Jos Vos wrote:
Hi,
I'm trying to "port" OpenVPN to a rather old Linux system (for
certain reasons...). I tried both 2.0.9 and 2.1_rc9. What I found:
Compiling works ok for both versions (after a few trivial compiler
compatibility fixes).
But when testing a loopback connection with the loopback-{client,server}
sample config files, this works ok for 2.0.9, but it fails for 2.1rc9 and
the error I get is "could not extract Common Name from X509 subject":
Fri Aug 8 10:33:40 2008 TLS: Initial packet from 127.0.0.1:56975, sid=2ca3e519
1141a566
Fri Aug 8 10:33:40 2008 TLS: Initial packet from 127.0.0.1:56974, sid=ec182881
010bc533
Fri Aug 8 10:33:40 2008 VERIFY OK: depth=1,
/C=KG/ST=NA/L=BISHKEK/O=OpenVPN-TEST/Email=me@myhost.mydomain
Fri Aug 8 10:33:40 2008 VERIFY ERROR: could not extract Common Name from X509
subject string
('/C=KG/ST=NA/O=OpenVPN-TEST/CN=Test-Server/Email=me@myhost.mydomain') -- note
that the Common Name length is limited to 64 characters
Fri Aug 8 10:33:40 2008 TLS_ERROR: BIO read tls_read_plaintext error:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify
failed
Fri Aug 8 10:33:40 2008 TLS Error: TLS object -> incoming plaintext read error
Fri Aug 8 10:33:40 2008 TLS Error: TLS handshake failed
Fri Aug 8 10:33:40 2008 TCP/UDP: Closing socket
Fri Aug 8 10:33:40 2008 Closing TUN/TAP interface
Looking at the code (ssl.c, verify_callback()) I see that in the 2.0.9
version the code is somewhat different and that no error checking is
done after the extract_x509_field() call.
The OpenSSL version used on the old system is 0.9.6b. Does this mean
that OpenVPN is not compatible with OpenSSL 0.9.6b and that I also
should not use 2.0.9 with that version (although at first sight the
test does not show any problems)? Or should I look somewhere else?
OpenVPN is supposed to build with OpenSSL 0.9.6 or higher.
There is a bug in OpenSSL 0.9.6b ASN1_STRING_to_UTF8, which the new
implementation of extract_x509_field_ssl depends on. I've merged a
workaround:
-r3220 http://svn.openvpn.net/projects/openvpn/branches/BETA21
The workaround will be present in 2.1-rc10.
James
