Added session abstraction.

Added sysconfig.pm which allows for LedgerSMB configuration parameters to be 
stored in a separate namespace.


git-svn-id: https://ledger-smb.svn.sourceforge.net/svnroot/ledger-smb/trunk@222 4979c152-3d1c-0410-bac9-87ea11338e46

1 files changed, 157 insertions, 0 deletions

diff --git a/LedgerSMB/Session/DB.pm b/LedgerSMB/Session/DB.pm
new file mode 100755
index 00000000..0c8dda45
--- /dev/null
+++ b/LedgerSMB/Session/DB.pm
@@ -0,0 +1,157 @@
+#=====================================================================
+# LedgerSMB 
+# Small Medium Business Accounting software
+# http://www.ledgersmb.org/
+# 
+#
+# Copyright (C) 2006
+# This work contains copyrighted information from a number of sources all used
+# with permission.  It is released under the GNU General Public License 
+# Version 2 or, at your option, any later version.  See COPYRIGHT file for 
+# details.
+#
+#
+#======================================================================
+#
+# This file has undergone whitespace cleanup.
+#
+#======================================================================
+# This package contains session related functions:
+#
+# check - checks validity of session based on the user's cookie and login
+#
+# create - creates a new session, writes cookie upon success
+#
+# destroy - destroys session
+#====================================================================
+package Session;
+
+sub session_check {
+
+	my ($cookie, $form, %myconfig) = @_;
+	my ($sessionid, $token) = split /:/, $cookie;
+
+	# connect to database
+	my $dbh = DBI->connect($myconfig{dbconnect}, $myconfig{dbuser}, $myconfig{dbpasswd});
+
+	my $checkQuery = $dbh->prepare("SELECT sl_login FROM session WHERE session_id = ? AND token = ? AND last_used > now() - ?::interval");
+
+	my $updateAge = $dbh->prepare("UPDATE session SET last_used = now() WHERE session_id = ?;");
+
+	#must be an integer
+	$sessionid =~ s/[^0-9]//g;
+	$sessionid = int $sessionid;
+
+	#must be 32 chars long and contain hex chars
+	$token =~ s/[^0-9a-f]//g;
+	$token = substr($token, 0, 32);
+
+	if (!$myconfig{timeout}){
+		$timeout = "1 day";
+	} else {
+		$timeout = "$myconfig{timeout} seconds";
+	}
+
+	$checkQuery->execute($sessionid, $token, $timeout) || $form->dberror('Looking for session: ');
+	my $sessionValid = $checkQuery->rows;
+
+	if($sessionValid){
+
+		#user has a valid session cookie, now check the user
+		my ($sessionLogin) = $checkQuery->fetchrow_array;
+
+		my $login = $form->{login};
+		$login =~ s/[^a-zA-Z0-9@.-]//g;
+
+		if($sessionLogin eq $login){
+			$updateAge->execute($sessionid) || $form->dberror('Updating session age: ');
+			return 1;
+
+		} else {
+			#something's wrong, they have the cookie, but wrong user. Hijack attempt?
+			#delete the cookie in the browser
+			print qq|Set-Cookie: LedgerSMB=; path=/;\n|;
+			return 0;
+		}
+	
+	} else {
+		#cookie is not valid
+		#delete the cookie in the browser
+		print qq|Set-Cookie: LedgerSMB=; path=/;\n|;
+		print qq|Set-Cookie: DiedHere=true; path=/;\n|;
+		return 0;
+	}
+}
+
+sub session_create {
+	my ($form, %myconfig) = @_;
+
+	# connect to database
+	my $dbh = DBI->connect($myconfig{dbconnect}, $myconfig{dbuser}, $myconfig{dbpasswd});
+
+	# TODO Change this to use %myconfig
+	my $deleteExisting = $dbh->prepare("DELETE FROM session WHERE sl_login = ? AND age(last_used) > ?::interval");  
+
+	my $seedRandom = $dbh->prepare("SELECT setseed(?);");
+
+	my $fetchSequence = $dbh->prepare("SELECT nextval('session_session_id_seq'), md5(random());");
+	
+	my $createNew = $dbh->prepare("INSERT INTO session (session_id, sl_login, token) VALUES(?, ?, ?);");
+
+
+	# this is assuming that $form->{login} is safe, which might be a bad assumption
+	# so, I'm going to remove some chars, which might make previously valid logins invalid
+	my $login = $form->{login};
+	$login =~ s/[^a-zA-Z0-9@.-]//g;
+
+	#delete any existing stale sessions with this login if they exist
+	if (!$myconfig{timeout}){
+	   $myconfig{timeout} = 86400;
+	}
+
+	$deleteExisting->execute($login, "$myconfig{timeout} seconds") || $form->dberror('Delete from session: ');
+
+	#doing the md5 and random stuff in the db so that LedgerSMB won't
+	#require new perl modules (Digest::MD5 and a good random generator)
+	$fetchSequence->execute() || $form->dberror('Fetch sequence id: ');
+	my ($newSessionID, $newToken) = $fetchSequence->fetchrow_array;
+
+	#create a new session
+	$createNew->execute($newSessionID, $login, $newToken) || $form->dberror('Create new session: ');
+
+	#reseed the random number generator
+	my $randomSeed = 1.0 * ('0.'. (time() ^ ($$ + ($$ <<15))));
+	$seedRandom->execute($randomSeed)|| $form->dberror('Reseed random generator: ');;
+
+	$newCookieValue = $newSessionID . ':' . $newToken;
+
+	#now set the cookie in the browser
+	#TODO set domain from ENV, also set path to install path
+	print qq|Set-Cookie: LedgerSMB=$newCookieValue; path=/;\n|;
+	$form->{LedgerSMB} = $newCookieValue;
+}
+
+sub session_destroy {
+
+	# Under the current architecture, this function is a bit problematic
+	# %myconfig is often not defined when this function needs to be called.
+	# which means that the db connection parameters are not available.
+	# moving user prefs and the session table into a central db will solve this issue
+
+	my ($form, %myconfig) = @_;
+
+	my $login = $form->{login};
+	$login =~ s/[^a-zA-Z0-9@.-]//g;
+
+	# connect to database
+	my $dbh = DBI->connect($myconfig{dbconnect}, $myconfig{dbuser}, $myconfig{dbpasswd});
+
+	my $deleteExisting = $dbh->prepare("DELETE FROM session WHERE sl_login = ?;");
+	$deleteExisting->execute($login) || $form->dberror('Delete from session: ');
+
+	#delete the cookie in the browser
+	print qq|Set-Cookie: LedgerSMB=; path=/;\n|;
+
+}
+
+1;