CI_SHA Class Reference

List of all members.

Public Member Functions
	CI_SHA ()
	generate ($str)
	Generate the Hash.
	_hex ($str)
	Convert a decimal to hex.
	_ft ($t, $b, $c, $d)
	Return result based on iteration.
	_kt ($t)
	Determine the additive constant.
	_safe_add ($x, $y)
	Add integers, wrapping at 2^32.
	_rol ($num, $cnt)
	Bitwise rotate a 32-bit number.
	_zero_fill ($a, $b)
	Pad string with zero.

---

Detailed Description

Definition at line 45 of file Sha1.php.

---

Member Function Documentation

CI_SHA::_ft	(	$	t,
		$	b,
		$	c,
		$	d
	)

Return result based on iteration.

private

Returns:

string

Definition at line 150 of file Sha1.php.

Referenced by generate().

        {
                if ($t < 20)
                        return ($b & $c) | ((~$b) & $d);
                if ($t < 40)
                        return $b ^ $c ^ $d;
                if ($t < 60)
                        return ($b & $c) | ($b & $d) | ($c & $d);

                return $b ^ $c ^ $d;
        }

Here is the caller graph for this function:

CI_SHA::_hex

(

$

str

)

Convert a decimal to hex.

private

Parameters:

string

Returns:

string

Definition at line 130 of file Sha1.php.

Referenced by generate().

        {
                $str = dechex($str);

                if (strlen($str) == 7)
                {
                        $str = '0'.$str;
                }

                return $str;
        }

Here is the caller graph for this function:

CI_SHA::_kt

(

$

t

)

Determine the additive constant.

private

Returns:

string

Definition at line 170 of file Sha1.php.

Referenced by generate().

        {
                if ($t < 20)
                {
                        return 1518500249;
                }
                else if ($t < 40)
                {
                        return 1859775393;
                }
                else if ($t < 60)
                {
                        return -1894007588;
                }
                else
                {
                        return -899497514;
                }
        }

Here is the caller graph for this function:

CI_SHA::_rol	(	$	num,
		$	cnt
	)

Bitwise rotate a 32-bit number.

private

Returns:

integer

Definition at line 214 of file Sha1.php.

References _zero_fill().

Referenced by generate().

        {
                return ($num << $cnt) | $this->_zero_fill($num, 32 - $cnt);
        }

Here is the call graph for this function:

Here is the caller graph for this function:

CI_SHA::_safe_add	(	$	x,
		$	y
	)

Add integers, wrapping at 2^32.

private

Returns:

string

Definition at line 198 of file Sha1.php.

Referenced by generate().

        {
                $lsw = ($x & 0xFFFF) + ($y & 0xFFFF);
                $msw = ($x >> 16) + ($y >> 16) + ($lsw >> 16);

                return ($msw << 16) | ($lsw & 0xFFFF);
        }

Here is the caller graph for this function:

CI_SHA::_zero_fill	(	$	a,
		$	b
	)

Pad string with zero.

private

Returns:

string

Definition at line 227 of file Sha1.php.

Referenced by _rol().

        {
                $bin = decbin($a);

                if (strlen($bin) < $b)
                {
                        $bin = 0;
                }
                else
                {
                        $bin = substr($bin, 0, strlen($bin) - $b);
                }

                for ($i=0; $i < $b; $i++)
                {
                        $bin = "0".$bin;
                }

                return bindec($bin);
        }

Here is the caller graph for this function:

CI_SHA::CI_SHA

(

)

Definition at line 47 of file Sha1.php.

References log_message().

        {
                log_message('debug', "SHA1 Class Initialized");
        }

Here is the call graph for this function:

CI_SHA::generate

(

$

str

)

Generate the Hash.

public

Parameters:

string

Returns:

string

Definition at line 59 of file Sha1.php.

References _ft(), _hex(), _kt(), _rol(), and _safe_add().

        {
                $n = ((strlen($str) + 8) >> 6) + 1;

                for ($i = 0; $i < $n * 16; $i++)
                {
                        $x[$i] = 0;
                }

                for ($i = 0; $i < strlen($str); $i++)
                {
                        $x[$i >> 2] |= ord(substr($str, $i, 1)) << (24 - ($i % 4) * 8);
                }

                $x[$i >> 2] |= 0x80 << (24 - ($i % 4) * 8);

                $x[$n * 16 - 1] = strlen($str) * 8;

                $a =  1732584193;
                $b = -271733879;
                $c = -1732584194;
                $d =  271733878;
                $e = -1009589776;

                for ($i = 0; $i < sizeof($x); $i += 16)
                {
                        $olda = $a;
                        $oldb = $b;
                        $oldc = $c;
                        $oldd = $d;
                        $olde = $e;

                        for($j = 0; $j < 80; $j++)
                        {
                                if ($j < 16)
                                {
                                        $w[$j] = $x[$i + $j];
                                }
                                else
                                {
                                        $w[$j] = $this->_rol($w[$j - 3] ^ $w[$j - 8] ^ $w[$j - 14] ^ $w[$j - 16], 1);
                                }

                                $t = $this->_safe_add($this->_safe_add($this->_rol($a, 5), $this->_ft($j, $b, $c, $d)), $this->_safe_add($this->_safe_add($e, $w[$j]), $this->_kt($j)));

                                $e = $d;
                                $d = $c;
                                $c = $this->_rol($b, 30);
                                $b = $a;
                                $a = $t;
                        }

                        $a = $this->_safe_add($a, $olda);
                        $b = $this->_safe_add($b, $oldb);
                        $c = $this->_safe_add($c, $oldc);
                        $d = $this->_safe_add($d, $oldd);
                        $e = $this->_safe_add($e, $olde);
                }

                return $this->_hex($a).$this->_hex($b).$this->_hex($c).$this->_hex($d).$this->_hex($e);
        }

Here is the call graph for this function:

---

The documentation for this class was generated from the following file:

• Sha1.php