/* * OpenVPN -- An application to securely tunnel IP networks * over a single TCP/UDP port, with support for SSL/TLS-based * session authentication and key exchange, * packet encryption, packet authentication, and * packet compression. * * Copyright (C) 2002-2009 OpenVPN Technologies, Inc. * Copyright (C) 2010 David Sommerseth * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program (see the file COPYING included with this * distribution); if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* * This plugin is similar to simple.c, except it also logs extra information * to stdout for every plugin method called by OpenVPN. The only difference * between this (log_v3.c) and log.c is that this module uses the v3 plug-in * API. * * See the README file for build instructions. */ #include #include #include #define ENABLE_CRYPTO #include "openvpn-plugin.h" /* * Our context, where we keep our state. */ struct plugin_context { const char *username; const char *password; }; /* * Given an environmental variable name, search * the envp array for its value, returning it * if found or NULL otherwise. */ static const char * get_env (const char *name, const char *envp[]) { if (envp) { int i; const int namelen = strlen (name); for (i = 0; envp[i]; ++i) { if (!strncmp (envp[i], name, namelen)) { const char *cp = envp[i] + namelen; if (*cp == '=') return cp + 1; } } } return NULL; } OPENVPN_EXPORT int openvpn_plugin_open_v3 (const int v3structver, struct openvpn_plugin_args_open_in const *args, struct openvpn_plugin_args_open_return *ret) { struct plugin_context *context = NULL; /* Check that we are API compatible */ if( v3structver != OPENVPN_PLUGINv3_STRUCTVER ) { return OPENVPN_PLUGIN_FUNC_ERROR; } if( args->ssl_api != SSLAPI_OPENSSL ) { printf("This plug-in can only be used against OpenVPN with OpenSSL\n"); return OPENVPN_PLUGIN_FUNC_ERROR; } /* Which callbacks to intercept. */ ret->type_mask = OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_UP) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_DOWN) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_ROUTE_UP) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_IPCHANGE) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_TLS_VERIFY) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_CLIENT_CONNECT_V2) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_CLIENT_DISCONNECT) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_LEARN_ADDRESS) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_TLS_FINAL); /* Allocate our context */ context = (struct plugin_context *) calloc (1, sizeof (struct plugin_context)); /* Set the username/password we will require. */ context->username = "foo"; context->password = "bar"; /* Point the global context handle to our newly created context */ ret->handle = (void *) context; return OPENVPN_PLUGIN_FUNC_SUCCESS; } void show (const int type, const char *argv[], const char *envp[]) { size_t i; switch (type) { case OPENVPN_PLUGIN_UP: printf ("OPENVPN_PLUGIN_UP\n"); break; case OPENVPN_PLUGIN_DOWN: printf ("OPENVPN_PLUGIN_DOWN\n"); break; case OPENVPN_PLUGIN_ROUTE_UP: printf ("OPENVPN_PLUGIN_ROUTE_UP\n"); break; case OPENVPN_PLUGIN_IPCHANGE: printf ("OPENVPN_PLUGIN_IPCHANGE\n"); break; case OPENVPN_PLUGIN_TLS_VERIFY: printf ("OPENVPN_PLUGIN_TLS_VERIFY\n"); break; case OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY: printf ("OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY\n"); break; case OPENVPN_PLUGIN_CLIENT_CONNECT_V2: printf ("OPENVPN_PLUGIN_CLIENT_CONNECT_V2\n"); break; case OPENVPN_PLUGIN_CLIENT_DISCONNECT: printf ("OPENVPN_PLUGIN_CLIENT_DISCONNECT\n"); break; case OPENVPN_PLUGIN_LEARN_ADDRESS: printf ("OPENVPN_PLUGIN_LEARN_ADDRESS\n"); break; case OPENVPN_PLUGIN_TLS_FINAL: printf ("OPENVPN_PLUGIN_TLS_FINAL\n"); break; default: printf ("OPENVPN_PLUGIN_?\n"); break; } printf ("ARGV\n"); for (i = 0; argv[i] != NULL; ++i) printf ("%d '%s'\n", (int)i, argv[i]); printf ("ENVP\n"); for (i = 0; envp[i] != NULL; ++i) printf ("%d '%s'\n", (int)i, envp[i]); } static void x509_print_info (X509 *x509crt) { int i, n; int fn_nid; ASN1_OBJECT *fn; ASN1_STRING *val; X509_NAME *x509_name; X509_NAME_ENTRY *ent; const char *objbuf; unsigned char *buf; x509_name = X509_get_subject_name (x509crt); n = X509_NAME_entry_count (x509_name); for (i = 0; i < n; ++i) { ent = X509_NAME_get_entry (x509_name, i); if (!ent) continue; fn = X509_NAME_ENTRY_get_object (ent); if (!fn) continue; val = X509_NAME_ENTRY_get_data (ent); if (!val) continue; fn_nid = OBJ_obj2nid (fn); if (fn_nid == NID_undef) continue; objbuf = OBJ_nid2sn (fn_nid); if (!objbuf) continue; buf = (unsigned char *)1; /* bug in OpenSSL 0.9.6b ASN1_STRING_to_UTF8 requires this workaround */ if (ASN1_STRING_to_UTF8 (&buf, val) <= 0) continue; printf("X509 %s: %s\n", objbuf, (char *)buf); OPENSSL_free (buf); } } OPENVPN_EXPORT int openvpn_plugin_func_v3 (const int version, struct openvpn_plugin_args_func_in const *args, struct openvpn_plugin_args_func_return *retptr) { struct plugin_context *context = (struct plugin_context *) args->handle; printf("\nopenvpn_plugin_func_v3() :::::>> "); show (args->type, args->argv, args->envp); /* Dump some X509 information if we're in the TLS_VERIFY phase */ if ((args->type == OPENVPN_PLUGIN_TLS_VERIFY) && args->current_cert ) { printf("---- X509 Subject information ----\n"); printf("Certificate depth: %i\n", args->current_cert_depth); x509_print_info(args->current_cert); printf("----------------------------------\n"); } /* check entered username/password against what we require */ if (args->type == OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY) { /* get username/password from envp string array */ const char *username = get_env ("username", args->envp); const char *password = get_env ("password", args->envp); if (username && !strcmp (username, context->username) && password && !strcmp (password, context->password)) return OPENVPN_PLUGIN_FUNC_SUCCESS; else return OPENVPN_PLUGIN_FUNC_ERROR; } else return OPENVPN_PLUGIN_FUNC_SUCCESS; } OPENVPN_EXPORT void openvpn_plugin_close_v1 (openvpn_plugin_handle_t handle) { struct plugin_context *context = (struct plugin_context *) handle; free (context); }