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) 1996-2026, 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 "utils/guc.h"
37 : #include "utils/memutils.h"
38 :
39 : /*
40 : * These SSL-related #includes must come after all system-provided headers.
41 : * This ensures that OpenSSL can take care of conflicts with Windows'
42 : * <wincrypt.h> by #undef'ing the conflicting macros. (We don't directly
43 : * include <wincrypt.h>, but some other Windows headers do.)
44 : */
45 : #include "common/openssl.h"
46 : #include <openssl/bn.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 port_bio_read(BIO *h, char *buf, int size);
60 : static int port_bio_write(BIO *h, const char *buf, int size);
61 : static BIO_METHOD *port_bio_method(void);
62 : static int ssl_set_port_bio(Port *port);
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 *SSLerrmessageExt(unsigned long ecode, const char *replacement);
79 : static const char *SSLerrmessage(unsigned long ecode);
80 :
81 : static char *X509_NAME_to_cstring(X509_NAME *name);
82 :
83 : static SSL_CTX *SSL_context = NULL;
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 : struct CallbackErr
91 : {
92 : /*
93 : * Storage for passing certificate verification error logging from the
94 : * callback.
95 : */
96 : char *cert_errdetail;
97 : };
98 :
99 : /* ------------------------------------------------------------ */
100 : /* Public interface */
101 : /* ------------------------------------------------------------ */
102 :
103 : int
104 35 : be_tls_init(bool isServerStart)
105 : {
106 : SSL_CTX *context;
107 35 : int ssl_ver_min = -1;
108 35 : int ssl_ver_max = -1;
109 :
110 : /*
111 : * Create a new SSL context into which we'll load all the configuration
112 : * settings. If we fail partway through, we can avoid memory leakage by
113 : * freeing this context; we don't install it as active until the end.
114 : *
115 : * We use SSLv23_method() because it can negotiate use of the highest
116 : * mutually supported protocol version, while alternatives like
117 : * TLSv1_2_method() permit only one specific version. Note that we don't
118 : * actually allow SSL v2 or v3, only TLS protocols (see below).
119 : */
120 35 : context = SSL_CTX_new(SSLv23_method());
121 35 : if (!context)
122 : {
123 0 : ereport(isServerStart ? FATAL : LOG,
124 : (errmsg("could not create SSL context: %s",
125 : SSLerrmessage(ERR_get_error()))));
126 0 : goto error;
127 : }
128 :
129 : /*
130 : * Disable OpenSSL's moving-write-buffer sanity check, because it causes
131 : * unnecessary failures in nonblocking send cases.
132 : */
133 35 : SSL_CTX_set_mode(context, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
134 :
135 : /*
136 : * Call init hook (usually to set password callback)
137 : */
138 35 : (*openssl_tls_init_hook) (context, isServerStart);
139 :
140 : /* used by the callback */
141 35 : ssl_is_server_start = isServerStart;
142 :
143 : /*
144 : * Load and verify server's certificate and private key
145 : */
146 35 : if (SSL_CTX_use_certificate_chain_file(context, ssl_cert_file) != 1)
147 : {
148 0 : ereport(isServerStart ? FATAL : LOG,
149 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
150 : errmsg("could not load server certificate file \"%s\": %s",
151 : ssl_cert_file, SSLerrmessage(ERR_get_error()))));
152 0 : goto error;
153 : }
154 :
155 35 : if (!check_ssl_key_file_permissions(ssl_key_file, isServerStart))
156 0 : goto error;
157 :
158 : /*
159 : * OK, try to load the private key file.
160 : */
161 35 : dummy_ssl_passwd_cb_called = false;
162 :
163 35 : if (SSL_CTX_use_PrivateKey_file(context,
164 : ssl_key_file,
165 : SSL_FILETYPE_PEM) != 1)
166 : {
167 3 : if (dummy_ssl_passwd_cb_called)
168 1 : ereport(isServerStart ? FATAL : LOG,
169 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
170 : errmsg("private key file \"%s\" cannot be reloaded because it requires a passphrase",
171 : ssl_key_file)));
172 : else
173 2 : ereport(isServerStart ? FATAL : LOG,
174 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
175 : errmsg("could not load private key file \"%s\": %s",
176 : ssl_key_file, SSLerrmessage(ERR_get_error()))));
177 1 : goto error;
178 : }
179 :
180 32 : if (SSL_CTX_check_private_key(context) != 1)
181 : {
182 0 : ereport(isServerStart ? FATAL : LOG,
183 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
184 : errmsg("check of private key failed: %s",
185 : SSLerrmessage(ERR_get_error()))));
186 0 : goto error;
187 : }
188 :
189 32 : if (ssl_min_protocol_version)
190 : {
191 32 : ssl_ver_min = ssl_protocol_version_to_openssl(ssl_min_protocol_version);
192 :
193 32 : if (ssl_ver_min == -1)
194 : {
195 0 : ereport(isServerStart ? FATAL : LOG,
196 : /*- translator: first %s is a GUC option name, second %s is its value */
197 : (errmsg("\"%s\" setting \"%s\" not supported by this build",
198 : "ssl_min_protocol_version",
199 : GetConfigOption("ssl_min_protocol_version",
200 : false, false))));
201 0 : goto error;
202 : }
203 :
204 32 : if (!SSL_CTX_set_min_proto_version(context, ssl_ver_min))
205 : {
206 0 : ereport(isServerStart ? FATAL : LOG,
207 : (errmsg("could not set minimum SSL protocol version")));
208 0 : goto error;
209 : }
210 : }
211 :
212 32 : if (ssl_max_protocol_version)
213 : {
214 1 : ssl_ver_max = ssl_protocol_version_to_openssl(ssl_max_protocol_version);
215 :
216 1 : if (ssl_ver_max == -1)
217 : {
218 0 : ereport(isServerStart ? FATAL : LOG,
219 : /*- translator: first %s is a GUC option name, second %s is its value */
220 : (errmsg("\"%s\" setting \"%s\" not supported by this build",
221 : "ssl_max_protocol_version",
222 : GetConfigOption("ssl_max_protocol_version",
223 : false, false))));
224 0 : goto error;
225 : }
226 :
227 1 : if (!SSL_CTX_set_max_proto_version(context, ssl_ver_max))
228 : {
229 0 : ereport(isServerStart ? FATAL : LOG,
230 : (errmsg("could not set maximum SSL protocol version")));
231 0 : goto error;
232 : }
233 : }
234 :
235 : /* Check compatibility of min/max protocols */
236 32 : if (ssl_min_protocol_version &&
237 : ssl_max_protocol_version)
238 : {
239 : /*
240 : * No need to check for invalid values (-1) for each protocol number
241 : * as the code above would have already generated an error.
242 : */
243 1 : if (ssl_ver_min > ssl_ver_max)
244 : {
245 1 : ereport(isServerStart ? FATAL : LOG,
246 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
247 : errmsg("could not set SSL protocol version range"),
248 : errdetail("\"%s\" cannot be higher than \"%s\"",
249 : "ssl_min_protocol_version",
250 : "ssl_max_protocol_version")));
251 0 : goto error;
252 : }
253 : }
254 :
255 : /*
256 : * Disallow SSL session tickets. OpenSSL use both stateful and stateless
257 : * tickets for TLSv1.3, and stateless ticket for TLSv1.2. SSL_OP_NO_TICKET
258 : * is available since 0.9.8f but only turns off stateless tickets. In
259 : * order to turn off stateful tickets we need SSL_CTX_set_num_tickets,
260 : * which is available since OpenSSL 1.1.1. LibreSSL 3.5.4 (from OpenBSD
261 : * 7.1) introduced this API for compatibility, but doesn't support session
262 : * tickets at all so it's a no-op there.
263 : */
264 : #ifdef HAVE_SSL_CTX_SET_NUM_TICKETS
265 31 : SSL_CTX_set_num_tickets(context, 0);
266 : #endif
267 31 : SSL_CTX_set_options(context, SSL_OP_NO_TICKET);
268 :
269 : /* disallow SSL session caching, too */
270 31 : SSL_CTX_set_session_cache_mode(context, SSL_SESS_CACHE_OFF);
271 :
272 : /* disallow SSL compression */
273 31 : SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
274 :
275 : /*
276 : * Disallow SSL renegotiation. This concerns only TLSv1.2 and older
277 : * protocol versions, as TLSv1.3 has no support for renegotiation.
278 : * SSL_OP_NO_RENEGOTIATION is available in OpenSSL since 1.1.0h (via a
279 : * backport from 1.1.1). SSL_OP_NO_CLIENT_RENEGOTIATION is available in
280 : * LibreSSL since 2.5.1 disallowing all client-initiated renegotiation
281 : * (this is usually on by default).
282 : */
283 : #ifdef SSL_OP_NO_RENEGOTIATION
284 31 : SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
285 : #endif
286 : #ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
287 : SSL_CTX_set_options(context, SSL_OP_NO_CLIENT_RENEGOTIATION);
288 : #endif
289 :
290 : /* set up ephemeral DH and ECDH keys */
291 31 : if (!initialize_dh(context, isServerStart))
292 0 : goto error;
293 31 : if (!initialize_ecdh(context, isServerStart))
294 0 : goto error;
295 :
296 : /* set up the allowed cipher list for TLSv1.2 and below */
297 29 : if (SSL_CTX_set_cipher_list(context, SSLCipherList) != 1)
298 : {
299 0 : ereport(isServerStart ? FATAL : LOG,
300 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
301 : errmsg("could not set the TLSv1.2 cipher list (no valid ciphers available)")));
302 0 : goto error;
303 : }
304 :
305 : /*
306 : * Set up the allowed cipher suites for TLSv1.3. If the GUC is an empty
307 : * string we leave the allowed suites to be the OpenSSL default value.
308 : */
309 29 : if (SSLCipherSuites[0])
310 : {
311 : /* set up the allowed cipher suites */
312 23 : if (SSL_CTX_set_ciphersuites(context, SSLCipherSuites) != 1)
313 : {
314 0 : ereport(isServerStart ? FATAL : LOG,
315 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
316 : errmsg("could not set the TLSv1.3 cipher suites (no valid ciphers available)")));
317 0 : goto error;
318 : }
319 : }
320 :
321 : /* Let server choose order */
322 29 : if (SSLPreferServerCiphers)
323 29 : SSL_CTX_set_options(context, SSL_OP_CIPHER_SERVER_PREFERENCE);
324 :
325 : /*
326 : * Load CA store, so we can verify client certificates if needed.
327 : */
328 29 : if (ssl_ca_file[0])
329 : {
330 : STACK_OF(X509_NAME) * root_cert_list;
331 :
332 46 : if (SSL_CTX_load_verify_locations(context, ssl_ca_file, NULL) != 1 ||
333 23 : (root_cert_list = SSL_load_client_CA_file(ssl_ca_file)) == NULL)
334 : {
335 0 : ereport(isServerStart ? FATAL : LOG,
336 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
337 : errmsg("could not load root certificate file \"%s\": %s",
338 : ssl_ca_file, SSLerrmessage(ERR_get_error()))));
339 0 : goto error;
340 : }
341 :
342 : /*
343 : * Tell OpenSSL to send the list of root certs we trust to clients in
344 : * CertificateRequests. This lets a client with a keystore select the
345 : * appropriate client certificate to send to us. Also, this ensures
346 : * that the SSL context will "own" the root_cert_list and remember to
347 : * free it when no longer needed.
348 : */
349 23 : SSL_CTX_set_client_CA_list(context, root_cert_list);
350 :
351 : /*
352 : * Always ask for SSL client cert, but don't fail if it's not
353 : * presented. We might fail such connections later, depending on what
354 : * we find in pg_hba.conf.
355 : */
356 23 : SSL_CTX_set_verify(context,
357 : (SSL_VERIFY_PEER |
358 : SSL_VERIFY_CLIENT_ONCE),
359 : verify_cb);
360 : }
361 :
362 : /*----------
363 : * Load the Certificate Revocation List (CRL).
364 : * http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci803160,00.html
365 : *----------
366 : */
367 29 : if (ssl_crl_file[0] || ssl_crl_dir[0])
368 : {
369 23 : X509_STORE *cvstore = SSL_CTX_get_cert_store(context);
370 :
371 23 : if (cvstore)
372 : {
373 : /* Set the flags to check against the complete CRL chain */
374 46 : if (X509_STORE_load_locations(cvstore,
375 23 : ssl_crl_file[0] ? ssl_crl_file : NULL,
376 23 : ssl_crl_dir[0] ? ssl_crl_dir : NULL)
377 : == 1)
378 : {
379 23 : X509_STORE_set_flags(cvstore,
380 : X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL);
381 : }
382 0 : else if (ssl_crl_dir[0] == 0)
383 : {
384 0 : ereport(isServerStart ? FATAL : LOG,
385 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
386 : errmsg("could not load SSL certificate revocation list file \"%s\": %s",
387 : ssl_crl_file, SSLerrmessage(ERR_get_error()))));
388 0 : goto error;
389 : }
390 0 : else if (ssl_crl_file[0] == 0)
391 : {
392 0 : ereport(isServerStart ? FATAL : LOG,
393 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
394 : errmsg("could not load SSL certificate revocation list directory \"%s\": %s",
395 : ssl_crl_dir, SSLerrmessage(ERR_get_error()))));
396 0 : goto error;
397 : }
398 : else
399 : {
400 0 : ereport(isServerStart ? FATAL : LOG,
401 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
402 : errmsg("could not load SSL certificate revocation list file \"%s\" or directory \"%s\": %s",
403 : ssl_crl_file, ssl_crl_dir,
404 : SSLerrmessage(ERR_get_error()))));
405 0 : goto error;
406 : }
407 : }
408 : }
409 :
410 : /*
411 : * Success! Replace any existing SSL_context.
412 : */
413 29 : if (SSL_context)
414 1 : SSL_CTX_free(SSL_context);
415 :
416 29 : SSL_context = context;
417 :
418 : /*
419 : * Set flag to remember whether CA store has been loaded into SSL_context.
420 : */
421 29 : if (ssl_ca_file[0])
422 23 : ssl_loaded_verify_locations = true;
423 : else
424 6 : ssl_loaded_verify_locations = false;
425 :
426 29 : return 0;
427 :
428 : /* Clean up by releasing working context. */
429 1 : error:
430 1 : if (context)
431 1 : SSL_CTX_free(context);
432 1 : return -1;
433 : }
434 :
435 : void
436 147 : be_tls_destroy(void)
437 : {
438 147 : if (SSL_context)
439 1 : SSL_CTX_free(SSL_context);
440 147 : SSL_context = NULL;
441 147 : ssl_loaded_verify_locations = false;
442 147 : }
443 :
444 : int
445 129 : be_tls_open_server(Port *port)
446 : {
447 : int r;
448 : int err;
449 : int waitfor;
450 : unsigned long ecode;
451 : bool give_proto_hint;
452 : static struct CallbackErr err_context;
453 :
454 : Assert(!port->ssl);
455 : Assert(!port->peer);
456 :
457 129 : if (!SSL_context)
458 : {
459 0 : ereport(COMMERROR,
460 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
461 : errmsg("could not initialize SSL connection: SSL context not set up")));
462 0 : return -1;
463 : }
464 :
465 : /* set up debugging/info callback */
466 129 : SSL_CTX_set_info_callback(SSL_context, info_cb);
467 :
468 : /* enable ALPN */
469 129 : SSL_CTX_set_alpn_select_cb(SSL_context, alpn_cb, port);
470 :
471 129 : if (!(port->ssl = SSL_new(SSL_context)))
472 : {
473 0 : ereport(COMMERROR,
474 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
475 : errmsg("could not initialize SSL connection: %s",
476 : SSLerrmessage(ERR_get_error()))));
477 0 : return -1;
478 : }
479 129 : if (!ssl_set_port_bio(port))
480 : {
481 0 : ereport(COMMERROR,
482 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
483 : errmsg("could not set SSL socket: %s",
484 : SSLerrmessage(ERR_get_error()))));
485 0 : return -1;
486 : }
487 :
488 129 : err_context.cert_errdetail = NULL;
489 129 : SSL_set_ex_data(port->ssl, 0, &err_context);
490 :
491 129 : port->ssl_in_use = true;
492 :
493 438 : aloop:
494 :
495 : /*
496 : * Prepare to call SSL_get_error() by clearing thread's OpenSSL error
497 : * queue. In general, the current thread's error queue must be empty
498 : * before the TLS/SSL I/O operation is attempted, or SSL_get_error() will
499 : * not work reliably. An extension may have failed to clear the
500 : * per-thread error queue following another call to an OpenSSL I/O
501 : * routine.
502 : */
503 438 : errno = 0;
504 438 : ERR_clear_error();
505 438 : r = SSL_accept(port->ssl);
506 438 : if (r <= 0)
507 : {
508 328 : err = SSL_get_error(port->ssl, r);
509 :
510 : /*
511 : * Other clients of OpenSSL in the backend may fail to call
512 : * ERR_get_error(), but we always do, so as to not cause problems for
513 : * OpenSSL clients that don't call ERR_clear_error() defensively. Be
514 : * sure that this happens by calling now. SSL_get_error() relies on
515 : * the OpenSSL per-thread error queue being intact, so this is the
516 : * earliest possible point ERR_get_error() may be called.
517 : */
518 328 : ecode = ERR_get_error();
519 328 : switch (err)
520 : {
521 309 : case SSL_ERROR_WANT_READ:
522 : case SSL_ERROR_WANT_WRITE:
523 : /* not allowed during connection establishment */
524 : Assert(!port->noblock);
525 :
526 : /*
527 : * No need to care about timeouts/interrupts here. At this
528 : * point authentication_timeout still employs
529 : * StartupPacketTimeoutHandler() which directly exits.
530 : */
531 309 : if (err == SSL_ERROR_WANT_READ)
532 309 : waitfor = WL_SOCKET_READABLE | WL_EXIT_ON_PM_DEATH;
533 : else
534 0 : waitfor = WL_SOCKET_WRITEABLE | WL_EXIT_ON_PM_DEATH;
535 :
536 309 : (void) WaitLatchOrSocket(NULL, waitfor, port->sock, 0,
537 : WAIT_EVENT_SSL_OPEN_SERVER);
538 309 : goto aloop;
539 0 : case SSL_ERROR_SYSCALL:
540 0 : if (r < 0 && errno != 0)
541 0 : ereport(COMMERROR,
542 : (errcode_for_socket_access(),
543 : errmsg("could not accept SSL connection: %m")));
544 : else
545 0 : ereport(COMMERROR,
546 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
547 : errmsg("could not accept SSL connection: EOF detected")));
548 0 : break;
549 19 : case SSL_ERROR_SSL:
550 19 : switch (ERR_GET_REASON(ecode))
551 : {
552 : /*
553 : * UNSUPPORTED_PROTOCOL, WRONG_VERSION_NUMBER, and
554 : * TLSV1_ALERT_PROTOCOL_VERSION have been observed
555 : * when trying to communicate with an old OpenSSL
556 : * library, or when the client and server specify
557 : * disjoint protocol ranges. NO_PROTOCOLS_AVAILABLE
558 : * occurs if there's a local misconfiguration (which
559 : * can happen despite our checks, if openssl.cnf
560 : * injects a limit we didn't account for). It's not
561 : * very clear what would make OpenSSL return the other
562 : * codes listed here, but a hint about protocol
563 : * versions seems like it's appropriate for all.
564 : */
565 0 : case SSL_R_NO_PROTOCOLS_AVAILABLE:
566 : case SSL_R_UNSUPPORTED_PROTOCOL:
567 : case SSL_R_BAD_PROTOCOL_VERSION_NUMBER:
568 : case SSL_R_UNKNOWN_PROTOCOL:
569 : case SSL_R_UNKNOWN_SSL_VERSION:
570 : case SSL_R_UNSUPPORTED_SSL_VERSION:
571 : case SSL_R_WRONG_SSL_VERSION:
572 : case SSL_R_WRONG_VERSION_NUMBER:
573 : case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
574 : #ifdef SSL_R_VERSION_TOO_HIGH
575 : case SSL_R_VERSION_TOO_HIGH:
576 : #endif
577 : #ifdef SSL_R_VERSION_TOO_LOW
578 : case SSL_R_VERSION_TOO_LOW:
579 : #endif
580 0 : give_proto_hint = true;
581 0 : break;
582 19 : default:
583 19 : give_proto_hint = false;
584 19 : break;
585 : }
586 19 : ereport(COMMERROR,
587 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
588 : errmsg("could not accept SSL connection: %s",
589 : SSLerrmessage(ecode)),
590 : err_context.cert_errdetail ? errdetail_internal("%s", err_context.cert_errdetail) : 0,
591 : give_proto_hint ?
592 : errhint("This may indicate that the client does not support any SSL protocol version between %s and %s.",
593 : ssl_min_protocol_version ?
594 : ssl_protocol_version_to_string(ssl_min_protocol_version) :
595 : MIN_OPENSSL_TLS_VERSION,
596 : ssl_max_protocol_version ?
597 : ssl_protocol_version_to_string(ssl_max_protocol_version) :
598 : MAX_OPENSSL_TLS_VERSION) : 0));
599 19 : if (err_context.cert_errdetail)
600 6 : pfree(err_context.cert_errdetail);
601 19 : break;
602 0 : case SSL_ERROR_ZERO_RETURN:
603 0 : ereport(COMMERROR,
604 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
605 : errmsg("could not accept SSL connection: EOF detected")));
606 0 : break;
607 0 : default:
608 0 : ereport(COMMERROR,
609 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
610 : errmsg("unrecognized SSL error code: %d",
611 : err)));
612 0 : break;
613 : }
614 19 : return -1;
615 : }
616 :
617 : /* Get the protocol selected by ALPN */
618 110 : port->alpn_used = false;
619 : {
620 : const unsigned char *selected;
621 : unsigned int len;
622 :
623 110 : SSL_get0_alpn_selected(port->ssl, &selected, &len);
624 :
625 : /* If ALPN is used, check that we negotiated the expected protocol */
626 110 : if (selected != NULL)
627 : {
628 110 : if (len == strlen(PG_ALPN_PROTOCOL) &&
629 110 : memcmp(selected, PG_ALPN_PROTOCOL, strlen(PG_ALPN_PROTOCOL)) == 0)
630 : {
631 110 : port->alpn_used = true;
632 : }
633 : else
634 : {
635 : /* shouldn't happen */
636 0 : ereport(COMMERROR,
637 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
638 : errmsg("received SSL connection request with unexpected ALPN protocol")));
639 : }
640 : }
641 : }
642 :
643 : /* Get client certificate, if available. */
644 110 : port->peer = SSL_get_peer_certificate(port->ssl);
645 :
646 : /* and extract the Common Name and Distinguished Name from it. */
647 110 : port->peer_cn = NULL;
648 110 : port->peer_dn = NULL;
649 110 : port->peer_cert_valid = false;
650 110 : if (port->peer != NULL)
651 : {
652 : int len;
653 29 : X509_NAME *x509name = X509_get_subject_name(port->peer);
654 : char *peer_dn;
655 29 : BIO *bio = NULL;
656 29 : BUF_MEM *bio_buf = NULL;
657 :
658 29 : len = X509_NAME_get_text_by_NID(x509name, NID_commonName, NULL, 0);
659 29 : if (len != -1)
660 : {
661 : char *peer_cn;
662 :
663 29 : peer_cn = MemoryContextAlloc(TopMemoryContext, len + 1);
664 29 : r = X509_NAME_get_text_by_NID(x509name, NID_commonName, peer_cn,
665 : len + 1);
666 29 : peer_cn[len] = '\0';
667 29 : if (r != len)
668 : {
669 : /* shouldn't happen */
670 0 : pfree(peer_cn);
671 0 : return -1;
672 : }
673 :
674 : /*
675 : * Reject embedded NULLs in certificate common name to prevent
676 : * attacks like CVE-2009-4034.
677 : */
678 29 : if (len != strlen(peer_cn))
679 : {
680 0 : ereport(COMMERROR,
681 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
682 : errmsg("SSL certificate's common name contains embedded null")));
683 0 : pfree(peer_cn);
684 0 : return -1;
685 : }
686 :
687 29 : port->peer_cn = peer_cn;
688 : }
689 :
690 29 : bio = BIO_new(BIO_s_mem());
691 29 : if (!bio)
692 : {
693 0 : if (port->peer_cn != NULL)
694 : {
695 0 : pfree(port->peer_cn);
696 0 : port->peer_cn = NULL;
697 : }
698 0 : return -1;
699 : }
700 :
701 : /*
702 : * RFC2253 is the closest thing to an accepted standard format for
703 : * DNs. We have documented how to produce this format from a
704 : * certificate. It uses commas instead of slashes for delimiters,
705 : * which make regular expression matching a bit easier. Also note that
706 : * it prints the Subject fields in reverse order.
707 : */
708 58 : if (X509_NAME_print_ex(bio, x509name, 0, XN_FLAG_RFC2253) == -1 ||
709 29 : BIO_get_mem_ptr(bio, &bio_buf) <= 0)
710 : {
711 0 : BIO_free(bio);
712 0 : if (port->peer_cn != NULL)
713 : {
714 0 : pfree(port->peer_cn);
715 0 : port->peer_cn = NULL;
716 : }
717 0 : return -1;
718 : }
719 29 : peer_dn = MemoryContextAlloc(TopMemoryContext, bio_buf->length + 1);
720 29 : memcpy(peer_dn, bio_buf->data, bio_buf->length);
721 29 : len = bio_buf->length;
722 29 : BIO_free(bio);
723 29 : peer_dn[len] = '\0';
724 29 : if (len != strlen(peer_dn))
725 : {
726 0 : ereport(COMMERROR,
727 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
728 : errmsg("SSL certificate's distinguished name contains embedded null")));
729 0 : pfree(peer_dn);
730 0 : if (port->peer_cn != NULL)
731 : {
732 0 : pfree(port->peer_cn);
733 0 : port->peer_cn = NULL;
734 : }
735 0 : return -1;
736 : }
737 :
738 29 : port->peer_dn = peer_dn;
739 :
740 29 : port->peer_cert_valid = true;
741 : }
742 :
743 110 : return 0;
744 : }
745 :
746 : void
747 129 : be_tls_close(Port *port)
748 : {
749 129 : if (port->ssl)
750 : {
751 129 : SSL_shutdown(port->ssl);
752 129 : SSL_free(port->ssl);
753 129 : port->ssl = NULL;
754 129 : port->ssl_in_use = false;
755 : }
756 :
757 129 : if (port->peer)
758 : {
759 29 : X509_free(port->peer);
760 29 : port->peer = NULL;
761 : }
762 :
763 129 : if (port->peer_cn)
764 : {
765 29 : pfree(port->peer_cn);
766 29 : port->peer_cn = NULL;
767 : }
768 :
769 129 : if (port->peer_dn)
770 : {
771 29 : pfree(port->peer_dn);
772 29 : port->peer_dn = NULL;
773 : }
774 129 : }
775 :
776 : ssize_t
777 480 : be_tls_read(Port *port, void *ptr, size_t len, int *waitfor)
778 : {
779 : ssize_t n;
780 : int err;
781 : unsigned long ecode;
782 :
783 480 : errno = 0;
784 480 : ERR_clear_error();
785 480 : n = SSL_read(port->ssl, ptr, len);
786 480 : err = SSL_get_error(port->ssl, n);
787 480 : ecode = (err != SSL_ERROR_NONE || n < 0) ? ERR_get_error() : 0;
788 480 : switch (err)
789 : {
790 281 : case SSL_ERROR_NONE:
791 : /* a-ok */
792 281 : break;
793 182 : case SSL_ERROR_WANT_READ:
794 182 : *waitfor = WL_SOCKET_READABLE;
795 182 : errno = EWOULDBLOCK;
796 182 : n = -1;
797 182 : break;
798 0 : case SSL_ERROR_WANT_WRITE:
799 0 : *waitfor = WL_SOCKET_WRITEABLE;
800 0 : errno = EWOULDBLOCK;
801 0 : n = -1;
802 0 : break;
803 0 : case SSL_ERROR_SYSCALL:
804 : /* leave it to caller to ereport the value of errno */
805 0 : if (n != -1 || errno == 0)
806 : {
807 0 : errno = ECONNRESET;
808 0 : n = -1;
809 : }
810 0 : break;
811 0 : case SSL_ERROR_SSL:
812 0 : ereport(COMMERROR,
813 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
814 : errmsg("SSL error: %s", SSLerrmessage(ecode))));
815 0 : errno = ECONNRESET;
816 0 : n = -1;
817 0 : break;
818 17 : case SSL_ERROR_ZERO_RETURN:
819 : /* connection was cleanly shut down by peer */
820 17 : n = 0;
821 17 : break;
822 0 : default:
823 0 : ereport(COMMERROR,
824 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
825 : errmsg("unrecognized SSL error code: %d",
826 : err)));
827 0 : errno = ECONNRESET;
828 0 : n = -1;
829 0 : break;
830 : }
831 :
832 480 : return n;
833 : }
834 :
835 : ssize_t
836 196 : be_tls_write(Port *port, const void *ptr, size_t len, int *waitfor)
837 : {
838 : ssize_t n;
839 : int err;
840 : unsigned long ecode;
841 :
842 196 : errno = 0;
843 196 : ERR_clear_error();
844 196 : n = SSL_write(port->ssl, ptr, len);
845 196 : err = SSL_get_error(port->ssl, n);
846 196 : ecode = (err != SSL_ERROR_NONE || n < 0) ? ERR_get_error() : 0;
847 196 : switch (err)
848 : {
849 196 : case SSL_ERROR_NONE:
850 : /* a-ok */
851 196 : break;
852 0 : case SSL_ERROR_WANT_READ:
853 0 : *waitfor = WL_SOCKET_READABLE;
854 0 : errno = EWOULDBLOCK;
855 0 : n = -1;
856 0 : break;
857 0 : case SSL_ERROR_WANT_WRITE:
858 0 : *waitfor = WL_SOCKET_WRITEABLE;
859 0 : errno = EWOULDBLOCK;
860 0 : n = -1;
861 0 : break;
862 0 : case SSL_ERROR_SYSCALL:
863 :
864 : /*
865 : * Leave it to caller to ereport the value of errno. However, if
866 : * errno is still zero then assume it's a read EOF situation, and
867 : * report ECONNRESET. (This seems possible because SSL_write can
868 : * also do reads.)
869 : */
870 0 : if (n != -1 || errno == 0)
871 : {
872 0 : errno = ECONNRESET;
873 0 : n = -1;
874 : }
875 0 : break;
876 0 : case SSL_ERROR_SSL:
877 0 : ereport(COMMERROR,
878 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
879 : errmsg("SSL error: %s", SSLerrmessage(ecode))));
880 0 : errno = ECONNRESET;
881 0 : n = -1;
882 0 : break;
883 0 : case SSL_ERROR_ZERO_RETURN:
884 :
885 : /*
886 : * the SSL connection was closed, leave it to the caller to
887 : * ereport it
888 : */
889 0 : errno = ECONNRESET;
890 0 : n = -1;
891 0 : break;
892 0 : default:
893 0 : ereport(COMMERROR,
894 : (errcode(ERRCODE_PROTOCOL_VIOLATION),
895 : errmsg("unrecognized SSL error code: %d",
896 : err)));
897 0 : errno = ECONNRESET;
898 0 : n = -1;
899 0 : break;
900 : }
901 :
902 196 : return n;
903 : }
904 :
905 : /* ------------------------------------------------------------ */
906 : /* Internal functions */
907 : /* ------------------------------------------------------------ */
908 :
909 : /*
910 : * Private substitute BIO: this does the sending and receiving using send() and
911 : * recv() instead. This is so that we can enable and disable interrupts
912 : * just while calling recv(). We cannot have interrupts occurring while
913 : * the bulk of OpenSSL runs, because it uses malloc() and possibly other
914 : * non-reentrant libc facilities. We also need to call send() and recv()
915 : * directly so it gets passed through the socket/signals layer on Win32.
916 : *
917 : * These functions are closely modelled on the standard socket BIO in OpenSSL;
918 : * see sock_read() and sock_write() in OpenSSL's crypto/bio/bss_sock.c.
919 : */
920 :
921 : static BIO_METHOD *port_bio_method_ptr = NULL;
922 :
923 : static int
924 2329 : port_bio_read(BIO *h, char *buf, int size)
925 : {
926 2329 : int res = 0;
927 2329 : Port *port = (Port *) BIO_get_data(h);
928 :
929 2329 : if (buf != NULL)
930 : {
931 2329 : res = secure_raw_read(port, buf, size);
932 2329 : BIO_clear_retry_flags(h);
933 2329 : port->last_read_was_eof = res == 0;
934 2329 : if (res <= 0)
935 : {
936 : /* If we were interrupted, tell caller to retry */
937 495 : if (errno == EINTR || errno == EWOULDBLOCK || errno == EAGAIN)
938 : {
939 491 : BIO_set_retry_read(h);
940 : }
941 : }
942 : }
943 :
944 2329 : return res;
945 : }
946 :
947 : static int
948 556 : port_bio_write(BIO *h, const char *buf, int size)
949 : {
950 556 : int res = 0;
951 :
952 556 : res = secure_raw_write(((Port *) BIO_get_data(h)), buf, size);
953 556 : BIO_clear_retry_flags(h);
954 556 : if (res <= 0)
955 : {
956 : /* If we were interrupted, tell caller to retry */
957 0 : if (errno == EINTR || errno == EWOULDBLOCK || errno == EAGAIN)
958 : {
959 0 : BIO_set_retry_write(h);
960 : }
961 : }
962 :
963 556 : return res;
964 : }
965 :
966 : static long
967 622 : port_bio_ctrl(BIO *h, int cmd, long num, void *ptr)
968 : {
969 : long res;
970 622 : Port *port = (Port *) BIO_get_data(h);
971 :
972 622 : switch (cmd)
973 : {
974 4 : case BIO_CTRL_EOF:
975 :
976 : /*
977 : * This should not be needed. port_bio_read already has a way to
978 : * signal EOF to OpenSSL. However, OpenSSL made an undocumented,
979 : * backwards-incompatible change and now expects EOF via BIO_ctrl.
980 : * See https://github.com/openssl/openssl/issues/8208
981 : */
982 4 : res = port->last_read_was_eof;
983 4 : break;
984 360 : case BIO_CTRL_FLUSH:
985 : /* libssl expects all BIOs to support BIO_flush. */
986 360 : res = 1;
987 360 : break;
988 258 : default:
989 258 : res = 0;
990 258 : break;
991 : }
992 :
993 622 : return res;
994 : }
995 :
996 : static BIO_METHOD *
997 129 : port_bio_method(void)
998 : {
999 129 : if (!port_bio_method_ptr)
1000 : {
1001 : int my_bio_index;
1002 :
1003 129 : my_bio_index = BIO_get_new_index();
1004 129 : if (my_bio_index == -1)
1005 0 : return NULL;
1006 129 : my_bio_index |= BIO_TYPE_SOURCE_SINK;
1007 129 : port_bio_method_ptr = BIO_meth_new(my_bio_index, "PostgreSQL backend socket");
1008 129 : if (!port_bio_method_ptr)
1009 0 : return NULL;
1010 258 : if (!BIO_meth_set_write(port_bio_method_ptr, port_bio_write) ||
1011 258 : !BIO_meth_set_read(port_bio_method_ptr, port_bio_read) ||
1012 129 : !BIO_meth_set_ctrl(port_bio_method_ptr, port_bio_ctrl))
1013 : {
1014 0 : BIO_meth_free(port_bio_method_ptr);
1015 0 : port_bio_method_ptr = NULL;
1016 0 : return NULL;
1017 : }
1018 : }
1019 129 : return port_bio_method_ptr;
1020 : }
1021 :
1022 : static int
1023 129 : ssl_set_port_bio(Port *port)
1024 : {
1025 : BIO *bio;
1026 : BIO_METHOD *bio_method;
1027 :
1028 129 : bio_method = port_bio_method();
1029 129 : if (bio_method == NULL)
1030 0 : return 0;
1031 :
1032 129 : bio = BIO_new(bio_method);
1033 129 : if (bio == NULL)
1034 0 : return 0;
1035 :
1036 129 : BIO_set_data(bio, port);
1037 129 : BIO_set_init(bio, 1);
1038 :
1039 129 : SSL_set_bio(port->ssl, bio, bio);
1040 129 : return 1;
1041 : }
1042 :
1043 : /*
1044 : * Load precomputed DH parameters.
1045 : *
1046 : * To prevent "downgrade" attacks, we perform a number of checks
1047 : * to verify that the DBA-generated DH parameters file contains
1048 : * what we expect it to contain.
1049 : */
1050 : static DH *
1051 0 : load_dh_file(char *filename, bool isServerStart)
1052 : {
1053 : FILE *fp;
1054 0 : DH *dh = NULL;
1055 : int codes;
1056 :
1057 : /* attempt to open file. It's not an error if it doesn't exist. */
1058 0 : if ((fp = AllocateFile(filename, "r")) == NULL)
1059 : {
1060 0 : ereport(isServerStart ? FATAL : LOG,
1061 : (errcode_for_file_access(),
1062 : errmsg("could not open DH parameters file \"%s\": %m",
1063 : filename)));
1064 0 : return NULL;
1065 : }
1066 :
1067 0 : dh = PEM_read_DHparams(fp, NULL, NULL, NULL);
1068 0 : FreeFile(fp);
1069 :
1070 0 : if (dh == NULL)
1071 : {
1072 0 : ereport(isServerStart ? FATAL : LOG,
1073 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1074 : errmsg("could not load DH parameters file: %s",
1075 : SSLerrmessage(ERR_get_error()))));
1076 0 : return NULL;
1077 : }
1078 :
1079 : /* make sure the DH parameters are usable */
1080 0 : if (DH_check(dh, &codes) == 0)
1081 : {
1082 0 : ereport(isServerStart ? FATAL : LOG,
1083 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1084 : errmsg("invalid DH parameters: %s",
1085 : SSLerrmessage(ERR_get_error()))));
1086 0 : DH_free(dh);
1087 0 : return NULL;
1088 : }
1089 0 : if (codes & DH_CHECK_P_NOT_PRIME)
1090 : {
1091 0 : ereport(isServerStart ? FATAL : LOG,
1092 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1093 : errmsg("invalid DH parameters: p is not prime")));
1094 0 : DH_free(dh);
1095 0 : return NULL;
1096 : }
1097 0 : if ((codes & DH_NOT_SUITABLE_GENERATOR) &&
1098 0 : (codes & DH_CHECK_P_NOT_SAFE_PRIME))
1099 : {
1100 0 : ereport(isServerStart ? FATAL : LOG,
1101 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1102 : errmsg("invalid DH parameters: neither suitable generator or safe prime")));
1103 0 : DH_free(dh);
1104 0 : return NULL;
1105 : }
1106 :
1107 0 : return dh;
1108 : }
1109 :
1110 : /*
1111 : * Load hardcoded DH parameters.
1112 : *
1113 : * If DH parameters cannot be loaded from a specified file, we can load
1114 : * the hardcoded DH parameters supplied with the backend to prevent
1115 : * problems.
1116 : */
1117 : static DH *
1118 31 : load_dh_buffer(const char *buffer, size_t len)
1119 : {
1120 : BIO *bio;
1121 31 : DH *dh = NULL;
1122 :
1123 31 : bio = BIO_new_mem_buf(buffer, len);
1124 31 : if (bio == NULL)
1125 0 : return NULL;
1126 31 : dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
1127 31 : if (dh == NULL)
1128 0 : ereport(DEBUG2,
1129 : (errmsg_internal("DH load buffer: %s",
1130 : SSLerrmessage(ERR_get_error()))));
1131 31 : BIO_free(bio);
1132 :
1133 31 : return dh;
1134 : }
1135 :
1136 : /*
1137 : * Passphrase collection callback using ssl_passphrase_command
1138 : */
1139 : static int
1140 8 : ssl_external_passwd_cb(char *buf, int size, int rwflag, void *userdata)
1141 : {
1142 : /* same prompt as OpenSSL uses internally */
1143 8 : const char *prompt = "Enter PEM pass phrase:";
1144 :
1145 : Assert(rwflag == 0);
1146 :
1147 8 : return run_ssl_passphrase_command(prompt, ssl_is_server_start, buf, size);
1148 : }
1149 :
1150 : /*
1151 : * Dummy passphrase callback
1152 : *
1153 : * If OpenSSL is told to use a passphrase-protected server key, by default
1154 : * it will issue a prompt on /dev/tty and try to read a key from there.
1155 : * That's no good during a postmaster SIGHUP cycle, not to mention SSL context
1156 : * reload in an EXEC_BACKEND postmaster child. So override it with this dummy
1157 : * function that just returns an empty passphrase, guaranteeing failure.
1158 : */
1159 : static int
1160 1 : dummy_ssl_passwd_cb(char *buf, int size, int rwflag, void *userdata)
1161 : {
1162 : /* Set flag to change the error message we'll report */
1163 1 : dummy_ssl_passwd_cb_called = true;
1164 : /* And return empty string */
1165 : Assert(size > 0);
1166 1 : buf[0] = '\0';
1167 1 : return 0;
1168 : }
1169 :
1170 : /*
1171 : * Examines the provided certificate name, and if it's too long to log or
1172 : * contains unprintable ASCII, escapes and truncates it. The return value is
1173 : * always a new palloc'd string. (The input string is still modified in place,
1174 : * for ease of implementation.)
1175 : */
1176 : static char *
1177 12 : prepare_cert_name(char *name)
1178 : {
1179 12 : size_t namelen = strlen(name);
1180 12 : char *truncated = name;
1181 :
1182 : /*
1183 : * Common Names are 64 chars max, so for a common case where the CN is the
1184 : * last field, we can still print the longest possible CN with a
1185 : * 7-character prefix (".../CN=[64 chars]"), for a reasonable limit of 71
1186 : * characters.
1187 : */
1188 : #define MAXLEN 71
1189 :
1190 12 : if (namelen > MAXLEN)
1191 : {
1192 : /*
1193 : * Keep the end of the name, not the beginning, since the most
1194 : * specific field is likely to give users the most information.
1195 : */
1196 1 : truncated = name + namelen - MAXLEN;
1197 1 : truncated[0] = truncated[1] = truncated[2] = '.';
1198 1 : namelen = MAXLEN;
1199 : }
1200 :
1201 : #undef MAXLEN
1202 :
1203 12 : return pg_clean_ascii(truncated, 0);
1204 : }
1205 :
1206 : /*
1207 : * Certificate verification callback
1208 : *
1209 : * This callback allows us to examine intermediate problems during
1210 : * verification, for later logging.
1211 : *
1212 : * This callback also allows us to override the default acceptance
1213 : * criteria (e.g., accepting self-signed or expired certs), but
1214 : * for now we accept the default checks.
1215 : */
1216 : static int
1217 93 : verify_cb(int ok, X509_STORE_CTX *ctx)
1218 : {
1219 : int depth;
1220 : int errcode;
1221 : const char *errstring;
1222 : StringInfoData str;
1223 : X509 *cert;
1224 : SSL *ssl;
1225 : struct CallbackErr *cb_err;
1226 :
1227 93 : if (ok)
1228 : {
1229 : /* Nothing to do for the successful case. */
1230 87 : return ok;
1231 : }
1232 :
1233 : /* Pull all the information we have on the verification failure. */
1234 6 : depth = X509_STORE_CTX_get_error_depth(ctx);
1235 6 : errcode = X509_STORE_CTX_get_error(ctx);
1236 6 : errstring = X509_verify_cert_error_string(errcode);
1237 :
1238 : /*
1239 : * Extract the current SSL and CallbackErr object to use for passing error
1240 : * detail back from the callback.
1241 : */
1242 6 : ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx());
1243 6 : cb_err = (struct CallbackErr *) SSL_get_ex_data(ssl, 0);
1244 :
1245 6 : initStringInfo(&str);
1246 6 : appendStringInfo(&str,
1247 6 : _("Client certificate verification failed at depth %d: %s."),
1248 : depth, errstring);
1249 :
1250 6 : cert = X509_STORE_CTX_get_current_cert(ctx);
1251 6 : if (cert)
1252 : {
1253 : char *subject,
1254 : *issuer;
1255 : char *sub_prepared,
1256 : *iss_prepared;
1257 : char *serialno;
1258 : ASN1_INTEGER *sn;
1259 : BIGNUM *b;
1260 :
1261 : /*
1262 : * Get the Subject and Issuer for logging, but don't let maliciously
1263 : * huge certs flood the logs, and don't reflect non-ASCII bytes into
1264 : * it either.
1265 : */
1266 6 : subject = X509_NAME_to_cstring(X509_get_subject_name(cert));
1267 6 : sub_prepared = prepare_cert_name(subject);
1268 6 : pfree(subject);
1269 :
1270 6 : issuer = X509_NAME_to_cstring(X509_get_issuer_name(cert));
1271 6 : iss_prepared = prepare_cert_name(issuer);
1272 6 : pfree(issuer);
1273 :
1274 : /*
1275 : * Pull the serial number, too, in case a Subject is still ambiguous.
1276 : * This mirrors be_tls_get_peer_serial().
1277 : */
1278 6 : sn = X509_get_serialNumber(cert);
1279 6 : b = ASN1_INTEGER_to_BN(sn, NULL);
1280 6 : serialno = BN_bn2dec(b);
1281 :
1282 6 : appendStringInfoChar(&str, '\n');
1283 6 : appendStringInfo(&str,
1284 6 : _("Failed certificate data (unverified): subject \"%s\", serial number %s, issuer \"%s\"."),
1285 0 : sub_prepared, serialno ? serialno : _("unknown"),
1286 : iss_prepared);
1287 :
1288 6 : BN_free(b);
1289 6 : OPENSSL_free(serialno);
1290 6 : pfree(iss_prepared);
1291 6 : pfree(sub_prepared);
1292 : }
1293 :
1294 : /* Store our detail message to be logged later. */
1295 6 : cb_err->cert_errdetail = str.data;
1296 :
1297 6 : return ok;
1298 : }
1299 :
1300 : /*
1301 : * This callback is used to copy SSL information messages
1302 : * into the PostgreSQL log.
1303 : */
1304 : static void
1305 3001 : info_cb(const SSL *ssl, int type, int args)
1306 : {
1307 : const char *desc;
1308 :
1309 3001 : desc = SSL_state_string_long(ssl);
1310 :
1311 3001 : switch (type)
1312 : {
1313 129 : case SSL_CB_HANDSHAKE_START:
1314 129 : ereport(DEBUG4,
1315 : (errmsg_internal("SSL: handshake start: \"%s\"", desc)));
1316 129 : break;
1317 110 : case SSL_CB_HANDSHAKE_DONE:
1318 110 : ereport(DEBUG4,
1319 : (errmsg_internal("SSL: handshake done: \"%s\"", desc)));
1320 110 : break;
1321 2178 : case SSL_CB_ACCEPT_LOOP:
1322 2178 : ereport(DEBUG4,
1323 : (errmsg_internal("SSL: accept loop: \"%s\"", desc)));
1324 2178 : break;
1325 438 : case SSL_CB_ACCEPT_EXIT:
1326 438 : ereport(DEBUG4,
1327 : (errmsg_internal("SSL: accept exit (%d): \"%s\"", args, desc)));
1328 438 : break;
1329 0 : case SSL_CB_CONNECT_LOOP:
1330 0 : ereport(DEBUG4,
1331 : (errmsg_internal("SSL: connect loop: \"%s\"", desc)));
1332 0 : break;
1333 0 : case SSL_CB_CONNECT_EXIT:
1334 0 : ereport(DEBUG4,
1335 : (errmsg_internal("SSL: connect exit (%d): \"%s\"", args, desc)));
1336 0 : break;
1337 26 : case SSL_CB_READ_ALERT:
1338 26 : ereport(DEBUG4,
1339 : (errmsg_internal("SSL: read alert (0x%04x): \"%s\"", args, desc)));
1340 26 : break;
1341 120 : case SSL_CB_WRITE_ALERT:
1342 120 : ereport(DEBUG4,
1343 : (errmsg_internal("SSL: write alert (0x%04x): \"%s\"", args, desc)));
1344 120 : break;
1345 : }
1346 3001 : }
1347 :
1348 : /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
1349 : static const unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
1350 :
1351 : /*
1352 : * Server callback for ALPN negotiation. We use the standard "helper" function
1353 : * even though currently we only accept one value.
1354 : */
1355 : static int
1356 238 : alpn_cb(SSL *ssl,
1357 : const unsigned char **out,
1358 : unsigned char *outlen,
1359 : const unsigned char *in,
1360 : unsigned int inlen,
1361 : void *userdata)
1362 : {
1363 : /*
1364 : * Why does OpenSSL provide a helper function that requires a nonconst
1365 : * vector when the callback is declared to take a const vector? What are
1366 : * we to do with that?
1367 : */
1368 : int retval;
1369 :
1370 : Assert(userdata != NULL);
1371 : Assert(out != NULL);
1372 : Assert(outlen != NULL);
1373 : Assert(in != NULL);
1374 :
1375 238 : retval = SSL_select_next_proto((unsigned char **) out, outlen,
1376 : alpn_protos, sizeof(alpn_protos),
1377 : in, inlen);
1378 238 : if (*out == NULL || *outlen > sizeof(alpn_protos) || *outlen <= 0)
1379 0 : return SSL_TLSEXT_ERR_NOACK; /* can't happen */
1380 :
1381 238 : if (retval == OPENSSL_NPN_NEGOTIATED)
1382 238 : return SSL_TLSEXT_ERR_OK;
1383 : else
1384 : {
1385 : /*
1386 : * The client doesn't support our protocol. Reject the connection
1387 : * with TLS "no_application_protocol" alert, per RFC 7301.
1388 : */
1389 0 : return SSL_TLSEXT_ERR_ALERT_FATAL;
1390 : }
1391 : }
1392 :
1393 :
1394 : /*
1395 : * Set DH parameters for generating ephemeral DH keys. The
1396 : * DH parameters can take a long time to compute, so they must be
1397 : * precomputed.
1398 : *
1399 : * Since few sites will bother to create a parameter file, we also
1400 : * provide a fallback to the parameters provided by the OpenSSL
1401 : * project.
1402 : *
1403 : * These values can be static (once loaded or computed) since the
1404 : * OpenSSL library can efficiently generate random keys from the
1405 : * information provided.
1406 : */
1407 : static bool
1408 31 : initialize_dh(SSL_CTX *context, bool isServerStart)
1409 : {
1410 31 : DH *dh = NULL;
1411 :
1412 31 : SSL_CTX_set_options(context, SSL_OP_SINGLE_DH_USE);
1413 :
1414 31 : if (ssl_dh_params_file[0])
1415 0 : dh = load_dh_file(ssl_dh_params_file, isServerStart);
1416 31 : if (!dh)
1417 31 : dh = load_dh_buffer(FILE_DH2048, sizeof(FILE_DH2048));
1418 31 : if (!dh)
1419 : {
1420 0 : ereport(isServerStart ? FATAL : LOG,
1421 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1422 : errmsg("DH: could not load DH parameters")));
1423 0 : return false;
1424 : }
1425 :
1426 31 : if (SSL_CTX_set_tmp_dh(context, dh) != 1)
1427 : {
1428 0 : ereport(isServerStart ? FATAL : LOG,
1429 : (errcode(ERRCODE_CONFIG_FILE_ERROR),
1430 : errmsg("DH: could not set DH parameters: %s",
1431 : SSLerrmessage(ERR_get_error()))));
1432 0 : DH_free(dh);
1433 0 : return false;
1434 : }
1435 :
1436 31 : DH_free(dh);
1437 31 : return true;
1438 : }
1439 :
1440 : /*
1441 : * Set ECDH parameters for generating ephemeral Elliptic Curve DH
1442 : * keys. This is much simpler than the DH parameters, as we just
1443 : * need to provide the name of the curve to OpenSSL.
1444 : */
1445 : static bool
1446 31 : initialize_ecdh(SSL_CTX *context, bool isServerStart)
1447 : {
1448 : #ifndef OPENSSL_NO_ECDH
1449 31 : if (SSL_CTX_set1_groups_list(context, SSLECDHCurve) != 1)
1450 : {
1451 : /*
1452 : * OpenSSL 3.3.0 introduced proper error messages for group parsing
1453 : * errors, earlier versions returns "no SSL error reported" which is
1454 : * far from helpful. For older versions, we replace with a better
1455 : * error message. Injecting the error into the OpenSSL error queue
1456 : * need APIs from OpenSSL 3.0.
1457 : */
1458 2 : ereport(isServerStart ? FATAL : LOG,
1459 : errcode(ERRCODE_CONFIG_FILE_ERROR),
1460 : errmsg("could not set group names specified in ssl_groups: %s",
1461 : SSLerrmessageExt(ERR_get_error(),
1462 : _("No valid groups found"))),
1463 : errhint("Ensure that each group name is spelled correctly and supported by the installed version of OpenSSL."));
1464 0 : return false;
1465 : }
1466 : #endif
1467 :
1468 29 : return true;
1469 : }
1470 :
1471 : /*
1472 : * Obtain reason string for passed SSL errcode with replacement
1473 : *
1474 : * The error message supplied in replacement will be used in case the error
1475 : * code from OpenSSL is 0, else the error message from SSLerrmessage() will
1476 : * be returned.
1477 : *
1478 : * Not all versions of OpenSSL place an error on the queue even for failing
1479 : * operations, which will yield "no SSL error reported" by SSLerrmessage. This
1480 : * function can be used to ensure that a proper error message is displayed for
1481 : * versions reporting no error, while using the OpenSSL error via SSLerrmessage
1482 : * for versions where there is one.
1483 : */
1484 : static const char *
1485 2 : SSLerrmessageExt(unsigned long ecode, const char *replacement)
1486 : {
1487 2 : if (ecode == 0)
1488 2 : return replacement;
1489 : else
1490 0 : return SSLerrmessage(ecode);
1491 : }
1492 :
1493 : /*
1494 : * Obtain reason string for passed SSL errcode
1495 : *
1496 : * ERR_get_error() is used by caller to get errcode to pass here.
1497 : *
1498 : * Some caution is needed here since ERR_reason_error_string will return NULL
1499 : * if it doesn't recognize the error code, or (in OpenSSL >= 3) if the code
1500 : * represents a system errno value. We don't want to return NULL ever.
1501 : */
1502 : static const char *
1503 21 : SSLerrmessage(unsigned long ecode)
1504 : {
1505 : const char *errreason;
1506 : static char errbuf[36];
1507 :
1508 21 : if (ecode == 0)
1509 0 : return _("no SSL error reported");
1510 21 : errreason = ERR_reason_error_string(ecode);
1511 21 : if (errreason != NULL)
1512 21 : return errreason;
1513 :
1514 : /*
1515 : * In OpenSSL 3.0.0 and later, ERR_reason_error_string does not map system
1516 : * errno values anymore. (See OpenSSL source code for the explanation.)
1517 : * We can cover that shortcoming with this bit of code. Older OpenSSL
1518 : * versions don't have the ERR_SYSTEM_ERROR macro, but that's okay because
1519 : * they don't have the shortcoming either.
1520 : */
1521 : #ifdef ERR_SYSTEM_ERROR
1522 0 : if (ERR_SYSTEM_ERROR(ecode))
1523 0 : return strerror(ERR_GET_REASON(ecode));
1524 : #endif
1525 :
1526 : /* No choice but to report the numeric ecode */
1527 0 : snprintf(errbuf, sizeof(errbuf), _("SSL error code %lu"), ecode);
1528 0 : return errbuf;
1529 : }
1530 :
1531 : int
1532 176 : be_tls_get_cipher_bits(Port *port)
1533 : {
1534 : int bits;
1535 :
1536 176 : if (port->ssl)
1537 : {
1538 176 : SSL_get_cipher_bits(port->ssl, &bits);
1539 176 : return bits;
1540 : }
1541 : else
1542 0 : return 0;
1543 : }
1544 :
1545 : const char *
1546 177 : be_tls_get_version(Port *port)
1547 : {
1548 177 : if (port->ssl)
1549 177 : return SSL_get_version(port->ssl);
1550 : else
1551 0 : return NULL;
1552 : }
1553 :
1554 : const char *
1555 177 : be_tls_get_cipher(Port *port)
1556 : {
1557 177 : if (port->ssl)
1558 177 : return SSL_get_cipher(port->ssl);
1559 : else
1560 0 : return NULL;
1561 : }
1562 :
1563 : void
1564 88 : be_tls_get_peer_subject_name(Port *port, char *ptr, size_t len)
1565 : {
1566 88 : if (port->peer)
1567 27 : strlcpy(ptr, X509_NAME_to_cstring(X509_get_subject_name(port->peer)), len);
1568 : else
1569 61 : ptr[0] = '\0';
1570 88 : }
1571 :
1572 : void
1573 89 : be_tls_get_peer_issuer_name(Port *port, char *ptr, size_t len)
1574 : {
1575 89 : if (port->peer)
1576 28 : strlcpy(ptr, X509_NAME_to_cstring(X509_get_issuer_name(port->peer)), len);
1577 : else
1578 61 : ptr[0] = '\0';
1579 89 : }
1580 :
1581 : void
1582 89 : be_tls_get_peer_serial(Port *port, char *ptr, size_t len)
1583 : {
1584 89 : if (port->peer)
1585 : {
1586 : ASN1_INTEGER *serial;
1587 : BIGNUM *b;
1588 : char *decimal;
1589 :
1590 28 : serial = X509_get_serialNumber(port->peer);
1591 28 : b = ASN1_INTEGER_to_BN(serial, NULL);
1592 28 : decimal = BN_bn2dec(b);
1593 :
1594 28 : BN_free(b);
1595 28 : strlcpy(ptr, decimal, len);
1596 28 : OPENSSL_free(decimal);
1597 : }
1598 : else
1599 61 : ptr[0] = '\0';
1600 89 : }
1601 :
1602 : char *
1603 4 : be_tls_get_certificate_hash(Port *port, size_t *len)
1604 : {
1605 : X509 *server_cert;
1606 : char *cert_hash;
1607 4 : const EVP_MD *algo_type = NULL;
1608 : unsigned char hash[EVP_MAX_MD_SIZE]; /* size for SHA-512 */
1609 : unsigned int hash_size;
1610 : int algo_nid;
1611 :
1612 4 : *len = 0;
1613 4 : server_cert = SSL_get_certificate(port->ssl);
1614 4 : if (server_cert == NULL)
1615 0 : return NULL;
1616 :
1617 : /*
1618 : * Get the signature algorithm of the certificate to determine the hash
1619 : * algorithm to use for the result. Prefer X509_get_signature_info(),
1620 : * introduced in OpenSSL 1.1.1, which can handle RSA-PSS signatures.
1621 : */
1622 : #if HAVE_X509_GET_SIGNATURE_INFO
1623 4 : if (!X509_get_signature_info(server_cert, &algo_nid, NULL, NULL, NULL))
1624 : #else
1625 : if (!OBJ_find_sigid_algs(X509_get_signature_nid(server_cert),
1626 : &algo_nid, NULL))
1627 : #endif
1628 0 : elog(ERROR, "could not determine server certificate signature algorithm");
1629 :
1630 : /*
1631 : * The TLS server's certificate bytes need to be hashed with SHA-256 if
1632 : * its signature algorithm is MD5 or SHA-1 as per RFC 5929
1633 : * (https://tools.ietf.org/html/rfc5929#section-4.1). If something else
1634 : * is used, the same hash as the signature algorithm is used.
1635 : */
1636 4 : switch (algo_nid)
1637 : {
1638 0 : case NID_md5:
1639 : case NID_sha1:
1640 0 : algo_type = EVP_sha256();
1641 0 : break;
1642 4 : default:
1643 4 : algo_type = EVP_get_digestbynid(algo_nid);
1644 4 : if (algo_type == NULL)
1645 0 : elog(ERROR, "could not find digest for NID %s",
1646 : OBJ_nid2sn(algo_nid));
1647 4 : break;
1648 : }
1649 :
1650 : /* generate and save the certificate hash */
1651 4 : if (!X509_digest(server_cert, algo_type, hash, &hash_size))
1652 0 : elog(ERROR, "could not generate server certificate hash");
1653 :
1654 4 : cert_hash = palloc(hash_size);
1655 4 : memcpy(cert_hash, hash, hash_size);
1656 4 : *len = hash_size;
1657 :
1658 4 : return cert_hash;
1659 : }
1660 :
1661 : /*
1662 : * Convert an X509 subject name to a cstring.
1663 : *
1664 : */
1665 : static char *
1666 67 : X509_NAME_to_cstring(X509_NAME *name)
1667 : {
1668 67 : BIO *membuf = BIO_new(BIO_s_mem());
1669 : int i,
1670 : nid,
1671 67 : count = X509_NAME_entry_count(name);
1672 : X509_NAME_ENTRY *e;
1673 : ASN1_STRING *v;
1674 : const char *field_name;
1675 : size_t size;
1676 : char nullterm;
1677 : char *sp;
1678 : char *dp;
1679 : char *result;
1680 :
1681 67 : if (membuf == NULL)
1682 0 : ereport(ERROR,
1683 : (errcode(ERRCODE_OUT_OF_MEMORY),
1684 : errmsg("could not create BIO")));
1685 :
1686 67 : (void) BIO_set_close(membuf, BIO_CLOSE);
1687 145 : for (i = 0; i < count; i++)
1688 : {
1689 78 : e = X509_NAME_get_entry(name, i);
1690 78 : nid = OBJ_obj2nid(X509_NAME_ENTRY_get_object(e));
1691 78 : if (nid == NID_undef)
1692 0 : ereport(ERROR,
1693 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1694 : errmsg("could not get NID for ASN1_OBJECT object")));
1695 78 : v = X509_NAME_ENTRY_get_data(e);
1696 78 : field_name = OBJ_nid2sn(nid);
1697 78 : if (field_name == NULL)
1698 0 : field_name = OBJ_nid2ln(nid);
1699 78 : if (field_name == NULL)
1700 0 : ereport(ERROR,
1701 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1702 : errmsg("could not convert NID %d to an ASN1_OBJECT structure", nid)));
1703 78 : BIO_printf(membuf, "/%s=", field_name);
1704 78 : ASN1_STRING_print_ex(membuf, v,
1705 : ((ASN1_STRFLGS_RFC2253 & ~ASN1_STRFLGS_ESC_MSB)
1706 : | ASN1_STRFLGS_UTF8_CONVERT));
1707 : }
1708 :
1709 : /* ensure null termination of the BIO's content */
1710 67 : nullterm = '\0';
1711 67 : BIO_write(membuf, &nullterm, 1);
1712 67 : size = BIO_get_mem_data(membuf, &sp);
1713 67 : dp = pg_any_to_server(sp, size - 1, PG_UTF8);
1714 :
1715 67 : result = pstrdup(dp);
1716 67 : if (dp != sp)
1717 0 : pfree(dp);
1718 67 : if (BIO_free(membuf) != 1)
1719 0 : elog(ERROR, "could not free OpenSSL BIO structure");
1720 :
1721 67 : return result;
1722 : }
1723 :
1724 : /*
1725 : * Convert TLS protocol version GUC enum to OpenSSL values
1726 : *
1727 : * This is a straightforward one-to-one mapping, but doing it this way makes
1728 : * the definitions of ssl_min_protocol_version and ssl_max_protocol_version
1729 : * independent of OpenSSL availability and version.
1730 : *
1731 : * If a version is passed that is not supported by the current OpenSSL
1732 : * version, then we return -1. If a nonnegative value is returned,
1733 : * subsequent code can assume it's working with a supported version.
1734 : *
1735 : * Note: this is rather similar to libpq's routine in fe-secure-openssl.c,
1736 : * so make sure to update both routines if changing this one.
1737 : */
1738 : static int
1739 33 : ssl_protocol_version_to_openssl(int v)
1740 : {
1741 33 : switch (v)
1742 : {
1743 0 : case PG_TLS_ANY:
1744 0 : return 0;
1745 0 : case PG_TLS1_VERSION:
1746 0 : return TLS1_VERSION;
1747 1 : case PG_TLS1_1_VERSION:
1748 : #ifdef TLS1_1_VERSION
1749 1 : return TLS1_1_VERSION;
1750 : #else
1751 : break;
1752 : #endif
1753 32 : case PG_TLS1_2_VERSION:
1754 : #ifdef TLS1_2_VERSION
1755 32 : return TLS1_2_VERSION;
1756 : #else
1757 : break;
1758 : #endif
1759 0 : case PG_TLS1_3_VERSION:
1760 : #ifdef TLS1_3_VERSION
1761 0 : return TLS1_3_VERSION;
1762 : #else
1763 : break;
1764 : #endif
1765 : }
1766 :
1767 0 : return -1;
1768 : }
1769 :
1770 : /*
1771 : * Likewise provide a mapping to strings.
1772 : */
1773 : static const char *
1774 0 : ssl_protocol_version_to_string(int v)
1775 : {
1776 0 : switch (v)
1777 : {
1778 0 : case PG_TLS_ANY:
1779 0 : return "any";
1780 0 : case PG_TLS1_VERSION:
1781 0 : return "TLSv1";
1782 0 : case PG_TLS1_1_VERSION:
1783 0 : return "TLSv1.1";
1784 0 : case PG_TLS1_2_VERSION:
1785 0 : return "TLSv1.2";
1786 0 : case PG_TLS1_3_VERSION:
1787 0 : return "TLSv1.3";
1788 : }
1789 :
1790 0 : return "(unrecognized)";
1791 : }
1792 :
1793 :
1794 : static void
1795 32 : default_openssl_tls_init(SSL_CTX *context, bool isServerStart)
1796 : {
1797 32 : if (isServerStart)
1798 : {
1799 29 : if (ssl_passphrase_command[0])
1800 7 : SSL_CTX_set_default_passwd_cb(context, ssl_external_passwd_cb);
1801 : }
1802 : else
1803 : {
1804 3 : if (ssl_passphrase_command[0] && ssl_passphrase_command_supports_reload)
1805 1 : SSL_CTX_set_default_passwd_cb(context, ssl_external_passwd_cb);
1806 : else
1807 :
1808 : /*
1809 : * If reloading and no external command is configured, override
1810 : * OpenSSL's default handling of passphrase-protected files,
1811 : * because we don't want to prompt for a passphrase in an
1812 : * already-running server.
1813 : */
1814 2 : SSL_CTX_set_default_passwd_cb(context, dummy_ssl_passwd_cb);
1815 : }
1816 32 : }
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