Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * be-secure-openssl.c
4 : * functions for OpenSSL support in the backend.
5 : *
6 : *
7 : * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
8 : * Portions Copyright (c) 1994, Regents of the University of California
9 : *
10 : *
11 : * IDENTIFICATION
12 : * src/backend/libpq/be-secure-openssl.c
13 : *
14 : *-------------------------------------------------------------------------
15 : */
16 :
17 : #include "postgres.h"
18 :
19 : #include <sys/stat.h>
20 : #include <signal.h>
21 : #include <fcntl.h>
22 : #include <ctype.h>
23 : #include <sys/socket.h>
24 : #include <unistd.h>
25 : #include <netdb.h>
26 : #include <netinet/in.h>
27 : #include <netinet/tcp.h>
28 : #include <arpa/inet.h>
29 :
30 : #include "common/string.h"
31 : #include "libpq/libpq.h"
32 : #include "miscadmin.h"
33 : #include "pgstat.h"
34 : #include "storage/fd.h"
35 : #include "storage/latch.h"
36 : #include "tcop/tcopprot.h"
37 : #include "utils/builtins.h"
38 : #include "utils/memutils.h"
39 :
40 : /*
41 : * These SSL-related #includes must come after all system-provided headers.
42 : * This ensures that OpenSSL can take care of conflicts with Windows'
43 : * <wincrypt.h> by #undef'ing the conflicting macros. (We don't directly
44 : * include <wincrypt.h>, but some other Windows headers do.)
45 : */
46 : #include "common/openssl.h"
47 : #include <openssl/conf.h>
48 : #include <openssl/dh.h>
49 : #ifndef OPENSSL_NO_ECDH
50 : #include <openssl/ec.h>
51 : #endif
52 : #include <openssl/x509v3.h>
53 :
54 :
55 : /* default init hook can be overridden by a shared library */
56 : static void default_openssl_tls_init(SSL_CTX *context, bool isServerStart);
57 : openssl_tls_init_hook_typ openssl_tls_init_hook = default_openssl_tls_init;
58 :
59 : static int my_sock_read(BIO *h, char *buf, int size);
60 : static int my_sock_write(BIO *h, const char *buf, int size);
61 : static BIO_METHOD *my_BIO_s_socket(void);
62 : static int my_SSL_set_fd(Port *port, int fd);
63 :
64 : static DH *load_dh_file(char *filename, bool isServerStart);
65 : static DH *load_dh_buffer(const char *buffer, size_t len);
66 : static int ssl_external_passwd_cb(char *buf, int size, int rwflag, void *userdata);
67 : static int dummy_ssl_passwd_cb(char *buf, int size, int rwflag, void *userdata);
68 : static int verify_cb(int ok, X509_STORE_CTX *ctx);
69 : static void info_cb(const SSL *ssl, int type, int args);
70 : static int alpn_cb(SSL *ssl,
71 : const unsigned char **out,
72 : unsigned char *outlen,
73 : const unsigned char *in,
74 : unsigned int inlen,
75 : void *userdata);
76 : static bool initialize_dh(SSL_CTX *context, bool isServerStart);
77 : static bool initialize_ecdh(SSL_CTX *context, bool isServerStart);
78 : static const char *SSLerrmessage(unsigned long ecode);
79 :
80 : static char *X509_NAME_to_cstring(X509_NAME *name);
81 :
82 : static SSL_CTX *SSL_context = NULL;
83 : static bool SSL_initialized = false;
84 : static bool dummy_ssl_passwd_cb_called = false;
85 : static bool ssl_is_server_start;
86 :
87 : static int ssl_protocol_version_to_openssl(int v);
88 : static const char *ssl_protocol_version_to_string(int v);
89 :
90 : /* for passing data back from verify_cb() */
91 : static const char *cert_errdetail;
92 :
93 : /* ------------------------------------------------------------ */
94 : /* Public interface */
95 : /* ------------------------------------------------------------ */
96 :
97 : int
98 52 : be_tls_init(bool isServerStart)
99 : {
100 : SSL_CTX *context;
101 52 : int ssl_ver_min = -1;
102 52 : int ssl_ver_max = -1;
103 :
104 : /* This stuff need be done only once. */
105 52 : if (!SSL_initialized)
106 : {
107 : #ifdef HAVE_OPENSSL_INIT_SSL
108 52 : OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
109 : #else
110 : OPENSSL_config(NULL);
111 : SSL_library_init();
112 : SSL_load_error_strings();
113 : #endif
114 52 : SSL_initialized = true;
115 : }
116 :
117 : /*
118 : * Create a new SSL context into which we'll load all the configuration
119 : * settings. If we fail partway through, we can avoid memory leakage by
120 : * freeing this context; we don't install it as active until the end.
121 : *
122 : * We use SSLv23_method() because it can negotiate use of the highest
123 : * mutually supported protocol version, while alternatives like
124 : * TLSv1_2_method() permit only one specific version. Note that we don't
125 : * actually allow SSL v2 or v3, only TLS protocols (see below).
126 : */
127 52 : context = SSL_CTX_new(SSLv23_method());
128 52 : if (!context)
129 : {
130 0 : ereport(isServerStart ? FATAL : LOG,
131 : (errmsg("could not create SSL context: %s",
132 : SSLerrmessage(ERR_get_error()))));
133 0 : goto error;
134 : }
135 :
136 : /*
137 : * Disable OpenSSL's moving-write-buffer sanity check, because it causes
138 : * unnecessary failures in nonblocking send cases.
139 : */
140 52 : SSL_CTX_set_mode(context, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
141 :
142 : /*
143 : * Call init hook (usually to set password callback)
144 : */
145 52 : (*openssl_tls_init_hook) (context, isServerStart);
146 :
147 : /* used by the callback */
148 52 : ssl_is_server_start = isServerStart;
149 :
150 : /*
151 : * Load and verify server's certificate and private key
152 : */
153 52 : if (SSL_CTX_use_certificate_chain_file(context, ssl_cert_file) != 1)
154 : {
155 0 : ereport(isServerStart ? FATAL : LOG,
156 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
157 : errmsg("could not load server certificate file \"%s\": %s",
158 : ssl_cert_file, SSLerrmessage(ERR_get_error()))));
159 0 : goto error;
160 : }
161 :
162 52 : if (!check_ssl_key_file_permissions(ssl_key_file, isServerStart))
163 0 : goto error;
164 :
165 : /*
166 : * OK, try to load the private key file.
167 : */
168 52 : dummy_ssl_passwd_cb_called = false;
169 :
170 52 : if (SSL_CTX_use_PrivateKey_file(context,
171 : ssl_key_file,
172 : SSL_FILETYPE_PEM) != 1)
173 : {
174 4 : if (dummy_ssl_passwd_cb_called)
175 0 : ereport(isServerStart ? FATAL : LOG,
176 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
177 : errmsg("private key file \"%s\" cannot be reloaded because it requires a passphrase",
178 : ssl_key_file)));
179 : else
180 4 : ereport(isServerStart ? FATAL : LOG,
181 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
182 : errmsg("could not load private key file \"%s\": %s",
183 : ssl_key_file, SSLerrmessage(ERR_get_error()))));
184 0 : goto error;
185 : }
186 :
187 48 : if (SSL_CTX_check_private_key(context) != 1)
188 : {
189 0 : ereport(isServerStart ? FATAL : LOG,
190 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
191 : errmsg("check of private key failed: %s",
192 : SSLerrmessage(ERR_get_error()))));
193 0 : goto error;
194 : }
195 :
196 48 : if (ssl_min_protocol_version)
197 : {
198 48 : ssl_ver_min = ssl_protocol_version_to_openssl(ssl_min_protocol_version);
199 :
200 48 : if (ssl_ver_min == -1)
201 : {
202 0 : ereport(isServerStart ? FATAL : LOG,
203 : /*- translator: first %s is a GUC option name, second %s is its value */
204 : (errmsg("%s setting \"%s\" not supported by this build",
205 : "ssl_min_protocol_version",
206 : GetConfigOption("ssl_min_protocol_version",
207 : false, false))));
208 0 : goto error;
209 : }
210 :
211 48 : if (!SSL_CTX_set_min_proto_version(context, ssl_ver_min))
212 : {
213 0 : ereport(isServerStart ? FATAL : LOG,
214 : (errmsg("could not set minimum SSL protocol version")));
215 0 : goto error;
216 : }
217 : }
218 :
219 48 : if (ssl_max_protocol_version)
220 : {
221 2 : ssl_ver_max = ssl_protocol_version_to_openssl(ssl_max_protocol_version);
222 :
223 2 : if (ssl_ver_max == -1)
224 : {
225 0 : ereport(isServerStart ? FATAL : LOG,
226 : /*- translator: first %s is a GUC option name, second %s is its value */
227 : (errmsg("%s setting \"%s\" not supported by this build",
228 : "ssl_max_protocol_version",
229 : GetConfigOption("ssl_max_protocol_version",
230 : false, false))));
231 0 : goto error;
232 : }
233 :
234 2 : if (!SSL_CTX_set_max_proto_version(context, ssl_ver_max))
235 : {
236 0 : ereport(isServerStart ? FATAL : LOG,
237 : (errmsg("could not set maximum SSL protocol version")));
238 0 : goto error;
239 : }
240 : }
241 :
242 : /* Check compatibility of min/max protocols */
243 48 : if (ssl_min_protocol_version &&
244 : ssl_max_protocol_version)
245 : {
246 : /*
247 : * No need to check for invalid values (-1) for each protocol number
248 : * as the code above would have already generated an error.
249 : */
250 2 : if (ssl_ver_min > ssl_ver_max)
251 : {
252 2 : ereport(isServerStart ? FATAL : LOG,
253 : (errmsg("could not set SSL protocol version range"),
254 : errdetail("%s cannot be higher than %s",
255 : "ssl_min_protocol_version",
256 : "ssl_max_protocol_version")));
257 0 : goto error;
258 : }
259 : }
260 :
261 : /* disallow SSL session tickets */
262 46 : SSL_CTX_set_options(context, SSL_OP_NO_TICKET);
263 :
264 : /* disallow SSL session caching, too */
265 46 : SSL_CTX_set_session_cache_mode(context, SSL_SESS_CACHE_OFF);
266 :
267 : /* disallow SSL compression */
268 46 : SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
269 :
270 : /*
271 : * Disallow SSL renegotiation. This concerns only TLSv1.2 and older
272 : * protocol versions, as TLSv1.3 has no support for renegotiation.
273 : * SSL_OP_NO_RENEGOTIATION is available in OpenSSL since 1.1.0h (via a
274 : * backport from 1.1.1). SSL_OP_NO_CLIENT_RENEGOTIATION is available in
275 : * LibreSSL since 2.5.1 disallowing all client-initiated renegotiation
276 : * (this is usually on by default).
277 : */
278 : #ifdef SSL_OP_NO_RENEGOTIATION
279 46 : SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
280 : #endif
281 : #ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
282 : SSL_CTX_set_options(context, SSL_OP_NO_CLIENT_RENEGOTIATION);
283 : #endif
284 :
285 : /* set up ephemeral DH and ECDH keys */
286 46 : if (!initialize_dh(context, isServerStart))
287 0 : goto error;
288 46 : if (!initialize_ecdh(context, isServerStart))
289 0 : goto error;
290 :
291 : /* set up the allowed cipher list */
292 46 : if (SSL_CTX_set_cipher_list(context, SSLCipherSuites) != 1)
293 : {
294 0 : ereport(isServerStart ? FATAL : LOG,
295 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
296 : errmsg("could not set the cipher list (no valid ciphers available)")));
297 0 : goto error;
298 : }
299 :
300 : /* Let server choose order */
301 46 : if (SSLPreferServerCiphers)
302 46 : SSL_CTX_set_options(context, SSL_OP_CIPHER_SERVER_PREFERENCE);
303 :
304 : /*
305 : * Load CA store, so we can verify client certificates if needed.
306 : */
307 46 : if (ssl_ca_file[0])
308 : {
309 : STACK_OF(X509_NAME) * root_cert_list;
310 :
311 84 : if (SSL_CTX_load_verify_locations(context, ssl_ca_file, NULL) != 1 ||
312 42 : (root_cert_list = SSL_load_client_CA_file(ssl_ca_file)) == NULL)
313 : {
314 0 : ereport(isServerStart ? FATAL : LOG,
315 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
316 : errmsg("could not load root certificate file \"%s\": %s",
317 : ssl_ca_file, SSLerrmessage(ERR_get_error()))));
318 0 : goto error;
319 : }
320 :
321 : /*
322 : * Tell OpenSSL to send the list of root certs we trust to clients in
323 : * CertificateRequests. This lets a client with a keystore select the
324 : * appropriate client certificate to send to us. Also, this ensures
325 : * that the SSL context will "own" the root_cert_list and remember to
326 : * free it when no longer needed.
327 : */
328 42 : SSL_CTX_set_client_CA_list(context, root_cert_list);
329 :
330 : /*
331 : * Always ask for SSL client cert, but don't fail if it's not
332 : * presented. We might fail such connections later, depending on what
333 : * we find in pg_hba.conf.
334 : */
335 42 : SSL_CTX_set_verify(context,
336 : (SSL_VERIFY_PEER |
337 : SSL_VERIFY_CLIENT_ONCE),
338 : verify_cb);
339 : }
340 :
341 : /*----------
342 : * Load the Certificate Revocation List (CRL).
343 : * http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci803160,00.html
344 : *----------
345 : */
346 46 : if (ssl_crl_file[0] || ssl_crl_dir[0])
347 : {
348 42 : X509_STORE *cvstore = SSL_CTX_get_cert_store(context);
349 :
350 42 : if (cvstore)
351 : {
352 : /* Set the flags to check against the complete CRL chain */
353 84 : if (X509_STORE_load_locations(cvstore,
354 42 : ssl_crl_file[0] ? ssl_crl_file : NULL,
355 42 : ssl_crl_dir[0] ? ssl_crl_dir : NULL)
356 : == 1)
357 : {
358 42 : X509_STORE_set_flags(cvstore,
359 : X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL);
360 : }
361 0 : else if (ssl_crl_dir[0] == 0)
362 : {
363 0 : ereport(isServerStart ? FATAL : LOG,
364 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
365 : errmsg("could not load SSL certificate revocation list file \"%s\": %s",
366 : ssl_crl_file, SSLerrmessage(ERR_get_error()))));
367 0 : goto error;
368 : }
369 0 : else if (ssl_crl_file[0] == 0)
370 : {
371 0 : ereport(isServerStart ? FATAL : LOG,
372 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
373 : errmsg("could not load SSL certificate revocation list directory \"%s\": %s",
374 : ssl_crl_dir, SSLerrmessage(ERR_get_error()))));
375 0 : goto error;
376 : }
377 : else
378 : {
379 0 : ereport(isServerStart ? FATAL : LOG,
380 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
381 : errmsg("could not load SSL certificate revocation list file \"%s\" or directory \"%s\": %s",
382 : ssl_crl_file, ssl_crl_dir,
383 : SSLerrmessage(ERR_get_error()))));
384 0 : goto error;
385 : }
386 : }
387 : }
388 :
389 : /*
390 : * Success! Replace any existing SSL_context.
391 : */
392 46 : if (SSL_context)
393 0 : SSL_CTX_free(SSL_context);
394 :
395 46 : SSL_context = context;
396 :
397 : /*
398 : * Set flag to remember whether CA store has been loaded into SSL_context.
399 : */
400 46 : if (ssl_ca_file[0])
401 42 : ssl_loaded_verify_locations = true;
402 : else
403 4 : ssl_loaded_verify_locations = false;
404 :
405 46 : return 0;
406 :
407 : /* Clean up by releasing working context. */
408 0 : error:
409 0 : if (context)
410 0 : SSL_CTX_free(context);
411 0 : return -1;
412 : }
413 :
414 : void
415 246 : be_tls_destroy(void)
416 : {
417 246 : if (SSL_context)
418 0 : SSL_CTX_free(SSL_context);
419 246 : SSL_context = NULL;
420 246 : ssl_loaded_verify_locations = false;
421 246 : }
422 :
423 : int
424 226 : be_tls_open_server(Port *port)
425 : {
426 : int r;
427 : int err;
428 : int waitfor;
429 : unsigned long ecode;
430 : bool give_proto_hint;
431 :
432 : Assert(!port->ssl);
433 : Assert(!port->peer);
434 :
435 226 : if (!SSL_context)
436 : {
437 0 : ereport(COMMERROR,
438 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
439 : errmsg("could not initialize SSL connection: SSL context not set up")));
440 0 : return -1;
441 : }
442 :
443 : /* set up debugging/info callback */
444 226 : SSL_CTX_set_info_callback(SSL_context, info_cb);
445 :
446 : /* enable ALPN */
447 226 : SSL_CTX_set_alpn_select_cb(SSL_context, alpn_cb, port);
448 :
449 226 : if (!(port->ssl = SSL_new(SSL_context)))
450 : {
451 0 : ereport(COMMERROR,
452 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
453 : errmsg("could not initialize SSL connection: %s",
454 : SSLerrmessage(ERR_get_error()))));
455 0 : return -1;
456 : }
457 226 : if (!my_SSL_set_fd(port, port->sock))
458 : {
459 0 : ereport(COMMERROR,
460 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
461 : errmsg("could not set SSL socket: %s",
462 : SSLerrmessage(ERR_get_error()))));
463 0 : return -1;
464 : }
465 226 : port->ssl_in_use = true;
466 :
467 538 : aloop:
468 :
469 : /*
470 : * Prepare to call SSL_get_error() by clearing thread's OpenSSL error
471 : * queue. In general, the current thread's error queue must be empty
472 : * before the TLS/SSL I/O operation is attempted, or SSL_get_error() will
473 : * not work reliably. An extension may have failed to clear the
474 : * per-thread error queue following another call to an OpenSSL I/O
475 : * routine.
476 : */
477 538 : errno = 0;
478 538 : ERR_clear_error();
479 538 : r = SSL_accept(port->ssl);
480 538 : if (r <= 0)
481 : {
482 348 : err = SSL_get_error(port->ssl, r);
483 :
484 : /*
485 : * Other clients of OpenSSL in the backend may fail to call
486 : * ERR_get_error(), but we always do, so as to not cause problems for
487 : * OpenSSL clients that don't call ERR_clear_error() defensively. Be
488 : * sure that this happens by calling now. SSL_get_error() relies on
489 : * the OpenSSL per-thread error queue being intact, so this is the
490 : * earliest possible point ERR_get_error() may be called.
491 : */
492 348 : ecode = ERR_get_error();
493 348 : switch (err)
494 : {
495 312 : case SSL_ERROR_WANT_READ:
496 : case SSL_ERROR_WANT_WRITE:
497 : /* not allowed during connection establishment */
498 : Assert(!port->noblock);
499 :
500 : /*
501 : * No need to care about timeouts/interrupts here. At this
502 : * point authentication_timeout still employs
503 : * StartupPacketTimeoutHandler() which directly exits.
504 : */
505 312 : if (err == SSL_ERROR_WANT_READ)
506 312 : waitfor = WL_SOCKET_READABLE | WL_EXIT_ON_PM_DEATH;
507 : else
508 0 : waitfor = WL_SOCKET_WRITEABLE | WL_EXIT_ON_PM_DEATH;
509 :
510 312 : (void) WaitLatchOrSocket(MyLatch, waitfor, port->sock, 0,
511 : WAIT_EVENT_SSL_OPEN_SERVER);
512 312 : goto aloop;
513 8 : case SSL_ERROR_SYSCALL:
514 8 : if (r < 0 && errno != 0)
515 0 : ereport(COMMERROR,
516 : (errcode_for_socket_access(),
517 : errmsg("could not accept SSL connection: %m")));
518 : else
519 8 : ereport(COMMERROR,
520 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
521 : errmsg("could not accept SSL connection: EOF detected")));
522 8 : break;
523 28 : case SSL_ERROR_SSL:
524 28 : switch (ERR_GET_REASON(ecode))
525 : {
526 : /*
527 : * UNSUPPORTED_PROTOCOL, WRONG_VERSION_NUMBER, and
528 : * TLSV1_ALERT_PROTOCOL_VERSION have been observed
529 : * when trying to communicate with an old OpenSSL
530 : * library, or when the client and server specify
531 : * disjoint protocol ranges. NO_PROTOCOLS_AVAILABLE
532 : * occurs if there's a local misconfiguration (which
533 : * can happen despite our checks, if openssl.cnf
534 : * injects a limit we didn't account for). It's not
535 : * very clear what would make OpenSSL return the other
536 : * codes listed here, but a hint about protocol
537 : * versions seems like it's appropriate for all.
538 : */
539 0 : case SSL_R_NO_PROTOCOLS_AVAILABLE:
540 : case SSL_R_UNSUPPORTED_PROTOCOL:
541 : case SSL_R_BAD_PROTOCOL_VERSION_NUMBER:
542 : case SSL_R_UNKNOWN_PROTOCOL:
543 : case SSL_R_UNKNOWN_SSL_VERSION:
544 : case SSL_R_UNSUPPORTED_SSL_VERSION:
545 : case SSL_R_WRONG_SSL_VERSION:
546 : case SSL_R_WRONG_VERSION_NUMBER:
547 : case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
548 : #ifdef SSL_R_VERSION_TOO_HIGH
549 : case SSL_R_VERSION_TOO_HIGH:
550 : #endif
551 : #ifdef SSL_R_VERSION_TOO_LOW
552 : case SSL_R_VERSION_TOO_LOW:
553 : #endif
554 0 : give_proto_hint = true;
555 0 : break;
556 28 : default:
557 28 : give_proto_hint = false;
558 28 : break;
559 : }
560 28 : ereport(COMMERROR,
561 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
562 : errmsg("could not accept SSL connection: %s",
563 : SSLerrmessage(ecode)),
564 : cert_errdetail ? errdetail_internal("%s", cert_errdetail) : 0,
565 : give_proto_hint ?
566 : errhint("This may indicate that the client does not support any SSL protocol version between %s and %s.",
567 : ssl_min_protocol_version ?
568 : ssl_protocol_version_to_string(ssl_min_protocol_version) :
569 : MIN_OPENSSL_TLS_VERSION,
570 : ssl_max_protocol_version ?
571 : ssl_protocol_version_to_string(ssl_max_protocol_version) :
572 : MAX_OPENSSL_TLS_VERSION) : 0));
573 28 : cert_errdetail = NULL;
574 28 : break;
575 0 : case SSL_ERROR_ZERO_RETURN:
576 0 : ereport(COMMERROR,
577 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
578 : errmsg("could not accept SSL connection: EOF detected")));
579 0 : break;
580 0 : default:
581 0 : ereport(COMMERROR,
582 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
583 : errmsg("unrecognized SSL error code: %d",
584 : err)));
585 0 : break;
586 : }
587 36 : return -1;
588 : }
589 :
590 : /* Get the protocol selected by ALPN */
591 190 : port->alpn_used = false;
592 : {
593 : const unsigned char *selected;
594 : unsigned int len;
595 :
596 190 : SSL_get0_alpn_selected(port->ssl, &selected, &len);
597 :
598 : /* If ALPN is used, check that we negotiated the expected protocol */
599 190 : if (selected != NULL)
600 : {
601 190 : if (len == strlen(PG_ALPN_PROTOCOL) &&
602 190 : memcmp(selected, PG_ALPN_PROTOCOL, strlen(PG_ALPN_PROTOCOL)) == 0)
603 : {
604 190 : port->alpn_used = true;
605 : }
606 : else
607 : {
608 : /* shouldn't happen */
609 0 : ereport(COMMERROR,
610 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
611 : errmsg("received SSL connection request with unexpected ALPN protocol")));
612 : }
613 : }
614 : }
615 :
616 : /* Get client certificate, if available. */
617 190 : port->peer = SSL_get_peer_certificate(port->ssl);
618 :
619 : /* and extract the Common Name and Distinguished Name from it. */
620 190 : port->peer_cn = NULL;
621 190 : port->peer_dn = NULL;
622 190 : port->peer_cert_valid = false;
623 190 : if (port->peer != NULL)
624 : {
625 : int len;
626 58 : X509_NAME *x509name = X509_get_subject_name(port->peer);
627 : char *peer_dn;
628 58 : BIO *bio = NULL;
629 58 : BUF_MEM *bio_buf = NULL;
630 :
631 58 : len = X509_NAME_get_text_by_NID(x509name, NID_commonName, NULL, 0);
632 58 : if (len != -1)
633 : {
634 : char *peer_cn;
635 :
636 58 : peer_cn = MemoryContextAlloc(TopMemoryContext, len + 1);
637 58 : r = X509_NAME_get_text_by_NID(x509name, NID_commonName, peer_cn,
638 : len + 1);
639 58 : peer_cn[len] = '\0';
640 58 : if (r != len)
641 : {
642 : /* shouldn't happen */
643 0 : pfree(peer_cn);
644 0 : return -1;
645 : }
646 :
647 : /*
648 : * Reject embedded NULLs in certificate common name to prevent
649 : * attacks like CVE-2009-4034.
650 : */
651 58 : if (len != strlen(peer_cn))
652 : {
653 0 : ereport(COMMERROR,
654 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
655 : errmsg("SSL certificate's common name contains embedded null")));
656 0 : pfree(peer_cn);
657 0 : return -1;
658 : }
659 :
660 58 : port->peer_cn = peer_cn;
661 : }
662 :
663 58 : bio = BIO_new(BIO_s_mem());
664 58 : if (!bio)
665 : {
666 0 : if (port->peer_cn != NULL)
667 : {
668 0 : pfree(port->peer_cn);
669 0 : port->peer_cn = NULL;
670 : }
671 0 : return -1;
672 : }
673 :
674 : /*
675 : * RFC2253 is the closest thing to an accepted standard format for
676 : * DNs. We have documented how to produce this format from a
677 : * certificate. It uses commas instead of slashes for delimiters,
678 : * which make regular expression matching a bit easier. Also note that
679 : * it prints the Subject fields in reverse order.
680 : */
681 116 : if (X509_NAME_print_ex(bio, x509name, 0, XN_FLAG_RFC2253) == -1 ||
682 58 : BIO_get_mem_ptr(bio, &bio_buf) <= 0)
683 : {
684 0 : BIO_free(bio);
685 0 : if (port->peer_cn != NULL)
686 : {
687 0 : pfree(port->peer_cn);
688 0 : port->peer_cn = NULL;
689 : }
690 0 : return -1;
691 : }
692 58 : peer_dn = MemoryContextAlloc(TopMemoryContext, bio_buf->length + 1);
693 58 : memcpy(peer_dn, bio_buf->data, bio_buf->length);
694 58 : len = bio_buf->length;
695 58 : BIO_free(bio);
696 58 : peer_dn[len] = '\0';
697 58 : if (len != strlen(peer_dn))
698 : {
699 0 : ereport(COMMERROR,
700 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
701 : errmsg("SSL certificate's distinguished name contains embedded null")));
702 0 : pfree(peer_dn);
703 0 : if (port->peer_cn != NULL)
704 : {
705 0 : pfree(port->peer_cn);
706 0 : port->peer_cn = NULL;
707 : }
708 0 : return -1;
709 : }
710 :
711 58 : port->peer_dn = peer_dn;
712 :
713 58 : port->peer_cert_valid = true;
714 : }
715 :
716 190 : return 0;
717 : }
718 :
719 : void
720 226 : be_tls_close(Port *port)
721 : {
722 226 : if (port->ssl)
723 : {
724 226 : SSL_shutdown(port->ssl);
725 226 : SSL_free(port->ssl);
726 226 : port->ssl = NULL;
727 226 : port->ssl_in_use = false;
728 : }
729 :
730 226 : if (port->peer)
731 : {
732 58 : X509_free(port->peer);
733 58 : port->peer = NULL;
734 : }
735 :
736 226 : if (port->peer_cn)
737 : {
738 58 : pfree(port->peer_cn);
739 58 : port->peer_cn = NULL;
740 : }
741 :
742 226 : if (port->peer_dn)
743 : {
744 58 : pfree(port->peer_dn);
745 58 : port->peer_dn = NULL;
746 : }
747 226 : }
748 :
749 : ssize_t
750 722 : be_tls_read(Port *port, void *ptr, size_t len, int *waitfor)
751 : {
752 : ssize_t n;
753 : int err;
754 : unsigned long ecode;
755 :
756 722 : errno = 0;
757 722 : ERR_clear_error();
758 722 : n = SSL_read(port->ssl, ptr, len);
759 722 : err = SSL_get_error(port->ssl, n);
760 722 : ecode = (err != SSL_ERROR_NONE || n < 0) ? ERR_get_error() : 0;
761 722 : switch (err)
762 : {
763 482 : case SSL_ERROR_NONE:
764 : /* a-ok */
765 482 : break;
766 206 : case SSL_ERROR_WANT_READ:
767 206 : *waitfor = WL_SOCKET_READABLE;
768 206 : errno = EWOULDBLOCK;
769 206 : n = -1;
770 206 : break;
771 0 : case SSL_ERROR_WANT_WRITE:
772 0 : *waitfor = WL_SOCKET_WRITEABLE;
773 0 : errno = EWOULDBLOCK;
774 0 : n = -1;
775 0 : break;
776 0 : case SSL_ERROR_SYSCALL:
777 : /* leave it to caller to ereport the value of errno */
778 0 : if (n != -1 || errno == 0)
779 : {
780 0 : errno = ECONNRESET;
781 0 : n = -1;
782 : }
783 0 : break;
784 0 : case SSL_ERROR_SSL:
785 0 : ereport(COMMERROR,
786 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
787 : errmsg("SSL error: %s", SSLerrmessage(ecode))));
788 0 : errno = ECONNRESET;
789 0 : n = -1;
790 0 : break;
791 34 : case SSL_ERROR_ZERO_RETURN:
792 : /* connection was cleanly shut down by peer */
793 34 : n = 0;
794 34 : break;
795 0 : default:
796 0 : ereport(COMMERROR,
797 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
798 : errmsg("unrecognized SSL error code: %d",
799 : err)));
800 0 : errno = ECONNRESET;
801 0 : n = -1;
802 0 : break;
803 : }
804 :
805 722 : return n;
806 : }
807 :
808 : ssize_t
809 340 : be_tls_write(Port *port, void *ptr, size_t len, int *waitfor)
810 : {
811 : ssize_t n;
812 : int err;
813 : unsigned long ecode;
814 :
815 340 : errno = 0;
816 340 : ERR_clear_error();
817 340 : n = SSL_write(port->ssl, ptr, len);
818 340 : err = SSL_get_error(port->ssl, n);
819 340 : ecode = (err != SSL_ERROR_NONE || n < 0) ? ERR_get_error() : 0;
820 340 : switch (err)
821 : {
822 340 : case SSL_ERROR_NONE:
823 : /* a-ok */
824 340 : break;
825 0 : case SSL_ERROR_WANT_READ:
826 0 : *waitfor = WL_SOCKET_READABLE;
827 0 : errno = EWOULDBLOCK;
828 0 : n = -1;
829 0 : break;
830 0 : case SSL_ERROR_WANT_WRITE:
831 0 : *waitfor = WL_SOCKET_WRITEABLE;
832 0 : errno = EWOULDBLOCK;
833 0 : n = -1;
834 0 : break;
835 0 : case SSL_ERROR_SYSCALL:
836 :
837 : /*
838 : * Leave it to caller to ereport the value of errno. However, if
839 : * errno is still zero then assume it's a read EOF situation, and
840 : * report ECONNRESET. (This seems possible because SSL_write can
841 : * also do reads.)
842 : */
843 0 : if (n != -1 || errno == 0)
844 : {
845 0 : errno = ECONNRESET;
846 0 : n = -1;
847 : }
848 0 : break;
849 0 : case SSL_ERROR_SSL:
850 0 : ereport(COMMERROR,
851 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
852 : errmsg("SSL error: %s", SSLerrmessage(ecode))));
853 0 : errno = ECONNRESET;
854 0 : n = -1;
855 0 : break;
856 0 : case SSL_ERROR_ZERO_RETURN:
857 :
858 : /*
859 : * the SSL connection was closed, leave it to the caller to
860 : * ereport it
861 : */
862 0 : errno = ECONNRESET;
863 0 : n = -1;
864 0 : break;
865 0 : default:
866 0 : ereport(COMMERROR,
867 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
868 : errmsg("unrecognized SSL error code: %d",
869 : err)));
870 0 : errno = ECONNRESET;
871 0 : n = -1;
872 0 : break;
873 : }
874 :
875 340 : return n;
876 : }
877 :
878 : /* ------------------------------------------------------------ */
879 : /* Internal functions */
880 : /* ------------------------------------------------------------ */
881 :
882 : /*
883 : * Private substitute BIO: this does the sending and receiving using send() and
884 : * recv() instead. This is so that we can enable and disable interrupts
885 : * just while calling recv(). We cannot have interrupts occurring while
886 : * the bulk of OpenSSL runs, because it uses malloc() and possibly other
887 : * non-reentrant libc facilities. We also need to call send() and recv()
888 : * directly so it gets passed through the socket/signals layer on Win32.
889 : *
890 : * These functions are closely modelled on the standard socket BIO in OpenSSL;
891 : * see sock_read() and sock_write() in OpenSSL's crypto/bio/bss_sock.c.
892 : */
893 :
894 : static BIO_METHOD *my_bio_methods = NULL;
895 :
896 : static int
897 3798 : my_sock_read(BIO *h, char *buf, int size)
898 : {
899 3798 : int res = 0;
900 :
901 3798 : if (buf != NULL)
902 : {
903 3798 : res = secure_raw_read(((Port *) BIO_get_app_data(h)), buf, size);
904 3798 : BIO_clear_retry_flags(h);
905 3798 : if (res <= 0)
906 : {
907 : /* If we were interrupted, tell caller to retry */
908 526 : if (errno == EINTR || errno == EWOULDBLOCK || errno == EAGAIN)
909 : {
910 518 : BIO_set_retry_read(h);
911 : }
912 : }
913 : }
914 :
915 3798 : return res;
916 : }
917 :
918 : static int
919 1348 : my_sock_write(BIO *h, const char *buf, int size)
920 : {
921 1348 : int res = 0;
922 :
923 1348 : res = secure_raw_write(((Port *) BIO_get_app_data(h)), buf, size);
924 1348 : BIO_clear_retry_flags(h);
925 1348 : if (res <= 0)
926 : {
927 : /* If we were interrupted, tell caller to retry */
928 50 : if (errno == EINTR || errno == EWOULDBLOCK || errno == EAGAIN)
929 : {
930 0 : BIO_set_retry_write(h);
931 : }
932 : }
933 :
934 1348 : return res;
935 : }
936 :
937 : static BIO_METHOD *
938 226 : my_BIO_s_socket(void)
939 : {
940 226 : if (!my_bio_methods)
941 : {
942 226 : BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
943 : #ifdef HAVE_BIO_METH_NEW
944 : int my_bio_index;
945 :
946 226 : my_bio_index = BIO_get_new_index();
947 226 : if (my_bio_index == -1)
948 0 : return NULL;
949 226 : my_bio_index |= (BIO_TYPE_DESCRIPTOR | BIO_TYPE_SOURCE_SINK);
950 226 : my_bio_methods = BIO_meth_new(my_bio_index, "PostgreSQL backend socket");
951 226 : if (!my_bio_methods)
952 0 : return NULL;
953 452 : if (!BIO_meth_set_write(my_bio_methods, my_sock_write) ||
954 452 : !BIO_meth_set_read(my_bio_methods, my_sock_read) ||
955 452 : !BIO_meth_set_gets(my_bio_methods, BIO_meth_get_gets(biom)) ||
956 452 : !BIO_meth_set_puts(my_bio_methods, BIO_meth_get_puts(biom)) ||
957 452 : !BIO_meth_set_ctrl(my_bio_methods, BIO_meth_get_ctrl(biom)) ||
958 452 : !BIO_meth_set_create(my_bio_methods, BIO_meth_get_create(biom)) ||
959 452 : !BIO_meth_set_destroy(my_bio_methods, BIO_meth_get_destroy(biom)) ||
960 226 : !BIO_meth_set_callback_ctrl(my_bio_methods, BIO_meth_get_callback_ctrl(biom)))
961 : {
962 0 : BIO_meth_free(my_bio_methods);
963 0 : my_bio_methods = NULL;
964 0 : return NULL;
965 : }
966 : #else
967 : my_bio_methods = malloc(sizeof(BIO_METHOD));
968 : if (!my_bio_methods)
969 : return NULL;
970 : memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
971 : my_bio_methods->bread = my_sock_read;
972 : my_bio_methods->bwrite = my_sock_write;
973 : #endif
974 : }
975 226 : return my_bio_methods;
976 : }
977 :
978 : /* This should exactly match OpenSSL's SSL_set_fd except for using my BIO */
979 : static int
980 226 : my_SSL_set_fd(Port *port, int fd)
981 : {
982 226 : int ret = 0;
983 : BIO *bio;
984 : BIO_METHOD *bio_method;
985 :
986 226 : bio_method = my_BIO_s_socket();
987 226 : if (bio_method == NULL)
988 : {
989 0 : SSLerr(SSL_F_SSL_SET_FD, ERR_R_BUF_LIB);
990 0 : goto err;
991 : }
992 226 : bio = BIO_new(bio_method);
993 :
994 226 : if (bio == NULL)
995 : {
996 0 : SSLerr(SSL_F_SSL_SET_FD, ERR_R_BUF_LIB);
997 0 : goto err;
998 : }
999 226 : BIO_set_app_data(bio, port);
1000 :
1001 226 : BIO_set_fd(bio, fd, BIO_NOCLOSE);
1002 226 : SSL_set_bio(port->ssl, bio, bio);
1003 226 : ret = 1;
1004 226 : err:
1005 226 : return ret;
1006 : }
1007 :
1008 : /*
1009 : * Load precomputed DH parameters.
1010 : *
1011 : * To prevent "downgrade" attacks, we perform a number of checks
1012 : * to verify that the DBA-generated DH parameters file contains
1013 : * what we expect it to contain.
1014 : */
1015 : static DH *
1016 0 : load_dh_file(char *filename, bool isServerStart)
1017 : {
1018 : FILE *fp;
1019 0 : DH *dh = NULL;
1020 : int codes;
1021 :
1022 : /* attempt to open file. It's not an error if it doesn't exist. */
1023 0 : if ((fp = AllocateFile(filename, "r")) == NULL)
1024 : {
1025 0 : ereport(isServerStart ? FATAL : LOG,
1026 : (errcode_for_file_access(),
1027 : errmsg("could not open DH parameters file \"%s\": %m",
1028 : filename)));
1029 0 : return NULL;
1030 : }
1031 :
1032 0 : dh = PEM_read_DHparams(fp, NULL, NULL, NULL);
1033 0 : FreeFile(fp);
1034 :
1035 0 : if (dh == NULL)
1036 : {
1037 0 : ereport(isServerStart ? FATAL : LOG,
1038 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1039 : errmsg("could not load DH parameters file: %s",
1040 : SSLerrmessage(ERR_get_error()))));
1041 0 : return NULL;
1042 : }
1043 :
1044 : /* make sure the DH parameters are usable */
1045 0 : if (DH_check(dh, &codes) == 0)
1046 : {
1047 0 : ereport(isServerStart ? FATAL : LOG,
1048 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1049 : errmsg("invalid DH parameters: %s",
1050 : SSLerrmessage(ERR_get_error()))));
1051 0 : DH_free(dh);
1052 0 : return NULL;
1053 : }
1054 0 : if (codes & DH_CHECK_P_NOT_PRIME)
1055 : {
1056 0 : ereport(isServerStart ? FATAL : LOG,
1057 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1058 : errmsg("invalid DH parameters: p is not prime")));
1059 0 : DH_free(dh);
1060 0 : return NULL;
1061 : }
1062 0 : if ((codes & DH_NOT_SUITABLE_GENERATOR) &&
1063 0 : (codes & DH_CHECK_P_NOT_SAFE_PRIME))
1064 : {
1065 0 : ereport(isServerStart ? FATAL : LOG,
1066 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1067 : errmsg("invalid DH parameters: neither suitable generator or safe prime")));
1068 0 : DH_free(dh);
1069 0 : return NULL;
1070 : }
1071 :
1072 0 : return dh;
1073 : }
1074 :
1075 : /*
1076 : * Load hardcoded DH parameters.
1077 : *
1078 : * If DH parameters cannot be loaded from a specified file, we can load
1079 : * the hardcoded DH parameters supplied with the backend to prevent
1080 : * problems.
1081 : */
1082 : static DH *
1083 46 : load_dh_buffer(const char *buffer, size_t len)
1084 : {
1085 : BIO *bio;
1086 46 : DH *dh = NULL;
1087 :
1088 46 : bio = BIO_new_mem_buf(unconstify(char *, buffer), len);
1089 46 : if (bio == NULL)
1090 0 : return NULL;
1091 46 : dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
1092 46 : if (dh == NULL)
1093 0 : ereport(DEBUG2,
1094 : (errmsg_internal("DH load buffer: %s",
1095 : SSLerrmessage(ERR_get_error()))));
1096 46 : BIO_free(bio);
1097 :
1098 46 : return dh;
1099 : }
1100 :
1101 : /*
1102 : * Passphrase collection callback using ssl_passphrase_command
1103 : */
1104 : static int
1105 8 : ssl_external_passwd_cb(char *buf, int size, int rwflag, void *userdata)
1106 : {
1107 : /* same prompt as OpenSSL uses internally */
1108 8 : const char *prompt = "Enter PEM pass phrase:";
1109 :
1110 : Assert(rwflag == 0);
1111 :
1112 8 : return run_ssl_passphrase_command(prompt, ssl_is_server_start, buf, size);
1113 : }
1114 :
1115 : /*
1116 : * Dummy passphrase callback
1117 : *
1118 : * If OpenSSL is told to use a passphrase-protected server key, by default
1119 : * it will issue a prompt on /dev/tty and try to read a key from there.
1120 : * That's no good during a postmaster SIGHUP cycle, not to mention SSL context
1121 : * reload in an EXEC_BACKEND postmaster child. So override it with this dummy
1122 : * function that just returns an empty passphrase, guaranteeing failure.
1123 : */
1124 : static int
1125 0 : dummy_ssl_passwd_cb(char *buf, int size, int rwflag, void *userdata)
1126 : {
1127 : /* Set flag to change the error message we'll report */
1128 0 : dummy_ssl_passwd_cb_called = true;
1129 : /* And return empty string */
1130 : Assert(size > 0);
1131 0 : buf[0] = '\0';
1132 0 : return 0;
1133 : }
1134 :
1135 : /*
1136 : * Examines the provided certificate name, and if it's too long to log or
1137 : * contains unprintable ASCII, escapes and truncates it. The return value is
1138 : * always a new palloc'd string. (The input string is still modified in place,
1139 : * for ease of implementation.)
1140 : */
1141 : static char *
1142 20 : prepare_cert_name(char *name)
1143 : {
1144 20 : size_t namelen = strlen(name);
1145 20 : char *truncated = name;
1146 :
1147 : /*
1148 : * Common Names are 64 chars max, so for a common case where the CN is the
1149 : * last field, we can still print the longest possible CN with a
1150 : * 7-character prefix (".../CN=[64 chars]"), for a reasonable limit of 71
1151 : * characters.
1152 : */
1153 : #define MAXLEN 71
1154 :
1155 20 : if (namelen > MAXLEN)
1156 : {
1157 : /*
1158 : * Keep the end of the name, not the beginning, since the most
1159 : * specific field is likely to give users the most information.
1160 : */
1161 2 : truncated = name + namelen - MAXLEN;
1162 2 : truncated[0] = truncated[1] = truncated[2] = '.';
1163 2 : namelen = MAXLEN;
1164 : }
1165 :
1166 : #undef MAXLEN
1167 :
1168 20 : return pg_clean_ascii(truncated, 0);
1169 : }
1170 :
1171 : /*
1172 : * Certificate verification callback
1173 : *
1174 : * This callback allows us to examine intermediate problems during
1175 : * verification, for later logging.
1176 : *
1177 : * This callback also allows us to override the default acceptance
1178 : * criteria (e.g., accepting self-signed or expired certs), but
1179 : * for now we accept the default checks.
1180 : */
1181 : static int
1182 184 : verify_cb(int ok, X509_STORE_CTX *ctx)
1183 : {
1184 : int depth;
1185 : int errcode;
1186 : const char *errstring;
1187 : StringInfoData str;
1188 : X509 *cert;
1189 :
1190 184 : if (ok)
1191 : {
1192 : /* Nothing to do for the successful case. */
1193 174 : return ok;
1194 : }
1195 :
1196 : /* Pull all the information we have on the verification failure. */
1197 10 : depth = X509_STORE_CTX_get_error_depth(ctx);
1198 10 : errcode = X509_STORE_CTX_get_error(ctx);
1199 10 : errstring = X509_verify_cert_error_string(errcode);
1200 :
1201 10 : initStringInfo(&str);
1202 10 : appendStringInfo(&str,
1203 10 : _("Client certificate verification failed at depth %d: %s."),
1204 : depth, errstring);
1205 :
1206 10 : cert = X509_STORE_CTX_get_current_cert(ctx);
1207 10 : if (cert)
1208 : {
1209 : char *subject,
1210 : *issuer;
1211 : char *sub_prepared,
1212 : *iss_prepared;
1213 : char *serialno;
1214 : ASN1_INTEGER *sn;
1215 : BIGNUM *b;
1216 :
1217 : /*
1218 : * Get the Subject and Issuer for logging, but don't let maliciously
1219 : * huge certs flood the logs, and don't reflect non-ASCII bytes into
1220 : * it either.
1221 : */
1222 10 : subject = X509_NAME_to_cstring(X509_get_subject_name(cert));
1223 10 : sub_prepared = prepare_cert_name(subject);
1224 10 : pfree(subject);
1225 :
1226 10 : issuer = X509_NAME_to_cstring(X509_get_issuer_name(cert));
1227 10 : iss_prepared = prepare_cert_name(issuer);
1228 10 : pfree(issuer);
1229 :
1230 : /*
1231 : * Pull the serial number, too, in case a Subject is still ambiguous.
1232 : * This mirrors be_tls_get_peer_serial().
1233 : */
1234 10 : sn = X509_get_serialNumber(cert);
1235 10 : b = ASN1_INTEGER_to_BN(sn, NULL);
1236 10 : serialno = BN_bn2dec(b);
1237 :
1238 10 : appendStringInfoChar(&str, '\n');
1239 10 : appendStringInfo(&str,
1240 10 : _("Failed certificate data (unverified): subject \"%s\", serial number %s, issuer \"%s\"."),
1241 0 : sub_prepared, serialno ? serialno : _("unknown"),
1242 : iss_prepared);
1243 :
1244 10 : BN_free(b);
1245 10 : OPENSSL_free(serialno);
1246 10 : pfree(iss_prepared);
1247 10 : pfree(sub_prepared);
1248 : }
1249 :
1250 : /* Store our detail message to be logged later. */
1251 10 : cert_errdetail = str.data;
1252 :
1253 10 : return ok;
1254 : }
1255 :
1256 : /*
1257 : * This callback is used to copy SSL information messages
1258 : * into the PostgreSQL log.
1259 : */
1260 : static void
1261 5454 : info_cb(const SSL *ssl, int type, int args)
1262 : {
1263 : const char *desc;
1264 :
1265 5454 : desc = SSL_state_string_long(ssl);
1266 :
1267 5454 : switch (type)
1268 : {
1269 226 : case SSL_CB_HANDSHAKE_START:
1270 226 : ereport(DEBUG4,
1271 : (errmsg_internal("SSL: handshake start: \"%s\"", desc)));
1272 226 : break;
1273 190 : case SSL_CB_HANDSHAKE_DONE:
1274 190 : ereport(DEBUG4,
1275 : (errmsg_internal("SSL: handshake done: \"%s\"", desc)));
1276 190 : break;
1277 4276 : case SSL_CB_ACCEPT_LOOP:
1278 4276 : ereport(DEBUG4,
1279 : (errmsg_internal("SSL: accept loop: \"%s\"", desc)));
1280 4276 : break;
1281 538 : case SSL_CB_ACCEPT_EXIT:
1282 538 : ereport(DEBUG4,
1283 : (errmsg_internal("SSL: accept exit (%d): \"%s\"", args, desc)));
1284 538 : break;
1285 0 : case SSL_CB_CONNECT_LOOP:
1286 0 : ereport(DEBUG4,
1287 : (errmsg_internal("SSL: connect loop: \"%s\"", desc)));
1288 0 : break;
1289 0 : case SSL_CB_CONNECT_EXIT:
1290 0 : ereport(DEBUG4,
1291 : (errmsg_internal("SSL: connect exit (%d): \"%s\"", args, desc)));
1292 0 : break;
1293 52 : case SSL_CB_READ_ALERT:
1294 52 : ereport(DEBUG4,
1295 : (errmsg_internal("SSL: read alert (0x%04x): \"%s\"", args, desc)));
1296 52 : break;
1297 172 : case SSL_CB_WRITE_ALERT:
1298 172 : ereport(DEBUG4,
1299 : (errmsg_internal("SSL: write alert (0x%04x): \"%s\"", args, desc)));
1300 172 : break;
1301 : }
1302 5454 : }
1303 :
1304 : /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
1305 : static const unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
1306 :
1307 : /*
1308 : * Server callback for ALPN negotiation. We use the standard "helper" function
1309 : * even though currently we only accept one value.
1310 : */
1311 : static int
1312 432 : alpn_cb(SSL *ssl,
1313 : const unsigned char **out,
1314 : unsigned char *outlen,
1315 : const unsigned char *in,
1316 : unsigned int inlen,
1317 : void *userdata)
1318 : {
1319 : /*
1320 : * Why does OpenSSL provide a helper function that requires a nonconst
1321 : * vector when the callback is declared to take a const vector? What are
1322 : * we to do with that?
1323 : */
1324 : int retval;
1325 :
1326 : Assert(userdata != NULL);
1327 : Assert(out != NULL);
1328 : Assert(outlen != NULL);
1329 : Assert(in != NULL);
1330 :
1331 432 : retval = SSL_select_next_proto((unsigned char **) out, outlen,
1332 : alpn_protos, sizeof(alpn_protos),
1333 : in, inlen);
1334 432 : if (*out == NULL || *outlen > sizeof(alpn_protos) || *outlen <= 0)
1335 0 : return SSL_TLSEXT_ERR_NOACK; /* can't happen */
1336 :
1337 432 : if (retval == OPENSSL_NPN_NEGOTIATED)
1338 432 : return SSL_TLSEXT_ERR_OK;
1339 : else
1340 : {
1341 : /*
1342 : * The client doesn't support our protocol. Reject the connection
1343 : * with TLS "no_application_protocol" alert, per RFC 7301.
1344 : */
1345 0 : return SSL_TLSEXT_ERR_ALERT_FATAL;
1346 : }
1347 : }
1348 :
1349 :
1350 : /*
1351 : * Set DH parameters for generating ephemeral DH keys. The
1352 : * DH parameters can take a long time to compute, so they must be
1353 : * precomputed.
1354 : *
1355 : * Since few sites will bother to create a parameter file, we also
1356 : * provide a fallback to the parameters provided by the OpenSSL
1357 : * project.
1358 : *
1359 : * These values can be static (once loaded or computed) since the
1360 : * OpenSSL library can efficiently generate random keys from the
1361 : * information provided.
1362 : */
1363 : static bool
1364 46 : initialize_dh(SSL_CTX *context, bool isServerStart)
1365 : {
1366 46 : DH *dh = NULL;
1367 :
1368 46 : SSL_CTX_set_options(context, SSL_OP_SINGLE_DH_USE);
1369 :
1370 46 : if (ssl_dh_params_file[0])
1371 0 : dh = load_dh_file(ssl_dh_params_file, isServerStart);
1372 46 : if (!dh)
1373 46 : dh = load_dh_buffer(FILE_DH2048, sizeof(FILE_DH2048));
1374 46 : if (!dh)
1375 : {
1376 0 : ereport(isServerStart ? FATAL : LOG,
1377 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1378 : errmsg("DH: could not load DH parameters")));
1379 0 : return false;
1380 : }
1381 :
1382 46 : if (SSL_CTX_set_tmp_dh(context, dh) != 1)
1383 : {
1384 0 : ereport(isServerStart ? FATAL : LOG,
1385 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1386 : errmsg("DH: could not set DH parameters: %s",
1387 : SSLerrmessage(ERR_get_error()))));
1388 0 : DH_free(dh);
1389 0 : return false;
1390 : }
1391 :
1392 46 : DH_free(dh);
1393 46 : return true;
1394 : }
1395 :
1396 : /*
1397 : * Set ECDH parameters for generating ephemeral Elliptic Curve DH
1398 : * keys. This is much simpler than the DH parameters, as we just
1399 : * need to provide the name of the curve to OpenSSL.
1400 : */
1401 : static bool
1402 46 : initialize_ecdh(SSL_CTX *context, bool isServerStart)
1403 : {
1404 : #ifndef OPENSSL_NO_ECDH
1405 : EC_KEY *ecdh;
1406 : int nid;
1407 :
1408 46 : nid = OBJ_sn2nid(SSLECDHCurve);
1409 46 : if (!nid)
1410 : {
1411 0 : ereport(isServerStart ? FATAL : LOG,
1412 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1413 : errmsg("ECDH: unrecognized curve name: %s", SSLECDHCurve)));
1414 0 : return false;
1415 : }
1416 :
1417 46 : ecdh = EC_KEY_new_by_curve_name(nid);
1418 46 : if (!ecdh)
1419 : {
1420 0 : ereport(isServerStart ? FATAL : LOG,
1421 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1422 : errmsg("ECDH: could not create key")));
1423 0 : return false;
1424 : }
1425 :
1426 46 : SSL_CTX_set_options(context, SSL_OP_SINGLE_ECDH_USE);
1427 46 : SSL_CTX_set_tmp_ecdh(context, ecdh);
1428 46 : EC_KEY_free(ecdh);
1429 : #endif
1430 :
1431 46 : return true;
1432 : }
1433 :
1434 : /*
1435 : * Obtain reason string for passed SSL errcode
1436 : *
1437 : * ERR_get_error() is used by caller to get errcode to pass here.
1438 : *
1439 : * Some caution is needed here since ERR_reason_error_string will return NULL
1440 : * if it doesn't recognize the error code, or (in OpenSSL >= 3) if the code
1441 : * represents a system errno value. We don't want to return NULL ever.
1442 : */
1443 : static const char *
1444 32 : SSLerrmessage(unsigned long ecode)
1445 : {
1446 : const char *errreason;
1447 : static char errbuf[36];
1448 :
1449 32 : if (ecode == 0)
1450 0 : return _("no SSL error reported");
1451 32 : errreason = ERR_reason_error_string(ecode);
1452 32 : if (errreason != NULL)
1453 32 : return errreason;
1454 :
1455 : /*
1456 : * In OpenSSL 3.0.0 and later, ERR_reason_error_string randomly refuses to
1457 : * map system errno values. We can cover that shortcoming with this bit
1458 : * of code. Older OpenSSL versions don't have the ERR_SYSTEM_ERROR macro,
1459 : * but that's okay because they don't have the shortcoming either.
1460 : */
1461 : #ifdef ERR_SYSTEM_ERROR
1462 : if (ERR_SYSTEM_ERROR(ecode))
1463 : return strerror(ERR_GET_REASON(ecode));
1464 : #endif
1465 :
1466 : /* No choice but to report the numeric ecode */
1467 0 : snprintf(errbuf, sizeof(errbuf), _("SSL error code %lu"), ecode);
1468 0 : return errbuf;
1469 : }
1470 :
1471 : int
1472 304 : be_tls_get_cipher_bits(Port *port)
1473 : {
1474 : int bits;
1475 :
1476 304 : if (port->ssl)
1477 : {
1478 304 : SSL_get_cipher_bits(port->ssl, &bits);
1479 304 : return bits;
1480 : }
1481 : else
1482 0 : return 0;
1483 : }
1484 :
1485 : const char *
1486 306 : be_tls_get_version(Port *port)
1487 : {
1488 306 : if (port->ssl)
1489 306 : return SSL_get_version(port->ssl);
1490 : else
1491 0 : return NULL;
1492 : }
1493 :
1494 : const char *
1495 306 : be_tls_get_cipher(Port *port)
1496 : {
1497 306 : if (port->ssl)
1498 306 : return SSL_get_cipher(port->ssl);
1499 : else
1500 0 : return NULL;
1501 : }
1502 :
1503 : void
1504 152 : be_tls_get_peer_subject_name(Port *port, char *ptr, size_t len)
1505 : {
1506 152 : if (port->peer)
1507 54 : strlcpy(ptr, X509_NAME_to_cstring(X509_get_subject_name(port->peer)), len);
1508 : else
1509 98 : ptr[0] = '\0';
1510 152 : }
1511 :
1512 : void
1513 154 : be_tls_get_peer_issuer_name(Port *port, char *ptr, size_t len)
1514 : {
1515 154 : if (port->peer)
1516 56 : strlcpy(ptr, X509_NAME_to_cstring(X509_get_issuer_name(port->peer)), len);
1517 : else
1518 98 : ptr[0] = '\0';
1519 154 : }
1520 :
1521 : void
1522 154 : be_tls_get_peer_serial(Port *port, char *ptr, size_t len)
1523 : {
1524 154 : if (port->peer)
1525 : {
1526 : ASN1_INTEGER *serial;
1527 : BIGNUM *b;
1528 : char *decimal;
1529 :
1530 56 : serial = X509_get_serialNumber(port->peer);
1531 56 : b = ASN1_INTEGER_to_BN(serial, NULL);
1532 56 : decimal = BN_bn2dec(b);
1533 :
1534 56 : BN_free(b);
1535 56 : strlcpy(ptr, decimal, len);
1536 56 : OPENSSL_free(decimal);
1537 : }
1538 : else
1539 98 : ptr[0] = '\0';
1540 154 : }
1541 :
1542 : char *
1543 8 : be_tls_get_certificate_hash(Port *port, size_t *len)
1544 : {
1545 : X509 *server_cert;
1546 : char *cert_hash;
1547 8 : const EVP_MD *algo_type = NULL;
1548 : unsigned char hash[EVP_MAX_MD_SIZE]; /* size for SHA-512 */
1549 : unsigned int hash_size;
1550 : int algo_nid;
1551 :
1552 8 : *len = 0;
1553 8 : server_cert = SSL_get_certificate(port->ssl);
1554 8 : if (server_cert == NULL)
1555 0 : return NULL;
1556 :
1557 : /*
1558 : * Get the signature algorithm of the certificate to determine the hash
1559 : * algorithm to use for the result. Prefer X509_get_signature_info(),
1560 : * introduced in OpenSSL 1.1.1, which can handle RSA-PSS signatures.
1561 : */
1562 : #if HAVE_X509_GET_SIGNATURE_INFO
1563 8 : if (!X509_get_signature_info(server_cert, &algo_nid, NULL, NULL, NULL))
1564 : #else
1565 : if (!OBJ_find_sigid_algs(X509_get_signature_nid(server_cert),
1566 : &algo_nid, NULL))
1567 : #endif
1568 0 : elog(ERROR, "could not determine server certificate signature algorithm");
1569 :
1570 : /*
1571 : * The TLS server's certificate bytes need to be hashed with SHA-256 if
1572 : * its signature algorithm is MD5 or SHA-1 as per RFC 5929
1573 : * (https://tools.ietf.org/html/rfc5929#section-4.1). If something else
1574 : * is used, the same hash as the signature algorithm is used.
1575 : */
1576 8 : switch (algo_nid)
1577 : {
1578 0 : case NID_md5:
1579 : case NID_sha1:
1580 0 : algo_type = EVP_sha256();
1581 0 : break;
1582 8 : default:
1583 8 : algo_type = EVP_get_digestbynid(algo_nid);
1584 8 : if (algo_type == NULL)
1585 0 : elog(ERROR, "could not find digest for NID %s",
1586 : OBJ_nid2sn(algo_nid));
1587 8 : break;
1588 : }
1589 :
1590 : /* generate and save the certificate hash */
1591 8 : if (!X509_digest(server_cert, algo_type, hash, &hash_size))
1592 0 : elog(ERROR, "could not generate server certificate hash");
1593 :
1594 8 : cert_hash = palloc(hash_size);
1595 8 : memcpy(cert_hash, hash, hash_size);
1596 8 : *len = hash_size;
1597 :
1598 8 : return cert_hash;
1599 : }
1600 :
1601 : /*
1602 : * Convert an X509 subject name to a cstring.
1603 : *
1604 : */
1605 : static char *
1606 130 : X509_NAME_to_cstring(X509_NAME *name)
1607 : {
1608 130 : BIO *membuf = BIO_new(BIO_s_mem());
1609 : int i,
1610 : nid,
1611 130 : count = X509_NAME_entry_count(name);
1612 : X509_NAME_ENTRY *e;
1613 : ASN1_STRING *v;
1614 : const char *field_name;
1615 : size_t size;
1616 : char nullterm;
1617 : char *sp;
1618 : char *dp;
1619 : char *result;
1620 :
1621 130 : if (membuf == NULL)
1622 0 : ereport(ERROR,
1623 : (errcode(ERRCODE_OUT_OF_MEMORY),
1624 : errmsg("could not create BIO")));
1625 :
1626 130 : (void) BIO_set_close(membuf, BIO_CLOSE);
1627 282 : for (i = 0; i < count; i++)
1628 : {
1629 152 : e = X509_NAME_get_entry(name, i);
1630 152 : nid = OBJ_obj2nid(X509_NAME_ENTRY_get_object(e));
1631 152 : if (nid == NID_undef)
1632 0 : ereport(ERROR,
1633 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1634 : errmsg("could not get NID for ASN1_OBJECT object")));
1635 152 : v = X509_NAME_ENTRY_get_data(e);
1636 152 : field_name = OBJ_nid2sn(nid);
1637 152 : if (field_name == NULL)
1638 0 : field_name = OBJ_nid2ln(nid);
1639 152 : if (field_name == NULL)
1640 0 : ereport(ERROR,
1641 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1642 : errmsg("could not convert NID %d to an ASN1_OBJECT structure", nid)));
1643 152 : BIO_printf(membuf, "/%s=", field_name);
1644 152 : ASN1_STRING_print_ex(membuf, v,
1645 : ((ASN1_STRFLGS_RFC2253 & ~ASN1_STRFLGS_ESC_MSB)
1646 : | ASN1_STRFLGS_UTF8_CONVERT));
1647 : }
1648 :
1649 : /* ensure null termination of the BIO's content */
1650 130 : nullterm = '\0';
1651 130 : BIO_write(membuf, &nullterm, 1);
1652 130 : size = BIO_get_mem_data(membuf, &sp);
1653 130 : dp = pg_any_to_server(sp, size - 1, PG_UTF8);
1654 :
1655 130 : result = pstrdup(dp);
1656 130 : if (dp != sp)
1657 0 : pfree(dp);
1658 130 : if (BIO_free(membuf) != 1)
1659 0 : elog(ERROR, "could not free OpenSSL BIO structure");
1660 :
1661 130 : return result;
1662 : }
1663 :
1664 : /*
1665 : * Convert TLS protocol version GUC enum to OpenSSL values
1666 : *
1667 : * This is a straightforward one-to-one mapping, but doing it this way makes
1668 : * the definitions of ssl_min_protocol_version and ssl_max_protocol_version
1669 : * independent of OpenSSL availability and version.
1670 : *
1671 : * If a version is passed that is not supported by the current OpenSSL
1672 : * version, then we return -1. If a nonnegative value is returned,
1673 : * subsequent code can assume it's working with a supported version.
1674 : *
1675 : * Note: this is rather similar to libpq's routine in fe-secure-openssl.c,
1676 : * so make sure to update both routines if changing this one.
1677 : */
1678 : static int
1679 50 : ssl_protocol_version_to_openssl(int v)
1680 : {
1681 50 : switch (v)
1682 : {
1683 0 : case PG_TLS_ANY:
1684 0 : return 0;
1685 0 : case PG_TLS1_VERSION:
1686 0 : return TLS1_VERSION;
1687 2 : case PG_TLS1_1_VERSION:
1688 : #ifdef TLS1_1_VERSION
1689 2 : return TLS1_1_VERSION;
1690 : #else
1691 : break;
1692 : #endif
1693 48 : case PG_TLS1_2_VERSION:
1694 : #ifdef TLS1_2_VERSION
1695 48 : return TLS1_2_VERSION;
1696 : #else
1697 : break;
1698 : #endif
1699 0 : case PG_TLS1_3_VERSION:
1700 : #ifdef TLS1_3_VERSION
1701 0 : return TLS1_3_VERSION;
1702 : #else
1703 : break;
1704 : #endif
1705 : }
1706 :
1707 0 : return -1;
1708 : }
1709 :
1710 : /*
1711 : * Likewise provide a mapping to strings.
1712 : */
1713 : static const char *
1714 0 : ssl_protocol_version_to_string(int v)
1715 : {
1716 0 : switch (v)
1717 : {
1718 0 : case PG_TLS_ANY:
1719 0 : return "any";
1720 0 : case PG_TLS1_VERSION:
1721 0 : return "TLSv1";
1722 0 : case PG_TLS1_1_VERSION:
1723 0 : return "TLSv1.1";
1724 0 : case PG_TLS1_2_VERSION:
1725 0 : return "TLSv1.2";
1726 0 : case PG_TLS1_3_VERSION:
1727 0 : return "TLSv1.3";
1728 : }
1729 :
1730 0 : return "(unrecognized)";
1731 : }
1732 :
1733 :
1734 : static void
1735 46 : default_openssl_tls_init(SSL_CTX *context, bool isServerStart)
1736 : {
1737 46 : if (isServerStart)
1738 : {
1739 46 : if (ssl_passphrase_command[0])
1740 8 : SSL_CTX_set_default_passwd_cb(context, ssl_external_passwd_cb);
1741 : }
1742 : else
1743 : {
1744 0 : if (ssl_passphrase_command[0] && ssl_passphrase_command_supports_reload)
1745 0 : SSL_CTX_set_default_passwd_cb(context, ssl_external_passwd_cb);
1746 : else
1747 :
1748 : /*
1749 : * If reloading and no external command is configured, override
1750 : * OpenSSL's default handling of passphrase-protected files,
1751 : * because we don't want to prompt for a passphrase in an
1752 : * already-running server.
1753 : */
1754 0 : SSL_CTX_set_default_passwd_cb(context, dummy_ssl_passwd_cb);
1755 : }
1756 46 : }
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