Added buffer variants for crc 8/16/32

lib/crc.js

@@ -253,6 +253,14 @@
 		return crc;
 	};
 
+  function crc8Buffer(buf) {
+    var crc = 0;
+    for (var i = 0, len = buf.length; i < len; ++i) {
+      crc = crc8Add(crc, buf[i]);
+    }
+    return crc;
+  }
+
 	function crcArc(str)
 	{
 		var i,
@@ -279,6 +287,14 @@
 		return crc;
 	};
 
+  function crc16Buffer(buf) {
+    var crc = 0;
+    for (var i = 0, len = buf.length; i < len; ++i) {
+      crc = crc16Add(crc, buf[i]);
+    }
+    return crc;
+  }
+
 	function fcs16(str)
 	{
 		var i,
@@ -305,6 +321,14 @@
 		return crc^0xFFFFFFFF;
 	};
 
+  function crc32Buffer(buf) {
+    var crc = 0xFFFFFFFF;
+    for (var i = 0, len = buf.length; i < len; ++i) {
+      crc = crc32Add(crc, buf[i]);
+    }
+    return crc ^ 0xFFFFFFFF;
+  }
+
 	/**
 	 * Convert value as 8-bit unsigned integer to 2 digit hexadecimal number.
 	 */
@@ -357,6 +381,11 @@
 		'crc32'		: crc32,
 		'hex8'		: hex8,
 		'hex16'		: hex16,
-		'hex32'		: hex32
+		'hex32'		: hex32,
+		'buffer'  : {
+		  crc8: crc8Buffer,
+		  crc16: crc16Buffer,
+		  crc32: crc32Buffer
+		}
 	};
 })();

test/crc.js

@@ -6,18 +6,30 @@ describe('crc8()', function(){
   it('should work with strings', function(){
     crc.crc8('hello world').should.equal(64);
   })
+
+  it('should work with Buffers', function(){
+    crc.buffer.crc8(new Buffer('hello world')).should.equal(64);
+  })
 })
 
 describe('crc16()', function(){
   it('should work with strings', function(){
     crc.crc16('hello world').should.equal(15332);
   })
+
+  it('should work with Buffers', function(){
+    crc.buffer.crc16(new Buffer('hello world')).should.equal(15332);
+  })
 })
 
 describe('crc32()', function(){
   it('should work with strings', function(){
     crc.crc32('hello world').should.equal(222957957);
   })
+
+  it('should work with Buffers', function(){
+    crc.buffer.crc32(new Buffer('hello world')).should.equal(222957957);
+  })
 })
 
 describe('crcArc()', function(){