Internal PCI Scan on Tenable.io website. Of course after register account.
2017-04-30 9:11 GMT+02:00 Aki Tuomi <aki.tuomi@dovecot.fi>:
What kind of test are you running?
Aki
On April 27, 2017 at 12:00 PM Poliman - Serwis <serwis@poliman.pl> wrote:
I turned of ssl_cipher_list in dovecot.conf file (so it's default) but test still gives errors: Apr 27 08:55:06 serwer-1 dovecot: pop3-login: Error: SSL: Stacked error: error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol Apr 27 08:55:06 serwer-1 dovecot: pop3-login: Error: SSL: Stacked error: error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol Apr 27 08:55:07 serwer-1 dovecot: pop3-login: Error: SSL: Stacked error: error:1408A10B:SSL routines:ssl3_get_client_hello:wrong version number Apr 27 08:55:07 serwer-1 dovecot: pop3-login: Error: SSL: Stacked error: error:1408A10B:SSL routines:ssl3_get_client_hello:wrong version number Apr 27 08:55:15 serwer-1 dovecot: imap-login: Error: SSL: Stacked error: error:1408F119:SSL routines:SSL3_GET_RECORD:decryption failed or bad record mac Apr 27 08:55:15 serwer-1 dovecot: pop3-login: Error: SSL: Stacked error: error:1408F119:SSL routines:SSL3_GET_RECORD:decryption failed or bad record mac Apr 27 08:55:17 serwer-1 dovecot: imap-login: Error: SSL: Stacked error: error:1408F119:SSL routines:SSL3_GET_RECORD:decryption failed or bad record mac Apr 27 08:55:17 serwer-1 dovecot: pop3-login: Error: SSL: Stacked error: error:1408F119:SSL routines:SSL3_GET_RECORD:decryption failed or bad record mac Apr 27 08:55:18 serwer-1 dovecot: imap-login: Error: SSL: Stacked error: error:1408A0E3:SSL routines:ssl3_get_client_hello:parse tlsext Apr 27 08:55:18 serwer-1 dovecot: imap-login: Error: SSL: Stacked error: error:1408A0E3:SSL routines:ssl3_get_client_hello:parse tlsext Apr 27 08:55:19 serwer-1 dovecot: pop3-login: Error: SSL: Stacked error: error:1408A0E3:SSL routines:ssl3_get_client_hello:parse tlsext
2017-04-27 10:34 GMT+02:00 Poliman - Serwis <serwis@poliman.pl>:
Cipher list which You post provide better compatibility or security than those which I currently have? On older software version these cipher list works well and not generate any errors when I run Internal PCI scan test from https://cloud.tenable.com for another server. But for new server with newer software during test I got errors in mail.err.
2017-04-27 10:00 GMT+02:00 Aki Tuomi <aki.tuomi@dovecot.fi>:
On April 27, 2017 at 10:55 AM Poliman - Serwis <serwis@poliman.pl> wrote:
Thank You for answers. But:
- How should be properly configured ssl_cipher_list?
ssl_cipher_list = ALL:!kRSA:!SRP:!kDHd:!DSS:!aNU LL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@STRENGTH
To disable non-EC DH, use:
ssl_cipher_list = ALL:!DH:!kRSA:!SRP:!kDHd:!DSS: !aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@STRENGTH
- Ok, removed !TLSv1 !TLSv1.1.
- Strange thing with ssl_protocols and ssl_cipher_list, because on older server on Ubuntu 14.04 LTS, dovecot 2.2.9 and postfix 2.11.0 these
lines looks exactly this same and no errors in mail.err file and mailes works without any problem. 4. No, currently I don't use LMTP.
it is possible that postfix is not causing this error.
2017-04-27 8:25 GMT+02:00 Aki Tuomi <aki.tuomi@dovecot.fi>:
> On April 27, 2017 at 8:12 AM Poliman - Serwis <
> > > Hi, > To default dovecot.conf file I added (based on found documentation): > ssl = required > disable_plaintext_auth = yes #change default 'no' to 'yes' > ssl_prefer_server_ciphers = yes > ssl_options = no_compression > ssl_dh_parameters_length = 2048 > ssl_cipher_list = > ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256: ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384: DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+ AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128- SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE- RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA- AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE- RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256: DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256: AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128- SHA:AES256-SHA:AES:CAMELLIA:!aNULL:!eNULL:!EXPORT:!DES:! RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES- CBC3-SHA:!KRB5-DES-CBC3-SHA >
This looks rather cumbersome way to define ciphers.
> 1. Are these settings good or can be improved? > 2. Is this line proper: > ssl_protocols = !SSLv2 !SSLv3 !TLSv1 !TLSv1.1
Well if you only want to support TLSv1.2, which might lead into
serwis@poliman.pl> wrote: trouble.
> or maybe should be: > ssl_protocols = !SSLv2 !SSLv3 > 3. Last thing. I have below errors (they appear in loop in
mail.err log
> file): > #Apr 25 14:08:09 serwer-1 dovecot: imap-login: Error: SSL: Stacked error: > error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown
two protocol
> #Apr 25 14:08:09 serwer-1 dovecot: imap-login: Error: SSL: Stacked error: > error:1408A10B:SSL routines:ssl3_get_client_hello:wrong version number > #Apr 25 14:08:51 serwer-1 dovecot: imap-login: Error: SSL: Stacked error: > error:1408F119:SSL routines:SSL3_GET_RECORD:decryption failed or bad record > mac > #Apr 25 14:08:51 serwer-1 dovecot: imap-login: Error: SSL: Stacked error: > error:1408A0C1:SSL routines:ssl3_get_client_hello:no shared cipher
This means your client did not support your enabled ciphers.
> > When I setup in postfix main.cf file (other lines default): > tls_ssl_options = no_ticket, no_compression > tls_preempt_cipherlist = yes > smtpd_sasl_security_options=noanonymous,noplaintext > smtpd_sasl_tls_security_options=noanonymous,noplaintext > smtpd_tls_mandatory_ciphers = high > smtpd_tls_dh1024_param_file = /etc/postfix/dh2048.pem > #instead of below I tried smtpd_tls_mandatory_exclude_ciphers but I don't > know what should be setup > smtpd_tls_exclude_ciphers = aNULL, eNULL, EXPORT, DES, RC4, MD5, PSK, > aECDH, EDH-DSS-DES-CBC3-SHA, EDH-RSA-DES-CBC3-SHA, ECDHE-RSA-DES-CBC3-SHA, > DES-CBC3-SHA, RC4-MD5, RC4-SHA, ECDHE-RSA-RC4-SHA > smtp_tls_exclude_ciphers = aNULL, eNULL, EXPORT, DES, RC4, MD5, PSK, aECDH, > EDH-DSS-DES-CBC3-SHA, EDH-RSA-DES-CBC3-SHA, ECDHE-RSA-DES-CBC3-SHA, > DES-CBC3-SHA, RC4-MD5, RC4-SHA, ECDHE-RSA-RC4-SHA > > Is between dovecot and postfix some communication using above ciphers or > something that generate that errors in log or maybe some public client try > connect and can't establish connection? >
If you are using LMTP, then some of those settings will cause changes in how LMTP works as well.
> Server with Ubuntu 16.04 LTS, postfix 3.1 and dovecot 2.2.22 and openssl > 1.0.2k. > -- > > *Pozdrawiam / Best Regards* > *Piotr Bracha* > > > > > *tel. 534 555 877* > > *serwis@poliman.pl <serwis@poliman.pl>*
Aki
--
*Pozdrawiam / Best Regards* *Piotr Bracha*
*tel. 534 555 877*
*serwis@poliman.pl <serwis@poliman.pl>*
--
*Pozdrawiam / Best Regards* *Piotr Bracha*
*tel. 534 555 877*
*serwis@poliman.pl <serwis@poliman.pl>*
--
*Pozdrawiam / Best Regards* *Piotr Bracha*
*tel. 534 555 877*
*serwis@poliman.pl <serwis@poliman.pl>*
--
*Pozdrawiam / Best Regards* *Piotr Bracha*
*tel. 534 555 877*
*serwis@poliman.pl <serwis@poliman.pl>*