php_library/fboprime/sid.inc

<?php
//$Header: /hl/cvsroots/gpl01/gpl01/webprojs/fboprime/sw/phplib/sid.inc,v 1.3 2006/04/08 07:14:16 dashley Exp $
//********************************************************************************
//Copyright (C) 2006 David T. Ashley
//********************************************************************************
//This program or source file is free software; you can redistribute it and/or 
//modify it under the terms of the GNU General Public License as published by
//the Free Software Foundation; either version 2 of the License, or (at your 
//option) any later version.
//
//This program or source file is distributed in the hope that it will 
//be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU General Public License for more details.
//
//You may have received a copy of the GNU General Public License
//along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//********************************************************************************
//Dave Ashley, 04/06
//
//This source file provides the code to create and manipulate session
//identifiers (SIDs).  The format of the SGUID is documented in the 
//FBO-Prime manual.
//
require_once("sguid.inc");       //Necesssary to generate SGUIDs.
require_once("crhsh.inc");
//
//
//--------------------------------------------------------------------------------
//Returns a complete SID (including the "SI" prefix).
//
function SID_sid()
   {
   return("SI" . SID_sid_raw());
   }
//
//
//--------------------------------------------------------------------------------
//Returns a raw SID (without the "SI" prefix).
//
function SID_sid_raw()
   {
   $sguid  = SGUID_sguid();
   $crhash = CRHSH_hashva($sguid);

   //Convert any lower-case letters in the hash to upper-case.  This is canonical form.
   $crhash = StrToUpper($crhash);

   return($sguid . $crhash);
   }
//
//
//--------------------------------------------------------------------------------
//Returns the length of a SID (in characters).
//
function SID_sid_len()
   {
   return(66);
   }
//
//
//--------------------------------------------------------------------------------
//Validates the syntactic form of a SID.  Returns 0 if it isn't
//valid or 1 if it is.  Note that this validates only the form and the
//hash--the server session state aspect is not validated.
//
function SID_is_syntactically_valid($sid_to_check)
   {
   //Must be a string.
   if (! is_string($sid_to_check))
      return(0);

   //Must be of the right length.
   if (strlen($sid_to_check) != 66)
      return(0);

   //First two characters must be "SI".
   if (substr($sid_to_check, 0, 2) !== "SI")
      return(0);

   //The encapsulated SGUID must be valid.
   if (! SGUID_is_syntactically_valid(SubStr($sid_to_check, 2, 32)))
      return(0);

   //Generate a hash to match against.
   $original_hash   = SubStr($sid_to_check, 34, 32);
   $comparison_hash = StrToUpper(CRHSH_hashva(SubStr($sid_to_check, 2, 32)));

   //Compare the hashes.  Note that we don't have to check the string to be sure
   //hash chars are digits and hexadecimal digits--the comparison indirectly does
   //that for us.
   if ($original_hash != $comparison_hash)
      return(0);

   //If we're here, nothing obvious wrong with it.
   return(1);
   }
//--------------------------------------------------------------------------------
?>
1	<?php
2	//$Header: /hl/cvsroots/gpl01/gpl01/webprojs/fboprime/sw/phplib/sid.inc,v 1.3 2006/04/08 07:14:16 dashley Exp $
3	//********************************************************************************
4	//Copyright (C) 2006 David T. Ashley
5	//********************************************************************************
6	//This program or source file is free software; you can redistribute it and/or
7	//modify it under the terms of the GNU General Public License as published by
8	//the Free Software Foundation; either version 2 of the License, or (at your
9	//option) any later version.
10	//
11	//This program or source file is distributed in the hope that it will
12	//be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
13	//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	//GNU General Public License for more details.
15	//
16	//You may have received a copy of the GNU General Public License
17	//along with this program; if not, write to the Free Software
18	//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19	//********************************************************************************
20	//Dave Ashley, 04/06
21	//
22	//This source file provides the code to create and manipulate session
23	//identifiers (SIDs). The format of the SGUID is documented in the
24	//FBO-Prime manual.
25	//
26	require_once("sguid.inc"); //Necesssary to generate SGUIDs.
27	require_once("crhsh.inc");
28	//
29	//
30	//--------------------------------------------------------------------------------
31	//Returns a complete SID (including the "SI" prefix).
32	//
33	function SID_sid()
34	{
35	return("SI" . SID_sid_raw());
36	}
37	//
38	//
39	//--------------------------------------------------------------------------------
40	//Returns a raw SID (without the "SI" prefix).
41	//
42	function SID_sid_raw()
43	{
44	$sguid = SGUID_sguid();
45	$crhash = CRHSH_hashva($sguid);
46
47	//Convert any lower-case letters in the hash to upper-case. This is canonical form.
48	$crhash = StrToUpper($crhash);
49
50	return($sguid . $crhash);
51	}
52	//
53	//
54	//--------------------------------------------------------------------------------
55	//Returns the length of a SID (in characters).
56	//
57	function SID_sid_len()
58	{
59	return(66);
60	}
61	//
62	//
63	//--------------------------------------------------------------------------------
64	//Validates the syntactic form of a SID. Returns 0 if it isn't
65	//valid or 1 if it is. Note that this validates only the form and the
66	//hash--the server session state aspect is not validated.
67	//
68	function SID_is_syntactically_valid($sid_to_check)
69	{
70	//Must be a string.
71	if (! is_string($sid_to_check))
72	return(0);
73
74	//Must be of the right length.
75	if (strlen($sid_to_check) != 66)
76	return(0);
77
78	//First two characters must be "SI".
79	if (substr($sid_to_check, 0, 2) !== "SI")
80	return(0);
81
82	//The encapsulated SGUID must be valid.
83	if (! SGUID_is_syntactically_valid(SubStr($sid_to_check, 2, 32)))
84	return(0);
85
86	//Generate a hash to match against.
87	$original_hash = SubStr($sid_to_check, 34, 32);
88	$comparison_hash = StrToUpper(CRHSH_hashva(SubStr($sid_to_check, 2, 32)));
89
90	//Compare the hashes. Note that we don't have to check the string to be sure
91	//hash chars are digits and hexadecimal digits--the comparison indirectly does
92	//that for us.
93	if ($original_hash != $comparison_hash)
94	return(0);
95
96	//If we're here, nothing obvious wrong with it.
97	return(1);
98	}
99	//--------------------------------------------------------------------------------
100	?>