simplify generateExtensions()

src/main/java/com/josh/vku2f/IDSecret.java

@@ -101,8 +101,12 @@ public class IDSecret {
 		Util.arrayCopy(outputBuffer, (short)0, hmac, (short)0, (short)32 );
 	}
 
-	private short generateExtensions(){
-		// 69byte <- EXTENSIONS:10 + PRLAB:5 + HMAC:4 + hmac:32 + CX:2 + cx:16
+	/**
+	 *
+	 * @param extensionBuffer outputBuffer
+	 * @return extension byte string length
+	 */
+	public short generateExtensions(byte[] extensionBuffer){
 		encoder.init(tempBuffer, (short)0, (short) tempBuffer.length);
 		encoder.startMap((short)1);
 		encoder.encodeTextString(Utf8Strings.UTF8_PRLab, (short)0, (short)Utf8Strings.UTF8_PRLab.length);
@@ -111,20 +115,11 @@ public class IDSecret {
 		encoder.encodeByteString(hmac, (short)0, (short)hmac.length );
 		encoder.encodeTextString(Utf8Strings.UTF8_Cx, (short)0, (short)Utf8Strings.UTF8_Cx.length);
 		encoder.encodeByteString(encryptedCx, (short)0, (short)encryptedCx.length);
-
+		extensionBuffer = new byte[encoder.getCurrentOffset()];
+		Util.arrayCopy(tempBuffer, (short)0, extensionBuffer, (short)0, encoder.getCurrentOffset());
 		return encoder.getCurrentOffset();
 	}
 
-	public short getExtensionsLength(){
-		tempBufferLength =  generateExtensions();
-		return tempBufferLength;
-	}
-
-	public short getExtensionsByteString(byte[] outputBuffer, short outputOffset){
-		Util.arrayCopy(tempBuffer, (short)0, outputBuffer, outputOffset, tempBufferLength);
-		return tempBufferLength;
-	}
-
 	/**
 	 *
 	 * @param inputBuffer the buffer copy from