I saw many pages talking about how to intercept the HTTP Response from a site. I'm trying this: Chrome Extension - How to get HTTP Response Body? There are no execuble programs... this is my code:
manifest.json:
{
"manifest_version": 2,
"name": "Extension Name",
"description": "Some Desc.",
"version": "1.1",
"browser_action": {
"default_icon": "icon.png",
"default_popup": "index.html"
},
"permissions": [
"activeTab",
"storage",
"tabs",
"https://*.google.com/"
],
"content_scripts": [
{
"matches": ["https://*.google.com/"],
"run_at": "document_start",
"js": ["contentscript.js", "inject.js"]
}
],
"web_accessible_resources": ["injected.js"]
}
index.html:
<html>
<head>
<script src="contentscript.js"></script>
</head>
<body>
<p>HTTP INTERCEPTOR</p>
</body>
</html>
injected.js:
(function(xhr) {
console.log('injeced file');
var XHR = XMLHttpRequest.prototype;
var open = XHR.open;
var send = XHR.send;
var setRequestHeader = XHR.setRequestHeader;
XHR.open = function(method, url) {
this._method = method;
this._url = url;
this._requestHeaders = {};
this._startTime = (new Date()).toISOString();
return open.apply(this, arguments);
};
XHR.setRequestHeader = function(header, value) {
this._requestHeaders[header] = value;
return setRequestHeader.apply(this, arguments);
};
XHR.send = function(postData) {
this.addEventListener('load', function() {
var endTime = (new Date()).toISOString();
var myUrl = this._url ? this._url.toLowerCase() : this._url;
if(myUrl) {
if (postData) {
if (typeof postData === 'string') {
try {
// here you get the REQUEST HEADERS, in JSON format, so you can also use JSON.parse
this._requestHeaders = postData;
} catch(err) {
console.log('Request Header JSON decode failed, transfer_encoding field could be base64');
console.log(err);
}
} else if (typeof postData === 'object' || typeof postData === 'array' || typeof postData === 'number' || typeof postData === 'boolean') {
// do something if you need
}
}
// here you get the RESPONSE HEADERS
var responseHeaders = this.getAllResponseHeaders();
if ( this.responseType != 'blob' && this.responseText) {
// responseText is string or null
try {
// here you get RESPONSE TEXT (BODY), in JSON format, so you can use JSON.parse
var arr = this.responseText;
// printing url, request headers, response headers, response body, to console
console.log(this._url);
console.log(JSON.parse(this._requestHeaders));
console.log(responseHeaders);
console.log(JSON.parse(arr));
} catch(err) {
console.log("Error in responseType try catch");
console.log(err);
}
}
}
});
return send.apply(this, arguments);
};
})(XMLHttpRequest);
inject.js I set a timeout so I can enable the debugger:
/**
* code in inject.js
* added "web_accessible_resources": ["injected.js"] to manifest.json
*/
setTimeout(function() {
var s = document.createElement('script');
s.src = chrome.extension.getURL('injected.js');
s.onload = function() {
this.remove();
console.log('remove');
};
(document.head || document.documentElement).appendChild(s);
}, 10000);
Why the code is not injected into https://www.google.com/? Inspecting the DOM I don't see the code... the code runs and xhr is started but the methods open, setRequestHeader and send are never called.
