javascript - Encrypt in JavaSscript with NaCl, Decrypt With PHP libsodium using KeyPair

i want to use NaCl library in the client side and libsodium in php to encrypt/decrypt messages between the client and the server using keypair(public,private).

When i encrypt with libsodium and decrypt with NaCl everything works, But when i try to encrypt with NaCl and decrypt with libsodium i get no result.

Encrypting with NaCl in the client side

var message = "Sample Message";
var bytes = nacl.util.decodeUTF8(message);

var client_public = nacl.util.hex2bytearray('35e9f8477b60f61747722698d98791c4e0818ff75da3943a30e13dc0a457d402');
var client_private = nacl.util.hex2bytearray('6382cd5ef713375b6fe3835a763c72dfdc7ddcade7b8bcb9640065582708ef2c');
var server_public = nacl.util.hex2bytearray('1f348bac3b60d3076fc1a32d4e205df67356a9ef16d4b3f391c0e4817f3b987f');

var sharedkey = nacl.box.before(server_public, client_private);
var nonce = nacl.util.hex2bytearray('c031122a5f57e253686d9f6082d1061a1546e5567290c7f0'); // 24 bytes

var cipher = nacl.box.after(bytes, nonce, sharedkey );
var cihper_with_nonce = nacl.util.bytearray2hex(nonce) + bytearray2hex(cipher); // will be sent to the server
//c031122a5f57e253686d9f6082d1061a1546e5567290c7f0b2c05c9fb1483fe9b1bd2d4ae261832a54569748dd7925511b3d236e23e8
Copy code

nacl.util.hex2bytearray = hexString => new Uint8Array(hexString.match(/.{1,2}/g).map(byte => parseInt(byte, 16)));
nacl.util.bytearray2hex = bytes => bytes.reduce((str, byte) => str + byte.toString(16).padStart(2, '0'), '');
nacl.util.decodeUTF8=function(e){;var n,r=unescape(encodeURIComponent(e)),t=new Uint8Array(r.length);for(n=0;n<r.length;n++)t[n]=r.charCodeAt(n);return t}
Copy code

Decrypting with libsodium in PHP

$cihper_with_nonce = 'c031122a5f57e253686d9f6082d1061a1546e5567290c7f0b2c05c9fb1483fe9b1bd2d4ae261832a54569748dd7925511b3d236e23e8';// received from the client
$server_public = hex2bin('1f348bac3b60d3076fc1a32d4e205df67356a9ef16d4b3f391c0e4817f3b987f');// generated with libsodium
$server_private = hex2bin('cea48d3c14bc9ad26bf3f62932db5d7336b8212866c14dec64670f295ec89d5d');// generated with libsodium
$client_public = hex2bin('35e9f8477b60f61747722698d98791c4e0818ff75da3943a30e13dc0a457d402');// generated with NaCl

$sharedkey = sodium_crypto_box_keypair_from_secretkey_and_publickey($server_private, $client_public );

$nonce = hex2bin(substr($cihper_with_nonce, 0, 48));//24 bytes
$cihper = hex2bin(substr($cihper_with_nonce, 48));

$message = sodium_crypto_box_open($cihper , $nonce, $sharedkey );
var_dump($message);// bool(false)
Copy code

Am i using the Library the Wrong way or there is something i am doing it wrong?

Because when i encrypt with php and decrypt with NaCl everything works and i did the same way in reverse for the Decryption.

all the bytes(hex) used are generated with the same library.
NaCl Source nacl util
libsodium Source libsodium

Didn't find the answer?

Our community is visited by hundreds of web development professionals every day. Ask your question and get a quick answer for free.