From 51be733ba236610dff6a1c361cf59172db97473a Mon Sep 17 00:00:00 2001 From: Selva Nair Date: Fri, 15 Oct 2021 00:32:27 -0400 Subject: [PATCH] Fix the "default" tls-version-min setting commit 968569f83b1561ea4dff5b8b1f0d7768e2a18e69 defined TLS 1.2 as the minimum version if not set by user. But the patch introduced two errors: (i) ssl_flags is overwritten without regard to other options set in the flags (ii) Any tls-version-max set by the user is not taken into account. Makes it impossible to set tls-version-max without also setting tls-version-min along with loss of other bits set in ssl_flags. Fix it. The fix retains the original intent when possible, and tries to use the maximum possible value when it cannot be set to TLS 1.2 without conflicting with user-specified tls-version-max, if any. Signed-off-by: Selva Nair Acked-by: Arne Schwabe Message-Id: <20211015043227.10679-1-selva.nair@gmail.com> URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22939.html Signed-off-by: Gert Doering --- src/openvpn/options.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/src/openvpn/options.c b/src/openvpn/options.c index b3a83aa1..ed2dcd53 100644 --- a/src/openvpn/options.c +++ b/src/openvpn/options.c @@ -3167,15 +3167,22 @@ options_set_backwards_compatible_options(struct options *o) /* TLS min version is not set */ if ((o->ssl_flags & SSLF_TLS_VERSION_MIN_MASK) == 0) { + int tls_ver_max = (o->ssl_flags >> SSLF_TLS_VERSION_MAX_SHIFT) + & SSLF_TLS_VERSION_MAX_MASK; if (need_compatibility_before(o, 20307)) { /* 2.3.6 and earlier have TLS 1.0 only, set minimum to TLS 1.0 */ - o->ssl_flags = (TLS_VER_1_0 << SSLF_TLS_VERSION_MIN_SHIFT); + o->ssl_flags |= (TLS_VER_1_0 << SSLF_TLS_VERSION_MIN_SHIFT); } - else + else if (tls_ver_max == 0 || tls_ver_max >= TLS_VER_1_2) { /* Use TLS 1.2 as proper default */ - o->ssl_flags = (TLS_VER_1_2 << SSLF_TLS_VERSION_MIN_SHIFT); + o->ssl_flags |= (TLS_VER_1_2 << SSLF_TLS_VERSION_MIN_SHIFT); + } + else + { + /* Maximize the minimum version */ + o->ssl_flags |= (tls_ver_max << SSLF_TLS_VERSION_MIN_SHIFT); } }