C_VerifyRecover() public method

Verifies a signature in a single-part operation, where the data is recovered from the signature
public C_VerifyRecover ( uint session, byte signature, uint signatureLen, byte data, uint &dataLen ) : CKR
session uint The session's handle
signature byte Signature
signatureLen uint The length of signature
data byte /// If set to null then the length of recovered data is returned in "dataLen" parameter, without actually returning recovered data. /// If not set to null then "dataLen" parameter must contain the lenght of data array and recovered data is returned in "data" parameter. ///
dataLen uint Location that holds the length of the decrypted data
return CKR
        public void _01_BasicSignAndVerifyRecoverTest()
        {
            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 signing mechanism (needs no parameter => no unamanaged memory is needed)
                CK_MECHANISM mechanism = CkmUtils.CreateMechanism(CKM.CKM_RSA_PKCS);
                
                // Initialize signing operation
                rv = pkcs11.C_SignRecoverInit(session, ref mechanism, privKeyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                byte[] sourceData = ConvertUtils.Utf8StringToBytes("Hello world");
                
                // Get length of signature in first call
                uint signatureLen = 0;
                rv = pkcs11.C_SignRecover(session, sourceData, Convert.ToUInt32(sourceData.Length), null, ref signatureLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                Assert.IsTrue(signatureLen > 0);
                
                // Allocate array for signature
                byte[] signature = new byte[signatureLen];
                
                // Get signature in second call
                rv = pkcs11.C_SignRecover(session, sourceData, Convert.ToUInt32(sourceData.Length), signature, ref signatureLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());
                
                // Do something interesting with signature
                
                // Initialize verification operation
                rv = pkcs11.C_VerifyRecoverInit(session, ref mechanism, pubKeyId);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                // Get length of recovered data in first call
                uint recoveredDataLen = 0;
                rv = pkcs11.C_VerifyRecover(session, signature, Convert.ToUInt32(signature.Length), null, ref recoveredDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                Assert.IsTrue(recoveredDataLen > 0);
                
                // Allocate array for recovered data
                byte[] recoveredData = new byte[recoveredDataLen];

                // Verify signature and get recovered data in second call
                rv = pkcs11.C_VerifyRecover(session, signature, Convert.ToUInt32(signature.Length), recoveredData, ref recoveredDataLen);
                if (rv != CKR.CKR_OK)
                    Assert.Fail(rv.ToString());

                // Do something interesting with verification result and recovered data
                Assert.IsTrue(Convert.ToBase64String(sourceData) == Convert.ToBase64String(recoveredData));

                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());
            }
        }