kakaotalk_analysis/scripts/frida/debug_secret_chat.js
2024-01-02 17:55:10 +01:00

260 lines
8.3 KiB
JavaScript

/*
Hook various Secret Chat methods of KakaoTalk 10.4.3.
*/
const locoKey = Java.array(
"byte",
[
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
]
);
const patchLocoKey = true;
const locoFileNames = [
"V2SLSink.kt",
"V2SLSource.kt",
"V2SLHandshake.kt",
"LocoV2SLSocket.kt",
];
const enableStacktracePrinting = false;
var StringCls = null;
Java.perform(function () {
StringCls = Java.use("java.lang.String");
hookKeyGeneratorGenerateKey();
hookSharedSecretStore();
hookLocoCipherHelper_GenerateRSAPrivateKey();
hookLocoCipherHelper_GenerateRSAPublicKey();
hookAESCTRHelper_GenerateIV();
hookSecretChatHelper();
hookLocoPubKeyInfo();
hookTalkLocoPKStore();
printAESCTRKeySet();
});
function hookKeyGeneratorGenerateKey() {
var generateKey = Java.use("javax.crypto.KeyGenerator")[
"generateKey"
].overload();
generateKey.implementation = function () {
var tmp = this.generateKey();
var caller = Java.use("java.lang.Exception").$new().getStackTrace()[1];
const secretKeySpec = Java.cast(
tmp,
Java.use("javax.crypto.spec.SecretKeySpec")
);
const encodedKey = secretKeySpec.getEncoded();
if (locoFileNames.includes(caller.getFileName())) {
// console.log("[KeyGenerator.generateKey()]: Object: " + tmp);
console.log("Caller: " + caller.getFileName());
// dumpByteArray("[KeyGenerator.generateKey()]: Key", encodedKey);
var base64_key = Java.use("android.util.Base64").encodeToString(
encodedKey,
0
);
console.log("Generated key: " + base64_key);
if (enableStacktracePrinting) {
printStacktrace();
}
}
if (patchLocoKey) {
dumpByteArray("Patching LOCO AES key with key", locoKey);
const SecretKeySpec = Java.use("javax.crypto.spec.SecretKeySpec");
var fakeKey = SecretKeySpec.$new(locoKey, "AES");
tmp = fakeKey;
}
console.log("##############################################");
return tmp;
};
}
function hookSharedSecretStore() {
var locoCipherHelper = Java.use("com.kakao.talk.secret.LocoCipherHelper$e")[
"$init"
].overload("java.lang.String", "long");
locoCipherHelper.implementation = function (arg0, arg1) {
var tmp = this.$init(arg0, arg1);
var caller = Java.use("java.lang.Exception").$new().getStackTrace()[1];
console.log("Secret Chat shared secret: " + arg0);
console.log("Secret Chat seed for nonce: " + arg1);
console.log(this.toString());
console.log("Caller: " + caller.getFileName());
console.log("##############################################");
};
}
function hookLocoCipherHelper_GenerateRSAPrivateKey() {
var locoCipherHelper = Java.use("com.kakao.talk.secret.LocoCipherHelper")[
"e"
].overload("java.lang.String");
locoCipherHelper.implementation = function (arg0) {
var caller = Java.use("java.lang.Exception").$new().getStackTrace()[1];
console.log("Caller: " + caller.getFileName());
console.log("Generated RSA private key: " + arg0);
if (enableStacktracePrinting) {
printStacktrace();
}
console.log("##############################################");
return locoCipherHelper.call(this, arg0);
};
}
function hookLocoCipherHelper_GenerateRSAPublicKey() {
var locoCipherHelper = Java.use("com.kakao.talk.secret.LocoCipherHelper")[
"f"
].overload("java.lang.String");
locoCipherHelper.implementation = function (arg0) {
var caller = Java.use("java.lang.Exception").$new().getStackTrace()[1];
console.log("Caller: " + caller.getFileName());
console.log("Generated RSA public key: " + arg0);
if (enableStacktracePrinting) {
printStacktrace();
}
console.log("##############################################");
return locoCipherHelper.call(this, arg0);
};
}
function hookLocoPubKeyInfo() {
var locoPubKeyInfo = Java.use("t41.n")["$init"].overload(
"com.kakao.talk.loco.protocol.LocoBody"
);
locoPubKeyInfo.implementation = function (locoBody) {
var tmp = this.$init(locoBody);
console.log("locoPubKeyInfo called!");
var caller = Java.use("java.lang.Exception").$new().getStackTrace()[1];
console.log("Caller: " + caller.getFileName());
console.log(locoBody);
console.log("##############################################");
};
}
function hookSecretChatHelper() {
var secretChatHelper = Java.use("com.kakao.talk.secret.b$e")["b"].overload(
"com.kakao.talk.secret.b$d"
);
secretChatHelper.implementation = function (arg0) {
console.log("secretChatHelper3 called!");
var caller = Java.use("java.lang.Exception").$new().getStackTrace()[1];
console.log(caller.getFileName());
console.log(this.a);
console.log("##############################################");
return secretChatHelper.call(this, arg0);
};
}
function hookTalkLocoPKStore() {
var talkLocoPKStore = Java.use("yl1.x3$a")["toString"].overload();
talkLocoPKStore.implementation = function () {
console.log("TalkLocoPKStore class called!");
var caller = Java.use("java.lang.Exception").$new().getStackTrace()[1];
console.log("Caller: " + caller.getFileName());
var ret = talkLocoPKStore.call(this);
console.log(ret);
console.log("##############################################");
return talkLocoPKStore.call(this);
};
}
function hookAESCTRHelper_GenerateIV() {
var AESCTRHelper = Java.use("d20.a")["b"].overload(
"java.lang.String",
"[B",
"int",
"javax.crypto.spec.PBEKeySpec"
);
AESCTRHelper.implementation = function (arg0, arg1, arg2, arg3) {
console.log("AESCTRHelper class called!");
var caller = Java.use("java.lang.Exception").$new().getStackTrace()[1];
console.log("Caller: " + caller.getFileName());
dumpByteArray("Generated IV", arg1);
console.log("##############################################");
return AESCTRHelper.call(this, arg0, arg1, arg2, arg3);
};
}
function printAESCTRKeySet() {
var AESCTRKeySet = Java.use("d20.b")["$init"].overload("[B", "[B", "[B");
AESCTRKeySet.implementation = function (arg0, arg1, arg2) {
console.log("AESCTRKeySet class called!");
var caller = Java.use("java.lang.Exception").$new().getStackTrace()[1];
console.log("Caller: " + caller.getFileName());
dumpByteArray("Secret key", arg0);
dumpByteArray("IV", arg1);
dumpByteArray("arg2", arg2);
console.log("##############################################");
return AESCTRKeySet.call(this, arg0, arg1, arg2);
};
}
function printStacktrace() {
var stacktrace = Java.use("android.util.Log")
.getStackTraceString(Java.use("java.lang.Exception").$new())
.replace("java.lang.Exception", "");
console.log(stacktrace);
}
function dumpByteArray(title, byteArr) {
if (byteArr != null) {
try {
var buff = new ArrayBuffer(byteArr.length);
var dtv = new DataView(buff);
for (var i = 0; i < byteArr.length; i++) {
/*
Frida sucks sometimes and returns different byteArr.length between ArrayBuffer(byteArr.length) and for(..; i < byteArr.length;..).
It occurred even when Array.copyOf was done to work on copy.
*/
dtv.setUint8(i, byteArr[i]);
}
console.log(title + ":\n");
console.log(_hexdumpJS(dtv.buffer, 0, byteArr.length));
} catch (error) {
console.log("Exception has occured in hexdump");
}
} else {
console.log("byteArr is null!");
}
}
function _hexdumpJS(arrayBuffer, offset, length) {
var view = new DataView(arrayBuffer);
offset = offset || 0;
length = length || arrayBuffer.byteLength;
var out =
_fillUp("Offset", 8, " ") +
" 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F\n";
var row = "";
for (var i = 0; i < length; i += 16) {
row += _fillUp(offset.toString(16).toUpperCase(), 8, "0") + " ";
var n = Math.min(16, length - offset);
var string = "";
for (var j = 0; j < 16; ++j) {
if (j < n) {
var value = view.getUint8(offset);
string += value >= 32 && value < 128 ? String.fromCharCode(value) : ".";
row += _fillUp(value.toString(16).toUpperCase(), 2, "0") + " ";
offset++;
} else {
row += " ";
string += " ";
}
}
row += " " + string + "\n";
}
out += row;
return out;
}
function _fillUp(value, count, fillWith) {
var l = count - value.length;
var ret = "";
while (--l > -1) ret += fillWith;
return ret + value;
}