SyrupPayJose.Jwa.Alg.AesWrapEngine.Unwrap C# (CSharp) Méthode

        internal byte[] Unwrap(byte[] encryptedCek)
        {
            // 1) Initialize variables
            byte[][] c = Arrays.Slice(encryptedCek, 8);
            byte[] a = c[0];                           //   Set A = C[0]
            byte[][] r = new byte[c.Length - 1][];

            for (int i = 1; i < c.Length; i++)         //   For i = 1 to n
                r[i - 1] = c[i];                       //       R[i] = C[i]

            long n = r.Length;
            // 2) Calculate intermediate values
            for (long j = 5; j >= 0; j--)                                   // For j = 5 to 0
            {
                for (long i = n - 1; i >= 0; i--)                           //   For i = n to 1
                {
                    long t = n * j + i + 1;

                    a = Arrays.Xor(a, t);
                    byte[] B = AesDec(kek, Arrays.Concat(a, r[i]));     //     B = AES-1(K, (A ^ t) | R[i]) where t = n*j+i
                    a = Arrays.FirstHalf(B);                                  //     A = MSB(64, B)
                    r[i] = Arrays.SecondHalf(B);                              //     R[i] = LSB(64, B)
                }
            }

            // 3) Output the results
            if (!Arrays.ConstantTimeEquals(DefaultIV, a))   // If A is an appropriate initial value
                throw new InvalidSignatureException("AesKeyWrap integrity check failed.");

            // For i = 1 to n
            return Arrays.Concat(r);                        //    P[i] = R[i]
        }

 private byte[] UnWrap(byte[] key, byte[] src)
 {
     var engine = new AesWrapEngine();
     engine.Init(key);
     return engine.Unwrap(src);
 }