Swarm/DysonNetwork.Sphere/Auth/CompactTokenService.cs

94 lines
2.9 KiB
C#

using System.Security.Cryptography;
namespace DysonNetwork.Sphere.Auth;
public class CompactTokenService(IConfiguration config)
{
private readonly string _privateKeyPath = config["Jwt:PrivateKeyPath"]
?? throw new InvalidOperationException("Jwt:PrivateKeyPath configuration is missing");
public string CreateToken(Session session)
{
// Load the private key for signing
var privateKeyPem = File.ReadAllText(_privateKeyPath);
using var rsa = RSA.Create();
rsa.ImportFromPem(privateKeyPem);
// Create and return a single token
return CreateCompactToken(session.Id, rsa);
}
private string CreateCompactToken(Guid sessionId, RSA rsa)
{
// Create the payload: just the session ID
var payloadBytes = sessionId.ToByteArray();
// Base64Url encode the payload
var payloadBase64 = Base64UrlEncode(payloadBytes);
// Sign the payload with RSA-SHA256
var signature = rsa.SignData(payloadBytes, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
// Base64Url encode the signature
var signatureBase64 = Base64UrlEncode(signature);
// Combine payload and signature with a dot
return $"{payloadBase64}.{signatureBase64}";
}
public bool ValidateToken(string token, out Guid sessionId)
{
sessionId = Guid.Empty;
try
{
// Split the token
var parts = token.Split('.');
if (parts.Length != 2)
return false;
// Decode the payload
var payloadBytes = Base64UrlDecode(parts[0]);
// Extract session ID
sessionId = new Guid(payloadBytes);
// Load public key for verification
var publicKeyPem = File.ReadAllText(config["Jwt:PublicKeyPath"]!);
using var rsa = RSA.Create();
rsa.ImportFromPem(publicKeyPem);
// Verify signature
var signature = Base64UrlDecode(parts[1]);
return rsa.VerifyData(payloadBytes, signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
}
catch
{
return false;
}
}
// Helper methods for Base64Url encoding/decoding
private static string Base64UrlEncode(byte[] data)
{
return Convert.ToBase64String(data)
.TrimEnd('=')
.Replace('+', '-')
.Replace('/', '_');
}
private static byte[] Base64UrlDecode(string base64Url)
{
string padded = base64Url
.Replace('-', '+')
.Replace('_', '/');
switch (padded.Length % 4)
{
case 2: padded += "=="; break;
case 3: padded += "="; break;
}
return Convert.FromBase64String(padded);
}
}