ParagonIE_Sodium_File::secretbox_decrypt_core32() protected WP 1.0
Decrypt a file (32-bit)
{} It's a method of the class: ParagonIE_Sodium_File{}
No Hooks.
Return
true|false
. Null. Nothing.
Usage
$result = ParagonIE_Sodium_File::secretbox_decrypt_core32( $ifp, $ofp, $mlen, $nonce, $key );
- $ifp(resource) (required)
- -
- $ofp(resource) (required)
- -
- $mlen(int) (required)
- -
- $nonce(string) (required)
- -
- $key(string) (required)
- -
Code of ParagonIE_Sodium_File::secretbox_decrypt_core32() ParagonIE Sodium File::secretbox decrypt core32 WP 5.7
protected static function secretbox_decrypt_core32($ifp, $ofp, $mlen, $nonce, $key)
{
$tag = fread($ifp, 16);
if (!is_string($tag)) {
throw new SodiumException('Could not read input file');
}
/** @var string $subkey */
$subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);
/** @var string $realNonce */
$realNonce = ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
/** @var string $block0 */
$block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20(
64,
ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
$subkey
);
/* Verify the Poly1305 MAC -before- attempting to decrypt! */
$state = new ParagonIE_Sodium_Core32_Poly1305_State(self::substr($block0, 0, 32));
if (!self::onetimeauth_verify_core32($state, $ifp, $tag, $mlen)) {
throw new SodiumException('Invalid MAC');
}
/*
* Set the cursor to the end of the first half-block. All future bytes will
* generated from salsa20_xor_ic, starting from 1 (second block).
*/
$first32 = fread($ifp, 32);
if (!is_string($first32)) {
throw new SodiumException('Could not read input file');
}
$first32len = self::strlen($first32);
fwrite(
$ofp,
self::xorStrings(
self::substr($block0, 32, $first32len),
self::substr($first32, 0, $first32len)
)
);
$mlen -= 32;
/** @var int $iter */
$iter = 1;
/** @var int $incr */
$incr = self::BUFFER_SIZE >> 6;
/* Decrypts ciphertext, writes to output file. */
while ($mlen > 0) {
$blockSize = $mlen > self::BUFFER_SIZE
? self::BUFFER_SIZE
: $mlen;
$ciphertext = fread($ifp, $blockSize);
if (!is_string($ciphertext)) {
throw new SodiumException('Could not read input file');
}
$pBlock = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(
$ciphertext,
$realNonce,
$iter,
$subkey
);
fwrite($ofp, $pBlock, $blockSize);
$mlen -= $blockSize;
$iter += $incr;
}
return true;
}