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DES: move IP/inverse IP transforms out of the round loop in inline_crypt_setup().

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This is another 20% runtime gain on triple DES.
This commit is contained in:
Patrick Monnerat 2013-05-21 16:01:10 +02:00
parent 448be87e83
commit f596c577cf
1 changed files with 47 additions and 40 deletions
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87
phpseclib/Crypt/DES.php
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@ -2125,63 +2125,70 @@ class Crypt_DES {
';
$_cryptBlock = '$in = unpack("N*", $in);'."\n";
// Do the initial IP permutation.
$_cryptBlock .= '
$l = $in[1];
$r = $in[2];
$in = unpack("N*",
($shuffle[$ipmap[ $r & 0xFF]] & "\x80\x80\x80\x80\x80\x80\x80\x80") |
($shuffle[$ipmap[($r >> 8) & 0xFF]] & "\x40\x40\x40\x40\x40\x40\x40\x40") |
($shuffle[$ipmap[($r >> 16) & 0xFF]] & "\x20\x20\x20\x20\x20\x20\x20\x20") |
($shuffle[$ipmap[($r >> 24) & 0xFF]] & "\x10\x10\x10\x10\x10\x10\x10\x10") |
($shuffle[$ipmap[ $l & 0xFF]] & "\x08\x08\x08\x08\x08\x08\x08\x08") |
($shuffle[$ipmap[($l >> 8) & 0xFF]] & "\x04\x04\x04\x04\x04\x04\x04\x04") |
($shuffle[$ipmap[($l >> 16) & 0xFF]] & "\x02\x02\x02\x02\x02\x02\x02\x02") |
($shuffle[$ipmap[($l >> 24) & 0xFF]] & "\x01\x01\x01\x01\x01\x01\x01\x01")
);
'.'' /* Extract L0 and R0 */ .'
$l = $in[1];
$r = $in[2];
';
$l = 'l';
$r = 'r';
for ($des_round = 0; $des_round < $des_rounds; ++$des_round) {
// Do the initial IP permutation.
$_cryptBlock .= '
$l = $in[1];
$r = $in[2];
$in = unpack("N*",
($shuffle[$ipmap[ $r & 0xFF]] & "\x80\x80\x80\x80\x80\x80\x80\x80") |
($shuffle[$ipmap[($r >> 8) & 0xFF]] & "\x40\x40\x40\x40\x40\x40\x40\x40") |
($shuffle[$ipmap[($r >> 16) & 0xFF]] & "\x20\x20\x20\x20\x20\x20\x20\x20") |
($shuffle[$ipmap[($r >> 24) & 0xFF]] & "\x10\x10\x10\x10\x10\x10\x10\x10") |
($shuffle[$ipmap[ $l & 0xFF]] & "\x08\x08\x08\x08\x08\x08\x08\x08") |
($shuffle[$ipmap[($l >> 8) & 0xFF]] & "\x04\x04\x04\x04\x04\x04\x04\x04") |
($shuffle[$ipmap[($l >> 16) & 0xFF]] & "\x02\x02\x02\x02\x02\x02\x02\x02") |
($shuffle[$ipmap[($l >> 24) & 0xFF]] & "\x01\x01\x01\x01\x01\x01\x01\x01")
);
'.'' /* Extract L0 and R0 */ .'
$l = $in[1];
$r = $in[2];
';
// Perform the 16 steps.
// start of "the Feistel (F) function" - see the following URL:
// http://en.wikipedia.org/wiki/Image:Data_Encryption_Standard_InfoBox_Diagram.png
// Merge key schedule.
for ($i = 0; $i < 8; ++$i) {
$_cryptBlock .= '
$b1 = (($r >> 3) & 0x1FFFFFFF) ^ ($r << 29) ^ $k_'.(++$ki).';
$b2 = (($r >> 31) & 0x00000001) ^ ($r << 1) ^ $k_'.(++$ki).';
$l = $sbox1[($b1 >> 24) & 0x3F] ^ $sbox2[($b2 >> 24) & 0x3F] ^
$b1 = (($' . $r . ' >> 3) & 0x1FFFFFFF) ^ ($' . $r . ' << 29) ^ $k_'.(++$ki).';
$b2 = (($' . $r . ' >> 31) & 0x00000001) ^ ($' . $r . ' << 1) ^ $k_'.(++$ki).';
$' . $l . ' = $sbox1[($b1 >> 24) & 0x3F] ^ $sbox2[($b2 >> 24) & 0x3F] ^
$sbox3[($b1 >> 16) & 0x3F] ^ $sbox4[($b2 >> 16) & 0x3F] ^
$sbox5[($b1 >> 8) & 0x3F] ^ $sbox6[($b2 >> 8) & 0x3F] ^
$sbox7[ $b1 & 0x3F] ^ $sbox8[ $b2 & 0x3F] ^ $l;
$sbox7[ $b1 & 0x3F] ^ $sbox8[ $b2 & 0x3F] ^ $' . $l . ';
$b1 = (($l >> 3) & 0x1FFFFFFF) ^ ($l << 29) ^ $k_'.(++$ki).';
$b2 = (($l >> 31) & 0x00000001) ^ ($l << 1) ^ $k_'.(++$ki).';
$r = $sbox1[($b1 >> 24) & 0x3F] ^ $sbox2[($b2 >> 24) & 0x3F] ^
$b1 = (($' . $l . ' >> 3) & 0x1FFFFFFF) ^ ($' . $l . ' << 29) ^ $k_'.(++$ki).';
$b2 = (($' . $l . ' >> 31) & 0x00000001) ^ ($' . $l . ' << 1) ^ $k_'.(++$ki).';
$' . $r . ' = $sbox1[($b1 >> 24) & 0x3F] ^ $sbox2[($b2 >> 24) & 0x3F] ^
$sbox3[($b1 >> 16) & 0x3F] ^ $sbox4[($b2 >> 16) & 0x3F] ^
$sbox5[($b1 >> 8) & 0x3F] ^ $sbox6[($b2 >> 8) & 0x3F] ^
$sbox7[ $b1 & 0x3F] ^ $sbox8[ $b2 & 0x3F] ^ $r;
$sbox7[ $b1 & 0x3F] ^ $sbox8[ $b2 & 0x3F] ^ $' . $r . ';
';
}
// Perform the inverse IP permutation.
$_cryptBlock .= '$in = ' . ($des_round == $des_rounds-1 ? '(' : 'unpack("N*",') . '
($shuffle[$invipmap[($l >> 24) & 0xFF]] & "\x80\x80\x80\x80\x80\x80\x80\x80") |
($shuffle[$invipmap[($r >> 24) & 0xFF]] & "\x40\x40\x40\x40\x40\x40\x40\x40") |
($shuffle[$invipmap[($l >> 16) & 0xFF]] & "\x20\x20\x20\x20\x20\x20\x20\x20") |
($shuffle[$invipmap[($r >> 16) & 0xFF]] & "\x10\x10\x10\x10\x10\x10\x10\x10") |
($shuffle[$invipmap[($l >> 8) & 0xFF]] & "\x08\x08\x08\x08\x08\x08\x08\x08") |
($shuffle[$invipmap[($r >> 8) & 0xFF]] & "\x04\x04\x04\x04\x04\x04\x04\x04") |
($shuffle[$invipmap[ $l & 0xFF]] & "\x02\x02\x02\x02\x02\x02\x02\x02") |
($shuffle[$invipmap[ $r & 0xFF]] & "\x01\x01\x01\x01\x01\x01\x01\x01")
);
';
// Last step should not permute L & R.
$t = $l;
$l = $r;
$r = $t;
}
// Perform the inverse IP permutation.
$_cryptBlock .= '$in = (
($shuffle[$invipmap[($' . $r . ' >> 24) & 0xFF]] & "\x80\x80\x80\x80\x80\x80\x80\x80") |
($shuffle[$invipmap[($' . $l . ' >> 24) & 0xFF]] & "\x40\x40\x40\x40\x40\x40\x40\x40") |
($shuffle[$invipmap[($' . $r . ' >> 16) & 0xFF]] & "\x20\x20\x20\x20\x20\x20\x20\x20") |
($shuffle[$invipmap[($' . $l . ' >> 16) & 0xFF]] & "\x10\x10\x10\x10\x10\x10\x10\x10") |
($shuffle[$invipmap[($' . $r . ' >> 8) & 0xFF]] & "\x08\x08\x08\x08\x08\x08\x08\x08") |
($shuffle[$invipmap[($' . $l . ' >> 8) & 0xFF]] & "\x04\x04\x04\x04\x04\x04\x04\x04") |
($shuffle[$invipmap[ $' . $r . ' & 0xFF]] & "\x02\x02\x02\x02\x02\x02\x02\x02") |
($shuffle[$invipmap[ $' . $l . ' & 0xFF]] & "\x01\x01\x01\x01\x01\x01\x01\x01")
);
';
// Generating mode of operation code:
switch ($mode) {
case CRYPT_DES_MODE_ECB: