Org.BouncyCastle.Math.BigInteger.Negate C# (CSharp) Method

		public BigInteger Negate()
		{
			if (sign == 0)
				return this;

			return new BigInteger(-sign, magnitude, false);
		}

        /// <summary>
        /// MPI encoded numbers are produced by the OpenSSL BN_bn2mpi function.
        /// They consist of a 4 byte big endian length field, followed by the stated number of bytes representing the number in big endian format (with a sign bit).
        /// </summary>
        /// <param name="value"></param>
        /// <param name="includeLength">Indicates whether the 4 byte length field should be included</param>
        /// <returns></returns>
        public static byte[] Encode(BigInteger value,bool includeLength=true)
        {
            if(value.Equals(BigInteger.Zero))
            {
                if(!includeLength)
                { return new byte[0]; }
                return new byte[] { 0x00,0x00,0x00,0x00 };
            }

            bool isNegative=value.CompareTo(BigInteger.Zero)<0;
            if(isNegative)
            { value=value.Negate(); }

            byte[] array=value.ToByteArray();
            int length=array.Length;
            if((array[0] & 0x80)==0x80)
            { length++; }

            if(includeLength)
            {
                byte[] result=new byte[length+4];
                Array.Copy(array,0,result,length-array.Length+3,array.Length);
                ((uint)length).ToByteArrayBe(result);

                if(isNegative)
                { result[4]|=0x80; }
                return result;
            }
            else
            {
                byte[] result;
                if(length!=array.Length)
                {
                    result=new byte[length];
                    Array.Copy(array,0,result,1,array.Length);
                }
                else
                { result=array; }

                if(isNegative)
                { result[0]|=0x80; }

                return result;
            }
        }