C_Decrypt() public method

Decrypts encrypted data in a single part
public C_Decrypt ( uint session, byte encryptedData, uint encryptedDataLen, byte data, uint &dataLen ) : CKR
session uint The session's handle
encryptedData byte Encrypted data
encryptedDataLen uint The length of the encrypted data
data byte /// If set to null then the length of decrypted data is returned in "dataLen" parameter, without actually returning decrypted data. /// If not set to null then "dataLen" parameter must contain the lenght of data array and decrypted data is returned in "data" parameter. ///
dataLen uint Location that holds the length of the decrypted data
return CKR
        public void _01_EncryptAndDecryptSinglePartTest()
        {
            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());
                
                // Login as normal user
                rv = pkcs11.C_Login(session, CKU.CKU_USER, Settings.NormalUserPinArray, Convert.ToUInt32(Settings.NormalUserPinArray.Length));
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                // Generate symetric key
                uint keyId = CK.CK_INVALID_HANDLE;
                rv = Helpers.GenerateKey(pkcs11, session, ref keyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                // Generate random initialization vector
                byte[] iv = new byte[8];
                rv = pkcs11.C_GenerateRandom(session, iv, Convert.ToUInt32(iv.Length));
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                // Specify encryption mechanism with initialization vector as parameter.
                // Note that CkmUtils.CreateMechanism() automaticaly copies iv into newly allocated unmanaged memory.
                CK_MECHANISM mechanism = CkmUtils.CreateMechanism(CKM.CKM_DES3_CBC, iv);
                
                // Initialize encryption operation
                rv = pkcs11.C_EncryptInit(session, ref mechanism, keyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                byte[] sourceData = ConvertUtils.Utf8StringToBytes("Our new password");

                // Get length of encrypted data in first call
                uint encryptedDataLen = 0;
                rv = pkcs11.C_Encrypt(session, sourceData, Convert.ToUInt32(sourceData.Length), null, ref encryptedDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                Assert.IsTrue(encryptedDataLen > 0);

                // Allocate array for encrypted data
                byte[] encryptedData = new byte[encryptedDataLen];

                // Get encrypted data in second call
                rv = pkcs11.C_Encrypt(session, sourceData, Convert.ToUInt32(sourceData.Length), encryptedData, ref encryptedDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                // Do something interesting with encrypted data

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

                // Get length of decrypted data in first call
                uint decryptedDataLen = 0;
                rv = pkcs11.C_Decrypt(session, encryptedData, Convert.ToUInt32(encryptedData.Length), null, ref decryptedDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                Assert.IsTrue(decryptedDataLen > 0);
                
                // Allocate array for decrypted data
                byte[] decryptedData = new byte[decryptedDataLen];

                // Get decrypted data in second call
                rv = pkcs11.C_Decrypt(session, encryptedData, Convert.ToUInt32(encryptedData.Length), decryptedData, ref decryptedDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                // Do something interesting with decrypted data
                Assert.IsTrue(Convert.ToBase64String(sourceData) == Convert.ToBase64String(decryptedData));

                // In LowLevelAPI we have to free unmanaged memory taken by mechanism parameter (iv in this case)
                UnmanagedMemory.Free(ref mechanism.Parameter);
                mechanism.ParameterLen = 0;

                rv = pkcs11.C_DestroyObject(session, keyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                rv = pkcs11.C_Logout(session);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                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());
            }
        }
        public void _03_EncryptAndDecryptSinglePartOaepTest()
        {
            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());
                
                // Login as normal user
                rv = pkcs11.C_Login(session, CKU.CKU_USER, Settings.NormalUserPinArray, Convert.ToUInt32(Settings.NormalUserPinArray.Length));
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                // Generate asymetric key pair
                uint pubKeyId = CK.CK_INVALID_HANDLE;
                uint privKeyId = CK.CK_INVALID_HANDLE;
                rv = Helpers.GenerateKeyPair(pkcs11, session, ref pubKeyId, ref privKeyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                // Specify mechanism parameters
                CK_RSA_PKCS_OAEP_PARAMS mechanismParams = new CK_RSA_PKCS_OAEP_PARAMS();
                mechanismParams.HashAlg = (uint)CKM.CKM_SHA_1;
                mechanismParams.Mgf = (uint)CKG.CKG_MGF1_SHA1;
                mechanismParams.Source = (uint)CKZ.CKZ_DATA_SPECIFIED;
                mechanismParams.SourceData = IntPtr.Zero;
                mechanismParams.SourceDataLen = 0;
                
                // Specify encryption mechanism with parameters
                // Note that CkmUtils.CreateMechanism() automaticaly copies mechanismParams into newly allocated unmanaged memory.
                CK_MECHANISM mechanism = CkmUtils.CreateMechanism(CKM.CKM_RSA_PKCS_OAEP, mechanismParams);
                
                // Initialize encryption operation
                rv = pkcs11.C_EncryptInit(session, ref mechanism, pubKeyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                byte[] sourceData = ConvertUtils.Utf8StringToBytes("Hello world");
                
                // Get length of encrypted data in first call
                uint encryptedDataLen = 0;
                rv = pkcs11.C_Encrypt(session, sourceData, Convert.ToUInt32(sourceData.Length), null, ref encryptedDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                Assert.IsTrue(encryptedDataLen > 0);
                
                // Allocate array for encrypted data
                byte[] encryptedData = new byte[encryptedDataLen];
                
                // Get encrypted data in second call
                rv = pkcs11.C_Encrypt(session, sourceData, Convert.ToUInt32(sourceData.Length), encryptedData, ref encryptedDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                // Do something interesting with encrypted data
                
                // Initialize decryption operation
                rv = pkcs11.C_DecryptInit(session, ref mechanism, privKeyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                // Get length of decrypted data in first call
                uint decryptedDataLen = 0;
                rv = pkcs11.C_Decrypt(session, encryptedData, Convert.ToUInt32(encryptedData.Length), null, ref decryptedDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                Assert.IsTrue(decryptedDataLen > 0);
                
                // Allocate array for decrypted data
                byte[] decryptedData = new byte[decryptedDataLen];
                
                // Get decrypted data in second call
                rv = pkcs11.C_Decrypt(session, encryptedData, Convert.ToUInt32(encryptedData.Length), decryptedData, ref decryptedDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                // Array may need to be shrinked
                if (decryptedData.Length != decryptedDataLen)
                    Array.Resize(ref decryptedData, Convert.ToInt32(decryptedDataLen));

                // Do something interesting with decrypted data
                Assert.IsTrue(Convert.ToBase64String(sourceData) == Convert.ToBase64String(decryptedData));

                // In LowLevelAPI we have to free unmanaged memory taken by mechanism parameter
                UnmanagedMemory.Free(ref mechanism.Parameter);
                mechanism.ParameterLen = 0;
                
                rv = pkcs11.C_DestroyObject(session, privKeyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                rv = pkcs11.C_DestroyObject(session, pubKeyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                rv = pkcs11.C_Logout(session);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                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());
            }
        }