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CS adjustments to petrich's code and optimizations

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terrafrost 2013-01-05 17:55:30 -06:00
parent fba455dfb2
commit 1626c0a3c7
1 changed files with 77 additions and 67 deletions
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144
phpseclib/Crypt/Rijndael.php
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@ -763,38 +763,46 @@ class Crypt_Rijndael {
}
break;
case CRYPT_RIJNDAEL_MODE_CFB:
$iv = $this->encryptIV;
$pos = $this->continuousBuffer === true ? $buffer['pos'] : 0;
$len = strlen($plaintext);
for ($i=0; $pos && $len; --$len, ++$i)
{
$iv[$pos] = $iv[$pos] ^ $plaintext[$i];
$ciphertext .= $iv[$pos];
$pos = ($pos+1) % $block_size;
}
for (; $len >= $block_size; $len-=$block_size, $i+=$block_size)
{
$iv = $this->_encryptBlock($iv) ^ substr($plaintext, $i, $block_size);
$ciphertext .= $iv;
}
if ($len)
{
$iv = $this->_encryptBlock($iv);
while ($len--)
{
$iv[$pos] = $iv[$pos] ^ $plaintext[$i];
$ciphertext .= $iv[$pos];
++$i;
++$pos;
}
}
if($this->continuousBuffer)
{
$this->encryptIV = $iv;
$buffer['pos'] = $pos;
// cfb loosely routines inspired by openssl's:
// http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1
$iv = $this->encryptIV;
$pos = $this->continuousBuffer === true ? $buffer['pos'] : 0;
$len = strlen($plaintext);
if ($pos) {
$orig_pos = $pos;
$max = $block_size - $pos;
if ($len >= $max) {
$i = $max;
$len-= $max;
$pos = 0;
} else {
$i = $len;
$pos+= $len;
$len = 0;
}
// ie. $i = min($max, $len), $len-= $i, $pos+= $i
$ciphertext = substr($iv, $orig_pos) ^ $plaintext;
$iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
}
while ($len >= $block_size) {
$iv = $this->_encryptBlock($iv) ^ substr($plaintext, $i, $block_size);
$ciphertext.= $iv;
$len-= $block_size;
$i+= $block_size;
}
if ($len) {
$iv = $this->_encryptBlock($iv);
//$block = substr($iv, $pos, $len) ^ substr($plaintext, $i, $len);
$block = substr($iv, $pos) ^ substr($plaintext, $i);
$iv = substr_replace($iv, $block, $pos, $len);
$ciphertext.= $block;
$i+= $len;
$pos+= $len;
}
if($this->continuousBuffer) {
$this->encryptIV = $iv;
$buffer['pos'] = $pos;
}
break;
case CRYPT_RIJNDAEL_MODE_OFB:
$xor = $this->encryptIV;
@ -888,43 +896,45 @@ class Crypt_Rijndael {
}
break;
case CRYPT_RIJNDAEL_MODE_CFB:
$iv = $this->decryptIV;
$pos = $this->continuousBuffer === true ? $buffer['pos'] : 0;
$len = strlen($ciphertext);
$iv = $this->decryptIV;
$pos = $this->continuousBuffer === true ? $buffer['pos'] : 0;
$len = strlen($ciphertext);
// cfb routines inspired by: http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1
for ($i=0; $pos && $len; --$len, ++$i)
{
$plaintext .= $iv[$pos] ^ $ciphertext[$i];
$iv[$pos] = $ciphertext[$i];
$pos = ($pos+1) % $block_size;
}
for (; $len >= $block_size; $len-=$block_size, $i+=$block_size)
{
$iv = $this->_encryptBlock($iv);
$cb = substr($ciphertext, $i, $block_size);
$plaintext .= $iv ^ $cb;
$iv = $cb;
}
if ($len)
{
$iv = $this->_encryptBlock($iv);
while ($len--)
{
$plaintext .= $iv[$pos] ^ $ciphertext[$i];
$iv[$pos] = $ciphertext[$i];
++$i;
++$pos;
}
}
if ($this->continuousBuffer)
{
$this->decryptIV = $iv;
$buffer['pos'] = $pos;
if ($pos) {
$orig_pos = $pos;
$max = $block_size - $pos;
if ($len >= $max) {
$i = $max;
$len-= $max;
$pos = 0;
} else {
$i = $len;
$pos+= $len;
$len = 0;
}
// ie. $i = min($max, $len), $len-= $i, $pos+= $i
$plaintext = substr($iv, $orig_pos) ^ $ciphertext;
$iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
}
while ($len >= $block_size) {
$iv = $this->_encryptBlock($iv);
$cb = substr($ciphertext, $i, $block_size);
$plaintext.= $iv ^ $cb;
$iv = $cb;
$len-= $block_size;
$i+= $block_size;
}
if ($len) {
$iv = $this->_encryptBlock($iv);
$plaintext.= substr($iv, $pos) ^ substr($ciphertext, $i);
$iv = substr_replace($iv, substr($ciphertext, $i, $len), $pos, $len);
$i+= $len;
$pos+= $len;
}
if ($this->continuousBuffer) {
$this->decryptIV = $iv;
$buffer['pos'] = $pos;
}
break;
case CRYPT_RIJNDAEL_MODE_OFB:
$xor = $this->decryptIV;
@ -1508,4 +1518,4 @@ class Crypt_Rijndael {
}
// vim: ts=4:sw=4:et:
// vim6: fdl=1:
// vim6: fdl=1: