1 files changed, 84 insertions, 0 deletions
diff --git a/frontend/decryptor.js b/frontend/decryptor.js
new file mode 100644
index 0000000..c37aa42
--- /dev/null
+++ b/frontend/decryptor.js
@@ -0,0 +1,84 @@
+//License: Expat(MIT)
+//Chrisoft Xiong 2017-2018
+var decid;
+function decryptui(id)
+{
+	document.getElementById("decryptui").style.display="block";
+	document.getElementById("keyinp").focus();
+	setTimeout(function(){document.getElementById("decryptui").style.opacity="1";},20);
+	decid=id;
+	document.getElementById("keyhint").innerHTML="Hint: "+document.querySelector(`encrypted[enid="${id}"]`).getAttribute("hint");
+	document.getElementById("keyinp").onkeypress=function(e){if(e.keyCode==13)document.getElementById('btndecrypt').click();}
+}
+function hidedecryptui()
+{
+	document.getElementById("decryptui").style.opacity="0";
+	setTimeout(function(){
+		document.getElementById("decryptui").style.display="none";
+		document.getElementById("keyinp").value="";
+	},500);
+}
+function _decrypt(id,ctr)
+{
+	const aes=aesjs,sha256=Sha256;
+	const e=document.querySelector(`encrypted[enid="${id}"]`);
+	const cont=e.getAttribute("encont");
+	const bc=atob(cont);
+	const b=new Array(bc.length);
+	for(var i=0;i<bc.length;++i)b[i]=bc.charCodeAt(i);
+	const deccont=ctr.decrypt(b);
+	const hash=sha256.hash(aes.utils.hex.fromBytes(deccont),{msgFormat:'hex-bytes'})
+	if(hash!=e.getAttribute("hash"))return false;
+	e.innerHTML=aes.utils.utf8.fromBytes(deccont);
+	e.removeAttribute("encont");
+	return true;
+}
+function _memokey(id,enk)
+{
+	try
+	{
+		const os=localStorage.getItem(`blogkeys${window.location.pathname}`);
+		const o=os&&os.length?JSON.parse(os):[];
+		o[Number(id)]=enk;
+		localStorage.setItem(`blogkeys${window.location.pathname}`,JSON.stringify(o));
+	}catch(e){console.warn(`local storage failed: ${e}`);}
+}
+async function decryptor(id,key)
+{
+	const aes=aesjs,sha256=Sha256;
+	const keyu8=aes.utils.utf8.toBytes(document.getElementById("keyinp").value);
+	const saltu8=aes.utils.utf8.toBytes('hellwhymustiaddsalttothiscrap');
+	const enckey=await new Promise(
+		(resolv,rej)=>
+		{scrypt(keyu8,saltu8,1024,16,2,32,(e,p,k)=>{e?rej(e):k?resolv(k):undefined;});}
+	);
+	const ctr=new aes.ModeOfOperation.ctr(enckey);
+	if(!_decrypt(id,ctr))
+	{
+		alert("The decryption key you have entered could be wrong, please try again.");
+		return;
+	}
+	_memokey(id,enckey);
+	for(let i of document.querySelectorAll('encrypted[encont]'))
+	if(_decrypt(i.getAttribute('enid'),ctr))_memokey(i.getAttribute('enid'),enckey);
+	footnoter();document.getElementById('purgep').style.display='';
+	hidedecryptui();
+}
+function _purgep()
+{
+	try{localStorage.removeItem(`blogkeys${window.location.pathname}`);}
+	catch(e){}
+	location.reload(true);
+}
+function _decryptonload()
+{
+	let o;
+	try
+	{
+		const os=localStorage.getItem(`blogkeys${window.location.pathname}`);
+		o=os&&os.length?JSON.parse(os):[];
+	}catch(e){console.warn(`local storage failed: ${e}`);}
+	for(let i of o.entries())
+	if(i[1]&&i[1].length)_decrypt(Number(i[0]).toString(),new aesjs.ModeOfOperation.ctr(i[1]));
+	if(o.length){footnoter();document.getElementById('purgep').style.display='';}
+}