• Please be aware: Kaspersky Anti-Virus has been deprecated
    With the upgrade to Plesk Obsidian 18.0.64, "Kaspersky Anti-Virus for Servers" will be automatically removed from the servers it is installed on. We recommend that you migrate to Sophos Anti-Virus for Servers.
  • The Horde webmail has been deprecated. Its complete removal is scheduled for April 2025. For details and recommended actions, see the Feature and Deprecation Plan.
  • We’re working on enhancing the Monitoring feature in Plesk, and we could really use your expertise! If you’re open to sharing your experiences with server and website monitoring or providing feedback, we’d love to have a one-hour online meeting with you.

Question Nginx compile by Plesk and chipers

OverWolf

Regular Pleskian
Hi,
I'm on CentOS7 with Plesk 18.0.39 and I use nginx as a proxy.In my configuration TLS 1.3 isn't implementable but with nginx complied by Plesk, I can secure my domains with the last version.
I use Let'sEncrypt to secure domains but I have a question about this; my domains are secured with TLS_AES_256_GCM_SHA384, but I would like to use TLS_AES_128_GCM_SHA256.

These are my ssl-chipers from plesk bin server_pref -s (https://support.plesk.com/hc/en-us/...able-TLS-protocol-versions-in-Plesk-for-Linux)

Code:
ssl-protocols:  TLSv1 TLSv1.1 TLSv1.2 TLSv1.3
ssl-ciphers:   EECDH+AESGCM+AES128:EECDH+AESGCM+AES256:EECDH+CHACHA20:EDH+AESGCM+AES128:EDH+AESGCM+AES256:EDH+CHACHA20:EECDH+SHA256+AES128:EECDH+SHA384+AES256:EDH+SHA256+AES128:EDH+SHA256+AES256:EECDH+SHA1+AES128:EECDH+SHA1+AES256:EDH+SHA1+AES128:EDH+SHA1+AES256:EECDH+HIGH:EDH+HIGH:AESGCM+AES128:AESGCM+AES256:CHACHA20:SHA256+AES128:SHA256+AES256:SHA1+AES128:SHA1+AES256:HIGH:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!3DES:!MD5:!PSK:!KRB5:!aECDH:!kDH
ssl-cipher-server-order:        true


This is my ssl.conf from /etc/nginx/conf.d/

Code:
ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;
ssl_protocols  TLSv1 TLSv1.1 TLSv1.2 TLSv1.3;
ssl_prefer_server_ciphers on;


I have tried to change chipers order in server_pref without success because give me an error in httpd/conf.d/ssl.conf, so this is my question: how can I do this ?

Thank you
 
OK, but ... why?
TLS handshake should end up with the strongest cipher supported by both server and client, so, works as intended?
 
Hi,

TLS AES 256 has large key size and it require more CPU. So 256-bit version is a bit slower and when you have many call to your site. 128bit is still safe but faster. If you take a look at the biggest e-commerce website, they use 128 and not 256.
 
Hi,

I've tried to implement new chipers, but I have an httpd error when I apply it :

Code:
plesk bin server_pref -u -ssl-ciphers 'TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305'

Error :

Code:
AH00526: Syntax error on line 81 of /etc/httpd/conf.d/ssl.conf:
SSLCipherSuite takes one argument, Colon-delimited list of permitted SSL Ciphers ('XXX:...:XXX' - see manual)
httpd.

I know that the error are the new chipers TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256, that have _ and not - , but I don't know how to resolve my problem.

Where I can change chipers order on CentOs7 ?

Thank you.
 
I know that the error are the new chipers TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256, that have _ and not - , but I don't know how to resolve my problem.
Tried on my test Plesk server without any errors:

Code:
# plesk bin server_pref -u -ssl-ciphers 'TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305'
SUCCESS: Server preferences are successfully updated

Looks like your /etc/httpd/conf.d/ssl.conf misconfigured.
 
Hi IgorG,

have you tested it on CentOS 7 machine ?

My ssl.conf has default configuration


Code:
#
# When we also provide SSL we have to listen to the
# the HTTPS port in addition.
#
Listen 7081

##
##  SSL Global Context
##
##  All SSL configuration in this context applies both to
##  the main server and all SSL-enabled virtual hosts.
##

#   Pass Phrase Dialog:
#   Configure the pass phrase gathering process.
#   The filtering dialog program (`builtin' is a internal
#   terminal dialog) has to provide the pass phrase on stdout.
SSLPassPhraseDialog exec:/usr/libexec/httpd-ssl-pass-dialog

#   Inter-Process Session Cache:
#   Configure the SSL Session Cache: First the mechanism
#   to use and second the expiring timeout (in seconds).
SSLSessionCache         shmcb:/run/httpd/sslcache(512000)
SSLSessionCacheTimeout  300

#   Pseudo Random Number Generator (PRNG):
#   Configure one or more sources to seed the PRNG of the
#   SSL library. The seed data should be of good random quality.
#   WARNING! On some platforms /dev/random blocks if not enough entropy
#   is available. This means you then cannot use the /dev/random device
#   because it would lead to very long connection times (as long as
#   it requires to make more entropy available). But usually those
#   platforms additionally provide a /dev/urandom device which doesn't
#   block. So, if available, use this one instead. Read the mod_ssl User
#   Manual for more details.
SSLRandomSeed startup file:/dev/urandom  256
SSLRandomSeed connect builtin
#SSLRandomSeed startup file:/dev/random  512
#SSLRandomSeed connect file:/dev/random  512
#SSLRandomSeed connect file:/dev/urandom 512

#
# Use "SSLCryptoDevice" to enable any supported hardware
# accelerators. Use "openssl engine -v" to list supported
# engine names.  NOTE: If you enable an accelerator and the
# server does not start, consult the error logs and ensure
# your accelerator is functioning properly.
#
SSLCryptoDevice builtin
#SSLCryptoDevice ubsec

##
## SSL Virtual Host Context
##

#<VirtualHost _default_:443>
#
## General setup for the virtual host, inherited from global configuration
##DocumentRoot "/var/www/html"
##ServerName www.example.com:443
#
## Use separate log files for the SSL virtual host; note that LogLevel
## is not inherited from httpd.conf.
#ErrorLog logs/ssl_error_log
#TransferLog logs/ssl_access_log
#LogLevel warn
#
##   SSL Engine Switch:
##   Enable/Disable SSL for this virtual host.
#SSLEngine on
#
##   SSL Protocol support:
## List the enable protocol levels with which clients will be able to
## connect.  Disable SSLv2 access by default:
SSLProtocol +TLSv1.1 +TLSv1.2
#
##   SSL Cipher Suite:
##   List the ciphers that the client is permitted to negotiate.
##   See the mod_ssl documentation for a complete list.
SSLCipherSuite ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384
#
##   Speed-optimized SSL Cipher configuration:
##   If speed is your main concern (on busy HTTPS servers e.g.),
##   you might want to force clients to specific, performance
##   optimized ciphers. In this case, prepend those ciphers
##   to the SSLCipherSuite list, and enable SSLHonorCipherOrder.
##   Caveat: by giving precedence to RC4-SHA and AES128-SHA
##   (as in the example below), most connections will no longer
##   have perfect forward secrecy - if the server's key is
##   compromised, captures of past or future traffic must be
##   considered compromised, too.
##SSLCipherSuite RC4-SHA:AES128-SHA:HIGH:MEDIUM:!aNULL:!MD5
SSLHonorCipherOrder on
#
##   Server Certificate:
## Point SSLCertificateFile at a PEM encoded certificate.  If
## the certificate is encrypted, then you will be prompted for a
## pass phrase.  Note that a kill -HUP will prompt again.  A new
## certificate can be generated using the genkey(1) command.
#SSLCertificateFile /etc/pki/tls/certs/localhost.crt
#
##   Server Private Key:
##   If the key is not combined with the certificate, use this
##   directive to point at the key file.  Keep in mind that if
##   you've both a RSA and a DSA private key you can configure
##   both in parallel (to also allow the use of DSA ciphers, etc.)
#SSLCertificateKeyFile /etc/pki/tls/private/localhost.key
#
##   Server Certificate Chain:
##   Point SSLCertificateChainFile at a file containing the
##   concatenation of PEM encoded CA certificates which form the
##   certificate chain for the server certificate. Alternatively
##   the referenced file can be the same as SSLCertificateFile
##   when the CA certificates are directly appended to the server
##   certificate for convinience.
##SSLCertificateChainFile /etc/pki/tls/certs/server-chain.crt
#
##   Certificate Authority (CA):
##   Set the CA certificate verification path where to find CA
##   certificates for client authentication or alternatively one
##   huge file containing all of them (file must be PEM encoded)
##SSLCACertificateFile /etc/pki/tls/certs/ca-bundle.crt
#
##   Client Authentication (Type):
##   Client certificate verification type and depth.  Types are
##   none, optional, require and optional_no_ca.  Depth is a
##   number which specifies how deeply to verify the certificate
##   issuer chain before deciding the certificate is not valid.
##SSLVerifyClient require
##SSLVerifyDepth  10
#
##   Access Control:
##   With SSLRequire you can do per-directory access control based
##   on arbitrary complex boolean expressions containing server
##   variable checks and other lookup directives.  The syntax is a
##   mixture between C and Perl.  See the mod_ssl documentation
##   for more details.
##<Location />
##SSLRequire (    %{SSL_CIPHER} !~ m/^(EXP|NULL)/ \
##            and %{SSL_CLIENT_S_DN_O} eq "Snake Oil, Ltd." \
##            and %{SSL_CLIENT_S_DN_OU} in {"Staff", "CA", "Dev"} \
##            and %{TIME_WDAY} >= 1 and %{TIME_WDAY} <= 5 \
##            and %{TIME_HOUR} >= 8 and %{TIME_HOUR} <= 20       ) \
##           or %{REMOTE_ADDR} =~ m/^192\.76\.162\.[0-9]+$/
##</Location>
#
##   SSL Engine Options:
##   Set various options for the SSL engine.
##   o FakeBasicAuth:
##     Translate the client X.509 into a Basic Authorisation.  This means that
##     the standard Auth/DBMAuth methods can be used for access control.  The
##     user name is the `one line' version of the client's X.509 certificate.
##     Note that no password is obtained from the user. Every entry in the user
##     file needs this password: `xxj31ZMTZzkVA'.
##   o ExportCertData:
##     This exports two additional environment variables: SSL_CLIENT_CERT and
##     SSL_SERVER_CERT. These contain the PEM-encoded certificates of the
##     server (always existing) and the client (only existing when client
##     authentication is used). This can be used to import the certificates
##     into CGI scripts.
##   o StdEnvVars:
##     This exports the standard SSL/TLS related `SSL_*' environment variables.
##     Per default this exportation is switched off for performance reasons,
##     because the extraction step is an expensive operation and is usually
##     useless for serving static content. So one usually enables the
##     exportation for CGI and SSI requests only.
##   o StrictRequire:
##     This denies access when "SSLRequireSSL" or "SSLRequire" applied even
##     under a "Satisfy any" situation, i.e. when it applies access is denied
##     and no other module can change it.
##   o OptRenegotiate:
##     This enables optimized SSL connection renegotiation handling when SSL
##     directives are used in per-directory context.
##SSLOptions +FakeBasicAuth +ExportCertData +StrictRequire
#<Files ~ "\.(cgi|shtml|phtml|php3?)$">
#    SSLOptions +StdEnvVars
#</Files>
#<Directory "/var/www/cgi-bin">
#    SSLOptions +StdEnvVars
#</Directory>
#
##   SSL Protocol Adjustments:
##   The safe and default but still SSL/TLS standard compliant shutdown
##   approach is that mod_ssl sends the close notify alert but doesn't wait for
##   the close notify alert from client. When you need a different shutdown
##   approach you can use one of the following variables:
##   o ssl-unclean-shutdown:
##     This forces an unclean shutdown when the connection is closed, i.e. no
##     SSL close notify alert is send or allowed to received.  This violates
##     the SSL/TLS standard but is needed for some brain-dead browsers. Use
##     this when you receive I/O errors because of the standard approach where
##     mod_ssl sends the close notify alert.
##   o ssl-accurate-shutdown:
##     This forces an accurate shutdown when the connection is closed, i.e. a
##     SSL close notify alert is send and mod_ssl waits for the close notify
##     alert of the client. This is 100% SSL/TLS standard compliant, but in
##     practice often causes hanging connections with brain-dead browsers. Use
##     this only for browsers where you know that their SSL implementation
##     works correctly.
##   Notice: Most problems of broken clients are also related to the HTTP
##   keep-alive facility, so you usually additionally want to disable
##   keep-alive for those clients, too. Use variable "nokeepalive" for this.
##   Similarly, one has to force some clients to use HTTP/1.0 to workaround
##   their broken HTTP/1.1 implementation. Use variables "downgrade-1.0" and
##   "force-response-1.0" for this.
#BrowserMatch "MSIE [2-5]" \
#         nokeepalive ssl-unclean-shutdown \
#         downgrade-1.0 force-response-1.0
#
##   Per-Server Logging:
##   The home of a custom SSL log file. Use this when you want a
##   compact non-error SSL logfile on a virtual host basis.
#CustomLog logs/ssl_request_log \
#          "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
#
#</VirtualHost>
 
Back
Top