1 /* Copyright (c) 2003, Roger Dingledine.
2 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
3 * Copyright (c) 2007-2011, The Tor Project, Inc. */
4 /* See LICENSE for licensing information */
8 * \brief Wrapper functions to present a consistent interface to
9 * TLS, SSL, and X.509 functions from OpenSSL.
12 /* (Unlike other tor functions, these
13 * are prefixed with tor_ in order to avoid conflicting with OpenSSL
14 * functions and variables.)
20 #ifdef MS_WINDOWS /*wrkard for dtls1.h >= 0.9.8m of "#include <winsock.h>"*/
21 #define WIN32_WINNT 0x400
22 #define _WIN32_WINNT 0x400
23 #define WIN32_LEAN_AND_MEAN
24 #if defined(_MSC_VER) && (_MSC_VER < 1300)
31 #include <openssl/ssl.h>
32 #include <openssl/ssl3.h>
33 #include <openssl/err.h>
34 #include <openssl/tls1.h>
35 #include <openssl/asn1.h>
36 #include <openssl/bio.h>
37 #include <openssl/opensslv.h>
39 #if OPENSSL_VERSION_NUMBER < 0x00907000l
40 #error "We require OpenSSL >= 0.9.7"
43 #define CRYPTO_PRIVATE /* to import prototypes from crypto.h */
49 #include "container.h"
53 /* Enable the "v2" TLS handshake.
55 #define V2_HANDSHAKE_SERVER
56 #define V2_HANDSHAKE_CLIENT
58 /* Copied from or.h */
59 #define LEGAL_NICKNAME_CHARACTERS \
60 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
62 /** How long do identity certificates live? (sec) */
63 #define IDENTITY_CERT_LIFETIME (365*24*60*60)
65 #define ADDR(tls) (((tls) && (tls)->address) ? tls->address : "peer")
67 /* We redefine these so that we can run correctly even if the vendor gives us
68 * a version of OpenSSL that does not match its header files. (Apple: I am
71 #ifndef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
72 #define SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0x00040000L
74 #ifndef SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
75 #define SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0x0010
78 /** Does the run-time openssl version look like we need
79 * SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION? */
80 static int use_unsafe_renegotiation_op
= 0;
81 /** Does the run-time openssl version look like we need
82 * SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION? */
83 static int use_unsafe_renegotiation_flag
= 0;
85 /** Structure holding the TLS state for a single connection. */
86 typedef struct tor_tls_context_t
{
94 /** Holds a SSL object and its associated data. Members are only
95 * accessed from within tortls.c.
98 HT_ENTRY(tor_tls_t
) node
;
99 tor_tls_context_t
*context
; /** A link to the context object for this tls. */
100 SSL
*ssl
; /**< An OpenSSL SSL object. */
101 int socket
; /**< The underlying file descriptor for this TLS connection. */
102 char *address
; /**< An address to log when describing this connection. */
104 TOR_TLS_ST_HANDSHAKE
, TOR_TLS_ST_OPEN
, TOR_TLS_ST_GOTCLOSE
,
105 TOR_TLS_ST_SENTCLOSE
, TOR_TLS_ST_CLOSED
, TOR_TLS_ST_RENEGOTIATE
,
106 } state
: 3; /**< The current SSL state, depending on which operations have
107 * completed successfully. */
108 unsigned int isServer
:1; /**< True iff this is a server-side connection */
109 unsigned int wasV2Handshake
:1; /**< True iff the original handshake for
110 * this connection used the updated version
111 * of the connection protocol (client sends
112 * different cipher list, server sends only
113 * one certificate). */
114 /** True iff we should call negotiated_callback when we're done reading. */
115 unsigned int got_renegotiate
:1;
116 size_t wantwrite_n
; /**< 0 normally, >0 if we returned wantwrite last
118 /** Last values retrieved from BIO_number_read()/write(); see
119 * tor_tls_get_n_raw_bytes() for usage.
121 unsigned long last_write_count
;
122 unsigned long last_read_count
;
123 /** If set, a callback to invoke whenever the client tries to renegotiate
125 void (*negotiated_callback
)(tor_tls_t
*tls
, void *arg
);
126 /** Argument to pass to negotiated_callback. */
130 #ifdef V2_HANDSHAKE_CLIENT
131 /** An array of fake SSL_CIPHER objects that we use in order to trick OpenSSL
132 * in client mode into advertising the ciphers we want. See
133 * rectify_client_ciphers() for details. */
134 static SSL_CIPHER
*CLIENT_CIPHER_DUMMIES
= NULL
;
135 /** A stack of SSL_CIPHER objects, some real, some fake.
136 * See rectify_client_ciphers() for details. */
137 static STACK_OF(SSL_CIPHER
) *CLIENT_CIPHER_STACK
= NULL
;
140 /** Helper: compare tor_tls_t objects by its SSL. */
142 tor_tls_entries_eq(const tor_tls_t
*a
, const tor_tls_t
*b
)
144 return a
->ssl
== b
->ssl
;
147 /** Helper: return a hash value for a tor_tls_t by its SSL. */
148 static INLINE
unsigned int
149 tor_tls_entry_hash(const tor_tls_t
*a
)
151 #if SIZEOF_INT == SIZEOF_VOID_P
152 return ((unsigned int)(uintptr_t)a
->ssl
);
154 return (unsigned int) ((((uint64_t)a
->ssl
)>>2) & UINT_MAX
);
158 /** Map from SSL* pointers to tor_tls_t objects using those pointers.
160 static HT_HEAD(tlsmap
, tor_tls_t
) tlsmap_root
= HT_INITIALIZER();
162 HT_PROTOTYPE(tlsmap
, tor_tls_t
, node
, tor_tls_entry_hash
,
164 HT_GENERATE(tlsmap
, tor_tls_t
, node
, tor_tls_entry_hash
,
165 tor_tls_entries_eq
, 0.6, malloc
, realloc
, free
)
167 /** Helper: given a SSL* pointer, return the tor_tls_t object using that
169 static INLINE tor_tls_t
*
170 tor_tls_get_by_ssl(const SSL
*ssl
)
172 tor_tls_t search
, *result
;
173 memset(&search
, 0, sizeof(search
));
174 search
.ssl
= (SSL
*)ssl
;
175 result
= HT_FIND(tlsmap
, &tlsmap_root
, &search
);
179 static void tor_tls_context_decref(tor_tls_context_t
*ctx
);
180 static void tor_tls_context_incref(tor_tls_context_t
*ctx
);
181 static X509
* tor_tls_create_certificate(crypto_pk_env_t
*rsa
,
182 crypto_pk_env_t
*rsa_sign
,
184 const char *cname_sign
,
185 unsigned int lifetime
);
186 static void tor_tls_unblock_renegotiation(tor_tls_t
*tls
);
187 static int tor_tls_context_init_one(tor_tls_context_t
**ppcontext
,
188 crypto_pk_env_t
*identity
,
189 unsigned int key_lifetime
);
190 static tor_tls_context_t
*tor_tls_context_new(crypto_pk_env_t
*identity
,
191 unsigned int key_lifetime
);
193 /** Global TLS contexts. We keep them here because nobody else needs
195 static tor_tls_context_t
*server_tls_context
= NULL
;
196 static tor_tls_context_t
*client_tls_context
= NULL
;
197 /** True iff tor_tls_init() has been called. */
198 static int tls_library_is_initialized
= 0;
200 /* Module-internal error codes. */
201 #define _TOR_TLS_SYSCALL (_MIN_TOR_TLS_ERROR_VAL - 2)
202 #define _TOR_TLS_ZERORETURN (_MIN_TOR_TLS_ERROR_VAL - 1)
204 /** Log all pending tls errors at level <b>severity</b>. Use
205 * <b>doing</b> to describe our current activities.
208 tls_log_errors(tor_tls_t
*tls
, int severity
, const char *doing
)
211 const char *msg
, *lib
, *func
, *addr
;
212 addr
= tls
? tls
->address
: NULL
;
213 while ((err
= ERR_get_error()) != 0) {
214 msg
= (const char*)ERR_reason_error_string(err
);
215 lib
= (const char*)ERR_lib_error_string(err
);
216 func
= (const char*)ERR_func_error_string(err
);
217 if (!msg
) msg
= "(null)";
218 if (!lib
) lib
= "(null)";
219 if (!func
) func
= "(null)";
221 log(severity
, LD_NET
, "TLS error while %s%s%s: %s (in %s:%s)",
222 doing
, addr
?" with ":"", addr
?addr
:"",
225 log(severity
, LD_NET
, "TLS error%s%s: %s (in %s:%s)",
226 addr
?" with ":"", addr
?addr
:"",
232 /** Convert an errno (or a WSAerrno on windows) into a TOR_TLS_* error
235 tor_errno_to_tls_error(int e
)
237 #if defined(MS_WINDOWS)
239 case WSAECONNRESET
: // most common
240 return TOR_TLS_ERROR_CONNRESET
;
242 return TOR_TLS_ERROR_TIMEOUT
;
244 case WSAEHOSTUNREACH
:
245 return TOR_TLS_ERROR_NO_ROUTE
;
246 case WSAECONNREFUSED
:
247 return TOR_TLS_ERROR_CONNREFUSED
; // least common
249 return TOR_TLS_ERROR_MISC
;
253 case ECONNRESET
: // most common
254 return TOR_TLS_ERROR_CONNRESET
;
256 return TOR_TLS_ERROR_TIMEOUT
;
259 return TOR_TLS_ERROR_NO_ROUTE
;
261 return TOR_TLS_ERROR_CONNREFUSED
; // least common
263 return TOR_TLS_ERROR_MISC
;
268 /** Given a TOR_TLS_* error code, return a string equivalent. */
270 tor_tls_err_to_string(int err
)
273 return "[Not an error.]";
275 case TOR_TLS_ERROR_MISC
: return "misc error";
276 case TOR_TLS_ERROR_IO
: return "unexpected close";
277 case TOR_TLS_ERROR_CONNREFUSED
: return "connection refused";
278 case TOR_TLS_ERROR_CONNRESET
: return "connection reset";
279 case TOR_TLS_ERROR_NO_ROUTE
: return "host unreachable";
280 case TOR_TLS_ERROR_TIMEOUT
: return "connection timed out";
281 case TOR_TLS_CLOSE
: return "closed";
282 case TOR_TLS_WANTREAD
: return "want to read";
283 case TOR_TLS_WANTWRITE
: return "want to write";
284 default: return "(unknown error code)";
288 #define CATCH_SYSCALL 1
291 /** Given a TLS object and the result of an SSL_* call, use
292 * SSL_get_error to determine whether an error has occurred, and if so
293 * which one. Return one of TOR_TLS_{DONE|WANTREAD|WANTWRITE|ERROR}.
294 * If extra&CATCH_SYSCALL is true, return _TOR_TLS_SYSCALL instead of
295 * reporting syscall errors. If extra&CATCH_ZERO is true, return
296 * _TOR_TLS_ZERORETURN instead of reporting zero-return errors.
298 * If an error has occurred, log it at level <b>severity</b> and describe the
299 * current action as <b>doing</b>.
302 tor_tls_get_error(tor_tls_t
*tls
, int r
, int extra
,
303 const char *doing
, int severity
)
305 int err
= SSL_get_error(tls
->ssl
, r
);
306 int tor_error
= TOR_TLS_ERROR_MISC
;
310 case SSL_ERROR_WANT_READ
:
311 return TOR_TLS_WANTREAD
;
312 case SSL_ERROR_WANT_WRITE
:
313 return TOR_TLS_WANTWRITE
;
314 case SSL_ERROR_SYSCALL
:
315 if (extra
&CATCH_SYSCALL
)
316 return _TOR_TLS_SYSCALL
;
318 log(severity
, LD_NET
, "TLS error: unexpected close while %s", doing
);
319 tor_error
= TOR_TLS_ERROR_IO
;
321 int e
= tor_socket_errno(tls
->socket
);
322 log(severity
, LD_NET
,
323 "TLS error: <syscall error while %s> (errno=%d: %s)",
324 doing
, e
, tor_socket_strerror(e
));
325 tor_error
= tor_errno_to_tls_error(e
);
327 tls_log_errors(tls
, severity
, doing
);
329 case SSL_ERROR_ZERO_RETURN
:
330 if (extra
&CATCH_ZERO
)
331 return _TOR_TLS_ZERORETURN
;
332 log(severity
, LD_NET
, "TLS connection closed while %s", doing
);
333 tls_log_errors(tls
, severity
, doing
);
334 return TOR_TLS_CLOSE
;
336 tls_log_errors(tls
, severity
, doing
);
337 return TOR_TLS_ERROR_MISC
;
341 /** Initialize OpenSSL, unless it has already been initialized.
346 if (!tls_library_is_initialized
) {
349 SSL_load_error_strings();
350 crypto_global_init(-1);
354 /* OpenSSL 0.9.8l introdeced SSL3_FLAGS_ALLOW_UNSAGE_LEGACY_RENEGOTIATION
355 * here, but without thinking too hard about it: it turns out that the
356 * flag in question needed to be set at the last minute, and that it
357 * conflicted with an existing flag number that had already been added
358 * in the OpenSSL 1.0.0 betas. OpenSSL 0.9.8m thoughtfully replaced
359 * the flag with an option and (it seems) broke anything that used
360 * SSL3_FLAGS_* for the purpose. So we need to know how to do both,
361 * and we mustn't use the SSL3_FLAGS option with anything besides
364 * No, we can't just set flag 0x0010 everywhere. It breaks Tor with
365 * OpenSSL 1.0.0beta3 and later. On the other hand, we might be able to
366 * set option 0x00040000L everywhere.
368 * No, we can't simply detect whether the flag or the option is present
369 * in the headers at build-time: some vendors (notably Apple) like to
370 * leave their headers out of sync with their libraries.
372 * Yes, it _is_ almost as if the OpenSSL developers decided that no
373 * program should be allowed to use renegotiation its first passed an
374 * test of intelligence and determination.
376 if (version
>= 0x009080c0L
&& version
< 0x009080d0L
) {
377 log_notice(LD_GENERAL
, "OpenSSL %s looks like version 0.9.8l; "
378 "I will try SSL3_FLAGS to enable renegotation.",
379 SSLeay_version(SSLEAY_VERSION
));
380 use_unsafe_renegotiation_flag
= 1;
381 use_unsafe_renegotiation_op
= 1;
382 } else if (version
>= 0x009080d0L
) {
383 log_notice(LD_GENERAL
, "OpenSSL %s looks like version 0.9.8m or later; "
384 "I will try SSL_OP to enable renegotiation",
385 SSLeay_version(SSLEAY_VERSION
));
386 use_unsafe_renegotiation_op
= 1;
387 } else if (version
< 0x009080c0L
) {
388 log_notice(LD_GENERAL
, "OpenSSL %s [%lx] looks like it's older than "
389 "0.9.8l, but some vendors have backported 0.9.8l's "
390 "renegotiation code to earlier versions, and some have "
391 "backported the code from 0.9.8m or 0.9.8n. I'll set both "
392 "SSL3_FLAGS and SSL_OP just to be safe.",
393 SSLeay_version(SSLEAY_VERSION
), version
);
394 use_unsafe_renegotiation_flag
= 1;
395 use_unsafe_renegotiation_op
= 1;
397 log_info(LD_GENERAL
, "OpenSSL %s has version %lx",
398 SSLeay_version(SSLEAY_VERSION
), version
);
401 tls_library_is_initialized
= 1;
405 /** Free all global TLS structures. */
407 tor_tls_free_all(void)
409 if (server_tls_context
) {
410 tor_tls_context_t
*ctx
= server_tls_context
;
411 server_tls_context
= NULL
;
412 tor_tls_context_decref(ctx
);
414 if (client_tls_context
) {
415 tor_tls_context_t
*ctx
= client_tls_context
;
416 client_tls_context
= NULL
;
417 tor_tls_context_decref(ctx
);
419 if (!HT_EMPTY(&tlsmap_root
)) {
420 log_warn(LD_MM
, "Still have entries in the tlsmap at shutdown.");
422 HT_CLEAR(tlsmap
, &tlsmap_root
);
423 #ifdef V2_HANDSHAKE_CLIENT
424 if (CLIENT_CIPHER_DUMMIES
)
425 tor_free(CLIENT_CIPHER_DUMMIES
);
426 if (CLIENT_CIPHER_STACK
)
427 sk_SSL_CIPHER_free(CLIENT_CIPHER_STACK
);
431 /** We need to give OpenSSL a callback to verify certificates. This is
432 * it: We always accept peer certs and complete the handshake. We
433 * don't validate them until later.
436 always_accept_verify_cb(int preverify_ok
,
437 X509_STORE_CTX
*x509_ctx
)
444 /** Return a newly allocated X509 name with commonName <b>cname</b>. */
446 tor_x509_name_new(const char *cname
)
450 if (!(name
= X509_NAME_new()))
452 if ((nid
= OBJ_txt2nid("commonName")) == NID_undef
) goto error
;
453 if (!(X509_NAME_add_entry_by_NID(name
, nid
, MBSTRING_ASC
,
454 (unsigned char*)cname
, -1, -1, 0)))
458 X509_NAME_free(name
);
462 /** Generate and sign an X509 certificate with the public key <b>rsa</b>,
463 * signed by the private key <b>rsa_sign</b>. The commonName of the
464 * certificate will be <b>cname</b>; the commonName of the issuer will be
465 * <b>cname_sign</b>. The cert will be valid for <b>cert_lifetime</b> seconds
466 * starting from now. Return a certificate on success, NULL on
470 tor_tls_create_certificate(crypto_pk_env_t
*rsa
,
471 crypto_pk_env_t
*rsa_sign
,
473 const char *cname_sign
,
474 unsigned int cert_lifetime
)
476 time_t start_time
, end_time
;
477 EVP_PKEY
*sign_pkey
= NULL
, *pkey
=NULL
;
479 X509_NAME
*name
= NULL
, *name_issuer
=NULL
;
483 start_time
= time(NULL
);
487 tor_assert(rsa_sign
);
488 tor_assert(cname_sign
);
489 if (!(sign_pkey
= _crypto_pk_env_get_evp_pkey(rsa_sign
,1)))
491 if (!(pkey
= _crypto_pk_env_get_evp_pkey(rsa
,0)))
493 if (!(x509
= X509_new()))
495 if (!(X509_set_version(x509
, 2)))
497 if (!(ASN1_INTEGER_set(X509_get_serialNumber(x509
), (long)start_time
)))
500 if (!(name
= tor_x509_name_new(cname
)))
502 if (!(X509_set_subject_name(x509
, name
)))
504 if (!(name_issuer
= tor_x509_name_new(cname_sign
)))
506 if (!(X509_set_issuer_name(x509
, name_issuer
)))
509 if (!X509_time_adj(X509_get_notBefore(x509
),0,&start_time
))
511 end_time
= start_time
+ cert_lifetime
;
512 if (!X509_time_adj(X509_get_notAfter(x509
),0,&end_time
))
514 if (!X509_set_pubkey(x509
, pkey
))
516 if (!X509_sign(x509
, sign_pkey
, EVP_sha1()))
526 tls_log_errors(NULL
, LOG_WARN
, "generating certificate");
528 EVP_PKEY_free(sign_pkey
);
532 X509_NAME_free(name
);
534 X509_NAME_free(name_issuer
);
538 /** List of ciphers that servers should select from.*/
539 #define SERVER_CIPHER_LIST \
540 (TLS1_TXT_DHE_RSA_WITH_AES_256_SHA ":" \
541 TLS1_TXT_DHE_RSA_WITH_AES_128_SHA ":" \
542 SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA)
543 /* Note: for setting up your own private testing network with link crypto
544 * disabled, set the cipher lists to your cipher list to
545 * SSL3_TXT_RSA_NULL_SHA. If you do this, you won't be able to communicate
546 * with any of the "real" Tors, though. */
548 #ifdef V2_HANDSHAKE_CLIENT
549 #define CIPHER(id, name) name ":"
550 #define XCIPHER(id, name)
551 /** List of ciphers that clients should advertise, omitting items that
552 * our OpenSSL doesn't know about. */
553 static const char CLIENT_CIPHER_LIST
[] =
554 #include "./ciphers.inc"
559 /** Holds a cipher that we want to advertise, and its 2-byte ID. */
560 typedef struct cipher_info_t
{ unsigned id
; const char *name
; } cipher_info_t
;
561 /** A list of all the ciphers that clients should advertise, including items
562 * that OpenSSL might not know about. */
563 static const cipher_info_t CLIENT_CIPHER_INFO_LIST
[] = {
564 #define CIPHER(id, name) { id, name },
565 #define XCIPHER(id, name) { id, #name },
566 #include "./ciphers.inc"
571 /** The length of CLIENT_CIPHER_INFO_LIST and CLIENT_CIPHER_DUMMIES. */
572 static const int N_CLIENT_CIPHERS
=
573 sizeof(CLIENT_CIPHER_INFO_LIST
)/sizeof(CLIENT_CIPHER_INFO_LIST
[0]);
576 #ifndef V2_HANDSHAKE_CLIENT
577 #undef CLIENT_CIPHER_LIST
578 #define CLIENT_CIPHER_LIST (TLS1_TXT_DHE_RSA_WITH_AES_128_SHA ":" \
579 SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA)
582 /** Remove a reference to <b>ctx</b>, and free it if it has no more
585 tor_tls_context_decref(tor_tls_context_t
*ctx
)
588 if (--ctx
->refcnt
== 0) {
589 SSL_CTX_free(ctx
->ctx
);
590 X509_free(ctx
->my_cert
);
591 X509_free(ctx
->my_id_cert
);
592 crypto_free_pk_env(ctx
->key
);
597 /** Increase the reference count of <b>ctx</b>. */
599 tor_tls_context_incref(tor_tls_context_t
*ctx
)
604 /** Create new global client and server TLS contexts.
606 * If <b>server_identity</b> is NULL, this will not generate a server
607 * TLS context. If <b>is_public_server</b> is non-zero, this will use
608 * the same TLS context for incoming and outgoing connections, and
609 * ignore <b>client_identity</b>. */
611 tor_tls_context_init(int is_public_server
,
612 crypto_pk_env_t
*client_identity
,
613 crypto_pk_env_t
*server_identity
,
614 unsigned int key_lifetime
)
619 if (is_public_server
) {
620 tor_tls_context_t
*new_ctx
;
621 tor_tls_context_t
*old_ctx
;
623 tor_assert(server_identity
!= NULL
);
625 rv1
= tor_tls_context_init_one(&server_tls_context
,
630 new_ctx
= server_tls_context
;
631 tor_tls_context_incref(new_ctx
);
632 old_ctx
= client_tls_context
;
633 client_tls_context
= new_ctx
;
635 if (old_ctx
!= NULL
) {
636 tor_tls_context_decref(old_ctx
);
640 if (server_identity
!= NULL
) {
641 rv1
= tor_tls_context_init_one(&server_tls_context
,
645 tor_tls_context_t
*old_ctx
= server_tls_context
;
646 server_tls_context
= NULL
;
648 if (old_ctx
!= NULL
) {
649 tor_tls_context_decref(old_ctx
);
653 rv2
= tor_tls_context_init_one(&client_tls_context
,
658 return rv1
< rv2
? rv1
: rv2
;
661 /** Create a new TLS context for use with Tor TLS handshakes.
662 * <b>identity</b> should be set to the identity key used to sign the
665 * You can call this function multiple times. Each time you call it,
666 * it generates new certificates; all new connections will use
667 * the new SSL context.
670 tor_tls_context_init_one(tor_tls_context_t
**ppcontext
,
671 crypto_pk_env_t
*identity
,
672 unsigned int key_lifetime
)
674 tor_tls_context_t
*new_ctx
= tor_tls_context_new(identity
,
676 tor_tls_context_t
*old_ctx
= *ppcontext
;
678 if (new_ctx
!= NULL
) {
679 *ppcontext
= new_ctx
;
681 /* Free the old context if one existed. */
682 if (old_ctx
!= NULL
) {
683 /* This is safe even if there are open connections: we reference-
684 * count tor_tls_context_t objects. */
685 tor_tls_context_decref(old_ctx
);
689 return ((new_ctx
!= NULL
) ? 0 : -1);
692 /** Create a new TLS context for use with Tor TLS handshakes.
693 * <b>identity</b> should be set to the identity key used to sign the
696 static tor_tls_context_t
*
697 tor_tls_context_new(crypto_pk_env_t
*identity
, unsigned int key_lifetime
)
699 crypto_pk_env_t
*rsa
= NULL
;
700 EVP_PKEY
*pkey
= NULL
;
701 tor_tls_context_t
*result
= NULL
;
702 X509
*cert
= NULL
, *idcert
= NULL
;
703 char *nickname
= NULL
, *nn2
= NULL
;
706 nickname
= crypto_random_hostname(8, 20, "www.", ".net");
707 nn2
= crypto_random_hostname(8, 20, "www.", ".net");
709 /* Generate short-term RSA key. */
710 if (!(rsa
= crypto_new_pk_env()))
712 if (crypto_pk_generate_key(rsa
)<0)
714 /* Create certificate signed by identity key. */
715 cert
= tor_tls_create_certificate(rsa
, identity
, nickname
, nn2
,
717 /* Create self-signed certificate for identity key. */
718 idcert
= tor_tls_create_certificate(identity
, identity
, nn2
, nn2
,
719 IDENTITY_CERT_LIFETIME
);
720 if (!cert
|| !idcert
) {
721 log(LOG_WARN
, LD_CRYPTO
, "Error creating certificate");
725 result
= tor_malloc_zero(sizeof(tor_tls_context_t
));
727 result
->my_cert
= X509_dup(cert
);
728 result
->my_id_cert
= X509_dup(idcert
);
729 result
->key
= crypto_pk_dup_key(rsa
);
731 #ifdef EVERYONE_HAS_AES
732 /* Tell OpenSSL to only use TLS1 */
733 if (!(result
->ctx
= SSL_CTX_new(TLSv1_method())))
736 /* Tell OpenSSL to use SSL3 or TLS1 but not SSL2. */
737 if (!(result
->ctx
= SSL_CTX_new(SSLv23_method())))
739 SSL_CTX_set_options(result
->ctx
, SSL_OP_NO_SSLv2
);
741 SSL_CTX_set_options(result
->ctx
, SSL_OP_SINGLE_DH_USE
);
743 #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
744 SSL_CTX_set_options(result
->ctx
,
745 SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
);
747 /* Yes, we know what we are doing here. No, we do not treat a renegotiation
748 * as authenticating any earlier-received data.
750 if (use_unsafe_renegotiation_op
) {
751 SSL_CTX_set_options(result
->ctx
,
752 SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
);
754 /* Don't actually allow compression; it uses ram and time, but the data
755 * we transmit is all encrypted anyway. */
756 if (result
->ctx
->comp_methods
)
757 result
->ctx
->comp_methods
= NULL
;
758 #ifdef SSL_MODE_RELEASE_BUFFERS
759 SSL_CTX_set_mode(result
->ctx
, SSL_MODE_RELEASE_BUFFERS
);
761 if (cert
&& !SSL_CTX_use_certificate(result
->ctx
,cert
))
763 X509_free(cert
); /* We just added a reference to cert. */
766 X509_STORE
*s
= SSL_CTX_get_cert_store(result
->ctx
);
768 X509_STORE_add_cert(s
, idcert
);
769 X509_free(idcert
); /* The context now owns the reference to idcert */
772 SSL_CTX_set_session_cache_mode(result
->ctx
, SSL_SESS_CACHE_OFF
);
774 if (!(pkey
= _crypto_pk_env_get_evp_pkey(rsa
,1)))
776 if (!SSL_CTX_use_PrivateKey(result
->ctx
, pkey
))
780 if (!SSL_CTX_check_private_key(result
->ctx
))
783 crypto_dh_env_t
*dh
= crypto_dh_new(DH_TYPE_TLS
);
784 SSL_CTX_set_tmp_dh(result
->ctx
, _crypto_dh_env_get_dh(dh
));
787 SSL_CTX_set_verify(result
->ctx
, SSL_VERIFY_PEER
,
788 always_accept_verify_cb
);
789 /* let us realloc bufs that we're writing from */
790 SSL_CTX_set_mode(result
->ctx
, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER
);
793 crypto_free_pk_env(rsa
);
799 tls_log_errors(NULL
, LOG_WARN
, "creating TLS context");
805 crypto_free_pk_env(rsa
);
807 tor_tls_context_decref(result
);
815 #ifdef V2_HANDSHAKE_SERVER
816 /** Return true iff the cipher list suggested by the client for <b>ssl</b> is
817 * a list that indicates that the client knows how to do the v2 TLS connection
820 tor_tls_client_is_using_v2_ciphers(const SSL
*ssl
, const char *address
)
823 SSL_SESSION
*session
;
824 /* If we reached this point, we just got a client hello. See if there is
826 if (!(session
= SSL_get_session((SSL
*)ssl
))) {
827 log_warn(LD_NET
, "No session on TLS?");
830 if (!session
->ciphers
) {
831 log_warn(LD_NET
, "No ciphers on session");
834 /* Now we need to see if there are any ciphers whose presence means we're
835 * dealing with an updated Tor. */
836 for (i
= 0; i
< sk_SSL_CIPHER_num(session
->ciphers
); ++i
) {
837 SSL_CIPHER
*cipher
= sk_SSL_CIPHER_value(session
->ciphers
, i
);
838 const char *ciphername
= SSL_CIPHER_get_name(cipher
);
839 if (strcmp(ciphername
, TLS1_TXT_DHE_RSA_WITH_AES_128_SHA
) &&
840 strcmp(ciphername
, TLS1_TXT_DHE_RSA_WITH_AES_256_SHA
) &&
841 strcmp(ciphername
, SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA
) &&
842 strcmp(ciphername
, "(NONE)")) {
843 /* XXXX should be ld_debug */
844 log_info(LD_NET
, "Got a non-version-1 cipher called '%s'", ciphername
);
852 smartlist_t
*elts
= smartlist_create();
854 for (i
= 0; i
< sk_SSL_CIPHER_num(session
->ciphers
); ++i
) {
855 SSL_CIPHER
*cipher
= sk_SSL_CIPHER_value(session
->ciphers
, i
);
856 const char *ciphername
= SSL_CIPHER_get_name(cipher
);
857 smartlist_add(elts
, (char*)ciphername
);
859 s
= smartlist_join_strings(elts
, ":", 0, NULL
);
860 log_info(LD_NET
, "Got a non-version-1 cipher list from %s. It is: '%s'",
863 smartlist_free(elts
);
868 /** Invoked when we're accepting a connection on <b>ssl</b>, and the connection
869 * changes state. We use this:
870 * <ul><li>To alter the state of the handshake partway through, so we
871 * do not send or request extra certificates in v2 handshakes.</li>
872 * <li>To detect renegotiation</li></ul>
875 tor_tls_server_info_callback(const SSL
*ssl
, int type
, int val
)
879 if (type
!= SSL_CB_ACCEPT_LOOP
)
881 if (ssl
->state
!= SSL3_ST_SW_SRVR_HELLO_A
)
884 tls
= tor_tls_get_by_ssl(ssl
);
886 /* Check whether we're watching for renegotiates. If so, this is one! */
887 if (tls
->negotiated_callback
)
888 tls
->got_renegotiate
= 1;
890 log_warn(LD_BUG
, "Couldn't look up the tls for an SSL*. How odd!");
893 /* Now check the cipher list. */
894 if (tor_tls_client_is_using_v2_ciphers(ssl
, ADDR(tls
))) {
895 /*XXXX_TLS keep this from happening more than once! */
897 /* Yes, we're casting away the const from ssl. This is very naughty of us.
898 * Let's hope openssl doesn't notice! */
900 /* Set SSL_MODE_NO_AUTO_CHAIN to keep from sending back any extra certs. */
901 SSL_set_mode((SSL
*) ssl
, SSL_MODE_NO_AUTO_CHAIN
);
902 /* Don't send a hello request. */
903 SSL_set_verify((SSL
*) ssl
, SSL_VERIFY_NONE
, NULL
);
906 tls
->wasV2Handshake
= 1;
908 log_warn(LD_BUG
, "Couldn't look up the tls for an SSL*. How odd!");
914 /** Replace *<b>ciphers</b> with a new list of SSL ciphersuites: specifically,
915 * a list designed to mimic a common web browser. Some of the ciphers in the
916 * list won't actually be implemented by OpenSSL: that's okay so long as the
917 * server doesn't select them, and the server won't select anything besides
918 * what's in SERVER_CIPHER_LIST.
920 * [If the server <b>does</b> select a bogus cipher, we won't crash or
921 * anything; we'll just fail later when we try to look up the cipher in
922 * ssl->cipher_list_by_id.]
925 rectify_client_ciphers(STACK_OF(SSL_CIPHER
) **ciphers
)
927 #ifdef V2_HANDSHAKE_CLIENT
928 if (PREDICT_UNLIKELY(!CLIENT_CIPHER_STACK
)) {
929 /* We need to set CLIENT_CIPHER_STACK to an array of the ciphers
933 /* First, create a dummy SSL_CIPHER for every cipher. */
934 CLIENT_CIPHER_DUMMIES
=
935 tor_malloc_zero(sizeof(SSL_CIPHER
)*N_CLIENT_CIPHERS
);
936 for (i
=0; i
< N_CLIENT_CIPHERS
; ++i
) {
937 CLIENT_CIPHER_DUMMIES
[i
].valid
= 1;
938 CLIENT_CIPHER_DUMMIES
[i
].id
= CLIENT_CIPHER_INFO_LIST
[i
].id
| (3<<24);
939 CLIENT_CIPHER_DUMMIES
[i
].name
= CLIENT_CIPHER_INFO_LIST
[i
].name
;
942 CLIENT_CIPHER_STACK
= sk_SSL_CIPHER_new_null();
943 tor_assert(CLIENT_CIPHER_STACK
);
945 log_debug(LD_NET
, "List was: %s", CLIENT_CIPHER_LIST
);
946 for (j
= 0; j
< sk_SSL_CIPHER_num(*ciphers
); ++j
) {
947 SSL_CIPHER
*cipher
= sk_SSL_CIPHER_value(*ciphers
, j
);
948 log_debug(LD_NET
, "Cipher %d: %lx %s", j
, cipher
->id
, cipher
->name
);
951 /* Then copy as many ciphers as we can from the good list, inserting
952 * dummies as needed. */
954 for (i
= 0; i
< N_CLIENT_CIPHERS
; ) {
955 SSL_CIPHER
*cipher
= NULL
;
956 if (j
< sk_SSL_CIPHER_num(*ciphers
))
957 cipher
= sk_SSL_CIPHER_value(*ciphers
, j
);
958 if (cipher
&& ((cipher
->id
>> 24) & 0xff) != 3) {
959 log_debug(LD_NET
, "Skipping v2 cipher %s", cipher
->name
);
962 (cipher
->id
& 0xffff) == CLIENT_CIPHER_INFO_LIST
[i
].id
) {
963 log_debug(LD_NET
, "Found cipher %s", cipher
->name
);
964 sk_SSL_CIPHER_push(CLIENT_CIPHER_STACK
, cipher
);
968 log_debug(LD_NET
, "Inserting fake %s", CLIENT_CIPHER_DUMMIES
[i
].name
);
969 sk_SSL_CIPHER_push(CLIENT_CIPHER_STACK
, &CLIENT_CIPHER_DUMMIES
[i
]);
975 sk_SSL_CIPHER_free(*ciphers
);
976 *ciphers
= sk_SSL_CIPHER_dup(CLIENT_CIPHER_STACK
);
977 tor_assert(*ciphers
);
984 /** Create a new TLS object from a file descriptor, and a flag to
985 * determine whether it is functioning as a server.
988 tor_tls_new(int sock
, int isServer
)
991 tor_tls_t
*result
= tor_malloc_zero(sizeof(tor_tls_t
));
992 tor_tls_context_t
*context
= isServer
? server_tls_context
:
995 tor_assert(context
); /* make sure somebody made it first */
996 if (!(result
->ssl
= SSL_new(context
->ctx
))) {
997 tls_log_errors(NULL
, LOG_WARN
, "creating SSL object");
1002 #ifdef SSL_set_tlsext_host_name
1003 /* Browsers use the TLS hostname extension, so we should too. */
1005 char *fake_hostname
= crypto_random_hostname(4,25, "www.",".com");
1006 SSL_set_tlsext_host_name(result
->ssl
, fake_hostname
);
1007 tor_free(fake_hostname
);
1011 if (!SSL_set_cipher_list(result
->ssl
,
1012 isServer
? SERVER_CIPHER_LIST
: CLIENT_CIPHER_LIST
)) {
1013 tls_log_errors(NULL
, LOG_WARN
, "setting ciphers");
1014 #ifdef SSL_set_tlsext_host_name
1015 SSL_set_tlsext_host_name(result
->ssl
, NULL
);
1017 SSL_free(result
->ssl
);
1022 rectify_client_ciphers(&result
->ssl
->cipher_list
);
1023 result
->socket
= sock
;
1024 bio
= BIO_new_socket(sock
, BIO_NOCLOSE
);
1026 tls_log_errors(NULL
, LOG_WARN
, "opening BIO");
1027 #ifdef SSL_set_tlsext_host_name
1028 SSL_set_tlsext_host_name(result
->ssl
, NULL
);
1030 SSL_free(result
->ssl
);
1034 HT_INSERT(tlsmap
, &tlsmap_root
, result
);
1035 SSL_set_bio(result
->ssl
, bio
, bio
);
1036 tor_tls_context_incref(context
);
1037 result
->context
= context
;
1038 result
->state
= TOR_TLS_ST_HANDSHAKE
;
1039 result
->isServer
= isServer
;
1040 result
->wantwrite_n
= 0;
1041 result
->last_write_count
= BIO_number_written(bio
);
1042 result
->last_read_count
= BIO_number_read(bio
);
1043 if (result
->last_write_count
|| result
->last_read_count
) {
1044 log_warn(LD_NET
, "Newly created BIO has read count %lu, write count %lu",
1045 result
->last_read_count
, result
->last_write_count
);
1047 #ifdef V2_HANDSHAKE_SERVER
1049 SSL_set_info_callback(result
->ssl
, tor_tls_server_info_callback
);
1053 /* Not expected to get called. */
1054 tls_log_errors(NULL
, LOG_WARN
, "generating TLS context");
1058 /** Make future log messages about <b>tls</b> display the address
1062 tor_tls_set_logged_address(tor_tls_t
*tls
, const char *address
)
1065 tor_free(tls
->address
);
1066 tls
->address
= tor_strdup(address
);
1069 /** Set <b>cb</b> to be called with argument <b>arg</b> whenever <b>tls</b>
1070 * next gets a client-side renegotiate in the middle of a read. Do not
1071 * invoke this function until <em>after</em> initial handshaking is done!
1074 tor_tls_set_renegotiate_callback(tor_tls_t
*tls
,
1075 void (*cb
)(tor_tls_t
*, void *arg
),
1078 tls
->negotiated_callback
= cb
;
1079 tls
->callback_arg
= arg
;
1080 tls
->got_renegotiate
= 0;
1081 #ifdef V2_HANDSHAKE_SERVER
1083 SSL_set_info_callback(tls
->ssl
, tor_tls_server_info_callback
);
1085 SSL_set_info_callback(tls
->ssl
, NULL
);
1090 /** If this version of openssl requires it, turn on renegotiation on
1094 tor_tls_unblock_renegotiation(tor_tls_t
*tls
)
1096 /* Yes, we know what we are doing here. No, we do not treat a renegotiation
1097 * as authenticating any earlier-received data. */
1098 if (use_unsafe_renegotiation_flag
) {
1099 tls
->ssl
->s3
->flags
|= SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
;
1101 if (use_unsafe_renegotiation_op
) {
1102 SSL_set_options(tls
->ssl
,
1103 SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
);
1107 /** If this version of openssl supports it, turn off renegotiation on
1108 * <b>tls</b>. (Our protocol never requires this for security, but it's nice
1109 * to use belt-and-suspenders here.)
1112 tor_tls_block_renegotiation(tor_tls_t
*tls
)
1114 tls
->ssl
->s3
->flags
&= ~SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
;
1117 /** Return whether this tls initiated the connect (client) or
1118 * received it (server). */
1120 tor_tls_is_server(tor_tls_t
*tls
)
1123 return tls
->isServer
;
1126 /** Release resources associated with a TLS object. Does not close the
1127 * underlying file descriptor.
1130 tor_tls_free(tor_tls_t
*tls
)
1133 tor_assert(tls
&& tls
->ssl
);
1134 removed
= HT_REMOVE(tlsmap
, &tlsmap_root
, tls
);
1136 log_warn(LD_BUG
, "Freeing a TLS that was not in the ssl->tls map.");
1138 #ifdef SSL_set_tlsext_host_name
1139 SSL_set_tlsext_host_name(tls
->ssl
, NULL
);
1143 tls
->negotiated_callback
= NULL
;
1145 tor_tls_context_decref(tls
->context
);
1146 tor_free(tls
->address
);
1150 /** Underlying function for TLS reading. Reads up to <b>len</b>
1151 * characters from <b>tls</b> into <b>cp</b>. On success, returns the
1152 * number of characters read. On failure, returns TOR_TLS_ERROR,
1153 * TOR_TLS_CLOSE, TOR_TLS_WANTREAD, or TOR_TLS_WANTWRITE.
1156 tor_tls_read(tor_tls_t
*tls
, char *cp
, size_t len
)
1160 tor_assert(tls
->ssl
);
1161 tor_assert(tls
->state
== TOR_TLS_ST_OPEN
);
1162 tor_assert(len
<INT_MAX
);
1163 r
= SSL_read(tls
->ssl
, cp
, (int)len
);
1165 #ifdef V2_HANDSHAKE_SERVER
1166 if (tls
->got_renegotiate
) {
1167 /* Renegotiation happened! */
1168 log_info(LD_NET
, "Got a TLS renegotiation from %s", ADDR(tls
));
1169 if (tls
->negotiated_callback
)
1170 tls
->negotiated_callback(tls
, tls
->callback_arg
);
1171 tls
->got_renegotiate
= 0;
1176 err
= tor_tls_get_error(tls
, r
, CATCH_ZERO
, "reading", LOG_DEBUG
);
1177 if (err
== _TOR_TLS_ZERORETURN
|| err
== TOR_TLS_CLOSE
) {
1178 log_debug(LD_NET
,"read returned r=%d; TLS is closed",r
);
1179 tls
->state
= TOR_TLS_ST_CLOSED
;
1180 return TOR_TLS_CLOSE
;
1182 tor_assert(err
!= TOR_TLS_DONE
);
1183 log_debug(LD_NET
,"read returned r=%d, err=%d",r
,err
);
1188 /** Underlying function for TLS writing. Write up to <b>n</b>
1189 * characters from <b>cp</b> onto <b>tls</b>. On success, returns the
1190 * number of characters written. On failure, returns TOR_TLS_ERROR,
1191 * TOR_TLS_WANTREAD, or TOR_TLS_WANTWRITE.
1194 tor_tls_write(tor_tls_t
*tls
, const char *cp
, size_t n
)
1198 tor_assert(tls
->ssl
);
1199 tor_assert(tls
->state
== TOR_TLS_ST_OPEN
);
1200 tor_assert(n
< INT_MAX
);
1203 if (tls
->wantwrite_n
) {
1204 /* if WANTWRITE last time, we must use the _same_ n as before */
1205 tor_assert(n
>= tls
->wantwrite_n
);
1206 log_debug(LD_NET
,"resuming pending-write, (%d to flush, reusing %d)",
1207 (int)n
, (int)tls
->wantwrite_n
);
1208 n
= tls
->wantwrite_n
;
1209 tls
->wantwrite_n
= 0;
1211 r
= SSL_write(tls
->ssl
, cp
, (int)n
);
1212 err
= tor_tls_get_error(tls
, r
, 0, "writing", LOG_INFO
);
1213 if (err
== TOR_TLS_DONE
) {
1216 if (err
== TOR_TLS_WANTWRITE
|| err
== TOR_TLS_WANTREAD
) {
1217 tls
->wantwrite_n
= n
;
1222 /** Perform initial handshake on <b>tls</b>. When finished, returns
1223 * TOR_TLS_DONE. On failure, returns TOR_TLS_ERROR, TOR_TLS_WANTREAD,
1224 * or TOR_TLS_WANTWRITE.
1227 tor_tls_handshake(tor_tls_t
*tls
)
1231 tor_assert(tls
->ssl
);
1232 tor_assert(tls
->state
== TOR_TLS_ST_HANDSHAKE
);
1233 check_no_tls_errors();
1234 if (tls
->isServer
) {
1235 r
= SSL_accept(tls
->ssl
);
1237 r
= SSL_connect(tls
->ssl
);
1239 /* We need to call this here and not earlier, since OpenSSL has a penchant
1240 * for clearing its flags when you say accept or connect. */
1241 tor_tls_unblock_renegotiation(tls
);
1242 r
= tor_tls_get_error(tls
,r
,0, "handshaking", LOG_INFO
);
1243 if (ERR_peek_error() != 0) {
1244 tls_log_errors(tls
, tls
->isServer
? LOG_INFO
: LOG_WARN
,
1246 return TOR_TLS_ERROR_MISC
;
1248 if (r
== TOR_TLS_DONE
) {
1249 tls
->state
= TOR_TLS_ST_OPEN
;
1250 if (tls
->isServer
) {
1251 SSL_set_info_callback(tls
->ssl
, NULL
);
1252 SSL_set_verify(tls
->ssl
, SSL_VERIFY_PEER
, always_accept_verify_cb
);
1253 /* There doesn't seem to be a clear OpenSSL API to clear mode flags. */
1254 tls
->ssl
->mode
&= ~SSL_MODE_NO_AUTO_CHAIN
;
1255 #ifdef V2_HANDSHAKE_SERVER
1256 if (tor_tls_client_is_using_v2_ciphers(tls
->ssl
, ADDR(tls
))) {
1257 /* This check is redundant, but back when we did it in the callback,
1258 * we might have not been able to look up the tor_tls_t if the code
1259 * was buggy. Fixing that. */
1260 if (!tls
->wasV2Handshake
) {
1261 log_warn(LD_BUG
, "For some reason, wasV2Handshake didn't"
1262 " get set. Fixing that.");
1264 tls
->wasV2Handshake
= 1;
1265 log_debug(LD_NET
, "Completed V2 TLS handshake with client; waiting "
1266 "for renegotiation.");
1268 tls
->wasV2Handshake
= 0;
1272 #ifdef V2_HANDSHAKE_CLIENT
1273 /* If we got no ID cert, we're a v2 handshake. */
1274 X509
*cert
= SSL_get_peer_certificate(tls
->ssl
);
1275 STACK_OF(X509
) *chain
= SSL_get_peer_cert_chain(tls
->ssl
);
1276 int n_certs
= sk_X509_num(chain
);
1277 if (n_certs
> 1 || (n_certs
== 1 && cert
!= sk_X509_value(chain
, 0)))
1278 tls
->wasV2Handshake
= 0;
1280 log_debug(LD_NET
, "Server sent back a single certificate; looks like "
1281 "a v2 handshake on %p.", tls
);
1282 tls
->wasV2Handshake
= 1;
1287 if (SSL_set_cipher_list(tls
->ssl
, SERVER_CIPHER_LIST
) == 0) {
1288 tls_log_errors(NULL
, LOG_WARN
, "re-setting ciphers");
1289 r
= TOR_TLS_ERROR_MISC
;
1296 /** Client only: Renegotiate a TLS session. When finished, returns
1297 * TOR_TLS_DONE. On failure, returns TOR_TLS_ERROR, TOR_TLS_WANTREAD, or
1298 * TOR_TLS_WANTWRITE.
1301 tor_tls_renegotiate(tor_tls_t
*tls
)
1305 /* We could do server-initiated renegotiation too, but that would be tricky.
1306 * Instead of "SSL_renegotiate, then SSL_do_handshake until done" */
1307 tor_assert(!tls
->isServer
);
1308 if (tls
->state
!= TOR_TLS_ST_RENEGOTIATE
) {
1309 int r
= SSL_renegotiate(tls
->ssl
);
1311 return tor_tls_get_error(tls
, r
, 0, "renegotiating", LOG_WARN
);
1313 tls
->state
= TOR_TLS_ST_RENEGOTIATE
;
1315 r
= SSL_do_handshake(tls
->ssl
);
1317 tls
->state
= TOR_TLS_ST_OPEN
;
1318 return TOR_TLS_DONE
;
1320 return tor_tls_get_error(tls
, r
, 0, "renegotiating handshake", LOG_INFO
);
1323 /** Shut down an open tls connection <b>tls</b>. When finished, returns
1324 * TOR_TLS_DONE. On failure, returns TOR_TLS_ERROR, TOR_TLS_WANTREAD,
1325 * or TOR_TLS_WANTWRITE.
1328 tor_tls_shutdown(tor_tls_t
*tls
)
1333 tor_assert(tls
->ssl
);
1336 if (tls
->state
== TOR_TLS_ST_SENTCLOSE
) {
1337 /* If we've already called shutdown once to send a close message,
1338 * we read until the other side has closed too.
1341 r
= SSL_read(tls
->ssl
, buf
, 128);
1343 err
= tor_tls_get_error(tls
, r
, CATCH_ZERO
, "reading to shut down",
1345 if (err
== _TOR_TLS_ZERORETURN
) {
1346 tls
->state
= TOR_TLS_ST_GOTCLOSE
;
1347 /* fall through... */
1353 r
= SSL_shutdown(tls
->ssl
);
1355 /* If shutdown returns 1, the connection is entirely closed. */
1356 tls
->state
= TOR_TLS_ST_CLOSED
;
1357 return TOR_TLS_DONE
;
1359 err
= tor_tls_get_error(tls
, r
, CATCH_SYSCALL
|CATCH_ZERO
, "shutting down",
1361 if (err
== _TOR_TLS_SYSCALL
) {
1362 /* The underlying TCP connection closed while we were shutting down. */
1363 tls
->state
= TOR_TLS_ST_CLOSED
;
1364 return TOR_TLS_DONE
;
1365 } else if (err
== _TOR_TLS_ZERORETURN
) {
1366 /* The TLS connection says that it sent a shutdown record, but
1367 * isn't done shutting down yet. Make sure that this hasn't
1368 * happened before, then go back to the start of the function
1371 if (tls
->state
== TOR_TLS_ST_GOTCLOSE
||
1372 tls
->state
== TOR_TLS_ST_SENTCLOSE
) {
1373 log(LOG_WARN
, LD_NET
,
1374 "TLS returned \"half-closed\" value while already half-closed");
1375 return TOR_TLS_ERROR_MISC
;
1377 tls
->state
= TOR_TLS_ST_SENTCLOSE
;
1378 /* fall through ... */
1385 /** Return true iff this TLS connection is authenticated.
1388 tor_tls_peer_has_cert(tor_tls_t
*tls
)
1391 cert
= SSL_get_peer_certificate(tls
->ssl
);
1392 tls_log_errors(tls
, LOG_WARN
, "getting peer certificate");
1399 /** Warn that a certificate lifetime extends through a certain range. */
1401 log_cert_lifetime(X509
*cert
, const char *problem
)
1405 char *s1
=NULL
, *s2
=NULL
;
1407 time_t now
= time(NULL
);
1411 log_warn(LD_GENERAL
,
1412 "Certificate %s: is your system clock set incorrectly?",
1415 if (!(bio
= BIO_new(BIO_s_mem()))) {
1416 log_warn(LD_GENERAL
, "Couldn't allocate BIO!"); goto end
;
1418 if (!(ASN1_TIME_print(bio
, X509_get_notBefore(cert
)))) {
1419 tls_log_errors(NULL
, LOG_WARN
, "printing certificate lifetime");
1422 BIO_get_mem_ptr(bio
, &buf
);
1423 s1
= tor_strndup(buf
->data
, buf
->length
);
1425 (void)BIO_reset(bio
);
1426 if (!(ASN1_TIME_print(bio
, X509_get_notAfter(cert
)))) {
1427 tls_log_errors(NULL
, LOG_WARN
, "printing certificate lifetime");
1430 BIO_get_mem_ptr(bio
, &buf
);
1431 s2
= tor_strndup(buf
->data
, buf
->length
);
1433 strftime(mytime
, 32, "%b %d %H:%M:%S %Y GMT", tor_gmtime_r(&now
, &tm
));
1435 log_warn(LD_GENERAL
,
1436 "(certificate lifetime runs from %s through %s. Your time is %s.)",
1440 /* Not expected to get invoked */
1441 tls_log_errors(NULL
, LOG_WARN
, "getting certificate lifetime");
1450 /** Helper function: try to extract a link certificate and an identity
1451 * certificate from <b>tls</b>, and store them in *<b>cert_out</b> and
1452 * *<b>id_cert_out</b> respectively. Log all messages at level
1455 * Note that a reference is added to cert_out, so it needs to be
1456 * freed. id_cert_out doesn't. */
1458 try_to_extract_certs_from_tls(int severity
, tor_tls_t
*tls
,
1459 X509
**cert_out
, X509
**id_cert_out
)
1461 X509
*cert
= NULL
, *id_cert
= NULL
;
1462 STACK_OF(X509
) *chain
= NULL
;
1463 int num_in_chain
, i
;
1464 *cert_out
= *id_cert_out
= NULL
;
1466 if (!(cert
= SSL_get_peer_certificate(tls
->ssl
)))
1469 if (!(chain
= SSL_get_peer_cert_chain(tls
->ssl
)))
1471 num_in_chain
= sk_X509_num(chain
);
1472 /* 1 means we're receiving (server-side), and it's just the id_cert.
1473 * 2 means we're connecting (client-side), and it's both the link
1474 * cert and the id_cert.
1476 if (num_in_chain
< 1) {
1477 log_fn(severity
,LD_PROTOCOL
,
1478 "Unexpected number of certificates in chain (%d)",
1482 for (i
=0; i
<num_in_chain
; ++i
) {
1483 id_cert
= sk_X509_value(chain
, i
);
1484 if (X509_cmp(id_cert
, cert
) != 0)
1487 *id_cert_out
= id_cert
;
1490 /** If the provided tls connection is authenticated and has a
1491 * certificate chain that is currently valid and signed, then set
1492 * *<b>identity_key</b> to the identity certificate's key and return
1493 * 0. Else, return -1 and log complaints with log-level <b>severity</b>.
1496 tor_tls_verify(int severity
, tor_tls_t
*tls
, crypto_pk_env_t
**identity_key
)
1498 X509
*cert
= NULL
, *id_cert
= NULL
;
1499 EVP_PKEY
*id_pkey
= NULL
;
1503 *identity_key
= NULL
;
1505 try_to_extract_certs_from_tls(severity
, tls
, &cert
, &id_cert
);
1509 log_fn(severity
,LD_PROTOCOL
,"No distinct identity certificate found");
1512 if (!(id_pkey
= X509_get_pubkey(id_cert
)) ||
1513 X509_verify(cert
, id_pkey
) <= 0) {
1514 log_fn(severity
,LD_PROTOCOL
,"X509_verify on cert and pkey returned <= 0");
1515 tls_log_errors(tls
, severity
,"verifying certificate");
1519 rsa
= EVP_PKEY_get1_RSA(id_pkey
);
1522 *identity_key
= _crypto_new_pk_env_rsa(rsa
);
1530 EVP_PKEY_free(id_pkey
);
1532 /* This should never get invoked, but let's make sure in case OpenSSL
1533 * acts unexpectedly. */
1534 tls_log_errors(tls
, LOG_WARN
, "finishing tor_tls_verify");
1539 /** Check whether the certificate set on the connection <b>tls</b> is
1540 * expired or not-yet-valid, give or take <b>tolerance</b>
1541 * seconds. Return 0 for valid, -1 for failure.
1543 * NOTE: you should call tor_tls_verify before tor_tls_check_lifetime.
1546 tor_tls_check_lifetime(tor_tls_t
*tls
, int tolerance
)
1554 if (!(cert
= SSL_get_peer_certificate(tls
->ssl
)))
1557 t
= now
+ tolerance
;
1558 if (X509_cmp_time(X509_get_notBefore(cert
), &t
) > 0) {
1559 log_cert_lifetime(cert
, "not yet valid");
1562 t
= now
- tolerance
;
1563 if (X509_cmp_time(X509_get_notAfter(cert
), &t
) < 0) {
1564 log_cert_lifetime(cert
, "already expired");
1572 /* Not expected to get invoked */
1573 tls_log_errors(tls
, LOG_WARN
, "checking certificate lifetime");
1578 /** Return the number of bytes available for reading from <b>tls</b>.
1581 tor_tls_get_pending_bytes(tor_tls_t
*tls
)
1584 return SSL_pending(tls
->ssl
);
1587 /** If <b>tls</b> requires that the next write be of a particular size,
1588 * return that size. Otherwise, return 0. */
1590 tor_tls_get_forced_write_size(tor_tls_t
*tls
)
1592 return tls
->wantwrite_n
;
1595 /** Sets n_read and n_written to the number of bytes read and written,
1596 * respectively, on the raw socket used by <b>tls</b> since the last time this
1597 * function was called on <b>tls</b>. */
1599 tor_tls_get_n_raw_bytes(tor_tls_t
*tls
, size_t *n_read
, size_t *n_written
)
1603 r
= BIO_number_read(SSL_get_rbio(tls
->ssl
));
1604 /* We want the number of bytes actually for real written. Unfortunately,
1605 * sometimes OpenSSL replaces the wbio on tls->ssl with a buffering bio,
1606 * which makes the answer turn out wrong. Let's cope with that. Note
1607 * that this approach will fail if we ever replace tls->ssl's BIOs with
1608 * buffering bios for reasons of our own. As an alternative, we could
1609 * save the original BIO for tls->ssl in the tor_tls_t structure, but
1610 * that would be tempting fate. */
1611 wbio
= SSL_get_wbio(tls
->ssl
);
1612 if (wbio
->method
== BIO_f_buffer() && (tmpbio
= BIO_next(wbio
)) != NULL
)
1614 w
= BIO_number_written(wbio
);
1616 /* We are ok with letting these unsigned ints go "negative" here:
1617 * If we wrapped around, this should still give us the right answer, unless
1618 * we wrapped around by more than ULONG_MAX since the last time we called
1621 *n_read
= (size_t)(r
- tls
->last_read_count
);
1622 *n_written
= (size_t)(w
- tls
->last_write_count
);
1623 if (*n_read
> INT_MAX
|| *n_written
> INT_MAX
) {
1624 log_warn(LD_BUG
, "Preposterously large value in tor_tls_get_n_raw_bytes. "
1625 "r=%lu, last_read=%lu, w=%lu, last_written=%lu",
1626 r
, tls
->last_read_count
, w
, tls
->last_write_count
);
1628 tls
->last_read_count
= r
;
1629 tls
->last_write_count
= w
;
1632 /** Implement check_no_tls_errors: If there are any pending OpenSSL
1633 * errors, log an error message. */
1635 _check_no_tls_errors(const char *fname
, int line
)
1637 if (ERR_peek_error() == 0)
1639 log(LOG_WARN
, LD_CRYPTO
, "Unhandled OpenSSL errors found at %s:%d: ",
1640 tor_fix_source_file(fname
), line
);
1641 tls_log_errors(NULL
, LOG_WARN
, NULL
);
1644 /** Return true iff the initial TLS connection at <b>tls</b> did not use a v2
1645 * TLS handshake. Output is undefined if the handshake isn't finished. */
1647 tor_tls_used_v1_handshake(tor_tls_t
*tls
)
1649 if (tls
->isServer
) {
1650 #ifdef V2_HANDSHAKE_SERVER
1651 return ! tls
->wasV2Handshake
;
1654 #ifdef V2_HANDSHAKE_CLIENT
1655 return ! tls
->wasV2Handshake
;
1661 /** Examine the amount of memory used and available for buffers in <b>tls</b>.
1662 * Set *<b>rbuf_capacity</b> to the amount of storage allocated for the read
1663 * buffer and *<b>rbuf_bytes</b> to the amount actually used.
1664 * Set *<b>wbuf_capacity</b> to the amount of storage allocated for the write
1665 * buffer and *<b>wbuf_bytes</b> to the amount actually used. */
1667 tor_tls_get_buffer_sizes(tor_tls_t
*tls
,
1668 size_t *rbuf_capacity
, size_t *rbuf_bytes
,
1669 size_t *wbuf_capacity
, size_t *wbuf_bytes
)
1671 if (tls
->ssl
->s3
->rbuf
.buf
)
1672 *rbuf_capacity
= tls
->ssl
->s3
->rbuf
.len
;
1675 if (tls
->ssl
->s3
->wbuf
.buf
)
1676 *wbuf_capacity
= tls
->ssl
->s3
->wbuf
.len
;
1679 *rbuf_bytes
= tls
->ssl
->s3
->rbuf
.left
;
1680 *wbuf_bytes
= tls
->ssl
->s3
->wbuf
.left
;