Net.Pkcs11Interop.LowLevelAPI81.Pkcs11.C_DigestUpdate C# (CSharp) Method

        public CKR C_DigestUpdate(ulong session, byte[] part, ulong partLen)
        {
            if (this._disposed)
                throw new ObjectDisposedException(this.GetType().FullName);

            ulong rv = _delegates.C_DigestUpdate(session, part, partLen);
            return (CKR)Convert.ToUInt32(rv);
        }

        public void _02_DigestMultiPartTest()
        {
            if (Platform.UnmanagedLongSize != 8 || Platform.StructPackingSize != 1)
                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.InitArgs81);
                if ((rv != CKR.CKR_OK) && (rv != CKR.CKR_CRYPTOKI_ALREADY_INITIALIZED))
                    Assert.Fail(rv.ToString());
                
                // Find first slot with token present
                ulong slotId = Helpers.GetUsableSlot(pkcs11);
                
                ulong 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);

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

                // Multipart digesting functions C_DigestUpdate and C_DigestFinal can be used i.e. for digesting of streamed data
                using (MemoryStream inputStream = new MemoryStream(sourceData))
                {
                    // Initialize digesting operation
                    rv = pkcs11.C_DigestInit(session, ref mechanism);
                    if (rv != CKR.CKR_OK)
                        Assert.Fail(rv.ToString());

                    // Prepare buffer for source data part
                    // Note that in real world application we would rather use bigger buffer i.e. 4096 bytes long
                    byte[] part = new byte[8];

                    // Read input stream with source data
                    int bytesRead = 0;
                    while ((bytesRead = inputStream.Read(part, 0, part.Length)) > 0)
                    {
                        // Digest each individual source data part
                        rv = pkcs11.C_DigestUpdate(session, part, Convert.ToUInt64(bytesRead));
                        if (rv != CKR.CKR_OK)
                            Assert.Fail(rv.ToString());
                    }

                    // Get length of digest value in first call
                    ulong digestLen = 0;
                    rv = pkcs11.C_DigestFinal(session, null, ref digestLen);
                    if (rv != CKR.CKR_OK)
                        Assert.Fail(rv.ToString());;

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

                    // Get digest value in second call
                    rv = pkcs11.C_DigestFinal(session, 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());
            }
        }