NBitcoin.BouncyCastle.Math.EC.ECCurve.DecodePoint C# (CSharp) Method

		public virtual ECPoint DecodePoint(byte[] encoded)
		{
			ECPoint p = null;
			int expectedLength = (FieldSize + 7) / 8;

			byte type = encoded[0];
			switch(type)
			{
				case 0x00: // infinity
					{
						if(encoded.Length != 1)
							throw new ArgumentException("Incorrect length for infinity encoding", "encoded");

						p = Infinity;
						break;
					}

				case 0x02: // compressed
				case 0x03: // compressed
					{
						if(encoded.Length != (expectedLength + 1))
							throw new ArgumentException("Incorrect length for compressed encoding", "encoded");

						int yTilde = type & 1;
						BigInteger X = new BigInteger(1, encoded, 1, expectedLength);

						p = DecompressPoint(yTilde, X);
						if(!p.SatisfiesCofactor())
							throw new ArgumentException("Invalid point");

						break;
					}

				case 0x04: // uncompressed
					{
						if(encoded.Length != (2 * expectedLength + 1))
							throw new ArgumentException("Incorrect length for uncompressed encoding", "encoded");

						BigInteger X = new BigInteger(1, encoded, 1, expectedLength);
						BigInteger Y = new BigInteger(1, encoded, 1 + expectedLength, expectedLength);

						p = ValidatePoint(X, Y);
						break;
					}

				case 0x06: // hybrid
				case 0x07: // hybrid
					{
						if(encoded.Length != (2 * expectedLength + 1))
							throw new ArgumentException("Incorrect length for hybrid encoding", "encoded");

						BigInteger X = new BigInteger(1, encoded, 1, expectedLength);
						BigInteger Y = new BigInteger(1, encoded, 1 + expectedLength, expectedLength);

						if(Y.TestBit(0) != (type == 0x07))
							throw new ArgumentException("Inconsistent Y coordinate in hybrid encoding", "encoded");

						p = ValidatePoint(X, Y);
						break;
					}

				default:
					throw new FormatException("Invalid point encoding " + type);
			}

			if(type != 0x00 && p.IsInfinity)
				throw new ArgumentException("Invalid infinity encoding", "encoded");

			return p;
		}
	}

 public X9ECPoint(
     ECCurve			c,
     Asn1OctetString	s)
 {
     this.p = c.DecodePoint(s.GetOctets());
 }