JLU CAS Login snippet (Does Not Work)

jlu_cas.kt

        // Build an client that doesn't follow redirect
        val okhttpNoRedirect = okhttp.newBuilder()
            .followRedirects(false)
            .build()

        if (!verifyUserCredentials()) {
            state._loginState.value = LoginState.NoSessionData
            return
        }
        state._loginState.value = LoginState.LoggingIn

        val initialReq = Request.Builder()
            .url("https://ehall.jlu.edu.cn")
            .get()
            .build()
        var resp = okhttpNoRedirect.newCall(initialReq).await()
        var respBody = ""
        var JsessionId = ""
        val initialReqCookies = mutableMapOf<String, String>()
        Log.i("LOGIN", "First hop: ${resp.code} Redirect: ${resp.isRedirect}")
        while (resp.isRedirect) {
            // Find JSESSIONID in all the redirects
            if (JsessionId == "") {
                JsessionId = resp.headers.find {
                    it.first == "Set-Cookie" && it.second.startsWith("JSESSIONID")
                }?.second ?: ""
                if (JsessionId != "") {
                    Log.i("LOGIN", JsessionId)
                }
            }

            // Obtain cookies
            resp.headers.forEach {
                if (it.first == "Set-Cookie") {
                    val cookieVal = it.second.substringAfter('=').substringBefore(';')
                    val cookieName = it.second.substringBefore('=')
                    initialReqCookies[cookieName] = cookieVal
                }
            }

            // Not hitting cookie? Handle redirects
//            if (!loginResp.isSuccessful) {
//                Log.e("LOGIN", "Login failed. Code = ${resp.code}, Message = ${resp.message}")
//                state._loginState.value = LoginState.LoginFailed
//                return
//            }

            // Redirect
            var target = resp.headers["Location"]!!
            if (!target.startsWith("https"))
                target = "https://${resp.request.url.host}$target"
            Log.i("LOGIN", "Resolve redirect ${resp.code} -> $target")
            val loginReq = Request.Builder()
                .url(target)
                .addHeader("Referer", resp.request.url.toString())
                .addHeader(
                    "Cookie",
                    initialReqCookies.map { "${it.key}=${it.value}; " }
                        .fold("") { acc, s -> acc + s })
                .get()
                .build()
            resp = okhttpNoRedirect.newCall(loginReq).await()
            respBody = AsyncReadResponse(resp.body)
            Log.d("LOGIN", respBody)
        }



        if (!resp.isSuccessful) {
            Log.e("LOGIN", "Initial request failed. Code = ${resp.code}, Message = ${resp.message}")
            state._loginState.value = LoginState.LoginInternalError
            return
        }

        // We should be getting a login page response here with server side rendered session "lt"
        // Find "lt" in response with a simple regex
        val ltMatcher = """<input.+id="lt".+value="(.+)".+>""".toRegex()
        val ltMatches = ltMatcher.find(respBody)
        if (ltMatches == null) {
            Log.e("LOGIN", "Cannot match \"lt\"")
            state._loginState.value = LoginState.LoginInternalError
            return
        }
        val ltValue = ltMatches.groups[1]!!.value
        Log.d("LOGIN", "lt=${ltValue}")

        // "execution" is also needed
        val execMatcher = """<input.+name="execution".+value="(.+)".+>""".toRegex()
        val execMatches = execMatcher.find(respBody)
        if (execMatches == null) {
            Log.e("LOGIN", "Cannot match \"execution\"")
            state._loginState.value = LoginState.LoginInternalError
            return
        }
        val execValue = execMatches.groups[1]!!.value
        Log.d("LOGIN", "execution=${execValue}")

        // Find where should we post the form to
        val postActionMatcher = """<form.+action="(.+)".+>""".toRegex()
        val postActionMatches = postActionMatcher.find(respBody)
        if (postActionMatches == null) {
            Log.e("LOGIN", "Cannot match \"action\"")
            state._loginState.value = LoginState.LoginInternalError
            return
        }
//        var postAction = postActionMatches.groups[1]!!.value
//        postAction = URLDecoder.decode(postAction, "UTF-8")
//        Log.d("LOGIN", "action=${postAction}")

        // Concatenate and encrypt
        val username = pref.getString("Username", "")!!
        val password = pref.getString("Password", "")!!
        val encryptValue = username + password + ltValue
        val encrypted = crypto.strEnc(encryptValue, "1", "2", "3")

        val loginForm = FormBody.Builder()
            .add("rsa", encrypted)
            .add("ul", username.length.toString())
            .add("pl", password.length.toString())
            .add("sl", "0")
            .add("lt", ltValue)
            .add("execution", execValue)
            .add("_eventId", "submit")
            .build()
        val loginHeader = Headers.Builder()
            .add("Content-Type", "application/x-www-form-urlencoded")
//            .add("Referer", resp.request.url.toString())
//            .add(
//                "Cookie",
//                initialReqCookies.map { "${it.key}=${it.value}; " }
//                    .fold("") { acc, s -> acc + s })
            .build()
        val loginReq = Request.Builder()
            .url("https://cas.jlu.edu.cn/tpass/login?service=https://ehall.jlu.edu.cn")
            .headers(loginHeader)
            .post(loginForm)
            .build()

        // Perform login
        var loginResp = okhttp.newCall(loginReq).await()
        Log.d("LOGIN", "Login response ${loginResp.code}")
        Log.d("LOGIN", AsyncReadResponse(loginResp.body))