100 lines
3.1 KiB
C#
100 lines
3.1 KiB
C#
#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
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#pragma warning disable
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using System;
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using BestHTTP.SecureProtocol.Org.BouncyCastle.Math;
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using BestHTTP.SecureProtocol.Org.BouncyCastle.Security;
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namespace BestHTTP.SecureProtocol.Org.BouncyCastle.Utilities
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{
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/**
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* BigInteger utilities.
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*/
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public abstract class BigIntegers
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{
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private const int MaxIterations = 1000;
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/**
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* Return the passed in value as an unsigned byte array.
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*
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* @param value value to be converted.
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* @return a byte array without a leading zero byte if present in the signed encoding.
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*/
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public static byte[] AsUnsignedByteArray(
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BigInteger n)
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{
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return n.ToByteArrayUnsigned();
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}
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/**
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* Return the passed in value as an unsigned byte array of specified length, zero-extended as necessary.
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*
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* @param length desired length of result array.
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* @param n value to be converted.
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* @return a byte array of specified length, with leading zeroes as necessary given the size of n.
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*/
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public static byte[] AsUnsignedByteArray(int length, BigInteger n)
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{
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byte[] bytes = n.ToByteArrayUnsigned();
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if (bytes.Length > length)
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throw new ArgumentException("standard length exceeded", "n");
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if (bytes.Length == length)
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return bytes;
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byte[] tmp = new byte[length];
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Array.Copy(bytes, 0, tmp, tmp.Length - bytes.Length, bytes.Length);
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return tmp;
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}
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/**
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* Return a random BigInteger not less than 'min' and not greater than 'max'
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*
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* @param min the least value that may be generated
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* @param max the greatest value that may be generated
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* @param random the source of randomness
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* @return a random BigInteger value in the range [min,max]
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*/
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public static BigInteger CreateRandomInRange(
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BigInteger min,
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BigInteger max,
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// TODO Should have been just Random class
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SecureRandom random)
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{
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int cmp = min.CompareTo(max);
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if (cmp >= 0)
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{
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if (cmp > 0)
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throw new ArgumentException("'min' may not be greater than 'max'");
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return min;
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}
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if (min.BitLength > max.BitLength / 2)
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{
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return CreateRandomInRange(BigInteger.Zero, max.Subtract(min), random).Add(min);
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}
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for (int i = 0; i < MaxIterations; ++i)
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{
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BigInteger x = new BigInteger(max.BitLength, random);
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if (x.CompareTo(min) >= 0 && x.CompareTo(max) <= 0)
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{
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return x;
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}
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}
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// fall back to a faster (restricted) method
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return new BigInteger(max.Subtract(min).BitLength - 1, random).Add(min);
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}
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public static int GetUnsignedByteLength(BigInteger n)
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{
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return (n.BitLength + 7) / 8;
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}
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}
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}
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#pragma warning restore
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#endif
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