docs/manual/mod/mod_session_crypto.xml

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<modulesynopsis metafile="mod_session_crypto.xml.meta">

<name>mod_session_crypto</name>
<description>Session encryption support</description>
<status>Extension</status>
<sourcefile>mod_session_crypto.c</sourcefile>
<identifier>session_crypto_module</identifier>
<compatibility>Available in Apache 2.3 and later</compatibility>

<summary>
    <note type="warning"><title>Warning</title>
      <p>The session modules make use of HTTP cookies, and as such can fall
      victim to Cross Site Scripting attacks, or expose potentially private
      information to clients. Please ensure that the relevant risks have
      been taken into account before enabling the session functionality on
      your server.</p>
    </note>

    <p>This submodule of <module>mod_session</module> provides support for the
    encryption of user sessions before being written to a local database, or
    written to a remote browser via an HTTP cookie.</p>
    
    <p>This can help provide privacy to user sessions where the contents of
    the session should be kept private from the user, or where protection is
    needed against the effects of cross site scripting attacks.</p>
    
    <p>For more details on the session interface, see the documentation for
    the <module>mod_session</module> module.</p>
    
</summary>
<seealso><module>mod_session</module></seealso>
<seealso><module>mod_session_cookie</module></seealso>
<seealso><module>mod_session_dbd</module></seealso>

    <section id="basicusage"><title>Basic Usage</title>
    
      <p>To create a simple encrypted session and store it in a cookie called
      <var>session</var>, configure the session as follows:</p>
      
      <example><title>Browser based encrypted session</title>
        Session On<br />
        SessionCookieName session path=/<br />
        SessionCryptoPassphrase secret
      </example>
      
      <p>The session will be encrypted with the given key. Different servers can
      be configured to share sessions by ensuring the same encryption key is used
      on each server.</p>
      
      <p>If the encryption key is changed, sessions will be invalidated
      automatically.</p>
      
      <p>For documentation on how the session can be used to store username
      and password details, see the <module>mod_auth_form</module> module.</p>

    </section>

<directivesynopsis>
<name>SessionCryptoPassphrase</name>
<description>The key used to encrypt the session</description>
<syntax>SessionCryptoPassphrase <var>secret</var></syntax>
<default>none</default>
<contextlist><context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<compatibility>Available in Apache 2.3.0 and later</compatibility>

<usage>
    <p>The <directive>SessionCryptoPassphrase</directive> directive specifies the key
    to be used to enable symmetrical encryption on the contents of the session before
    writing the session, or decrypting the contents of the session after reading the session.</p>

    <p>Keys are more secure when they are long, and consist of truly random characters.
    Changing the key on a server has the effect of invalidating all existing sessions.</p>

    <p>If the <directive module="mod_session_crypto">SessionCryptoCertificateFile</directive>
    directive is set and asymmetrical encryption is enabled instead, the
    <directive module="mod_session_crypto">SessionCryptoPassphrase</directive> directive
    will be interpreted as the passphrase of the key, if the key is encrypted.</p>

</usage>
</directivesynopsis>

<directivesynopsis>
<name>SessionCryptoCertificateFile</name>
<description>The certificate used to encrypt and decrypt the session</description>
<syntax>SessionCryptoCertificateFile <var>file</var></syntax>
<default>none</default>
<contextlist><context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<compatibility>Available in Apache 2.3.0 and later</compatibility>

<usage>
    <p>The <directive>SessionCryptoCertificateFile</directive> directive specifies the name
    of a certificate to be used to asymmetrically encrypt the contents of the session before
    writing the session, or decrypting the content of the session after reading the session.</p>

    <p>Changing the certificate on a server has the effect of invalidating all existing
    sessions.</p>

    <p>If the key associated with this certificate is protected with a passphrase, the
    <directive module="mod_session_crypto">SessionCryptoPassphrase</directive> directive
    will be interpreted as the passphrase to use to decrypt the key.</p>

    <note type="warning"><title>Experimental</title>
      <p>This directive is dependent on experimental support for asymmetrical encryption
      support currently available in prerelease versions of OpenSSL, and will only be
      available on platforms that support it.</p>
    </note>
    
</usage>
</directivesynopsis>

<directivesynopsis>
<name>SessionCryptoCertificateKeyFile</name>
<description>The certificate key used to encrypt and decrypt the session</description>
<syntax>SessionCryptoCertificateKeyFile <var>file</var></syntax>
<default>none</default>
<contextlist><context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<compatibility>Available in Apache 2.3.0 and later</compatibility>

<usage>
    <p>The <directive>SessionCryptoCertificateKeyFile</directive> directive specifies the name
    of a certificate key to be used alongside a certificate to encrypt the contents of the
    session before writing the session, or decrypting the content of the session after reading
    the session.</p>
    
    <p>Changing the certificate or key on a server has the effect of invalidating all existing
    sessions.</p>

    <p>If this key is protected with a passphrase, the
    <directive module="mod_session_crypto">SessionCryptoPassphrase</directive> directive
    will be interpreted as the passphrase to use to decrypt the key.</p>

    <note type="warning"><title>Experimental</title>
      <p>This directive is dependent on experimental support for asymmetrical encryption
      support currently available in prerelease versions of OpenSSL, and will only be
      available on platforms that support it.</p>
    </note>
    
</usage>
</directivesynopsis>

<directivesynopsis>
<name>SessionCryptoCipher</name>
<description>The name of the cipher to use during encryption / decryption</description>
<syntax>SessionCryptoCipher <var>cipher</var></syntax>
<default>AES256</default>
<contextlist><context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<compatibility>Available in Apache 2.3.0 and later</compatibility>

<usage>
    <p>The <directive>SessionCryptoCipher</directive> directive specifies the name
    of the cipher to use during encryption. The ciphers available will depend on the
    underlying encryption toolkit on the server platform.</p>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>SessionCryptoDigest</name>
<description>The name of the digest to use during encryption / decryption</description>
<syntax>SessionCryptoDigest <var>cipher</var></syntax>
<default>SHA</default>
<contextlist><context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<compatibility>Available in Apache 2.3.0 and later</compatibility>

<usage>
    <p>The <directive>SessionCryptoDigest</directive> directive specifies the name
    of the digest to use during encryption. The list of digests available will depend
    on the underlying encryption toolkit on the server platform.</p>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>SessionCryptoEngine</name>
<description>The name of the engine to use during encryption / decryption</description>
<syntax>SessionCryptoEngine <var>engine</var></syntax>
<default>none</default>
<contextlist><context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<compatibility>Available in Apache 2.3.0 and later</compatibility>

<usage>
    <p>The <directive>SessionCryptoEngine</directive> directive specifies the name
    of the engine to use during encryption, depending on the capabilities of the
    underlying encryption toolkit on the server platform.</p>
</usage>
</directivesynopsis>

</modulesynopsis>