SIPSorcery.SIP.SIPAuthorisationDigest.ParseAuthorisationDigest C# (CSharp) Method

        public static SIPAuthorisationDigest ParseAuthorisationDigest(SIPAuthorisationHeadersEnum authorisationType, string authorisationRequest)
        {
            SIPAuthorisationDigest authRequest = new SIPAuthorisationDigest(authorisationType);

            string noDigestHeader = Regex.Replace(authorisationRequest, @"^\s*Digest\s*", "", RegexOptions.IgnoreCase);
            string[] headerFields = noDigestHeader.Split(',');

            if (headerFields != null && headerFields.Length > 0)
            {
                foreach (string headerField in headerFields)
                {
                    int equalsIndex = headerField.IndexOf('=');

                    if (equalsIndex != -1 && equalsIndex < headerField.Length)
                    {
                        string headerName = headerField.Substring(0, equalsIndex).Trim();
                        string headerValue = headerField.Substring(equalsIndex + 1).Trim(m_headerFieldRemoveChars);

                        if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_REALM_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            authRequest.Realm = headerValue;
                        }
                        else if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_NONCE_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            authRequest.Nonce = headerValue;
                        }
                        else if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_USERNAME_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            authRequest.Username = headerValue;
                        }
                        else if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_RESPONSE_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            authRequest.Response = headerValue;
                        }
                        else if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_URI_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            authRequest.URI = headerValue;
                        }
                        else if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_CNONCE_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            authRequest.Cnonce = headerValue;
                        }
                        else if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_NONCECOUNT_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            Int32.TryParse(headerValue, out authRequest.NonceCount);
                        }
                        else if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_QOP_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            authRequest.Qop = headerValue.ToLower();
                        }
                        else if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_OPAQUE_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            authRequest.Opaque = headerValue;
                        }
                        else if (Regex.Match(headerName, "^" + AuthHeaders.AUTH_ALGORITHM_KEY + "$", RegexOptions.IgnoreCase).Success)
                        {
                            authRequest.Algorithhm = headerValue;
                        }
                    }
                }
            }

            return authRequest;
        }