System.Net.SSPIWrapper.VerifySignature C# (CSharp) Method

        public static int VerifySignature(SSPIInterface secModule, SafeDeleteContext context, SecurityBuffer[] input, uint sequenceNumber)
        {
            return EncryptDecryptHelper(OP.VerifySignature, secModule, context, input, sequenceNumber);
        }

        internal int Decrypt(byte[] payload, int offset, int count, out int newOffset, uint expectedSeqNumber)
        {
            if (offset < 0 || offset > (payload == null ? 0 : payload.Length))
            {
                if (GlobalLog.IsEnabled)
                {
                    GlobalLog.Assert("NTAuthentication#" + LoggingHash.HashString(this) + "::Decrypt", "Argument 'offset' out of range.");
                }

                throw new ArgumentOutOfRangeException("offset");
            }

            if (count < 0 || count > (payload == null ? 0 : payload.Length - offset))
            {
                if (GlobalLog.IsEnabled)
                {
                    GlobalLog.Assert("NTAuthentication#" + LoggingHash.HashString(this) + "::Decrypt", "Argument 'count' out of range.");
                }

                throw new ArgumentOutOfRangeException("count");
            }

            if (IsNTLM)
            {
                return(DecryptNtlm(payload, offset, count, out newOffset, expectedSeqNumber));
            }

            //
            // Kerberos and up
            //
            var securityBuffer = new SecurityBuffer[2];

            securityBuffer[0] = new SecurityBuffer(payload, offset, count, SecurityBufferType.Stream);
            securityBuffer[1] = new SecurityBuffer(0, SecurityBufferType.Data);

            int errorCode;

            if (IsConfidentialityFlag)
            {
                errorCode = SSPIWrapper.DecryptMessage(GlobalSSPI.SSPIAuth, _securityContext, securityBuffer, expectedSeqNumber);
            }
            else
            {
                errorCode = SSPIWrapper.VerifySignature(GlobalSSPI.SSPIAuth, _securityContext, securityBuffer, expectedSeqNumber);
            }

            if (errorCode != 0)
            {
                GlobalLog.Print("NTAuthentication#" + LoggingHash.HashString(this) + "::Decrypt() throw Error = " + errorCode.ToString("x", NumberFormatInfo.InvariantInfo));
                throw new Win32Exception(errorCode);
            }

            if (securityBuffer[1].type != SecurityBufferType.Data)
            {
                throw new InternalException();
            }

            newOffset = securityBuffer[1].offset;
            return(securityBuffer[1].size);
        }