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>
27 #include <netinet/tcp.h>
30 #include <arpa/inet.h>
32 #include <sys/resource.h>
33 #include <sys/socket.h>
44 #define S_ADDR_TYPE u_long
47 typedef unsigned char uschar;
50 #define US (unsigned char *)
57 static int sigalrm_seen = 0;
60 /* TLS support can be optionally included, either for OpenSSL or GnuTLS. The
61 latter needs a whole pile of tables. */
64 # include <openssl/crypto.h>
65 # include <openssl/x509.h>
66 # include <openssl/pem.h>
67 # include <openssl/ssl.h>
68 # include <openssl/err.h>
69 # include <openssl/rand.h>
71 # if OPENSSL_VERSION_NUMBER < 0x0090806fL && !defined(DISABLE_OCSP) && !defined(OPENSSL_NO_TLSEXT)
72 # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile"
76 # include <openssl/ocsp.h>
83 # include <gnutls/gnutls.h>
84 # include <gnutls/x509.h>
85 # if GNUTLS_VERSION_NUMBER >= 0x030103
87 # include <gnutls/ocsp.h>
89 # ifndef GNUTLS_NO_EXTENSIONS
90 # define GNUTLS_NO_EXTENSIONS 0
95 /* Local static variables for GNUTLS */
97 static gnutls_dh_params_t dh_params = NULL;
99 static gnutls_certificate_credentials_t x509_cred = NULL;
100 static gnutls_session_t tls_session = NULL;
102 static int ssl_session_timeout = 200;
104 /* Priorities for TLS algorithms to use. */
106 #if GNUTLS_VERSION_NUMBER < 0x030400
107 static const int protocol_priority[16] = { GNUTLS_TLS1, GNUTLS_SSL3, 0 };
109 static const int kx_priority[16] = {
115 static int default_cipher_priority[16] = {
116 GNUTLS_CIPHER_AES_256_CBC,
117 GNUTLS_CIPHER_AES_128_CBC,
118 GNUTLS_CIPHER_3DES_CBC,
119 GNUTLS_CIPHER_ARCFOUR_128,
122 static const int mac_priority[16] = {
127 static const int comp_priority[16] = { GNUTLS_COMP_NULL, 0 };
130 #endif /*HAVE_GNUTLS*/
135 char * ocsp_stapling = NULL;
139 /*************************************************
140 * SIGALRM handler - crash out *
141 *************************************************/
144 sigalrm_handler_crash(int sig)
146 sig = sig; /* Keep picky compilers happy */
147 printf("\nClient timed out\n");
152 /*************************************************
153 * SIGALRM handler - set flag *
154 *************************************************/
157 sigalrm_handler_flag(int sig)
159 sig = sig; /* Keep picky compilers happy */
165 /****************************************************************************/
166 /****************************************************************************/
169 # ifndef DISABLE_OCSP
171 static STACK_OF(X509) *
172 chain_from_pem_file(const uschar * file)
178 if (!(sk = sk_X509_new_null())) return NULL;
179 if (!(bp = BIO_new_file(CS file, "r"))) return NULL;
180 while ((x = PEM_read_bio_X509(bp, NULL, 0, NULL)))
189 cert_stack_free(STACK_OF(X509) * sk)
191 while (sk_X509_num(sk) > 0) (void) sk_X509_pop(sk);
197 tls_client_stapling_cb(SSL *s, void *arg)
199 const unsigned char *p;
206 len = SSL_get_tlsext_status_ocsp_resp(s, &p);
207 /*BIO_printf(arg, "OCSP response: ");*/
210 BIO_printf(arg, "no response received\n");
213 if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
215 BIO_printf(arg, "response parse error\n");
216 BIO_dump_indent(arg, (char *)p, len, 4);
219 if(!(bs = OCSP_response_get1_basic(rsp)))
221 BIO_printf(arg, "error parsing response\n");
226 if (!(sk = chain_from_pem_file(ocsp_stapling)))
228 BIO_printf(arg, "error in cert setup\n");
232 /* OCSP_basic_verify takes a "store" arg, but does not
233 use it for the chain verification, which is all we do
234 when OCSP_NOVERIFY is set. The content from the wire
235 (in "bs") and a cert-stack "sk" are all that is used. */
237 if(OCSP_basic_verify(bs, sk, NULL, OCSP_NOVERIFY) <= 0)
239 BIO_printf(arg, "Response Verify Failure\n");
240 ERR_print_errors(arg);
244 BIO_printf(arg, "Response verify OK\n");
249 # endif /*DISABLE_OCSP*/
252 /*************************************************
253 * Start an OpenSSL TLS session *
254 *************************************************/
257 tls_start(int sock, SSL **ssl, SSL_CTX *ctx)
260 static const unsigned char *sid_ctx = US"exim";
262 RAND_load_file("client.c", -1); /* Not *very* random! */
264 *ssl = SSL_new (ctx);
265 SSL_set_session_id_context(*ssl, sid_ctx, strlen(CS sid_ctx));
266 SSL_set_fd (*ssl, sock);
267 SSL_set_connect_state(*ssl);
272 SSL_CTX_set_tlsext_status_cb(ctx, tls_client_stapling_cb);
273 SSL_CTX_set_tlsext_status_arg(ctx, BIO_new_fp(stdout, BIO_NOCLOSE));
274 SSL_set_tlsext_status_type(*ssl, TLSEXT_STATUSTYPE_ocsp);
278 signal(SIGALRM, sigalrm_handler_flag);
281 rc = SSL_connect (*ssl);
286 printf("SSL_connect timed out\n");
292 ERR_print_errors_fp(stdout);
296 printf("SSL connection using %s\n", SSL_get_cipher (*ssl));
301 /*************************************************
302 * SSL Information callback *
303 *************************************************/
306 info_callback(SSL *s, int where, int ret)
310 printf("SSL info: %s\n", SSL_state_string_long(s));
315 /****************************************************************************/
316 /****************************************************************************/
320 /*************************************************
321 * Handle GnuTLS error *
322 *************************************************/
324 /* Called from lots of places when errors occur before actually starting to do
325 the TLS handshake, that is, while the session is still in clear.
329 err a GnuTLS error number, or 0 if local error
331 Returns: doesn't - it dies
335 gnutls_error(uschar *prefix, int err)
337 fprintf(stderr, "GnuTLS connection error: %s:", prefix);
338 if (err != 0) fprintf(stderr, " %s", gnutls_strerror(err));
339 fprintf(stderr, "\n");
345 /*************************************************
346 * Setup up DH parameters *
347 *************************************************/
349 /* For the test suite, the parameters should always be available in the spool
358 uschar filename[200];
361 /* Initialize the data structures for holding the parameters */
363 ret = gnutls_dh_params_init(&dh_params);
364 if (ret < 0) gnutls_error(US"init dh_params", ret);
366 /* Open the cache file for reading and if successful, read it and set up the
369 fd = open("aux-fixed/gnutls-params", O_RDONLY, 0);
372 fprintf(stderr, "Failed to open spool/gnutls-params: %s\n", strerror(errno));
376 if (fstat(fd, &statbuf) < 0)
379 return gnutls_error(US"TLS cache stat failed", 0);
382 m.size = statbuf.st_size;
383 m.data = malloc(m.size);
385 return gnutls_error(US"memory allocation failed", 0);
386 if (read(fd, m.data, m.size) != m.size)
387 return gnutls_error(US"TLS cache read failed", 0);
390 ret = gnutls_dh_params_import_pkcs3(dh_params, &m, GNUTLS_X509_FMT_PEM);
391 if (ret < 0) return gnutls_error(US"DH params import", ret);
398 /*************************************************
399 * Initialize for GnuTLS *
400 *************************************************/
404 certificate certificate file
405 privatekey private key file
409 tls_init(uschar *certificate, uschar *privatekey)
413 rc = gnutls_global_init();
414 if (rc < 0) gnutls_error(US"gnutls_global_init", rc);
416 /* Read D-H parameters from the cache file. */
420 /* Create the credentials structure */
422 rc = gnutls_certificate_allocate_credentials(&x509_cred);
423 if (rc < 0) gnutls_error(US"certificate_allocate_credentials", rc);
425 /* Set the certificate and private keys */
427 if (certificate != NULL)
429 rc = gnutls_certificate_set_x509_key_file(x509_cred, CS certificate,
430 CS privatekey, GNUTLS_X509_FMT_PEM);
431 if (rc < 0) gnutls_error("gnutls_certificate", rc);
434 /* Associate the parameters with the x509 credentials structure. */
436 gnutls_certificate_set_dh_params(x509_cred, dh_params);
438 /* set the CA info for server-cert verify */
440 gnutls_certificate_set_x509_trust_file(x509_cred, ocsp_stapling,
441 GNUTLS_X509_FMT_PEM);
446 /*************************************************
447 * Initialize a single GNUTLS session *
448 *************************************************/
450 static gnutls_session_t
451 tls_session_init(void)
453 gnutls_session_t session;
455 gnutls_init(&session, GNUTLS_CLIENT | GNUTLS_NO_EXTENSIONS);
457 #if GNUTLS_VERSION_NUMBER < 0x030400
458 gnutls_cipher_set_priority(session, default_cipher_priority);
459 gnutls_compression_set_priority(session, comp_priority);
460 gnutls_kx_set_priority(session, kx_priority);
461 gnutls_protocol_set_priority(session, protocol_priority);
462 gnutls_mac_set_priority(session, mac_priority);
464 gnutls_cred_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);
466 gnutls_set_default_priority(session);
467 gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, x509_cred);
470 gnutls_dh_set_prime_bits(session, DH_BITS);
471 gnutls_db_set_cache_expiration(session, ssl_session_timeout);
478 /****************************************************************************/
479 /****************************************************************************/
484 /*************************************************
486 *************************************************/
488 const char * const HELP_MESSAGE = "\n\
496 [-tn] n seconds timeout\n\
499 [<outgoing interface>]\n\
504 int main(int argc, char **argv)
506 struct sockaddr *s_ptr;
507 struct sockaddr_in s_in4;
508 char *interface = NULL;
509 char *address = NULL;
510 char *certfile = NULL;
511 char *keyfile = NULL;
514 int host_af, port, s_len, rc, sock, save_errno;
517 int sent_starttls = 0;
518 int tls_on_connect = 0;
522 struct sockaddr_in6 s_in6;
530 unsigned char outbuffer[10240];
531 unsigned char inbuffer[10240];
532 unsigned char *inptr = inbuffer;
534 *inptr = 0; /* Buffer empty */
538 while (argc >= argi + 1 && argv[argi][0] == '-')
540 if (strcmp(argv[argi], "-help") == 0 ||
541 strcmp(argv[argi], "--help") == 0 ||
542 strcmp(argv[argi], "-h") == 0)
547 if (strcmp(argv[argi], "-tls-on-connect") == 0)
553 else if (strcmp(argv[argi], "-ocsp") == 0)
555 if (argc < ++argi + 1)
557 fprintf(stderr, "Missing required certificate file for ocsp option\n");
560 ocsp_stapling = argv[argi++];
564 else if (argv[argi][1] == 't' && isdigit(argv[argi][2]))
566 tmplong = strtol(argv[argi]+2, &end, 10);
567 if (end == argv[argi]+2 || *end)
569 fprintf(stderr, "Failed to parse seconds from option <%s>\n",
573 if (tmplong > 10000L)
575 fprintf(stderr, "Unreasonably long wait of %ld seconds requested\n",
581 fprintf(stderr, "Timeout must not be negative (%ld)\n", tmplong);
584 timeout = (int) tmplong;
589 fprintf(stderr, "Unrecognized option %s\n", argv[argi]);
594 /* Mandatory 1st arg is IP address */
598 fprintf(stderr, "No IP address given\n");
602 address = argv[argi++];
603 host_af = (strchr(address, ':') != NULL)? AF_INET6 : AF_INET;
605 /* Mandatory 2nd arg is port */
609 fprintf(stderr, "No port number given\n");
613 port = atoi(argv[argi++]);
615 /* Optional next arg is interface */
618 (isdigit((unsigned char)argv[argi][0]) || argv[argi][0] == ':'))
619 interface = argv[argi++];
621 /* Any more arguments are the name of a certificate file and key file */
623 if (argc > argi) certfile = argv[argi++];
624 if (argc > argi) keyfile = argv[argi++];
628 /* For an IPv6 address, use an IPv6 sockaddr structure. */
630 if (host_af == AF_INET6)
632 s_ptr = (struct sockaddr *)&s_in6;
633 s_len = sizeof(s_in6);
638 /* For an IPv4 address, use an IPv4 sockaddr structure,
639 even on an IPv6 system. */
642 s_ptr = (struct sockaddr *)&s_in4;
643 s_len = sizeof(s_in4);
646 printf("Connecting to %s port %d ... ", address, port);
648 sock = socket(host_af, SOCK_STREAM, 0);
651 printf("socket creation failed: %s\n", strerror(errno));
655 /* Bind to a specific interface if requested. On an IPv6 system, this has
656 to be of the same family as the address we are calling. On an IPv4 system the
657 test is redundant, but it keeps the code tidier. */
659 if (interface != NULL)
661 int interface_af = (strchr(interface, ':') != NULL)? AF_INET6 : AF_INET;
663 if (interface_af == host_af)
667 /* Set up for IPv6 binding */
669 if (host_af == AF_INET6)
671 memset(&s_in6, 0, sizeof(s_in6));
672 s_in6.sin6_family = AF_INET6;
674 if (inet_pton(AF_INET6, interface, &s_in6.sin6_addr) != 1)
676 printf("Unable to parse \"%s\"", interface);
683 /* Set up for IPv4 binding */
686 memset(&s_in4, 0, sizeof(s_in4));
687 s_in4.sin_family = AF_INET;
689 s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(interface);
694 if (bind(sock, s_ptr, s_len) < 0)
696 printf("Unable to bind outgoing SMTP call to %s: %s",
697 interface, strerror(errno));
703 /* Set up a remote IPv6 address */
706 if (host_af == AF_INET6)
708 memset(&s_in6, 0, sizeof(s_in6));
709 s_in6.sin6_family = AF_INET6;
710 s_in6.sin6_port = htons(port);
711 if (inet_pton(host_af, address, &s_in6.sin6_addr) != 1)
713 printf("Unable to parse \"%s\"", address);
720 /* Set up a remote IPv4 address */
723 memset(&s_in4, 0, sizeof(s_in4));
724 s_in4.sin_family = AF_INET;
725 s_in4.sin_port = htons(port);
726 s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(address);
729 /* SIGALRM handler crashes out */
731 signal(SIGALRM, sigalrm_handler_crash);
733 rc = connect(sock, s_ptr, s_len);
737 /* A failure whose error code is "Interrupted system call" is in fact
738 an externally applied timeout if the signal handler has been run. */
743 printf("connect failed: %s\n", strerror(save_errno));
747 printf("connected\n");
750 /* --------------- Set up for OpenSSL --------------- */
754 SSL_load_error_strings();
756 ctx = SSL_CTX_new(SSLv23_method());
759 printf ("SSL_CTX_new failed\n");
763 if (certfile != NULL)
765 if (!SSL_CTX_use_certificate_file(ctx, certfile, SSL_FILETYPE_PEM))
767 printf("SSL_CTX_use_certificate_file failed\n");
770 printf("Certificate file = %s\n", certfile);
775 if (!SSL_CTX_use_PrivateKey_file(ctx, keyfile, SSL_FILETYPE_PEM))
777 printf("SSL_CTX_use_PrivateKey_file failed\n");
780 printf("Key file = %s\n", keyfile);
783 SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_BOTH);
784 SSL_CTX_set_timeout(ctx, 200);
785 SSL_CTX_set_info_callback(ctx, (void (*)())info_callback);
789 /* --------------- Set up for GnuTLS --------------- */
792 if (certfile != NULL) printf("Certificate file = %s\n", certfile);
793 if (keyfile != NULL) printf("Key file = %s\n", keyfile);
794 tls_init(certfile, keyfile);
795 tls_session = tls_session_init();
798 gnutls_ocsp_status_request_enable_client(tls_session, NULL, 0, NULL);
800 gnutls_transport_set_ptr(tls_session, (gnutls_transport_ptr_t)(intptr_t)sock);
802 /* When the server asks for a certificate and the client does not have one,
803 there is a SIGPIPE error in the gnutls_handshake() function for some reason
804 that is not understood. As luck would have it, this has never hit Exim itself
805 because it ignores SIGPIPE errors. Doing the same here allows it all to work as
808 signal(SIGPIPE, SIG_IGN);
811 /* ---------------------------------------------- */
814 /* Start TLS session if configured to do so without STARTTLS */
819 printf("Attempting to start TLS\n");
822 tls_active = tls_start(sock, &ssl, ctx);
828 sigalrm_seen = FALSE;
831 rc = gnutls_handshake(tls_session);
832 } while (rc < 0 && gnutls_error_is_fatal(rc) == 0);
833 tls_active = rc >= 0;
836 if (!tls_active) printf("%s\n", gnutls_strerror(rc));
841 printf("Failed to start TLS\n");
842 #if defined(HAVE_GNUTLS) && defined(HAVE_OCSP)
843 else if ( ocsp_stapling
844 && gnutls_ocsp_status_request_is_checked(tls_session, 0) == 0)
845 printf("Failed to verify certificate status\n");
848 printf("Succeeded in starting TLS\n");
852 while (fgets(CS outbuffer, sizeof(outbuffer), stdin) != NULL)
854 int n = (int)strlen(CS outbuffer);
856 /* Strip trailing newline */
857 if (outbuffer[n-1] == '\n') outbuffer[--n] = 0;
859 /* Expect incoming */
861 if ( strncmp(CS outbuffer, "???", 3) == 0
862 && (outbuffer[3] == ' ' || outbuffer[3] == '*')
865 unsigned char *lineptr;
866 unsigned exp_eof = outbuffer[3] == '*';
868 printf("%s\n", outbuffer);
870 if (*inptr == 0) /* Refill input buffer */
875 rc = SSL_read (ssl, inbuffer, sizeof(inbuffer) - 1);
878 rc = gnutls_record_recv(tls_session, CS inbuffer, sizeof(inbuffer) - 1);
884 rc = read(sock, inbuffer, sizeof(inbuffer));
890 printf("Read error %s\n", strerror(errno));
896 printf("Expected EOF read\n");
901 printf("Enexpected EOF read\n");
907 printf("Expected EOF not read\n");
919 while (*inptr != 0 && *inptr != '\r' && *inptr != '\n') inptr++;
923 if (*inptr == '\n') inptr++;
926 printf("<<< %s\n", lineptr);
927 if (strncmp(CS lineptr, CS outbuffer + 4, (int)strlen(CS outbuffer) - 4) != 0)
929 printf("\n******** Input mismatch ********\n");
936 if (lineptr[0] == '2')
941 printf("Attempting to start TLS\n");
945 tls_active = tls_start(sock, &ssl, ctx);
951 sigalrm_seen = FALSE;
954 rc = gnutls_handshake(tls_session);
955 } while (rc < 0 && gnutls_error_is_fatal(rc) == 0);
956 tls_active = rc >= 0;
959 if (!tls_active) printf("%s\n", gnutls_strerror(rc));
965 printf("Failed to start TLS\n");
969 else if (ocsp_stapling)
971 if ((rc= gnutls_certificate_verify_peers2(tls_session, &verify)) < 0)
973 printf("Failed to verify certificate: %s\n", gnutls_strerror(rc));
976 else if (verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED))
978 printf("Bad certificate\n");
982 else if (gnutls_ocsp_status_request_is_checked(tls_session, 0) == 0)
984 printf("Failed to verify certificate status\n");
986 gnutls_datum_t stapling;
987 gnutls_ocsp_resp_t resp;
988 gnutls_datum_t printed;
989 if ( (rc= gnutls_ocsp_status_request_get(tls_session, &stapling)) == 0
990 && (rc= gnutls_ocsp_resp_init(&resp)) == 0
991 && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0
992 && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_FULL, &printed)) == 0
995 fprintf(stderr, "%.4096s", printed.data);
996 gnutls_free(printed.data);
999 (void) fprintf(stderr,"ocsp decode: %s", gnutls_strerror(rc));
1007 printf("Succeeded in starting TLS\n");
1009 else printf("Abandoning TLS start attempt\n");
1015 /* Wait for a bit before proceeding */
1017 else if (strncmp(CS outbuffer, "+++ ", 4) == 0)
1019 printf("%s\n", outbuffer);
1020 sleep(atoi(CS outbuffer + 4));
1023 /* Send outgoing, but barf if unconsumed incoming */
1027 unsigned char *escape;
1031 printf("Unconsumed input: %s", inptr);
1032 printf(" About to send: %s\n", outbuffer);
1040 if (strcmp(CS outbuffer, "stoptls") == 0 ||
1041 strcmp(CS outbuffer, "STOPTLS") == 0)
1045 printf("STOPTLS read when TLS not active\n");
1048 printf("Shutting down TLS encryption\n");
1056 gnutls_bye(tls_session, GNUTLS_SHUT_WR);
1057 gnutls_deinit(tls_session);
1059 gnutls_global_deinit();
1066 /* Remember that we sent STARTTLS */
1068 sent_starttls = (strcmp(CS outbuffer, "starttls") == 0 ||
1069 strcmp(CS outbuffer, "STARTTLS") == 0);
1071 /* Fudge: if the command is "starttls_wait", we send the starttls bit,
1072 but we haven't set the flag, so that there is no negotiation. This is for
1073 testing the server's timeout. */
1075 if (strcmp(CS outbuffer, "starttls_wait") == 0)
1082 printf(">>> %s\n", outbuffer);
1083 strcpy(CS outbuffer + n, "\r\n");
1085 /* Turn "\n" and "\r" into the relevant characters. This is a hack. */
1087 while ((escape = US strstr(CS outbuffer, "\\r")) != NULL)
1090 memmove(escape + 1, escape + 2, (n + 2) - (escape - outbuffer) - 2);
1094 while ((escape = US strstr(CS outbuffer, "\\n")) != NULL)
1097 memmove(escape + 1, escape + 2, (n + 2) - (escape - outbuffer) - 2);
1107 rc = SSL_write (ssl, outbuffer, n + 2);
1110 rc = gnutls_record_send(tls_session, CS outbuffer, n + 2);
1113 printf("GnuTLS write error: %s\n", gnutls_strerror(rc));
1120 rc = write(sock, outbuffer, n + 2);
1126 printf("Write error: %s\n", strerror(errno));
1132 printf("End of script\n");
1133 shutdown(sock, SHUT_WR);
1134 while ((rc = read(sock, inbuffer, sizeof(inbuffer))) > 0) ;
1140 /* End of client.c */