/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */ /* * Copyright 1994 by OpenVision Technologies, Inc. * * Permission to use, copy, modify, distribute, and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appears in all copies and * that both that copyright notice and this permission notice appear in * supporting documentation, and that the name of OpenVision not be used * in advertising or publicity pertaining to distribution of the software * without specific, written prior permission. OpenVision makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. * * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */ /* * Copyright (C) 2004,2008 by the Massachusetts Institute of Technology. * All rights reserved. * * Export of this software from the United States of America may * require a specific license from the United States Government. * It is the responsibility of any person or organization contemplating * export to obtain such a license before exporting. * * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and * distribute this software and its documentation for any purpose and * without fee is hereby granted, provided that the above copyright * notice appear in all copies and that both that copyright notice and * this permission notice appear in supporting documentation, and that * the name of M.I.T. not be used in advertising or publicity pertaining * to distribution of the software without specific, written prior * permission. Furthermore if you modify this software you must label * your software as modified software and not distribute it in such a * fashion that it might be confused with the original M.I.T. software. * M.I.T. makes no representations about the suitability of * this software for any purpose. It is provided "as is" without express * or implied warranty. */ #include "autoconf.h" #include #ifdef _WIN32 #include #include #else #include #include #include #include #include #include #endif #ifdef HAVE_UNISTD_H #include #endif #include #include #include #include "gss-misc.h" #include "port-sockets.h" #ifdef HAVE_STRING_H #include #else #include #endif static void usage() { fprintf(stderr, "Usage: gss-server [-port port] [-verbose] [-once]"); #ifdef _WIN32 fprintf(stderr, " [-threads num]"); #endif fprintf(stderr, "\n"); fprintf(stderr, " [-inetd] [-export] [-logfile file] " "service_name\n"); exit(1); } FILE *logfile; int verbose = 0; /* * Function: server_acquire_creds * * Purpose: imports a service name and acquires credentials for it * * Arguments: * * service_name (r) the ASCII service name * server_creds (w) the GSS-API service credentials * * Returns: 0 on success, -1 on failure * * Effects: * * The service name is imported with gss_import_name, and service * credentials are acquired with gss_acquire_cred. If either operation * fails, an error message is displayed and -1 is returned; otherwise, * 0 is returned. */ static int server_acquire_creds(char *service_name, gss_cred_id_t *server_creds) { gss_buffer_desc name_buf; gss_name_t server_name; OM_uint32 maj_stat, min_stat; name_buf.value = service_name; name_buf.length = strlen(name_buf.value) + 1; maj_stat = gss_import_name(&min_stat, &name_buf, (gss_OID)gss_nt_service_name, &server_name); if (maj_stat != GSS_S_COMPLETE) { display_status("importing name", maj_stat, min_stat); return -1; } maj_stat = gss_acquire_cred(&min_stat, server_name, 0, GSS_C_NULL_OID_SET, GSS_C_ACCEPT, server_creds, NULL, NULL); if (maj_stat != GSS_S_COMPLETE) { display_status("acquiring credentials", maj_stat, min_stat); return -1; } (void)gss_release_name(&min_stat, &server_name); return 0; } /* * Function: server_establish_context * * Purpose: establishses a GSS-API context as a specified service with * an incoming client, and returns the context handle and associated * client name * * Arguments: * * s (r) an established TCP connection to the client * service_creds (r) server credentials, from gss_acquire_cred * context (w) the established GSS-API context * client_name (w) the client's ASCII name * * Returns: 0 on success, -1 on failure * * Effects: * * Any valid client request is accepted. If a context is established, * its handle is returned in context and the client name is returned * in client_name and 0 is returned. If unsuccessful, an error * message is displayed and -1 is returned. */ static int server_establish_context(int s, gss_cred_id_t server_creds, gss_ctx_id_t *context, gss_buffer_t client_name, OM_uint32 *ret_flags) { gss_buffer_desc send_tok, recv_tok, oid_name; gss_name_t client; gss_OID doid; OM_uint32 maj_stat, min_stat, acc_sec_min_stat; int token_flags; if (recv_token(s, &token_flags, &recv_tok) < 0) return -1; if (recv_tok.value) { free(recv_tok.value); recv_tok.value = NULL; } if (!(token_flags & TOKEN_NOOP)) { if (logfile) { fprintf(logfile, "Expected NOOP token, got %d token instead\n", token_flags); } return -1; } *context = GSS_C_NO_CONTEXT; if (token_flags & TOKEN_CONTEXT_NEXT) { do { if (recv_token(s, &token_flags, &recv_tok) < 0) return -1; if (verbose && logfile) { fprintf(logfile, "Received token (size=%d): \n", (int)recv_tok.length); print_token(&recv_tok); } maj_stat = gss_accept_sec_context(&acc_sec_min_stat, context, server_creds, &recv_tok, GSS_C_NO_CHANNEL_BINDINGS, &client, &doid, &send_tok, ret_flags, NULL, NULL); if (recv_tok.value) { free(recv_tok.value); recv_tok.value = NULL; } if (send_tok.length != 0) { if (verbose && logfile) { fprintf(logfile, "Sending accept_sec_context token (size=%d):\n", (int)send_tok.length); print_token(&send_tok); } if (send_token(s, TOKEN_CONTEXT, &send_tok) < 0) { if (logfile) fprintf(logfile, "failure sending token\n"); return -1; } (void)gss_release_buffer(&min_stat, &send_tok); } if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED) { display_status("accepting context", maj_stat, acc_sec_min_stat); if (*context != GSS_C_NO_CONTEXT) { gss_delete_sec_context(&min_stat, context, GSS_C_NO_BUFFER); } return -1; } if (verbose && logfile) { if (maj_stat == GSS_S_CONTINUE_NEEDED) fprintf(logfile, "continue needed...\n"); else fprintf(logfile, "\n"); fflush(logfile); } } while (maj_stat == GSS_S_CONTINUE_NEEDED); /* display the flags */ display_ctx_flags(*ret_flags); if (verbose && logfile) { maj_stat = gss_oid_to_str(&min_stat, doid, &oid_name); if (maj_stat != GSS_S_COMPLETE) { display_status("converting oid->string", maj_stat, min_stat); return -1; } fprintf(logfile, "Accepted connection using mechanism OID %.*s.\n", (int)oid_name.length, (char *)oid_name.value); (void)gss_release_buffer(&min_stat, &oid_name); } maj_stat = gss_display_name(&min_stat, client, client_name, &doid); if (maj_stat != GSS_S_COMPLETE) { display_status("displaying name", maj_stat, min_stat); return -1; } maj_stat = gss_release_name(&min_stat, &client); if (maj_stat != GSS_S_COMPLETE) { display_status("releasing name", maj_stat, min_stat); return -1; } } else { client_name->length = *ret_flags = 0; if (logfile) fprintf(logfile, "Accepted unauthenticated connection.\n"); } return 0; } /* * Function: create_socket * * Purpose: Opens a listening TCP socket. * * Arguments: * * port (r) the port number on which to listen * * Returns: the listening socket file descriptor, or -1 on failure * * Effects: * * A listening socket on the specified port and created and returned. * On error, an error message is displayed and -1 is returned. */ static int create_socket(u_short port) { struct sockaddr_in saddr; int s, on = 1; saddr.sin_family = AF_INET; saddr.sin_port = htons(port); saddr.sin_addr.s_addr = INADDR_ANY; s = socket(AF_INET, SOCK_STREAM, 0); if (s < 0) { perror("creating socket"); return -1; } /* Let the socket be reused right away. */ (void)setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on)); if (bind(s, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) { perror("binding socket"); (void)close(s); return -1; } if (listen(s, 5) < 0) { perror("listening on socket"); (void)close(s); return -1; } return s; } static float timeval_subtract(struct timeval *tv1, struct timeval *tv2) { return ((tv1->tv_sec - tv2->tv_sec) + ((float)(tv1->tv_usec - tv2->tv_usec)) / 1000000); } /* * Yes, yes, this isn't the best place for doing this test. * DO NOT REMOVE THIS UNTIL A BETTER TEST HAS BEEN WRITTEN, THOUGH. * -TYT */ static int test_import_export_context(gss_ctx_id_t *context) { OM_uint32 min_stat, maj_stat; gss_buffer_desc context_token, copied_token; struct timeval tm1, tm2; /* Attempt to save and then restore the context. */ gettimeofday(&tm1, (struct timezone *)0); maj_stat = gss_export_sec_context(&min_stat, context, &context_token); if (maj_stat != GSS_S_COMPLETE) { display_status("exporting context", maj_stat, min_stat); return 1; } gettimeofday(&tm2, NULL); if (verbose && logfile) { fprintf(logfile, "Exported context: %d bytes, %7.4f seconds\n", (int)context_token.length, timeval_subtract(&tm2, &tm1)); } copied_token.length = context_token.length; copied_token.value = malloc(context_token.length); if (copied_token.value == 0) { if (logfile) { fprintf(logfile, "Couldn't allocate memory to copy context " "token.\n"); } return 1; } memcpy(copied_token.value, context_token.value, copied_token.length); maj_stat = gss_import_sec_context(&min_stat, &copied_token, context); if (maj_stat != GSS_S_COMPLETE) { display_status("importing context", maj_stat, min_stat); return 1; } free(copied_token.value); gettimeofday(&tm1, NULL); if (verbose && logfile) { fprintf(logfile, "Importing context: %7.4f seconds\n", timeval_subtract(&tm1, &tm2)); } (void)gss_release_buffer(&min_stat, &context_token); return 0; } /* * Function: sign_server * * Purpose: Performs the "sign" service. * * Arguments: * * s (r) a TCP socket on which a connection has been * accept()ed * service_name (r) the ASCII name of the GSS-API service to * establish a context as * export (r) whether to test context exporting * * Returns: -1 on error * * Effects: * * sign_server establishes a context, and performs a single sign request. * * A sign request is a single GSS-API sealed token. The token is * unsealed and a signature block, produced with gss_sign, is returned * to the sender. The context is the destroyed and the connection * closed. * * If any error occurs, -1 is returned. */ static int sign_server(int s, gss_cred_id_t server_creds, int export) { gss_buffer_desc client_name, xmit_buf, msg_buf; gss_ctx_id_t context; OM_uint32 maj_stat, min_stat, ret_flags; int i, conf_state, token_flags; char *cp; /* Establish a context with the client */ if (server_establish_context(s, server_creds, &context, &client_name, &ret_flags) < 0) return -1; if (context == GSS_C_NO_CONTEXT) { printf("Accepted unauthenticated connection.\n"); } else { printf("Accepted connection: \"%.*s\"\n", (int)client_name.length, (char *)client_name.value); (void)gss_release_buffer(&min_stat, &client_name); if (export) { for (i = 0; i < 3; i++) { if (test_import_export_context(&context)) return -1; } } } do { /* Receive the message token */ if (recv_token(s, &token_flags, &xmit_buf) < 0) return -1; if (token_flags & TOKEN_NOOP) { if (logfile) fprintf(logfile, "NOOP token\n"); if (xmit_buf.value) { free(xmit_buf.value); xmit_buf.value = 0; } break; } if (verbose && logfile) { fprintf(logfile, "Message token (flags=%d):\n", token_flags); print_token(&xmit_buf); } if (context == GSS_C_NO_CONTEXT && (token_flags & (TOKEN_WRAPPED | TOKEN_ENCRYPTED | TOKEN_SEND_MIC))) { if (logfile) { fprintf(logfile, "Unauthenticated client requested " "authenticated services!\n"); } if (xmit_buf.value) { free(xmit_buf.value); xmit_buf.value = 0; } return -1; } if (token_flags & TOKEN_WRAPPED) { maj_stat = gss_unwrap(&min_stat, context, &xmit_buf, &msg_buf, &conf_state, NULL); if (maj_stat != GSS_S_COMPLETE) { display_status("unsealing message", maj_stat, min_stat); if (xmit_buf.value) { free(xmit_buf.value); xmit_buf.value = 0; } return -1; } else if (!conf_state && (token_flags & TOKEN_ENCRYPTED)) { fprintf(stderr, "Warning! Message not encrypted.\n"); } if (xmit_buf.value) { free(xmit_buf.value); xmit_buf.value = 0; } } else { msg_buf = xmit_buf; } if (logfile) { fprintf(logfile, "Received message: "); cp = msg_buf.value; if (isprint((unsigned char)cp[0]) && isprint((unsigned char)cp[1])) { fprintf(logfile, "\"%.*s\"\n", (int)msg_buf.length, (char *)msg_buf.value); } else { fprintf(logfile, "\n"); print_token(&msg_buf); } } if (token_flags & TOKEN_SEND_MIC) { /* Produce a signature block for the message. */ maj_stat = gss_get_mic(&min_stat, context, GSS_C_QOP_DEFAULT, &msg_buf, &xmit_buf); if (maj_stat != GSS_S_COMPLETE) { display_status("signing message", maj_stat, min_stat); return -1; } if (msg_buf.value) { free(msg_buf.value); msg_buf.value = 0; } /* Send the signature block to the client. */ if (send_token(s, TOKEN_MIC, &xmit_buf) < 0) return -1; if (xmit_buf.value) { free(xmit_buf.value); xmit_buf.value = 0; } } else { if (msg_buf.value) { free(msg_buf.value); msg_buf.value = 0; } if (send_token(s, TOKEN_NOOP, empty_token) < 0) return -1; } } while (1 /* loop will break if NOOP received */); if (context != GSS_C_NO_CONTEXT) { /* Delete context. */ maj_stat = gss_delete_sec_context(&min_stat, &context, NULL); if (maj_stat != GSS_S_COMPLETE) { display_status("deleting context", maj_stat, min_stat); return -1; } } if (logfile) fflush(logfile); return 0; } static int max_threads = 1; #ifdef _WIN32 static thread_count = 0; static HANDLE hMutex = NULL; static HANDLE hEvent = NULL; void init_handles(void) { hMutex = CreateMutex(NULL, FALSE, NULL); hEvent = CreateEvent(NULL, FALSE, FALSE, NULL); } void cleanup_handles(void) { CloseHandle(hMutex); CloseHandle(hEvent); } BOOL wait_and_increment_thread_counter(void) { for (;;) { if (WaitForSingleObject(hMutex, INFINITE) == WAIT_OBJECT_0) { if (thread_count < max_threads) { thread_count++; ReleaseMutex(hMutex); return TRUE; } else { ReleaseMutex(hMutex); if (WaitForSingleObject(hEvent, INFINITE) == WAIT_OBJECT_0) continue; else return FALSE; } } else { return FALSE; } } } BOOL decrement_and_signal_thread_counter(void) { if (WaitForSingleObject(hMutex, INFINITE) == WAIT_OBJECT_0) { if (thread_count == max_threads) SetEvent(hEvent); thread_count--; ReleaseMutex(hMutex); return TRUE; } else { return FALSE; } } #else /* assume pthread */ static pthread_mutex_t counter_mutex = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t counter_cond = PTHREAD_COND_INITIALIZER; int counter = 0; static int wait_and_increment_thread_counter(void) { int err; err = pthread_mutex_lock(&counter_mutex); if (err) { perror("pthread_mutex_lock"); return 0; } if (counter == max_threads) { err = pthread_cond_wait(&counter_cond, &counter_mutex); if (err) { pthread_mutex_unlock(&counter_mutex); perror("pthread_cond_wait"); return 0; } } counter++; pthread_mutex_unlock(&counter_mutex); return 1; } static void decrement_and_signal_thread_counter(void) { int err; err = pthread_mutex_lock(&counter_mutex); if (err) { perror("pthread_mutex_lock"); return; } if (counter == max_threads) pthread_cond_broadcast(&counter_cond); counter--; pthread_mutex_unlock(&counter_mutex); } #endif struct _work_plan { int s; gss_cred_id_t server_creds; int export; }; static void * worker_bee(void *param) { struct _work_plan *work = param; /* This return value is not checked, because there's not really anything to * do if it fails. */ sign_server(work->s, work->server_creds, work->export); closesocket(work->s); free(work); #if defined _WIN32 || 1 if (max_threads > 1) decrement_and_signal_thread_counter(); #endif return NULL; } int main(int argc, char **argv) { char *service_name; gss_cred_id_t server_creds; OM_uint32 min_stat; u_short port = 4444; int once = 0; int do_inetd = 0; int export = 0; signal(SIGPIPE, SIG_IGN); logfile = stdout; display_file = stdout; argc--; argv++; while (argc) { if (strcmp(*argv, "-port") == 0) { argc--; argv++; if (!argc) usage(); port = atoi(*argv); } else if (strcmp(*argv, "-threads") == 0) { argc--; argv++; if (!argc) usage(); max_threads = atoi(*argv); } else if (strcmp(*argv, "-verbose") == 0) { verbose = 1; } else if (strcmp(*argv, "-once") == 0) { once = 1; } else if (strcmp(*argv, "-inetd") == 0) { do_inetd = 1; } else if (strcmp(*argv, "-export") == 0) { export = 1; } else if (strcmp(*argv, "-logfile") == 0) { argc--; argv++; if (!argc) usage(); /* * Gross hack, but it makes it unnecessary to add an extra argument * to disable logging, and makes the code more efficient because it * doesn't actually write data to /dev/null. */ if (!strcmp(*argv, "/dev/null")) { logfile = display_file = NULL; } else { logfile = fopen(*argv, "a"); display_file = logfile; if (!logfile) { perror(*argv); exit(1); } } } else { break; } argc--; argv++; } if (argc != 1) usage(); if ((*argv)[0] == '-') usage(); #ifdef _WIN32 if (max_threads < 1) { fprintf(stderr, "warning: there must be at least one thread\n"); max_threads = 1; } if (max_threads > 1 && do_inetd) { fprintf(stderr, "warning: one thread may be used in conjunction " "with inetd\n"); } init_handles(); #endif service_name = *argv; if (server_acquire_creds(service_name, &server_creds) < 0) return -1; if (do_inetd) { close(1); close(2); sign_server(0, server_creds, export); close(0); } else { int stmp; stmp = create_socket(port); if (stmp >= 0) { do { struct _work_plan * work = malloc(sizeof(struct _work_plan)); if (work == NULL) { fprintf(stderr, "fatal error: out of memory"); break; } /* Accept a TCP connection */ work->s = accept(stmp, NULL, 0); if (work->s < 0) { perror("accepting connection"); continue; } work->server_creds = server_creds; work->export = export; if (max_threads == 1) { worker_bee(work); } else { if (wait_and_increment_thread_counter()) { #ifdef _WIN32 uintptr_t handle = _beginthread(worker_bee, 0, work); if (handle == (uintptr_t)-1) { closesocket(work->s); free(work); } #else int err; pthread_t thr; err = pthread_create(&thr, 0, worker_bee, work); if (err) { perror("pthread_create"); closesocket(work->s); free(work); } (void)pthread_detach(thr); #endif } else { fprintf(stderr, "fatal error incrementing thread " "counter"); closesocket(work->s); free(work); break; } } } while (!once); closesocket(stmp); } } (void)gss_release_cred(&min_stat, &server_creds); #ifdef _WIN32 cleanup_handles(); #else if (max_threads > 1) { while (1) sleep(999999); } #endif return 0; }