Annotation of ircnowd/src/ngircd/conn-ssl.c, Revision 1.1.1.1
1.1 tomglok 1: /*
2: * ngIRCd -- The Next Generation IRC Daemon
3: * Copyright (c)2005-2008 Florian Westphal (fw@strlen.de).
4: * Copyright (c)2008-2014 Alexander Barton (alex@barton.de) and Contributors.
5: *
6: * This program is free software; you can redistribute it and/or modify
7: * it under the terms of the GNU General Public License as published by
8: * the Free Software Foundation; either version 2 of the License, or
9: * (at your option) any later version.
10: * Please read the file COPYING, README and AUTHORS for more information.
11: */
12:
13: #include "portab.h"
14:
15: /**
16: * @file
17: * SSL wrapper functions
18: */
19:
20: #include "conf-ssl.h"
21:
22: #ifdef SSL_SUPPORT
23:
24: #include "io.h"
25: #include <assert.h>
26: #include <stdio.h>
27: #include <string.h>
28: #include <stdlib.h>
29: #include <errno.h>
30:
31: #define CONN_MODULE
32: #include "conn.h"
33: #include "conf.h"
34: #include "conn-func.h"
35: #include "conn-ssl.h"
36: #include "log.h"
37:
38: #include "defines.h"
39:
40: extern struct SSLOptions Conf_SSLOptions;
41:
42: #ifdef HAVE_LIBSSL
43: #include <openssl/err.h>
44: #include <openssl/rand.h>
45: #include <openssl/dh.h>
46:
47: static SSL_CTX * ssl_ctx;
48: static DH *dh_params;
49:
50: static bool ConnSSL_LoadServerKey_openssl PARAMS(( SSL_CTX *c ));
51: #endif
52:
53: #ifdef HAVE_LIBGNUTLS
54: #include <sys/types.h>
55: #include <sys/stat.h>
56: #include <fcntl.h>
57: #include <unistd.h>
58: #include <gnutls/x509.h>
59:
60: #define DH_BITS 2048
61: #define DH_BITS_MIN 1024
62:
63: #define MAX_HASH_SIZE 64 /* from gnutls-int.h */
64:
65: typedef struct {
66: int refcnt;
67: gnutls_certificate_credentials_t x509_cred;
68: gnutls_dh_params_t dh_params;
69: } x509_cred_slot;
70:
71: static array x509_creds = INIT_ARRAY;
72: static size_t x509_cred_idx;
73:
74: static gnutls_dh_params_t dh_params;
75: static gnutls_priority_t priorities_cache = NULL;
76: static bool ConnSSL_LoadServerKey_gnutls PARAMS(( void ));
77: #endif
78:
79: #define SHA256_STRING_LEN (32 * 2 + 1)
80:
81: static bool ConnSSL_Init_SSL PARAMS(( CONNECTION *c ));
82: static int ConnectAccept PARAMS(( CONNECTION *c, bool connect ));
83: static int ConnSSL_HandleError PARAMS(( CONNECTION *c, const int code, const char *fname ));
84:
85: #ifdef HAVE_LIBGNUTLS
86: static char * openreadclose(const char *name, size_t *len)
87: {
88: char *buf = NULL;
89: struct stat s;
90: ssize_t br;
91: int fd = open(name, O_RDONLY);
92: if (fd < 0) {
93: Log(LOG_ERR, "Could not open %s: %s", name, strerror(errno));
94: return NULL;
95: }
96: if (fstat(fd, &s)) {
97: Log(LOG_ERR, "Could not fstat %s: %s", name, strerror(errno));
98: goto out;
99: }
100: if (!S_ISREG(s.st_mode)) {
101: Log(LOG_ERR, "%s: Not a regular file", name);
102: goto out;
103: }
104: if (s.st_size <= 0) {
105: Log(LOG_ERR, "%s: invalid file length (size %ld <= 0)", name, (long) s.st_size);
106: goto out;
107: }
108: buf = malloc(s.st_size);
109: if (!buf) {
110: Log(LOG_ERR, "Could not malloc %lu bytes for file %s: %s", s.st_size, name, strerror(errno));
111: goto out;
112: }
113: br = read(fd, buf, s.st_size);
114: if (br != (ssize_t)s.st_size) {
115: Log(LOG_ERR, "Could not read file %s: read returned %ld, expected %ld: %s",
116: name, (long) br, (long) s.st_size, br == -1 ? strerror(errno):"short read?!");
117: memset(buf, 0, s.st_size);
118: free(buf);
119: buf = NULL;
120: } else {
121: *len = br;
122: }
123: out:
124: close(fd);
125: return buf;
126: }
127: #endif
128:
129:
130: #ifdef HAVE_LIBSSL
131: /**
132: * Log OpenSSL error message.
133: *
134: * @param msg The error message.
135: * @param info Additional information text or NULL.
136: */
137: static void
138: LogOpenSSLError(const char *error, const char *info)
139: {
140: unsigned long err = ERR_get_error();
141: char * errmsg = err
142: ? ERR_error_string(err, NULL)
143: : "Unable to determine error";
144:
145: assert(error != NULL);
146:
147: if (info)
148: Log(LOG_ERR, "%s: %s (%s)", error, info, errmsg);
149: else
150: Log(LOG_ERR, "%s: %s", error, errmsg);
151: }
152:
153:
154: static int
155: pem_passwd_cb(char *buf, int size, int rwflag, void *password)
156: {
157: array *pass = password;
158: int passlen;
159:
160: (void)rwflag; /* rwflag is unused if DEBUG is not set. */
161: assert(rwflag == 0); /* 0 -> callback used for decryption.
162: * See SSL_CTX_set_default_passwd_cb(3) */
163:
164: passlen = (int) array_bytes(pass);
165:
166: LogDebug("pem_passwd_cb buf size %d, array size %d", size, passlen);
167: assert(passlen >= 0);
168: if (passlen <= 0) {
169: Log(LOG_ERR, "PEM password required but not set [in pem_passwd_cb()]!");
170: return 0;
171: }
172: size = passlen > size ? size : passlen;
173: memcpy(buf, (char *)(array_start(pass)), size);
174: return size;
175: }
176:
177:
178: static int
179: Verify_openssl(UNUSED int preverify_ok, UNUSED X509_STORE_CTX *x509_ctx)
180: {
181: return 1;
182: }
183: #endif
184:
185:
186: static bool
187: Load_DH_params(void)
188: {
189: #ifdef HAVE_LIBSSL
190: FILE *fp;
191: bool ret = true;
192:
193: if (!Conf_SSLOptions.DHFile) {
194: Log(LOG_NOTICE, "Configuration option \"DHFile\" not set!");
195: return false;
196: }
197: fp = fopen(Conf_SSLOptions.DHFile, "r");
198: if (!fp) {
199: Log(LOG_ERR, "%s: %s", Conf_SSLOptions.DHFile, strerror(errno));
200: return false;
201: }
202: dh_params = PEM_read_DHparams(fp, NULL, NULL, NULL);
203: if (!dh_params) {
204: Log(LOG_ERR, "%s: Failed to read SSL DH parameters!",
205: Conf_SSLOptions.DHFile);
206: ret = false;
207: }
208: fclose(fp);
209: return ret;
210: #endif
211: #ifdef HAVE_LIBGNUTLS
212: bool need_dhgenerate = true;
213: int err;
214: gnutls_dh_params_t tmp_dh_params;
215:
216: err = gnutls_dh_params_init(&tmp_dh_params);
217: if (err < 0) {
218: Log(LOG_ERR, "Failed to initialize SSL DH parameters: %s",
219: gnutls_strerror(err));
220: return false;
221: }
222: if (Conf_SSLOptions.DHFile) {
223: gnutls_datum_t dhparms;
224: size_t size;
225: dhparms.data = (unsigned char *) openreadclose(Conf_SSLOptions.DHFile, &size);
226: if (dhparms.data) {
227: dhparms.size = size;
228: err = gnutls_dh_params_import_pkcs3(tmp_dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
229: if (err == 0)
230: need_dhgenerate = false;
231: else
232: Log(LOG_ERR,
233: "Failed to initialize SSL DH parameters: %s",
234: gnutls_strerror(err));
235:
236: memset(dhparms.data, 0, size);
237: free(dhparms.data);
238: }
239: }
240: if (need_dhgenerate) {
241: Log(LOG_WARNING,
242: "DHFile not set, generating %u bit DH parameters. This may take a while ...",
243: DH_BITS);
244: err = gnutls_dh_params_generate2(tmp_dh_params, DH_BITS);
245: if (err < 0) {
246: Log(LOG_ERR, "Failed to generate SSL DH parameters: %s",
247: gnutls_strerror(err));
248: return false;
249: }
250: }
251: dh_params = tmp_dh_params;
252: return true;
253: #endif
254: }
255:
256:
257: void ConnSSL_Free(CONNECTION *c)
258: {
259: #ifdef HAVE_LIBSSL
260: SSL *ssl = c->ssl_state.ssl;
261: if (ssl) {
262: SSL_shutdown(ssl);
263: SSL_free(ssl);
264: c->ssl_state.ssl = NULL;
265: if (c->ssl_state.fingerprint) {
266: free(c->ssl_state.fingerprint);
267: c->ssl_state.fingerprint = NULL;
268: }
269: }
270: #endif
271: #ifdef HAVE_LIBGNUTLS
272: gnutls_session_t sess = c->ssl_state.gnutls_session;
273: if (Conn_OPTION_ISSET(c, CONN_SSL)) {
274: gnutls_bye(sess, GNUTLS_SHUT_RDWR);
275: gnutls_deinit(sess);
276: }
277: x509_cred_slot *slot = array_get(&x509_creds, sizeof(x509_cred_slot), c->ssl_state.x509_cred_idx);
278: assert(slot != NULL);
279: assert(slot->refcnt > 0);
280: assert(slot->x509_cred != NULL);
281: slot->refcnt--;
282: if ((c->ssl_state.x509_cred_idx != x509_cred_idx) && (slot->refcnt <= 0)) {
283: Log(LOG_INFO, "Discarding X509 certificate credentials from slot %zd.",
284: c->ssl_state.x509_cred_idx);
285: gnutls_certificate_free_keys(slot->x509_cred);
286: gnutls_certificate_free_credentials(slot->x509_cred);
287: slot->x509_cred = NULL;
288: gnutls_dh_params_deinit(slot->dh_params);
289: slot->dh_params = NULL;
290: slot->refcnt = 0;
291: }
292: #endif
293: assert(Conn_OPTION_ISSET(c, CONN_SSL));
294: /* can't just set bitmask to 0 -- there are other, non-ssl related flags, e.g. CONN_ZIP. */
295: Conn_OPTION_DEL(c, CONN_SSL_FLAGS_ALL);
296: }
297:
298:
299: bool
300: ConnSSL_InitLibrary( void )
301: {
302: if (!Conf_SSLInUse()) {
303: LogDebug("SSL not in use, skipping initialization.");
304: return true;
305: }
306:
307: #ifdef HAVE_LIBSSL
308: SSL_CTX *newctx;
309:
310: #if OPENSSL_API_COMPAT < 0x10100000L
311: if (!ssl_ctx) {
312: SSL_library_init();
313: SSL_load_error_strings();
314: }
315: #endif
316:
317: if (!RAND_status()) {
318: Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?");
319: /*
320: * it is probably best to fail and let the user install EGD or
321: * a similar program if no kernel random device is available.
322: * According to OpenSSL RAND_egd(3): "The automatic query of
323: * /var/run/egd-pool et al was added in OpenSSL 0.9.7";
324: * so it makes little sense to deal with PRNGD seeding ourselves.
325: */
326: array_free(&Conf_SSLOptions.ListenPorts);
327: return false;
328: }
329:
330: newctx = SSL_CTX_new(SSLv23_method());
331: if (!newctx) {
332: LogOpenSSLError("Failed to create SSL context", NULL);
333: array_free(&Conf_SSLOptions.ListenPorts);
334: return false;
335: }
336:
337: if (!ConnSSL_LoadServerKey_openssl(newctx)) {
338: /* Failed to read new key but an old ssl context
339: * already exists -> reuse old context */
340: if (ssl_ctx) {
341: SSL_CTX_free(newctx);
342: Log(LOG_WARNING,
343: "Re-Initializing of SSL failed, using old keys!");
344: return true;
345: }
346: /* No preexisting old context -> error. */
347: goto out;
348: }
349:
350: if (SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0) {
351: Log(LOG_ERR, "Failed to apply OpenSSL cipher list \"%s\"!",
352: Conf_SSLOptions.CipherList);
353: goto out;
354: }
355:
356: SSL_CTX_set_session_id_context(newctx, (unsigned char *)"ngircd", 6);
357: SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
358: SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
359: SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
360: Verify_openssl);
361: SSL_CTX_free(ssl_ctx);
362: ssl_ctx = newctx;
363: Log(LOG_INFO, "%s initialized.", OpenSSL_version(OPENSSL_VERSION));
364: return true;
365: out:
366: SSL_CTX_free(newctx);
367: array_free(&Conf_SSLOptions.ListenPorts);
368: return false;
369: #endif
370: #ifdef HAVE_LIBGNUTLS
371: int err;
372: static bool initialized;
373:
374: if (!initialized) {
375: err = gnutls_global_init();
376: if (err) {
377: Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
378: gnutls_strerror(err));
379: goto out;
380: }
381: }
382:
383: if (!ConnSSL_LoadServerKey_gnutls())
384: goto out;
385:
386: if (priorities_cache != NULL) {
387: gnutls_priority_deinit(priorities_cache);
388: }
389: if (gnutls_priority_init(&priorities_cache, Conf_SSLOptions.CipherList,
390: NULL) != GNUTLS_E_SUCCESS) {
391: Log(LOG_ERR,
392: "Failed to apply GnuTLS cipher list \"%s\"!",
393: Conf_SSLOptions.CipherList);
394: goto out;
395: }
396:
397: Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
398: initialized = true;
399: return true;
400: out:
401: array_free(&Conf_SSLOptions.ListenPorts);
402: return false;
403: #endif
404: }
405:
406:
407: #ifdef HAVE_LIBGNUTLS
408: static bool
409: ConnSSL_LoadServerKey_gnutls(void)
410: {
411: int err;
412: const char *cert_file;
413:
414: x509_cred_slot *slot = NULL;
415: gnutls_certificate_credentials_t x509_cred;
416:
417: err = gnutls_certificate_allocate_credentials(&x509_cred);
418: if (err < 0) {
419: Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
420: gnutls_strerror(err));
421: return false;
422: }
423:
424: cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
425: if (!cert_file) {
426: Log(LOG_ERR, "No SSL server key configured!");
427: return false;
428: }
429:
430: if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
431: Log(LOG_WARNING,
432: "Ignoring SSL \"KeyFilePassword\": Not supported by GnuTLS.");
433:
434: if (!Load_DH_params())
435: return false;
436:
437: gnutls_certificate_set_dh_params(x509_cred, dh_params);
438: err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
439: if (err < 0) {
440: Log(LOG_ERR,
441: "Failed to set certificate key file (cert %s, key %s): %s",
442: cert_file,
443: Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
444: gnutls_strerror(err));
445: return false;
446: }
447:
448: /* Free currently active x509 context (if any) unless it is still in use */
449: slot = array_get(&x509_creds, sizeof(x509_cred_slot), x509_cred_idx);
450: if ((slot != NULL) && (slot->refcnt <= 0) && (slot->x509_cred != NULL)) {
451: Log(LOG_INFO, "Discarding X509 certificate credentials from slot %zd.", x509_cred_idx);
452: gnutls_certificate_free_keys(slot->x509_cred);
453: gnutls_certificate_free_credentials(slot->x509_cred);
454: slot->x509_cred = NULL;
455: gnutls_dh_params_deinit(slot->dh_params);
456: slot->dh_params = NULL;
457: slot->refcnt = 0;
458: }
459:
460: /* Find free slot */
461: x509_cred_idx = (size_t) -1;
462: size_t i;
463: for (slot = array_start(&x509_creds), i = 0;
464: i < array_length(&x509_creds, sizeof(x509_cred_slot));
465: slot++, i++) {
466: if (slot->refcnt <= 0) {
467: x509_cred_idx = i;
468: break;
469: }
470: }
471: /* ... allocate new slot otherwise. */
472: if (x509_cred_idx == (size_t) -1) {
473: x509_cred_idx = array_length(&x509_creds, sizeof(x509_cred_slot));
474: slot = array_alloc(&x509_creds, sizeof(x509_cred_slot), x509_cred_idx);
475: if (slot == NULL) {
476: Log(LOG_ERR, "Failed to allocate new slot for certificate credentials");
477: return false;
478: }
479: }
480: Log(LOG_INFO, "Storing new X509 certificate credentials in slot %zd.", x509_cred_idx);
481: slot->x509_cred = x509_cred;
482: slot->refcnt = 0;
483:
484: return true;
485: }
486: #endif
487:
488:
489: #ifdef HAVE_LIBSSL
490: static bool
491: ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
492: {
493: char *cert_key;
494:
495: assert(ctx);
496: if (!Conf_SSLOptions.KeyFile) {
497: Log(LOG_ERR, "No SSL server key configured!");
498: return false;
499: }
500:
501: SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
502: SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
503:
504: if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
505: array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
506: LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
507: return false;
508: }
509:
510: cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
511: if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
512: array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
513: LogOpenSSLError("Failed to load certificate chain", cert_key);
514: return false;
515: }
516:
517: array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
518:
519: if (!SSL_CTX_check_private_key(ctx)) {
520: LogOpenSSLError("Server private key does not match certificate", NULL);
521: return false;
522: }
523: if (Load_DH_params()) {
524: if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
525: LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
526: /* don't return false here: the non-DH modes will still work */
527: DH_free(dh_params);
528: dh_params = NULL;
529: }
530: return true;
531: }
532:
533:
534: #endif
535: static bool
536: ConnSSL_Init_SSL(CONNECTION *c)
537: {
538: int ret;
539:
540: LogDebug("Initializing SSL ...");
541: assert(c != NULL);
542:
543: #ifdef HAVE_LIBSSL
544: if (!ssl_ctx) {
545: Log(LOG_ERR,
546: "Can't initialize SSL context, OpenSSL initialization failed at startup!");
547: return false;
548: }
549: assert(c->ssl_state.ssl == NULL);
550: assert(c->ssl_state.fingerprint == NULL);
551:
552: c->ssl_state.ssl = SSL_new(ssl_ctx);
553: if (!c->ssl_state.ssl) {
554: LogOpenSSLError("Failed to create SSL structure", NULL);
555: return false;
556: }
557: Conn_OPTION_ADD(c, CONN_SSL);
558:
559: ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
560: if (ret != 1) {
561: LogOpenSSLError("Failed to set SSL file descriptor", NULL);
562: ConnSSL_Free(c);
563: return false;
564: }
565: #endif
566: #ifdef HAVE_LIBGNUTLS
567: Conn_OPTION_ADD(c, CONN_SSL);
568: ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
569: if (ret != GNUTLS_E_SUCCESS) {
570: Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
571: gnutls_strerror(ret));
572: ConnSSL_Free(c);
573: return false;
574: }
575: /*
576: * The intermediate (long) cast is here to avoid a warning like:
577: * "cast to pointer from integer of different size" on 64-bit platforms.
578: * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
579: * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
580: */
581: gnutls_transport_set_ptr(c->ssl_state.gnutls_session,
582: (gnutls_transport_ptr_t) (long) c->sock);
583: gnutls_certificate_server_set_request(c->ssl_state.gnutls_session,
584: GNUTLS_CERT_REQUEST);
585:
586: Log(LOG_INFO, "Using X509 credentials from slot %zd", x509_cred_idx);
587: c->ssl_state.x509_cred_idx = x509_cred_idx;
588: x509_cred_slot *slot = array_get(&x509_creds, sizeof(x509_cred_slot), x509_cred_idx);
589: slot->refcnt++;
590: ret = gnutls_credentials_set(c->ssl_state.gnutls_session,
591: GNUTLS_CRD_CERTIFICATE, slot->x509_cred);
592: if (ret != 0) {
593: Log(LOG_ERR, "Failed to set SSL credentials: %s",
594: gnutls_strerror(ret));
595: ConnSSL_Free(c);
596: return false;
597: }
598: gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
599: #endif
600: return true;
601: }
602:
603:
604: bool
605: ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
606: {
607: bool ret;
608: #ifdef HAVE_LIBGNUTLS
609: int err;
610:
611: err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
612: if (err) {
613: Log(LOG_ERR, "Failed to initialize new SSL session: %s",
614: gnutls_strerror(err));
615: return false;
616: }
617: #endif
618: ret = ConnSSL_Init_SSL(c);
619: if (!ret)
620: return false;
621: Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
622: #ifdef HAVE_LIBSSL
623: assert(c->ssl_state.ssl);
624: SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
625: #endif
626: return true;
627: }
628:
629:
630: /**
631: * Check and handle error return codes after failed calls to SSL functions.
632: *
633: * OpenSSL:
634: * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
635: * SSL_write() on ssl.
636: *
637: * GnuTLS:
638: * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
639: *
640: * @param c The connection handle.
641: * @prarm code The return code.
642: * @param fname The name of the function in which the error occurred.
643: * @return -1 on fatal errors, 0 if we can try again later.
644: */
645: static int
646: ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
647: {
648: #ifdef HAVE_LIBSSL
649: int ret = SSL_ERROR_SYSCALL;
650: unsigned long sslerr;
651: int real_errno = errno;
652:
653: ret = SSL_get_error(c->ssl_state.ssl, code);
654:
655: switch (ret) {
656: case SSL_ERROR_WANT_READ:
657: io_event_del(c->sock, IO_WANTWRITE);
658: Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
659: return 0; /* try again later */
660: case SSL_ERROR_WANT_WRITE:
661: io_event_del(c->sock, IO_WANTREAD);
662: Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
663: case SSL_ERROR_NONE:
664: return 0; /* try again later */
665: case SSL_ERROR_ZERO_RETURN:
666: LogDebug("SSL connection shut down normally.");
667: break;
668: case SSL_ERROR_SYSCALL:
669: /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
670: * and SSL_ERROR_WANT_X509_LOOKUP */
671: sslerr = ERR_get_error();
672: if (sslerr) {
673: Log(LOG_ERR, "SSL error: %s [in %s()]!",
674: ERR_error_string(sslerr, NULL), fname);
675: } else {
676: switch (code) { /* EOF that violated protocol */
677: case 0:
678: Log(LOG_ERR,
679: "SSL error, client disconnected [in %s()]!",
680: fname);
681: break;
682: case -1: /* low level socket I/O error, check errno */
683: Log(LOG_ERR, "SSL error: %s [in %s()]!",
684: strerror(real_errno), fname);
685: }
686: }
687: break;
688: case SSL_ERROR_SSL:
689: LogOpenSSLError("SSL protocol error", fname);
690: break;
691: default:
692: Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
693: }
694: ConnSSL_Free(c);
695: return -1;
696: #endif
697: #ifdef HAVE_LIBGNUTLS
698: switch (code) {
699: case GNUTLS_E_AGAIN:
700: case GNUTLS_E_INTERRUPTED:
701: if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
702: Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
703: io_event_del(c->sock, IO_WANTREAD);
704: } else {
705: Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
706: io_event_del(c->sock, IO_WANTWRITE);
707: }
708: break;
709: default:
710: assert(code < 0);
711: if (gnutls_error_is_fatal(code)) {
712: Log(LOG_ERR, "SSL error: %s [%s].",
713: gnutls_strerror(code), fname);
714: ConnSSL_Free(c);
715: return -1;
716: }
717: }
718: return 0;
719: #endif
720: }
721:
722:
723: static void
724: ConnSSL_LogCertInfo( CONNECTION *c )
725: {
726: #ifdef HAVE_LIBSSL
727: SSL *ssl = c->ssl_state.ssl;
728:
729: assert(ssl);
730:
731: Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
732: c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
733: #endif
734: #ifdef HAVE_LIBGNUTLS
735: gnutls_session_t sess = c->ssl_state.gnutls_session;
736: gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
737:
738: Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
739: c->sock,
740: gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
741: gnutls_cipher_get_name(cipher),
742: gnutls_mac_get_name(gnutls_mac_get(sess)));
743: #endif
744: }
745:
746:
747: /*
748: Accept incoming SSL connection.
749: Return Values:
750: 1: SSL Connection established
751: 0: try again
752: -1: SSL Connection not established due to fatal error.
753: */
754: int
755: ConnSSL_Accept( CONNECTION *c )
756: {
757: assert(c != NULL);
758: if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
759: #ifdef HAVE_LIBGNUTLS
760: int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
761: if (err) {
762: Log(LOG_ERR, "Failed to initialize new SSL session: %s",
763: gnutls_strerror(err));
764: return false;
765: }
766: #endif
767: if (!ConnSSL_Init_SSL(c))
768: return -1;
769: }
770: return ConnectAccept(c, false );
771: }
772:
773:
774: int
775: ConnSSL_Connect( CONNECTION *c )
776: {
777: assert(c != NULL);
778: #ifdef HAVE_LIBSSL
779: assert(c->ssl_state.ssl);
780: #endif
781: assert(Conn_OPTION_ISSET(c, CONN_SSL));
782: return ConnectAccept(c, true);
783: }
784:
785: static int
786: ConnSSL_InitCertFp( CONNECTION *c )
787: {
788: const char hex[] = "0123456789abcdef";
789: int i;
790:
791: #ifdef HAVE_LIBSSL
792: unsigned char digest[EVP_MAX_MD_SIZE];
793: unsigned int digest_size;
794: X509 *cert;
795:
796: cert = SSL_get_peer_certificate(c->ssl_state.ssl);
797: if (!cert)
798: return 0;
799:
800: if (!X509_digest(cert, EVP_sha256(), digest, &digest_size)) {
801: X509_free(cert);
802: return 0;
803: }
804:
805: X509_free(cert);
806: #endif /* HAVE_LIBSSL */
807: #ifdef HAVE_LIBGNUTLS
808: gnutls_x509_crt_t cert;
809: unsigned int cert_list_size;
810: const gnutls_datum_t *cert_list;
811: unsigned char digest[MAX_HASH_SIZE];
812: size_t digest_size;
813:
814: if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) !=
815: GNUTLS_CRT_X509)
816: return 0;
817:
818: if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
819: return 0;
820:
821: cert_list_size = 0;
822: cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
823: &cert_list_size);
824: if (!cert_list) {
825: gnutls_x509_crt_deinit(cert);
826: return 0;
827: }
828:
829: if (gnutls_x509_crt_import(cert, &cert_list[0],
830: GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
831: gnutls_x509_crt_deinit(cert);
832: return 0;
833: }
834:
835: digest_size = sizeof(digest);
836: if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA256, digest,
837: &digest_size)) {
838: gnutls_x509_crt_deinit(cert);
839: return 0;
840: }
841:
842: gnutls_x509_crt_deinit(cert);
843: #endif /* HAVE_LIBGNUTLS */
844:
845: assert(c->ssl_state.fingerprint == NULL);
846:
847: c->ssl_state.fingerprint = malloc(SHA256_STRING_LEN);
848: if (!c->ssl_state.fingerprint)
849: return 0;
850:
851: for (i = 0; i < (int)digest_size; i++) {
852: c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
853: c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
854: }
855: c->ssl_state.fingerprint[i * 2] = '\0';
856:
857: return 1;
858: }
859:
860: /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
861: static int
862: ConnectAccept( CONNECTION *c, bool connect)
863: {
864: int ret;
865: #ifdef HAVE_LIBSSL
866: SSL *ssl = c->ssl_state.ssl;
867: assert(ssl != NULL);
868:
869: ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
870: if (1 != ret)
871: return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
872: #endif
873: #ifdef HAVE_LIBGNUTLS
874: (void) connect;
875: ret = gnutls_handshake(c->ssl_state.gnutls_session);
876: if (ret)
877: return ConnSSL_HandleError(c, ret, "gnutls_handshake");
878: #endif /* _GNUTLS */
879: (void)ConnSSL_InitCertFp(c);
880:
881: Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
882: ConnSSL_LogCertInfo(c);
883:
884: Conn_StartLogin(CONNECTION2ID(c));
885: return 1;
886: }
887:
888:
889: ssize_t
890: ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
891: {
892: ssize_t bw;
893:
894: Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
895:
896: assert(count > 0);
897: #ifdef HAVE_LIBSSL
898: bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
899: #endif
900: #ifdef HAVE_LIBGNUTLS
901: bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
902: #endif
903: if (bw > 0)
904: return bw;
905: if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
906: errno = EAGAIN; /* try again */
907: return -1;
908: }
909:
910:
911: ssize_t
912: ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
913: {
914: ssize_t br;
915:
916: Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
917: #ifdef HAVE_LIBSSL
918: br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
919: if (br > 0) /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
920: return br;
921: #endif
922: #ifdef HAVE_LIBGNUTLS
923: br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
924: if (br >= 0) /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
925: return br;
926: #endif
927: /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
928: if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
929: errno = EAGAIN;
930: return -1;
931: }
932: return 0;
933: }
934:
935:
936: bool
937: ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
938: {
939: #ifdef HAVE_LIBSSL
940: char *nl;
941: SSL *ssl = c->ssl_state.ssl;
942:
943: if (!ssl)
944: return false;
945: *buf = 0;
946: SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
947: nl = strchr(buf, '\n');
948: if (nl)
949: *nl = 0;
950: return true;
951: #endif
952: #ifdef HAVE_LIBGNUTLS
953: if (Conn_OPTION_ISSET(c, CONN_SSL)) {
954: const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
955: unsigned keysize;
956:
957: gnutls_session_t sess = c->ssl_state.gnutls_session;
958: gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
959: name_cipher = gnutls_cipher_get_name(cipher);
960: name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
961: keysize = gnutls_cipher_get_key_size(cipher) * 8;
962: name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
963: name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
964:
965: return snprintf(buf, len, "%s-%s%15s Kx=%s Enc=%s(%u) Mac=%s",
966: name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
967: }
968: return false;
969: #endif
970: }
971:
972: char *
973: ConnSSL_GetCertFp(CONNECTION *c)
974: {
975: return c->ssl_state.fingerprint;
976: }
977:
978: bool
979: ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
980: {
981: assert (c != NULL);
982: c->ssl_state.fingerprint = strndup(fingerprint, SHA256_STRING_LEN - 1);
983: return c->ssl_state.fingerprint != NULL;
984: }
985: #else
986:
987: bool
988: ConnSSL_InitLibrary(void)
989: {
990: return true;
991: }
992:
993: #endif /* SSL_SUPPORT */
994: /* -eof- */
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