Initial Commit

iTechSharp/srcbc/asn1/DerGeneralizedTime.cs

@@ -0,0 +1,289 @@
+using System;
+using System.Globalization;
+using System.Text;
+
+namespace Org.BouncyCastle.Asn1
+{
+    /**
+     * Generalized time object.
+     */
+    public class DerGeneralizedTime
+        : Asn1Object
+    {
+        private readonly string time;
+
+		/**
+         * return a generalized time from the passed in object
+         *
+         * @exception ArgumentException if the object cannot be converted.
+         */
+        public static DerGeneralizedTime GetInstance(
+            object obj)
+        {
+			if (obj == null || obj is DerGeneralizedTime)
+            {
+                return (DerGeneralizedTime)obj;
+            }
+
+			if (obj is Asn1OctetString)
+            {
+                return new DerGeneralizedTime(((Asn1OctetString)obj).GetOctets());
+            }
+
+			throw new ArgumentException("illegal object in GetInstance: " + obj.GetType().Name, "obj");
+        }
+
+		/**
+         * return a Generalized Time object from a tagged object.
+         *
+         * @param obj the tagged object holding the object we want
+         * @param explicitly true if the object is meant to be explicitly
+         *              tagged false otherwise.
+         * @exception ArgumentException if the tagged object cannot
+         *               be converted.
+         */
+        public static DerGeneralizedTime GetInstance(
+            Asn1TaggedObject	obj,
+            bool				explicitly)
+        {
+            return GetInstance(obj.GetObject());
+        }
+
+		/**
+		 * The correct format for this is YYYYMMDDHHMMSS[.f]Z, or without the Z
+		 * for local time, or Z+-HHMM on the end, for difference between local
+		 * time and UTC time. The fractional second amount f must consist of at
+		 * least one number with trailing zeroes removed.
+		 *
+		 * @param time the time string.
+		 * @exception ArgumentException if string is an illegal format.
+		 */
+		public DerGeneralizedTime(
+			string time)
+		{
+			this.time = time;
+
+			try
+			{
+				ToDateTime();
+			}
+			catch (FormatException e)
+			{
+				throw new ArgumentException("invalid date string: " + e.Message);
+			}
+		}
+
+		/**
+         * base constructor from a local time object
+         */
+        public DerGeneralizedTime(
+            DateTime time)
+        {
+            this.time = time.ToString(@"yyyyMMddHHmmss\Z");
+        }
+
+		internal DerGeneralizedTime(
+            byte[] bytes)
+        {
+            //
+            // explicitly convert to characters
+            //
+			this.time = Encoding.ASCII.GetString(bytes, 0, bytes.Length);
+        }
+
+		/**
+		 * Return the time.
+		 * @return The time string as it appeared in the encoded object.
+		 */
+		public string TimeString
+		{
+			get { return time; }
+		}
+
+		/**
+         * return the time - always in the form of
+         *  YYYYMMDDhhmmssGMT(+hh:mm|-hh:mm).
+         * <p>
+         * Normally in a certificate we would expect "Z" rather than "GMT",
+         * however adding the "GMT" means we can just use:
+         * <pre>
+         *     dateF = new SimpleDateFormat("yyyyMMddHHmmssz");
+         * </pre>
+         * To read in the time and Get a date which is compatible with our local
+         * time zone.</p>
+         */
+        public string GetTime()
+        {
+            //
+            // standardise the format.
+            //
+            if (time[time.Length - 1] == 'Z')
+            {
+                return time.Substring(0, time.Length - 1) + "GMT+00:00";
+            }
+            else
+            {
+                int signPos = time.Length - 5;
+                char sign = time[signPos];
+                if (sign == '-' || sign == '+')
+                {
+                    return time.Substring(0, signPos)
+                        + "GMT"
+                        + time.Substring(signPos, 3)
+                        + ":"
+                        + time.Substring(signPos + 3);
+                }
+                else
+                {
+                    signPos = time.Length - 3;
+                    sign = time[signPos];
+                    if (sign == '-' || sign == '+')
+                    {
+                        return time.Substring(0, signPos)
+                            + "GMT"
+                            + time.Substring(signPos)
+                            + ":00";
+                    }
+                }
+            }
+
+            return time + CalculateGmtOffset();
+        }
+
+		private string CalculateGmtOffset()
+		{
+			char sign = '+';
+
+			// Note: GetUtcOffset incorporates Daylight Savings offset
+			int minutes = TimeZone.CurrentTimeZone.GetUtcOffset(ToDateTime()).Minutes;
+			if (minutes < 0)
+			{
+				sign = '-';
+				minutes = -minutes;
+			}
+			int hours = minutes / 60;
+			minutes %= 60;
+
+			return "GMT" + sign + Convert(hours) + ":" + Convert(minutes);
+		}
+
+		private static string Convert(
+			int time)
+		{
+			if (time < 10)
+			{
+				return "0" + time;
+			}
+
+			return time.ToString();
+		}
+
+		public DateTime ToDateTime()
+		{
+			string formatStr;
+			string d = time;
+			bool makeUniversal = false;
+
+			if (d.EndsWith("Z"))
+			{
+				if (HasFractionalSeconds)
+				{
+					int fCount = d.Length - d.IndexOf('.') - 2;
+					formatStr = @"yyyyMMddHHmmss." + FString(fCount) + @"\Z";
+				}
+				else
+				{
+					formatStr = @"yyyyMMddHHmmss\Z";
+				}
+			}
+			else if (time.IndexOf('-') > 0 || time.IndexOf('+') > 0)
+			{
+				d = GetTime();
+				makeUniversal = true;
+
+				if (HasFractionalSeconds)
+				{
+					int fCount = d.IndexOf("GMT") - 1 - d.IndexOf('.');
+					formatStr = @"yyyyMMddHHmmss." + FString(fCount) + @"'GMT'zzz";
+				}
+				else
+				{
+					formatStr = @"yyyyMMddHHmmss'GMT'zzz";
+				}
+			}
+			else
+			{
+				if (HasFractionalSeconds)
+				{
+					int fCount = d.Length - 1 - d.IndexOf('.');
+					formatStr = @"yyyyMMddHHmmss." + FString(fCount);
+				}
+				else
+				{
+					formatStr = @"yyyyMMddHHmmss";
+				}
+
+				// TODO?
+//				dateF.setTimeZone(new SimpleTimeZone(0, TimeZone.getDefault().getID()));
+			}
+
+			return ParseDateString(d, formatStr, makeUniversal);
+		}
+
+		private string FString(
+			int count)
+		{
+			StringBuilder sb = new StringBuilder();
+			for (int i = 0; i < count; ++i)
+			{
+				sb.Append('f');
+			}
+			return sb.ToString();
+		}
+
+		private DateTime ParseDateString(
+			string	dateStr,
+			string	formatStr,
+			bool	makeUniversal)
+		{
+			DateTime dt = DateTime.ParseExact(
+				dateStr,
+				formatStr,
+				DateTimeFormatInfo.InvariantInfo);
+
+			return makeUniversal ? dt.ToUniversalTime() : dt;
+		}
+
+		private bool HasFractionalSeconds
+		{
+			get { return time.IndexOf('.') == 14; }
+		}
+
+		private byte[] GetOctets()
+        {
+			return Encoding.ASCII.GetBytes(time);
+        }
+
+		internal override void Encode(
+            DerOutputStream derOut)
+        {
+            derOut.WriteEncoded(Asn1Tags.GeneralizedTime, GetOctets());
+        }
+
+		protected override bool Asn1Equals(
+			Asn1Object asn1Object)
+        {
+			DerGeneralizedTime other = asn1Object as DerGeneralizedTime;
+
+			if (other == null)
+				return false;
+
+			return this.time.Equals(other.time);
+        }
+
+		protected override int Asn1GetHashCode()
+		{
+            return time.GetHashCode();
+        }
+    }
+}