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

C_Digest() public method

Digests data in a single part
public C_Digest ( uint session, byte data, uint dataLen, byte digest, uint &digestLen ) : CKR
session uint The session's handle
data byte Data to be digested
dataLen uint The length of the data to be digested
digest byte /// If set to null then the length of digest is returned in "digestLen" parameter, without actually returning digest. /// If not set to null then "digestLen" parameter must contain the lenght of digest array and digest is returned in "digest" parameter. ///
digestLen uint Location that holds the length of the message digest
return CKR
        public CKR C_Digest(uint session, byte[] data, uint dataLen, byte[] digest, ref uint digestLen)
        {
            if (this._disposed)
                throw new ObjectDisposedException(this.GetType().FullName);

            uint rv = _delegates.C_Digest(session, data, dataLen, digest, ref digestLen);
            return (CKR)rv;
        }

Usage Example

        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());
            }
        }