From 7aa496a2e057bb7c3cc284a04a1a4d2941c304f1 Mon Sep 17 00:00:00 2001 From: Alexander Færøy Date: Thu, 2 Nov 2023 14:38:43 -0400 Subject: Fix TROVE-2023-004: Remote crash when compiled against OpenSSL Fixes #40874 Signed-off-by: David Goulet --- changes/ticket40874 | 3 +++ src/feature/relay/relay_handshake.c | 1 + src/lib/tls/tortls_openssl.c | 32 +++++++++++++++++++++++++++++--- 3 files changed, 33 insertions(+), 3 deletions(-) create mode 100644 changes/ticket40874 diff --git a/changes/ticket40874 b/changes/ticket40874 new file mode 100644 index 0000000000..e1091f6b63 --- /dev/null +++ b/changes/ticket40874 @@ -0,0 +1,3 @@ + o Major bugfixes (TROVE-2023-004, relay): + - Mitigate an issue when Tor compiled with OpenSSL can crash during + handshake with a remote relay. Fixes bug 40874; bugfix on 0.2.7.2-alpha. diff --git a/src/feature/relay/relay_handshake.c b/src/feature/relay/relay_handshake.c index be7dba721a..75546cdd90 100644 --- a/src/feature/relay/relay_handshake.c +++ b/src/feature/relay/relay_handshake.c @@ -414,6 +414,7 @@ connection_or_compute_authenticate_cell_body(or_connection_t *conn, log_fn(LOG_PROTOCOL_WARN, LD_OR, "Somebody asked us for an older TLS " "authentication method (AUTHTYPE_RSA_SHA256_TLSSECRET) " "which we don't support."); + goto err; } } else { char label[128]; diff --git a/src/lib/tls/tortls_openssl.c b/src/lib/tls/tortls_openssl.c index 77de2d6a11..f3257d5f24 100644 --- a/src/lib/tls/tortls_openssl.c +++ b/src/lib/tls/tortls_openssl.c @@ -1649,9 +1649,35 @@ tor_tls_get_tlssecrets,(tor_tls_t *tls, uint8_t *secrets_out)) 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); + if (BUG(! server_random_len)) { + log_warn(LD_NET, "Missing server randomness after handshake " + "using %s (cipher: %s, server: %s) from %s", + SSL_get_version(ssl), + SSL_get_cipher_name(ssl), + tls->isServer ? "true" : "false", + ADDR(tls)); + return -1; + } + + if (BUG(! client_random_len)) { + log_warn(LD_NET, "Missing client randomness after handshake " + "using %s (cipher: %s, server: %s) from %s", + SSL_get_version(ssl), + SSL_get_cipher_name(ssl), + tls->isServer ? "true" : "false", + ADDR(tls)); + return -1; + } + + if (BUG(! master_key_len)) { + log_warn(LD_NET, "Missing master key after handshake " + "using %s (cipher: %s, server: %s) from %s", + SSL_get_version(ssl), + SSL_get_cipher_name(ssl), + tls->isServer ? "true" : "false", + ADDR(tls)); + return -1; + } len = client_random_len + server_random_len + strlen(TLSSECRET_MAGIC) + 1; tor_assert(len <= sizeof(buf)); -- cgit v1.2.3-54-g00ecf