修复授权给第三方下载文件的url生成问题。

Author: cuiliang

src/OssClient.cs

@@ -236,19 +236,26 @@ public async Task<OssResult<GetObjectMetaResult>> GetObjectMetaAsync(BucketInfo
         /// <summary>
         /// 获取文件的下载链接
         /// </summary>
-        /// <param name="storeKey"></param>
-        /// <param name="expireSeconds"></param>
+        /// <param name="bucket">bucket信息</param>
+        /// <param name="storeKey">文件存储key</param>
+        /// <param name="expireSeconds">签名超时时间秒数</param>
+        /// <param name="imgStyle">阿里云图片处理样式</param>
         /// <returns></returns>
-        public string GetFileDownloadLink(BucketInfo bucket, string storeKey, int expireSeconds)
+        public string GetFileDownloadLink(BucketInfo bucket, string storeKey, int expireSeconds, string imgStyle = null)
         {
-            long seconds = (DateTime.UtcNow.Ticks - 621355968000000000) / 10000000;
+            long seconds = (DateTime.UtcNow.AddSeconds(expireSeconds).Ticks - 621355968000000000) / 10000000;
 
             string toSign = String.Format("GET\n\n\n{0}\n/{1}/{2}", seconds, bucket.BucketName, storeKey);
+            if (!String.IsNullOrEmpty(imgStyle))
+            {
+                toSign += $"?x-oss-process=style/{imgStyle}";
+            }
 
             string sign = ServiceSignature.Create().ComputeSignature(
-                _requestContext.OssCredential.AccessKeyId, toSign);
+                _requestContext.OssCredential.AccessKeySecret, toSign);
 
-            string url = $"{bucket.BucketUri}/{storeKey}?OSSAccessKeyId={_requestContext.OssCredential.AccessKeyId}&Expires={seconds}&Signature={WebUtility.UrlEncode(sign)}";
+            string styleSegment = String.IsNullOrEmpty(imgStyle) ? String.Empty : $"x-oss-process=style/{imgStyle}&";
+            string url = $"{bucket.BucketUri}{storeKey}?{styleSegment}OSSAccessKeyId={_requestContext.OssCredential.AccessKeyId}&Expires={seconds}&Signature={WebUtility.UrlEncode(sign)}";
 
             return url;
         }

src/Utility/Authentication/HmacSHA1Signature.cs

@@ -32,11 +32,17 @@ protected override string ComputeSignatureCore(string key, string data)
             //        algorithm.ComputeHash(_encoding.GetBytes(data.ToCharArray())));
             //}
 
-            using (var algorithm = new HMACSHA1(_encoding.GetBytes(key.ToCharArray())))
+            var bytes = _encoding.GetBytes(key);
+            Trace.WriteLine("Key:" + key + " Data:" + data);
+            Trace.WriteLine(bytes);
+
+            using (var algorithm = new HMACSHA1(_encoding.GetBytes(key)))
             {
                 //algorithm.Key = _encoding.GetBytes(key.ToCharArray());
-                return Convert.ToBase64String(
+                var result = Convert.ToBase64String(
                     algorithm.ComputeHash(_encoding.GetBytes(data.ToCharArray())));
+                Trace.WriteLine("Result:" + result);
+                return result;
             }
         }
     }