Microsoft.IdentityModel (JsonWebTokenHandler)

事实及其依据的检查

以下内容均非抄自文档。检查脚本 content/libraries/verify/microsoft-identitymodel/run.sh 于2026年10月20日在容器镜像 mcr.microsoft.com/dotnet/sdk:10.0.402-noble 中运行了 Microsoft.IdentityModel (JsonWebTokenHandler) 8.23.0；本页内容必须与它的输出一致，每条事实都列出了对应的输出行。

• JWS 算法

  HS256HS384HS512RS256RS384RS512PS256PS384PS512ES256ES384ES512

  256/384/512 的 HS、RS、PS 和 ES 签名与验证均成功；该包中没有 EdDSA 密钥类型。

  检查记录

  fact jws-algorithms = HS256, HS384, HS512, RS256, RS384, RS512, PS256, PS384, PS512, ES256, ES384, ES512
  evidence jws-algorithms: EdDSA signing with an ECDsaSecurityKey or other built-in key: no EdDSA security key type

• ES256 签名编码

  raw

  ES256 签名是 64 字节的原始 r‖s。

  检查记录

  fact jws-ecdsa-encoding = raw

• JWS 中的 DER 签名

  rejected

  DER 编码的 ES256 签名会报错 IDX10517: Signature validation failed.

  检查记录

  fact jws-der-signature = rejected
  evidence jws-der-signature: SecurityTokenSignatureKeyNotFoundException: IDX10517: Signature validation failed. The token's kid is missing. Keys tried:

• 算法允许列表

  from-key

  ValidAlgorithms 为 null 时由密钥决定：用 EC 密钥验证 RS256 令牌，报错 IDX10517。

  检查记录

  fact jwt-algorithm-allowlist = from-key
  evidence jwt-algorithm-allowlist: ValidAlgorithms null, RS256 token against the EC key: SecurityTokenSignatureKeyNotFoundException: IDX10517: Signature validation failed. The token's kid is missing. Keys tried:

• 未签名的令牌（alg none）

  opt-in

  默认情况下，未签名的令牌会报错 IDX10504: Unable to validate signature, token does not have a signature；设置 RequireSignedTokens = false 后则验证通过。

  检查记录

  fact jwt-alg-none = opt-in
  evidence jwt-alg-none: default parameters: SecurityTokenInvalidSignatureException: IDX10504: Unable to validate signature, token does not have a signature:
  evidence jwt-alg-none: RequireSignedTokens = false: valid

• 把公钥用作 HMAC 密钥

  rejected

  以 PEM 文本为密钥的 HS256 令牌，用 EC 密钥验证时报错 IDX10517。

  检查记录

  fact jwt-hmac-public-key = rejected
  evidence jwt-hmac-public-key: HS256 token keyed with the PEM text, EC key, ValidAlgorithms null: SecurityTokenSignatureKeyNotFoundException: IDX10517: Signature validation failed. The token's kid is missing. Keys tried:

• 按 alg 检查曲线

  not-enforced

  CreateToken 用 P-384 密钥签出了 ES256 令牌；用该密钥验证、且把 ValidAlgorithms 设为 ES256 时，验证成功。

  检查记录

  fact jwt-ecdsa-curve-check = not-enforced
  evidence jwt-ecdsa-curve-check: ES256 with a P-384 key: signed; validation: valid

• 默认时钟偏差

  300s

  TokenValidationParameters.DefaultClockSkew 为 5 分钟：过期不超过约 300 秒的令牌仍能验证通过。

  检查记录

  fact jwt-clock-skew = 300s
  evidence jwt-clock-skew: TokenValidationParameters.DefaultClockSkew = 00:05:00

• 是否要求过期时间声明

  yes

  不含 exp 的令牌会报错 SecurityTokenNoExpirationException: IDX10225。

  检查记录

  fact jwt-exp-required = yes
  evidence jwt-exp-required: CreateToken without Expires adds exp anyway: True
  evidence jwt-exp-required: hand-built HS256 token without exp: SecurityTokenNoExpirationException: IDX10225: Lifetime validation failed. The token is missing an Expiration Time. Tokentype:

• 默认隐藏错误详情

  yes

  验证错误会把令牌内容替换为 [PII of type ... is hidden]；设置 IdentityModelEventSource.ShowPII = true 后，这个占位符消失了。

  检查记录

  fact error-detail-hidden-by-default = yes
  evidence error-detail-hidden-by-default: PII placeholder in the default message: True; after IdentityModelEventSource.ShowPII = true: False

用法

using System.Security.Cryptography;
using Microsoft.IdentityModel.JsonWebTokens;
using Microsoft.IdentityModel.Tokens;

var key = new ECDsaSecurityKey(ECDsa.Create(ECCurve.NamedCurves.nistP256)) { KeyId = "2026-10" };
var handler = new JsonWebTokenHandler();
var token = handler.CreateToken(new SecurityTokenDescriptor
{
    Issuer = "https://auth.example.com",
    Audience = "api",
    Claims = new Dictionary<string, object> { ["sub"] = "user-42" },
    Expires = DateTime.UtcNow.AddMinutes(10),
    SigningCredentials = new SigningCredentials(key, SecurityAlgorithms.EcdsaSha256),
});

// Pin the algorithm (ES256 is not tied to P-256 here) and shrink the 5-minute default skew.
var result = await handler.ValidateTokenAsync(token, new TokenValidationParameters
{
    IssuerSigningKey = key,
    ValidIssuer = "https://auth.example.com",
    ValidAudience = "api",
    ValidAlgorithms = new[] { SecurityAlgorithms.EcdsaSha256 },
    ClockSkew = TimeSpan.FromSeconds(30),
});
Console.WriteLine($"valid: {result.IsValid}, sub: {result.Claims["sub"]}");