SodiumException secretkey should be SODIUM_CRYPTO_SIGN_SECRETKEYBYTES bytes

Question

Trying to generate the secret key from the keypair and I get the exception: SodiumException secretkey should be SODIUM_CRYPTO_SIGN_SECRETKEYBYTES bytes See my code below

 if(file_exists($keypair)) {
    $keypair = file_get_contents($keypair, FALSE, NULL);

    dd(Keypair::fromSecretKey($keypair));
 }

After running this, I get that sodium exception.

  SodiumException

  secretkey should be SODIUM_CRYPTO_SIGN_SECRETKEYBYTES bytes

  at vendor/tightenco/solana-php-sdk/src/Keypair.php:73
     69▕     static public function fromSecretKey($secretKey): Keypair
     70▕     {
     71▕         $secretKey = Buffer::from($secretKey)->toString();
     72▕
  ➜  73▕         $publicKey = sodium_crypto_sign_publickey_from_secretkey($secretKey);
     74▕
     75▕         return new static(
     76▕             $publicKey,
     77▕             $secretKey

      +1 vendor frames
  2   app/Console/Commands/Initializer.php:81
      Tighten\SolanaPhpSdk\Keypair::fromSecretKey()

      +13 vendor frames
  16  artisan:37
      Illuminate\Foundation\Console\Kernel::handle()

Answer 1

Quite simple, just need to json_decode the keypair and pass an array to the fromSecretKey function:

  $keypair = file_get_contents($keypair, FALSE, NULL);

  dd(Keypair::fromSecretKey(json_decode($keypair)));