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 /* Turn "\n" and "\r" into the relevant characters. This is a hack. */
482 unescape_buf(unsigned char * buf, int len)
488 for (s = buf; s < buf+len; s++) if (*s == '\\')
492 default: c = s[1]; shift = 1; break;
493 case 'n': c = '\n'; shift = 1; break;
494 case 'r': c = '\r'; shift = 1; break;
497 if (t >= 'A' && t <= 'F') t -= 'A'-'9'-1;
498 else if (t >= 'a' && t <= 'f') t -= 'a'-'9'-1;
502 if (t >= 'A' && t <= 'F') t -= 'A'-'9'-1;
503 else if (t >= 'a' && t <= 'f') t -= 'a'-'9'-1;
510 memmove(s+1, s+shift+1, len-shift);
517 /****************************************************************************/
522 /*************************************************
524 *************************************************/
526 const char * const HELP_MESSAGE = "\n\
534 [-tn] n seconds timeout\n\
537 [<outgoing interface>]\n\
543 main(int argc, char **argv)
545 struct sockaddr *s_ptr;
546 struct sockaddr_in s_in4;
547 char *interface = NULL;
548 char *address = NULL;
549 char *certfile = NULL;
550 char *keyfile = NULL;
553 int host_af, port, s_len, rc, sock, save_errno;
556 int sent_starttls = 0;
557 int tls_on_connect = 0;
561 struct sockaddr_in6 s_in6;
569 unsigned char outbuffer[10240];
570 unsigned char inbuffer[10240];
571 unsigned char *inptr = inbuffer;
573 *inptr = 0; /* Buffer empty */
577 while (argc >= argi + 1 && argv[argi][0] == '-')
579 if (strcmp(argv[argi], "-help") == 0 ||
580 strcmp(argv[argi], "--help") == 0 ||
581 strcmp(argv[argi], "-h") == 0)
586 if (strcmp(argv[argi], "-tls-on-connect") == 0)
592 else if (strcmp(argv[argi], "-ocsp") == 0)
594 if (argc < ++argi + 1)
596 fprintf(stderr, "Missing required certificate file for ocsp option\n");
599 ocsp_stapling = argv[argi++];
603 else if (argv[argi][1] == 't' && isdigit(argv[argi][2]))
605 tmplong = strtol(argv[argi]+2, &end, 10);
606 if (end == argv[argi]+2 || *end)
608 fprintf(stderr, "Failed to parse seconds from option <%s>\n",
612 if (tmplong > 10000L)
614 fprintf(stderr, "Unreasonably long wait of %ld seconds requested\n",
620 fprintf(stderr, "Timeout must not be negative (%ld)\n", tmplong);
623 timeout = (int) tmplong;
628 fprintf(stderr, "Unrecognized option %s\n", argv[argi]);
633 /* Mandatory 1st arg is IP address */
637 fprintf(stderr, "No IP address given\n");
641 address = argv[argi++];
642 host_af = (strchr(address, ':') != NULL)? AF_INET6 : AF_INET;
644 /* Mandatory 2nd arg is port */
648 fprintf(stderr, "No port number given\n");
652 port = atoi(argv[argi++]);
654 /* Optional next arg is interface */
657 (isdigit((unsigned char)argv[argi][0]) || argv[argi][0] == ':'))
658 interface = argv[argi++];
660 /* Any more arguments are the name of a certificate file and key file */
662 if (argc > argi) certfile = argv[argi++];
663 if (argc > argi) keyfile = argv[argi++];
667 /* For an IPv6 address, use an IPv6 sockaddr structure. */
669 if (host_af == AF_INET6)
671 s_ptr = (struct sockaddr *)&s_in6;
672 s_len = sizeof(s_in6);
677 /* For an IPv4 address, use an IPv4 sockaddr structure,
678 even on an IPv6 system. */
681 s_ptr = (struct sockaddr *)&s_in4;
682 s_len = sizeof(s_in4);
685 printf("Connecting to %s port %d ... ", address, port);
687 sock = socket(host_af, SOCK_STREAM, 0);
690 printf("socket creation failed: %s\n", strerror(errno));
694 /* Bind to a specific interface if requested. On an IPv6 system, this has
695 to be of the same family as the address we are calling. On an IPv4 system the
696 test is redundant, but it keeps the code tidier. */
698 if (interface != NULL)
700 int interface_af = (strchr(interface, ':') != NULL)? AF_INET6 : AF_INET;
702 if (interface_af == host_af)
706 /* Set up for IPv6 binding */
708 if (host_af == AF_INET6)
710 memset(&s_in6, 0, sizeof(s_in6));
711 s_in6.sin6_family = AF_INET6;
713 if (inet_pton(AF_INET6, interface, &s_in6.sin6_addr) != 1)
715 printf("Unable to parse \"%s\"", interface);
722 /* Set up for IPv4 binding */
725 memset(&s_in4, 0, sizeof(s_in4));
726 s_in4.sin_family = AF_INET;
728 s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(interface);
733 if (bind(sock, s_ptr, s_len) < 0)
735 printf("Unable to bind outgoing SMTP call to %s: %s",
736 interface, strerror(errno));
742 /* Set up a remote IPv6 address */
745 if (host_af == AF_INET6)
747 memset(&s_in6, 0, sizeof(s_in6));
748 s_in6.sin6_family = AF_INET6;
749 s_in6.sin6_port = htons(port);
750 if (inet_pton(host_af, address, &s_in6.sin6_addr) != 1)
752 printf("Unable to parse \"%s\"", address);
759 /* Set up a remote IPv4 address */
762 memset(&s_in4, 0, sizeof(s_in4));
763 s_in4.sin_family = AF_INET;
764 s_in4.sin_port = htons(port);
765 s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(address);
768 /* SIGALRM handler crashes out */
770 signal(SIGALRM, sigalrm_handler_crash);
772 rc = connect(sock, s_ptr, s_len);
776 /* A failure whose error code is "Interrupted system call" is in fact
777 an externally applied timeout if the signal handler has been run. */
782 printf("connect failed: %s\n", strerror(save_errno));
786 printf("connected\n");
789 /* --------------- Set up for OpenSSL --------------- */
793 SSL_load_error_strings();
795 ctx = SSL_CTX_new(SSLv23_method());
798 printf ("SSL_CTX_new failed\n");
802 if (certfile != NULL)
804 if (!SSL_CTX_use_certificate_file(ctx, certfile, SSL_FILETYPE_PEM))
806 printf("SSL_CTX_use_certificate_file failed\n");
809 printf("Certificate file = %s\n", certfile);
814 if (!SSL_CTX_use_PrivateKey_file(ctx, keyfile, SSL_FILETYPE_PEM))
816 printf("SSL_CTX_use_PrivateKey_file failed\n");
819 printf("Key file = %s\n", keyfile);
822 SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_BOTH);
823 SSL_CTX_set_timeout(ctx, 200);
824 SSL_CTX_set_info_callback(ctx, (void (*)())info_callback);
828 /* --------------- Set up for GnuTLS --------------- */
831 if (certfile != NULL) printf("Certificate file = %s\n", certfile);
832 if (keyfile != NULL) printf("Key file = %s\n", keyfile);
833 tls_init(certfile, keyfile);
834 tls_session = tls_session_init();
837 gnutls_ocsp_status_request_enable_client(tls_session, NULL, 0, NULL);
839 gnutls_transport_set_ptr(tls_session, (gnutls_transport_ptr_t)(intptr_t)sock);
841 /* When the server asks for a certificate and the client does not have one,
842 there is a SIGPIPE error in the gnutls_handshake() function for some reason
843 that is not understood. As luck would have it, this has never hit Exim itself
844 because it ignores SIGPIPE errors. Doing the same here allows it all to work as
847 signal(SIGPIPE, SIG_IGN);
850 /* ---------------------------------------------- */
853 /* Start TLS session if configured to do so without STARTTLS */
858 printf("Attempting to start TLS\n");
861 tls_active = tls_start(sock, &ssl, ctx);
867 sigalrm_seen = FALSE;
870 rc = gnutls_handshake(tls_session);
871 } while (rc < 0 && gnutls_error_is_fatal(rc) == 0);
872 tls_active = rc >= 0;
875 if (!tls_active) printf("%s\n", gnutls_strerror(rc));
880 printf("Failed to start TLS\n");
881 #if defined(HAVE_GNUTLS) && defined(HAVE_OCSP)
882 else if ( ocsp_stapling
883 && gnutls_ocsp_status_request_is_checked(tls_session, 0) == 0)
884 printf("Failed to verify certificate status\n");
887 printf("Succeeded in starting TLS\n");
891 while (fgets(CS outbuffer, sizeof(outbuffer), stdin) != NULL)
893 int n = (int)strlen(CS outbuffer);
896 /* Strip trailing newline */
897 if (outbuffer[n-1] == '\n') outbuffer[--n] = 0;
899 /* Expect incoming */
901 if ( strncmp(CS outbuffer, "???", 3) == 0
902 && (outbuffer[3] == ' ' || outbuffer[3] == '*')
905 unsigned char *lineptr;
906 unsigned exp_eof = outbuffer[3] == '*';
908 printf("%s\n", outbuffer);
909 n = unescape_buf(outbuffer, n);
911 if (*inptr == 0) /* Refill input buffer */
916 rc = SSL_read (ssl, inbuffer, sizeof(inbuffer) - 1);
919 rc = gnutls_record_recv(tls_session, CS inbuffer, sizeof(inbuffer) - 1);
925 rc = read(sock, inbuffer, sizeof(inbuffer));
931 printf("Read error %s\n", strerror(errno));
937 printf("Expected EOF read\n");
942 printf("Unexpected EOF read\n");
948 printf("Expected EOF not read\n");
960 while (*inptr != 0 && *inptr != '\r' && *inptr != '\n') inptr++;
964 if (*inptr == '\n') inptr++;
967 printf("<<< %s\n", lineptr);
968 if (strncmp(CS lineptr, CS outbuffer + 4, n - 4) != 0)
970 printf("\n******** Input mismatch ********\n");
977 if (lineptr[0] == '2')
982 printf("Attempting to start TLS\n");
986 tls_active = tls_start(sock, &ssl, ctx);
992 sigalrm_seen = FALSE;
995 rc = gnutls_handshake(tls_session);
996 } while (rc < 0 && gnutls_error_is_fatal(rc) == 0);
997 tls_active = rc >= 0;
1000 if (!tls_active) printf("%s\n", gnutls_strerror(rc));
1006 printf("Failed to start TLS\n");
1010 else if (ocsp_stapling)
1012 if ((rc= gnutls_certificate_verify_peers2(tls_session, &verify)) < 0)
1014 printf("Failed to verify certificate: %s\n", gnutls_strerror(rc));
1017 else if (verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED))
1019 printf("Bad certificate\n");
1023 else if (gnutls_ocsp_status_request_is_checked(tls_session, 0) == 0)
1025 printf("Failed to verify certificate status\n");
1027 gnutls_datum_t stapling;
1028 gnutls_ocsp_resp_t resp;
1029 gnutls_datum_t printed;
1030 if ( (rc= gnutls_ocsp_status_request_get(tls_session, &stapling)) == 0
1031 && (rc= gnutls_ocsp_resp_init(&resp)) == 0
1032 && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0
1033 && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_FULL, &printed)) == 0
1036 fprintf(stderr, "%.4096s", printed.data);
1037 gnutls_free(printed.data);
1040 (void) fprintf(stderr,"ocsp decode: %s", gnutls_strerror(rc));
1048 printf("Succeeded in starting TLS\n");
1050 else printf("Abandoning TLS start attempt\n");
1056 /* Wait for a bit before proceeding */
1058 else if (strncmp(CS outbuffer, "+++ ", 4) == 0)
1060 printf("%s\n", outbuffer);
1061 sleep(atoi(CS outbuffer + 4));
1064 /* Send outgoing, but barf if unconsumed incoming */
1068 unsigned char * out = outbuffer;
1070 if (strncmp(CS outbuffer, ">>> ", 4) == 0)
1079 printf("Unconsumed input: %s", inptr);
1080 printf(" About to send: %s\n", out);
1088 if (strcmp(CS out, "stoptls") == 0 ||
1089 strcmp(CS out, "STOPTLS") == 0)
1093 printf("STOPTLS read when TLS not active\n");
1096 printf("Shutting down TLS encryption\n");
1104 gnutls_bye(tls_session, GNUTLS_SHUT_WR);
1105 gnutls_deinit(tls_session);
1107 gnutls_global_deinit();
1114 /* Remember that we sent STARTTLS */
1116 sent_starttls = (strcmp(CS out, "starttls") == 0 ||
1117 strcmp(CS out, "STARTTLS") == 0);
1119 /* Fudge: if the command is "starttls_wait", we send the starttls bit,
1120 but we haven't set the flag, so that there is no negotiation. This is for
1121 testing the server's timeout. */
1123 if (strcmp(CS out, "starttls_wait") == 0)
1130 printf(">>> %s\n", out);
1133 strcpy(CS out + n, "\r\n");
1137 n = unescape_buf(out, n);
1145 rc = SSL_write (ssl, out, n);
1148 if ((rc = gnutls_record_send(tls_session, CS out, n)) < 0)
1150 printf("GnuTLS write error: %s\n", gnutls_strerror(rc));
1156 rc = write(sock, out, n);
1161 printf("Write error: %s\n", strerror(errno));
1167 printf("End of script\n");
1168 shutdown(sock, SHUT_WR);
1169 while ((rc = read(sock, inbuffer, sizeof(inbuffer))) > 0) ;
1175 /* End of client.c */