crypto/src/asn1/x9/X9IntegerConverter.cs


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using System;

using Org.BouncyCastle.Math;
using Org.BouncyCastle.Math.EC;

namespace Org.BouncyCastle.Asn1.X9
{
    public abstract class X9IntegerConverter
    {
        public static int GetByteLength(ECFieldElement fe)
        {
            return (fe.FieldSize + 7) / 8;
        }

        public static int GetByteLength(ECCurve c)
        {
            return (c.FieldSize + 7) / 8;
        }

        public static byte[] IntegerToBytes(BigInteger s, int qLength)
        {
            byte[] bytes = s.ToByteArrayUnsigned();

            if (qLength < bytes.Length)
            {
                byte[] tmp = new byte[qLength];
                Array.Copy(bytes, bytes.Length - tmp.Length, tmp, 0, tmp.Length);
                return tmp;
            }
            else if (qLength > bytes.Length)
            {
                byte[] tmp = new byte[qLength];
                Array.Copy(bytes, 0, tmp, tmp.Length - bytes.Length, bytes.Length);
                return tmp;
            }

            return bytes;
        }
    }
}