php - intermittent openssl_decrypt error (IV of precisely 16 bytes)
one text
I am receiving the following error when on decrypting certain data.
openssl_decrypt(): IV passed is only 12 bytes long, cipher expects an IV of precisely 16 bytes
I am also seeing the warning: hash_equals(): Expected known_string to be a string, boolean given.. perhaps some corrupted data.
I recently decrypted from mcrypt and re-encrypted with openssl (this code). I see I should be passing OPENSSL_RAW_DATA
here is my class:
class AES{
function __construct() {
$this->aes_256_cbc = 'aes-256-cbc';
}
function __destruct() {}
function encrypt($data,$passphrase){
$iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length($this->aes_256_cbc));
$dataEncrRaw = openssl_encrypt($data, $this->aes_256_cbc, $passphrase, 0, $iv);
$hmac = hash_hmac('sha256', $dataEncrRaw, $passphrase, $as_binary=true);
return base64_encode( $iv.$hmac.$dataEncrRaw );
}
function decrypt($dataEncr,$passphrase){
$data = '';
$dataEncr = base64_decode($dataEncr);
$ivlen = openssl_cipher_iv_length($cipher=$this->aes_256_cbc);
$iv=substr($dataEncr,0,$ivlen);
$hmac = substr($dataEncr, $ivlen, $sha2len=32);
$dataEncrRaw=substr($dataEncr,$ivlen+$sha2len);
$dataPlainText = openssl_decrypt($dataEncrRaw, $this->aes_256_cbc, $passphrase, 0, $iv);
$calcmac = hash_hmac('sha256', $dataEncrRaw, $passphrase, $as_binary=true);
if (hash_equals($hmac, $calcmac)){
$data=$dataPlainText;
}
return $data;
}
}
Thanks, Drew
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