Net.Pkcs11Interop.HighLevelAPI81.Session.Sign C# (CSharp) Method

        public byte[] Sign(Mechanism mechanism, ObjectHandle keyHandle, Stream inputStream, int bufferLength)
        {
            if (this._disposed)
                throw new ObjectDisposedException(this.GetType().FullName);

            if (mechanism == null)
                throw new ArgumentNullException("mechanism");
            
            if (keyHandle == null)
                throw new ArgumentNullException("keyHandle");
            
            if (inputStream == null)
                throw new ArgumentNullException("inputStream");

            if (bufferLength < 1)
                throw new ArgumentException("Value has to be positive number", "bufferLength");

            CK_MECHANISM ckMechanism = mechanism.CkMechanism;

            CKR rv = _p11.C_SignInit(_sessionId, ref ckMechanism, keyHandle.ObjectId);
            if (rv != CKR.CKR_OK)
                throw new Pkcs11Exception("C_SignInit", rv);

            byte[] part = new byte[bufferLength];
            int bytesRead = 0;

            while ((bytesRead = inputStream.Read(part, 0, part.Length)) > 0)
            {
                rv = _p11.C_SignUpdate(_sessionId, part, Convert.ToUInt64(bytesRead));
                if (rv != CKR.CKR_OK)
                    throw new Pkcs11Exception("C_SignUpdate", rv);
            }

            ulong signatureLen = 0;
            rv = _p11.C_SignFinal(_sessionId, null, ref signatureLen);
            if (rv != CKR.CKR_OK)
                throw new Pkcs11Exception("C_SignFinal", rv);

            byte[] signature = new byte[signatureLen];
            rv = _p11.C_SignFinal(_sessionId, signature, ref signatureLen);
            if (rv != CKR.CKR_OK)
                throw new Pkcs11Exception("C_SignFinal", rv);

            if (signature.Length != Convert.ToInt32(signatureLen))
                Array.Resize(ref signature, Convert.ToInt32(signatureLen));

            return signature;
        }