1 /* A little hacked up program that makes a TCP/IP call and reads a script to
2 drive it, for testing Exim server code running as a daemon. It's got a bit
3 messy with the addition of support for either OpenSSL or GnuTLS. The code for
4 those was hacked out of Exim itself, then code for OpenSSL OCSP stapling was
5 ripped from the openssl ocsp and s_client utilities. */
7 /* ANSI C standard includes */
22 #include <sys/types.h>
24 #include <netinet/in_systm.h>
25 #include <netinet/in.h>
26 #include <netinet/ip.h>
29 #include <arpa/inet.h>
31 #include <sys/resource.h>
32 #include <sys/socket.h>
43 #define S_ADDR_TYPE u_long
46 typedef unsigned char uschar;
49 #define US (unsigned char *)
56 static int sigalrm_seen = 0;
59 /* TLS support can be optionally included, either for OpenSSL or GnuTLS. The
60 latter needs a whole pile of tables. */
63 # include <openssl/crypto.h>
64 # include <openssl/x509.h>
65 # include <openssl/pem.h>
66 # include <openssl/ssl.h>
67 # include <openssl/err.h>
68 # include <openssl/rand.h>
70 # if OPENSSL_VERSION_NUMBER < 0x0090806fL && !defined(DISABLE_OCSP) && !defined(OPENSSL_NO_TLSEXT)
71 # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile"
75 # include <openssl/ocsp.h>
82 # include <gnutls/gnutls.h>
83 # include <gnutls/x509.h>
84 # if GNUTLS_VERSION_NUMBER >= 0x030103
86 # include <gnutls/ocsp.h>
91 /* Local static variables for GNUTLS */
93 static gnutls_dh_params dh_params = NULL;
95 static gnutls_certificate_credentials_t x509_cred = NULL;
96 static gnutls_session tls_session = NULL;
98 static int ssl_session_timeout = 200;
100 /* Priorities for TLS algorithms to use. */
102 static const int protocol_priority[16] = { GNUTLS_TLS1, GNUTLS_SSL3, 0 };
104 static const int kx_priority[16] = {
110 static int default_cipher_priority[16] = {
111 GNUTLS_CIPHER_AES_256_CBC,
112 GNUTLS_CIPHER_AES_128_CBC,
113 GNUTLS_CIPHER_3DES_CBC,
114 GNUTLS_CIPHER_ARCFOUR_128,
117 static const int mac_priority[16] = {
122 static const int comp_priority[16] = { GNUTLS_COMP_NULL, 0 };
123 static const int cert_type_priority[16] = { GNUTLS_CRT_X509, 0 };
125 #endif /*HAVE_GNUTLS*/
130 char * ocsp_stapling = NULL;
134 /*************************************************
135 * SIGALRM handler - crash out *
136 *************************************************/
139 sigalrm_handler_crash(int sig)
141 sig = sig; /* Keep picky compilers happy */
142 printf("\nClient timed out\n");
147 /*************************************************
148 * SIGALRM handler - set flag *
149 *************************************************/
152 sigalrm_handler_flag(int sig)
154 sig = sig; /* Keep picky compilers happy */
160 /****************************************************************************/
161 /****************************************************************************/
166 setup_verify(BIO *bp, char *CAfile, char *CApath)
170 if(!(store = X509_STORE_new())) goto end;
171 lookup=X509_STORE_add_lookup(store,X509_LOOKUP_file());
172 if (lookup == NULL) goto end;
174 if(!X509_LOOKUP_load_file(lookup,CAfile,X509_FILETYPE_PEM)) {
175 BIO_printf(bp, "Error loading file %s\n", CAfile);
178 } else X509_LOOKUP_load_file(lookup,NULL,X509_FILETYPE_DEFAULT);
180 lookup=X509_STORE_add_lookup(store,X509_LOOKUP_hash_dir());
181 if (lookup == NULL) goto end;
183 if(!X509_LOOKUP_add_dir(lookup,CApath,X509_FILETYPE_PEM)) {
184 BIO_printf(bp, "Error loading directory %s\n", CApath);
187 } else X509_LOOKUP_add_dir(lookup,NULL,X509_FILETYPE_DEFAULT);
192 X509_STORE_free(store);
199 tls_client_stapling_cb(SSL *s, void *arg)
201 const unsigned char *p;
206 X509_STORE *store = NULL;
209 len = SSL_get_tlsext_status_ocsp_resp(s, &p);
210 /*BIO_printf(arg, "OCSP response: ");*/
213 BIO_printf(arg, "no response received\n");
216 if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
218 BIO_printf(arg, "response parse error\n");
219 BIO_dump_indent(arg, (char *)p, len, 4);
222 if(!(bs = OCSP_response_get1_basic(rsp)))
224 BIO_printf(arg, "error parsing response\n");
228 CAfile = ocsp_stapling;
229 if(!(store = setup_verify(arg, CAfile, NULL)))
231 BIO_printf(arg, "error in cert setup\n");
235 /* No file of alternate certs, no options */
236 if(OCSP_basic_verify(bs, NULL, store, 0) <= 0)
238 BIO_printf(arg, "Response Verify Failure\n");
239 ERR_print_errors(arg);
243 BIO_printf(arg, "Response verify OK\n");
245 X509_STORE_free(store);
251 /*************************************************
252 * Start an OpenSSL TLS session *
253 *************************************************/
256 tls_start(int sock, SSL **ssl, SSL_CTX *ctx)
259 static const unsigned char *sid_ctx = US"exim";
261 RAND_load_file("client.c", -1); /* Not *very* random! */
263 *ssl = SSL_new (ctx);
264 SSL_set_session_id_context(*ssl, sid_ctx, strlen(CS sid_ctx));
265 SSL_set_fd (*ssl, sock);
266 SSL_set_connect_state(*ssl);
271 SSL_CTX_set_tlsext_status_cb(ctx, tls_client_stapling_cb);
272 SSL_CTX_set_tlsext_status_arg(ctx, BIO_new_fp(stdout, BIO_NOCLOSE));
273 SSL_set_tlsext_status_type(*ssl, TLSEXT_STATUSTYPE_ocsp);
277 signal(SIGALRM, sigalrm_handler_flag);
280 rc = SSL_connect (*ssl);
285 printf("SSL_connect timed out\n");
291 ERR_print_errors_fp(stdout);
295 printf("SSL connection using %s\n", SSL_get_cipher (*ssl));
300 /*************************************************
301 * SSL Information callback *
302 *************************************************/
305 info_callback(SSL *s, int where, int ret)
309 printf("SSL info: %s\n", SSL_state_string_long(s));
314 /****************************************************************************/
315 /****************************************************************************/
319 /*************************************************
320 * Handle GnuTLS error *
321 *************************************************/
323 /* Called from lots of places when errors occur before actually starting to do
324 the TLS handshake, that is, while the session is still in clear.
328 err a GnuTLS error number, or 0 if local error
330 Returns: doesn't - it dies
334 gnutls_error(uschar *prefix, int err)
336 fprintf(stderr, "GnuTLS connection error: %s:", prefix);
337 if (err != 0) fprintf(stderr, " %s", gnutls_strerror(err));
338 fprintf(stderr, "\n");
344 /*************************************************
345 * Setup up DH parameters *
346 *************************************************/
348 /* For the test suite, the parameters should always be available in the spool
357 uschar filename[200];
360 /* Initialize the data structures for holding the parameters */
362 ret = gnutls_dh_params_init(&dh_params);
363 if (ret < 0) gnutls_error(US"init dh_params", ret);
365 /* Open the cache file for reading and if successful, read it and set up the
368 fd = open("aux-fixed/gnutls-params", O_RDONLY, 0);
371 fprintf(stderr, "Failed to open spool/gnutls-params: %s\n", strerror(errno));
375 if (fstat(fd, &statbuf) < 0)
378 return gnutls_error(US"TLS cache stat failed", 0);
381 m.size = statbuf.st_size;
382 m.data = malloc(m.size);
384 return gnutls_error(US"memory allocation failed", 0);
385 if (read(fd, m.data, m.size) != m.size)
386 return gnutls_error(US"TLS cache read failed", 0);
389 ret = gnutls_dh_params_import_pkcs3(dh_params, &m, GNUTLS_X509_FMT_PEM);
390 if (ret < 0) return gnutls_error(US"DH params import", ret);
397 /*************************************************
398 * Initialize for GnuTLS *
399 *************************************************/
403 certificate certificate file
404 privatekey private key file
408 tls_init(uschar *certificate, uschar *privatekey)
412 rc = gnutls_global_init();
413 if (rc < 0) gnutls_error(US"gnutls_global_init", rc);
415 /* Read D-H parameters from the cache file. */
419 /* Create the credentials structure */
421 rc = gnutls_certificate_allocate_credentials(&x509_cred);
422 if (rc < 0) gnutls_error(US"certificate_allocate_credentials", rc);
424 /* Set the certificate and private keys */
426 if (certificate != NULL)
428 rc = gnutls_certificate_set_x509_key_file(x509_cred, CS certificate,
429 CS privatekey, GNUTLS_X509_FMT_PEM);
430 if (rc < 0) gnutls_error("gnutls_certificate", rc);
433 /* Associate the parameters with the x509 credentials structure. */
435 gnutls_certificate_set_dh_params(x509_cred, dh_params);
437 /* set the CA info for server-cert verify */
439 gnutls_certificate_set_x509_trust_file(x509_cred, ocsp_stapling,
440 GNUTLS_X509_FMT_PEM);
445 /*************************************************
446 * Initialize a single GNUTLS session *
447 *************************************************/
449 static gnutls_session
450 tls_session_init(void)
452 gnutls_session session;
454 gnutls_init(&session, GNUTLS_CLIENT);
456 gnutls_cipher_set_priority(session, default_cipher_priority);
457 gnutls_compression_set_priority(session, comp_priority);
458 gnutls_kx_set_priority(session, kx_priority);
459 gnutls_protocol_set_priority(session, protocol_priority);
460 gnutls_mac_set_priority(session, mac_priority);
462 gnutls_cred_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);
464 gnutls_dh_set_prime_bits(session, DH_BITS);
465 gnutls_db_set_cache_expiration(session, ssl_session_timeout);
472 /****************************************************************************/
473 /****************************************************************************/
478 /*************************************************
480 *************************************************/
482 const char * const HELP_MESSAGE = "\n\
486 [<outgoing interface>]\n\
491 int main(int argc, char **argv)
493 struct sockaddr *s_ptr;
494 struct sockaddr_in s_in4;
495 char *interface = NULL;
496 char *address = NULL;
497 char *certfile = NULL;
498 char *keyfile = NULL;
501 int host_af, port, s_len, rc, sock, save_errno;
504 int sent_starttls = 0;
505 int tls_on_connect = 0;
509 struct sockaddr_in6 s_in6;
517 unsigned char outbuffer[10240];
518 unsigned char inbuffer[10240];
519 unsigned char *inptr = inbuffer;
521 *inptr = 0; /* Buffer empty */
525 while (argc >= argi + 1 && argv[argi][0] == '-')
527 if (strcmp(argv[argi], "-help") == 0 ||
528 strcmp(argv[argi], "--help") == 0 ||
529 strcmp(argv[argi], "-h") == 0)
534 if (strcmp(argv[argi], "-tls-on-connect") == 0)
540 else if (strcmp(argv[argi], "-ocsp") == 0)
542 if (argc < ++argi + 1)
544 fprintf(stderr, "Missing required certificate file for ocsp option\n");
547 ocsp_stapling = argv[argi++];
551 else if (argv[argi][1] == 't' && isdigit(argv[argi][2]))
553 tmplong = strtol(argv[argi]+2, &end, 10);
554 if (end == argv[argi]+2 || *end)
556 fprintf(stderr, "Failed to parse seconds from option <%s>\n",
560 if (tmplong > 10000L)
562 fprintf(stderr, "Unreasonably long wait of %ld seconds requested\n",
568 fprintf(stderr, "Timeout must not be negative (%ld)\n", tmplong);
571 timeout = (int) tmplong;
576 fprintf(stderr, "Unrecognized option %s\n", argv[argi]);
581 /* Mandatory 1st arg is IP address */
585 fprintf(stderr, "No IP address given\n");
589 address = argv[argi++];
590 host_af = (strchr(address, ':') != NULL)? AF_INET6 : AF_INET;
592 /* Mandatory 2nd arg is port */
596 fprintf(stderr, "No port number given\n");
600 port = atoi(argv[argi++]);
602 /* Optional next arg is interface */
605 (isdigit((unsigned char)argv[argi][0]) || argv[argi][0] == ':'))
606 interface = argv[argi++];
608 /* Any more arguments are the name of a certificate file and key file */
610 if (argc > argi) certfile = argv[argi++];
611 if (argc > argi) keyfile = argv[argi++];
615 /* For an IPv6 address, use an IPv6 sockaddr structure. */
617 if (host_af == AF_INET6)
619 s_ptr = (struct sockaddr *)&s_in6;
620 s_len = sizeof(s_in6);
625 /* For an IPv4 address, use an IPv4 sockaddr structure,
626 even on an IPv6 system. */
629 s_ptr = (struct sockaddr *)&s_in4;
630 s_len = sizeof(s_in4);
633 printf("Connecting to %s port %d ... ", address, port);
635 sock = socket(host_af, SOCK_STREAM, 0);
638 printf("socket creation failed: %s\n", strerror(errno));
642 /* Bind to a specific interface if requested. On an IPv6 system, this has
643 to be of the same family as the address we are calling. On an IPv4 system the
644 test is redundant, but it keeps the code tidier. */
646 if (interface != NULL)
648 int interface_af = (strchr(interface, ':') != NULL)? AF_INET6 : AF_INET;
650 if (interface_af == host_af)
654 /* Set up for IPv6 binding */
656 if (host_af == AF_INET6)
658 memset(&s_in6, 0, sizeof(s_in6));
659 s_in6.sin6_family = AF_INET6;
661 if (inet_pton(AF_INET6, interface, &s_in6.sin6_addr) != 1)
663 printf("Unable to parse \"%s\"", interface);
670 /* Set up for IPv4 binding */
673 memset(&s_in4, 0, sizeof(s_in4));
674 s_in4.sin_family = AF_INET;
676 s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(interface);
681 if (bind(sock, s_ptr, s_len) < 0)
683 printf("Unable to bind outgoing SMTP call to %s: %s",
684 interface, strerror(errno));
690 /* Set up a remote IPv6 address */
693 if (host_af == AF_INET6)
695 memset(&s_in6, 0, sizeof(s_in6));
696 s_in6.sin6_family = AF_INET6;
697 s_in6.sin6_port = htons(port);
698 if (inet_pton(host_af, address, &s_in6.sin6_addr) != 1)
700 printf("Unable to parse \"%s\"", address);
707 /* Set up a remote IPv4 address */
710 memset(&s_in4, 0, sizeof(s_in4));
711 s_in4.sin_family = AF_INET;
712 s_in4.sin_port = htons(port);
713 s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(address);
716 /* SIGALRM handler crashes out */
718 signal(SIGALRM, sigalrm_handler_crash);
720 rc = connect(sock, s_ptr, s_len);
724 /* A failure whose error code is "Interrupted system call" is in fact
725 an externally applied timeout if the signal handler has been run. */
730 printf("connect failed: %s\n", strerror(save_errno));
734 printf("connected\n");
737 /* --------------- Set up for OpenSSL --------------- */
741 SSL_load_error_strings();
743 ctx = SSL_CTX_new(SSLv23_method());
746 printf ("SSL_CTX_new failed\n");
750 if (certfile != NULL)
752 if (!SSL_CTX_use_certificate_file(ctx, certfile, SSL_FILETYPE_PEM))
754 printf("SSL_CTX_use_certificate_file failed\n");
757 printf("Certificate file = %s\n", certfile);
762 if (!SSL_CTX_use_PrivateKey_file(ctx, keyfile, SSL_FILETYPE_PEM))
764 printf("SSL_CTX_use_PrivateKey_file failed\n");
767 printf("Key file = %s\n", keyfile);
770 SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_BOTH);
771 SSL_CTX_set_timeout(ctx, 200);
772 SSL_CTX_set_info_callback(ctx, (void (*)())info_callback);
776 /* --------------- Set up for GnuTLS --------------- */
779 if (certfile != NULL) printf("Certificate file = %s\n", certfile);
780 if (keyfile != NULL) printf("Key file = %s\n", keyfile);
781 tls_init(certfile, keyfile);
782 tls_session = tls_session_init();
785 gnutls_ocsp_status_request_enable_client(tls_session, NULL, 0, NULL);
787 gnutls_transport_set_ptr(tls_session, (gnutls_transport_ptr)sock);
789 /* When the server asks for a certificate and the client does not have one,
790 there is a SIGPIPE error in the gnutls_handshake() function for some reason
791 that is not understood. As luck would have it, this has never hit Exim itself
792 because it ignores SIGPIPE errors. Doing the same here allows it all to work as
795 signal(SIGPIPE, SIG_IGN);
798 /* ---------------------------------------------- */
801 /* Start TLS session if configured to do so without STARTTLS */
806 printf("Attempting to start TLS\n");
809 tls_active = tls_start(sock, &ssl, ctx);
813 sigalrm_seen = FALSE;
815 tls_active = gnutls_handshake(tls_session) >= 0;
820 printf("Failed to start TLS\n");
821 #if defined(HAVE_GNUTLS) && defined(HAVE_OCSP)
822 else if ( ocsp_stapling
823 && gnutls_ocsp_status_request_is_checked(tls_session, 0) == 0)
824 printf("Failed to verify certificate status\n");
827 printf("Succeeded in starting TLS\n");
831 while (fgets(CS outbuffer, sizeof(outbuffer), stdin) != NULL)
833 int n = (int)strlen(CS outbuffer);
834 while (n > 0 && isspace(outbuffer[n-1])) n--;
837 /* Expect incoming */
839 if (strncmp(CS outbuffer, "??? ", 4) == 0)
841 unsigned char *lineptr;
842 printf("%s\n", outbuffer);
844 if (*inptr == 0) /* Refill input buffer */
849 rc = SSL_read (ssl, inbuffer, sizeof(inbuffer) - 1);
852 rc = gnutls_record_recv(tls_session, CS inbuffer, sizeof(inbuffer) - 1);
858 rc = read(sock, inbuffer, sizeof(inbuffer));
864 printf("Read error %s\n", strerror(errno));
869 printf("Unexpected EOF read\n");
881 while (*inptr != 0 && *inptr != '\r' && *inptr != '\n') inptr++;
885 if (*inptr == '\n') inptr++;
888 printf("<<< %s\n", lineptr);
889 if (strncmp(CS lineptr, CS outbuffer + 4, (int)strlen(CS outbuffer) - 4) != 0)
891 printf("\n******** Input mismatch ********\n");
898 if (lineptr[0] == '2')
903 printf("Attempting to start TLS\n");
907 tls_active = tls_start(sock, &ssl, ctx);
911 sigalrm_seen = FALSE;
913 tls_active = gnutls_handshake(tls_session) >= 0;
919 printf("Failed to start TLS\n");
923 else if (ocsp_stapling)
925 if ((rc= gnutls_certificate_verify_peers2(tls_session, &verify)) < 0)
927 printf("Failed to verify certificate: %s\n", gnutls_strerror(rc));
930 else if (verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED))
932 printf("Bad certificate\n");
936 else if (gnutls_ocsp_status_request_is_checked(tls_session, 0) == 0)
938 printf("Failed to verify certificate status\n");
940 gnutls_datum_t stapling;
941 gnutls_ocsp_resp_t resp;
942 gnutls_datum_t printed;
943 if ( (rc= gnutls_ocsp_status_request_get(tls_session, &stapling)) == 0
944 && (rc= gnutls_ocsp_resp_init(&resp)) == 0
945 && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0
946 && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_FULL, &printed)) == 0
949 fprintf(stderr, "%.4096s", printed.data);
950 gnutls_free(printed.data);
953 (void) fprintf(stderr,"ocsp decode: %s", gnutls_strerror(rc));
961 printf("Succeeded in starting TLS\n");
963 else printf("Abandoning TLS start attempt\n");
969 /* Wait for a bit before proceeding */
971 else if (strncmp(CS outbuffer, "+++ ", 4) == 0)
973 printf("%s\n", outbuffer);
974 sleep(atoi(CS outbuffer + 4));
977 /* Send outgoing, but barf if unconsumed incoming */
981 unsigned char *escape;
985 printf("Unconsumed input: %s", inptr);
986 printf(" About to send: %s\n", outbuffer);
994 if (strcmp(CS outbuffer, "stoptls") == 0 ||
995 strcmp(CS outbuffer, "STOPTLS") == 0)
999 printf("STOPTLS read when TLS not active\n");
1002 printf("Shutting down TLS encryption\n");
1010 gnutls_bye(tls_session, GNUTLS_SHUT_WR);
1011 gnutls_deinit(tls_session);
1013 gnutls_global_deinit();
1020 /* Remember that we sent STARTTLS */
1022 sent_starttls = (strcmp(CS outbuffer, "starttls") == 0 ||
1023 strcmp(CS outbuffer, "STARTTLS") == 0);
1025 /* Fudge: if the command is "starttls_wait", we send the starttls bit,
1026 but we haven't set the flag, so that there is no negotiation. This is for
1027 testing the server's timeout. */
1029 if (strcmp(CS outbuffer, "starttls_wait") == 0)
1036 printf(">>> %s\n", outbuffer);
1037 strcpy(CS outbuffer + n, "\r\n");
1039 /* Turn "\n" and "\r" into the relevant characters. This is a hack. */
1041 while ((escape = US strstr(CS outbuffer, "\\r")) != NULL)
1044 memmove(escape + 1, escape + 2, (n + 2) - (escape - outbuffer) - 2);
1048 while ((escape = US strstr(CS outbuffer, "\\n")) != NULL)
1051 memmove(escape + 1, escape + 2, (n + 2) - (escape - outbuffer) - 2);
1061 rc = SSL_write (ssl, outbuffer, n + 2);
1064 rc = gnutls_record_send(tls_session, CS outbuffer, n + 2);
1067 printf("GnuTLS write error: %s\n", gnutls_strerror(rc));
1074 rc = write(sock, outbuffer, n + 2);
1080 printf("Write error: %s\n", strerror(errno));
1086 printf("End of script\n");
1092 /* End of client.c */