56 lines
1.9 KiB
C#
56 lines
1.9 KiB
C#
|
using System;
|
||
|
|
using System.Security.Cryptography;
|
||
|
|
|
||
|
|
namespace PCL.Core.Utils.Encryption
|
||
|
|
{
|
||
|
|
public class AesGcmProvider : IEncryptionProvider
|
||
|
|
{
|
||
|
|
public static AesGcmProvider Instance { get; } = new();
|
||
|
|
|
||
|
|
private const int NonceSize = 12; // 96 bits
|
||
|
|
private const int TagSize = 16; // 128 bits
|
||
|
|
|
||
|
|
public byte[] Encrypt(ReadOnlySpan<byte> data, ReadOnlySpan<byte> key)
|
||
|
|
{
|
||
|
|
byte[] nonce = new byte[NonceSize];
|
||
|
|
RandomNumberGenerator.Fill(nonce);
|
||
|
|
|
||
|
|
byte[] tag = new byte[TagSize];
|
||
|
|
byte[] ciphertext = new byte[data.Length];
|
||
|
|
|
||
|
|
using (var aesGcm = new AesGcm(key, TagSize))
|
||
|
|
{
|
||
|
|
aesGcm.Encrypt(nonce, data, ciphertext, tag);
|
||
|
|
}
|
||
|
|
|
||
|
|
// [Nonce(12)] [Tag(16)] [Ciphertext(n)]
|
||
|
|
byte[] result = new byte[NonceSize + TagSize + ciphertext.Length];
|
||
|
|
Buffer.BlockCopy(nonce, 0, result, 0, NonceSize);
|
||
|
|
Buffer.BlockCopy(tag, 0, result, NonceSize, TagSize);
|
||
|
|
Buffer.BlockCopy(ciphertext, 0, result, NonceSize + TagSize, ciphertext.Length);
|
||
|
|
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
|
||
|
|
public byte[] Decrypt(ReadOnlySpan<byte> data, ReadOnlySpan<byte> key)
|
||
|
|
{
|
||
|
|
if (data.Length < NonceSize + TagSize)
|
||
|
|
throw new ArgumentException("加密数据长度不足。");
|
||
|
|
|
||
|
|
ReadOnlySpan<byte> nonce = data.Slice(0, NonceSize);
|
||
|
|
ReadOnlySpan<byte> tag = data.Slice(NonceSize, TagSize);
|
||
|
|
ReadOnlySpan<byte> ciphertext = data.Slice(NonceSize + TagSize);
|
||
|
|
|
||
|
|
byte[] plaintext = new byte[ciphertext.Length];
|
||
|
|
|
||
|
|
using (var aesGcm = new AesGcm(key, TagSize))
|
||
|
|
{
|
||
|
|
aesGcm.Decrypt(nonce, ciphertext, tag, plaintext);
|
||
|
|
}
|
||
|
|
|
||
|
|
return plaintext;
|
||
|
|
}
|
||
|
|
|
||
|
|
public bool IsSupported { get => AesGcm.IsSupported; }
|
||
|
|
}
|
||
|
|
}
|