+	 * Convenience method to generate the HMAC-SHA1 signatures we are using in
+	 * this application.
+	 *
+	 * @param key
+	 * @param value
+	 * @return
+	 */
+	public static String hmacSha1(String key, String value) {
+		return hmacSha("HmacSHA1", key, value);
+	}
+
+	/**
+	 * Convert hex string into byte array.
+	 *
+	 * @param hex
+	 * @return
+	 */
+	private static byte[] hexStr2Bytes(String hex) {
+		// Adding one byte to get the right conversion
+		// Values starting with "0" can be converted
+		byte[] bArray = new BigInteger("10" + hex, 16).toByteArray();
+
+		// Copy all the REAL bytes, not the "first"
+		byte[] ret = new byte[bArray.length - 1];
+		for (int i = 0; i < ret.length; i++)
+			ret[i] = bArray[i + 1];
+		return ret;
+	}
+
+	/**
+	 *
+	 * Convert a byte array into a hex string
+	 *
+	 * @param bytes
+	 * @return
+	 */
+	private static String bytesToHex(byte[] bytes) {
+		final char[] hexArray = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
+				'9', 'a', 'b', 'c', 'd', 'e', 'f' };
+		char[] hexChars = new char[bytes.length * 2];
+		int v;
+		for (int j = 0; j < bytes.length; j++) {
+			v = bytes[j] & 0xFF;
+			hexChars[j * 2] = hexArray[v >>> 4];
+			hexChars[j * 2 + 1] = hexArray[v & 0x0F];
+		}
+		return new String(hexChars);
+	}
+}