public static string BuildCanonicalString()

in sdk/Util/SignUtils.cs [45:94]
39 lines of code
11 McCabe index (conditional complexity)

        public static string BuildCanonicalString(string method, string resourcePath,
                                                  ServiceRequest request)
        {
            var canonicalString = new StringBuilder();
            
            canonicalString.Append(method).Append(NewLineMarker);

            var headers = request.Headers;
            IDictionary<string, string> headersToSign = new Dictionary<string, string>();
            if (headers != null)
            {
                foreach (var header in headers)
                {
                    var lowerKey = header.Key.ToLowerInvariant();

                    if (lowerKey == HttpHeaders.ContentType.ToLowerInvariant()
                        || lowerKey == HttpHeaders.ContentMd5.ToLowerInvariant()
                        || lowerKey == HttpHeaders.Date.ToLowerInvariant()
                        || lowerKey.StartsWith(OssHeaders.OssPrefix))
                    {
                        headersToSign.Add(lowerKey, header.Value);
                    }
                }
            }

            if (!headersToSign.ContainsKey(HttpHeaders.ContentType.ToLowerInvariant()))
                headersToSign.Add(HttpHeaders.ContentType.ToLowerInvariant(), "");
            if (!headersToSign.ContainsKey(HttpHeaders.ContentMd5.ToLowerInvariant()))
                headersToSign.Add(HttpHeaders.ContentMd5.ToLowerInvariant(), "");

            // Add all headers to sign into canonical string, 
            // note that these headers should be ordered before adding.
            var sortedHeaders = new List<string>(headersToSign.Keys);
            sortedHeaders.Sort(new KeyComparer());
            foreach (var key in sortedHeaders)
            {
                var value = headersToSign[key];
                if (key.StartsWith(OssHeaders.OssPrefix))
                    canonicalString.Append(key).Append(':').Append(value);
                else
                    canonicalString.Append(value);

                canonicalString.Append(NewLineMarker);
            }

            // Add canonical resource
            canonicalString.Append(BuildCanonicalizedResource(resourcePath, request.Parameters));

            return canonicalString.ToString();
        }