diff options
Diffstat (limited to 'src/common/tortls.c')
| -rw-r--r-- | src/common/tortls.c | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/src/common/tortls.c b/src/common/tortls.c index 352c3d617..ef61f71b3 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -68,6 +68,16 @@ #define ADDR(tls) (((tls) && (tls)->address) ? tls->address : "peer") +#if (OPENSSL_VERSION_NUMBER < 0x0090813fL || \ + (OPENSSL_VERSION_NUMBER >= 0x00909000L && \ + OPENSSL_VERSION_NUMBER < 0x1000006fL)) +/* This is a version of OpenSSL before 0.9.8s/1.0.0f. It does not have + * the CVE-2011-4657 fix, and as such it can't use RELEASE_BUFFERS and + * SSL3 safely at the same time. + */ +#define DISABLE_SSL3_HANDSHAKE +#endif + /* 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.) @@ -766,16 +776,37 @@ tor_tls_context_new(crypto_pk_env_t *identity, unsigned int key_lifetime, result->key = crypto_pk_dup_key(rsa); } -#ifdef EVERYONE_HAS_AES - /* Tell OpenSSL to only use TLS1 */ +#if 0 + /* Tell OpenSSL to only use TLS1. This would actually break compatibility + * with clients that are configured to use SSLv23_method(), so we should + * probably never use it. + */ if (!(result->ctx = SSL_CTX_new(TLSv1_method()))) goto error; -#else +#endif + /* Tell OpenSSL to use SSL3 or TLS1 but not SSL2. */ if (!(result->ctx = SSL_CTX_new(SSLv23_method()))) goto error; SSL_CTX_set_options(result->ctx, SSL_OP_NO_SSLv2); + + if ( +#ifdef DISABLE_SSL3_HANDSHAKE + 1 || #endif + SSLeay() < 0x0090813fL || + (SSLeay() >= 0x00909000L && + SSLeay() < 0x1000006fL)) { + /* And not SSL3 if it's subject to CVE-2011-4657. */ + log_info(LD_NET, "Disabling SSLv3 because this OpenSSL version " + "might otherwise be vulnerable to CVE-2011-4657 " + "(compile-time version %08lx (%s); " + "runtime version %08lx (%s))", + OPENSSL_VERSION_NUMBER, OPENSSL_VERSION_TEXT, + SSLeay(), SSLeay_version(SSLEAY_VERSION)); + SSL_CTX_set_options(result->ctx, SSL_OP_NO_SSLv3); + } + SSL_CTX_set_options(result->ctx, SSL_OP_SINGLE_DH_USE); #ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION |