From: Lukas Tribus <lukas@ltri.eu>
Date: Mon, 8 Jul 2019 12:29:15 +0000 (+0200)
Subject: BUG/MINOR: ssl: revert empty handshake detection in OpenSSL <= 1.0.2
X-Git-Tag: v2.1-dev1~22
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=497991613469b588b969f94aea2228720a1bddab;p=thirdparty%2Fhaproxy.git

BUG/MINOR: ssl: revert empty handshake detection in OpenSSL <= 1.0.2

Commit 54832b97 ("BUILD: enable several LibreSSL hacks, including")
changed empty handshake detection in OpenSSL <= 1.0.2 and LibreSSL,
from accessing packet_length directly (not available in LibreSSL) to
calling SSL_state() instead.

However, SSL_state() appears to be fully broken in both OpenSSL and
LibreSSL.

Since there is no possibility in LibreSSL to detect an empty handshake,
let's not try (like BoringSSL) and restore this functionality for
OpenSSL 1.0.2 and older, by reverting to the previous behavior.

Should be backported to 2.0.
---

diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index c9fffbec6c..3ddacb6b58 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -5352,15 +5352,18 @@ static int ssl_sock_handshake(struct connection *conn, unsigned int flag)
 				if (!errno && conn->flags & CO_FL_WAIT_L4_CONN)
 					conn->flags &= ~CO_FL_WAIT_L4_CONN;
 				if (!conn->err_code) {
-#ifdef OPENSSL_IS_BORINGSSL /* BoringSSL */
+#if defined(OPENSSL_IS_BORINGSSL) || defined(LIBRESSL_VERSION_NUMBER)
+					/* do not handle empty handshakes in BoringSSL or LibreSSL */
 					conn->err_code = CO_ER_SSL_HANDSHAKE;
 #else
 					int empty_handshake;
 #if (HA_OPENSSL_VERSION_NUMBER >= 0x1010000fL)
+					/* use SSL_get_state() in OpenSSL >= 1.1.0; SSL_state() is broken */
 					OSSL_HANDSHAKE_STATE state = SSL_get_state((SSL *)ctx->ssl);
 					empty_handshake = state == TLS_ST_BEFORE;
 #else
-					empty_handshake = SSL_state((SSL *)ctx->ssl) == SSL_ST_BEFORE;
+					/* access packet_length directly in OpenSSL <= 1.0.2; SSL_state() is broken */
+					empty_handshake = !ctx->ssl->packet_length;
 #endif
 					if (empty_handshake) {
 						if (!errno) {
@@ -5382,7 +5385,7 @@ static int ssl_sock_handshake(struct connection *conn, unsigned int flag)
 						else
 							conn->err_code = CO_ER_SSL_HANDSHAKE;
 					}
-#endif
+#endif /* BoringSSL or LibreSSL */
 				}
 				goto out_error;
 			}
@@ -5433,15 +5436,18 @@ check_error:
 			if (!errno && conn->flags & CO_FL_WAIT_L4_CONN)
 				conn->flags &= ~CO_FL_WAIT_L4_CONN;
 			if (!conn->err_code) {
-#ifdef OPENSSL_IS_BORINGSSL  /* BoringSSL */
+#if defined(OPENSSL_IS_BORINGSSL) || defined(LIBRESSL_VERSION_NUMBER)
+				/* do not handle empty handshakes in BoringSSL or LibreSSL */
 				conn->err_code = CO_ER_SSL_HANDSHAKE;
 #else
 				int empty_handshake;
 #if (HA_OPENSSL_VERSION_NUMBER >= 0x1010000fL)
+				/* use SSL_get_state() in OpenSSL >= 1.1.0; SSL_state() is broken */
 				OSSL_HANDSHAKE_STATE state = SSL_get_state(ctx->ssl);
 				empty_handshake = state == TLS_ST_BEFORE;
 #else
-				empty_handshake = SSL_state((SSL *)ctx->ssl) == SSL_ST_BEFORE;
+				/* access packet_length directly in OpenSSL <= 1.0.2; SSL_state() is broken */
+				empty_handshake = !ctx->ssl->packet_length;
 #endif
 				if (empty_handshake) {
 					if (!errno) {
@@ -5463,7 +5469,7 @@ check_error:
 					else
 						conn->err_code = CO_ER_SSL_HANDSHAKE;
 				}
-#endif
+#endif /* BoringSSL or LibreSSL */
 			}
 			goto out_error;
 		}