1 /*-------------------------------------------------------------------------
4 * functions related to setting up a secure connection to the frontend.
5 * Secure connections are expected to provide confidentiality,
6 * message integrity and endpoint authentication.
9 * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
10 * Portions Copyright (c) 1994, Regents of the University of California
14 * $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.71 2006/07/14 14:52:19 momjian Exp $
16 * Since the server static private key ($DataDir/server.key)
17 * will normally be stored unencrypted so that the database
18 * backend can restart automatically, it is important that
19 * we select an algorithm that continues to provide confidentiality
20 * even if the attacker has the server's private key. Empheral
21 * DH (EDH) keys provide this, and in fact provide Perfect Forward
22 * Secrecy (PFS) except for situations where the session can
23 * be hijacked during a periodic handshake/renegotiation.
24 * Even that backdoor can be closed if client certificates
25 * are used (since the imposter will be unable to successfully
26 * complete renegotiation).
28 * N.B., the static private key should still be protected to
29 * the largest extent possible, to minimize the risk of
32 * Another benefit of EDH is that it allows the backend and
33 * clients to use DSA keys. DSA keys can only provide digital
34 * signatures, not encryption, and are often acceptable in
35 * jurisdictions where RSA keys are unacceptable.
37 * The downside to EDH is that it makes it impossible to
38 * use ssldump(1) if there's a problem establishing an SSL
39 * session. In this case you'll need to temporarily disable
40 * EDH by commenting out the callback.
44 * Because the risk of cryptanalysis increases as large
45 * amounts of data are sent with the same session key, the
46 * session keys are periodically renegotiated.
49 * milestone 1: fix basic coding errors
50 * [*] existing SSL code pulled out of existing files.
51 * [*] SSL_get_error() after SSL_read() and SSL_write(),
52 * SSL_shutdown(), default to TLSv1.
54 * milestone 2: provide endpoint authentication (server)
55 * [*] client verifies server cert
56 * [*] client verifies server hostname
58 * milestone 3: improve confidentially, support perfect forward secrecy
59 * [ ] use 'random' file, read from '/dev/urandom?'
60 * [*] emphermal DH keys, default values
61 * [*] periodic renegotiation
62 * [*] private key permissions
64 * milestone 4: provide endpoint authentication (client)
65 * [*] server verifies client certificates
67 * milestone 5: provide informational callbacks
68 * [*] provide informational callbacks
72 * [ ] more informative psql
74 *-------------------------------------------------------------------------
83 #include <sys/socket.h>
86 #include <netinet/in.h>
87 #ifdef HAVE_NETINET_TCP_H
88 #include <netinet/tcp.h>
89 #include <arpa/inet.h>
93 #include <openssl/ssl.h>
94 #include <openssl/dh.h>
97 #include "libpq/libpq.h"
98 #include "tcop/tcopprot.h"
103 #define ROOT_CERT_FILE "root.crt"
104 #define ROOT_CRL_FILE "root.crl"
105 #define SERVER_CERT_FILE "server.crt"
106 #define SERVER_PRIVATE_KEY_FILE "server.key"
108 static DH *load_dh_file(int keylength);
109 static DH *load_dh_buffer(const char *, size_t);
110 static DH *tmp_dh_cb(SSL *s, int is_export, int keylength);
111 static int verify_cb(int, X509_STORE_CTX *);
112 static void info_cb(const SSL *ssl, int type, int args);
113 static void initialize_SSL(void);
114 static void destroy_SSL(void);
115 static int open_server_SSL(Port *);
116 static void close_SSL(Port *);
117 static const char *SSLerrmessage(void);
122 * How much data can be sent across a secure connection
123 * (total in both directions) before we require renegotiation.
125 #define RENEGOTIATION_LIMIT (512 * 1024 * 1024)
127 static SSL_CTX *SSL_context = NULL;
130 /* ------------------------------------------------------------ */
131 /* Hardcoded values */
132 /* ------------------------------------------------------------ */
135 * Hardcoded DH parameters, used in empheral DH keying.
136 * As discussed above, EDH protects the confidentiality of
137 * sessions even if the static private key is compromised,
138 * so we are *highly* motivated to ensure that we can use
139 * EDH even if the DBA... or an attacker... deletes the
140 * $DataDir/dh*.pem files.
142 * We could refuse SSL connections unless a good DH parameter
143 * file exists, but some clients may quietly renegotiate an
144 * unsecured connection without fully informing the user.
147 * Alternately, the backend could attempt to load these files
148 * on startup if SSL is enabled - and refuse to start if any
149 * do not exist - but this would tend to piss off DBAs.
151 * If you want to create your own hardcoded DH parameters
152 * for fun and profit, review "Assigned Number for SKIP
153 * Protocols" (http://www.skip-vpn.org/spec/numbers.html)
158 static const char file_dh512[] =
159 "-----BEGIN DH PARAMETERS-----\n\
160 MEYCQQD1Kv884bEpQBgRjXyEpwpy1obEAxnIByl6ypUM2Zafq9AKUJsCRtMIPWak\n\
161 XUGfnHy9iUsiGSa6q6Jew1XpKgVfAgEC\n\
162 -----END DH PARAMETERS-----\n";
164 static const char file_dh1024[] =
165 "-----BEGIN DH PARAMETERS-----\n\
166 MIGHAoGBAPSI/VhOSdvNILSd5JEHNmszbDgNRR0PfIizHHxbLY7288kjwEPwpVsY\n\
167 jY67VYy4XTjTNP18F1dDox0YbN4zISy1Kv884bEpQBgRjXyEpwpy1obEAxnIByl6\n\
168 ypUM2Zafq9AKUJsCRtMIPWakXUGfnHy9iUsiGSa6q6Jew1XpL3jHAgEC\n\
169 -----END DH PARAMETERS-----\n";
171 static const char file_dh2048[] =
172 "-----BEGIN DH PARAMETERS-----\n\
173 MIIBCAKCAQEA9kJXtwh/CBdyorrWqULzBej5UxE5T7bxbrlLOCDaAadWoxTpj0BV\n\
174 89AHxstDqZSt90xkhkn4DIO9ZekX1KHTUPj1WV/cdlJPPT2N286Z4VeSWc39uK50\n\
175 T8X8dryDxUcwYc58yWb/Ffm7/ZFexwGq01uejaClcjrUGvC/RgBYK+X0iP1YTknb\n\
176 zSC0neSRBzZrM2w4DUUdD3yIsxx8Wy2O9vPJI8BD8KVbGI2Ou1WMuF040zT9fBdX\n\
177 Q6MdGGzeMyEstSr/POGxKUAYEY18hKcKctaGxAMZyAcpesqVDNmWn6vQClCbAkbT\n\
178 CD1mpF1Bn5x8vYlLIhkmuquiXsNV6TILOwIBAg==\n\
179 -----END DH PARAMETERS-----\n";
181 static const char file_dh4096[] =
182 "-----BEGIN DH PARAMETERS-----\n\
183 MIICCAKCAgEA+hRyUsFN4VpJ1O8JLcCo/VWr19k3BCgJ4uk+d+KhehjdRqNDNyOQ\n\
184 l/MOyQNQfWXPeGKmOmIig6Ev/nm6Nf9Z2B1h3R4hExf+zTiHnvVPeRBhjdQi81rt\n\
185 Xeoh6TNrSBIKIHfUJWBh3va0TxxjQIs6IZOLeVNRLMqzeylWqMf49HsIXqbcokUS\n\
186 Vt1BkvLdW48j8PPv5DsKRN3tloTxqDJGo9tKvj1Fuk74A+Xda1kNhB7KFlqMyN98\n\
187 VETEJ6c7KpfOo30mnK30wqw3S8OtaIR/maYX72tGOno2ehFDkq3pnPtEbD2CScxc\n\
188 alJC+EL7RPk5c/tgeTvCngvc1KZn92Y//EI7G9tPZtylj2b56sHtMftIoYJ9+ODM\n\
189 sccD5Piz/rejE3Ome8EOOceUSCYAhXn8b3qvxVI1ddd1pED6FHRhFvLrZxFvBEM9\n\
190 ERRMp5QqOaHJkM+Dxv8Cj6MqrCbfC4u+ZErxodzuusgDgvZiLF22uxMZbobFWyte\n\
191 OvOzKGtwcTqO/1wV5gKkzu1ZVswVUQd5Gg8lJicwqRWyyNRczDDoG9jVDxmogKTH\n\
192 AaqLulO7R8Ifa1SwF2DteSGVtgWEN8gDpN3RBmmPTDngyF2DHb5qmpnznwtFKdTL\n\
193 KWbuHn491xNO25CQWMtem80uKw+pTnisBRF/454n1Jnhub144YRBoN8CAQI=\n\
194 -----END DH PARAMETERS-----\n";
197 /* ------------------------------------------------------------ */
198 /* Procedures common to all secure sessions */
199 /* ------------------------------------------------------------ */
202 * Initialize global context
205 secure_initialize(void)
215 * Destroy global context
226 * Attempt to negotiate secure session.
229 secure_open_server(Port *port)
234 r = open_server_SSL(port);
241 * Close secure session.
244 secure_close(Port *port)
253 * Read data from a secure connection.
256 secure_read(Port *port, void *ptr, size_t len)
266 n = SSL_read(port->ssl, ptr, len);
267 err = SSL_get_error(port->ssl, n);
273 case SSL_ERROR_WANT_READ:
274 case SSL_ERROR_WANT_WRITE:
276 pgwin32_waitforsinglesocket(SSL_get_fd(port->ssl),
277 (err == SSL_ERROR_WANT_READ) ?
278 FD_READ | FD_CLOSE : FD_WRITE | FD_CLOSE);
281 case SSL_ERROR_SYSCALL:
284 (errcode_for_socket_access(),
285 errmsg("SSL SYSCALL error: %m")));
289 (errcode(ERRCODE_PROTOCOL_VIOLATION),
290 errmsg("SSL SYSCALL error: EOF detected")));
297 (errcode(ERRCODE_PROTOCOL_VIOLATION),
298 errmsg("SSL error: %s", SSLerrmessage())));
300 case SSL_ERROR_ZERO_RETURN:
306 (errcode(ERRCODE_PROTOCOL_VIOLATION),
307 errmsg("unrecognized SSL error code: %d",
316 prepare_for_client_read();
318 n = recv(port->sock, ptr, len, 0);
327 * Write data to a secure connection.
330 secure_write(Port *port, void *ptr, size_t len)
339 if (port->count > RENEGOTIATION_LIMIT)
341 SSL_set_session_id_context(port->ssl, (void *) &SSL_context,
342 sizeof(SSL_context));
343 if (SSL_renegotiate(port->ssl) <= 0)
345 (errcode(ERRCODE_PROTOCOL_VIOLATION),
346 errmsg("SSL renegotiation failure")));
347 if (SSL_do_handshake(port->ssl) <= 0)
349 (errcode(ERRCODE_PROTOCOL_VIOLATION),
350 errmsg("SSL renegotiation failure")));
351 if (port->ssl->state != SSL_ST_OK)
353 (errcode(ERRCODE_PROTOCOL_VIOLATION),
354 errmsg("SSL failed to send renegotiation request")));
355 port->ssl->state |= SSL_ST_ACCEPT;
356 SSL_do_handshake(port->ssl);
357 if (port->ssl->state != SSL_ST_OK)
359 (errcode(ERRCODE_PROTOCOL_VIOLATION),
360 errmsg("SSL renegotiation failure")));
365 n = SSL_write(port->ssl, ptr, len);
366 err = SSL_get_error(port->ssl, n);
372 case SSL_ERROR_WANT_READ:
373 case SSL_ERROR_WANT_WRITE:
375 pgwin32_waitforsinglesocket(SSL_get_fd(port->ssl),
376 (err == SSL_ERROR_WANT_READ) ?
377 FD_READ | FD_CLOSE : FD_WRITE | FD_CLOSE);
380 case SSL_ERROR_SYSCALL:
383 (errcode_for_socket_access(),
384 errmsg("SSL SYSCALL error: %m")));
388 (errcode(ERRCODE_PROTOCOL_VIOLATION),
389 errmsg("SSL SYSCALL error: EOF detected")));
396 (errcode(ERRCODE_PROTOCOL_VIOLATION),
397 errmsg("SSL error: %s", SSLerrmessage())));
399 case SSL_ERROR_ZERO_RETURN:
405 (errcode(ERRCODE_PROTOCOL_VIOLATION),
406 errmsg("unrecognized SSL error code: %d",
414 n = send(port->sock, ptr, len, 0);
419 /* ------------------------------------------------------------ */
420 /* SSL specific code */
421 /* ------------------------------------------------------------ */
425 * Private substitute BIO: this wraps the SSL library's standard socket BIO
426 * so that we can enable and disable interrupts just while calling recv().
427 * We cannot have interrupts occurring while the bulk of openssl runs,
428 * because it uses malloc() and possibly other non-reentrant libc facilities.
430 * As of openssl 0.9.7, we can use the reasonably clean method of interposing
431 * a wrapper around the standard socket BIO's sock_read() method. This relies
432 * on the fact that sock_read() doesn't call anything non-reentrant, in fact
433 * not much of anything at all except recv(). If this ever changes we'd
434 * probably need to duplicate the code of sock_read() in order to push the
435 * interrupt enable/disable down yet another level.
438 static bool my_bio_initialized = false;
439 static BIO_METHOD my_bio_methods;
440 static int (*std_sock_read) (BIO *h, char *buf, int size);
443 my_sock_read(BIO *h, char *buf, int size)
447 prepare_for_client_read();
449 res = std_sock_read(h, buf, size);
457 my_BIO_s_socket(void)
459 if (!my_bio_initialized)
461 memcpy(&my_bio_methods, BIO_s_socket(), sizeof(BIO_METHOD));
462 std_sock_read = my_bio_methods.bread;
463 my_bio_methods.bread = my_sock_read;
464 my_bio_initialized = true;
466 return &my_bio_methods;
469 /* This should exactly match openssl's SSL_set_fd except for using my BIO */
471 my_SSL_set_fd(SSL *s, int fd)
476 bio = BIO_new(my_BIO_s_socket());
480 SSLerr(SSL_F_SSL_SET_FD, ERR_R_BUF_LIB);
483 BIO_set_fd(bio, fd, BIO_NOCLOSE);
484 SSL_set_bio(s, bio, bio);
491 * Load precomputed DH parameters.
493 * To prevent "downgrade" attacks, we perform a number of checks
494 * to verify that the DBA-generated DH parameters file contains
495 * what we expect it to contain.
498 load_dh_file(int keylength)
501 char fnbuf[MAXPGPATH];
505 /* attempt to open file. It's not an error if it doesn't exist. */
506 snprintf(fnbuf, sizeof(fnbuf), "dh%d.pem", keylength);
507 if ((fp = fopen(fnbuf, "r")) == NULL)
510 /* flock(fileno(fp), LOCK_SH); */
511 dh = PEM_read_DHparams(fp, NULL, NULL, NULL);
512 /* flock(fileno(fp), LOCK_UN); */
515 /* is the prime the correct size? */
516 if (dh != NULL && 8 * DH_size(dh) < keylength)
518 elog(LOG, "DH errors (%s): %d bits expected, %d bits found",
519 fnbuf, keylength, 8 * DH_size(dh));
523 /* make sure the DH parameters are usable */
526 if (DH_check(dh, &codes) == 0)
528 elog(LOG, "DH_check error (%s): %s", fnbuf, SSLerrmessage());
531 if (codes & DH_CHECK_P_NOT_PRIME)
533 elog(LOG, "DH error (%s): p is not prime", fnbuf);
536 if ((codes & DH_NOT_SUITABLE_GENERATOR) &&
537 (codes & DH_CHECK_P_NOT_SAFE_PRIME))
540 "DH error (%s): neither suitable generator or safe prime",
550 * Load hardcoded DH parameters.
552 * To prevent problems if the DH parameters files don't even
553 * exist, we can load DH parameters hardcoded into this file.
556 load_dh_buffer(const char *buffer, size_t len)
561 bio = BIO_new_mem_buf((char *) buffer, len);
564 dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
567 (errmsg_internal("DH load buffer: %s",
575 * Generate an empheral DH key. Because this can take a long
576 * time to compute, we can use precomputed parameters of the
579 * Since few sites will bother to precompute these parameter
580 * files, we also provide a fallback to the parameters provided
581 * by the OpenSSL project.
583 * These values can be static (once loaded or computed) since
584 * the OpenSSL library can efficiently generate random keys from
585 * the information provided.
588 tmp_dh_cb(SSL *s, int is_export, int keylength)
591 static DH *dh = NULL;
592 static DH *dh512 = NULL;
593 static DH *dh1024 = NULL;
594 static DH *dh2048 = NULL;
595 static DH *dh4096 = NULL;
601 dh512 = load_dh_file(keylength);
603 dh512 = load_dh_buffer(file_dh512, sizeof file_dh512);
609 dh1024 = load_dh_file(keylength);
611 dh1024 = load_dh_buffer(file_dh1024, sizeof file_dh1024);
617 dh2048 = load_dh_file(keylength);
619 dh2048 = load_dh_buffer(file_dh2048, sizeof file_dh2048);
625 dh4096 = load_dh_file(keylength);
627 dh4096 = load_dh_buffer(file_dh4096, sizeof file_dh4096);
633 dh = load_dh_file(keylength);
637 /* this may take a long time, but it may be necessary... */
638 if (r == NULL || 8 * DH_size(r) < keylength)
641 (errmsg_internal("DH: generating parameters (%d bits)....",
643 r = DH_generate_parameters(keylength, DH_GENERATOR_2, NULL, NULL);
650 * Certificate verification callback
652 * This callback allows us to log intermediate problems during
653 * verification, but for now we'll see if the final error message
654 * contains enough information.
656 * This callback also allows us to override the default acceptance
657 * criteria (e.g., accepting self-signed or expired certs), but
658 * for now we accept the default checks.
661 verify_cb(int ok, X509_STORE_CTX *ctx)
667 * This callback is used to copy SSL information messages
668 * into the PostgreSQL log.
671 info_cb(const SSL *ssl, int type, int args)
675 case SSL_CB_HANDSHAKE_START:
677 (errmsg_internal("SSL: handshake start")));
679 case SSL_CB_HANDSHAKE_DONE:
681 (errmsg_internal("SSL: handshake done")));
683 case SSL_CB_ACCEPT_LOOP:
685 (errmsg_internal("SSL: accept loop")));
687 case SSL_CB_ACCEPT_EXIT:
689 (errmsg_internal("SSL: accept exit (%d)", args)));
691 case SSL_CB_CONNECT_LOOP:
693 (errmsg_internal("SSL: connect loop")));
695 case SSL_CB_CONNECT_EXIT:
697 (errmsg_internal("SSL: connect exit (%d)", args)));
699 case SSL_CB_READ_ALERT:
701 (errmsg_internal("SSL: read alert (0x%04x)", args)));
703 case SSL_CB_WRITE_ALERT:
705 (errmsg_internal("SSL: write alert (0x%04x)", args)));
711 * Initialize global SSL context.
721 SSL_load_error_strings();
722 SSL_context = SSL_CTX_new(SSLv23_method());
725 (errmsg("could not create SSL context: %s",
729 * Load and verify certificate and private key
731 if (!SSL_CTX_use_certificate_file(SSL_context,
735 (errcode(ERRCODE_CONFIG_FILE_ERROR),
736 errmsg("could not load server certificate file \"%s\": %s",
737 SERVER_CERT_FILE, SSLerrmessage())));
739 if (stat(SERVER_PRIVATE_KEY_FILE, &buf) == -1)
741 (errcode_for_file_access(),
742 errmsg("could not access private key file \"%s\": %m",
743 SERVER_PRIVATE_KEY_FILE)));
746 * Require no public access to key file.
748 * XXX temporarily suppress check when on Windows, because there may
749 * not be proper support for Unix-y file permissions. Need to think
750 * of a reasonable check to apply on Windows. (See also the data
751 * directory permission check in postmaster.c)
753 #if !defined(WIN32) && !defined(__CYGWIN__)
754 if (!S_ISREG(buf.st_mode) || (buf.st_mode & (S_IRWXG | S_IRWXO)) ||
755 buf.st_uid != geteuid())
757 (errcode(ERRCODE_CONFIG_FILE_ERROR),
758 errmsg("unsafe permissions on private key file \"%s\"",
759 SERVER_PRIVATE_KEY_FILE),
760 errdetail("File must be owned by the database user and must have no permissions for \"group\" or \"other\".")));
763 if (!SSL_CTX_use_PrivateKey_file(SSL_context,
764 SERVER_PRIVATE_KEY_FILE,
767 (errmsg("could not load private key file \"%s\": %s",
768 SERVER_PRIVATE_KEY_FILE, SSLerrmessage())));
770 if (!SSL_CTX_check_private_key(SSL_context))
772 (errmsg("check of private key failed: %s",
776 /* set up empheral DH keys */
777 SSL_CTX_set_tmp_dh_callback(SSL_context, tmp_dh_cb);
778 SSL_CTX_set_options(SSL_context, SSL_OP_SINGLE_DH_USE | SSL_OP_NO_SSLv2);
780 /* setup the allowed cipher list */
781 if (SSL_CTX_set_cipher_list(SSL_context, "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH") != 1)
782 elog(FATAL, "could not set the cipher list (no valid ciphers available)");
785 * Require and check client certificates only if we have a root.crt file.
787 if (!SSL_CTX_load_verify_locations(SSL_context, ROOT_CERT_FILE, NULL))
789 /* Not fatal - we do not require client certificates */
791 (errmsg("could not load root certificate file \"%s\": %s",
792 ROOT_CERT_FILE, SSLerrmessage()),
793 errdetail("Will not verify client certificates.")));
798 * Check the Certificate Revocation List (CRL) if file exists.
799 * http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci803160,00.html
801 X509_STORE *cvstore = SSL_CTX_get_cert_store(SSL_context);
805 /* Set the flags to check against the complete CRL chain */
806 if (X509_STORE_load_locations(cvstore, ROOT_CRL_FILE, NULL) != 0)
807 /* OpenSSL 0.96 does not support X509_V_FLAG_CRL_CHECK */
808 #ifdef X509_V_FLAG_CRL_CHECK
809 X509_STORE_set_flags(cvstore,
810 X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL);
813 (errmsg("SSL Certificate Revocation List (CRL) file \"%s\" ignored",
815 errdetail("Installed SSL library does not support CRL.")));
819 /* Not fatal - we do not require CRL */
821 (errmsg("SSL Certificate Revocation List (CRL) file \"%s\" not found, skipping: %s",
822 ROOT_CRL_FILE, SSLerrmessage()),
823 errdetail("Will not check certificates against CRL.")));
827 SSL_CTX_set_verify(SSL_context,
829 SSL_VERIFY_FAIL_IF_NO_PEER_CERT |
830 SSL_VERIFY_CLIENT_ONCE),
836 * Destroy global SSL context.
843 SSL_CTX_free(SSL_context);
849 * Attempt to negotiate SSL connection.
852 open_server_SSL(Port *port)
860 if (!(port->ssl = SSL_new(SSL_context)))
863 (errcode(ERRCODE_PROTOCOL_VIOLATION),
864 errmsg("could not initialize SSL connection: %s",
869 if (!my_SSL_set_fd(port->ssl, port->sock))
872 (errcode(ERRCODE_PROTOCOL_VIOLATION),
873 errmsg("could not set SSL socket: %s",
880 r = SSL_accept(port->ssl);
883 err = SSL_get_error(port->ssl, r);
886 case SSL_ERROR_WANT_READ:
887 case SSL_ERROR_WANT_WRITE:
889 pgwin32_waitforsinglesocket(SSL_get_fd(port->ssl),
890 (err == SSL_ERROR_WANT_READ) ?
891 FD_READ | FD_CLOSE | FD_ACCEPT : FD_WRITE | FD_CLOSE);
894 case SSL_ERROR_SYSCALL:
897 (errcode_for_socket_access(),
898 errmsg("could not accept SSL connection: %m")));
901 (errcode(ERRCODE_PROTOCOL_VIOLATION),
902 errmsg("could not accept SSL connection: EOF detected")));
906 (errcode(ERRCODE_PROTOCOL_VIOLATION),
907 errmsg("could not accept SSL connection: %s",
910 case SSL_ERROR_ZERO_RETURN:
912 (errcode(ERRCODE_PROTOCOL_VIOLATION),
913 errmsg("could not accept SSL connection: EOF detected")));
917 (errcode(ERRCODE_PROTOCOL_VIOLATION),
918 errmsg("unrecognized SSL error code: %d",
928 /* get client certificate, if available. */
929 port->peer = SSL_get_peer_certificate(port->ssl);
930 if (port->peer == NULL)
932 strncpy(port->peer_dn, "(anonymous)", sizeof(port->peer_dn));
933 strncpy(port->peer_cn, "(anonymous)", sizeof(port->peer_cn));
937 X509_NAME_oneline(X509_get_subject_name(port->peer),
938 port->peer_dn, sizeof(port->peer_dn));
939 port->peer_dn[sizeof(port->peer_dn) - 1] = '\0';
940 X509_NAME_get_text_by_NID(X509_get_subject_name(port->peer),
941 NID_commonName, port->peer_cn, sizeof(port->peer_cn));
942 port->peer_cn[sizeof(port->peer_cn) - 1] = '\0';
945 (errmsg("SSL connection from \"%s\"", port->peer_cn)));
947 /* set up debugging/info callback */
948 SSL_CTX_set_info_callback(SSL_context, info_cb);
954 * Close SSL connection.
957 close_SSL(Port *port)
961 SSL_shutdown(port->ssl);
968 X509_free(port->peer);
974 * Obtain reason string for last SSL error
976 * Some caution is needed here since ERR_reason_error_string will
977 * return NULL if it doesn't recognize the error code. We don't
978 * want to return NULL ever.
983 unsigned long errcode;
984 const char *errreason;
985 static char errbuf[32];
987 errcode = ERR_get_error();
989 return "No SSL error reported";
990 errreason = ERR_reason_error_string(errcode);
991 if (errreason != NULL)
993 snprintf(errbuf, sizeof(errbuf), "SSL error code %lu", errcode);