> From: [email protected] On Behalf Of Kurt Roeckx > Sent: Thursday, 13 June, 2013 03:13
> > When talking to an exchange server I get some weird behaviour when > > using the 1.0.1e version. I get a TLS 1.0 connection, but the > > problems go away when using -no_tls1_2 > > If you got an agreed protocol, then it isn't the "1.2-ClientHello got bigger" problem. > > An example connection is with: > > openssl s_client -connect mail.megacontractinginc.com:25 > -starttls smtp -crlf -quiet > > > > 1) > > << 250 OK > > >> HELP > > << 214-This server supports the following commands: > > << 214 HELO EHLO STARTTLS RCPT DATA RSET MAIL QUIT HELP > AUTH TURN ETRN BDAT VRFY > > 140527452698280:error:1408F10B:SSL > routines:SSL3_GET_RECORD:wrong version number:s3_pkt.c:337: > > That's really weird, unless the server isn't actually doing starttls correctly (in spite of offering it). If you can get this to recur, try with -state -debug to see exactly where/what is happening. > > 2) > > << 250 OK > > >> MAIL FROM: [email protected] > > << 250 2.1.0 [email protected] OK > > >> HELP > > > > The connection hangs at this point, any command will hang it. > > > > I don't see why the -no_tls1_2 should have any effect on it. > > One thing I've noticed is that -no_tls1_2 has as effect that the > cipher gets changed from DES-CBC3-SHA to RC4-MD5. > I don't see why that would result; -no_tls1_2 excludes the 1.2-only suites (SHA2 and GCM) from ClientHello, but it still has akRSA-DES3CBC preferred over akRSA-RC4 (and akRSA-RC4-SHA over akRSA-RC4-MD5!). Are you sure there's nothing else different? Can you get a wire trace, or -msg or -debug? But given it happened, it means that the "empty_fragment" (0/N) CBC patch now used against BEAST becomes inapplicable. If this server/stack could be one of the ones rumored to not support 0/N (even though MS did implement 1/N in Jan. 2012 for BEAST, the infamous MS12-006) try s_client with -bugs . -debug might also be worth trying here if (most? of) your inputs and outputs are long enough to be distinguished at granularity 8 (DES block size). ______________________________________________________________________ OpenSSL Project http://www.openssl.org Development Mailing List [email protected] Automated List Manager [email protected]
