From d799553eb16e6fe9a057e4f57d73db13e1aa786f Mon Sep 17 00:00:00 2001 From: Edward Rudd Date: Fri, 22 Jul 2011 09:32:25 -0400 Subject: move project page to ooo-pages branch --- docs/index.xml | 915 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 915 insertions(+) create mode 100644 docs/index.xml (limited to 'docs') diff --git a/docs/index.xml b/docs/index.xml new file mode 100644 index 0000000..5e150d1 --- /dev/null +++ b/docs/index.xml @@ -0,0 +1,915 @@ + + + +
+ +
+
+

Compilation

+

+ mod_gnutls uses the "configure/make/make install" + mechanism common to many Open Source programs. + Most of the dirty work is handled by either configure or + Apache's apxs utility. If you have built Apache modules before, there + shouldn't be any surprises for you. +

+

+ The interesting options you can pass to configure are:

+
    +
  • --with-apxs=/path/to/apache/dir/bin/apxs +

    + This option is used to specify the location of the + apxs utility that was installed as part of apache. + Specify the location of the binary, not the directory + it is located in. +

    +
    • +
  • --with-libgnutls=PATH +

    Full path to the libgnutls-config program.

    +
    • +
  • --with-apr-memcache=PREFIX +

    Prefix to where apr_memcache is installed.

    +
    • +
  • --help +

    Provides a list of available configure options.

    +
    • +
+
./configure --with-apxs=/usr/sbin/apxs2 --with-libgnutls=/usr
+make
+make install
+
+
+
+

Integration into Apache

+

To activate mod_gnutls Just add

+ LoadModule gnutls_module modules/mod_gnutls.so + to your httpd.conf and restart Apache. +

+
+
+

Examples

+

Some example configuration and the exported variables to scripts can be + found in the following sections:

+ +
+ +
+

Standard SSL Example

+

The following is an example of standard SSL Hosting, using one IP Addresses for each virtual host:

+
+# Load the module into Apache.
+LoadModule gnutls_module modules/mod_gnutls.so
+
+GnuTLSCache dbm /var/cache/www-tls-cache
+GnuTLSCacheTimeout 500
+
+# With normal SSL Websites, you need one IP Address per-site.
+Listen 1.2.3.1:443
+Listen 1.2.3.2:443
+Listen 1.2.3.3:443
+Listen 1.2.3.4:443
+
+<VirtualHost 1.2.3.1:443>
+    GnuTLSEnable on
+    GnuTLSPriorities NONE:+AES-128-CBC:+3DES-CBC:+ARCFOUR-128:+RSA:+DHE-RSA:+DHE-DSS:+SHA1:+MD5:+COMP-NULL
+    DocumentRoot /www/site1.example.com/html
+    ServerName site1.example.com:443
+    GnuTLSCertificateFile conf/ssl/site1.crt
+    GnuTLSKeyFile conf/ss/site1.key
+</VirtualHost>
+<VirtualHost 1.2.3.2:443>
+# This virtual host enables SRP authentication
+    GnuTLSEnable on
+    GnuTLSPriorities NORMAL:+SRP
+    DocumentRoot /www/site2.example.com/html
+    ServerName site2.example.com:443
+    GnuTLSSRPPasswdFile conf/ssl/tpasswd.site2
+    GnuTLSSRPPasswdConfFile conf/ssl/tpasswd.site2.conf
+</VirtualHost>
+<VirtualHost 1.2.3.3:443>
+# This server enables SRP, OpenPGP and X.509 authentication.
+    GnuTLSEnable on
+    GnuTLSPriorities NORMAL:+SRP:+SRP-RSA:+SRP-DSS
+    DocumentRoot /www/site3.example.com/html
+    ServerName site3.example.com:443
+    GnuTLSCertificateFile conf/ssl/site3.crt
+    GnuTLSKeyFile conf/ss/site3.key
+    GnuTLSClientVerify ignore
+    GnuTLSPGPCertificateFile conf/ss/site3.pub.asc
+    GnuTLSPGPKeyFile conf/ss/site3.sec.asc
+    GnuTLSSRPPasswdFile conf/ssl/tpasswd.site3
+    GnuTLSSRPPasswdConfFile conf/ssl/tpasswd.site3.conf
+</VirtualHost>
+<VirtualHost 1.2.3.4:443>
+    GnuTLSEnable on
+# %COMPAT disables some security features to enable maximum compatibility with clients.
+    GnuTLSPriorities NONE:+AES-128-CBC:+ARCFOUR-128:+RSA:+SHA1:+MD5:+COMP-NULL:%COMPAT
+    DocumentRoot /www/site4.example.com/html
+    ServerName site4.example.com:443
+    GnuTLSCertificateFile conf/ssl/site4.crt
+    GnuTLSKeyFile conf/ss/site4.key
+</VirtualHost>
+
+
+
+

Server Name Indication Example

+

mod_gnutls can also use 'Server Name Indication', as specified in +RFC 3546. This allows hosting many SSL Websites, with a Single IP Address. Currently all the recent +browsers support this standard. Here is an example, using SNI: +

+
+# Load the module into Apache.
+LoadModule gnutls_module modules/mod_gnutls.so
+
+# With normal SSL Websites, you need one IP Address per-site.
+Listen 1.2.3.1:443
+# This could also be 'Listen *:443',
+# just like '*:80' is common for non-https
+
+# No caching. Enable session tickets. Timeout is still used for
+# ticket expiration.
+GnuTLSCacheTimeout 600
+
+# This tells apache, that for this IP/Port combination, we want to use
+# Name Based Virtual Hosting.  In the case of Server Name Indication,
+# it lets mod_gnutls pick the correct Server Certificate.
+NameVirtualHost 1.2.3.1:443
+
+<VirtualHost 1.2.3.1:443>
+    GnuTLSEnable on
+    GnuTLSSessionTickets on
+    GnuTLSPriorities NORMAL
+    DocumentRoot /www/site1.example.com/html
+    ServerName site1.example.com:443
+    GnuTLSCertificateFile conf/ssl/site1.crt
+    GnuTLSKeyFile conf/ss/site1.key
+</VirtualHost>
+<VirtualHost 1.2.3.1:443>
+    GnuTLSEnable on
+    GnuTLSPriorities NORMAL
+    DocumentRoot /www/site2.example.com/html
+    ServerName site2.example.com:443
+    GnuTLSCertificateFile conf/ssl/site2.crt
+    GnuTLSKeyFile conf/ss/site2.key
+</VirtualHost>
+<VirtualHost 1.2.3.1:443>
+    GnuTLSEnable on
+    GnuTLSPriorities NORMAL
+    DocumentRoot /www/site3.example.com/html
+    ServerName site3.example.com:443
+    GnuTLSCertificateFile conf/ssl/site3.crt
+    GnuTLSKeyFile conf/ss/site3.key
+</VirtualHost>
+<VirtualHost 1.2.3.1:443>
+    GnuTLSEnable on
+    GnuTLSPriorities NORMAL
+    DocumentRoot /www/site4.example.com/html
+    ServerName site4.example.com:443
+    GnuTLSCertificateFile conf/ssl/site4.crt
+    GnuTLSKeyFile conf/ss/site4.key
+</VirtualHost>
+
+
+
+

Performance Issues

+

mod_gnutls by default uses conservative settings for the + server. You can fine tune the configuration to reduce the load on a busy + server. The following examples do exactly this. +

+
+# Load the module into Apache.
+LoadModule gnutls_module modules/mod_gnutls.so
+
+# Using 4 memcache servers to distribute the SSL Session Cache.
+GnuTLSCache memcache "mc1.example.com mc2.example.com mc3.example.com mc4.example.com"
+GnuTLSCacheTimeout 600
+
+Listen 1.2.3.1:443
+NameVirtualHost 1.2.3.1:443
+
+<VirtualHost 1.2.3.1:443>
+    GnuTLSEnable on
+# Here we disable the Perfect forward secrecy ciphersuites (DHE)
+# and disallow AES-256 since AES-128 is just fine.
+    GnuTLSPriorities NORMAL:!DHE-RSA:!DHE-DSS:!AES-256-CBC:%COMPAT
+    DocumentRoot /www/site1.example.com/html
+    ServerName site1.example.com:443
+    GnuTLSCertificateFile conf/ssl/site1.crt
+    GnuTLSKeyFile conf/ss/site1.key
+</VirtualHost>
+<VirtualHost 1.2.3.1:443>
+    GnuTLSEnable on
+# Here we instead of disabling the DHE ciphersuites we use
+# Diffie Hellman parameters of smaller size than the default (2048 bits).
+# Using small numbers from 768 to 1024 bits should be ok once they are
+# regenerated every few hours.
+# Use "certtool --generate-dh-params --bits 1024" to get those
+    GnuTLSDHFile /etc/apache2/dh.params
+    GnuTLSPriorities NORMAL:!AES-256-CBC:%COMPAT
+    DocumentRoot /www/site2.example.com/html
+    ServerName site2.example.com:443
+    GnuTLSCertificateFile conf/ssl/site2.crt
+    GnuTLSKeyFile conf/ss/site2.key
+</VirtualHost>
+
+
+ +
+

Environment variables

+

mod_gnutls exports the following environment variables to + scripts. +

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
HTTPS:can be "on" or "off"
SSL_VERSION_LIBRARY: The version of the gnutls library
SSL_VERSION_INTERFACE: The version of this module
SSL_PROTOCOL: The SSL or TLS protocol name (such as "TLS 1.0" etc.)
SSL_CIPHER: The SSL or TLS cipher suite name.
SSL_COMPRESS_METHOD: The negotiated compression method (NULL or DEFLATE)
SSL_SRP_USER: The SRP username used for authentication.
SSL_CIPHER_USEKEYSIZE and SSL_CIPHER_ALGKEYSIZE: The number if bits used in the used cipher + algorithm. This does not fully reflect the security level since the size of + RSA or DHE key exchange parameters affect the security level too.
SSL_CIPHER_EXPORT: true or false. Whether the cipher suite negotiated is an export one.
SSL_SESSION_ID: The session ID negotiated in this session. Can be the same during + client reloads.
SSL_CLIENT_V_REMAIN: The number of days until the client's certificate is expired.
SSL_CLIENT_V_START: The activation time of client's certificate.
SSL_CLIENT_V_END: The expiration time of client's certificate.
SSL_CLIENT_S_DN: The distinguished name of client's certificate in RFC2253 format.
SSL_CLIENT_I_DN: The distinguished name of client's issuer certificate in RFC2253 format.
SSL_CLIENT_S_AN%: These will contain the alternative names of the client certificate + (% is a number starting from zero). The values will be prepended by "DNSNAME:", + "RFC822NAME:" or "URI:" depending on the type. If it is not supported the value + "UNSUPPORTED" will be set.
SSL_CLIENT_M_SERIAL: The serial number of the client's certificate.
SSL_CLIENT_M_VERSION: The version of the client's certificate.
SSL_CLIENT_A_SIG: The algorithm used for the signature in client's certificate.
SSL_CLIENT_A_KEY: The public key algorithm in client's certificate.
SSL_CLIENT_CERT: The PEM-encoded client certificate
SSL_CLIENT_VERIFY: whether the client's certificate was verified. (NONE if none was sent, or SUCCESS or FAILED)
SSL_CLIENT_CERT_TYPE: The certificate type can be X.509 or OPENPGP.
SSL_SERVER_V_START: The activation time of server's certificate.
SSL_SERVER_V_END: The expiration time of server's certificate.
SSL_SERVER_S_DN: The distinguished name of the server's certificate in RFC2253 format.
SSL_SERVER_I_DN: The distinguished name of the server's issuer certificate in RFC2253 format.
SSL_SERVER_S_AN%: These will contain the alternative names of the server certificate + (% is a number starting from zero). The values will be prepended by "DNSNAME:", + "RFC822NAME:" or "URI:" depending on the type. If it is not supported the value + "UNSUPPORTED" will be set.
SSL_SERVER_M_SERIAL: The serial number of the server's certificate.
SSL_SERVER_M_VERSION: The version of the server's certificate.
SSL_SERVER_A_SIG: The algorithm used for the signature in server's certificate.
SSL_SERVER_A_KEY: The public key algorithm in server's certificate.
SSL_SERVER_CERT: The PEM-encoded server certificate
SSL_SERVER_CERT_TYPE: The certificate type can be X.509 or +OPENPGP.
+
+ +
+

GnuTLSCache

+ + + + + + + + + + + + + + + + + +
Description:Configure SSL Session Cache
Syntax:GnuTLSCache [dbm|gdbm|memcache|none] [path|server list|-]
Default:dbm "conf/gnutls_cache"
Context: + global config +
+

This directive configures the SSL Session Cache for mod_gnutls. + This could be shared between machines of different architectures. +

+
+
dbm
+
+ Uses the default Berkeley DB backend of APR DBM to cache SSL Sessions results. The argument is a relative or absolute path to be used + as the DBM Cache file. This is compatible with most operating systems. +
+ +
gdbm
+
+ Uses the GDBM backend of APR DBM to cache SSL Sessions results. The argument is a relative or absolute path to be used + as the DBM Cache file. +
+ +
memcache
+
+ Uses a memcached server to cache the SSL Session. + The argument is a space separated list of servers. If no port number is supplied, + the default of 11211 is used. This can be used to share a session cache between all servers in a cluster. +
+ +
None
+
+ Turns off all caching of SSL Sessions. This can significantly reduce the performance of mod_gnutls + since even followup connections by a client must renegotiate + parameters instead of reusing old ones. +
+
+Example Usage: +
GnuTLSCache memcache "10.0.0.1 10.0.0.2 10.0.0.3"
+
+ +
+

GnuTLSCacheTimeout

+ + + + + + + + + + + + + + + + + +
Description:Timeout for SSL Session Cache expiration.
Syntax:GnuTLSCacheTimeout seconds
Default:300
Context: + global config +
+

+ Sets the timeout for SSL Session Cache entries expiration. This directive + is valid even if Session Tickets are used, and indicates the + expiration time of the ticket. +

+
+ +
+

GnuTLSSessionTickets

+ + + + + + + + + + + + + + + + + +
Description:Enable Session Tickets for the server.
Syntax:GnuTLSSessionTickets [on|off]
Default:off
Context: + server config, + virtual host. +
+

+ To avoid storing data for TLS session resumption it is allowed + to provide client with a ticket, to use on return. Use for servers + with limited storage, and don't combine with GnuTLSCache. For a pool + of servers this option is not recommended since the tickets are + unique for the issuing server only. +

+
+ +
+

GnuTLSCertificateFile

+ + + + + + + + + + + + + + + + + +
Description:Set to the PEM Encoded Server Certificate.
Syntax:GnuTLSCertificateFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to a PEM Encoded Certificate to use as this Server's + Certificate. +

+Example Usage: +
GnuTLSCertificateFile conf/ssl/server.crt
+
+ +
+

GnuTLSPGPCertificateFile

+ + + + + + + + + + + + + + + + + +
Description:Set to a base64 Encoded Server OpenPGP Certificate.
Syntax:GnuTLSPGPCertificateFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to a base64 Encoded OpenPGP Certificate to use as this Server's + Certificate. +

+Example Usage: +
GnuTLSPGPCertificateFile conf/ssl/server.asc
+
+ + +
+

GnuTLSClientVerify

+ + + + + + + + + + + + + + + + + +
Description:Enable Client Certificate Verification
Syntax:GnuTLSClientVerify [ignore|request|require|
Default:ignore
Context: + server config, + virtual host, + directory, + .htaccess +
+

This directive controls the use of SSL Client Certificate Authentication. If used in the .htaccess + context, it can force TLS re-negotiation. +

+
+
ignore
+
mod_gnutls will ignore the contents of any SSL Client Certificates sent. + It will not request that the client sends a certificate. +
+ +
request
+
The client certificate will be requested, but not required. The Certificate will be validated if sent. The output of the validation status will be stored in the SSL_CLIENT_VERIFY environment variable and can be "SUCCESS", "FAILED" or "NONE".
+ +
require
+
A Client certificate will be required. Any requests without a valid client certificate will be denied. The SSL_CLIENT_VERIFY environment variable will only be set to "SUCCESS".
+
+ 
<Directory "/path/to/my/docroot">
+    GnuTLSClientVerify require
+</Directory>
+
+ +
+

GnuTLSClientCAFile

+ + + + + + + + + + + + + + + + + +
Description:Set to the PEM Encoded Certificate Authority Certificate.
Syntax:GnuTLSClientCAFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to a PEM Encoded Certificate to use as a Certificate Authority with Client Certificate Authentication. This file may contain a list of trusted authorities. +

+Example Usage: +
GnuTLSClientCAFile conf/ssl/ca.crt
+
+ +
+

GnuTLSPGPKeyringFile

+ + + + + + + + + + + + + + + + + +
Description:Set to a base64 Encoded key ring.
Syntax:GnuTLSPGPKeyringFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to a base64 Encoded Certificate + list (key ring) to use as a means of verification of Client + Certificates. This file should contain a list of trusted signers. +

+Example Usage: +
GnuTLSPGPKeyringFile conf/ssl/ring.asc
+
+ +
+

GnuTLSEnable

+ + + + + + + + + + + + + + + + + +
Description:Enable GnuTLS for this virtual host.
Syntax:GnuTLSEnable [on|off]
Default:off
Context: + virtual host +
+

This directive enables SSL/TLS Encryption for a Virtual Host. +

+
<VirtualHost 1.2.3.4:443>
+    GnuTLSEnable on
+    # other directives for the Virtual Host.
+</VirtualHost>
+
+ +
+

GnuTLSExportCertificates

+ + + + + + + + + + + + + + + + + +
Description:Export the PEM encoded certificates to CGIs.
Syntax:GnuTLSExportCertificates [on|off]
Default:off
Context: + virtual host +
+

This directive enables exporting the full PEM encoded certificates of + the server and the client to CGIs. This makes mod_gnutls export exactly the same environment variables as mod_ssl. +

+
<VirtualHost 1.2.3.4:443>
+    GnuTLSExportCertificates on
+    # other directives for the Virtual Host.
+</VirtualHost>
+
+ + +
+

GnuTLSKeyFile

+ + + + + + + + + + + + + + + + + +
Description:Set to the Server Private Key.
Syntax:GnuTLSKeyFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to the Server Private Key. This key cannot currently be password protected. +

+Example Usage: +
GnuTLSKeyFile conf/ssl/server.key
+
+ Security Warning: This private key must be protected. It is read while Apache is still running as root, + and does not need to be readable by the nobody or apache user. +
+
+ +
+

GnuTLSPGPKeyFile

+ + + + + + + + + + + + + + + + + +
Description:Set to the Server OpenPGP Secret Key.
Syntax:GnuTLSPGPKeyFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to the Server Private Key. This key cannot currently be password protected. +

+Example Usage: +
GnuTLSPGPKeyFile conf/ssl/server.asc
+
+ Security Warning: This private key must be protected. It is read while Apache is still running as root, + and does not need to be readable by the nobody or apache user. +
+
+ + +
+

GnuTLSDHFile

+ + + + + + + + + + + + + + + + + +
Description:Set to the PKCS #3 encoded Diffie Hellman parameters.
Syntax:GnuTLSDHFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to a PKCS #3 encoded DH parameters. Those are used when the DHE key exchange method is enabled. You can generate this file using + "certtool --generate-dh-params --bits 2048". If not set mod_gnutls will use the included parameters. +

+Example Usage: +
GnuTLSDHFile conf/ssl/dhparams
+
+ +
+

GnuTLSRSAFile

+ + + + + + + + + + + + + + + + + +
Description:Set to the PKCS #1 encoded RSA parameters for 'EXPORT' ciphersuites.
Syntax:GnuTLSRSAFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to a PKCS #1 encoded RSA parameters. Those are used when the RSA-EXPORT key exchange method is enabled. You can generate this file using "certtool --generate-privkey --bits 512". These parameters should not contain key of longer of 512 bits (due to the export restrictions). If not set mod_gnutls will not negotiate the 'EXPORT' ciphersuites. It is recommended not to enable those ciphersuites. If you do make sure you regenerate this file at every few hours. +

+Example Usage: +
GnuTLSRSAFile conf/ssl/rsaparams
+
+ +
+

GnuTLSSRPPasswdFile

+ + + + + + + + + + + + + + + + + +
Description:Set to the SRP password file for SRP ciphersuites.
Syntax:GnuTLSSRPPasswdFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to an SRP password file. This is the same format as used in libsrp. You can generate such file using the command "srptool --passwd /etc/tpasswd --passwd-conf /etc/tpasswd.conf -u test" to set a password for user test. This password file holds the username, a password verifier and the dependency to the SRP parameters. +

+Example Usage: +
GnuTLSSRPPasswdFile conf/ssl/tpasswd
+
+ +
+

GnuTLSSRPPasswdConfFile

+ + + + + + + + + + + + + + + + + +
Description:Set to the SRP password.conf file for SRP ciphersuites.
Syntax:GnuTLSSRPPasswdConfFile file-path
Default:none
Context: + server config, + virtual host. +
+

Takes an absolute or relative path to an SRP password.conf file. This is the same format as used in libsrp. You can generate such file using the command "srptool --create-conf /etc/tpasswd.conf". This file holds the SRP parameters and is associate with the password file (the verifiers depends on these parameters). +

+Example Usage: +
GnuTLSSRPPasswdConfFile conf/ssl/tpasswd.conf
+
+ +
+

GnuTLSPriorities

+ + + + + + + + + + + + + + + + + +
Description:Set the allowed ciphers, key exchange algorithms, MACs and + compression methods.
Syntax:GnuTLSPriorities +cipher0:+cipher1:...:+cipherN
Default:none
Context: + server config, + virtual host. +
+

Takes a semi-colon separated list of ciphers, key exchange methods + Message authentication codes and compression methods to enable. The + allowed keywords are specified in the gnutls_priority_init() + function of GnuTLS. It's documentation can be found at + Core + GnuTLS functions. +

+ In brief you can specify a set of ciphersuites from the choices: +

    +
  • NONE: The empty list.
    • +
  • EXPORT: A list with all the supported cipher combinations + including the "EXPORT" strength algorithms.
    • +
  • PERFORMANCE: A list with all the secure cipher combinations + sorted in terms of performance.
    • +
  • NORMAL: A list with all the secure cipher combinations + sorted with respect to security margin (subjective term).
    • +
  • SECURE: A list with all the secure cipher combinations including the + 256-bit ciphers sorted with respect to security margin.
    • +
+ Additionally you can add or remove algorithms using the "+" and "!" + prefixes respectively. That is in order to disable the ARCFOUR cipher + from the "NORMAL" set you can use the string + NORMAL:!ARCFOUR-128. Other options such as the protocol + version and the compression method can be specified using the + VERS- and COMP- prefixes. So in order to + remove or add a specific TLS version from the "NORMAL" set use + NORMAL:!VERS-SSL3.0. To enable + zlib compression use NORMAL:+COMP-DEFLATE. + However it is recommended not to add compression at this level. + With the "NONE" set, in order to be usable, you have to specify a complete + set of combinations of protocol versions, cipher algorithms + (AES-128-CBC), key exchange algorithms (RSA), message authentication + codes (SHA1) and compression methods (COMP-NULL). +

+ All the supported algorithms are: +

    +
  • Ciphers: AES-256-CBC, AES-128-CBC, CAMELLIA-256-CBC, + CAMELLIA-128-CBC, ARCFOUR-128, 3DES-CBC, ARCFOUR-40
    • +
  • Key exchange methods: RSA, DHE-RSA, DHE-DSS, SRP, SRP-RSA, + SRP-DSS, ANON-DH
    • +
  • Message authentication codes: SHA1, MD5
    • +
  • Compression methods: COMP-DEFLATE, COMP-NULL
    • +
  • Protocol versions: VERS-TLS1.1, VERS-TLS1.0, VERS-SSL3.0
    • +
+

+

The special keyword "%COMPAT" will disable some security features + such as protection against statistical attacks to ciphertext data in + order to achieve maximum compatibility (some broken mobile clients need + this). +

+Example Usage: +
GnuTLSPriorities NORMAL:!AES-256-CBC:!DHE-RSA
+
GnuTLSPriorities EXPORT:!VERS-TLS1.0:+COMP-DEFLATE:+CTYPE-OPENPGP
+
GnuTLSPriorities NONE:+VERS-TLS1.0:+AES-128-CBC:+RSA:+SHA1:+COMP-NULL
+
GnuTLSPriorities NORMAL:+COMP-DEFLATE
+
GnuTLSPriorities NORMAL:%COMPAT
+
GnuTLSPriorities NORMAL:+ANON-DH
+
+ +
+ +
+ + -- cgit