Add cookie auth example to Mongoose

PUBLISHED_FROM=88bc5059504cfedd078cab277a6d68d1e583fba1

examples/cookie_authentication/Makefile

+PROG = cookie_auth
+include ../examples.mk

examples/cookie_authentication/cookie_auth.c

+// Copyright (c) 2014 Cesanta Software
+// All rights reserved
+
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include "mongoose.h"
+
+static const char *s_http_port = "8000";
+static struct mg_serve_http_opts s_http_server_opts;
+static const char *s_login_uri = "/login.html";
+static const char *s_secret = ":-)";  // Must be known only to server
+
+
+static void generate_ssid(const char *user_name, const char *expiration_date,
+                          char *ssid, size_t ssid_size) {
+  char hash[33];
+  cs_md5(hash,
+         user_name, strlen(user_name),
+         ":", (size_t) 1,
+         expiration_date, strlen(expiration_date),
+         ":", (size_t) 1,
+         s_secret, strlen(s_secret),
+         NULL);
+  snprintf(ssid, ssid_size, "%s|%s|%s", user_name, expiration_date, hash);
+}
+
+static int check_auth(struct http_message *hm) {
+  int authenticated = 0;
+  char ssid[100], calculated_ssid[100], name[100], expire[100];
+
+  if (mg_vcmp(&hm->uri, s_login_uri) == 0) {
+    // Always authenticate requests to login page
+    authenticated = 1;
+  } else {
+    // Look for session ID in the Cookie.
+    // That session ID can be validated against the database that stores
+    // current active sessions.
+    mg_http_parse_header(
+      mg_get_http_header(hm, "Cookie"), "ssid", ssid, sizeof(ssid));
+    if (sscanf(ssid, "%[^|]|%[^|]|", name, expire) == 2) {
+      generate_ssid(name, expire, calculated_ssid, sizeof(calculated_ssid));
+      if (strcmp(ssid, calculated_ssid) == 0) {
+        authenticated = 1;
+      }
+    }
+  }
+
+  return authenticated;
+}
+
+static void check_login_form_submission(struct mg_connection *c,
+                                        struct http_message *hm) {
+  char name[100], password[100], ssid[100], expire[100], expire_epoch[100];
+
+  mg_get_http_var(&hm->body, "name", name, sizeof(name));
+  mg_get_http_var(&hm->body, "password", password, sizeof(password));
+
+  // A real authentication mechanism should be employed here.
+  // Also, the whole site should be served through HTTPS.
+  if (strcmp(name, "Joe") == 0 && strcmp(password, "Doe") == 0) {
+
+    // Generate expiry date
+    time_t t = time(NULL) + 3600;  // Valid for 1 hour
+    snprintf(expire_epoch, sizeof(expire_epoch), "%lu", (unsigned long) t);
+    strftime(expire, sizeof(expire), "%a, %d %b %Y %H:%M:%S GMT", gmtime(&t));
+    generate_ssid(name, expire_epoch, ssid, sizeof(ssid));
+
+    // Set "session id" cookie, there could be some data encoded in it.
+    mg_printf(c,
+              "HTTP/1.1 302 Moved\r\n"
+              "Set-Cookie: ssid=%s; expire=\"%s\"; http-only; HttpOnly;\r\n"
+              "Location: /\r\n\r\n",
+              ssid, expire);
+  } else {
+      mg_printf(c, "%s", "HTTP/1.1 302 Moved\r\nLocation: /\r\n\r\n");
+  }
+}
+
+static void ev_handler(struct mg_connection *c, int ev, void *ev_data) {
+  if (ev == MG_EV_HTTP_REQUEST) {
+    struct http_message *hm = (struct http_message *) ev_data;
+
+    if (mg_vcmp(&hm->uri, s_login_uri) == 0 &&
+        mg_vcmp(&hm->method, "POST") == 0) {
+      check_login_form_submission(c, hm);
+    } else if (check_auth(hm)) {
+      // Authenticated. Serve files.
+      mg_serve_http(c, (struct http_message *) ev_data, s_http_server_opts);
+    } else {
+      // Not authenticated. Redirect to the login page.
+      mg_printf(c, "HTTP/1.1 302 Moved\r\nLocation: %s\r\n\r\n", s_login_uri);
+    }
+  }
+}
+
+int main(void) {
+  struct mg_mgr mgr;
+  struct mg_connection *c;
+
+  mg_mgr_init(&mgr, NULL);
+  c = mg_bind(&mgr, s_http_port, ev_handler);
+
+  if (c == NULL) {
+    printf("Cannot start server on port %s\n", s_http_port);
+    exit(1);
+  }
+
+  // Set up HTTP server parameters
+  mg_set_protocol_http_websocket(c);
+  s_http_server_opts.document_root = ".";  // Serve current directory
+
+  printf("Starting web server on port %s\n", s_http_port);
+  for (;;) {
+    mg_mgr_poll(&mgr, 1000);
+  }
+  mg_mgr_free(&mgr);
+
+  return 0;
+}

examples/cookie_authentication/index.html

+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="utf-8" />
+  <title>WebSocket Test</title>
+  <meta name="viewport" content="width=device-width, initial-scale=1" />
+  <style type="text/css">
+    body {
+      background-color: #cde; margin: 0;
+      padding: 0; font: 14px Helvetica, Arial, sans-serif;
+    }
+    * { outline: none; }
+    div.content {
+      width: 800px; margin: 2em auto; padding: 20px 50px;
+      background-color: #fff; border-radius: 1em;
+    }
+    label { display: inline-block; min-width: 7em; }
+    input { border: 1px solid #ccc; padding: 0.4em; margin: 0 0 10px 0; }
+    a:link, a:visited { color: #69c; text-decoration: none; }
+    @media (max-width: 700px) {
+      body { background-color: #fff; }
+      div.content {
+        width: auto; margin: 0 auto; border-radius: 0; padding: 1em;
+      }
+    }
+</style>
+
+<body>
+  <div class="content">
+    <h1>Mongoose Cookie Base Authentication</h1>
+    <p>This is an index page. Authentication succeeded.</p>
+</body>
+</html>

examples/cookie_authentication/login.html

+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="utf-8" />
+  <title>WebSocket Test</title>
+  <meta name="viewport" content="width=device-width, initial-scale=1" />
+  <style type="text/css">
+    body {
+      background-color: #cde; margin: 0;
+      padding: 0; font: 14px Helvetica, Arial, sans-serif;
+    }
+    * { outline: none; }
+    div.content {
+      width: 800px; margin: 2em auto; padding: 20px 50px;
+      background-color: #fff; border-radius: 1em;
+    }
+    label { display: inline-block; min-width: 7em; }
+    input { border: 1px solid #ccc; padding: 0.4em; margin: 0 0 10px 0; }
+    a:link, a:visited { color: #69c; text-decoration: none; }
+    @media (max-width: 700px) {
+      body { background-color: #fff; }
+      div.content {
+        width: auto; margin: 0 auto; border-radius: 0; padding: 1em;
+      }
+    }
+</style>
+
+<body>
+  <div class="content">
+    <h1>Mongoose Cookie Based Authentication</h1>
+    <p>Use name "Joe", password "Doe" to login.</p>
+    <form method="POST">
+      <div>
+        <label>Name:</label>
+        <input type="text" name="name"/>
+      </div><div>
+        <label>Password:</label>
+        <input type="password" name="password"/>
+      </div><div>
+        <input type="submit" value="Login"/>
+      </div>
+    </form>
+</body>
+</html>