function Decrypt($data, $pos, $opt = array())
{
/** @var cURL $cc */
$auth = "";
$baseUrl = "";
$cc = null;
extract($opt, EXTR_IF_EXISTS);
$debug = $this->debug;
if ($this->decryptorTest) {
$debug = false;
}
LogDebug("\n----- Akamai Decryption Start -----", $debug);
// Parse packet header
$byte = ReadByte($data, $pos++);
$this->ecmVersion = $byte >> 4;
if ($this->ecmVersion != 11) {
$this->ecmVersion = $byte;
}
$this->ecmID = ReadInt32($data, $pos);
$this->ecmTimestamp = ReadInt32($data, $pos + 4);
$this->kdfVersion = ReadInt16($data, $pos + 8);
$pos += 10;
$this->dccAccReserved = ReadByte($data, $pos++);
LogDebug("ECM Version : " . $this->ecmVersion . ", ECM ID: " . $this->ecmID . ", ECM Timestamp: " . $this->ecmTimestamp . ", KDF Version: " . $this->kdfVersion . ", DccAccReserved: " . $this->dccAccReserved, $debug);
$byte = ReadByte($data, $pos++);
$iv = ($byte & 2) > 0 ? true : false;
$key = ($byte & 4) > 0 ? true : false;
if ($iv) {
$this->packetIV = substr($data, $pos, 16);
$pos += 16;
LogDebug("PacketIV : " . hexlify($this->packetIV), $debug);
}
if ($key) {
$this->sessionKeyUrl = ReadString($data, $pos);
LogDebug("SessionKeyUrl: " . $this->sessionKeyUrl, $debug);
$keyUrl = substr($this->sessionKeyUrl, strrpos($this->sessionKeyUrl, '/'));
$this->sessionID = "_" . substr($keyUrl, strlen("/key_"));
$keyUrl = JoinUrl($baseUrl, $keyUrl) . $auth;
// Download key file if required
if ($this->sessionKeyUrl !== $this->lastKeyUrl) {
if ($baseUrl == "") {
LogDebug("Unable to download session key without manifest url. you must specify it manually using 'adkey' switch.", $debug);
} else {
if ($cc->get($keyUrl) != 200) {
LogError("Failed to download akamai session decryption key");
}
$this->sessionKey = $cc->response;
LogInfo("SessionKey: " . hexlify($this->sessionKey), $debug);
$this->lastKeyUrl = $this->sessionKeyUrl;
}
}
}
LogDebug("SessionKey : " . hexlify($this->sessionKey), $debug);
$reserved = ReadByte($data, $pos++);
$this->packetSalt = substr($data, $pos, 32);
$pos += 32;
$reservedBlock1 = substr($data, $pos, 20);
$reservedBlock2 = substr($data, $pos + 20, 20);
$pos += 40;
LogDebug("ReservedByte : " . $reserved . ", ReservedBlock1: " . hexlify($reservedBlock1) . ", ReservedBlock2: " . hexlify($reservedBlock2), $debug);
// Generate packet decryption key
if ($this->sessionKey == "") {
LogError("Fragments can't be decrypted properly without corresponding session key.", 2);
}
$this->KDF();
// Decrypt packet data
$encryptedData = substr($data, $pos);
LogDebug("EncryptedData: " . hexlify(substr($encryptedData, 0, 64)), $debug);
$lastBlockData = substr($encryptedData, $this->decryptBytes);
$encryptedData = substr($encryptedData, 0, $this->decryptBytes);
$decryptedData = "";
if ($this->decryptBytes > 0) {
mcrypt_generic_init($this->aes_cbc, $this->packetKey, $this->packetIV);
$decryptedData = mdecrypt_generic($this->aes_cbc, $encryptedData);
mcrypt_generic_deinit($this->aes_cbc);
}
$decryptedData .= $lastBlockData;
LogDebug("DecryptedData: " . hexlify(substr($decryptedData, 0, 64)), $debug);
LogDebug("----- Akamai Decryption End -----\n", $debug);
return $decryptedData;
}
$file = false;
if (file_exists($beatFile)) {
$file = file_get_contents($beatFile);
}
if ($file === false) {
LogError("Failed to open input file");
}
$fileLen = filesize($beatFile);
$filePos = 0;
$fileSize = $fileLen / (1024 * 1024);
$pFilePos = 0;
// Parse beat file header
$flags = ReadByte($file, 0);
$quality = $flags & 15;
$version = $flags >> 4;
$lookupSize = ReadInt16($file, 1);
$encTable = substr($file, 3, $lookupSize);
$filePos = $filePos + 3 + $lookupSize;
LogDebug("Version: {$version}, Quality: {$quality}, LookupSize: {$lookupSize}");
// Retrieve encryption key and iv
$key = "";
$iv = "";
for ($i = 0; $i < 32; $i += 2) {
$key .= $file[$filePos + $i];
$iv .= $file[$filePos + $i + 1];
}
$filePos += 32;
LogDebug("Key: " . hexlify($key));
LogDebug("IV : " . hexlify($iv));
// Decrypt lookup table
$td = mcrypt_module_open('rijndael-128', '', 'cbc', '');
