介绍

微软在 .NET 6 中引入一些更简单的 API 来使用 HMAC 哈希算法（MD5/SHA1/SHA256/SHA384/SHA512)

微软的叫法叫做?HMAC One-Shoot method, HMAC 算法在普通的哈希算法基础上增加了一个 key，通过 key 提升了安全性，能够有效避免密码泄露被彩虹表反推出真实密码， JWT(Json Web Token) 除了可以使用 RSA 方式外也支持使用 HMAC 。

New API

新增的 API 定义如下：

namespace?System.Security.Cryptography?{
????public?partial?class?HMACMD5?{
????????public?static?byte[]?HashData(byte[]?key,?byte[]?source);
????????public?static?byte[]?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source);
????????public?static?int?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination);
????????public?static?bool?TryHashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination,?out?int?bytesWritten);
????}

????public?partial?class?HMACSHA1?{
????????public?static?byte[]?HashData(byte[]?key,?byte[]?source);
????????public?static?byte[]?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source);
????????public?static?int?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination);
????????public?static?bool?TryHashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination,?out?int?bytesWritten);
????}

????public?partial?class?HMACSHA256?{
????????public?static?byte[]?HashData(byte[]?key,?byte[]?source);
????????public?static?byte[]?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source);
????????public?static?int?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination);
????????public?static?bool?TryHashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination,?out?int?bytesWritten);
????}

????public?partial?class?HMACSHA384?{
????????public?static?byte[]?HashData(byte[]?key,?byte[]?source);
????????public?static?byte[]?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source);
????????public?static?int?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination);
????????public?static?bool?TryHashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination,?out?int?bytesWritten);
????}

????public?partial?class?HMACSHA512?{
????????public?static?byte[]?HashData(byte[]?key,?byte[]?source);
????????public?static?byte[]?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source);
????????public?static?int?HashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination);
????????public?static?bool?TryHashData(ReadOnlySpan<byte>?key,?ReadOnlySpan<byte>?source,?Span<byte>?destination,?out?int?bytesWritten);
????}
}

Sample Before

在之前的版本中想要实现计算 HMAC 算法会比较复杂，之前实现了一个?HashHelper?来封装了常用的 Hash 算法和 HMAC 算法，HashHelper?部分代码如下，完整代码可以从 Github 获取：https://github.com/WeihanLi/WeihanLi.Common/blob/dev/src/WeihanLi.Common/Helpers/HashHelper.cs

///?<summary>
///?获取哈希之后的字符串
///?</summary>
///?<param?name="type">哈希类型</param>
///?<param?name="source">源</param>
///?<param?name="key">key</param>
///?<param?name="isLower">是否是小写</param>
///?<returns>哈希算法处理之后的字符串</returns>
public?static?string?GetHashedString(HashType?type,?byte[]?source,?byte[]??key,?bool?isLower?=?false)
{
????Guard.NotNull(source,?nameof(source));
????if?(source.Length?==?0)
????{
????????return?string.Empty;
????}
????var?hashedBytes?=?GetHashedBytes(type,?source,?key);
????var?sbText?=?new?StringBuilder();
????if?(isLower)
????{
????????foreach?(var?b?in?hashedBytes)
????????{
????????????sbText.Append(b.ToString("x2"));
????????}
????}
????else
????{
????????foreach?(var?b?in?hashedBytes)
????????{
????????????sbText.Append(b.ToString("X2"));
????????}
????}
????return?sbText.ToString();
}

///?<summary>
///?计算字符串Hash值
///?</summary>
///?<param?name="type">hash类型</param>
///?<param?name="str">要hash的字符串</param>
///?<returns>hash过的字节数组</returns>
public?static?byte[]?GetHashedBytes(HashType?type,?string?str)?=>?GetHashedBytes(type,?str,?Encoding.UTF8);

///?<summary>
///?计算字符串Hash值
///?</summary>
///?<param?name="type">hash类型</param>
///?<param?name="str">要hash的字符串</param>
///?<param?name="encoding">编码类型</param>
///?<returns>hash过的字节数组</returns>
public?static?byte[]?GetHashedBytes(HashType?type,?string?str,?Encoding?encoding)
{
????Guard.NotNull(str,?nameof(str));
????if?(str?==?string.Empty)
????{
????????return?Array.Empty<byte>();
????}
????var?bytes?=?encoding.GetBytes(str);
????return?GetHashedBytes(type,?bytes);
}

///?<summary>
///?获取Hash后的字节数组
///?</summary>
///?<param?name="type">哈希类型</param>
///?<param?name="bytes">原字节数组</param>
///?<returns></returns>
public?static?byte[]?GetHashedBytes(HashType?type,?byte[]?bytes)?=>?GetHashedBytes(type,?bytes,?null);

///?<summary>
///?获取Hash后的字节数组
///?</summary>
///?<param?name="type">哈希类型</param>
///?<param?name="key">key</param>
///?<param?name="bytes">原字节数组</param>
///?<returns></returns>
public?static?byte[]?GetHashedBytes(HashType?type,?byte[]?bytes,?byte[]??key)
{
????Guard.NotNull(bytes,?nameof(bytes));
????if?(bytes.Length?==?0)
????{
????????return?bytes;
????}

????HashAlgorithm?algorithm?=?null!;
????try
????{
????????if?(key?==?null)
????????{
????????????algorithm?=?type?switch
????????????{
????????????????????HashType.SHA1?=>?new?SHA1Managed(),
????????????????????HashType.SHA256?=>?new?SHA256Managed(),
????????????????????HashType.SHA384?=>?new?SHA384Managed(),
????????????????????HashType.SHA512?=>?new?SHA512Managed(),
????????????????????_?=>?MD5.Create()
????????????};
????????}
????????else
????????{
????????????algorithm?=?type?switch
????????????{
????????????????????HashType.SHA1?=>?new?HMACSHA1(key),
????????????????????HashType.SHA256?=>?new?HMACSHA256(key),
????????????????????HashType.SHA384?=>?new?HMACSHA384(key),
????????????????????HashType.SHA512?=>?new?HMACSHA512(key),
????????????????????_?=>?new?HMACMD5(key)
????????????};
????????}
????????return?algorithm.ComputeHash(bytes);
????}
????finally
????{
????????algorithm.Dispose();
????}
}

使用示例如下：

HashHelper.GetHashedBytes(HashType.MD5,?"test");
HashHelper.GetHashedBytes(HashType.MD5,?"test".GetBytes());
HashHelper.GetHashedBytes(HashType.MD5,?"test",?"testKey");
HashHelper.GetHashedBytes(HashType.MD5,?"test".GetBytes(),?"testKey".GetBytes());

HashHelper.GetHashedString(HashType.MD5,?"test");
HashHelper.GetHashedString(HashType.SHA1,?"test".GetBytes());
HashHelper.GetHashedString(HashType.SHA256,?"test",?"testKey");
HashHelper.GetHashedString(HashType.MD5,?"test".GetBytes(),?"testKey".GetBytes());

New API Sample

有了新的 API 以后可以怎么简化呢，来看下面的示例：

var?bytes?=?"test".GetBytes();
var?keyBytes?=?"test-key".GetBytes();

//?HMACMD5
var?hmd5V1?=?HMACMD5.HashData(keyBytes,?bytes);
var?hmd5V2?=?HashHelper.GetHashedBytes(HashType.MD5,?bytes,?keyBytes);
Console.WriteLine(hmd5V2.SequenceEqual(hmd5V1));

//?HMACSHA1
var?hsha1V1?=?HMACSHA1.HashData(keyBytes,?bytes);
var?hsha1V2?=?HashHelper.GetHashedBytes(HashType.SHA1,?bytes,?keyBytes);
Console.WriteLine(hsha1V2.SequenceEqual(hsha1V1));

//?HMACSHA256
var?hsha256V1?=?HMACSHA256.HashData(keyBytes,?bytes);
var?hsha256V2?=?HashHelper.GetHashedBytes(HashType.SHA256,?bytes,?keyBytes);
Console.WriteLine(hsha256V2.SequenceEqual(hsha256V1));

//?HMACSHA384
var?hsha384V1?=?HMACSHA384.HashData(keyBytes?,bytes);
var?hsha384V2?=?HashHelper.GetHashedBytes(HashType.SHA384,?bytes,?keyBytes);
Console.WriteLine(hsha384V2.SequenceEqual(hsha384V1));

//?HMACSHA512
var?hsha512V1?=?HMACSHA512.HashData(keyBytes?,bytes);
var?hsha512V2?=?HashHelper.GetHashedBytes(HashType.SHA512,?bytes,?keyBytes);
Console.WriteLine(hsha512V2.SequenceEqual(hsha512V1));

直接使用对应的 HMAC 哈希算法的?HashData?方法即可，传入对应的 key 和原始内容就可以了，上面是和我们?HashHelper?封装的方法进行对比，看结果是否一致，都是一致的，输出结果如下：

对于普通的哈希算法，微软其实在 .NET 5 就已经支持了上面的用法，可以尝试一下下面的代码：

var?bytes?=?"test".GetBytes();

//?MD5
var?md5V1?=?MD5.HashData(bytes);
var?md5V2?=?HashHelper.GetHashedBytes(HashType.MD5,?bytes);
Console.WriteLine(md5V2.SequenceEqual(md5V1));

//?SHA1
var?sha1V1?=?SHA1.HashData(bytes);
var?sha1V2?=?HashHelper.GetHashedBytes(HashType.SHA1,?bytes);
Console.WriteLine(sha1V2.SequenceEqual(sha1V1));

//?SHA256
var?sha256V1?=?SHA256.HashData(bytes);
var?sha256V2?=?HashHelper.GetHashedBytes(HashType.SHA256,?bytes);
Console.WriteLine(sha256V2.SequenceEqual(sha256V1));

//?SHA384
var?sha384V1?=?SHA384.HashData(bytes);
var?sha384V2?=?HashHelper.GetHashedBytes(HashType.SHA384,?bytes);
Console.WriteLine(sha384V2.SequenceEqual(sha384V1));

//?SHA512
var?sha512V1?=?SHA512.HashData(bytes);
var?sha512V2?=?HashHelper.GetHashedBytes(HashType.SHA512,?bytes);
Console.WriteLine(sha512V2.SequenceEqual(sha512V1));

很多时候我们可能都会要使用 MD5 或者 SHA1 之后的字符串，不知道为什么微软没有直接获取一个字符串的方法，如果有这样一个方法，就会更方便了，相比之后，感觉还是自己封装的?HashHelper?使用起来更舒服一些，哈哈，这样的静态方法不够抽象如果要动态替换哈希算法代码可能就有点...

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无欲则刚的博客：.NET 6 中哈希算法的简化用法

作者：[db:作者] 时间：2021-09-10 18:59

介绍

New API

Sample Before

New API Sample

More

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推荐 更多<<

无欲则刚的博客：.NET 6 中哈希算法的简化用法

作者：[db:作者] 时间：2021-09-10 18:59

介绍

New API

Sample Before

New API Sample

More

最新 更多<<

推荐 更多<<

最新更多<<

推荐更多<<