Edit in JSFiddle

var canvas = document.getElementById("myCanvas");
var ctx;
var linkText="http://www.google.com";
var linkX=5;
var linkY=15;
var linkHeight=10;
var linkWidth;
var inLink = false;
 
function draw(){
  canvas = document.getElementById("myCanvas");
  // check if supported
  if(canvas.getContext){
 
    ctx=canvas.getContext("2d");
 
    //clear canvas
    ctx.clearRect(0, 0, canvas.width, canvas.height);
 
    //draw the link
    ctx.font='10px sans-serif';
    ctx.fillStyle = "#0000ff";
    ctx.fillText(linkText,linkX,linkY);
    linkWidth=ctx.measureText(linkText).width;
 
    //add mouse listeners
    canvas.addEventListener("mousemove", on_mousemove, false);
    canvas.addEventListener("click", on_click, false);
 
  }
}
 
//check if the mouse is over the link and change cursor style
function on_mousemove (ev) {
  var x, y;
 
  // Get the mouse position relative to the canvas element.
  if (ev.layerX || ev.layerX) { //for firefox
    x = ev.layerX;
    y = ev.layerY;
  }
  x-=canvas.offsetLeft;
  y-=canvas.offsetTop;
 
  //is the mouse over the link?
  if(x>=linkX && x <= (linkX + linkWidth) &&
     y<=linkY && y>= (linkY-linkHeight)){
      document.body.style.cursor = "pointer";
      inLink=true;
  }
  else{
      document.body.style.cursor = "";
      inLink=false;
  }
}
 
//if the link has been clicked, go to link
function on_click(e) {
  if (inLink)  {
    window.location = linkText;
  }
}
<body onload="draw()">
  <canvas id="myCanvas" width="150" height="200">Canvas not supported.</canvas>
</body>