1
我在vbscript中有以下SHA256算法實現，我發現它here，我試圖將其轉換爲php。隨着一點點的谷歌搜索和運氣，我發現here在PHP中的實現。將SHA256算法從VBScript轉換爲PHP
這裏是的VBScript： （你可以從Windows CMD如運行它：test.vbs passwordtohash）
Private m_lOnBits(30)
Private m_l2Power(30)
Private K(63)
Private Const BITS_TO_A_BYTE = 8
Private Const BYTES_TO_A_WORD = 4
Private Const BITS_TO_A_WORD = 32
m_lOnBits(0) = CLng(1)
m_lOnBits(1) = CLng(3)
m_lOnBits(2) = CLng(7)
m_lOnBits(3) = CLng(15)
m_lOnBits(4) = CLng(31)
m_lOnBits(5) = CLng(63)
m_lOnBits(6) = CLng(127)
m_lOnBits(7) = CLng(255)
m_lOnBits(8) = CLng(511)
m_lOnBits(9) = CLng(1023)
m_lOnBits(10) = CLng(2047)
m_lOnBits(11) = CLng(4095)
m_lOnBits(12) = CLng(8191)
m_lOnBits(13) = CLng(16383)
m_lOnBits(14) = CLng(32767)
m_lOnBits(15) = CLng(65535)
m_lOnBits(16) = CLng(131071)
m_lOnBits(17) = CLng(262143)
m_lOnBits(18) = CLng(524287)
m_lOnBits(19) = CLng(1048575)
m_lOnBits(20) = CLng(2097151)
m_lOnBits(21) = CLng(4194303)
m_lOnBits(22) = CLng(8388607)
m_lOnBits(23) = CLng(16777215)
m_lOnBits(24) = CLng(33554431)
m_lOnBits(25) = CLng(67108863)
m_lOnBits(26) = CLng(134217727)
m_lOnBits(27) = CLng(268435455)
m_lOnBits(28) = CLng(536870911)
m_lOnBits(29) = CLng(1073741823)
m_lOnBits(30) = CLng(2147483647)
m_l2Power(0) = CLng(1)
m_l2Power(1) = CLng(2)
m_l2Power(2) = CLng(4)
m_l2Power(3) = CLng(8)
m_l2Power(4) = CLng(16)
m_l2Power(5) = CLng(32)
m_l2Power(6) = CLng(64)
m_l2Power(7) = CLng(128)
m_l2Power(8) = CLng(256)
m_l2Power(9) = CLng(512)
m_l2Power(10) = CLng(1024)
m_l2Power(11) = CLng(2048)
m_l2Power(12) = CLng(4096)
m_l2Power(13) = CLng(8192)
m_l2Power(14) = CLng(16384)
m_l2Power(15) = CLng(32768)
m_l2Power(16) = CLng(65536)
m_l2Power(17) = CLng(131072)
m_l2Power(18) = CLng(262144)
m_l2Power(19) = CLng(524288)
m_l2Power(20) = CLng(1048576)
m_l2Power(21) = CLng(2097152)
m_l2Power(22) = CLng(4194304)
m_l2Power(23) = CLng(8388608)
m_l2Power(24) = CLng(16777216)
m_l2Power(25) = CLng(33554432)
m_l2Power(26) = CLng(67108864)
m_l2Power(27) = CLng(134217728)
m_l2Power(28) = CLng(268435456)
m_l2Power(29) = CLng(536870912)
m_l2Power(30) = CLng(1073741824)
K(0) = &H428A2F98
K(1) = &H71374491
K(2) = &HB5C0FBCF
K(3) = &HE9B5DBA5
K(4) = &H3956C25B
K(5) = &H59F111F1
K(6) = &H923F82A4
K(7) = &HAB1C5ED5
K(8) = &HD807AA98
K(9) = &H12835B01
K(10) = &H243185BE
K(11) = &H550C7DC3
K(12) = &H72BE5D74
K(13) = &H80DEB1FE
K(14) = &H9BDC06A7
K(15) = &HC19BF174
K(16) = &HE49B69C1
K(17) = &HEFBE4786
K(18) = &HFC19DC6
K(19) = &H240CA1CC
K(20) = &H2DE92C6F
K(21) = &H4A7484AA
K(22) = &H5CB0A9DC
K(23) = &H76F988DA
K(24) = &H983E5152
K(25) = &HA831C66D
K(26) = &HB00327C8
K(27) = &HBF597FC7
K(28) = &HC6E00BF3
K(29) = &HD5A79147
K(30) = &H6CA6351
K(31) = &H14292967
K(32) = &H27B70A85
K(33) = &H2E1B2138
K(34) = &H4D2C6DFC
K(35) = &H53380D13
K(36) = &H650A7354
K(37) = &H766A0ABB
K(38) = &H81C2C92E
K(39) = &H92722C85
K(40) = &HA2BFE8A1
K(41) = &HA81A664B
K(42) = &HC24B8B70
K(43) = &HC76C51A3
K(44) = &HD192E819
K(45) = &HD6990624
K(46) = &HF40E3585
K(47) = &H106AA070
K(48) = &H19A4C116
K(49) = &H1E376C08
K(50) = &H2748774C
K(51) = &H34B0BCB5
K(52) = &H391C0CB3
K(53) = &H4ED8AA4A
K(54) = &H5B9CCA4F
K(55) = &H682E6FF3
K(56) = &H748F82EE
K(57) = &H78A5636F
K(58) = &H84C87814
K(59) = &H8CC70208
K(60) = &H90BEFFFA
K(61) = &HA4506CEB
K(62) = &HBEF9A3F7
K(63) = &HC67178F2
Private Function LShift(lValue, iShiftBits)
If iShiftBits = 0 Then
LShift = lValue
Exit Function
ElseIf iShiftBits = 31 Then
If lValue And 1 Then
LShift = &H80000000
Else
LShift = 0
End If
Exit Function
ElseIf iShiftBits < 0 Or iShiftBits > 31 Then
Err.Raise 6
End If
If (lValue And m_l2Power(31 - iShiftBits)) Then
LShift = ((lValue And m_lOnBits(31 - (iShiftBits + 1))) * m_l2Power(iShiftBits)) Or &H80000000
Else
LShift = ((lValue And m_lOnBits(31 - iShiftBits)) * m_l2Power(iShiftBits))
End If
End Function
Private Function RShift(lValue, iShiftBits)
If iShiftBits = 0 Then
RShift = lValue
Exit Function
ElseIf iShiftBits = 31 Then
If lValue And &H80000000 Then
RShift = 1
Else
RShift = 0
End If
Exit Function
ElseIf iShiftBits < 0 Or iShiftBits > 31 Then
Err.Raise 6
End If
RShift = (lValue And &H7FFFFFFE) \ m_l2Power(iShiftBits)
If (lValue And &H80000000) Then
RShift = (RShift Or (&H40000000 \ m_l2Power(iShiftBits - 1)))
End If
End Function
Private Function AddUnsigned(lX, lY)
Dim lX4
Dim lY4
Dim lX8
Dim lY8
Dim lResult
lX8 = lX And &H80000000
lY8 = lY And &H80000000
lX4 = lX And &H40000000
lY4 = lY And &H40000000
lResult = (lX And &H3FFFFFFF) + (lY And &H3FFFFFFF)
If lX4 And lY4 Then
lResult = lResult Xor &H80000000 Xor lX8 Xor lY8
ElseIf lX4 Or lY4 Then
If lResult And &H40000000 Then
lResult = lResult Xor &HC0000000 Xor lX8 Xor lY8
Else
lResult = lResult Xor &H40000000 Xor lX8 Xor lY8
End If
Else
lResult = lResult Xor lX8 Xor lY8
End If
AddUnsigned = lResult
End Function
Private Function Ch(x, y, z)
Ch = ((x And y) Xor ((Not x) And z))
End Function
Private Function Maj(x, y, z)
Maj = ((x And y) Xor (x And z) Xor (y And z))
End Function
Private Function S(x, n)
S = (RShift(x, (n And m_lOnBits(4))) Or LShift(x, (32 - (n And m_lOnBits(4)))))
End Function
Private Function R(x, n)
R = RShift(x, CInt(n And m_lOnBits(4)))
End Function
Private Function Sigma0(x)
Sigma0 = (S(x, 2) Xor S(x, 13) Xor S(x, 22))
End Function
Private Function Sigma1(x)
Sigma1 = (S(x, 6) Xor S(x, 11) Xor S(x, 25))
End Function
Private Function Gamma0(x)
Gamma0 = (S(x, 7) Xor S(x, 18) Xor R(x, 3))
End Function
Private Function Gamma1(x)
Gamma1 = (S(x, 17) Xor S(x, 19) Xor R(x, 10))
End Function
Private Function ConvertToWordArray(sMessage)
Dim lMessageLength
Dim lNumberOfWords
Dim lWordArray()
Dim lBytePosition
Dim lByteCount
Dim lWordCount
Dim lByte
Const MODULUS_BITS = 512
Const CONGRUENT_BITS = 448
lMessageLength = Len(sMessage)
lNumberOfWords = (((lMessageLength + ((MODULUS_BITS - CONGRUENT_BITS) \ BITS_TO_A_BYTE)) \ (MODULUS_BITS \ BITS_TO_A_BYTE)) + 1) * (MODULUS_BITS \ BITS_TO_A_WORD)
ReDim lWordArray(lNumberOfWords - 1)
lBytePosition = 0
lByteCount = 0
Do Until lByteCount >= lMessageLength
lWordCount = lByteCount \ BYTES_TO_A_WORD
lBytePosition = (3 - (lByteCount Mod BYTES_TO_A_WORD)) * BITS_TO_A_BYTE
lByte = AscB(Mid(sMessage, lByteCount + 1, 1))
lWordArray(lWordCount) = lWordArray(lWordCount) Or LShift(lByte, lBytePosition)
lByteCount = lByteCount + 1
Loop
lWordCount = lByteCount \ BYTES_TO_A_WORD
lBytePosition = (3 - (lByteCount Mod BYTES_TO_A_WORD)) * BITS_TO_A_BYTE
lWordArray(lWordCount) = lWordArray(lWordCount) Or LShift(&H80, lBytePosition)
lWordArray(lNumberOfWords - 1) = LShift(lMessageLength, 3)
lWordArray(lNumberOfWords - 2) = RShift(lMessageLength, 29)
ConvertToWordArray = lWordArray
End Function
Public Function SHA256(sMessage)
Dim HASH(7)
Dim M
Dim W(63)
Dim a
Dim b
Dim c
Dim d
Dim e
Dim f
Dim g
Dim h
Dim i
Dim j
Dim T1
Dim T2
HASH(0) = &H6A09E667
HASH(1) = &HBB67AE85
HASH(2) = &H3C6EF372
HASH(3) = &HA54FF53A
HASH(4) = &H510E527F
HASH(5) = &H9B05688C
HASH(6) = &H1F83D9AB
HASH(7) = &H5BE0CD19
M = ConvertToWordArray(sMessage)
For i = 0 To UBound(M) Step 16
a = HASH(0)
b = HASH(1)
c = HASH(2)
d = HASH(3)
e = HASH(4)
f = HASH(5)
g = HASH(6)
h = HASH(7)
For j = 0 To 63
If j < 16 Then
W(j) = M(j + i)
Else
W(j) = AddUnsigned(AddUnsigned(AddUnsigned(Gamma1(W(j - 2)), W(j - 7)), Gamma0(W(j - 15))), W(j - 16))
End If
T1 = AddUnsigned(AddUnsigned(AddUnsigned(AddUnsigned(h, Sigma1(e)), Ch(e, f, g)), K(j)), W(j))
T2 = AddUnsigned(Sigma0(a), Maj(a, b, c))
h = g
g = f
f = e
e = AddUnsigned(d, T1)
d = c
c = b
b = a
a = AddUnsigned(T1, T2)
Next
HASH(0) = AddUnsigned(a, HASH(0))
HASH(1) = AddUnsigned(b, HASH(1))
HASH(2) = AddUnsigned(c, HASH(2))
HASH(3) = AddUnsigned(d, HASH(3))
HASH(4) = AddUnsigned(e, HASH(4))
HASH(5) = AddUnsigned(f, HASH(5))
HASH(6) = AddUnsigned(g, HASH(6))
HASH(7) = AddUnsigned(h, HASH(7))
Next
SHA256 = LCase(Right("00000000" & Hex(HASH(0)), 8) & Right("00000000" & Hex(HASH(1)), 8) & Right("00000000" & Hex(HASH(2)), 8) & Right("00000000" & Hex(HASH(3)), 8) & Right("00000000" & Hex(HASH(4)), 8) & Right("00000000" & Hex(HASH(5)), 8) & Right("00000000" & Hex(HASH(6)), 8) & Right("00000000" & Hex(HASH(7)), 8))
End Function
Set args = Wscript.Arguments
For Each arg In args
sDigest = SHA256(arg)
Wscript.Echo "#### "&sDigest
Next
這裏是phpSha.php文件：
<?php
class auth_sha256
{
/**
* On Bits for sha256 mapping
*
* @access private
* @var array
*/
private $m_lOnBits = array(1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535,131071,262143,524287,1048575,2097151,4194303,8388607,16777215,33554431,67108863,134217727,268435455,536870911,1073741823,2147483647);
/**
* 2nd power sha256 mapping
*
* @access private
* @var array
*/
private $m_l2Power = array(1,2,4,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,32768,65536,131072,262144,524288,1048576,2097152,4194304,8388608,16777216,33554432,67108864,134217728,268435456,536870912,1073741824);
/**
* Hex mapping sha256 mapping
*
* @access private
* @var array
*/
private $K = array(0x428A2F98,0x71374491,0xB5C0FBCF,0xE9B5DBA5,0x3956C25B,0x59F111F1,0x923F82A4,0xAB1C5ED5,0xD807AA98,0x12835B01,0x243185BE,0x550C7DC3,0x72BE5D74,0x80DEB1FE,0x9BDC06A7,0xC19BF174,0xE49B69C1,0xEFBE4786,0xFC19DC6,0x240CA1CC,0x2DE92C6F,0x4A7484AA,0x5CB0A9DC,0x76F988DA,0x983E5152,0xA831C66D,0xB00327C8,0xBF597FC7,0xC6E00BF3,0xD5A79147,0x6CA6351,0x14292967,0x27B70A85,0x2E1B2138,0x4D2C6DFC,0x53380D13,0x650A7354,0x766A0ABB,0x81C2C92E,0x92722C85,0xA2BFE8A1,0xA81A664B,0xC24B8B70,0xC76C51A3,0xD192E819,0xD6990624,0xF40E3585,0x106AA070,0x19A4C116,0x1E376C08,0x2748774C,0x34B0BCB5,0x391C0CB3,0x4ED8AA4A,0x5B9CCA4F,0x682E6FF3,0x748F82EE,0x78A5636F,0x84C87814,0x8CC70208,0x90BEFFFA,0xA4506CEB,0xBEF9A3F7,0xC67178F2);
/**
* Perform SHA256 encoding
*
* @access public
* @param string String to encode
* @return string Encoded string
*/
public function SHA256($sMessage)
{
$HASH = array(0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19);
$M = $this->ConvertToWordArray($sMessage);
for($i = 0, $ij = count($M); $i < $ij; $i+=16)
{
$a = $HASH[0];
$b = $HASH[1];
$c = $HASH[2];
$d = $HASH[3];
$e = $HASH[4];
$f = $HASH[5];
$g = $HASH[6];
$h = $HASH[7];
for($j = 0; $j<63; $j++)
{
if($j < 16)
{
$W[$j] = $M[$j + $i];
}
else
{
$W[$j] = $this->AddUnsigned($this->AddUnsigned($this->AddUnsigned($this->Gamma1($W[$j - 2]), $W[$j - 7]), $this->Gamma0($W[$j - 15])), $W[$j - 16]);
}
$T1 = $this->AddUnsigned($this->AddUnsigned($this->AddUnsigned($this->AddUnsigned($h, $this->Sigma1($e)), $this->Ch($e, $f, $g)), $this->K[$j]), $W[$j]);
$T2 = $this->AddUnsigned($this->Sigma0($a), $this->Maj($a, $b, $c));
$h = $g;
$g = $f;
$f = $e;
$e = $this->AddUnsigned($d, $T1);
$d = $c;
$c = $b;
$b = $a;
$a = $this->AddUnsigned($T1, $T2);
}
$HASH[0] = $this->AddUnsigned($a, $HASH[0]);
$HASH[1] = $this->AddUnsigned($b, $HASH[1]);
$HASH[2] = $this->AddUnsigned($c, $HASH[2]);
$HASH[3] = $this->AddUnsigned($d, $HASH[3]);
$HASH[4] = $this->AddUnsigned($e, $HASH[4]);
$HASH[5] = $this->AddUnsigned($f, $HASH[5]);
$HASH[6] = $this->AddUnsigned($g, $HASH[6]);
$HASH[7] = $this->AddUnsigned($h, $HASH[7]);
}
for ($i=0; $i < 8; $i++)
{
$HASH[$i] = str_repeat("0",8-strlen(dechex($HASH[$i]))) . strtolower(dechex($HASH[$i]));
}
return $HASH[0].$HASH[1].$HASH[2].$HASH[3].$HASH[4].$HASH[5].$HASH[6].$HASH[7];
}
/**
* Left shift a value x bits
*
* @access private
* @param string String to shift
* @param integer Number of bits to shift
* @return string Shifted string
*/
private function LShift($lValue, $iShiftBits)
{
if ($iShiftBits == 0)
{
return $lValue;
}
elseif ($iShiftBits == 31)
{
if ($lValue & 1)
{
return 0x80000000;
}
else
{
return 0;
}
}
elseif ($iShiftBits < 0 Or $iShiftBits > 31)
{
exit();
}
if ($lValue & $this->m_l2Power[31 - $iShiftBits])
{
return (($lValue & $this->m_lOnBits[31 - ($iShiftBits + 1)]) * $this->m_l2Power[$iShiftBits]) | 0x80000000;
}
else
{
return (($lValue & $this->m_lOnBits[31 - $iShiftBits]) * $this->m_l2Power[$iShiftBits]);
}
}
/**
* Right shift a value x bits
*
* @access private
* @param string String to shift
* @param integer Number of bits to shift
* @return string Shifted string
*/
private function RShift($lValue, $iShiftBits)
{
if ($iShiftBits == 0)
{
return $lValue;
}
elseif ($iShiftBits == 31)
{
if ($lValue & 0x80000000)
{
$RShift = 1;
}
else
{
$RShift = 0;
}
}
elseif ($iShiftBits < 0 Or $iShiftBits > 31)
{
exit();
}
$RShift = floor(($lValue & 0x7FFFFFFE)/$this->m_l2Power[$iShiftBits]);
if ($lValue & 0x80000000)
{
$RShift = ($RShift | floor(0x40000000/$this->m_l2Power[$iShiftBits - 1]));
}
return $RShift;
}
/**
* Add unsigned
*
* @access private
* @param integer Number
* @param integer Number
* @return string Added unsigned integer
*/
private function AddUnsigned($lX, $lY)
{
$lX8 = $lX & 0x80000000;
$lY8 = $lY & 0x80000000;
$lX4 = $lX & 0x40000000;
$lY4 = $lY & 0x40000000;
$lResult = ($lX & 0x3FFFFFFF) + ($lY & 0x3FFFFFFF);
if ($lX4 & $lY4)
{
$lResult = $lResult^0x80000000^$lX8^$lY8;
}
elseif ($lX4 | $lY4)
{
if ($lResult & 0x40000000)
{
$lResult = $lResult^0xC0000000^$lX8^$lY8;
}
else
{
$lResult = $lResult^0x40000000^$lX8^$lY8;
}
}
else
{
$lResult = $lResult^$lX8^$lY8;
}
return $lResult;
}
/**
* Ch
*
* @access private
* @param integer $x
* @param integer $y
* @param integer $z
* @return mixed No idea...
*/
private function Ch($x, $y, $z)
{
return (($x & $y)^((~ $x) & $z));
}
/**
* Maj
*
* @access private
* @param integer $x
* @param integer $y
* @param integer $z
* @return mixed No idea...
*/
private function Maj($x, $y, $z)
{
return (($x & $y)^($x & $z)^($y & $z));
}
/**
* S
*
* @access private
* @param integer $x
* @param integer $n
* @return mixed No idea...
*/
private function S($x, $n)
{
return ($this->RShift($x , ($n & $this->m_lOnBits[4])) | $this->LShift($x , (32 - ($n & $this->m_lOnBits[4]))));
}
/**
* R
*
* @access private
* @param integer $x
* @param integer $n
* @return mixed No idea...
*/
private function R($x, $n)
{
return $this->RShift($x , ($n & $this->m_lOnBits[4]));
}
/**
* Sigma0
*
* @access private
* @param integer $x
* @return mixed No idea...
*/
private function Sigma0($x)
{
return ($this->S($x, 2)^$this->S($x, 13)^$this->S($x, 22));
}
/**
* Sigma1
*
* @access private
* @param integer $x
* @return mixed No idea...
*/
private function Sigma1($x)
{
return ($this->S($x, 6)^$this->S($x, 11)^$this->S($x, 25));
}
/**
* Gamma0
*
* @access private
* @param integer $x
* @return mixed No idea...
*/
private function Gamma0($x)
{
return ($this->S($x, 7)^$this->S($x, 18)^$this->R($x, 3));
}
/**
* Gamma1
*
* @access private
* @param integer $x
* @return mixed No idea...
*/
private function Gamma1($x)
{
return ($this->S($x, 17)^$this->S($x, 19)^$this->R($x, 10));
}
/**
* Convert to a word array
*
* @access private
* @param string Word to convert
* @return array Word array
*/
private function ConvertToWordArray($sMessage)
{
$BITS_TO_A_BYTE = 8;
$BYTES_TO_A_WORD = 4;
$BITS_TO_A_WORD = 32;
$MODULUS_BITS = 512;
$CONGRUENT_BITS = 448;
$lMessageLength = strlen($sMessage);
$lNumberOfWords = (floor(($lMessageLength + floor(($MODULUS_BITS - $CONGRUENT_BITS)/$BITS_TO_A_BYTE))/floor($MODULUS_BITS/$BITS_TO_A_BYTE)) + 1) * floor($MODULUS_BITS/$BITS_TO_A_WORD);
for($i = 0; $i < $lNumberOfWords; $i++)
{
$lWordArray[$i]="";
}
$lBytePosition = 0;
$lByteCount = 0;
do
{
$lWordCount = floor($lByteCount/$BYTES_TO_A_WORD);
$lBytePosition = (3 - ($lByteCount % $BYTES_TO_A_WORD)) * $BITS_TO_A_BYTE;
$lByte = ord(substr($sMessage, $lByteCount, 1));
$lWordArray[$lWordCount] = $lWordArray[$lWordCount] | $this->LShift($lByte , $lBytePosition);
$lByteCount++;
}
while ($lByteCount < $lMessageLength);
$lWordCount = floor($lByteCount/$BYTES_TO_A_WORD);
$lBytePosition = (3 - ($lByteCount % $BYTES_TO_A_WORD)) * $BITS_TO_A_BYTE;
$lWordArray[$lWordCount] = $lWordArray[$lWordCount] | $this->LShift(0x80 , $lBytePosition);
$lWordArray[$lNumberOfWords - 1] = $this->LShift($lMessageLength , 3);
$lWordArray[$lNumberOfWords - 2] = $this->RShift($lMessageLength , 29);
return $lWordArray;
}
}
可以運行它與test.php文件：
<?php
require_once ('phpSha.php');
$sha = new auth_sha256();
$password = $sha->SHA256('hello');
echo $password;
?>
當我運行與密碼的VBScript你好SHA256哈希是2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824 ，結果爲字符串hello用php SHA256實現：0e52daf0a5e0f63d5cd8e0d63b667960d5b02c51ee85c243572ea4b636ea90c4 有人可以幫助我弄清楚什麼是錯的，哈希別比賽？
是的，你是對的它提供了相同的散列但VBScript實如果你改變了行對於j = 0到63，爲j = 0到47和線SHA256 = LCASE（右（「00000000」＆ 8）＆Right（「00000000」＆Hex（HASH（2）），8）＆Right（「00000000」＆Hex（HASH（1））， （HASH（5）），8）＆Right（「00000000」＆Hex（HASH（4）），8）＆Right（「00000000」 「＆Hex（HASH（6）），8）＆Right（」00000000「＆Hex（HASH（7）），8））從8到6，你可以有一個48字節的摘要，我嘗試用php 。 – fnkbz