add hw2

node_modules/basic-ftp/dist/netUtils.js

@@ -0,0 +1,67 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.ipIsPrivateV4Address = exports.upgradeSocket = exports.describeAddress = exports.describeTLS = void 0;
+const tls_1 = require("tls");
+/**
+ * Returns a string describing the encryption on a given socket instance.
+ */
+function describeTLS(socket) {
+    if (socket instanceof tls_1.TLSSocket) {
+        const protocol = socket.getProtocol();
+        return protocol ? protocol : "Server socket or disconnected client socket";
+    }
+    return "No encryption";
+}
+exports.describeTLS = describeTLS;
+/**
+ * Returns a string describing the remote address of a socket.
+ */
+function describeAddress(socket) {
+    if (socket.remoteFamily === "IPv6") {
+        return `[${socket.remoteAddress}]:${socket.remotePort}`;
+    }
+    return `${socket.remoteAddress}:${socket.remotePort}`;
+}
+exports.describeAddress = describeAddress;
+/**
+ * Upgrade a socket connection with TLS.
+ */
+function upgradeSocket(socket, options) {
+    return new Promise((resolve, reject) => {
+        const tlsOptions = Object.assign({}, options, {
+            socket
+        });
+        const tlsSocket = (0, tls_1.connect)(tlsOptions, () => {
+            const expectCertificate = tlsOptions.rejectUnauthorized !== false;
+            if (expectCertificate && !tlsSocket.authorized) {
+                reject(tlsSocket.authorizationError);
+            }
+            else {
+                // Remove error listener added below.
+                tlsSocket.removeAllListeners("error");
+                resolve(tlsSocket);
+            }
+        }).once("error", error => {
+            reject(error);
+        });
+    });
+}
+exports.upgradeSocket = upgradeSocket;
+/**
+ * Returns true if an IP is a private address according to https://tools.ietf.org/html/rfc1918#section-3.
+ * This will handle IPv4-mapped IPv6 addresses correctly but return false for all other IPv6 addresses.
+ *
+ * @param ip  The IP as a string, e.g. "192.168.0.1"
+ */
+function ipIsPrivateV4Address(ip = "") {
+    // Handle IPv4-mapped IPv6 addresses like ::ffff:192.168.0.1
+    if (ip.startsWith("::ffff:")) {
+        ip = ip.substr(7); // Strip ::ffff: prefix
+    }
+    const octets = ip.split(".").map(o => parseInt(o, 10));
+    return octets[0] === 10 // 10.0.0.0 - 10.255.255.255
+        || (octets[0] === 172 && octets[1] >= 16 && octets[1] <= 31) // 172.16.0.0 - 172.31.255.255
+        || (octets[0] === 192 && octets[1] === 168) // 192.168.0.0 - 192.168.255.255
+        || ip === "127.0.0.1";
+}
+exports.ipIsPrivateV4Address = ipIsPrivateV4Address;