[Openvpn-devel] [S] Change in openvpn[master]: Make it more explicit and visible when pkg-config is not found

2024-01-04 Thread ordex (Code Review) 
Attention is currently required from: flichtenheld, plaisthos.

ordex has posted comments on this change. ( 
http://gerrit.openvpn.net/c/openvpn/+/465?usp=email )

Change subject: Make it more explicit and visible when pkg-config is not found
..


Patch Set 3: Code-Review-1

(3 comments)

Patchset:

PS3:
Other than the two comments I added in the code, the patch does what it says 
and it makes very straightforward understanding that pkg-config is now not 
installed.
Tested a couple of cases on my lovely gentoo and it just worked.


File configure.ac:

http://gerrit.openvpn.net/c/openvpn/+/465/comment/a58bb3dc_c4b892a1 :
PS3, Line 385:  pkg_config_found="(not found)"
am I wrong or there is some indentation havoc here? The line above uses 8blanks 
tab, but the lines before have 4 spaces indentation?

I think we uses tabs everywhere else.


http://gerrit.openvpn.net/c/openvpn/+/465/comment/5512845f_c09de864 :
PS3, Line 387:  pkg_config_found="(using ${PKG_CONFIG})"
many error messages already contain 'using pkg-config', therefore the text 
above will lead to 'using using', which sounds weird.
How about changing 'using' with 'path:'?



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Gerrit-Branch: master
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Gerrit-Change-Number: 465
Gerrit-PatchSet: 3
Gerrit-Owner: plaisthos 
Gerrit-Reviewer: cron2 
Gerrit-Reviewer: flichtenheld 
Gerrit-Reviewer: ordex 
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[Openvpn-devel] [PATCH v3] Make it more explicit and visible when pkg-config is not found

2024-01-04 Thread Gert Doering 
From: Arne Schwabe 

Users seem to struggle to read the full error message. This adds an
indication if pkg-config is actually found to the warning/error message
that use pkg-config.

On platforms that do not require pkg-config and for optional libraries,
the existence of pkg-config is mentioned as part of the error/warning message.

When found:

configure: error: libnl-genl-3.0 package not found or too old. Is the 
development package and pkg-config (using /usr/bin/pkg-config) installed? Must 
be version 3.4.0 or newer for DCO

not found:

configure: error: libnl-genl-3.0 package not found or too old. Is the 
development package and pkg-config (not found) installed? Must be version 3.4.0 
or newer for DCO

On platforms where pkg-config is required (only Linux at the moment),
configure will abort when not detecting pkg-config:

checking for pkg-config... no
configure: error: pkg-config is required

Change-Id: Iebaa35a23e217a4cd7739af229cbfc08a3d8854a
Signed-off-by: Arne Schwabe 
Acked-by: Gert Doering 
---

This change was reviewed on Gerrit and approved by at least one
developer. I request to merge it to master.

Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/465
This mail reflects revision 3 of this Change.
Acked-by according to Gerrit (reflected above):
Gert Doering 


diff --git a/configure.ac b/configure.ac
index f420612..f009fe2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -323,6 +323,7 @@
AM_CONDITIONAL([TARGET_LINUX], [true])
AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["L"], [Target prefix])
have_sitnl="yes"
+   pkg_config_required="yes"
;;
*-*-solaris*)
AC_DEFINE([TARGET_SOLARIS], [1], [Are we running on Solaris?])
@@ -376,6 +377,16 @@
 AM_CONDITIONAL([CROSS_COMPILING], test "${cross_compiling}" = "yes")
 
 PKG_PROG_PKG_CONFIG
+# Add variable to print if pkg-config is found or not. Users often miss that
+if test "${PKG_CONFIG}" = ""; then
+if test "${pkg_config_required}" = "yes"; then
+AC_MSG_ERROR([pkg-config is required])
+fi
+   pkg_config_found="(not found)"
+else
+   pkg_config_found="(using ${PKG_CONFIG})"
+fi
+
 AC_PROG_CPP
 AC_PROG_INSTALL
 AC_PROG_LN_S
@@ -810,7 +821,7 @@
  [libnl-genl-3.0 >= 3.4.0],
  [have_libnl="yes"],
  [
-  AC_MSG_ERROR([libnl-genl-3.0 package 
not found or too old. Is the development package and pkg-config installed? Must 
be version 3.4.0 or newer for DCO])
+  AC_MSG_ERROR([libnl-genl-3.0 package 
not found or too old. Is the development package and pkg-config 
${pkg_config_found} installed? Must be version 3.4.0 or newer for DCO])
  ]
)
CFLAGS="${CFLAGS} ${LIBNL_GENL_CFLAGS}"
@@ -854,10 +865,11 @@
 dnl
 case "$host" in
*-*-linux*)
+   # We require pkg-config
PKG_CHECK_MODULES([LIBCAPNG],
  [libcap-ng],
  [],
- [AC_MSG_ERROR([libcap-ng package not found. 
Is the development package and pkg-config installed?])]
+ [AC_MSG_ERROR([libcap-ng package not found. 
Is the development package and pkg-config ${pkg_config_found} installed?])]
)
AC_CHECK_HEADER([sys/prctl.h],,[AC_MSG_ERROR([sys/prctl.h not 
found!])])
 
@@ -878,7 +890,7 @@
[OPENSSL],
[openssl >= 1.0.2],
[have_openssl="yes"],
-   [] # If this fails, we will do another test next
+   [AC_MSG_WARN([OpenSSL not found by pkg-config 
${pkg_config_found}])] # If this fails, we will do another test next
)
OPENSSL_LIBS=${OPENSSL_LIBS:--lssl -lcrypto}
fi
@@ -1083,7 +1095,7 @@
[WOLFSSL],
[wolfssl],
[],
-   [AC_MSG_ERROR([Could not find wolfSSL.])]
+   [AC_MSG_ERROR([Could not find wolfSSL using pkg-config 
${pkg_config_found}])]
)
PKG_CHECK_VAR(
[WOLFSSL_INCLUDEDIR],
@@ -1508,7 +1520,7 @@
 PKG_CHECK_MODULES(
[CMOCKA], [cmocka],
[have_cmocka="yes"],
-   [AC_MSG_WARN([cmocka.pc not found on the system.  Unit tests disabled])]
+   [AC_MSG_WARN([cmocka.pc not found on the system using pkg-config 
${pkg_config_found}.  Unit tests disabled])]
 )
 AM_CONDITIONAL([ENABLE_UNITTESTS], [test "${enable_unit_tests}" = "yes" -a 
"${have_cmocka}" = "yes" ])
 AC_SUBST([ENABLE_UNITTESTS])


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[Openvpn-devel] [S] Change in openvpn[master]: Make it more explicit and visible when pkg-config is not found

2024-01-04 Thread cron2 (Code Review) 
Attention is currently required from: flichtenheld, plaisthos.

cron2 has posted comments on this change. ( 
http://gerrit.openvpn.net/c/openvpn/+/465?usp=email )

Change subject: Make it more explicit and visible when pkg-config is not found
..


Patch Set 3: Code-Review+2

(1 comment)

Patchset:

PS3:
I do like the new approach.  Hope to see a test report from ordex (he does this 
"linux" stuff, I have been told).  But I can still +2 it in the meantime and 
send to the list.



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[Openvpn-devel] [M] Change in openvpn[master]: Check PRF availability on initialisation and add --force-tls-key-mate...

2024-01-04 Thread cron2 (Code Review) 
cron2 has uploaded a new patch set (#10) to the change originally created by 
plaisthos. ( http://gerrit.openvpn.net/c/openvpn/+/460?usp=email )

The following approvals got outdated and were removed:
Code-Review+2 by cron2


Change subject: Check PRF availability on initialisation and add 
--force-tls-key-material-export
..

Check PRF availability on initialisation and add --force-tls-key-material-export

We now warn a user if the TLS 1.0 PRF is not supported by the cryptographic
library of the system. Also add the option --force-tls-key-material-export
that automatically rejects clients that do not support TLS Keying Material
Export and automatically enable it when TLS 1.0 PRF support is not available.

Change-Id: I04f8c7c413e7cb62c726262feee6ca89c7e86c70
Signed-off-by: Arne Schwabe 
Acked-by: Gert Doering 
Message-Id: <20240104140214.32196-1-g...@greenie.muc.de>
URL: 
https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27924.html
Signed-off-by: Gert Doering 
---
M doc/man-sections/protocol-options.rst
M src/openvpn/crypto.c
M src/openvpn/crypto.h
M src/openvpn/multi.c
M src/openvpn/options.c
M src/openvpn/options.h
6 files changed, 84 insertions(+), 0 deletions(-)


  git pull ssh://gerrit.openvpn.net:29418/openvpn refs/changes/60/460/10

diff --git a/doc/man-sections/protocol-options.rst 
b/doc/man-sections/protocol-options.rst
index 948c0c8..8b061d2 100644
--- a/doc/man-sections/protocol-options.rst
+++ b/doc/man-sections/protocol-options.rst
@@ -242,3 +242,11 @@
   a key renegotiation begins (default :code:`3600` seconds). This feature
   allows for a graceful transition from old to new key, and removes the key
   renegotiation sequence from the critical path of tunnel data forwarding.
+
+--force-tls-key-material-export
+  This option is only available in --mode server and forces to use
+  Keying Material Exporters (RFC 5705) for clients. This can be used to
+  simulate an environment where the cryptographic library does not support
+  the older method to generate data channel keys anymore. This option is
+  intended to be a test option and might be removed in a future OpenVPN
+  version without notice.
diff --git a/src/openvpn/crypto.c b/src/openvpn/crypto.c
index e4452d7..2fca131 100644
--- a/src/openvpn/crypto.c
+++ b/src/openvpn/crypto.c
@@ -27,6 +27,7 @@
 #endif

 #include "syshead.h"
+#include 

 #include "crypto.h"
 #include "error.h"
@@ -1789,3 +1790,22 @@
 gc_free(&gc);
 return ret;
 }
+
+bool
+check_tls_prf_working(void)
+{
+/* Modern TLS libraries might no longer support the TLS 1.0 PRF with
+ * MD5+SHA1. This allows us to establish connections only
+ * with other 2.6.0+ OpenVPN peers.
+ * Do a simple dummy test here to see if it works. */
+const char *seed = "tls1-prf-test";
+const char *secret = "tls1-prf-test-secret";
+uint8_t out[8];
+uint8_t expected_out[] = { 'q', 'D', '\xfe', '%', '@', 's', 'u', '\x95' };
+
+int ret = ssl_tls1_PRF((uint8_t *)seed, (int) strlen(seed),
+   (uint8_t *)secret, (int) strlen(secret),
+   out, sizeof(out));
+
+return (ret && memcmp(out, expected_out, sizeof(out)) == 0);
+}
diff --git a/src/openvpn/crypto.h b/src/openvpn/crypto.h
index 9255d38..4201524 100644
--- a/src/openvpn/crypto.h
+++ b/src/openvpn/crypto.h
@@ -593,4 +593,12 @@
 return kt;
 }

+/**
+ * Checks if the current TLS library supports the TLS 1.0 PRF with MD5+SHA1
+ * that OpenVPN uses when TLS Keying Material Export is not available.
+ *
+ * @return  true if supported, false otherwise.
+ */
+bool check_tls_prf_working(void);
+
 #endif /* CRYPTO_H */
diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c
index 8b490ed..f4f0b8a 100644
--- a/src/openvpn/multi.c
+++ b/src/openvpn/multi.c
@@ -1830,6 +1830,16 @@
 {
 o->imported_protocol_flags |= CO_USE_TLS_KEY_MATERIAL_EXPORT;
 }
+else if (o->force_key_material_export)
+{
+msg(M_INFO, "PUSH: client does not support TLS Keying Material "
+"Exporters but --force-tls-key-material-export is enabled.");
+auth_set_client_reason(tls_multi, "Client incompatible with this "
+   "server. Keying Material Exporters (RFC 5705) "
+   "support missing. Upgrade to a client that "
+   "supports this feature (OpenVPN 2.6.0+).");
+return false;
+}
 if (proto & IV_PROTO_DYN_TLS_CRYPT)
 {
 o->imported_protocol_flags |= CO_USE_DYNAMIC_TLS_CRYPT;
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index e498114..1b28a19 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -1561,6 +1561,7 @@
 SHOW_STR(auth_user_pass_verify_script);
 SHOW_BOOL(auth_user_pass_verify_script_via_file);
 SHOW_BOOL(auth_token_generate);
+SHOW_BOOL(force_key_material_export);
 SHOW_INT(auth_token_lifetime);
 S

[Openvpn-devel] [M] Change in openvpn[master]: Check PRF availability on initialisation and add --force-tls-key-mate...

2024-01-04 Thread cron2 (Code Review) 
cron2 has submitted this change. ( 
http://gerrit.openvpn.net/c/openvpn/+/460?usp=email )

Change subject: Check PRF availability on initialisation and add 
--force-tls-key-material-export
..

Check PRF availability on initialisation and add --force-tls-key-material-export

We now warn a user if the TLS 1.0 PRF is not supported by the cryptographic
library of the system. Also add the option --force-tls-key-material-export
that automatically rejects clients that do not support TLS Keying Material
Export and automatically enable it when TLS 1.0 PRF support is not available.

Change-Id: I04f8c7c413e7cb62c726262feee6ca89c7e86c70
Signed-off-by: Arne Schwabe 
Acked-by: Gert Doering 
Message-Id: <20240104140214.32196-1-g...@greenie.muc.de>
URL: 
https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27924.html
Signed-off-by: Gert Doering 
---
M doc/man-sections/protocol-options.rst
M src/openvpn/crypto.c
M src/openvpn/crypto.h
M src/openvpn/multi.c
M src/openvpn/options.c
M src/openvpn/options.h
6 files changed, 84 insertions(+), 0 deletions(-)




diff --git a/doc/man-sections/protocol-options.rst 
b/doc/man-sections/protocol-options.rst
index 948c0c8..8b061d2 100644
--- a/doc/man-sections/protocol-options.rst
+++ b/doc/man-sections/protocol-options.rst
@@ -242,3 +242,11 @@
   a key renegotiation begins (default :code:`3600` seconds). This feature
   allows for a graceful transition from old to new key, and removes the key
   renegotiation sequence from the critical path of tunnel data forwarding.
+
+--force-tls-key-material-export
+  This option is only available in --mode server and forces to use
+  Keying Material Exporters (RFC 5705) for clients. This can be used to
+  simulate an environment where the cryptographic library does not support
+  the older method to generate data channel keys anymore. This option is
+  intended to be a test option and might be removed in a future OpenVPN
+  version without notice.
diff --git a/src/openvpn/crypto.c b/src/openvpn/crypto.c
index e4452d7..2fca131 100644
--- a/src/openvpn/crypto.c
+++ b/src/openvpn/crypto.c
@@ -27,6 +27,7 @@
 #endif

 #include "syshead.h"
+#include 

 #include "crypto.h"
 #include "error.h"
@@ -1789,3 +1790,22 @@
 gc_free(&gc);
 return ret;
 }
+
+bool
+check_tls_prf_working(void)
+{
+/* Modern TLS libraries might no longer support the TLS 1.0 PRF with
+ * MD5+SHA1. This allows us to establish connections only
+ * with other 2.6.0+ OpenVPN peers.
+ * Do a simple dummy test here to see if it works. */
+const char *seed = "tls1-prf-test";
+const char *secret = "tls1-prf-test-secret";
+uint8_t out[8];
+uint8_t expected_out[] = { 'q', 'D', '\xfe', '%', '@', 's', 'u', '\x95' };
+
+int ret = ssl_tls1_PRF((uint8_t *)seed, (int) strlen(seed),
+   (uint8_t *)secret, (int) strlen(secret),
+   out, sizeof(out));
+
+return (ret && memcmp(out, expected_out, sizeof(out)) == 0);
+}
diff --git a/src/openvpn/crypto.h b/src/openvpn/crypto.h
index 9255d38..4201524 100644
--- a/src/openvpn/crypto.h
+++ b/src/openvpn/crypto.h
@@ -593,4 +593,12 @@
 return kt;
 }

+/**
+ * Checks if the current TLS library supports the TLS 1.0 PRF with MD5+SHA1
+ * that OpenVPN uses when TLS Keying Material Export is not available.
+ *
+ * @return  true if supported, false otherwise.
+ */
+bool check_tls_prf_working(void);
+
 #endif /* CRYPTO_H */
diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c
index 8b490ed..f4f0b8a 100644
--- a/src/openvpn/multi.c
+++ b/src/openvpn/multi.c
@@ -1830,6 +1830,16 @@
 {
 o->imported_protocol_flags |= CO_USE_TLS_KEY_MATERIAL_EXPORT;
 }
+else if (o->force_key_material_export)
+{
+msg(M_INFO, "PUSH: client does not support TLS Keying Material "
+"Exporters but --force-tls-key-material-export is enabled.");
+auth_set_client_reason(tls_multi, "Client incompatible with this "
+   "server. Keying Material Exporters (RFC 5705) "
+   "support missing. Upgrade to a client that "
+   "supports this feature (OpenVPN 2.6.0+).");
+return false;
+}
 if (proto & IV_PROTO_DYN_TLS_CRYPT)
 {
 o->imported_protocol_flags |= CO_USE_DYNAMIC_TLS_CRYPT;
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index e498114..1b28a19 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -1561,6 +1561,7 @@
 SHOW_STR(auth_user_pass_verify_script);
 SHOW_BOOL(auth_user_pass_verify_script_via_file);
 SHOW_BOOL(auth_token_generate);
+SHOW_BOOL(force_key_material_export);
 SHOW_INT(auth_token_lifetime);
 SHOW_STR_INLINE(auth_token_secret_file);
 #if PORT_SHARE
@@ -2802,6 +2803,11 @@
 {
 msg(M_USAGE, "--vlan-tagging requires --mode server");
 }
+
+if (options->force_key_mate

[Openvpn-devel] [PATCH applied] Re: Check PRF availability on initialisation and add --force-tls-key-material-export

2024-01-04 Thread Gert Doering 
Previous versions of the patch had issues with string concatenation
(missing whitespace) - all fixed.  Also, the manpage would claim
auto-activation of the feature, which it didn't -> fixed as well :-)

Testing with manual activation of --force-tls-key-material-export led
to the expected result - 2.6 clients could connect fine, 2.5 and earlier
were refused with a clear message:

  2024-01-03 18:35:45 AUTH: Received control message: AUTH_FAILED,Client 
incompatible with this server. Keying Material Exporters (RFC 5705) support 
missing. Upgrade to a client that supports this feature (OpenVPN 2.6.0+).

and on the server

  2024-01-03 18:37:52 us=455522 
cron2-freebsd-tc-amd64-25/2001:608:0:814::f000:21 peer-id=0 PUSH: client does 
not support TLS key material exportbut --force-tls-key-material-export is 
enabled.

so, this should help people hitting such a scenario to much better understand
what is happening, and what they can do about it.


For completeness I've tried to test this on a FreeBSD 14 system with
"--providers fips", but failed to set up OpenSSL/FIPS in a way that
actually did anything useful...  so I broke check_tls_prf_working()
manually, and the expected "auto-enable option" part works too (in v9).

Your patch has been applied to the master and release/2.6 branch (long-
term compat and better diagnostics).

commit fa7960961415fa4f368e9bbb39dc4047680ff30c (master)
commit b29ada314cc79497a1e50e29b4b72dede2955b3d (release/2.6)
Author: Arne Schwabe
Date:   Thu Jan 4 15:02:14 2024 +0100

 Check PRF availability on initialisation and add 
--force-tls-key-material-export

 Signed-off-by: Arne Schwabe 
 Acked-by: Gert Doering 
 Message-Id: <20240104140214.32196-1-g...@greenie.muc.de>
 URL: 
https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27924.html
 Signed-off-by: Gert Doering 


--
kind regards,

Gert Doering



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[Openvpn-devel] [PATCH applied] Re: Check PRF availability on initialisation and add --force-tls-key-material-export

2024-01-04 Thread Gert Doering 
Previous versions of the patch had issues with string concatenation
(missing whitespace) - all fixed.  Also, the manpage would claim
auto-activation of the feature, which it didn't -> fixed as well :-)

Testing with manual activation of --force-tls-key-material-export led
to the expected result - 2.6 clients could connect fine, 2.5 and earlier
were refused with a clear message:

  2024-01-03 18:35:45 AUTH: Received control message: AUTH_FAILED,Client 
incompatible with this server. Keying Material Exporters (RFC 5705) support 
missing. Upgrade to a client that supports this feature (OpenVPN 2.6.0+).

and on the server

  2024-01-03 18:37:52 us=455522 
cron2-freebsd-tc-amd64-25/2001:608:0:814::f000:21 peer-id=0 PUSH: client does 
not support TLS key material exportbut --force-tls-key-material-export is 
enabled.

so, this should help people hitting such a scenario to much better understand
what is happening, and what they can do about it.


For completeness I've tried to test this on a FreeBSD 14 system with
"--providers fips", but failed to set up OpenSSL/FIPS in a way that
actually did anything useful...  so I broke check_tls_prf_working()
manually, and the expected "auto-enable option" part works too.  <<< NAK!


Your patch has been applied to the master and release/2.6 branch (long-
term compat and better diagnostics).

commit 3278524247f07f6d541d29d8ca8d4fafcb623054 (master)
commit 425f7d644876755deff1946c0a3aa16f15af4adb (release/2.6)
Author: Arne Schwabe
Date:   Tue Jan 2 13:51:49 2024 +0100

 Check PRF availability on initialisation and add 
--force-tls-key-material-export

 Signed-off-by: Arne Schwabe 
 Acked-by: Gert Doering 
 Message-Id: <20240102125149.4595-1-g...@greenie.muc.de>
 URL: 
https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27903.html
 Signed-off-by: Gert Doering 


--
kind regards,

Gert Doering



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[Openvpn-devel] [PATCH v9] Check PRF availability on initialisation and add --force-tls-key-material-export

2024-01-04 Thread Gert Doering 
From: Arne Schwabe 

We now warn a user if the TLS 1.0 PRF is not supported by the cryptographic
library of the system. Also add the option --force-tls-key-material-export
that automatically rejects clients that do not support TLS Keying Material
Export and automatically enable it when TLS 1.0 PRF support is not available.

Change-Id: I04f8c7c413e7cb62c726262feee6ca89c7e86c70
Signed-off-by: Arne Schwabe 
Acked-by: Gert Doering 
---

This change was reviewed on Gerrit and approved by at least one
developer. I request to merge it to master.

Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/460
This mail reflects revision 9 of this Change.
Acked-by according to Gerrit (reflected above):
Gert Doering 


diff --git a/doc/man-sections/protocol-options.rst 
b/doc/man-sections/protocol-options.rst
index 948c0c8..8b061d2 100644
--- a/doc/man-sections/protocol-options.rst
+++ b/doc/man-sections/protocol-options.rst
@@ -242,3 +242,11 @@
   a key renegotiation begins (default :code:`3600` seconds). This feature
   allows for a graceful transition from old to new key, and removes the key
   renegotiation sequence from the critical path of tunnel data forwarding.
+
+--force-tls-key-material-export
+  This option is only available in --mode server and forces to use
+  Keying Material Exporters (RFC 5705) for clients. This can be used to
+  simulate an environment where the cryptographic library does not support
+  the older method to generate data channel keys anymore. This option is
+  intended to be a test option and might be removed in a future OpenVPN
+  version without notice.
diff --git a/src/openvpn/crypto.c b/src/openvpn/crypto.c
index e4452d7..2fca131 100644
--- a/src/openvpn/crypto.c
+++ b/src/openvpn/crypto.c
@@ -27,6 +27,7 @@
 #endif
 
 #include "syshead.h"
+#include 
 
 #include "crypto.h"
 #include "error.h"
@@ -1789,3 +1790,22 @@
 gc_free(&gc);
 return ret;
 }
+
+bool
+check_tls_prf_working(void)
+{
+/* Modern TLS libraries might no longer support the TLS 1.0 PRF with
+ * MD5+SHA1. This allows us to establish connections only
+ * with other 2.6.0+ OpenVPN peers.
+ * Do a simple dummy test here to see if it works. */
+const char *seed = "tls1-prf-test";
+const char *secret = "tls1-prf-test-secret";
+uint8_t out[8];
+uint8_t expected_out[] = { 'q', 'D', '\xfe', '%', '@', 's', 'u', '\x95' };
+
+int ret = ssl_tls1_PRF((uint8_t *)seed, (int) strlen(seed),
+   (uint8_t *)secret, (int) strlen(secret),
+   out, sizeof(out));
+
+return (ret && memcmp(out, expected_out, sizeof(out)) == 0);
+}
diff --git a/src/openvpn/crypto.h b/src/openvpn/crypto.h
index 9255d38..4201524 100644
--- a/src/openvpn/crypto.h
+++ b/src/openvpn/crypto.h
@@ -593,4 +593,12 @@
 return kt;
 }
 
+/**
+ * Checks if the current TLS library supports the TLS 1.0 PRF with MD5+SHA1
+ * that OpenVPN uses when TLS Keying Material Export is not available.
+ *
+ * @return  true if supported, false otherwise.
+ */
+bool check_tls_prf_working(void);
+
 #endif /* CRYPTO_H */
diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c
index 8b490ed..f4f0b8a 100644
--- a/src/openvpn/multi.c
+++ b/src/openvpn/multi.c
@@ -1830,6 +1830,16 @@
 {
 o->imported_protocol_flags |= CO_USE_TLS_KEY_MATERIAL_EXPORT;
 }
+else if (o->force_key_material_export)
+{
+msg(M_INFO, "PUSH: client does not support TLS Keying Material "
+"Exporters but --force-tls-key-material-export is enabled.");
+auth_set_client_reason(tls_multi, "Client incompatible with this "
+   "server. Keying Material Exporters (RFC 5705) "
+   "support missing. Upgrade to a client that "
+   "supports this feature (OpenVPN 2.6.0+).");
+return false;
+}
 if (proto & IV_PROTO_DYN_TLS_CRYPT)
 {
 o->imported_protocol_flags |= CO_USE_DYNAMIC_TLS_CRYPT;
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index e498114..1b28a19 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -1561,6 +1561,7 @@
 SHOW_STR(auth_user_pass_verify_script);
 SHOW_BOOL(auth_user_pass_verify_script_via_file);
 SHOW_BOOL(auth_token_generate);
+SHOW_BOOL(force_key_material_export);
 SHOW_INT(auth_token_lifetime);
 SHOW_STR_INLINE(auth_token_secret_file);
 #if PORT_SHARE
@@ -2802,6 +2803,11 @@
 {
 msg(M_USAGE, "--vlan-tagging requires --mode server");
 }
+
+if (options->force_key_material_export)
+{
+msg(M_USAGE, "--force-tls-key-material-export requires --mode 
server");
+}
 }
 
 /*
@@ -3634,6 +3640,30 @@
 }
 
 static void
+options_process_mutate_prf(struct options *o)
+{
+if (!check_tls_prf_working())
+{
+msg(D_TLS_ERRORS, "Warning: TLS 1.0 PRF with MD5+SHA1 PRF is not "
+"supported by the TLS library. Your system does not suppo

[Openvpn-devel] [M] Change in openvpn[master]: Check PRF availability on initialisation and add --force-tls-key-mate...

2024-01-04 Thread cron2 (Code Review) 
Attention is currently required from: flichtenheld, plaisthos.

cron2 has posted comments on this change. ( 
http://gerrit.openvpn.net/c/openvpn/+/460?usp=email )

Change subject: Check PRF availability on initialisation and add 
--force-tls-key-material-export
..


Patch Set 9: Code-Review+2

(1 comment)

Patchset:

PS9:
back to +2 - manipulating expected_out or setting ret=0 now leads to "it 
failed!" and the code as is pretends the PRF worked.  Didn't test FIPS mode, 
but "set ret=0" as a test case should be good enough.



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Gerrit-Project: openvpn
Gerrit-Branch: master
Gerrit-Change-Id: I04f8c7c413e7cb62c726262feee6ca89c7e86c70
Gerrit-Change-Number: 460
Gerrit-PatchSet: 9
Gerrit-Owner: plaisthos 
Gerrit-Reviewer: cron2 
Gerrit-Reviewer: flichtenheld 
Gerrit-CC: openvpn-devel 
Gerrit-Attention: plaisthos 
Gerrit-Attention: flichtenheld 
Gerrit-Comment-Date: Thu, 04 Jan 2024 14:01:55 +
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[Openvpn-devel] [M] Change in openvpn[master]: Check PRF availability on initialisation and add --force-tls-key-mate...

2024-01-04 Thread plaisthos (Code Review) 
Attention is currently required from: cron2, flichtenheld.

plaisthos has posted comments on this change. ( 
http://gerrit.openvpn.net/c/openvpn/+/460?usp=email )

Change subject: Check PRF availability on initialisation and add 
--force-tls-key-material-export
..


Patch Set 8:

(1 comment)

File src/openvpn/crypto.c:

http://gerrit.openvpn.net/c/openvpn/+/460/comment/46b9a5e4_f4d733cf :
PS8, Line 1809: return (ret && memcmp(out, expected_out, sizeof(out)) != 0);
> It pains me to return to "-2" again, but there is something really weird 
> going on here - to see what […]
O my got I really butchered that one.



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Gerrit-Project: openvpn
Gerrit-Branch: master
Gerrit-Change-Id: I04f8c7c413e7cb62c726262feee6ca89c7e86c70
Gerrit-Change-Number: 460
Gerrit-PatchSet: 8
Gerrit-Owner: plaisthos 
Gerrit-Reviewer: cron2 
Gerrit-Reviewer: flichtenheld 
Gerrit-CC: openvpn-devel 
Gerrit-Attention: cron2 
Gerrit-Attention: flichtenheld 
Gerrit-Comment-Date: Thu, 04 Jan 2024 12:45:54 +
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[Openvpn-devel] [M] Change in openvpn[master]: Check PRF availability on initialisation and add --force-tls-key-mate...

2024-01-04 Thread plaisthos (Code Review) 
Attention is currently required from: flichtenheld, plaisthos.

Hello cron2, flichtenheld,

I'd like you to reexamine a change. Please visit

http://gerrit.openvpn.net/c/openvpn/+/460?usp=email

to look at the new patch set (#9).


Change subject: Check PRF availability on initialisation and add 
--force-tls-key-material-export
..

Check PRF availability on initialisation and add --force-tls-key-material-export

We now warn a user if the TLS 1.0 PRF is not supported by the cryptographic
library of the system. Also add the option --force-tls-key-material-export
that automatically rejects clients that do not support TLS Keying Material
Export and automatically enable it when TLS 1.0 PRF support is not available.

Change-Id: I04f8c7c413e7cb62c726262feee6ca89c7e86c70
Signed-off-by: Arne Schwabe 
---
M doc/man-sections/protocol-options.rst
M src/openvpn/crypto.c
M src/openvpn/crypto.h
M src/openvpn/multi.c
M src/openvpn/options.c
M src/openvpn/options.h
6 files changed, 84 insertions(+), 0 deletions(-)


  git pull ssh://gerrit.openvpn.net:29418/openvpn refs/changes/60/460/9

diff --git a/doc/man-sections/protocol-options.rst 
b/doc/man-sections/protocol-options.rst
index 948c0c8..8b061d2 100644
--- a/doc/man-sections/protocol-options.rst
+++ b/doc/man-sections/protocol-options.rst
@@ -242,3 +242,11 @@
   a key renegotiation begins (default :code:`3600` seconds). This feature
   allows for a graceful transition from old to new key, and removes the key
   renegotiation sequence from the critical path of tunnel data forwarding.
+
+--force-tls-key-material-export
+  This option is only available in --mode server and forces to use
+  Keying Material Exporters (RFC 5705) for clients. This can be used to
+  simulate an environment where the cryptographic library does not support
+  the older method to generate data channel keys anymore. This option is
+  intended to be a test option and might be removed in a future OpenVPN
+  version without notice.
diff --git a/src/openvpn/crypto.c b/src/openvpn/crypto.c
index e4452d7..2fca131 100644
--- a/src/openvpn/crypto.c
+++ b/src/openvpn/crypto.c
@@ -27,6 +27,7 @@
 #endif

 #include "syshead.h"
+#include 

 #include "crypto.h"
 #include "error.h"
@@ -1789,3 +1790,22 @@
 gc_free(&gc);
 return ret;
 }
+
+bool
+check_tls_prf_working(void)
+{
+/* Modern TLS libraries might no longer support the TLS 1.0 PRF with
+ * MD5+SHA1. This allows us to establish connections only
+ * with other 2.6.0+ OpenVPN peers.
+ * Do a simple dummy test here to see if it works. */
+const char *seed = "tls1-prf-test";
+const char *secret = "tls1-prf-test-secret";
+uint8_t out[8];
+uint8_t expected_out[] = { 'q', 'D', '\xfe', '%', '@', 's', 'u', '\x95' };
+
+int ret = ssl_tls1_PRF((uint8_t *)seed, (int) strlen(seed),
+   (uint8_t *)secret, (int) strlen(secret),
+   out, sizeof(out));
+
+return (ret && memcmp(out, expected_out, sizeof(out)) == 0);
+}
diff --git a/src/openvpn/crypto.h b/src/openvpn/crypto.h
index 9255d38..4201524 100644
--- a/src/openvpn/crypto.h
+++ b/src/openvpn/crypto.h
@@ -593,4 +593,12 @@
 return kt;
 }

+/**
+ * Checks if the current TLS library supports the TLS 1.0 PRF with MD5+SHA1
+ * that OpenVPN uses when TLS Keying Material Export is not available.
+ *
+ * @return  true if supported, false otherwise.
+ */
+bool check_tls_prf_working(void);
+
 #endif /* CRYPTO_H */
diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c
index 8b490ed..f4f0b8a 100644
--- a/src/openvpn/multi.c
+++ b/src/openvpn/multi.c
@@ -1830,6 +1830,16 @@
 {
 o->imported_protocol_flags |= CO_USE_TLS_KEY_MATERIAL_EXPORT;
 }
+else if (o->force_key_material_export)
+{
+msg(M_INFO, "PUSH: client does not support TLS Keying Material "
+"Exporters but --force-tls-key-material-export is enabled.");
+auth_set_client_reason(tls_multi, "Client incompatible with this "
+   "server. Keying Material Exporters (RFC 5705) "
+   "support missing. Upgrade to a client that "
+   "supports this feature (OpenVPN 2.6.0+).");
+return false;
+}
 if (proto & IV_PROTO_DYN_TLS_CRYPT)
 {
 o->imported_protocol_flags |= CO_USE_DYNAMIC_TLS_CRYPT;
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index e498114..1b28a19 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -1561,6 +1561,7 @@
 SHOW_STR(auth_user_pass_verify_script);
 SHOW_BOOL(auth_user_pass_verify_script_via_file);
 SHOW_BOOL(auth_token_generate);
+SHOW_BOOL(force_key_material_export);
 SHOW_INT(auth_token_lifetime);
 SHOW_STR_INLINE(auth_token_secret_file);
 #if PORT_SHARE
@@ -2802,6 +2803,11 @@
 {
 msg(M_USAGE, "--vlan-tagging requires --mode server");
 }
+
+if (op