获取字符串的SHA-256字符串

Question

我有一些string,我想用使用C#的SHA-256哈希函数来哈希它.我想要这样的东西:

 string hashString = sha256_hash("samplestring");

框架中是否有内置功能可以执行此操作？

Answer 1

实施可能就是这样

public static String sha256_hash(String value) {
  StringBuilder Sb = new StringBuilder();

  using (SHA256 hash = SHA256Managed.Create()) {
    Encoding enc = Encoding.UTF8;
    Byte[] result = hash.ComputeHash(enc.GetBytes(value));

    foreach (Byte b in result)
      Sb.Append(b.ToString("x2"));
  }

  return Sb.ToString();
}

编辑: Linq实现更简洁,但可能不太可读:

public static String sha256_hash(String value) {
  using (SHA256 hash = SHA256Managed.Create()) {
    return String.Concat(hash
      .ComputeHash(Encoding.UTF8.GetBytes(value))
      .Select(item => item.ToString("x2")));
  }
} 

编辑2: .NET Core

public static String sha256_hash(string value)
{
    StringBuilder Sb = new StringBuilder();

    using (var hash = SHA256.Create())            
    {
        Encoding enc = Encoding.UTF8;
        Byte[] result = hash.ComputeHash(enc.GetBytes(value));

        foreach (Byte b in result)
            Sb.Append(b.ToString("x2"));
    }

    return Sb.ToString();
}

Answer 2

从 .NET 5 开始，您可以使用新Convert.ToHexString方法将哈希字节数组转换为（十六进制）字符串，而无需使用 orStringBuilder等.ToString("X0")​​：

public static string HashWithSHA256(string value)
{
  using var hash = SHA256.Create();
  var byteArray = hash.ComputeHash(Encoding.UTF8.GetBytes(value));
  return Convert.ToHexString(byteArray);
}