This removes also the checks in options.c itself as they we now bail out
later and no longer need to ignore them during parsing.
Change-Id: I872c06f402c35112194ba77c3d6aee78e22547cb
Signed-off-by: Arne Schwabe <a...@rfc2549.org>
---
Changes.rst | 4 ++++
src/openvpn/comp.c | 29 +++++++++++++++++++++++++++++
src/openvpn/comp.h | 8 ++++++++
src/openvpn/init.c | 8 ++++++++
src/openvpn/multi.c | 8 ++++++++
src/openvpn/options.c | 27 ++++-----------------------
6 files changed, 61 insertions(+), 23 deletions(-)
diff --git a/Changes.rst b/Changes.rst
index dedb97ee4..77bcef266 100644
--- a/Changes.rst
+++ b/Changes.rst
@@ -232,6 +232,10 @@ User-visible Changes
- The ``client-pending-auth`` management command now requires also the
key id. The management version has been changed to 5 to indicate this change.
+- (OpenVPN 2.6.2) A client will now refuse a connection if pushed compression
+ settings will contradict the setting of allow-compression as this almost
+ always results in a non-working connection.
+
Common errors with OpenSSL 3.0 and OpenVPN 2.6
----------------------------------------------
Both OpenVPN 2.6 and OpenSSL 3.0 tighten the security considerable, so some
diff --git a/src/openvpn/comp.c b/src/openvpn/comp.c
index 3b8d78996..d6d8029da 100644
--- a/src/openvpn/comp.c
+++ b/src/openvpn/comp.c
@@ -157,4 +157,33 @@ comp_generate_peer_info_string(const struct
compress_options *opt, struct buffer
}
}
+bool
+check_compression_settings_valid(struct compress_options *info, int msglevel)
+{
+ if ((info->flags & COMP_F_ALLOW_STUB_ONLY) && comp_non_stub_enabled(info))
+ {
+ msg(msglevel, "Compression is not allowed since allow-compression is "
+ "set to 'no'");
+ return false;
+ }
+#ifndef ENABLE_LZ4
+ if (info->alg == COMP_ALGV2_LZ4 || info->alg == COMP_ALG_LZ4)
+ {
+ msg(msglevel, "OpenVPN is compiled without LZ4 support. Requested "
+ "compression cannot be enabled.");
+ return false;
+ }
+#endif
+#ifndef ENABLE_LZO
+ if (info->alg == COMP_ALG_LZO || info->alg == COMP_ALG_LZ4)
+ {
+ msg(msglevel, "OpenVPN is compiled without LZO support. Requested "
+ "compression cannot be enabled.");
+ return false;
+ }
+#endif
+ return true;
+}
+
+
#endif /* USE_COMP */
diff --git a/src/openvpn/comp.h b/src/openvpn/comp.h
index 685f40391..8636727ab 100644
--- a/src/openvpn/comp.h
+++ b/src/openvpn/comp.h
@@ -196,5 +196,13 @@ comp_non_stub_enabled(const struct compress_options *info)
&& info->alg != COMP_ALG_UNDEF;
}
+/**
+ * Checks if the compression settings are valid. Takes into account the
+ * flags of allow-compression and also the whether algorithms are compiled
+ * in
+ */
+bool
+check_compression_settings_valid(struct compress_options *info, int msglevel);
+
#endif /* USE_COMP */
#endif /* ifndef OPENVPN_COMP_H */
diff --git a/src/openvpn/init.c b/src/openvpn/init.c
index 3a6f624fd..14859499d 100644
--- a/src/openvpn/init.c
+++ b/src/openvpn/init.c
@@ -2637,6 +2637,14 @@ do_deferred_options(struct context *c, const unsigned
int found)
#ifdef USE_COMP
if (found & OPT_P_COMP)
{
+ if (!check_compression_settings_valid(&c->options.comp, D_PUSH_ERRORS))
+ {
+ msg(D_PUSH_ERRORS, "OPTIONS ERROR: server pushed compression "
+ "settings that are not allowed and will result "
+ "in a non-working connection. "
+ "See also allow-compression in the manual.");
+ return false;
+ }
msg(D_PUSH_DEBUG, "OPTIONS IMPORT: compression parms modified");
comp_uninit(c->c2.comp_context);
c->c2.comp_context = comp_init(&c->options.comp);
diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c
index 1480bf477..ac090ef5a 100644
--- a/src/openvpn/multi.c
+++ b/src/openvpn/multi.c
@@ -2766,6 +2766,14 @@ multi_connection_established(struct multi_context *m,
struct multi_instance *mi)
cc_succeeded = false;
}
+#ifdef USE_COMP
+ if (!check_compression_settings_valid(&mi->context.options.comp,
D_MULTI_ERRORS))
+ {
+ msg(D_MULTI_ERRORS, "MULTI: client has been rejected due to invalid
compression options");
+ cc_succeeded = false;
+ }
+#endif
+
if (cc_succeeded)
{
multi_client_connect_late_setup(m, mi, *option_types_found);
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index 2bed4ce99..435e1ca9e 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -3779,6 +3779,9 @@ options_postprocess_mutate(struct options *o, struct
env_set *es)
/* this depends on o->windows_driver, which is set above */
options_postprocess_mutate_invariant(o);
+ /* check that compression settings in the options are okay */
+ check_compression_settings_valid(&o->comp, M_USAGE);
+
/*
* Save certain parms before modifying options during connect, especially
* when using --pull
@@ -8405,21 +8408,12 @@ add_option(struct options *options,
/* All lzo variants do not use swap */
options->comp.flags &= ~COMP_F_SWAP;
-#if defined(ENABLE_LZO)
+
if (p[1] && streq(p[1], "no"))
-#endif
{
options->comp.alg = COMP_ALG_STUB;
options->comp.flags &= ~COMP_F_ADAPTIVE;
}
-#if defined(ENABLE_LZO)
- else if (options->comp.flags & COMP_F_ALLOW_STUB_ONLY)
- {
- /* Also printed on a push to hint at configuration problems */
- msg(msglevel, "Cannot set comp-lzo to '%s', "
- "allow-compression is set to 'no'", p[1]);
- goto err;
- }
else if (p[1])
{
if (streq(p[1], "yes"))
@@ -8444,7 +8438,6 @@ add_option(struct options *options,
options->comp.flags |= COMP_F_ADAPTIVE;
}
show_compression_warning(&options->comp);
-#endif /* if defined(ENABLE_LZO) */
}
else if (streq(p[0], "comp-noadapt") && !p[1])
{
@@ -8478,23 +8471,12 @@ add_option(struct options *options,
{
options->comp.alg = COMP_ALG_UNDEF;
options->comp.flags = COMP_F_MIGRATE;
-
}
- else if (options->comp.flags & COMP_F_ALLOW_STUB_ONLY)
- {
- /* Also printed on a push to hint at configuration problems */
- msg(msglevel, "Cannot set compress to '%s', "
- "allow-compression is set to 'no'", alg);
- goto err;
- }
-#if defined(ENABLE_LZO)
else if (streq(alg, "lzo"))
{
options->comp.alg = COMP_ALG_LZO;
options->comp.flags &= ~(COMP_F_ADAPTIVE | COMP_F_SWAP);
}
-#endif
-#if defined(ENABLE_LZ4)
else if (streq(alg, "lz4"))
{
options->comp.alg = COMP_ALG_LZ4;
@@ -8504,7 +8486,6 @@ add_option(struct options *options,
{
options->comp.alg = COMP_ALGV2_LZ4;
}
-#endif
else
{
msg(msglevel, "bad comp option: %s", alg);
--
2.37.1 (Apple Git-137.1)
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