以下方法从文件和签名生成解析时间间隔中获得策略声明。
public static string CreatePolicyStatement(string policyStmnt,
string resourceUrl,
DateTime startTime,
DateTime endTime,
string ipAddress)
// Create the policy statement.
FileStream streamPolicy = new FileStream(policyStmnt, FileMode.Open, FileAccess.Read);
using (StreamReader reader = new StreamReader(streamPolicy))
string strPolicy = reader.ReadToEnd();
TimeSpan startTimeSpanFromNow = (startTime - DateTime.Now);
TimeSpan endTimeSpanFromNow = (endTime - DateTime.Now);
TimeSpan intervalStart =
(DateTime.UtcNow.Add(startTimeSpanFromNow)) -
new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
TimeSpan intervalEnd =
(DateTime.UtcNow.Add(endTimeSpanFromNow)) -
new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
int startTimestamp = (int)intervalStart.TotalSeconds; // START_TIME
int endTimestamp = (int)intervalEnd.TotalSeconds; // END_TIME
if (startTimestamp > endTimestamp)
return "Error!";
// Replace variables in the policy statement.
strPolicy = strPolicy.Replace("RESOURCE", resourceUrl);
strPolicy = strPolicy.Replace("START_TIME", startTimestamp.ToString());
strPolicy = strPolicy.Replace("END_TIME", endTimestamp.ToString());
strPolicy = strPolicy.Replace("IP_ADDRESS", ipAddress);
strPolicy = strPolicy.Replace("EXPIRES", endTimestamp.ToString());
return strPolicy;
public static TimeSpan GetDuration(string units, string numUnits)
TimeSpan timeSpanInterval = new TimeSpan();
switch (units)
case "seconds":
timeSpanInterval = new TimeSpan(0, 0, 0, int.Parse(numUnits));
break;
case "minutes":
timeSpanInterval = new TimeSpan(0, 0, int.Parse(numUnits), 0);
break;
case "hours":
timeSpanInterval = new TimeSpan(0, int.Parse(numUnits), 0 ,0);
break;
case "days":
timeSpanInterval = new TimeSpan(int.Parse(numUnits),0 ,0 ,0);
break;
default:
Console.WriteLine("Invalid time units;" +
"use seconds, minutes, hours, or days");
break;
return timeSpanInterval;
private static TimeSpan GetDurationByUnits(string durationUnits,
string startIntervalFromNow)
switch (durationUnits)
case "seconds":
return new TimeSpan(0, 0, int.Parse(startIntervalFromNow));
case "minutes":
return new TimeSpan(0, int.Parse(startIntervalFromNow), 0);
case "hours":
return new TimeSpan(int.Parse(startIntervalFromNow), 0, 0);
case "days":
return new TimeSpan(int.Parse(startIntervalFromNow), 0, 0, 0);
default:
return new TimeSpan(0, 0, 0, 0);
public static string CopyExpirationTimeFromPolicy(string policyStatement)
int startExpiration = policyStatement.IndexOf("EpochTime");
string strExpirationRough = policyStatement.Substring(startExpiration +
"EpochTime".Length);
char[] digits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
List<char> listDigits = new List<char>(digits);
StringBuilder buildExpiration = new StringBuilder(20);
foreach (char c in strExpirationRough)
if (listDigits.Contains(c))
buildExpiration.Append(c);
return buildExpiration.ToString();
}
