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I generated self-signed certificate with latest Ubuntu OS and OpenSSL in it. Certificate has RSA 4096 and SHA512...but it uses SSLv3 and from mozilla I can not access the web page because Mozilla does not support SSLv3 anymore. How can I generate cert. that uses TLS?

pa4080
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John
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  • Whatever your problem is you will have to provide more information about your configuration. The SSL/TLS protocol version used is unrelated to the certificate you use. The SSL/TLS protocol used is more to do with the version and configuration of OpenSSL/your web server. – Matt Caswell Apr 10 '17 at 19:02
  • I think the problem is in the web server's configuration. You need to disable SSL 3.0 and Weak Ciphers. Please edit the question and tag the kind of your web server - Apache or Nginx, also provide its version. Also and the OpenSSL version. You can type apt show openssl and apt show apache2 or apt show nginx to check them. – pa4080 Apr 10 '17 at 22:06

1 Answers1

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The problem is with the web server's configuration. You need to disable SSLv3 and Weak Ciphers.

Things that matter in this case are: the web server's kind, its version and the version of OpenSSL. By default in Ubuntu 16.04 this are:

An example of Apache2 VirtualHost configuration:

<VirtualHost *:443>
    ...
    SSLEngine on
    SSLCertificateFile     /path/to/signed_certificate_followed_by_intermediate_certs
    SSLCertificateKeyFile   /path/to/private/key

    # Uncomment the following directive when using client certificate authentication
    #SSLCACertificateFile    /path/to/ca_certs_for_client_authentication


    # HSTS (mod_headers is required) (15768000 seconds = 6 months)
    Header always set Strict-Transport-Security "max-age=15768000"
    ...
</VirtualHost>

# Spas's note: you can leave next lines here or you can put them
# into '/etc/apache2/mods-available/ssl.conf' or into '/etc/apache2/apache2.conf'

# intermediate configuration, tweak to your needs
SSLProtocol             all -SSLv2 -SSLv3 -TLSv1
SSLCipherSuite          ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS
SSLHonorCipherOrder     on
SSLCompression          off
SSLSessionTickets       off

# OCSP Stapling, only in httpd 2.3.3 and later
SSLUseStapling          on
SSLStaplingResponderTimeout 5
SSLStaplingReturnResponderErrors off
SSLStaplingCache        shmcb:/var/run/ocsp(128000)

An example of Nginx configuration:

server {
    listen 80 default_server;
    listen [::]:80 default_server;

    # Redirect all HTTP requests to HTTPS with a 301 Moved Permanently response.
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;

    # certs sent to the client in SERVER HELLO are concatenated in ssl_certificate
    ssl_certificate /path/to/signed_cert_plus_intermediates;
    ssl_certificate_key /path/to/private_key;
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:50m;
    ssl_session_tickets off;

    # Diffie-Hellman parameter for DHE ciphersuites, recommended 2048 bits
    ssl_dhparam /path/to/dhparam.pem;

    # intermediate configuration. tweak to your needs. 
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    # Spas's note: You can remove also TLSv1 from this list.
    ssl_ciphers 'ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS';
    ssl_prefer_server_ciphers on;

    # HSTS (ngx_http_headers_module is required) (15768000 seconds = 6 months)
    add_header Strict-Transport-Security max-age=15768000;

    # OCSP Stapling ---
    # fetch OCSP records from URL in ssl_certificate and cache them
    ssl_stapling on;
    ssl_stapling_verify on;

    ## verify chain of trust of OCSP response using Root CA and Intermediate certs
    ssl_trusted_certificate /path/to/root_CA_cert_plus_intermediates;

    resolver <IP DNS resolver>;

    ....
}

Sources:

Configuration check:

Read also:

pa4080
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    Guys, thanks a lot! You helped me to understand that the problem is with the web server's configuration and not the certificate I generated. On this link https://www.ssllabs.com/ssltest/analyze.html I tested my certificate and this also helped me. Thanks. – John Apr 11 '17 at 08:26