commit db1c1dba34545c9b96f9ec4c01338caeaeeb0433 Merge: 4aa02d3c7 1710f4bbd Author: Nick Mathewson nickm@torproject.org Date: Thu Apr 4 11:26:33 2019 -0400
Merge branch 'bug30021_029' into bug30021_035
changes/bug30021 | 8 ++++++++ src/lib/tls/tortls_openssl.c | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-)
diff --cc src/lib/tls/tortls_openssl.c index e702cb9df,000000000..80b0df301 mode 100644,000000..100644 --- a/src/lib/tls/tortls_openssl.c +++ b/src/lib/tls/tortls_openssl.c @@@ -1,1795 -1,0 +1,1795 @@@ +/* Copyright (c) 2003, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file tortls.c + * \brief Wrapper functions to present a consistent interface to + * TLS, SSL, and X.509 functions from OpenSSL. + **/ + +/* (Unlike other tor functions, these + * are prefixed with tor_ in order to avoid conflicting with OpenSSL + * functions and variables.) + */ + +#include "orconfig.h" + +#define TORTLS_PRIVATE +#define TORTLS_OPENSSL_PRIVATE +#define TOR_X509_PRIVATE + +#ifdef _WIN32 + /* We need to include these here, or else the dtls1.h header will include + * <winsock.h> and mess things up, in at least some openssl versions. */ + #include <winsock2.h> + #include <ws2tcpip.h> +#endif + +#include "lib/crypt_ops/crypto_cipher.h" +#include "lib/crypt_ops/crypto_rand.h" +#include "lib/crypt_ops/crypto_dh.h" +#include "lib/crypt_ops/crypto_util.h" +#include "lib/crypt_ops/compat_openssl.h" +#include "lib/tls/x509.h" +#include "lib/tls/x509_internal.h" + +/* Some versions of OpenSSL declare SSL_get_selected_srtp_profile twice in + * srtp.h. Suppress the GCC warning so we can build with -Wredundant-decl. */ +DISABLE_GCC_WARNING(redundant-decls) + +#include <openssl/opensslv.h> + +#ifdef OPENSSL_NO_EC +#error "We require OpenSSL with ECC support" +#endif + +#include <openssl/ssl.h> +#include <openssl/ssl3.h> +#include <openssl/err.h> +#include <openssl/tls1.h> +#include <openssl/asn1.h> +#include <openssl/bio.h> +#include <openssl/bn.h> +#include <openssl/rsa.h> + +ENABLE_GCC_WARNING(redundant-decls) + +#include "lib/tls/tortls.h" +#include "lib/tls/tortls_st.h" +#include "lib/tls/tortls_internal.h" +#include "lib/log/log.h" +#include "lib/log/util_bug.h" +#include "lib/container/smartlist.h" +#include "lib/string/compat_string.h" +#include "lib/string/printf.h" +#include "lib/net/socket.h" +#include "lib/intmath/cmp.h" +#include "lib/ctime/di_ops.h" +#include "lib/encoding/time_fmt.h" + +#include <stdlib.h> +#include <string.h> + +#include "lib/arch/bytes.h" + +/* Copied from or.h */ +#define LEGAL_NICKNAME_CHARACTERS \ + "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" + +#define ADDR(tls) (((tls) && (tls)->address) ? tls->address : "peer") + +#if OPENSSL_VERSION_NUMBER < OPENSSL_V(1,0,0,'f') +/* This is a version of OpenSSL before 1.0.0f. It does not have + * the CVE-2011-4576 fix, and as such it can't use RELEASE_BUFFERS and + * SSL3 safely at the same time. + */ +#define DISABLE_SSL3_HANDSHAKE +#endif /* OPENSSL_VERSION_NUMBER < OPENSSL_V(1,0,0,'f') */ + +/* We redefine these so that we can run correctly even if the vendor gives us + * a version of OpenSSL that does not match its header files. (Apple: I am + * looking at you.) + */ +#ifndef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION +#define SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0x00040000L +#endif +#ifndef SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION +#define SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0x0010 +#endif + +/** Set to true iff openssl bug 7712 has been detected. */ +static int openssl_bug_7712_is_present = 0; + +/** Return values for tor_tls_classify_client_ciphers. + * + * @{ + */ +/** An error occurred when examining the client ciphers */ +#define CIPHERS_ERR -1 +/** The client cipher list indicates that a v1 handshake was in use. */ +#define CIPHERS_V1 1 +/** The client cipher list indicates that the client is using the v2 or the + * v3 handshake, but that it is (probably!) lying about what ciphers it + * supports */ +#define CIPHERS_V2 2 +/** The client cipher list indicates that the client is using the v2 or the + * v3 handshake, and that it is telling the truth about what ciphers it + * supports */ +#define CIPHERS_UNRESTRICTED 3 +/** @} */ + +/** The ex_data index in which we store a pointer to an SSL object's + * corresponding tor_tls_t object. */ +STATIC int tor_tls_object_ex_data_index = -1; + +/** Helper: Allocate tor_tls_object_ex_data_index. */ +void +tor_tls_allocate_tor_tls_object_ex_data_index(void) +{ + if (tor_tls_object_ex_data_index == -1) { + tor_tls_object_ex_data_index = + SSL_get_ex_new_index(0, NULL, NULL, NULL, NULL); + tor_assert(tor_tls_object_ex_data_index != -1); + } +} + +/** Helper: given a SSL* pointer, return the tor_tls_t object using that + * pointer. */ +tor_tls_t * +tor_tls_get_by_ssl(const SSL *ssl) +{ + tor_tls_t *result = SSL_get_ex_data(ssl, tor_tls_object_ex_data_index); + if (result) + tor_assert(result->magic == TOR_TLS_MAGIC); + return result; +} + +/** True iff tor_tls_init() has been called. */ +static int tls_library_is_initialized = 0; + +/* Module-internal error codes. */ +#define TOR_TLS_SYSCALL_ (MIN_TOR_TLS_ERROR_VAL_ - 2) +#define TOR_TLS_ZERORETURN_ (MIN_TOR_TLS_ERROR_VAL_ - 1) + +/** Write a description of the current state of <b>tls</b> into the + * <b>sz</b>-byte buffer at <b>buf</b>. */ +void +tor_tls_get_state_description(tor_tls_t *tls, char *buf, size_t sz) +{ + const char *ssl_state; + const char *tortls_state; + + if (PREDICT_UNLIKELY(!tls || !tls->ssl)) { + strlcpy(buf, "(No SSL object)", sz); + return; + } + + ssl_state = SSL_state_string_long(tls->ssl); + switch (tls->state) { +#define CASE(st) case TOR_TLS_ST_##st: tortls_state = " in "#st ; break + CASE(HANDSHAKE); + CASE(OPEN); + CASE(GOTCLOSE); + CASE(SENTCLOSE); + CASE(CLOSED); + CASE(RENEGOTIATE); +#undef CASE + case TOR_TLS_ST_BUFFEREVENT: + tortls_state = ""; + break; + default: + tortls_state = " in unknown TLS state"; + break; + } + + tor_snprintf(buf, sz, "%s%s", ssl_state, tortls_state); +} + +/** Log a single error <b>err</b> as returned by ERR_get_error(), which was + * received while performing an operation <b>doing</b> on <b>tls</b>. Log + * the message at <b>severity</b>, in log domain <b>domain</b>. */ +void +tor_tls_log_one_error(tor_tls_t *tls, unsigned long err, + int severity, int domain, const char *doing) +{ + const char *state = NULL, *addr; + const char *msg, *lib, *func; + + state = (tls && tls->ssl)?SSL_state_string_long(tls->ssl):"---"; + + addr = tls ? tls->address : NULL; + + /* Some errors are known-benign, meaning they are the fault of the other + * side of the connection. The caller doesn't know this, so override the + * priority for those cases. */ + switch (ERR_GET_REASON(err)) { + case SSL_R_HTTP_REQUEST: + case SSL_R_HTTPS_PROXY_REQUEST: + case SSL_R_RECORD_LENGTH_MISMATCH: +#ifndef OPENSSL_1_1_API + case SSL_R_RECORD_TOO_LARGE: +#endif + case SSL_R_UNKNOWN_PROTOCOL: + case SSL_R_UNSUPPORTED_PROTOCOL: + severity = LOG_INFO; + break; + default: + break; + } + + msg = (const char*)ERR_reason_error_string(err); + lib = (const char*)ERR_lib_error_string(err); + func = (const char*)ERR_func_error_string(err); + if (!msg) msg = "(null)"; + if (!lib) lib = "(null)"; + if (!func) func = "(null)"; + if (doing) { + tor_log(severity, domain, "TLS error while %s%s%s: %s (in %s:%s:%s)", + doing, addr?" with ":"", addr?addr:"", + msg, lib, func, state); + } else { + tor_log(severity, domain, "TLS error%s%s: %s (in %s:%s:%s)", + addr?" with ":"", addr?addr:"", + msg, lib, func, state); + } +} + +/** Log all pending tls errors at level <b>severity</b> in log domain + * <b>domain</b>. Use <b>doing</b> to describe our current activities. + */ +void +tls_log_errors(tor_tls_t *tls, int severity, int domain, const char *doing) +{ + unsigned long err; + + while ((err = ERR_get_error()) != 0) { + tor_tls_log_one_error(tls, err, severity, domain, doing); + } +} + +#define CATCH_SYSCALL 1 +#define CATCH_ZERO 2 + +/** Given a TLS object and the result of an SSL_* call, use + * SSL_get_error to determine whether an error has occurred, and if so + * which one. Return one of TOR_TLS_{DONE|WANTREAD|WANTWRITE|ERROR}. + * If extra&CATCH_SYSCALL is true, return TOR_TLS_SYSCALL_ instead of + * reporting syscall errors. If extra&CATCH_ZERO is true, return + * TOR_TLS_ZERORETURN_ instead of reporting zero-return errors. + * + * If an error has occurred, log it at level <b>severity</b> and describe the + * current action as <b>doing</b>. + */ +int +tor_tls_get_error(tor_tls_t *tls, int r, int extra, + const char *doing, int severity, int domain) +{ + int err = SSL_get_error(tls->ssl, r); + int tor_error = TOR_TLS_ERROR_MISC; + switch (err) { + case SSL_ERROR_NONE: + return TOR_TLS_DONE; + case SSL_ERROR_WANT_READ: + return TOR_TLS_WANTREAD; + case SSL_ERROR_WANT_WRITE: + return TOR_TLS_WANTWRITE; + case SSL_ERROR_SYSCALL: + if (extra&CATCH_SYSCALL) + return TOR_TLS_SYSCALL_; + if (r == 0) { + tor_log(severity, LD_NET, "TLS error: unexpected close while %s (%s)", + doing, SSL_state_string_long(tls->ssl)); + tor_error = TOR_TLS_ERROR_IO; + } else { + int e = tor_socket_errno(tls->socket); + tor_log(severity, LD_NET, + "TLS error: <syscall error while %s> (errno=%d: %s; state=%s)", + doing, e, tor_socket_strerror(e), + SSL_state_string_long(tls->ssl)); + tor_error = tor_errno_to_tls_error(e); + } + tls_log_errors(tls, severity, domain, doing); + return tor_error; + case SSL_ERROR_ZERO_RETURN: + if (extra&CATCH_ZERO) + return TOR_TLS_ZERORETURN_; + tor_log(severity, LD_NET, "TLS connection closed while %s in state %s", + doing, SSL_state_string_long(tls->ssl)); + tls_log_errors(tls, severity, domain, doing); + return TOR_TLS_CLOSE; + default: + tls_log_errors(tls, severity, domain, doing); + return TOR_TLS_ERROR_MISC; + } +} + +/** Initialize OpenSSL, unless it has already been initialized. + */ +void +tor_tls_init(void) +{ + check_no_tls_errors(); + + if (!tls_library_is_initialized) { +#ifdef OPENSSL_1_1_API + OPENSSL_init_ssl(OPENSSL_INIT_LOAD_SSL_STRINGS, NULL); +#else + SSL_library_init(); + SSL_load_error_strings(); +#endif + +#if (SIZEOF_VOID_P >= 8 && \ + OPENSSL_VERSION_NUMBER >= OPENSSL_V_SERIES(1,0,1)) + long version = OpenSSL_version_num(); + + /* LCOV_EXCL_START : we can't test these lines on the same machine */ + if (version >= OPENSSL_V_SERIES(1,0,1)) { + /* Warn if we could *almost* be running with much faster ECDH. + If we're built for a 64-bit target, using OpenSSL 1.0.1, but we + don't have one of the built-in __uint128-based speedups, we are + just one build operation away from an accelerated handshake. + + (We could be looking at OPENSSL_NO_EC_NISTP_64_GCC_128 instead of + doing this test, but that gives compile-time options, not runtime + behavior.) + */ + EC_KEY *key = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1); + const EC_GROUP *g = key ? EC_KEY_get0_group(key) : NULL; + const EC_METHOD *m = g ? EC_GROUP_method_of(g) : NULL; + const int warn = (m == EC_GFp_simple_method() || + m == EC_GFp_mont_method() || + m == EC_GFp_nist_method()); + EC_KEY_free(key); + + if (warn) + log_notice(LD_GENERAL, "We were built to run on a 64-bit CPU, with " + "OpenSSL 1.0.1 or later, but with a version of OpenSSL " + "that apparently lacks accelerated support for the NIST " + "P-224 and P-256 groups. Building openssl with such " + "support (using the enable-ec_nistp_64_gcc_128 option " + "when configuring it) would make ECDH much faster."); + } + /* LCOV_EXCL_STOP */ +#endif /* (SIZEOF_VOID_P >= 8 && ... */ + + tor_tls_allocate_tor_tls_object_ex_data_index(); + + tls_library_is_initialized = 1; + } +} + +/** We need to give OpenSSL a callback to verify certificates. This is + * it: We always accept peer certs and complete the handshake. We + * don't validate them until later. + */ +int +always_accept_verify_cb(int preverify_ok, + X509_STORE_CTX *x509_ctx) +{ + (void) preverify_ok; + (void) x509_ctx; + return 1; +} + +/** List of ciphers that servers should select from when the client might be + * claiming extra unsupported ciphers in order to avoid fingerprinting. */ +static const char SERVER_CIPHER_LIST[] = +#ifdef TLS1_3_TXT_AES_128_GCM_SHA256 + /* This one can never actually get selected, since if the client lists it, + * we will assume that the client is honest, and not use this list. + * Nonetheless we list it if it's available, so that the server doesn't + * conclude that it has no valid ciphers if it's running with TLS1.3. + */ + TLS1_3_TXT_AES_128_GCM_SHA256 ":" +#endif + TLS1_TXT_DHE_RSA_WITH_AES_256_SHA ":" + TLS1_TXT_DHE_RSA_WITH_AES_128_SHA; + +/** List of ciphers that servers should select from when we actually have + * our choice of what cipher to use. */ +static const char UNRESTRICTED_SERVER_CIPHER_LIST[] = + /* Here are the TLS 1.3 ciphers we like, in the order we prefer. */ +#ifdef TLS1_3_TXT_AES_256_GCM_SHA384 + TLS1_3_TXT_AES_256_GCM_SHA384 ":" +#endif +#ifdef TLS1_3_TXT_CHACHA20_POLY1305_SHA256 + TLS1_3_TXT_CHACHA20_POLY1305_SHA256 ":" +#endif +#ifdef TLS1_3_TXT_AES_128_GCM_SHA256 + TLS1_3_TXT_AES_128_GCM_SHA256 ":" +#endif +#ifdef TLS1_3_TXT_AES_128_CCM_SHA256 + TLS1_3_TXT_AES_128_CCM_SHA256 ":" +#endif + + /* This list is autogenerated with the gen_server_ciphers.py script; + * don't hand-edit it. */ +#ifdef TLS1_TXT_ECDHE_RSA_WITH_AES_256_GCM_SHA384 + TLS1_TXT_ECDHE_RSA_WITH_AES_256_GCM_SHA384 ":" +#endif +#ifdef TLS1_TXT_ECDHE_RSA_WITH_AES_128_GCM_SHA256 + TLS1_TXT_ECDHE_RSA_WITH_AES_128_GCM_SHA256 ":" +#endif +#ifdef TLS1_TXT_ECDHE_RSA_WITH_AES_256_SHA384 + TLS1_TXT_ECDHE_RSA_WITH_AES_256_SHA384 ":" +#endif +#ifdef TLS1_TXT_ECDHE_RSA_WITH_AES_128_SHA256 + TLS1_TXT_ECDHE_RSA_WITH_AES_128_SHA256 ":" +#endif +#ifdef TLS1_TXT_ECDHE_RSA_WITH_AES_256_CBC_SHA + TLS1_TXT_ECDHE_RSA_WITH_AES_256_CBC_SHA ":" +#endif +#ifdef TLS1_TXT_ECDHE_RSA_WITH_AES_128_CBC_SHA + TLS1_TXT_ECDHE_RSA_WITH_AES_128_CBC_SHA ":" +#endif +#ifdef TLS1_TXT_DHE_RSA_WITH_AES_256_GCM_SHA384 + TLS1_TXT_DHE_RSA_WITH_AES_256_GCM_SHA384 ":" +#endif +#ifdef TLS1_TXT_DHE_RSA_WITH_AES_128_GCM_SHA256 + TLS1_TXT_DHE_RSA_WITH_AES_128_GCM_SHA256 ":" +#endif +#ifdef TLS1_TXT_DHE_RSA_WITH_AES_256_CCM + TLS1_TXT_DHE_RSA_WITH_AES_256_CCM ":" +#endif +#ifdef TLS1_TXT_DHE_RSA_WITH_AES_128_CCM + TLS1_TXT_DHE_RSA_WITH_AES_128_CCM ":" +#endif +#ifdef TLS1_TXT_DHE_RSA_WITH_AES_256_SHA256 + TLS1_TXT_DHE_RSA_WITH_AES_256_SHA256 ":" +#endif +#ifdef TLS1_TXT_DHE_RSA_WITH_AES_128_SHA256 + TLS1_TXT_DHE_RSA_WITH_AES_128_SHA256 ":" +#endif + /* Required */ + TLS1_TXT_DHE_RSA_WITH_AES_256_SHA ":" + /* Required */ + TLS1_TXT_DHE_RSA_WITH_AES_128_SHA ":" +#ifdef TLS1_TXT_ECDHE_RSA_WITH_CHACHA20_POLY1305 + TLS1_TXT_ECDHE_RSA_WITH_CHACHA20_POLY1305 ":" +#endif +#ifdef TLS1_TXT_DHE_RSA_WITH_CHACHA20_POLY1305 + TLS1_TXT_DHE_RSA_WITH_CHACHA20_POLY1305 +#endif + ; + +/* Note: to set up your own private testing network with link crypto + * disabled, set your Tors' 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 CIPHER(id, name) name ":" +#define XCIPHER(id, name) +/** List of ciphers that clients should advertise, omitting items that + * our OpenSSL doesn't know about. */ +static const char CLIENT_CIPHER_LIST[] = +#include "ciphers.inc" + /* Tell it not to use SSLv2 ciphers, so that it can select an SSLv3 version + * of any cipher we say. */ + "!SSLv2" + ; +#undef CIPHER +#undef XCIPHER + +/** Return true iff the other side of <b>tls</b> has authenticated to us, and + * the key certified in <b>cert</b> is the same as the key they used to do it. + */ +MOCK_IMPL(int, +tor_tls_cert_matches_key,(const tor_tls_t *tls, const tor_x509_cert_t *cert)) +{ + tor_x509_cert_t *peer = tor_tls_get_peer_cert((tor_tls_t *)tls); + if (!peer) + return 0; + + X509 *peercert = peer->cert; + EVP_PKEY *link_key = NULL, *cert_key = NULL; + int result; + + link_key = X509_get_pubkey(peercert); + cert_key = X509_get_pubkey(cert->cert); + + result = link_key && cert_key && EVP_PKEY_cmp(cert_key, link_key) == 1; + + tor_x509_cert_free(peer); + if (link_key) + EVP_PKEY_free(link_key); + if (cert_key) + EVP_PKEY_free(cert_key); + + return result; +} + +void +tor_tls_context_impl_free_(struct ssl_ctx_st *ctx) +{ + if (!ctx) + return; + SSL_CTX_free(ctx); +} + +/** The group we should use for ecdhe when none was selected. */ +#define NID_tor_default_ecdhe_group NID_X9_62_prime256v1 + +/** Create a new TLS context for use with Tor TLS handshakes. + * <b>identity</b> should be set to the identity key used to sign the + * certificate. + */ +tor_tls_context_t * +tor_tls_context_new(crypto_pk_t *identity, unsigned int key_lifetime, + unsigned flags, int is_client) +{ + EVP_PKEY *pkey = NULL; + tor_tls_context_t *result = NULL; + + tor_tls_init(); + + result = tor_malloc_zero(sizeof(tor_tls_context_t)); + result->refcnt = 1; + + if (! is_client) { + if (tor_tls_context_init_certificates(result, identity, key_lifetime, + flags) < 0) { + goto error; + } + } + +#if 0 + /* Tell OpenSSL to only use TLS1. This may have subtly different results + * from SSLv23_method() with SSLv2 and SSLv3 disabled, so we need to do some + * investigation before we consider adjusting it. It should be compatible + * with existing Tors. */ + if (!(result->ctx = SSL_CTX_new(TLSv1_method()))) + goto error; +#endif /* 0 */ + + /* Tell OpenSSL to use TLS 1.0 or later but not SSL2 or SSL3. */ +#ifdef HAVE_TLS_METHOD + if (!(result->ctx = SSL_CTX_new(TLS_method()))) + goto error; +#else + if (!(result->ctx = SSL_CTX_new(SSLv23_method()))) + goto error; +#endif /* defined(HAVE_TLS_METHOD) */ + +#ifdef HAVE_SSL_CTX_SET_SECURITY_LEVEL + /* Level 1 re-enables RSA1024 and DH1024 for compatibility with old tors */ + SSL_CTX_set_security_level(result->ctx, 1); +#endif + + SSL_CTX_set_options(result->ctx, SSL_OP_NO_SSLv2); + SSL_CTX_set_options(result->ctx, SSL_OP_NO_SSLv3); + + /* Prefer the server's ordering of ciphers: the client's ordering has + * historically been chosen for fingerprinting resistance. */ + SSL_CTX_set_options(result->ctx, SSL_OP_CIPHER_SERVER_PREFERENCE); + + /* Disable TLS tickets if they're supported. We never want to use them; + * using them can make our perfect forward secrecy a little worse, *and* + * create an opportunity to fingerprint us (since it's unusual to use them + * with TLS sessions turned off). + * + * In 0.2.4, clients advertise support for them though, to avoid a TLS + * distinguishability vector. This can give us worse PFS, though, if we + * get a server that doesn't set SSL_OP_NO_TICKET. With luck, there will + * be few such servers by the time 0.2.4 is more stable. + */ +#ifdef SSL_OP_NO_TICKET + if (! is_client) { + SSL_CTX_set_options(result->ctx, SSL_OP_NO_TICKET); + } +#endif + + SSL_CTX_set_options(result->ctx, SSL_OP_SINGLE_DH_USE); + SSL_CTX_set_options(result->ctx, SSL_OP_SINGLE_ECDH_USE); + +#ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION + SSL_CTX_set_options(result->ctx, + SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION); +#endif + /* Yes, we know what we are doing here. No, we do not treat a renegotiation + * as authenticating any earlier-received data. + */ + { + SSL_CTX_set_options(result->ctx, + SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION); + } + + /* Don't actually allow compression; it uses RAM and time, it makes TLS + * vulnerable to CRIME-style attacks, and most of the data we transmit over + * TLS is encrypted (and therefore uncompressible) anyway. */ +#ifdef SSL_OP_NO_COMPRESSION + SSL_CTX_set_options(result->ctx, SSL_OP_NO_COMPRESSION); +#endif +#if OPENSSL_VERSION_NUMBER < OPENSSL_V_SERIES(1,1,0) +#ifndef OPENSSL_NO_COMP + if (result->ctx->comp_methods) + result->ctx->comp_methods = NULL; +#endif +#endif /* OPENSSL_VERSION_NUMBER < OPENSSL_V_SERIES(1,1,0) */ + +#ifdef SSL_MODE_RELEASE_BUFFERS + SSL_CTX_set_mode(result->ctx, SSL_MODE_RELEASE_BUFFERS); +#endif + if (! is_client) { + if (result->my_link_cert && + !SSL_CTX_use_certificate(result->ctx, + result->my_link_cert->cert)) { + goto error; + } + if (result->my_id_cert) { + X509_STORE *s = SSL_CTX_get_cert_store(result->ctx); + tor_assert(s); + X509_STORE_add_cert(s, result->my_id_cert->cert); + } + } + SSL_CTX_set_session_cache_mode(result->ctx, SSL_SESS_CACHE_OFF); + if (!is_client) { + tor_assert(result->link_key); + if (!(pkey = crypto_pk_get_openssl_evp_pkey_(result->link_key,1))) + goto error; + if (!SSL_CTX_use_PrivateKey(result->ctx, pkey)) + goto error; + EVP_PKEY_free(pkey); + pkey = NULL; + if (!SSL_CTX_check_private_key(result->ctx)) + goto error; + } + + { + DH *dh = crypto_dh_new_openssl_tls(); + tor_assert(dh); + SSL_CTX_set_tmp_dh(result->ctx, dh); + DH_free(dh); + } +/* We check for this function in two ways, since it might be either a symbol + * or a macro. */ +#if defined(SSL_CTX_set1_groups_list) || defined(HAVE_SSL_CTX_SET1_GROUPS_LIST) + { + const char *list; + if (flags & TOR_TLS_CTX_USE_ECDHE_P224) + list = "P-224:P-256"; + else if (flags & TOR_TLS_CTX_USE_ECDHE_P256) + list = "P-256:P-224"; + else + list = "P-256:P-224"; + int r = (int) SSL_CTX_set1_groups_list(result->ctx, list); + if (r < 0) + goto error; + } +#else + if (! is_client) { + int nid; + EC_KEY *ec_key; + if (flags & TOR_TLS_CTX_USE_ECDHE_P224) + nid = NID_secp224r1; + else if (flags & TOR_TLS_CTX_USE_ECDHE_P256) + nid = NID_X9_62_prime256v1; + else + nid = NID_tor_default_ecdhe_group; + /* Use P-256 for ECDHE. */ + ec_key = EC_KEY_new_by_curve_name(nid); + if (ec_key != NULL) /*XXXX Handle errors? */ + SSL_CTX_set_tmp_ecdh(result->ctx, ec_key); + EC_KEY_free(ec_key); + } +#endif + SSL_CTX_set_verify(result->ctx, SSL_VERIFY_PEER, + always_accept_verify_cb); + /* let us realloc bufs that we're writing from */ + SSL_CTX_set_mode(result->ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER); + + return result; + + error: + tls_log_errors(NULL, LOG_WARN, LD_NET, "creating TLS context"); + if (pkey) + EVP_PKEY_free(pkey); + tor_tls_context_decref(result); + return NULL; +} + +/** Invoked when a TLS state changes: log the change at severity 'debug' */ +void +tor_tls_debug_state_callback(const SSL *ssl, int type, int val) +{ + /* LCOV_EXCL_START since this depends on whether debug is captured or not */ + log_debug(LD_HANDSHAKE, "SSL %p is now in state %s [type=%d,val=%d].", + ssl, SSL_state_string_long(ssl), type, val); + /* LCOV_EXCL_STOP */ +} + +/* Return the name of the negotiated ciphersuite in use on <b>tls</b> */ +const char * +tor_tls_get_ciphersuite_name(tor_tls_t *tls) +{ + return SSL_get_cipher(tls->ssl); +} + +/* Here's the old V2 cipher list we sent from 0.2.1.1-alpha up to + * 0.2.3.17-beta. If a client is using this list, we can't believe the ciphers + * that it claims to support. We'll prune this list to remove the ciphers + * *we* don't recognize. */ +STATIC uint16_t v2_cipher_list[] = { + 0xc00a, /* TLS1_TXT_ECDHE_ECDSA_WITH_AES_256_CBC_SHA */ + 0xc014, /* TLS1_TXT_ECDHE_RSA_WITH_AES_256_CBC_SHA */ + 0x0039, /* TLS1_TXT_DHE_RSA_WITH_AES_256_SHA */ + 0x0038, /* TLS1_TXT_DHE_DSS_WITH_AES_256_SHA */ + 0xc00f, /* TLS1_TXT_ECDH_RSA_WITH_AES_256_CBC_SHA */ + 0xc005, /* TLS1_TXT_ECDH_ECDSA_WITH_AES_256_CBC_SHA */ + 0x0035, /* TLS1_TXT_RSA_WITH_AES_256_SHA */ + 0xc007, /* TLS1_TXT_ECDHE_ECDSA_WITH_RC4_128_SHA */ + 0xc009, /* TLS1_TXT_ECDHE_ECDSA_WITH_AES_128_CBC_SHA */ + 0xc011, /* TLS1_TXT_ECDHE_RSA_WITH_RC4_128_SHA */ + 0xc013, /* TLS1_TXT_ECDHE_RSA_WITH_AES_128_CBC_SHA */ + 0x0033, /* TLS1_TXT_DHE_RSA_WITH_AES_128_SHA */ + 0x0032, /* TLS1_TXT_DHE_DSS_WITH_AES_128_SHA */ + 0xc00c, /* TLS1_TXT_ECDH_RSA_WITH_RC4_128_SHA */ + 0xc00e, /* TLS1_TXT_ECDH_RSA_WITH_AES_128_CBC_SHA */ + 0xc002, /* TLS1_TXT_ECDH_ECDSA_WITH_RC4_128_SHA */ + 0xc004, /* TLS1_TXT_ECDH_ECDSA_WITH_AES_128_CBC_SHA */ + 0x0004, /* SSL3_TXT_RSA_RC4_128_MD5 */ + 0x0005, /* SSL3_TXT_RSA_RC4_128_SHA */ + 0x002f, /* TLS1_TXT_RSA_WITH_AES_128_SHA */ + 0xc008, /* TLS1_TXT_ECDHE_ECDSA_WITH_DES_192_CBC3_SHA */ + 0xc012, /* TLS1_TXT_ECDHE_RSA_WITH_DES_192_CBC3_SHA */ + 0x0016, /* SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA */ + 0x0013, /* SSL3_TXT_EDH_DSS_DES_192_CBC3_SHA */ + 0xc00d, /* TLS1_TXT_ECDH_RSA_WITH_DES_192_CBC3_SHA */ + 0xc003, /* TLS1_TXT_ECDH_ECDSA_WITH_DES_192_CBC3_SHA */ + 0xfeff, /* SSL3_TXT_RSA_FIPS_WITH_3DES_EDE_CBC_SHA */ + 0x000a, /* SSL3_TXT_RSA_DES_192_CBC3_SHA */ + 0 +}; +/** Have we removed the unrecognized ciphers from v2_cipher_list yet? */ +static int v2_cipher_list_pruned = 0; + +/** Return 0 if <b>m</b> does not support the cipher with ID <b>cipher</b>; + * return 1 if it does support it, or if we have no way to tell. */ +int +find_cipher_by_id(const SSL *ssl, const SSL_METHOD *m, uint16_t cipher) +{ + const SSL_CIPHER *c; +#ifdef HAVE_SSL_CIPHER_FIND + (void) m; + { + unsigned char cipherid[3]; + tor_assert(ssl); + set_uint16(cipherid, tor_htons(cipher)); + cipherid[2] = 0; /* If ssl23_get_cipher_by_char finds no cipher starting + * with a two-byte 'cipherid', it may look for a v2 + * cipher with the appropriate 3 bytes. */ + c = SSL_CIPHER_find((SSL*)ssl, cipherid); + if (c) + tor_assert((SSL_CIPHER_get_id(c) & 0xffff) == cipher); + return c != NULL; + } +#else /* !(defined(HAVE_SSL_CIPHER_FIND)) */ + +# if defined(HAVE_STRUCT_SSL_METHOD_ST_GET_CIPHER_BY_CHAR) + if (m && m->get_cipher_by_char) { + unsigned char cipherid[3]; + set_uint16(cipherid, tor_htons(cipher)); + cipherid[2] = 0; /* If ssl23_get_cipher_by_char finds no cipher starting + * with a two-byte 'cipherid', it may look for a v2 + * cipher with the appropriate 3 bytes. */ + c = m->get_cipher_by_char(cipherid); + if (c) + tor_assert((c->id & 0xffff) == cipher); + return c != NULL; + } +#endif /* defined(HAVE_STRUCT_SSL_METHOD_ST_GET_CIPHER_BY_CHAR) */ +# ifndef OPENSSL_1_1_API + if (m && m->get_cipher && m->num_ciphers) { + /* It would seem that some of the "let's-clean-up-openssl" forks have + * removed the get_cipher_by_char function. Okay, so now you get a + * quadratic search. + */ + int i; + for (i = 0; i < m->num_ciphers(); ++i) { + c = m->get_cipher(i); + if (c && (c->id & 0xffff) == cipher) { + return 1; + } + } + return 0; + } +#endif /* !defined(OPENSSL_1_1_API) */ + (void) ssl; + (void) m; + (void) cipher; + return 1; /* No way to search */ +#endif /* defined(HAVE_SSL_CIPHER_FIND) */ +} + +/** Remove from v2_cipher_list every cipher that we don't support, so that + * comparing v2_cipher_list to a client's cipher list will give a sensible + * result. */ +static void +prune_v2_cipher_list(const SSL *ssl) +{ + uint16_t *inp, *outp; +#ifdef HAVE_TLS_METHOD + const SSL_METHOD *m = TLS_method(); +#else + const SSL_METHOD *m = SSLv23_method(); +#endif + + inp = outp = v2_cipher_list; + while (*inp) { + if (find_cipher_by_id(ssl, m, *inp)) { + *outp++ = *inp++; + } else { + inp++; + } + } + *outp = 0; + + v2_cipher_list_pruned = 1; +} + +/** Examine the client cipher list in <b>ssl</b>, and determine what kind of + * client it is. Return one of CIPHERS_ERR, CIPHERS_V1, CIPHERS_V2, + * CIPHERS_UNRESTRICTED. + **/ +int +tor_tls_classify_client_ciphers(const SSL *ssl, + STACK_OF(SSL_CIPHER) *peer_ciphers) +{ + int i, res; + tor_tls_t *tor_tls; + if (PREDICT_UNLIKELY(!v2_cipher_list_pruned)) + prune_v2_cipher_list(ssl); + + tor_tls = tor_tls_get_by_ssl(ssl); + if (tor_tls && tor_tls->client_cipher_list_type) + return tor_tls->client_cipher_list_type; + + /* If we reached this point, we just got a client hello. See if there is + * a cipher list. */ + if (!peer_ciphers) { + log_info(LD_NET, "No ciphers on session"); + res = CIPHERS_ERR; + goto done; + } + /* Now we need to see if there are any ciphers whose presence means we're + * dealing with an updated Tor. */ + for (i = 0; i < sk_SSL_CIPHER_num(peer_ciphers); ++i) { + const SSL_CIPHER *cipher = sk_SSL_CIPHER_value(peer_ciphers, i); + const char *ciphername = SSL_CIPHER_get_name(cipher); + if (strcmp(ciphername, TLS1_TXT_DHE_RSA_WITH_AES_128_SHA) && + strcmp(ciphername, TLS1_TXT_DHE_RSA_WITH_AES_256_SHA) && + strcmp(ciphername, SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA) && + strcmp(ciphername, "(NONE)")) { + log_debug(LD_NET, "Got a non-version-1 cipher called '%s'", ciphername); + // return 1; + goto v2_or_higher; + } + } + res = CIPHERS_V1; + goto done; + v2_or_higher: + { + const uint16_t *v2_cipher = v2_cipher_list; + for (i = 0; i < sk_SSL_CIPHER_num(peer_ciphers); ++i) { + const SSL_CIPHER *cipher = sk_SSL_CIPHER_value(peer_ciphers, i); + uint16_t id = SSL_CIPHER_get_id(cipher) & 0xffff; + if (id == 0x00ff) /* extended renegotiation indicator. */ + continue; + if (!id || id != *v2_cipher) { + res = CIPHERS_UNRESTRICTED; + goto dump_ciphers; + } + ++v2_cipher; + } + if (*v2_cipher != 0) { + res = CIPHERS_UNRESTRICTED; + goto dump_ciphers; + } + res = CIPHERS_V2; + } + + dump_ciphers: + { + smartlist_t *elts = smartlist_new(); + char *s; + for (i = 0; i < sk_SSL_CIPHER_num(peer_ciphers); ++i) { + const SSL_CIPHER *cipher = sk_SSL_CIPHER_value(peer_ciphers, i); + const char *ciphername = SSL_CIPHER_get_name(cipher); + smartlist_add(elts, (char*)ciphername); + } + s = smartlist_join_strings(elts, ":", 0, NULL); + log_debug(LD_NET, "Got a %s V2/V3 cipher list from %s. It is: '%s'", + (res == CIPHERS_V2) ? "fictitious" : "real", ADDR(tor_tls), s); + tor_free(s); + smartlist_free(elts); + } + done: - if (tor_tls) ++ if (tor_tls && peer_ciphers) + return tor_tls->client_cipher_list_type = res; + + return res; +} + +/** Return true iff the cipher list suggested by the client for <b>ssl</b> is + * a list that indicates that the client knows how to do the v2 TLS connection + * handshake. */ +int +tor_tls_client_is_using_v2_ciphers(const SSL *ssl) +{ + STACK_OF(SSL_CIPHER) *ciphers; +#ifdef HAVE_SSL_GET_CLIENT_CIPHERS + ciphers = SSL_get_client_ciphers(ssl); +#else + SSL_SESSION *session; + if (!(session = SSL_get_session((SSL *)ssl))) { + log_info(LD_NET, "No session on TLS?"); + return CIPHERS_ERR; + } + ciphers = session->ciphers; +#endif /* defined(HAVE_SSL_GET_CLIENT_CIPHERS) */ + + return tor_tls_classify_client_ciphers(ssl, ciphers) >= CIPHERS_V2; +} + +/** Invoked when we're accepting a connection on <b>ssl</b>, and the connection + * changes state. We use this: + * <ul><li>To alter the state of the handshake partway through, so we + * do not send or request extra certificates in v2 handshakes.</li> + * <li>To detect renegotiation</li></ul> + */ +void +tor_tls_server_info_callback(const SSL *ssl, int type, int val) +{ + tor_tls_t *tls; + (void) val; + + IF_BUG_ONCE(ssl == NULL) { + return; // LCOV_EXCL_LINE + } + + tor_tls_debug_state_callback(ssl, type, val); + + if (type != SSL_CB_ACCEPT_LOOP) + return; + + OSSL_HANDSHAKE_STATE ssl_state = SSL_get_state(ssl); + if (! STATE_IS_SW_SERVER_HELLO(ssl_state)) + return; + tls = tor_tls_get_by_ssl(ssl); + if (tls) { + /* Check whether we're watching for renegotiates. If so, this is one! */ + if (tls->negotiated_callback) + tls->got_renegotiate = 1; + } else { + log_warn(LD_BUG, "Couldn't look up the tls for an SSL*. How odd!"); + return; + } + + /* Now check the cipher list. */ + if (tor_tls_client_is_using_v2_ciphers(ssl)) { + if (tls->wasV2Handshake) + return; /* We already turned this stuff off for the first handshake; + * This is a renegotiation. */ + + /* Yes, we're casting away the const from ssl. This is very naughty of us. + * Let's hope openssl doesn't notice! */ + + /* Set SSL_MODE_NO_AUTO_CHAIN to keep from sending back any extra certs. */ + SSL_set_mode((SSL*) ssl, SSL_MODE_NO_AUTO_CHAIN); + /* Don't send a hello request. */ + SSL_set_verify((SSL*) ssl, SSL_VERIFY_NONE, NULL); + + if (tls) { + tls->wasV2Handshake = 1; + } else { + /* LCOV_EXCL_START this line is not reachable */ + log_warn(LD_BUG, "Couldn't look up the tls for an SSL*. How odd!"); + /* LCOV_EXCL_STOP */ + } + } +} + +/** Callback to get invoked on a server after we've read the list of ciphers + * the client supports, but before we pick our own ciphersuite. + * + * We can't abuse an info_cb for this, since by the time one of the + * client_hello info_cbs is called, we've already picked which ciphersuite to + * use. + * + * Technically, this function is an abuse of this callback, since the point of + * a session_secret_cb is to try to set up and/or verify a shared-secret for + * authentication on the fly. But as long as we return 0, we won't actually be + * setting up a shared secret, and all will be fine. + */ +int +tor_tls_session_secret_cb(SSL *ssl, void *secret, int *secret_len, + STACK_OF(SSL_CIPHER) *peer_ciphers, + CONST_IF_OPENSSL_1_1_API SSL_CIPHER **cipher, + void *arg) +{ + (void) secret; + (void) secret_len; + (void) peer_ciphers; + (void) cipher; + (void) arg; + + if (tor_tls_classify_client_ciphers(ssl, peer_ciphers) == + CIPHERS_UNRESTRICTED) { + SSL_set_cipher_list(ssl, UNRESTRICTED_SERVER_CIPHER_LIST); + } + + SSL_set_session_secret_cb(ssl, NULL, NULL); + + return 0; +} +static void +tor_tls_setup_session_secret_cb(tor_tls_t *tls) +{ + SSL_set_session_secret_cb(tls->ssl, tor_tls_session_secret_cb, NULL); +} + +/** Create a new TLS object from a file descriptor, and a flag to + * determine whether it is functioning as a server. + */ +tor_tls_t * +tor_tls_new(tor_socket_t sock, int isServer) +{ + BIO *bio = NULL; + tor_tls_t *result = tor_malloc_zero(sizeof(tor_tls_t)); + tor_tls_context_t *context = tor_tls_context_get(isServer); + result->magic = TOR_TLS_MAGIC; + + check_no_tls_errors(); + tor_assert(context); /* make sure somebody made it first */ + if (!(result->ssl = SSL_new(context->ctx))) { + tls_log_errors(NULL, LOG_WARN, LD_NET, "creating SSL object"); + tor_free(result); + goto err; + } + +#ifdef SSL_set_tlsext_host_name + /* Browsers use the TLS hostname extension, so we should too. */ + if (!isServer) { + char *fake_hostname = crypto_random_hostname(4,25, "www.",".com"); + SSL_set_tlsext_host_name(result->ssl, fake_hostname); + tor_free(fake_hostname); + } +#endif /* defined(SSL_set_tlsext_host_name) */ + +#ifdef SSL_CTRL_SET_MAX_PROTO_VERSION + if (openssl_bug_7712_is_present) { + /* We can't actually use TLS 1.3 until this bug is fixed. */ + SSL_set_max_proto_version(result->ssl, TLS1_2_VERSION); + } +#endif + + if (!SSL_set_cipher_list(result->ssl, + isServer ? SERVER_CIPHER_LIST : CLIENT_CIPHER_LIST)) { + tls_log_errors(NULL, LOG_WARN, LD_NET, "setting ciphers"); +#ifdef SSL_set_tlsext_host_name + SSL_set_tlsext_host_name(result->ssl, NULL); +#endif + SSL_free(result->ssl); + tor_free(result); + goto err; + } + result->socket = sock; + bio = BIO_new_socket(sock, BIO_CLOSE); + if (! bio) { + tls_log_errors(NULL, LOG_WARN, LD_NET, "opening BIO"); +#ifdef SSL_set_tlsext_host_name + SSL_set_tlsext_host_name(result->ssl, NULL); +#endif + SSL_free(result->ssl); + tor_free(result); + goto err; + } + { + int set_worked = + SSL_set_ex_data(result->ssl, tor_tls_object_ex_data_index, result); + if (!set_worked) { + log_warn(LD_BUG, + "Couldn't set the tls for an SSL*; connection will fail"); + } + } + SSL_set_bio(result->ssl, bio, bio); + tor_tls_context_incref(context); + result->context = context; + result->state = TOR_TLS_ST_HANDSHAKE; + result->isServer = isServer; + result->wantwrite_n = 0; + result->last_write_count = (unsigned long) BIO_number_written(bio); + result->last_read_count = (unsigned long) BIO_number_read(bio); + if (result->last_write_count || result->last_read_count) { + log_warn(LD_NET, "Newly created BIO has read count %lu, write count %lu", + result->last_read_count, result->last_write_count); + } + if (isServer) { + SSL_set_info_callback(result->ssl, tor_tls_server_info_callback); + } else { + SSL_set_info_callback(result->ssl, tor_tls_debug_state_callback); + } + + if (isServer) + tor_tls_setup_session_secret_cb(result); + + goto done; + err: + result = NULL; + done: + /* Not expected to get called. */ + tls_log_errors(NULL, LOG_WARN, LD_NET, "creating tor_tls_t object"); + return result; +} + +/** Set <b>cb</b> to be called with argument <b>arg</b> whenever <b>tls</b> + * next gets a client-side renegotiate in the middle of a read. Do not + * invoke this function until <em>after</em> initial handshaking is done! + */ +void +tor_tls_set_renegotiate_callback(tor_tls_t *tls, + void (*cb)(tor_tls_t *, void *arg), + void *arg) +{ + tls->negotiated_callback = cb; + tls->callback_arg = arg; + tls->got_renegotiate = 0; + if (cb) { + SSL_set_info_callback(tls->ssl, tor_tls_server_info_callback); + } else { + SSL_set_info_callback(tls->ssl, tor_tls_debug_state_callback); + } +} + +/** If this version of openssl requires it, turn on renegotiation on + * <b>tls</b>. + */ +void +tor_tls_unblock_renegotiation(tor_tls_t *tls) +{ + /* Yes, we know what we are doing here. No, we do not treat a renegotiation + * as authenticating any earlier-received data. */ + SSL_set_options(tls->ssl, + SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION); +} + +/** If this version of openssl supports it, turn off renegotiation on + * <b>tls</b>. (Our protocol never requires this for security, but it's nice + * to use belt-and-suspenders here.) + */ +void +tor_tls_block_renegotiation(tor_tls_t *tls) +{ +#ifdef SUPPORT_UNSAFE_RENEGOTIATION_FLAG + tls->ssl->s3->flags &= ~SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION; +#else + (void) tls; +#endif +} + +/** Assert that the flags that allow legacy renegotiation are still set */ +void +tor_tls_assert_renegotiation_unblocked(tor_tls_t *tls) +{ +#if defined(SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) && \ + SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION != 0 + long options = SSL_get_options(tls->ssl); + tor_assert(0 != (options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)); +#else + (void) tls; +#endif /* defined(SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) && ... */ +} + +/** + * Tell the TLS library that the underlying socket for <b>tls</b> has been + * closed, and the library should not attempt to free that socket itself. + */ +void +tor_tls_release_socket(tor_tls_t *tls) +{ + if (! tls) + return; + + BIO *rbio, *wbio; + rbio = SSL_get_rbio(tls->ssl); + wbio = SSL_get_wbio(tls->ssl); + + if (rbio) { + (void) BIO_set_close(rbio, BIO_NOCLOSE); + } + if (wbio && wbio != rbio) { + (void) BIO_set_close(wbio, BIO_NOCLOSE); + } +} + +void +tor_tls_impl_free_(tor_tls_impl_t *ssl) +{ + if (!ssl) + return; + +#ifdef SSL_set_tlsext_host_name + SSL_set_tlsext_host_name(ssl, NULL); +#endif + SSL_free(ssl); +} + +/** Underlying function for TLS reading. Reads up to <b>len</b> + * characters from <b>tls</b> into <b>cp</b>. On success, returns the + * number of characters read. On failure, returns TOR_TLS_ERROR, + * TOR_TLS_CLOSE, TOR_TLS_WANTREAD, or TOR_TLS_WANTWRITE. + */ +MOCK_IMPL(int, +tor_tls_read,(tor_tls_t *tls, char *cp, size_t len)) +{ + int r, err; + tor_assert(tls); + tor_assert(tls->ssl); + tor_assert(tls->state == TOR_TLS_ST_OPEN); + tor_assert(len<INT_MAX); + r = SSL_read(tls->ssl, cp, (int)len); + if (r > 0) { + if (tls->got_renegotiate) { + /* Renegotiation happened! */ + log_info(LD_NET, "Got a TLS renegotiation from %s", ADDR(tls)); + if (tls->negotiated_callback) + tls->negotiated_callback(tls, tls->callback_arg); + tls->got_renegotiate = 0; + } + return r; + } + err = tor_tls_get_error(tls, r, CATCH_ZERO, "reading", LOG_DEBUG, LD_NET); + if (err == TOR_TLS_ZERORETURN_ || err == TOR_TLS_CLOSE) { + log_debug(LD_NET,"read returned r=%d; TLS is closed",r); + tls->state = TOR_TLS_ST_CLOSED; + return TOR_TLS_CLOSE; + } else { + tor_assert(err != TOR_TLS_DONE); + log_debug(LD_NET,"read returned r=%d, err=%d",r,err); + return err; + } +} + +/** Total number of bytes that we've used TLS to send. Used to track TLS + * overhead. */ +STATIC uint64_t total_bytes_written_over_tls = 0; +/** Total number of bytes that TLS has put on the network for us. Used to + * track TLS overhead. */ +STATIC uint64_t total_bytes_written_by_tls = 0; + +/** Underlying function for TLS writing. Write up to <b>n</b> + * characters from <b>cp</b> onto <b>tls</b>. On success, returns the + * number of characters written. On failure, returns TOR_TLS_ERROR, + * TOR_TLS_WANTREAD, or TOR_TLS_WANTWRITE. + */ +int +tor_tls_write(tor_tls_t *tls, const char *cp, size_t n) +{ + int r, err; + tor_assert(tls); + tor_assert(tls->ssl); + tor_assert(tls->state == TOR_TLS_ST_OPEN); + tor_assert(n < INT_MAX); + if (n == 0) + return 0; + if (tls->wantwrite_n) { + /* if WANTWRITE last time, we must use the _same_ n as before */ + tor_assert(n >= tls->wantwrite_n); + log_debug(LD_NET,"resuming pending-write, (%d to flush, reusing %d)", + (int)n, (int)tls->wantwrite_n); + n = tls->wantwrite_n; + tls->wantwrite_n = 0; + } + r = SSL_write(tls->ssl, cp, (int)n); + err = tor_tls_get_error(tls, r, 0, "writing", LOG_INFO, LD_NET); + if (err == TOR_TLS_DONE) { + total_bytes_written_over_tls += r; + return r; + } + if (err == TOR_TLS_WANTWRITE || err == TOR_TLS_WANTREAD) { + tls->wantwrite_n = n; + } + return err; +} + +/** Perform initial handshake on <b>tls</b>. When finished, returns + * TOR_TLS_DONE. On failure, returns TOR_TLS_ERROR, TOR_TLS_WANTREAD, + * or TOR_TLS_WANTWRITE. + */ +int +tor_tls_handshake(tor_tls_t *tls) +{ + int r; + tor_assert(tls); + tor_assert(tls->ssl); + tor_assert(tls->state == TOR_TLS_ST_HANDSHAKE); + + check_no_tls_errors(); + + OSSL_HANDSHAKE_STATE oldstate = SSL_get_state(tls->ssl); + + if (tls->isServer) { + log_debug(LD_HANDSHAKE, "About to call SSL_accept on %p (%s)", tls, + SSL_state_string_long(tls->ssl)); + r = SSL_accept(tls->ssl); + } else { + log_debug(LD_HANDSHAKE, "About to call SSL_connect on %p (%s)", tls, + SSL_state_string_long(tls->ssl)); + r = SSL_connect(tls->ssl); + } + + OSSL_HANDSHAKE_STATE newstate = SSL_get_state(tls->ssl); + + if (oldstate != newstate) + log_debug(LD_HANDSHAKE, "After call, %p was in state %s", + tls, SSL_state_string_long(tls->ssl)); + /* We need to call this here and not earlier, since OpenSSL has a penchant + * for clearing its flags when you say accept or connect. */ + tor_tls_unblock_renegotiation(tls); + r = tor_tls_get_error(tls,r,0, "handshaking", LOG_INFO, LD_HANDSHAKE); + if (ERR_peek_error() != 0) { + tls_log_errors(tls, tls->isServer ? LOG_INFO : LOG_WARN, LD_HANDSHAKE, + "handshaking"); + return TOR_TLS_ERROR_MISC; + } + if (r == TOR_TLS_DONE) { + tls->state = TOR_TLS_ST_OPEN; + return tor_tls_finish_handshake(tls); + } + return r; +} + +/** Perform the final part of the initial TLS handshake on <b>tls</b>. This + * should be called for the first handshake only: it determines whether the v1 + * or the v2 handshake was used, and adjusts things for the renegotiation + * handshake as appropriate. + * + * tor_tls_handshake() calls this on its own; you only need to call this if + * bufferevent is doing the handshake for you. + */ +int +tor_tls_finish_handshake(tor_tls_t *tls) +{ + int r = TOR_TLS_DONE; + check_no_tls_errors(); + if (tls->isServer) { + SSL_set_info_callback(tls->ssl, NULL); + SSL_set_verify(tls->ssl, SSL_VERIFY_PEER, always_accept_verify_cb); + SSL_clear_mode(tls->ssl, SSL_MODE_NO_AUTO_CHAIN); + if (tor_tls_client_is_using_v2_ciphers(tls->ssl)) { + /* This check is redundant, but back when we did it in the callback, + * we might have not been able to look up the tor_tls_t if the code + * was buggy. Fixing that. */ + if (!tls->wasV2Handshake) { + log_warn(LD_BUG, "For some reason, wasV2Handshake didn't" + " get set. Fixing that."); + } + tls->wasV2Handshake = 1; + log_debug(LD_HANDSHAKE, "Completed V2 TLS handshake with client; waiting" + " for renegotiation."); + } else { + tls->wasV2Handshake = 0; + } + } else { + /* Client-side */ + tls->wasV2Handshake = 1; + /* XXXX this can move, probably? -NM */ + if (SSL_set_cipher_list(tls->ssl, SERVER_CIPHER_LIST) == 0) { + tls_log_errors(NULL, LOG_WARN, LD_HANDSHAKE, "re-setting ciphers"); + r = TOR_TLS_ERROR_MISC; + } + } + tls_log_errors(NULL, LOG_WARN, LD_NET, "finishing the handshake"); + return r; +} + +/** Return true iff this TLS connection is authenticated. + */ +int +tor_tls_peer_has_cert(tor_tls_t *tls) +{ + X509 *cert; + cert = SSL_get_peer_certificate(tls->ssl); + tls_log_errors(tls, LOG_WARN, LD_HANDSHAKE, "getting peer certificate"); + if (!cert) + return 0; + X509_free(cert); + return 1; +} + +/** Return a newly allocated copy of the peer certificate, or NULL if there + * isn't one. */ +MOCK_IMPL(tor_x509_cert_t *, +tor_tls_get_peer_cert,(tor_tls_t *tls)) +{ + X509 *cert; + cert = SSL_get_peer_certificate(tls->ssl); + tls_log_errors(tls, LOG_WARN, LD_HANDSHAKE, "getting peer certificate"); + if (!cert) + return NULL; + return tor_x509_cert_new(cert); +} + +/** Return a newly allocated copy of the cerficate we used on the connection, + * or NULL if somehow we didn't use one. */ +MOCK_IMPL(tor_x509_cert_t *, +tor_tls_get_own_cert,(tor_tls_t *tls)) +{ + X509 *cert = SSL_get_certificate(tls->ssl); + tls_log_errors(tls, LOG_WARN, LD_HANDSHAKE, + "getting own-connection certificate"); + if (!cert) + return NULL; + /* Fun inconsistency: SSL_get_peer_certificate increments the reference + * count, but SSL_get_certificate does not. */ + X509 *duplicate = X509_dup(cert); + if (BUG(duplicate == NULL)) + return NULL; + return tor_x509_cert_new(duplicate); +} + +/** Helper function: try to extract a link certificate and an identity + * certificate from <b>tls</b>, and store them in *<b>cert_out</b> and + * *<b>id_cert_out</b> respectively. Log all messages at level + * <b>severity</b>. + * + * Note that a reference is added both of the returned certificates. */ +MOCK_IMPL(void, +try_to_extract_certs_from_tls,(int severity, tor_tls_t *tls, + X509 **cert_out, X509 **id_cert_out)) +{ + X509 *cert = NULL, *id_cert = NULL; + STACK_OF(X509) *chain = NULL; + int num_in_chain, i; + *cert_out = *id_cert_out = NULL; + if (!(cert = SSL_get_peer_certificate(tls->ssl))) + return; + *cert_out = cert; + if (!(chain = SSL_get_peer_cert_chain(tls->ssl))) + return; + num_in_chain = sk_X509_num(chain); + /* 1 means we're receiving (server-side), and it's just the id_cert. + * 2 means we're connecting (client-side), and it's both the link + * cert and the id_cert. + */ + if (num_in_chain < 1) { + log_fn(severity,LD_PROTOCOL, + "Unexpected number of certificates in chain (%d)", + num_in_chain); + return; + } + for (i=0; i<num_in_chain; ++i) { + id_cert = sk_X509_value(chain, i); + if (X509_cmp(id_cert, cert) != 0) + break; + } + *id_cert_out = id_cert ? X509_dup(id_cert) : NULL; +} + +/** Return the number of bytes available for reading from <b>tls</b>. + */ +int +tor_tls_get_pending_bytes(tor_tls_t *tls) +{ + tor_assert(tls); + return SSL_pending(tls->ssl); +} + +/** If <b>tls</b> requires that the next write be of a particular size, + * return that size. Otherwise, return 0. */ +size_t +tor_tls_get_forced_write_size(tor_tls_t *tls) +{ + return tls->wantwrite_n; +} + +/** Sets n_read and n_written to the number of bytes read and written, + * respectively, on the raw socket used by <b>tls</b> since the last time this + * function was called on <b>tls</b>. */ +void +tor_tls_get_n_raw_bytes(tor_tls_t *tls, size_t *n_read, size_t *n_written) +{ + BIO *wbio, *tmpbio; + unsigned long r, w; + r = (unsigned long) BIO_number_read(SSL_get_rbio(tls->ssl)); + /* We want the number of bytes actually for real written. Unfortunately, + * sometimes OpenSSL replaces the wbio on tls->ssl with a buffering bio, + * which makes the answer turn out wrong. Let's cope with that. Note + * that this approach will fail if we ever replace tls->ssl's BIOs with + * buffering bios for reasons of our own. As an alternative, we could + * save the original BIO for tls->ssl in the tor_tls_t structure, but + * that would be tempting fate. */ + wbio = SSL_get_wbio(tls->ssl); +#if OPENSSL_VERSION_NUMBER >= OPENSSL_VER(1,1,0,0,5) + /* BIO structure is opaque as of OpenSSL 1.1.0-pre5-dev. Again, not + * supposed to use this form of the version macro, but the OpenSSL developers + * introduced major API changes in the pre-release stage. + */ + if (BIO_method_type(wbio) == BIO_TYPE_BUFFER && + (tmpbio = BIO_next(wbio)) != NULL) + wbio = tmpbio; +#else /* !(OPENSSL_VERSION_NUMBER >= OPENSSL_VER(1,1,0,0,5)) */ + if (wbio->method == BIO_f_buffer() && (tmpbio = BIO_next(wbio)) != NULL) + wbio = tmpbio; +#endif /* OPENSSL_VERSION_NUMBER >= OPENSSL_VER(1,1,0,0,5) */ + w = (unsigned long) BIO_number_written(wbio); + + /* We are ok with letting these unsigned ints go "negative" here: + * If we wrapped around, this should still give us the right answer, unless + * we wrapped around by more than ULONG_MAX since the last time we called + * this function. + */ + *n_read = (size_t)(r - tls->last_read_count); + *n_written = (size_t)(w - tls->last_write_count); + if (*n_read > INT_MAX || *n_written > INT_MAX) { + log_warn(LD_BUG, "Preposterously large value in tor_tls_get_n_raw_bytes. " + "r=%lu, last_read=%lu, w=%lu, last_written=%lu", + r, tls->last_read_count, w, tls->last_write_count); + } + total_bytes_written_by_tls += *n_written; + tls->last_read_count = r; + tls->last_write_count = w; +} + +/** Return a ratio of the bytes that TLS has sent to the bytes that we've told + * it to send. Used to track whether our TLS records are getting too tiny. */ +MOCK_IMPL(double, +tls_get_write_overhead_ratio,(void)) +{ + if (total_bytes_written_over_tls == 0) + return 1.0; + + return ((double)total_bytes_written_by_tls) / + ((double)total_bytes_written_over_tls); +} + +/** Implement check_no_tls_errors: If there are any pending OpenSSL + * errors, log an error message. */ +void +check_no_tls_errors_(const char *fname, int line) +{ + if (ERR_peek_error() == 0) + return; + log_warn(LD_CRYPTO, "Unhandled OpenSSL errors found at %s:%d: ", + tor_fix_source_file(fname), line); + tls_log_errors(NULL, LOG_WARN, LD_NET, NULL); +} + +/** Return true iff the initial TLS connection at <b>tls</b> did not use a v2 + * TLS handshake. Output is undefined if the handshake isn't finished. */ +int +tor_tls_used_v1_handshake(tor_tls_t *tls) +{ + return ! tls->wasV2Handshake; +} + +/** Return true iff the server TLS connection <b>tls</b> got the renegotiation + * request it was waiting for. */ +int +tor_tls_server_got_renegotiate(tor_tls_t *tls) +{ + return tls->got_renegotiate; +} + +#ifndef HAVE_SSL_GET_CLIENT_RANDOM +static size_t +SSL_get_client_random(SSL *s, uint8_t *out, size_t len) +{ + if (len == 0) + return SSL3_RANDOM_SIZE; + tor_assert(len == SSL3_RANDOM_SIZE); + tor_assert(s->s3); + memcpy(out, s->s3->client_random, len); + return len; +} +#endif /* !defined(HAVE_SSL_GET_CLIENT_RANDOM) */ + +#ifndef HAVE_SSL_GET_SERVER_RANDOM +static size_t +SSL_get_server_random(SSL *s, uint8_t *out, size_t len) +{ + if (len == 0) + return SSL3_RANDOM_SIZE; + tor_assert(len == SSL3_RANDOM_SIZE); + tor_assert(s->s3); + memcpy(out, s->s3->server_random, len); + return len; +} +#endif /* !defined(HAVE_SSL_GET_SERVER_RANDOM) */ + +#ifndef HAVE_SSL_SESSION_GET_MASTER_KEY +size_t +SSL_SESSION_get_master_key(SSL_SESSION *s, uint8_t *out, size_t len) +{ + tor_assert(s); + if (len == 0) + return s->master_key_length; + tor_assert(len == (size_t)s->master_key_length); + tor_assert(out); + memcpy(out, s->master_key, len); + return len; +} +#endif /* !defined(HAVE_SSL_SESSION_GET_MASTER_KEY) */ + +/** Set the DIGEST256_LEN buffer at <b>secrets_out</b> to the value used in + * the v3 handshake to prove that the client knows the TLS secrets for the + * connection <b>tls</b>. Return 0 on success, -1 on failure. + */ +MOCK_IMPL(int, +tor_tls_get_tlssecrets,(tor_tls_t *tls, uint8_t *secrets_out)) +{ +#define TLSSECRET_MAGIC "Tor V3 handshake TLS cross-certification" + uint8_t buf[128]; + size_t len; + tor_assert(tls); + + SSL *const ssl = tls->ssl; + SSL_SESSION *const session = SSL_get_session(ssl); + + tor_assert(ssl); + tor_assert(session); + + const size_t server_random_len = SSL_get_server_random(ssl, NULL, 0); + const size_t client_random_len = SSL_get_client_random(ssl, NULL, 0); + const size_t master_key_len = SSL_SESSION_get_master_key(session, NULL, 0); + + tor_assert(server_random_len); + tor_assert(client_random_len); + tor_assert(master_key_len); + + len = client_random_len + server_random_len + strlen(TLSSECRET_MAGIC) + 1; + tor_assert(len <= sizeof(buf)); + + { + size_t r = SSL_get_client_random(ssl, buf, client_random_len); + tor_assert(r == client_random_len); + } + + { + size_t r = SSL_get_server_random(ssl, + buf+client_random_len, + server_random_len); + tor_assert(r == server_random_len); + } + + uint8_t *master_key = tor_malloc_zero(master_key_len); + { + size_t r = SSL_SESSION_get_master_key(session, master_key, master_key_len); + tor_assert(r == master_key_len); + } + + uint8_t *nextbuf = buf + client_random_len + server_random_len; + memcpy(nextbuf, TLSSECRET_MAGIC, strlen(TLSSECRET_MAGIC) + 1); + + /* + The value is an HMAC, using the TLS master key as the HMAC key, of + client_random | server_random | TLSSECRET_MAGIC + */ + crypto_hmac_sha256((char*)secrets_out, + (char*)master_key, + master_key_len, + (char*)buf, len); + memwipe(buf, 0, sizeof(buf)); + memwipe(master_key, 0, master_key_len); + tor_free(master_key); + + return 0; +} + +/** Using the RFC5705 key material exporting construction, and the + * provided <b>context</b> (<b>context_len</b> bytes long) and + * <b>label</b> (a NUL-terminated string), compute a 32-byte secret in + * <b>secrets_out</b> that only the parties to this TLS session can + * compute. Return 0 on success; -1 on failure; and -2 on failure + * caused by OpenSSL bug 7712. + */ +MOCK_IMPL(int, +tor_tls_export_key_material,(tor_tls_t *tls, uint8_t *secrets_out, + const uint8_t *context, + size_t context_len, + const char *label)) +{ + tor_assert(tls); + tor_assert(tls->ssl); + + int r = SSL_export_keying_material(tls->ssl, + secrets_out, DIGEST256_LEN, + label, strlen(label), + context, context_len, 1); + + if (r != 1) { + int severity = openssl_bug_7712_is_present ? LOG_WARN : LOG_DEBUG; + tls_log_errors(tls, severity, LD_NET, "exporting keying material"); + } + +#ifdef TLS1_3_VERSION + if (r != 1 && + strlen(label) > 12 && + SSL_version(tls->ssl) >= TLS1_3_VERSION) { + + if (! openssl_bug_7712_is_present) { + /* We might have run into OpenSSL issue 7712, which caused OpenSSL + * 1.1.1a to not handle long labels. Let's test to see if we have. + */ + r = SSL_export_keying_material(tls->ssl, secrets_out, DIGEST256_LEN, + "short", 5, context, context_len, 1); + if (r == 1) { + /* A short label succeeds, but a long label fails. This was openssl + * issue 7712. */ + openssl_bug_7712_is_present = 1; + log_warn(LD_GENERAL, "Detected OpenSSL bug 7712: disabling TLS 1.3 on " + "future connections. A fix is expected to appear in OpenSSL " + "1.1.1b."); + } + } + if (openssl_bug_7712_is_present) + return -2; + else + return -1; + } +#endif + + return (r == 1) ? 0 : -1; +} + +/** Examine the amount of memory used and available for buffers in <b>tls</b>. + * Set *<b>rbuf_capacity</b> to the amount of storage allocated for the read + * buffer and *<b>rbuf_bytes</b> to the amount actually used. + * Set *<b>wbuf_capacity</b> to the amount of storage allocated for the write + * buffer and *<b>wbuf_bytes</b> to the amount actually used. + * + * Return 0 on success, -1 on failure.*/ +int +tor_tls_get_buffer_sizes(tor_tls_t *tls, + size_t *rbuf_capacity, size_t *rbuf_bytes, + size_t *wbuf_capacity, size_t *wbuf_bytes) +{ +#if OPENSSL_VERSION_NUMBER >= OPENSSL_V_SERIES(1,1,0) + (void)tls; + (void)rbuf_capacity; + (void)rbuf_bytes; + (void)wbuf_capacity; + (void)wbuf_bytes; + + return -1; +#else /* !(OPENSSL_VERSION_NUMBER >= OPENSSL_V_SERIES(1,1,0)) */ + if (tls->ssl->s3->rbuf.buf) + *rbuf_capacity = tls->ssl->s3->rbuf.len; + else + *rbuf_capacity = 0; + if (tls->ssl->s3->wbuf.buf) + *wbuf_capacity = tls->ssl->s3->wbuf.len; + else + *wbuf_capacity = 0; + *rbuf_bytes = tls->ssl->s3->rbuf.left; + *wbuf_bytes = tls->ssl->s3->wbuf.left; + return 0; +#endif /* OPENSSL_VERSION_NUMBER >= OPENSSL_V_SERIES(1,1,0) */ +} + +/** Check whether the ECC group requested is supported by the current OpenSSL + * library instance. Return 1 if the group is supported, and 0 if not. + */ +int +evaluate_ecgroup_for_tls(const char *ecgroup) +{ + EC_KEY *ec_key; + int nid; + int ret; + + if (!ecgroup) + nid = NID_tor_default_ecdhe_group; + else if (!strcasecmp(ecgroup, "P256")) + nid = NID_X9_62_prime256v1; + else if (!strcasecmp(ecgroup, "P224")) + nid = NID_secp224r1; + else + return 0; + + ec_key = EC_KEY_new_by_curve_name(nid); + ret = (ec_key != NULL); + EC_KEY_free(ec_key); + + return ret; +}