Commit 25a8744d authored by Nick Mathewson's avatar Nick Mathewson 🌉
Browse files

r15223@tombo: nickm | 2007-12-07 23:41:21 -0500

 Aaand, do the code to enable the client side of the new TLS handshake.  There are some loose ends that need tying up in connection_or, and a lot of half-baked code to remove, and some special cases to test for, and lots and lots of testing to do, but that is what weekends are for.


svn:r12721
parent 88fa4417
......@@ -25,16 +25,23 @@ const char tortls_c_id[] =
#include <openssl/tls1.h>
#include <openssl/asn1.h>
#include <openssl/bio.h>
#include <openssl/opensslv.h>
#if OPENSSL_VERSION_NUMBER < 0x00907000l
#error "We require openssl >= 0.9.7"
#endif
#define CRYPTO_PRIVATE /* to import prototypes from crypto.h */
#include "./crypto.h"
#include "./tortls.h"
#include "./util.h"
#include "./log.h"
#include "crypto.h"
#include "tortls.h"
#include "util.h"
#include "log.h"
#include "container.h"
#include <string.h>
// #define V2_HANDSHAKE_SERVER
// #define V2_HANDSHAKE_CLIENT
/* Copied from or.h */
#define LEGAL_NICKNAME_CHARACTERS \
......@@ -62,10 +69,11 @@ struct tor_tls_t {
enum {
TOR_TLS_ST_HANDSHAKE, TOR_TLS_ST_OPEN, TOR_TLS_ST_GOTCLOSE,
TOR_TLS_ST_SENTCLOSE, TOR_TLS_ST_CLOSED, TOR_TLS_ST_RENEGOTIATE,
} state : 6; /**< The current SSL state, depending on which operations have
} state : 3; /**< The current SSL state, depending on which operations have
* completed successfully. */
unsigned int isServer:1; /**< True iff this is a server-side connection */
unsigned int hadCert:1; /**< Docdoc */
unsigned int wasV2Handshake:1; /**< DOCDOC */
size_t wantwrite_n; /**< 0 normally, >0 if we returned wantwrite last
* time. */
unsigned long last_write_count;
......@@ -358,22 +366,59 @@ tor_tls_create_certificate(crypto_pk_env_t *rsa,
return x509;
}
#ifdef EVERYONE_HAS_AES
/* Everybody is running OpenSSL 0.9.7 or later, so no backward compatibility
* is needed. */
#define CIPHER_LIST TLS1_TXT_DHE_RSA_WITH_AES_128_SHA
#elif defined(TLS1_TXT_DHE_RSA_WITH_AES_128_SHA)
/* Some people are running OpenSSL before 0.9.7, but we aren't.
* We can support AES and 3DES.
*/
#define CIPHER_LIST (TLS1_TXT_DHE_RSA_WITH_AES_128_SHA ":" \
SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA)
/* Note: for setting up your own private testing network with link
* crypto disabled, set your cipher list to SSL3_TXT_RSA_NULL_SHA.
* If you do this, you won't be able to communicate with any of the
* "real" Tors, though. */
#define SERVER_CIPHER_LIST \
(TLS1_TXT_DHE_RSA_WITH_AES_256_SHA ":" \
TLS1_TXT_DHE_RSA_WITH_AES_128_SHA ":" \
SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA)
/* Note: for setting up your own private testing network with link crypto
* disabled, set the cipher lists to your cipher list to
* SSL3_TXT_RSA_NULL_SHA. If you do this, you won't be able to communicate
* with any of the "real" Tors, though. */
#if OPENSSL_VERSION_NUMBER >= 0x00908000l
#define CLIENT_CIPHER_LIST \
(TLS1_TXT_ECDHE_ECDSA_WITH_AES_256_CBC_SHA ":" \
TLS1_TXT_ECDHE_RSA_WITH_AES_256_CBC_SHA ":" \
TLS1_TXT_DHE_RSA_WITH_AES_256_SHA ":" \
TLS1_TXT_DHE_DSS_WITH_AES_256_SHA ":" \
TLS1_TXT_ECDH_RSA_WITH_AES_256_CBC_SHA ":" \
TLS1_TXT_ECDH_ECDSA_WITH_AES_256_CBC_SHA ":" \
TLS1_TXT_RSA_WITH_AES_256_SHA ":" \
TLS1_TXT_ECDHE_ECDSA_WITH_RC4_128_SHA ":" \
TLS1_TXT_ECDHE_ECDSA_WITH_AES_128_CBC_SHA ":" \
TLS1_TXT_ECDHE_RSA_WITH_RC4_128_SHA ":" \
TLS1_TXT_ECDHE_RSA_WITH_AES_128_CBC_SHA ":" \
TLS1_TXT_DHE_RSA_WITH_AES_128_SHA ":" \
TLS1_TXT_DHE_DSS_WITH_AES_128_SHA ":" \
TLS1_TXT_ECDH_RSA_WITH_RC4_128_SHA":" \
TLS1_TXT_ECDH_RSA_WITH_AES_128_CBC_SHA":" \
TLS1_TXT_ECDH_ECDSA_WITH_RC4_128_SHA ":" \
TLS1_TXT_ECDH_ECDSA_WITH_AES_128_CBC_SHA ":" \
SSL3_TXT_RSA_RC4_128_MD5 ":" \
SSL3_TXT_RSA_RC4_128_SHA ":" \
TLS1_TXT_RSA_WITH_AES_128_SHA ":" \
TLS1_TXT_ECDHE_ECDSA_WITH_DES_192_CBC3_SHA ":" \
TLS1_TXT_ECDHE_RSA_WITH_DES_192_CBC3_SHA ":" \
SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA ":" \
SSL3_TXT_EDH_DSS_DES_192_CBC3_SHA ":" \
TLS1_TXT_ECDH_RSA_WITH_DES_192_CBC3_SHA ":" \
TLS1_TXT_ECDH_ECDSA_WITH_DES_192_CBC3_SHA ":" \
SSL3_TXT_RSA_FIPS_WITH_3DES_EDE_CBC_SHA ":" \
SSL3_TXT_RSA_DES_192_CBC3_SHA)
#else
#error "Tor requires OpenSSL version 0.9.7 or later, for AES support."
/* Ug. We don't have as many ciphers with openssl 0.9.7 as we'd like. Fix
* this list into something that sucks less. */
#define CLIENT_CIPHER_LIST \
(TLS1_TXT_DHE_RSA_WITH_AES_256_SHA ":" \
TLS1_TXT_DHE_RSA_WITH_AES_128_SHA ":" \
SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA ":" \
SSL3_TXT_RSA_RC4_128_SHA)
#endif
#ifndef V2_HANDSHAKE_CLIENT
#undef CLIENT_CIPHER_LIST
#define CLIENT_CIPHER_LIST (TLS1_TXT_DHE_RSA_WITH_AES_128_SHA ":" \
SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA)
#endif
/** DOCDOC */
......@@ -454,8 +499,6 @@ tor_tls_context_new(crypto_pk_env_t *identity, const char *nickname,
SSL_CTX_set_options(result->ctx, SSL_OP_NO_SSLv2);
#endif
SSL_CTX_set_options(result->ctx, SSL_OP_SINGLE_DH_USE);
if (!SSL_CTX_set_cipher_list(result->ctx, CIPHER_LIST))
goto error;
if (cert && !SSL_CTX_use_certificate(result->ctx,cert))
goto error;
X509_free(cert); /* We just added a reference to cert. */
......@@ -517,26 +560,21 @@ tor_tls_context_new(crypto_pk_env_t *identity, const char *nickname,
}
#ifdef V2_HANDSHAKE_SERVER
static void
tor_tls_server_info_callback(const SSL *ssl, int type, int val)
/** DOCDOC */
static int
tor_tls_client_is_using_v2_ciphers(const SSL *ssl)
{
int all_ciphers_in_v1_list = 1;
int i;
SSL_SESSION *session;
(void) val;
if (type != SSL_CB_ACCEPT_LOOP)
return;
if (ssl->state != SSL3_ST_SW_SRVR_HELLO_A)
return;
/* If we reached this point, we just got a client hello. See if there is
* a cipher list. */
if (!(session = SSL_get_session(ssl))) {
log_warn(LD_NET, "No session on TLS?");
return;
return 0;
}
if (!session->ciphers) {
log_warn(LD_NET, "No ciphers on session");
return;
return 0;
}
/* Now we need to see if there are any ciphers whose presence means we're
* dealing with an updated Tor. */
......@@ -549,12 +587,39 @@ tor_tls_server_info_callback(const SSL *ssl, int type, int val)
strcmp(ciphername, "(NONE)")) {
/* XXXX should be ld_debug */
log_info(LD_NET, "Got a non-version-1 cipher called '%s'",ciphername);
all_ciphers_in_v1_list = 0;
break;
// return 1;
goto dump_list;
}
}
return 0;
dump_list:
{
smartlist_t *elts = smartlist_create();
char *s;
for (i = 0; i < sk_SSL_CIPHER_num(session->ciphers); ++i) {
SSL_CIPHER *cipher = sk_SSL_CIPHER_value(session->ciphers, i);
const char *ciphername = SSL_CIPHER_get_name(cipher);
smartlist_add(elts, (char*)ciphername);
}
s = smartlist_join_strings(elts, ":", 0, NULL);
log_info(LD_NET, "Got a non-version-1 cipher list. It is: '%s'", s);
tor_free(s);
smartlist_free(elts);
}
return 1;
}
if (!all_ciphers_in_v1_list) {
/** DOCDOC */
static void
tor_tls_server_info_callback(const SSL *ssl, int type, int val)
{
(void) val;
if (type != SSL_CB_ACCEPT_LOOP)
return;
if (ssl->state != SSL3_ST_SW_SRVR_HELLO_A)
return;
if (tor_tls_client_is_using_v2_ciphers(ssl)) {
/* Yes, we're casting away the const from ssl. This is very naughty of us.
* Let's hope openssl doesn't notice! */
......@@ -581,6 +646,12 @@ tor_tls_new(int sock, int isServer)
tor_free(result);
return NULL;
}
if (!SSL_set_cipher_list(result->ssl,
isServer ? SERVER_CIPHER_LIST : CLIENT_CIPHER_LIST)) {
SSL_free(result->ssl);
tor_free(result);
return NULL;
}
result->socket = sock;
#ifdef USE_BSOCKETS
bio = BIO_new_bsocket(sock, BIO_NOCLOSE);
......@@ -742,7 +813,31 @@ tor_tls_handshake(tor_tls_t *tls)
if (tls->isServer) {
SSL_set_info_callback(tls->ssl, NULL);
SSL_set_verify(tls->ssl, SSL_VERIFY_NONE, always_accept_verify_cb);
/* There doesn't seem to be a clear OpenSSL API to clear mode flags. */
tls->ssl->mode &= ~SSL_MODE_NO_AUTO_CHAIN;
#ifdef V2_HANDSHAKE_SERVER
if (tor_tls_client_is_using_v2_ciphers(tls->ssl)) {
/* This check is redundant, but back when we did it in the callback,
* we didn't have access to the tor_tls_t struct. We could make some
* kind of static map linking SSLs to tor_tls_ts, but that way lies
* sadness. */
tls->wasV2Handshake = 1;
} else {
tls->wasV2Handshake = 0;
}
#endif
} else {
#ifdef V2_HANDSHAKE_CLIENT
/* If we got no ID cert, we're a v2 handshake. */
X509 *cert = SSL_get_peer_certificate(tls->ssl);/*XXXX020 refcnt?*/
STACK_OF(X509) *chain = SSL_get_peer_cert_chain(tls->ssl);
int n_certs = sk_X509_num(chain);
if (n_certs > 1 || (n_certs == 1 && cert != sk_X509_value(chain, 0)))
tls->wasV2Handshake = 0;
else
tls->wasV2Handshake = 1;
#endif
SSL_set_cipher_list(tls->ssl, SERVER_CIPHER_LIST);
}
}
return r;
......@@ -1238,7 +1333,15 @@ _check_no_tls_errors(const char *fname, int line)
int
tor_tls_used_v1_handshake(tor_tls_t *tls)
{
(void)tls;
if (tls->isServer) {
#ifdef V2_HANDSHAKE_SERVER
return ! tls->wasV2Handshake;
#endif
} else {
#ifdef V2_HANDSHAKE_CLIENT
return ! tls->wasV2Handshake;
#endif
}
return 1;
}
......
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