Net.Pkcs11Interop.LowLevelAPI40.Pkcs11.C_DigestInit C# (CSharp) Method

        public CKR C_DigestInit(uint session, ref CK_MECHANISM mechanism)
        {
            if (this._disposed)
                throw new ObjectDisposedException(this.GetType().FullName);

            uint rv = _delegates.C_DigestInit(session, ref mechanism);
            return (CKR)rv;
        }

        public void _01_DigestSinglePartTest()
        {
            if (Platform.UnmanagedLongSize != 4 || Platform.StructPackingSize != 0)
                Assert.Inconclusive("Test cannot be executed on this platform");

            CKR rv = CKR.CKR_OK;
            
            using (Pkcs11 pkcs11 = new Pkcs11(Settings.Pkcs11LibraryPath))
            {
                rv = pkcs11.C_Initialize(Settings.InitArgs40);
                if ((rv != CKR.CKR_OK) && (rv != CKR.CKR_CRYPTOKI_ALREADY_INITIALIZED))
                    Assert.Fail(rv.ToString());
                
                // Find first slot with token present
                uint slotId = Helpers.GetUsableSlot(pkcs11);
                
                uint session = CK.CK_INVALID_HANDLE;
                rv = pkcs11.C_OpenSession(slotId, (CKF.CKF_SERIAL_SESSION | CKF.CKF_RW_SESSION), IntPtr.Zero, IntPtr.Zero, ref session);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                // Specify digesting mechanism (needs no parameter => no unamanaged memory is needed)
                CK_MECHANISM mechanism = CkmUtils.CreateMechanism(CKM.CKM_SHA_1);

                // Initialize digesting operation
                rv = pkcs11.C_DigestInit(session, ref mechanism);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                byte[] sourceData = ConvertUtils.Utf8StringToBytes("Hello world");

                // Get length of digest value in first call
                uint digestLen = 0;
                rv = pkcs11.C_Digest(session, sourceData, Convert.ToUInt32(sourceData.Length), null, ref digestLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                Assert.IsTrue(digestLen > 0);
                
                // Allocate array for digest value
                byte[] digest = new byte[digestLen];

                // Get digest value in second call
                rv = pkcs11.C_Digest(session, sourceData, Convert.ToUInt32(sourceData.Length), digest, ref digestLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                // Do something interesting with digest value
                
                rv = pkcs11.C_CloseSession(session);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                rv = pkcs11.C_Finalize(IntPtr.Zero);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
            }
        }