Question

在编码之前，我注意到有关SHA256的一些奇怪之处，因为它似乎比哈希的字母生成更多的整数。起初我以为我只是想象它，所以我做了一个快速测试以确保。令人惊讶的是，我的测试似乎证明SHA256支持它生成的哈希值中的整数值。我想知道为什么会这样。哈希索引是一个字母和一个数字之间的差异应该是完全相同的吗？这是我的测试示例：

namespace TestingApp
{
    static class Program
    {
        private static string letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
        private static char[] characters = letters.ToCharArray();
        private static Random _rng = new Random();

        static void Main(string[] args)
        {
            int totalIntegers = 0;
            int totalLetters = 0;
            for (int testingIntervals = 0; testingIntervals < 3000; testingIntervals++)
            {
                string randomString = NextString(10);
                string checksum = DreamforceChecksum.GenerateSHA256(randomString);
                int integerCount = checksum.Count(Char.IsDigit);
                int letterCount = checksum.Count(Char.IsLetter);
                Console.WriteLine("String: " + randomString);
                Console.WriteLine("Checksum: " + checksum);
                Console.WriteLine("Integers: " + integerCount);
                Console.WriteLine("Letters: " + letterCount);
                totalIntegers += integerCount;
                totalLetters += letterCount;
            }
            Console.WriteLine("Total Integers: " + totalIntegers);
            Console.WriteLine("Total Letters: " + totalLetters);
            Console.Read();
        }

        private static string NextString(int length)
        {
            StringBuilder builder = new StringBuilder();
            for (int i = 0; i < length; i++)
            {
                builder.Append(characters[_rng.Next(characters.Length)]);
            }
            return builder.ToString();
        }
    }
}

和我的校验和/哈希类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace DreamforceFramework.Framework.Cryptography
{
    public static class DreamforceChecksum
    {
        private static readonly SHA256Managed _shaManagedInstance = new SHA256Managed();
        private static readonly StringBuilder _checksumBuilder = new StringBuilder();
        public static string GenerateSHA256(string text)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(text);
            byte[] hash = _shaManagedInstance.ComputeHash(bytes);
            _checksumBuilder.Clear();
            for (int index = 0; index < hash.Length; index++)
            {
                _checksumBuilder.Append(hash[index].ToString("x2"));
            }
            return _checksumBuilder.ToString();
        }

        public static byte[] GenerateSHA256Bytes(string text)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(text);
            byte[] hash = _shaManagedInstance.ComputeHash(bytes);
            _checksumBuilder.Clear();
            for (int index = 0; index < hash.Length; index++)
            {
                _checksumBuilder.Append(hash[index].ToString("x2"));
            }
            return Encoding.UTF8.GetBytes(_checksumBuilder.ToString());
        }

        public static bool ValidateDataIntegrity(string data, string targetHashcode)
        {
            return GenerateSHA256(data).Equals(targetHashcode);
        }
    }
}

我已多次运行我的测试，并且每次看起来哈希中生成的整数比字母更多。以下是3次测试：

有谁知道为什么SHA256似乎更喜欢数字而不是字母和数字的平均分配？

Answer 1

鉴于可能有10位数和6位字母，比例应大致为10：6。这与您的结果一致。

Answer 2

输出为十六进制。 0-9和a-f

SHA256是否支持整数？

2 个答案: