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fe-secure-openssl.c
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1 /*-------------------------------------------------------------------------
2  *
3  * fe-secure-openssl.c
4  * OpenSSL support
5  *
6  *
7  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  *
11  * IDENTIFICATION
12  * src/interfaces/libpq/fe-secure-openssl.c
13  *
14  * NOTES
15  *
16  * We don't provide informational callbacks here (like
17  * info_cb() in be-secure.c), since there's no good mechanism to
18  * display such information to the user.
19  *
20  *-------------------------------------------------------------------------
21  */
22 
23 #include "postgres_fe.h"
24 
25 #include <signal.h>
26 #include <fcntl.h>
27 #include <ctype.h>
28 
29 #include "libpq-fe.h"
30 #include "fe-auth.h"
31 #include "fe-secure-common.h"
32 #include "libpq-int.h"
33 #include "common/openssl.h"
34 
35 #ifdef WIN32
36 #include "win32.h"
37 #else
38 #include <sys/socket.h>
39 #include <unistd.h>
40 #include <netdb.h>
41 #include <netinet/in.h>
42 #ifdef HAVE_NETINET_TCP_H
43 #include <netinet/tcp.h>
44 #endif
45 #include <arpa/inet.h>
46 #endif
47 
48 #include <sys/stat.h>
49 
50 #ifdef ENABLE_THREAD_SAFETY
51 #ifdef WIN32
52 #include "pthread-win32.h"
53 #else
54 #include <pthread.h>
55 #endif
56 #endif
57 
58 #include <openssl/ssl.h>
59 #include <openssl/conf.h>
60 #ifdef USE_SSL_ENGINE
61 #include <openssl/engine.h>
62 #endif
63 #include <openssl/x509v3.h>
64 
65 static int verify_cb(int ok, X509_STORE_CTX *ctx);
67  ASN1_STRING *name,
68  char **store_name);
69 static void destroy_ssl_system(void);
70 static int initialize_SSL(PGconn *conn);
72 static char *SSLerrmessage(unsigned long ecode);
73 static void SSLerrfree(char *buf);
74 static int PQssl_passwd_cb(char *buf, int size, int rwflag, void *userdata);
75 
76 static int my_sock_read(BIO *h, char *buf, int size);
77 static int my_sock_write(BIO *h, const char *buf, int size);
78 static BIO_METHOD *my_BIO_s_socket(void);
79 static int my_SSL_set_fd(PGconn *conn, int fd);
80 
81 
82 static bool pq_init_ssl_lib = true;
83 static bool pq_init_crypto_lib = true;
84 
85 static bool ssl_lib_initialized = false;
86 
87 #ifdef ENABLE_THREAD_SAFETY
88 static long ssl_open_connections = 0;
89 
90 #ifndef WIN32
91 static pthread_mutex_t ssl_config_mutex = PTHREAD_MUTEX_INITIALIZER;
92 #else
93 static pthread_mutex_t ssl_config_mutex = NULL;
94 static long win32_ssl_create_mutex = 0;
95 #endif
96 #endif /* ENABLE_THREAD_SAFETY */
97 
99 static int ssl_protocol_version_to_openssl(const char *protocol);
100 
101 /* ------------------------------------------------------------ */
102 /* Procedures common to all secure sessions */
103 /* ------------------------------------------------------------ */
104 
105 void
106 pgtls_init_library(bool do_ssl, int do_crypto)
107 {
108 #ifdef ENABLE_THREAD_SAFETY
109 
110  /*
111  * Disallow changing the flags while we have open connections, else we'd
112  * get completely confused.
113  */
114  if (ssl_open_connections != 0)
115  return;
116 #endif
117 
118  pq_init_ssl_lib = do_ssl;
119  pq_init_crypto_lib = do_crypto;
120 }
121 
124 {
125  /* First time through? */
126  if (conn->ssl == NULL)
127  {
128  /*
129  * Create a connection-specific SSL object, and load client
130  * certificate, private key, and trusted CA certs.
131  */
132  if (initialize_SSL(conn) != 0)
133  {
134  /* initialize_SSL already put a message in conn->errorMessage */
135  pgtls_close(conn);
136  return PGRES_POLLING_FAILED;
137  }
138  }
139 
140  /* Begin or continue the actual handshake */
141  return open_client_SSL(conn);
142 }
143 
144 ssize_t
145 pgtls_read(PGconn *conn, void *ptr, size_t len)
146 {
147  ssize_t n;
148  int result_errno = 0;
149  char sebuf[PG_STRERROR_R_BUFLEN];
150  int err;
151  unsigned long ecode;
152 
153 rloop:
154 
155  /*
156  * Prepare to call SSL_get_error() by clearing thread's OpenSSL error
157  * queue. In general, the current thread's error queue must be empty
158  * before the TLS/SSL I/O operation is attempted, or SSL_get_error() will
159  * not work reliably. Since the possibility exists that other OpenSSL
160  * clients running in the same thread but not under our control will fail
161  * to call ERR_get_error() themselves (after their own I/O operations),
162  * pro-actively clear the per-thread error queue now.
163  */
164  SOCK_ERRNO_SET(0);
165  ERR_clear_error();
166  n = SSL_read(conn->ssl, ptr, len);
167  err = SSL_get_error(conn->ssl, n);
168 
169  /*
170  * Other clients of OpenSSL may fail to call ERR_get_error(), but we
171  * always do, so as to not cause problems for OpenSSL clients that don't
172  * call ERR_clear_error() defensively. Be sure that this happens by
173  * calling now. SSL_get_error() relies on the OpenSSL per-thread error
174  * queue being intact, so this is the earliest possible point
175  * ERR_get_error() may be called.
176  */
177  ecode = (err != SSL_ERROR_NONE || n < 0) ? ERR_get_error() : 0;
178  switch (err)
179  {
180  case SSL_ERROR_NONE:
181  if (n < 0)
182  {
183  /* Not supposed to happen, so we don't translate the msg */
185  "SSL_read failed but did not provide error information\n");
186  /* assume the connection is broken */
187  result_errno = ECONNRESET;
188  }
189  break;
190  case SSL_ERROR_WANT_READ:
191  n = 0;
192  break;
193  case SSL_ERROR_WANT_WRITE:
194 
195  /*
196  * Returning 0 here would cause caller to wait for read-ready,
197  * which is not correct since what SSL wants is wait for
198  * write-ready. The former could get us stuck in an infinite
199  * wait, so don't risk it; busy-loop instead.
200  */
201  goto rloop;
202  case SSL_ERROR_SYSCALL:
203  if (n < 0)
204  {
205  result_errno = SOCK_ERRNO;
206  if (result_errno == EPIPE ||
207  result_errno == ECONNRESET)
209  libpq_gettext("server closed the connection unexpectedly\n"
210  "\tThis probably means the server terminated abnormally\n"
211  "\tbefore or while processing the request.\n"));
212  else
214  libpq_gettext("SSL SYSCALL error: %s\n"),
215  SOCK_STRERROR(result_errno,
216  sebuf, sizeof(sebuf)));
217  }
218  else
219  {
221  libpq_gettext("SSL SYSCALL error: EOF detected\n"));
222  /* assume the connection is broken */
223  result_errno = ECONNRESET;
224  n = -1;
225  }
226  break;
227  case SSL_ERROR_SSL:
228  {
229  char *errm = SSLerrmessage(ecode);
230 
232  libpq_gettext("SSL error: %s\n"), errm);
233  SSLerrfree(errm);
234  /* assume the connection is broken */
235  result_errno = ECONNRESET;
236  n = -1;
237  break;
238  }
239  case SSL_ERROR_ZERO_RETURN:
240 
241  /*
242  * Per OpenSSL documentation, this error code is only returned for
243  * a clean connection closure, so we should not report it as a
244  * server crash.
245  */
247  libpq_gettext("SSL connection has been closed unexpectedly\n"));
248  result_errno = ECONNRESET;
249  n = -1;
250  break;
251  default:
253  libpq_gettext("unrecognized SSL error code: %d\n"),
254  err);
255  /* assume the connection is broken */
256  result_errno = ECONNRESET;
257  n = -1;
258  break;
259  }
260 
261  /* ensure we return the intended errno to caller */
262  SOCK_ERRNO_SET(result_errno);
263 
264  return n;
265 }
266 
267 bool
269 {
270  return SSL_pending(conn->ssl) > 0;
271 }
272 
273 ssize_t
274 pgtls_write(PGconn *conn, const void *ptr, size_t len)
275 {
276  ssize_t n;
277  int result_errno = 0;
278  char sebuf[PG_STRERROR_R_BUFLEN];
279  int err;
280  unsigned long ecode;
281 
282  SOCK_ERRNO_SET(0);
283  ERR_clear_error();
284  n = SSL_write(conn->ssl, ptr, len);
285  err = SSL_get_error(conn->ssl, n);
286  ecode = (err != SSL_ERROR_NONE || n < 0) ? ERR_get_error() : 0;
287  switch (err)
288  {
289  case SSL_ERROR_NONE:
290  if (n < 0)
291  {
292  /* Not supposed to happen, so we don't translate the msg */
294  "SSL_write failed but did not provide error information\n");
295  /* assume the connection is broken */
296  result_errno = ECONNRESET;
297  }
298  break;
299  case SSL_ERROR_WANT_READ:
300 
301  /*
302  * Returning 0 here causes caller to wait for write-ready, which
303  * is not really the right thing, but it's the best we can do.
304  */
305  n = 0;
306  break;
307  case SSL_ERROR_WANT_WRITE:
308  n = 0;
309  break;
310  case SSL_ERROR_SYSCALL:
311  if (n < 0)
312  {
313  result_errno = SOCK_ERRNO;
314  if (result_errno == EPIPE || result_errno == ECONNRESET)
316  libpq_gettext("server closed the connection unexpectedly\n"
317  "\tThis probably means the server terminated abnormally\n"
318  "\tbefore or while processing the request.\n"));
319  else
321  libpq_gettext("SSL SYSCALL error: %s\n"),
322  SOCK_STRERROR(result_errno,
323  sebuf, sizeof(sebuf)));
324  }
325  else
326  {
328  libpq_gettext("SSL SYSCALL error: EOF detected\n"));
329  /* assume the connection is broken */
330  result_errno = ECONNRESET;
331  n = -1;
332  }
333  break;
334  case SSL_ERROR_SSL:
335  {
336  char *errm = SSLerrmessage(ecode);
337 
339  libpq_gettext("SSL error: %s\n"), errm);
340  SSLerrfree(errm);
341  /* assume the connection is broken */
342  result_errno = ECONNRESET;
343  n = -1;
344  break;
345  }
346  case SSL_ERROR_ZERO_RETURN:
347 
348  /*
349  * Per OpenSSL documentation, this error code is only returned for
350  * a clean connection closure, so we should not report it as a
351  * server crash.
352  */
354  libpq_gettext("SSL connection has been closed unexpectedly\n"));
355  result_errno = ECONNRESET;
356  n = -1;
357  break;
358  default:
360  libpq_gettext("unrecognized SSL error code: %d\n"),
361  err);
362  /* assume the connection is broken */
363  result_errno = ECONNRESET;
364  n = -1;
365  break;
366  }
367 
368  /* ensure we return the intended errno to caller */
369  SOCK_ERRNO_SET(result_errno);
370 
371  return n;
372 }
373 
374 #ifdef HAVE_X509_GET_SIGNATURE_NID
375 char *
376 pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len)
377 {
378  X509 *peer_cert;
379  const EVP_MD *algo_type;
380  unsigned char hash[EVP_MAX_MD_SIZE]; /* size for SHA-512 */
381  unsigned int hash_size;
382  int algo_nid;
383  char *cert_hash;
384 
385  *len = 0;
386 
387  if (!conn->peer)
388  return NULL;
389 
390  peer_cert = conn->peer;
391 
392  /*
393  * Get the signature algorithm of the certificate to determine the hash
394  * algorithm to use for the result.
395  */
396  if (!OBJ_find_sigid_algs(X509_get_signature_nid(peer_cert),
397  &algo_nid, NULL))
398  {
400  libpq_gettext("could not determine server certificate signature algorithm\n"));
401  return NULL;
402  }
403 
404  /*
405  * The TLS server's certificate bytes need to be hashed with SHA-256 if
406  * its signature algorithm is MD5 or SHA-1 as per RFC 5929
407  * (https://tools.ietf.org/html/rfc5929#section-4.1). If something else
408  * is used, the same hash as the signature algorithm is used.
409  */
410  switch (algo_nid)
411  {
412  case NID_md5:
413  case NID_sha1:
414  algo_type = EVP_sha256();
415  break;
416  default:
417  algo_type = EVP_get_digestbynid(algo_nid);
418  if (algo_type == NULL)
419  {
421  libpq_gettext("could not find digest for NID %s\n"),
422  OBJ_nid2sn(algo_nid));
423  return NULL;
424  }
425  break;
426  }
427 
428  if (!X509_digest(peer_cert, algo_type, hash, &hash_size))
429  {
431  libpq_gettext("could not generate peer certificate hash\n"));
432  return NULL;
433  }
434 
435  /* save result */
436  cert_hash = malloc(hash_size);
437  if (cert_hash == NULL)
438  {
440  libpq_gettext("out of memory\n"));
441  return NULL;
442  }
443  memcpy(cert_hash, hash, hash_size);
444  *len = hash_size;
445 
446  return cert_hash;
447 }
448 #endif /* HAVE_X509_GET_SIGNATURE_NID */
449 
450 /* ------------------------------------------------------------ */
451 /* OpenSSL specific code */
452 /* ------------------------------------------------------------ */
453 
454 /*
455  * Certificate verification callback
456  *
457  * This callback allows us to log intermediate problems during
458  * verification, but there doesn't seem to be a clean way to get
459  * our PGconn * structure. So we can't log anything!
460  *
461  * This callback also allows us to override the default acceptance
462  * criteria (e.g., accepting self-signed or expired certs), but
463  * for now we accept the default checks.
464  */
465 static int
466 verify_cb(int ok, X509_STORE_CTX *ctx)
467 {
468  return ok;
469 }
470 
471 
472 /*
473  * OpenSSL-specific wrapper around
474  * pq_verify_peer_name_matches_certificate_name(), converting the ASN1_STRING
475  * into a plain C string.
476  */
477 static int
479  char **store_name)
480 {
481  int len;
482  const unsigned char *namedata;
483 
484  /* Should not happen... */
485  if (name_entry == NULL)
486  {
488  libpq_gettext("SSL certificate's name entry is missing\n"));
489  return -1;
490  }
491 
492  /*
493  * GEN_DNS can be only IA5String, equivalent to US ASCII.
494  */
495 #ifdef HAVE_ASN1_STRING_GET0_DATA
496  namedata = ASN1_STRING_get0_data(name_entry);
497 #else
498  namedata = ASN1_STRING_data(name_entry);
499 #endif
500  len = ASN1_STRING_length(name_entry);
501 
502  /* OK to cast from unsigned to plain char, since it's all ASCII. */
503  return pq_verify_peer_name_matches_certificate_name(conn, (const char *) namedata, len, store_name);
504 }
505 
506 /*
507  * Verify that the server certificate matches the hostname we connected to.
508  *
509  * The certificate's Common Name and Subject Alternative Names are considered.
510  */
511 int
513  int *names_examined,
514  char **first_name)
515 {
516  STACK_OF(GENERAL_NAME) * peer_san;
517  int i;
518  int rc = 0;
519 
520  /*
521  * First, get the Subject Alternative Names (SANs) from the certificate,
522  * and compare them against the originally given hostname.
523  */
524  peer_san = (STACK_OF(GENERAL_NAME) *)
525  X509_get_ext_d2i(conn->peer, NID_subject_alt_name, NULL, NULL);
526 
527  if (peer_san)
528  {
529  int san_len = sk_GENERAL_NAME_num(peer_san);
530 
531  for (i = 0; i < san_len; i++)
532  {
533  const GENERAL_NAME *name = sk_GENERAL_NAME_value(peer_san, i);
534 
535  if (name->type == GEN_DNS)
536  {
537  char *alt_name;
538 
539  (*names_examined)++;
541  name->d.dNSName,
542  &alt_name);
543 
544  if (alt_name)
545  {
546  if (!*first_name)
547  *first_name = alt_name;
548  else
549  free(alt_name);
550  }
551  }
552  if (rc != 0)
553  break;
554  }
555  sk_GENERAL_NAME_pop_free(peer_san, GENERAL_NAME_free);
556  }
557 
558  /*
559  * If there is no subjectAltName extension of type dNSName, check the
560  * Common Name.
561  *
562  * (Per RFC 2818 and RFC 6125, if the subjectAltName extension of type
563  * dNSName is present, the CN must be ignored.)
564  */
565  if (*names_examined == 0)
566  {
567  X509_NAME *subject_name;
568 
569  subject_name = X509_get_subject_name(conn->peer);
570  if (subject_name != NULL)
571  {
572  int cn_index;
573 
574  cn_index = X509_NAME_get_index_by_NID(subject_name,
575  NID_commonName, -1);
576  if (cn_index >= 0)
577  {
578  (*names_examined)++;
580  X509_NAME_ENTRY_get_data(X509_NAME_get_entry(subject_name, cn_index)),
581  first_name);
582  }
583  }
584  }
585 
586  return rc;
587 }
588 
589 #if defined(ENABLE_THREAD_SAFETY) && defined(HAVE_CRYPTO_LOCK)
590 /*
591  * Callback functions for OpenSSL internal locking. (OpenSSL 1.1.0
592  * does its own locking, and doesn't need these anymore. The
593  * CRYPTO_lock() function was removed in 1.1.0, when the callbacks
594  * were made obsolete, so we assume that if CRYPTO_lock() exists,
595  * the callbacks are still required.)
596  */
597 
598 static unsigned long
599 pq_threadidcallback(void)
600 {
601  /*
602  * This is not standards-compliant. pthread_self() returns pthread_t, and
603  * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
604  * it, so we have to do it.
605  */
606  return (unsigned long) pthread_self();
607 }
608 
609 static pthread_mutex_t *pq_lockarray;
610 
611 static void
612 pq_lockingcallback(int mode, int n, const char *file, int line)
613 {
614  if (mode & CRYPTO_LOCK)
615  {
616  if (pthread_mutex_lock(&pq_lockarray[n]))
617  PGTHREAD_ERROR("failed to lock mutex");
618  }
619  else
620  {
621  if (pthread_mutex_unlock(&pq_lockarray[n]))
622  PGTHREAD_ERROR("failed to unlock mutex");
623  }
624 }
625 #endif /* ENABLE_THREAD_SAFETY && HAVE_CRYPTO_LOCK */
626 
627 /*
628  * Initialize SSL library.
629  *
630  * In threadsafe mode, this includes setting up libcrypto callback functions
631  * to do thread locking.
632  *
633  * If the caller has told us (through PQinitOpenSSL) that he's taking care
634  * of libcrypto, we expect that callbacks are already set, and won't try to
635  * override it.
636  */
637 int
639 {
640 #ifdef ENABLE_THREAD_SAFETY
641 #ifdef WIN32
642  /* Also see similar code in fe-connect.c, default_threadlock() */
643  if (ssl_config_mutex == NULL)
644  {
645  while (InterlockedExchange(&win32_ssl_create_mutex, 1) == 1)
646  /* loop, another thread own the lock */ ;
647  if (ssl_config_mutex == NULL)
648  {
649  if (pthread_mutex_init(&ssl_config_mutex, NULL))
650  return -1;
651  }
652  InterlockedExchange(&win32_ssl_create_mutex, 0);
653  }
654 #endif
655  if (pthread_mutex_lock(&ssl_config_mutex))
656  return -1;
657 
658 #ifdef HAVE_CRYPTO_LOCK
659  if (pq_init_crypto_lib)
660  {
661  /*
662  * If necessary, set up an array to hold locks for libcrypto.
663  * libcrypto will tell us how big to make this array.
664  */
665  if (pq_lockarray == NULL)
666  {
667  int i;
668 
669  pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
670  if (!pq_lockarray)
671  {
672  pthread_mutex_unlock(&ssl_config_mutex);
673  return -1;
674  }
675  for (i = 0; i < CRYPTO_num_locks(); i++)
676  {
677  if (pthread_mutex_init(&pq_lockarray[i], NULL))
678  {
679  free(pq_lockarray);
680  pq_lockarray = NULL;
681  pthread_mutex_unlock(&ssl_config_mutex);
682  return -1;
683  }
684  }
685  }
686 
687  if (ssl_open_connections++ == 0)
688  {
689  /*
690  * These are only required for threaded libcrypto applications,
691  * but make sure we don't stomp on them if they're already set.
692  */
693  if (CRYPTO_get_id_callback() == NULL)
694  CRYPTO_set_id_callback(pq_threadidcallback);
695  if (CRYPTO_get_locking_callback() == NULL)
696  CRYPTO_set_locking_callback(pq_lockingcallback);
697  }
698  }
699 #endif /* HAVE_CRYPTO_LOCK */
700 #endif /* ENABLE_THREAD_SAFETY */
701 
702  if (!ssl_lib_initialized)
703  {
704  if (pq_init_ssl_lib)
705  {
706 #ifdef HAVE_OPENSSL_INIT_SSL
707  OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
708 #else
709  OPENSSL_config(NULL);
710  SSL_library_init();
711  SSL_load_error_strings();
712 #endif
713  }
714  ssl_lib_initialized = true;
715  }
716 
717 #ifdef ENABLE_THREAD_SAFETY
718  pthread_mutex_unlock(&ssl_config_mutex);
719 #endif
720  return 0;
721 }
722 
723 /*
724  * This function is needed because if the libpq library is unloaded
725  * from the application, the callback functions will no longer exist when
726  * libcrypto is used by other parts of the system. For this reason,
727  * we unregister the callback functions when the last libpq
728  * connection is closed. (The same would apply for OpenSSL callbacks
729  * if we had any.)
730  *
731  * Callbacks are only set when we're compiled in threadsafe mode, so
732  * we only need to remove them in this case. They are also not needed
733  * with OpenSSL 1.1.0 anymore.
734  */
735 static void
737 {
738 #if defined(ENABLE_THREAD_SAFETY) && defined(HAVE_CRYPTO_LOCK)
739  /* Mutex is created in pgtls_init() */
740  if (pthread_mutex_lock(&ssl_config_mutex))
741  return;
742 
743  if (pq_init_crypto_lib && ssl_open_connections > 0)
744  --ssl_open_connections;
745 
746  if (pq_init_crypto_lib && ssl_open_connections == 0)
747  {
748  /*
749  * No connections left, unregister libcrypto callbacks, if no one
750  * registered different ones in the meantime.
751  */
752  if (CRYPTO_get_locking_callback() == pq_lockingcallback)
753  CRYPTO_set_locking_callback(NULL);
754  if (CRYPTO_get_id_callback() == pq_threadidcallback)
755  CRYPTO_set_id_callback(NULL);
756 
757  /*
758  * We don't free the lock array. If we get another connection in this
759  * process, we will just re-use them with the existing mutexes.
760  *
761  * This means we leak a little memory on repeated load/unload of the
762  * library.
763  */
764  }
765 
766  pthread_mutex_unlock(&ssl_config_mutex);
767 #endif
768 }
769 
770 /*
771  * Create per-connection SSL object, and load the client certificate,
772  * private key, and trusted CA certs.
773  *
774  * Returns 0 if OK, -1 on failure (with a message in conn->errorMessage).
775  */
776 static int
778 {
779  SSL_CTX *SSL_context;
780  struct stat buf;
781  char homedir[MAXPGPATH];
782  char fnbuf[MAXPGPATH];
783  char sebuf[PG_STRERROR_R_BUFLEN];
784  bool have_homedir;
785  bool have_cert;
786  bool have_rootcert;
787  EVP_PKEY *pkey = NULL;
788 
789  /*
790  * We'll need the home directory if any of the relevant parameters are
791  * defaulted. If pqGetHomeDirectory fails, act as though none of the
792  * files could be found.
793  */
794  if (!(conn->sslcert && strlen(conn->sslcert) > 0) ||
795  !(conn->sslkey && strlen(conn->sslkey) > 0) ||
796  !(conn->sslrootcert && strlen(conn->sslrootcert) > 0) ||
797  !(conn->sslcrl && strlen(conn->sslcrl) > 0))
798  have_homedir = pqGetHomeDirectory(homedir, sizeof(homedir));
799  else /* won't need it */
800  have_homedir = false;
801 
802  /*
803  * Create a new SSL_CTX object.
804  *
805  * We used to share a single SSL_CTX between all connections, but it was
806  * complicated if connections used different certificates. So now we
807  * create a separate context for each connection, and accept the overhead.
808  */
809  SSL_context = SSL_CTX_new(SSLv23_method());
810  if (!SSL_context)
811  {
812  char *err = SSLerrmessage(ERR_get_error());
813 
815  libpq_gettext("could not create SSL context: %s\n"),
816  err);
817  SSLerrfree(err);
818  return -1;
819  }
820 
821  /*
822  * Delegate the client cert password prompt to the libpq wrapper callback
823  * if any is defined.
824  *
825  * If the application hasn't installed its own and the sslpassword
826  * parameter is non-null, we install ours now to make sure we supply
827  * PGconn->sslpassword to OpenSSL instead of letting it prompt on stdin.
828  *
829  * This will replace OpenSSL's default PEM_def_callback (which prompts on
830  * stdin), but we're only setting it for this SSL context so it's
831  * harmless.
832  */
833  if (PQsslKeyPassHook
834  || (conn->sslpassword && strlen(conn->sslpassword) > 0))
835  {
836  SSL_CTX_set_default_passwd_cb(SSL_context, PQssl_passwd_cb);
837  SSL_CTX_set_default_passwd_cb_userdata(SSL_context, conn);
838  }
839 
840  /* Disable old protocol versions */
841  SSL_CTX_set_options(SSL_context, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
842 
843  /* Set the minimum and maximum protocol versions if necessary */
844  if (conn->ssl_min_protocol_version &&
845  strlen(conn->ssl_min_protocol_version) != 0)
846  {
847  int ssl_min_ver;
848 
850 
851  if (ssl_min_ver == -1)
852  {
854  libpq_gettext("invalid value \"%s\" for minimum SSL protocol version\n"),
856  SSL_CTX_free(SSL_context);
857  return -1;
858  }
859 
860  if (!SSL_CTX_set_min_proto_version(SSL_context, ssl_min_ver))
861  {
862  char *err = SSLerrmessage(ERR_get_error());
863 
865  libpq_gettext("could not set minimum SSL protocol version: %s\n"),
866  err);
867  SSLerrfree(err);
868  SSL_CTX_free(SSL_context);
869  return -1;
870  }
871  }
872 
873  if (conn->ssl_max_protocol_version &&
874  strlen(conn->ssl_max_protocol_version) != 0)
875  {
876  int ssl_max_ver;
877 
879 
880  if (ssl_max_ver == -1)
881  {
883  libpq_gettext("invalid value \"%s\" for maximum SSL protocol version\n"),
885  SSL_CTX_free(SSL_context);
886  return -1;
887  }
888 
889  if (!SSL_CTX_set_max_proto_version(SSL_context, ssl_max_ver))
890  {
891  char *err = SSLerrmessage(ERR_get_error());
892 
894  libpq_gettext("could not set maximum SSL protocol version: %s\n"),
895  err);
896  SSLerrfree(err);
897  SSL_CTX_free(SSL_context);
898  return -1;
899  }
900  }
901 
902  /*
903  * Disable OpenSSL's moving-write-buffer sanity check, because it causes
904  * unnecessary failures in nonblocking send cases.
905  */
906  SSL_CTX_set_mode(SSL_context, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
907 
908  /*
909  * If the root cert file exists, load it so we can perform certificate
910  * verification. If sslmode is "verify-full" we will also do further
911  * verification after the connection has been completed.
912  */
913  if (conn->sslrootcert && strlen(conn->sslrootcert) > 0)
914  strlcpy(fnbuf, conn->sslrootcert, sizeof(fnbuf));
915  else if (have_homedir)
916  snprintf(fnbuf, sizeof(fnbuf), "%s/%s", homedir, ROOT_CERT_FILE);
917  else
918  fnbuf[0] = '\0';
919 
920  if (fnbuf[0] != '\0' &&
921  stat(fnbuf, &buf) == 0)
922  {
923  X509_STORE *cvstore;
924 
925  if (SSL_CTX_load_verify_locations(SSL_context, fnbuf, NULL) != 1)
926  {
927  char *err = SSLerrmessage(ERR_get_error());
928 
930  libpq_gettext("could not read root certificate file \"%s\": %s\n"),
931  fnbuf, err);
932  SSLerrfree(err);
933  SSL_CTX_free(SSL_context);
934  return -1;
935  }
936 
937  if ((cvstore = SSL_CTX_get_cert_store(SSL_context)) != NULL)
938  {
939  if (conn->sslcrl && strlen(conn->sslcrl) > 0)
940  strlcpy(fnbuf, conn->sslcrl, sizeof(fnbuf));
941  else if (have_homedir)
942  snprintf(fnbuf, sizeof(fnbuf), "%s/%s", homedir, ROOT_CRL_FILE);
943  else
944  fnbuf[0] = '\0';
945 
946  /* Set the flags to check against the complete CRL chain */
947  if (fnbuf[0] != '\0' &&
948  X509_STORE_load_locations(cvstore, fnbuf, NULL) == 1)
949  {
950  X509_STORE_set_flags(cvstore,
951  X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL);
952  }
953  /* if not found, silently ignore; we do not require CRL */
954  ERR_clear_error();
955  }
956  have_rootcert = true;
957  }
958  else
959  {
960  /*
961  * stat() failed; assume root file doesn't exist. If sslmode is
962  * verify-ca or verify-full, this is an error. Otherwise, continue
963  * without performing any server cert verification.
964  */
965  if (conn->sslmode[0] == 'v') /* "verify-ca" or "verify-full" */
966  {
967  /*
968  * The only way to reach here with an empty filename is if
969  * pqGetHomeDirectory failed. That's a sufficiently unusual case
970  * that it seems worth having a specialized error message for it.
971  */
972  if (fnbuf[0] == '\0')
974  libpq_gettext("could not get home directory to locate root certificate file\n"
975  "Either provide the file or change sslmode to disable server certificate verification.\n"));
976  else
978  libpq_gettext("root certificate file \"%s\" does not exist\n"
979  "Either provide the file or change sslmode to disable server certificate verification.\n"), fnbuf);
980  SSL_CTX_free(SSL_context);
981  return -1;
982  }
983  have_rootcert = false;
984  }
985 
986  /* Read the client certificate file */
987  if (conn->sslcert && strlen(conn->sslcert) > 0)
988  strlcpy(fnbuf, conn->sslcert, sizeof(fnbuf));
989  else if (have_homedir)
990  snprintf(fnbuf, sizeof(fnbuf), "%s/%s", homedir, USER_CERT_FILE);
991  else
992  fnbuf[0] = '\0';
993 
994  if (fnbuf[0] == '\0')
995  {
996  /* no home directory, proceed without a client cert */
997  have_cert = false;
998  }
999  else if (stat(fnbuf, &buf) != 0)
1000  {
1001  /*
1002  * If file is not present, just go on without a client cert; server
1003  * might or might not accept the connection. Any other error,
1004  * however, is grounds for complaint.
1005  */
1006  if (errno != ENOENT && errno != ENOTDIR)
1007  {
1009  libpq_gettext("could not open certificate file \"%s\": %s\n"),
1010  fnbuf, strerror_r(errno, sebuf, sizeof(sebuf)));
1011  SSL_CTX_free(SSL_context);
1012  return -1;
1013  }
1014  have_cert = false;
1015  }
1016  else
1017  {
1018  /*
1019  * Cert file exists, so load it. Since OpenSSL doesn't provide the
1020  * equivalent of "SSL_use_certificate_chain_file", we have to load it
1021  * into the SSL context, rather than the SSL object.
1022  */
1023  if (SSL_CTX_use_certificate_chain_file(SSL_context, fnbuf) != 1)
1024  {
1025  char *err = SSLerrmessage(ERR_get_error());
1026 
1028  libpq_gettext("could not read certificate file \"%s\": %s\n"),
1029  fnbuf, err);
1030  SSLerrfree(err);
1031  SSL_CTX_free(SSL_context);
1032  return -1;
1033  }
1034 
1035  /* need to load the associated private key, too */
1036  have_cert = true;
1037  }
1038 
1039  /*
1040  * The SSL context is now loaded with the correct root and client
1041  * certificates. Create a connection-specific SSL object. The private key
1042  * is loaded directly into the SSL object. (We could load the private key
1043  * into the context, too, but we have done it this way historically, and
1044  * it doesn't really matter.)
1045  */
1046  if (!(conn->ssl = SSL_new(SSL_context)) ||
1047  !SSL_set_app_data(conn->ssl, conn) ||
1048  !my_SSL_set_fd(conn, conn->sock))
1049  {
1050  char *err = SSLerrmessage(ERR_get_error());
1051 
1053  libpq_gettext("could not establish SSL connection: %s\n"),
1054  err);
1055  SSLerrfree(err);
1056  SSL_CTX_free(SSL_context);
1057  return -1;
1058  }
1059  conn->ssl_in_use = true;
1060 
1061  /*
1062  * SSL contexts are reference counted by OpenSSL. We can free it as soon
1063  * as we have created the SSL object, and it will stick around for as long
1064  * as it's actually needed.
1065  */
1066  SSL_CTX_free(SSL_context);
1067  SSL_context = NULL;
1068 
1069  /*
1070  * Read the SSL key. If a key is specified, treat it as an engine:key
1071  * combination if there is colon present - we don't support files with
1072  * colon in the name. The exception is if the second character is a colon,
1073  * in which case it can be a Windows filename with drive specification.
1074  */
1075  if (have_cert && conn->sslkey && strlen(conn->sslkey) > 0)
1076  {
1077 #ifdef USE_SSL_ENGINE
1078  if (strchr(conn->sslkey, ':')
1079 #ifdef WIN32
1080  && conn->sslkey[1] != ':'
1081 #endif
1082  )
1083  {
1084  /* Colon, but not in second character, treat as engine:key */
1085  char *engine_str = strdup(conn->sslkey);
1086  char *engine_colon;
1087 
1088  if (engine_str == NULL)
1089  {
1091  libpq_gettext("out of memory\n"));
1092  return -1;
1093  }
1094 
1095  /* cannot return NULL because we already checked before strdup */
1096  engine_colon = strchr(engine_str, ':');
1097 
1098  *engine_colon = '\0'; /* engine_str now has engine name */
1099  engine_colon++; /* engine_colon now has key name */
1100 
1101  conn->engine = ENGINE_by_id(engine_str);
1102  if (conn->engine == NULL)
1103  {
1104  char *err = SSLerrmessage(ERR_get_error());
1105 
1107  libpq_gettext("could not load SSL engine \"%s\": %s\n"),
1108  engine_str, err);
1109  SSLerrfree(err);
1110  free(engine_str);
1111  return -1;
1112  }
1113 
1114  if (ENGINE_init(conn->engine) == 0)
1115  {
1116  char *err = SSLerrmessage(ERR_get_error());
1117 
1119  libpq_gettext("could not initialize SSL engine \"%s\": %s\n"),
1120  engine_str, err);
1121  SSLerrfree(err);
1122  ENGINE_free(conn->engine);
1123  conn->engine = NULL;
1124  free(engine_str);
1125  return -1;
1126  }
1127 
1128  pkey = ENGINE_load_private_key(conn->engine, engine_colon,
1129  NULL, NULL);
1130  if (pkey == NULL)
1131  {
1132  char *err = SSLerrmessage(ERR_get_error());
1133 
1135  libpq_gettext("could not read private SSL key \"%s\" from engine \"%s\": %s\n"),
1136  engine_colon, engine_str, err);
1137  SSLerrfree(err);
1138  ENGINE_finish(conn->engine);
1139  ENGINE_free(conn->engine);
1140  conn->engine = NULL;
1141  free(engine_str);
1142  return -1;
1143  }
1144  if (SSL_use_PrivateKey(conn->ssl, pkey) != 1)
1145  {
1146  char *err = SSLerrmessage(ERR_get_error());
1147 
1149  libpq_gettext("could not load private SSL key \"%s\" from engine \"%s\": %s\n"),
1150  engine_colon, engine_str, err);
1151  SSLerrfree(err);
1152  ENGINE_finish(conn->engine);
1153  ENGINE_free(conn->engine);
1154  conn->engine = NULL;
1155  free(engine_str);
1156  return -1;
1157  }
1158 
1159  free(engine_str);
1160 
1161  fnbuf[0] = '\0'; /* indicate we're not going to load from a
1162  * file */
1163  }
1164  else
1165 #endif /* USE_SSL_ENGINE */
1166  {
1167  /* PGSSLKEY is not an engine, treat it as a filename */
1168  strlcpy(fnbuf, conn->sslkey, sizeof(fnbuf));
1169  }
1170  }
1171  else if (have_homedir)
1172  {
1173  /* No PGSSLKEY specified, load default file */
1174  snprintf(fnbuf, sizeof(fnbuf), "%s/%s", homedir, USER_KEY_FILE);
1175  }
1176  else
1177  fnbuf[0] = '\0';
1178 
1179  if (have_cert && fnbuf[0] != '\0')
1180  {
1181  /* read the client key from file */
1182 
1183  if (stat(fnbuf, &buf) != 0)
1184  {
1186  libpq_gettext("certificate present, but not private key file \"%s\"\n"),
1187  fnbuf);
1188  return -1;
1189  }
1190 #ifndef WIN32
1191  if (!S_ISREG(buf.st_mode) || buf.st_mode & (S_IRWXG | S_IRWXO))
1192  {
1194  libpq_gettext("private key file \"%s\" has group or world access; permissions should be u=rw (0600) or less\n"),
1195  fnbuf);
1196  return -1;
1197  }
1198 #endif
1199 
1200  if (SSL_use_PrivateKey_file(conn->ssl, fnbuf, SSL_FILETYPE_PEM) != 1)
1201  {
1202  char *err = SSLerrmessage(ERR_get_error());
1203 
1204  /*
1205  * We'll try to load the file in DER (binary ASN.1) format, and if
1206  * that fails too, report the original error. This could mask
1207  * issues where there's something wrong with a DER-format cert,
1208  * but we'd have to duplicate openssl's format detection to be
1209  * smarter than this. We can't just probe for a leading -----BEGIN
1210  * because PEM can have leading non-matching lines and blanks.
1211  * OpenSSL doesn't expose its get_name(...) and its PEM routines
1212  * don't differentiate between failure modes in enough detail to
1213  * let us tell the difference between "not PEM, try DER" and
1214  * "wrong password".
1215  */
1216  if (SSL_use_PrivateKey_file(conn->ssl, fnbuf, SSL_FILETYPE_ASN1) != 1)
1217  {
1219  libpq_gettext("could not load private key file \"%s\": %s\n"),
1220  fnbuf, err);
1221  SSLerrfree(err);
1222  return -1;
1223  }
1224 
1225  SSLerrfree(err);
1226 
1227  }
1228  }
1229 
1230  /* verify that the cert and key go together */
1231  if (have_cert &&
1232  SSL_check_private_key(conn->ssl) != 1)
1233  {
1234  char *err = SSLerrmessage(ERR_get_error());
1235 
1237  libpq_gettext("certificate does not match private key file \"%s\": %s\n"),
1238  fnbuf, err);
1239  SSLerrfree(err);
1240  return -1;
1241  }
1242 
1243  /*
1244  * If a root cert was loaded, also set our certificate verification
1245  * callback.
1246  */
1247  if (have_rootcert)
1248  SSL_set_verify(conn->ssl, SSL_VERIFY_PEER, verify_cb);
1249 
1250  /*
1251  * Set compression option if necessary.
1252  */
1253  if (conn->sslcompression && conn->sslcompression[0] == '0')
1254  SSL_set_options(conn->ssl, SSL_OP_NO_COMPRESSION);
1255  else
1256  SSL_clear_options(conn->ssl, SSL_OP_NO_COMPRESSION);
1257 
1258  return 0;
1259 }
1260 
1261 /*
1262  * Attempt to negotiate SSL connection.
1263  */
1266 {
1267  int r;
1268 
1269  ERR_clear_error();
1270  r = SSL_connect(conn->ssl);
1271  if (r <= 0)
1272  {
1273  int err = SSL_get_error(conn->ssl, r);
1274  unsigned long ecode;
1275 
1276  ecode = ERR_get_error();
1277  switch (err)
1278  {
1279  case SSL_ERROR_WANT_READ:
1280  return PGRES_POLLING_READING;
1281 
1282  case SSL_ERROR_WANT_WRITE:
1283  return PGRES_POLLING_WRITING;
1284 
1285  case SSL_ERROR_SYSCALL:
1286  {
1287  char sebuf[PG_STRERROR_R_BUFLEN];
1288 
1289  if (r == -1)
1291  libpq_gettext("SSL SYSCALL error: %s\n"),
1292  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
1293  else
1295  libpq_gettext("SSL SYSCALL error: EOF detected\n"));
1296  pgtls_close(conn);
1297  return PGRES_POLLING_FAILED;
1298  }
1299  case SSL_ERROR_SSL:
1300  {
1301  char *err = SSLerrmessage(ecode);
1302 
1304  libpq_gettext("SSL error: %s\n"),
1305  err);
1306  SSLerrfree(err);
1307  switch (ERR_GET_REASON(ecode))
1308  {
1309  /*
1310  * UNSUPPORTED_PROTOCOL, WRONG_VERSION_NUMBER, and
1311  * TLSV1_ALERT_PROTOCOL_VERSION have been observed
1312  * when trying to communicate with an old OpenSSL
1313  * library, or when the client and server specify
1314  * disjoint protocol ranges.
1315  * NO_PROTOCOLS_AVAILABLE occurs if there's a
1316  * local misconfiguration (which can happen
1317  * despite our checks, if openssl.cnf injects a
1318  * limit we didn't account for). It's not very
1319  * clear what would make OpenSSL return the other
1320  * codes listed here, but a hint about protocol
1321  * versions seems like it's appropriate for all.
1322  */
1323  case SSL_R_NO_PROTOCOLS_AVAILABLE:
1324  case SSL_R_UNSUPPORTED_PROTOCOL:
1325  case SSL_R_BAD_PROTOCOL_VERSION_NUMBER:
1326  case SSL_R_UNKNOWN_PROTOCOL:
1327  case SSL_R_UNKNOWN_SSL_VERSION:
1328  case SSL_R_UNSUPPORTED_SSL_VERSION:
1329  case SSL_R_WRONG_SSL_VERSION:
1330  case SSL_R_WRONG_VERSION_NUMBER:
1331  case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
1332 #ifdef SSL_R_VERSION_TOO_HIGH
1333  case SSL_R_VERSION_TOO_HIGH:
1334  case SSL_R_VERSION_TOO_LOW:
1335 #endif
1337  libpq_gettext("This may indicate that the server does not support any SSL protocol version between %s and %s.\n"),
1338  conn->ssl_min_protocol_version ?
1339  conn->ssl_min_protocol_version :
1340  MIN_OPENSSL_TLS_VERSION,
1341  conn->ssl_max_protocol_version ?
1342  conn->ssl_max_protocol_version :
1343  MAX_OPENSSL_TLS_VERSION);
1344  break;
1345  default:
1346  break;
1347  }
1348  pgtls_close(conn);
1349  return PGRES_POLLING_FAILED;
1350  }
1351 
1352  default:
1354  libpq_gettext("unrecognized SSL error code: %d\n"),
1355  err);
1356  pgtls_close(conn);
1357  return PGRES_POLLING_FAILED;
1358  }
1359  }
1360 
1361  /*
1362  * We already checked the server certificate in initialize_SSL() using
1363  * SSL_CTX_set_verify(), if root.crt exists.
1364  */
1365 
1366  /* get server certificate */
1367  conn->peer = SSL_get_peer_certificate(conn->ssl);
1368  if (conn->peer == NULL)
1369  {
1370  char *err = SSLerrmessage(ERR_get_error());
1371 
1373  libpq_gettext("certificate could not be obtained: %s\n"),
1374  err);
1375  SSLerrfree(err);
1376  pgtls_close(conn);
1377  return PGRES_POLLING_FAILED;
1378  }
1379 
1381  {
1382  pgtls_close(conn);
1383  return PGRES_POLLING_FAILED;
1384  }
1385 
1386  /* SSL handshake is complete */
1387  return PGRES_POLLING_OK;
1388 }
1389 
1390 void
1392 {
1393  bool destroy_needed = false;
1394 
1395  if (conn->ssl)
1396  {
1397  /*
1398  * We can't destroy everything SSL-related here due to the possible
1399  * later calls to OpenSSL routines which may need our thread
1400  * callbacks, so set a flag here and check at the end.
1401  */
1402  destroy_needed = true;
1403 
1404  SSL_shutdown(conn->ssl);
1405  SSL_free(conn->ssl);
1406  conn->ssl = NULL;
1407  conn->ssl_in_use = false;
1408  }
1409 
1410  if (conn->peer)
1411  {
1412  X509_free(conn->peer);
1413  conn->peer = NULL;
1414  }
1415 
1416 #ifdef USE_SSL_ENGINE
1417  if (conn->engine)
1418  {
1419  ENGINE_finish(conn->engine);
1420  ENGINE_free(conn->engine);
1421  conn->engine = NULL;
1422  }
1423 #endif
1424 
1425  /*
1426  * This will remove our SSL locking hooks, if this is the last SSL
1427  * connection, which means we must wait to call it until after all SSL
1428  * calls have been made, otherwise we can end up with a race condition and
1429  * possible deadlocks.
1430  *
1431  * See comments above destroy_ssl_system().
1432  */
1433  if (destroy_needed)
1435 }
1436 
1437 
1438 /*
1439  * Obtain reason string for passed SSL errcode
1440  *
1441  * ERR_get_error() is used by caller to get errcode to pass here.
1442  *
1443  * Some caution is needed here since ERR_reason_error_string will
1444  * return NULL if it doesn't recognize the error code. We don't
1445  * want to return NULL ever.
1446  */
1447 static char ssl_nomem[] = "out of memory allocating error description";
1448 
1449 #define SSL_ERR_LEN 128
1450 
1451 static char *
1452 SSLerrmessage(unsigned long ecode)
1453 {
1454  const char *errreason;
1455  char *errbuf;
1456 
1457  errbuf = malloc(SSL_ERR_LEN);
1458  if (!errbuf)
1459  return ssl_nomem;
1460  if (ecode == 0)
1461  {
1462  snprintf(errbuf, SSL_ERR_LEN, libpq_gettext("no SSL error reported"));
1463  return errbuf;
1464  }
1465  errreason = ERR_reason_error_string(ecode);
1466  if (errreason != NULL)
1467  {
1468  strlcpy(errbuf, errreason, SSL_ERR_LEN);
1469  return errbuf;
1470  }
1471  snprintf(errbuf, SSL_ERR_LEN, libpq_gettext("SSL error code %lu"), ecode);
1472  return errbuf;
1473 }
1474 
1475 static void
1477 {
1478  if (buf != ssl_nomem)
1479  free(buf);
1480 }
1481 
1482 /* ------------------------------------------------------------ */
1483 /* SSL information functions */
1484 /* ------------------------------------------------------------ */
1485 
1486 /*
1487  * Return pointer to OpenSSL object.
1488  */
1489 void *
1491 {
1492  if (!conn)
1493  return NULL;
1494  return conn->ssl;
1495 }
1496 
1497 void *
1498 PQsslStruct(PGconn *conn, const char *struct_name)
1499 {
1500  if (!conn)
1501  return NULL;
1502  if (strcmp(struct_name, "OpenSSL") == 0)
1503  return conn->ssl;
1504  return NULL;
1505 }
1506 
1507 const char *const *
1509 {
1510  static const char *const result[] = {
1511  "library",
1512  "key_bits",
1513  "cipher",
1514  "compression",
1515  "protocol",
1516  NULL
1517  };
1518 
1519  return result;
1520 }
1521 
1522 const char *
1523 PQsslAttribute(PGconn *conn, const char *attribute_name)
1524 {
1525  if (!conn)
1526  return NULL;
1527  if (conn->ssl == NULL)
1528  return NULL;
1529 
1530  if (strcmp(attribute_name, "library") == 0)
1531  return "OpenSSL";
1532 
1533  if (strcmp(attribute_name, "key_bits") == 0)
1534  {
1535  static char sslbits_str[12];
1536  int sslbits;
1537 
1538  SSL_get_cipher_bits(conn->ssl, &sslbits);
1539  snprintf(sslbits_str, sizeof(sslbits_str), "%d", sslbits);
1540  return sslbits_str;
1541  }
1542 
1543  if (strcmp(attribute_name, "cipher") == 0)
1544  return SSL_get_cipher(conn->ssl);
1545 
1546  if (strcmp(attribute_name, "compression") == 0)
1547  return SSL_get_current_compression(conn->ssl) ? "on" : "off";
1548 
1549  if (strcmp(attribute_name, "protocol") == 0)
1550  return SSL_get_version(conn->ssl);
1551 
1552  return NULL; /* unknown attribute */
1553 }
1554 
1555 /*
1556  * Private substitute BIO: this does the sending and receiving using
1557  * pqsecure_raw_write() and pqsecure_raw_read() instead, to allow those
1558  * functions to disable SIGPIPE and give better error messages on I/O errors.
1559  *
1560  * These functions are closely modelled on the standard socket BIO in OpenSSL;
1561  * see sock_read() and sock_write() in OpenSSL's crypto/bio/bss_sock.c.
1562  * XXX OpenSSL 1.0.1e considers many more errcodes than just EINTR as reasons
1563  * to retry; do we need to adopt their logic for that?
1564  */
1565 
1566 #ifndef HAVE_BIO_GET_DATA
1567 #define BIO_get_data(bio) (bio->ptr)
1568 #define BIO_set_data(bio, data) (bio->ptr = data)
1569 #endif
1570 
1571 static BIO_METHOD *my_bio_methods;
1572 
1573 static int
1574 my_sock_read(BIO *h, char *buf, int size)
1575 {
1576  int res;
1577 
1578  res = pqsecure_raw_read((PGconn *) BIO_get_data(h), buf, size);
1579  BIO_clear_retry_flags(h);
1580  if (res < 0)
1581  {
1582  /* If we were interrupted, tell caller to retry */
1583  switch (SOCK_ERRNO)
1584  {
1585 #ifdef EAGAIN
1586  case EAGAIN:
1587 #endif
1588 #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
1589  case EWOULDBLOCK:
1590 #endif
1591  case EINTR:
1592  BIO_set_retry_read(h);
1593  break;
1594 
1595  default:
1596  break;
1597  }
1598  }
1599 
1600  return res;
1601 }
1602 
1603 static int
1604 my_sock_write(BIO *h, const char *buf, int size)
1605 {
1606  int res;
1607 
1608  res = pqsecure_raw_write((PGconn *) BIO_get_data(h), buf, size);
1609  BIO_clear_retry_flags(h);
1610  if (res <= 0)
1611  {
1612  /* If we were interrupted, tell caller to retry */
1613  switch (SOCK_ERRNO)
1614  {
1615 #ifdef EAGAIN
1616  case EAGAIN:
1617 #endif
1618 #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
1619  case EWOULDBLOCK:
1620 #endif
1621  case EINTR:
1622  BIO_set_retry_write(h);
1623  break;
1624 
1625  default:
1626  break;
1627  }
1628  }
1629 
1630  return res;
1631 }
1632 
1633 static BIO_METHOD *
1635 {
1636  if (!my_bio_methods)
1637  {
1638  BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
1639 #ifdef HAVE_BIO_METH_NEW
1640  int my_bio_index;
1641 
1642  my_bio_index = BIO_get_new_index();
1643  if (my_bio_index == -1)
1644  return NULL;
1645  my_bio_methods = BIO_meth_new(my_bio_index, "libpq socket");
1646  if (!my_bio_methods)
1647  return NULL;
1648 
1649  /*
1650  * As of this writing, these functions never fail. But check anyway,
1651  * like OpenSSL's own examples do.
1652  */
1653  if (!BIO_meth_set_write(my_bio_methods, my_sock_write) ||
1654  !BIO_meth_set_read(my_bio_methods, my_sock_read) ||
1655  !BIO_meth_set_gets(my_bio_methods, BIO_meth_get_gets(biom)) ||
1656  !BIO_meth_set_puts(my_bio_methods, BIO_meth_get_puts(biom)) ||
1657  !BIO_meth_set_ctrl(my_bio_methods, BIO_meth_get_ctrl(biom)) ||
1658  !BIO_meth_set_create(my_bio_methods, BIO_meth_get_create(biom)) ||
1659  !BIO_meth_set_destroy(my_bio_methods, BIO_meth_get_destroy(biom)) ||
1660  !BIO_meth_set_callback_ctrl(my_bio_methods, BIO_meth_get_callback_ctrl(biom)))
1661  {
1662  BIO_meth_free(my_bio_methods);
1663  my_bio_methods = NULL;
1664  return NULL;
1665  }
1666 #else
1667  my_bio_methods = malloc(sizeof(BIO_METHOD));
1668  if (!my_bio_methods)
1669  return NULL;
1670  memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
1671  my_bio_methods->bread = my_sock_read;
1672  my_bio_methods->bwrite = my_sock_write;
1673 #endif
1674  }
1675  return my_bio_methods;
1676 }
1677 
1678 /* This should exactly match OpenSSL's SSL_set_fd except for using my BIO */
1679 static int
1681 {
1682  int ret = 0;
1683  BIO *bio;
1684  BIO_METHOD *bio_method;
1685 
1686  bio_method = my_BIO_s_socket();
1687  if (bio_method == NULL)
1688  {
1689  SSLerr(SSL_F_SSL_SET_FD, ERR_R_BUF_LIB);
1690  goto err;
1691  }
1692  bio = BIO_new(bio_method);
1693  if (bio == NULL)
1694  {
1695  SSLerr(SSL_F_SSL_SET_FD, ERR_R_BUF_LIB);
1696  goto err;
1697  }
1698  BIO_set_data(bio, conn);
1699 
1700  SSL_set_bio(conn->ssl, bio, bio);
1701  BIO_set_fd(bio, fd, BIO_NOCLOSE);
1702  ret = 1;
1703 err:
1704  return ret;
1705 }
1706 
1707 /*
1708  * This is the default handler to return a client cert password from
1709  * conn->sslpassword. Apps may install it explicitly if they want to
1710  * prevent openssl from ever prompting on stdin.
1711  */
1712 int
1714 {
1715  if (conn->sslpassword)
1716  {
1717  if (strlen(conn->sslpassword) + 1 > size)
1718  fprintf(stderr, libpq_gettext("WARNING: sslpassword truncated\n"));
1719  strncpy(buf, conn->sslpassword, size);
1720  buf[size - 1] = '\0';
1721  return strlen(buf);
1722  }
1723  else
1724  {
1725  buf[0] = '\0';
1726  return 0;
1727  }
1728 }
1729 
1732 {
1733  return PQsslKeyPassHook;
1734 }
1735 
1736 void
1738 {
1739  PQsslKeyPassHook = hook;
1740 }
1741 
1742 /*
1743  * Supply a password to decrypt a client certificate.
1744  *
1745  * This must match OpenSSL type pem_password_cb.
1746  */
1747 static int
1748 PQssl_passwd_cb(char *buf, int size, int rwflag, void *userdata)
1749 {
1750  PGconn *conn = userdata;
1751 
1752  if (PQsslKeyPassHook)
1753  return PQsslKeyPassHook(buf, size, conn);
1754  else
1755  return PQdefaultSSLKeyPassHook_OpenSSL(buf, size, conn);
1756 }
1757 
1758 /*
1759  * Convert TLS protocol version string to OpenSSL values
1760  *
1761  * If a version is passed that is not supported by the current OpenSSL version,
1762  * then we return -1. If a non-negative value is returned, subsequent code can
1763  * assume it is working with a supported version.
1764  *
1765  * Note: this is rather similar to the backend routine in be-secure-openssl.c,
1766  * so make sure to update both routines if changing this one.
1767  */
1768 static int
1769 ssl_protocol_version_to_openssl(const char *protocol)
1770 {
1771  if (pg_strcasecmp("TLSv1", protocol) == 0)
1772  return TLS1_VERSION;
1773 
1774 #ifdef TLS1_1_VERSION
1775  if (pg_strcasecmp("TLSv1.1", protocol) == 0)
1776  return TLS1_1_VERSION;
1777 #endif
1778 
1779 #ifdef TLS1_2_VERSION
1780  if (pg_strcasecmp("TLSv1.2", protocol) == 0)
1781  return TLS1_2_VERSION;
1782 #endif
1783 
1784 #ifdef TLS1_3_VERSION
1785  if (pg_strcasecmp("TLSv1.3", protocol) == 0)
1786  return TLS1_3_VERSION;
1787 #endif
1788 
1789  return -1;
1790 }
static bool pq_init_ssl_lib
CRITICAL_SECTION * pthread_mutex_t
Definition: pthread-win32.h:8
static PgChecksumMode mode
Definition: pg_checksums.c:61
void * PQgetssl(PGconn *conn)
static int my_sock_write(BIO *h, const char *buf, int size)
void printfPQExpBuffer(PQExpBuffer str, const char *fmt,...)
Definition: pqexpbuffer.c:237
const char * PQsslAttribute(PGconn *conn, const char *attribute_name)
int pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn, int *names_examined, char **first_name)
#define EAGAIN
Definition: win32_port.h:341
static PostgresPollingStatusType open_client_SSL(PGconn *)
void * PQsslStruct(PGconn *conn, const char *struct_name)
#define PG_STRERROR_R_BUFLEN
Definition: port.h:233
int PQdefaultSSLKeyPassHook_OpenSSL(char *buf, int size, PGconn *conn)
int pthread_mutex_init(pthread_mutex_t *mp, void *attr)
Definition: pthread-win32.c:35
char * ssl_min_protocol_version
Definition: libpq-int.h:370
int pg_strcasecmp(const char *s1, const char *s2)
Definition: pgstrcasecmp.c:36
ssize_t pqsecure_raw_read(PGconn *conn, void *ptr, size_t len)
Definition: fe-secure.c:239
PostgresPollingStatusType pgtls_open_client(PGconn *conn)
#define fprintf
Definition: port.h:219
#define BIO_set_data(bio, data)
static int fd(const char *x, int i)
Definition: preproc-init.c:105
static PQsslKeyPassHook_OpenSSL_type PQsslKeyPassHook
static int openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *name, char **store_name)
static int PQssl_passwd_cb(char *buf, int size, int rwflag, void *userdata)
#define malloc(a)
Definition: header.h:50
char * sslkey
Definition: libpq-int.h:360
DWORD pthread_self(void)
Definition: pthread-win32.c:18
#define SOCK_STRERROR
Definition: libpq-int.h:819
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Definition: libpq-int.h:359
#define SOCK_ERRNO
Definition: libpq-int.h:818
PGconn * conn
Definition: streamutil.c:54
#define MAXPGPATH
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Definition: pqexpbuffer.c:267
static char ssl_nomem[]
bool ssl_in_use
Definition: libpq-int.h:472
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Definition: pthread-win32.c:45
static char * buf
Definition: pg_test_fsync.c:68
bool pgtls_read_pending(PGconn *conn)
#define S_IRWXG
Definition: win32_port.h:301
bool pq_verify_peer_name_matches_certificate(PGconn *conn)
void PQsetSSLKeyPassHook_OpenSSL(PQsslKeyPassHook_OpenSSL_type hook)
char * sslpassword
Definition: libpq-int.h:362
static BIO_METHOD * my_bio_methods
static int initialize_SSL(PGconn *conn)
#define SOCK_ERRNO_SET(e)
Definition: libpq-int.h:820
const char *const * PQsslAttributeNames(PGconn *conn)
static int verify_cb(int ok, X509_STORE_CTX *ctx)
pgsocket sock
Definition: libpq-int.h:410
#define S_ISREG(m)
Definition: win32_port.h:319
static int my_sock_read(BIO *h, char *buf, int size)
static int my_SSL_set_fd(PGconn *conn, int fd)
static void SSLerrfree(char *buf)
void pgtls_close(PGconn *conn)
ssize_t pgtls_read(PGconn *conn, void *ptr, size_t len)
ssize_t pgtls_write(PGconn *conn, const void *ptr, size_t len)
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Definition: pthread-win32.c:54
unsigned short st_mode
Definition: win32_port.h:260
char * sslmode
Definition: libpq-int.h:358
static bool pq_init_crypto_lib
int pq_verify_peer_name_matches_certificate_name(PGconn *conn, const char *namedata, size_t namelen, char **store_name)
PQExpBufferData errorMessage
Definition: libpq-int.h:526
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Definition: libpq-int.h:361
#define free(a)
Definition: header.h:65
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
int SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
static int ssl_protocol_version_to_openssl(const char *protocol)
#define strerror_r
Definition: port.h:232
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Definition: libpq-int.h:363
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Definition: fe-secure.c:321
#define ECONNRESET
Definition: win32_port.h:353
PQsslKeyPassHook_OpenSSL_type PQgetSSLKeyPassHook_OpenSSL(void)
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Definition: encode.c:561
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Definition: libpq-fe.h:74
static char * SSLerrmessage(unsigned long ecode)
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Definition: fe-connect.c:7175
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#define EWOULDBLOCK
Definition: win32_port.h:349
#define EINTR
Definition: win32_port.h:343
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int SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
int(* PQsslKeyPassHook_OpenSSL_type)(char *buf, int size, PGconn *conn)
Definition: libpq-fe.h:623
static void destroy_ssl_system(void)
static unsigned hash(unsigned *uv, int n)
Definition: rege_dfa.c:541
#define snprintf
Definition: port.h:215
static BIO_METHOD * my_BIO_s_socket(void)
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#define SSL_ERR_LEN
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#define S_IRWXO
Definition: win32_port.h:313
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Definition: libpq-int.h:805
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