
<sect1 id="sslinfo">
 <title>sslinfo</title>
 
 <indexterm zone="sslinfo">
  <primary>sslinfo</primary>
 </indexterm>

 <para>
  This modules provides information about current SSL certificate for PostgreSQL.
 </para>

 <sect2>
  <title>Notes</title>
  <para>
   This extension won't build unless your PostgreSQL server is configured
   with --with-openssl.  Information provided with these functions would
   be completely useless if you don't use SSL to connect to database.
  </para>
 </sect2>

 <sect2>
  <title>Functions Description</title>
  
  <itemizedlist>
   <listitem>
    <programlisting>
ssl_is_used() RETURNS boolean;
    </programlisting>
    <para>
     Returns TRUE, if current connection to server uses SSL and FALSE
     otherwise.
    </para>
   </listitem>

   <listitem>
    <programlisting>
ssl_client_cert_present() RETURNS boolean
    </programlisting>
    <para>
     Returns TRUE if current client have presented valid SSL client
     certificate to the server and FALSE otherwise (e.g., no SSL,
     certificate hadn't be requested by server).
    </para>
   </listitem>
  
   <listitem>
    <programlisting>
ssl_client_serial() RETURNS numeric
    </programlisting>
    <para>
     Returns serial number of current client certificate.  The combination
     of certificate serial number and certificate issuer is guaranteed to
     uniquely identify certificate (but not its owner -- the owner ought to
     regularily change his keys, and get new certificates from the issuer).
    </para>
    <para>
     So, if you run you own CA and allow only certificates from this CA to
     be accepted by server, the serial number is the most reliable (albeit
     not very mnemonic) means to indentify user.
    </para>
   </listitem>

   <listitem>
    <programlisting>
ssl_client_dn() RETURNS text
    </programlisting>
    <para>
     Returns the full subject of current client certificate, converting
     character data into the current database encoding.  It is assumed that
     if you use non-Latin characters in the certificate names, your
     database is able to represent these characters, too.  If your database
     uses the SQL_ASCII encoding, non-Latin characters in the name will be
     represented as UTF-8 sequences.
    </para>
    <para>
     The result looks like '/CN=Somebody /C=Some country/O=Some organization'.
    </para>
   </listitem>
 
   <listitem>
    <programlisting>
ssl_issuer_dn()
    </programlisting>
    <para>
     Returns the full issuer name of the client certificate, converting
     character data into current database encoding.
    </para>
    <para>
     The combination of the return value of this function with the
     certificate serial number uniquely identifies the certificate.
    </para>
    <para>
     The result of this function is really useful only if you have more
     than one trusted CA certificate in your server's root.crt file, or if
     this CA has issued some intermediate certificate authority
     certificates.
    </para>
   </listitem>
 
   <listitem>
    <programlisting>
ssl_client_dn_field(fieldName text) RETURNS text
    </programlisting>
    <para>
     This function returns the value of the specified field in the
     certificate subject.  Field names are string constants that are
     converted into ASN1 object identificators using the OpenSSL object
     database.  The following values are acceptable:
    </para>
    <programlisting>
commonName (alias CN)
surname (alias SN)
name
givenName (alias GN)
countryName (alias C) 
localityName (alias L)
stateOrProvinceName (alias ST)
organizationName (alias O)
organizationUnitName (alias OU)
title
description
initials
postalCode
streetAddress
generationQualifier
description
dnQualifier
x500UniqueIdentifier
pseudonim
role
emailAddress
    </programlisting>
    <para>
     All of these fields are optional, except commonName.  It depends
     entirely on your CA policy which of them would be included and which
     wouldn't.  The meaning of these fields, howeer, is strictly defined by
     the X.500 and X.509 standards, so you cannot just assign arbitrary
     meaning to them.
    </para>
   </listitem>
 
   <listitem>
    <programlisting>
ssl_issuer_field(fieldName text) RETURNS text;
    </programlisting>
    <para>
     Does same as ssl_client_dn_field, but for the certificate issuer
     rather than the certificate subject.
    </para>
   </listitem>
  </itemizedlist>
 </sect2>

 <sect2>
  <title>Author</title>
  <para>
   Victor Wagner <email>vitus@cryptocom.ru</email>, Cryptocom LTD
   E-Mail of Cryptocom OpenSSL development group: 
   <email>openssl@cryptocom.ru</email>
  </para>
 </sect2>
</sect1>

