Online PHP editor | output for Lk2qT

<?php # --- ENCRYPTION --- # the key should be random binary, use scrypt, bcrypt or PBKDF2 to # convert a string into a key # key is specified using hexadecimal $key = pack('H*', "bcb04b7e103a0cd8b54763051cef08bc55abe029f"); # show key size use either 16, 24 or 32 byte keys for AES-128, 192 # and 256 respectively $key_size = strlen($key); echo "Key size: " . $key_size . "\n"; $plaintext = "This string was AES-256 / CBC / ZeroBytePadding encrypted."; # create a random IV to use with CBC encoding $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC); $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); # creates a cipher text compatible with AES (Rijndael block size = 128) # to keep the text confidential # only suitable for encoded input that never ends with value 00h # (because of default zero padding) $ciphertext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $plaintext, MCRYPT_MODE_CBC, $iv); # prepend the IV for it to be available for decryption $ciphertext = $iv . $ciphertext; # encode the resulting cipher text so it can be represented by a string $ciphertext_base64 = base64_encode($ciphertext); echo $ciphertext_base64 . "\n"; # === WARNING === # Resulting cipher text has no integrity or authenticity added # and is not protected against padding oracle attacks. # --- DECRYPTION --- $ciphertext_dec = base64_decode($ciphertext_base64); # retrieves the IV, iv_size should be created using mcrypt_get_iv_size() $iv_dec = substr($ciphertext_dec, 0, $iv_size); # retrieves the cipher text (everything except the $iv_size in the front) $ciphertext_dec = substr($ciphertext_dec, $iv_size); # may remove 00h valued characters from end of plain text $plaintext_dec = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $ciphertext_dec, MCRYPT_MODE_CBC, $iv_dec); echo $plaintext_dec . "\n"; ?>