加密 JWT 安全令牌支持的算法

Question

我正在尝试使用以下代码段对我的 JWt 进行签名和编码：

var claims = new Claim[] { new SomeClaimes() };
var scKey = Encoding.UTF8.GetBytes("SOME KEY");
var ecKey = Encoding.UTF8.GetBytes("SOME OTHER KEY");
var tokenDescriptor = new SecurityTokenDescriptor {
    Subject = new ClaimsIdentity(claims),
    SigningCredentials = new SigningCredentials(
        new SymmetricSecurityKey(
            scKey),
            SecurityAlgorithms.HmacSha512),
    EncryptingCredentials = new EncryptingCredentials(
        new SymmetricSecurityKey(
            ecKey),
            // I tryied all possible combination of algorithms here:
            SecurityAlgorithms.XXXX,
            SecurityAlgorithms.YYYY), 
    Issuer = "My Jwt Issuer",
    Audience = "My Jwt Audience",
    IssuedAt = DateTime.UtcNow,
    Expires = DateTime.Now.AddDays(7),
};
var tokenHandler = new JwtSecurityTokenHandler();
var token = tokenHandler.CreateJwtSecurityToken(tokenDescriptor);
var jwt = tokenHandler.WriteToken(token);

但是当我运行代码时，出现错误：

加密失败。不支持：算法：“{0}”，安全密钥：“{1}”。

其中{0}和{1}是任意组合XXXX，并YYYY在上面的代码（是的，我写了一个反射片断，并尝试他们的所有可能的组合）。哪些是用于编码（和解码）签名 JWT 的受支持算法？

Answer 1

最后我找到了答案：

var claims = new Claim[] { new SomeClaimes() };
var scKey = Encoding.UTF8.GetBytes("SOME KEY");
var ecKeyTemp = Encoding.UTF8.GetBytes("SOME OTHER KEY");

// Note that the ecKey should have 256 / 8 length:
byte[] ecKey = new byte[256 / 8];
Array.Copy(ecKeyTemp, ecKey, 256 / 8);

var tokenDescriptor = new SecurityTokenDescriptor {
    Subject = new ClaimsIdentity(claims),
    SigningCredentials = new SigningCredentials(
        new SymmetricSecurityKey(
            scKey),
            SecurityAlgorithms.HmacSha512),
    EncryptingCredentials = new EncryptingCredentials(
        new SymmetricSecurityKey(
            ecKey),
            SecurityAlgorithms.Aes256KW,
            SecurityAlgorithms.Aes256CbcHmacSha512), 
    Issuer = "My Jwt Issuer",
    Audience = "My Jwt Audience",
    IssuedAt = DateTime.UtcNow,
    Expires = DateTime.Now.AddDays(7),
};
var tokenHandler = new JwtSecurityTokenHandler();
var token = tokenHandler.CreateJwtSecurityToken(tokenDescriptor);
var jwt = tokenHandler.WriteToken(token);

如您所见，使用SecurityAlgorithms.Aes256KWas密钥加密算法和SecurityAlgorithms.Aes256CbcHmacSha512as加密算法将完成这项工作。注意用于加密算法的密钥应该有256 / 8长度。