基于OWIN的Microsoft OAuth库生成的Bearer令牌类型识别及迁移求助

Alright, let's break this down for you. The Bearer tokens you're generating with the OWIN-based OAuth library are encrypted opaque tokens, not JWTs. OWIN's OAuth middleware defaults to creating these—they’re essentially encrypted blobs containing user claims (or a reference to server-stored claims) rather than the structured, base64-encoded JWT format you’re seeing in most migration guides.

Here’s how to migrate this authentication setup to ASP.NET Core, with two practical approaches:

Option 1: Progressive Migration (Support Old Tokens + New JWTs) #

This is the recommended path if you need to keep existing clients working while transitioning to JWTs. You’ll configure ASP.NET Core to accept both token types.

Step 1: Compatibility with OWIN’s Encryption #

OWIN uses its data protection system (or machineKey in older setups) to encrypt tokens. To decrypt these in ASP.NET Core, you need to align your data protection configuration with your old OWIN app:

• If your OWIN app used machineKey in web.config, configure ASP.NET Core’s DataProtection to use the same keys:

  builder.Services.AddDataProtection()
      .SetApplicationName("YourExistingAppName") // Must match the OWIN app's name
      .UseCryptographicAlgorithms(new AuthenticatedEncryptionOptions
      {
          EncryptionAlgorithm = EncryptionAlgorithm.AES_256_CBC,
          ValidationAlgorithm = ValidationAlgorithm.HMACSHA256
      })
      .ProtectKeysWithDpapi() // Or use file system/other storage if needed
      .UseCustomKeys(Convert.FromHexString("YourOldMachineKeyDecryptionKey"), 
                     Convert.FromHexString("YourOldMachineKeyValidationKey"));
  

Step 2: Build a Custom Authentication Handler for Old Tokens #

ASP.NET Core doesn’t have built-in support for OWIN’s opaque tokens, so you’ll need a custom handler to decrypt and validate them. Here’s a simplified example:

public class OwinOpaqueTokenHandler : AuthenticationHandler<AuthenticationSchemeOptions>
{
    private readonly IDataProtector _dataProtector;

    public OwinOpaqueTokenHandler(
        IOptionsMonitor<AuthenticationSchemeOptions> options,
        ILoggerFactory logger,
        UrlEncoder encoder,
        ISystemClock clock,
        IDataProtectionProvider dataProtectionProvider)
        : base(options, logger, encoder, clock)
    {
        // Match the protector purpose string from OWIN's OAuth middleware
        _dataProtector = dataProtectionProvider.CreateProtector(
            "Microsoft.Owin.Security.OAuth.OAuthAuthorizationServerMiddleware", 
            "Access_Token", 
            "v1");
    }

    protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
    {
        // Extract Bearer token from Authorization header
        if (!Request.Headers.TryGetValue("Authorization", out var authHeaderValues))
            return AuthenticateResult.NoResult();

        var authHeader = authHeaderValues.FirstOrDefault();
        if (string.IsNullOrEmpty(authHeader) || !authHeader.StartsWith("Bearer ", StringComparison.OrdinalIgnoreCase))
            return AuthenticateResult.NoResult();

        var token = authHeader["Bearer ".Length..];

        try
        {
            // Decrypt the token using the data protector
            var decryptedData = _dataProtector.Unprotect(Convert.FromBase64String(token));
            
            // Deserialize the authentication ticket (OWIN uses TicketSerializer)
            using var ms = new MemoryStream(decryptedData);
            using var reader = new BinaryReader(ms);
            var ticket = TicketSerializer.Default.Deserialize(reader);

            return AuthenticateResult.Success(ticket);
        }
        catch (Exception ex)
        {
            return AuthenticateResult.Fail($"Invalid opaque token: {ex.Message}");
        }
    }
}

Step 3: Register Both Authentication Schemes #

Add both your custom opaque token handler and JWT authentication to your ASP.NET Core setup:

builder.Services.AddAuthentication()
    // Register the custom OWIN token handler
    .AddScheme<AuthenticationSchemeOptions, OwinOpaqueTokenHandler>(
        "OwinBearer", 
        options => { })
    // Register JWT authentication for new clients
    .AddJwtBearer("Bearer", options =>
    {
        options.TokenValidationParameters = new TokenValidationParameters
        {
            ValidateIssuer = true,
            ValidIssuer = "YourIssuerName",
            ValidateAudience = true,
            ValidAudience = "YourAudience",
            ValidateLifetime = true,
            IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("YourJwtSecretKey"))
        };
    });

// Set authorization policy to accept either token type
builder.Services.AddAuthorization(options =>
{
    options.DefaultPolicy = new AuthorizationPolicyBuilder("OwinBearer", "Bearer")
        .RequireAuthenticatedUser()
        .Build();
});

Option 2: Full Switch to JWTs (Deprecate Old Tokens) #

If you can coordinate with clients to upgrade, you can:

1. Update your old OWIN OAuth middleware to issue JWTs alongside the existing opaque tokens (using OAuthAuthorizationServerOptions.TokenFormat to set a JWT formatter).
2. Configure ASP.NET Core to accept only JWTs once all clients have migrated.
3. Eventually shut down the old OWIN token generation.

Key Notes #

• The TicketSerializer used in the custom handler is part of Microsoft.Owin.Security—you’ll need to install the Microsoft.Owin.Security NuGet package in your ASP.NET Core project to use it.
• Test thoroughly with existing tokens to ensure decryption works correctly—mismatched application names or encryption keys will cause validation failures.

内容的提问来源于stack exchange，提问作者Stilgar