feat(infra): move authentication implementations and add ITokenGenerator

src/FiscalOS.Infra/Authentication/TokenGenerator.cs

@@ -0,0 +1,78 @@
+namespace FiscalOS.Infra.Authentication;
+
+public sealed class TokenGenerator : ITokenGenerator
+{
+  private const int RefreshTokenExpiryInHours = 12;
+  private readonly IOptions<JwtOptions> _jwtOptions;
+  private readonly TimeProvider _timeProvider;
+
+  private TokenGenerator(
+    TimeProvider timeProvider,
+    IOptions<JwtOptions> jwtOptions
+  )
+  {
+    _timeProvider = timeProvider;
+    _jwtOptions = jwtOptions;
+  }
+
+  public static TokenGenerator From(IServiceProvider serviceProvider)
+  {
+    var timeProvider = serviceProvider.GetRequiredService<TimeProvider>();
+    var jwtOptions = serviceProvider.GetRequiredService<IOptions<JwtOptions>>();
+    return new(timeProvider, jwtOptions);
+  }
+
+  public static TokenGenerator From(
+    TimeProvider timeProvider,
+    IOptions<JwtOptions> jwtOptions
+  )
+  {
+    return new(timeProvider, jwtOptions);
+  }
+
+  public string GenerateAccessToken(User user)
+  {
+    var tokenHandler = new JwtSecurityTokenHandler();
+    var secretKeyBytes = Encoding.UTF8.GetBytes(_jwtOptions.Value.Secret);
+    var issuedAt = _timeProvider.GetUtcNow();
+    var expiresAt = issuedAt.AddMinutes(_jwtOptions.Value.ExpiryInMinutes);
+    List<Claim> claims = [
+      new(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
+      new(JwtRegisteredClaimNames.Sub, user.Id.ToString()),
+    ];
+
+    var descriptor = new SecurityTokenDescriptor()
+    {
+      Subject = new(claims),
+      IssuedAt = issuedAt.UtcDateTime,
+      Expires = expiresAt.UtcDateTime,
+      Issuer = _jwtOptions.Value.Issuer,
+      Audience = _jwtOptions.Value.Audience,
+      SigningCredentials = new(
+        new SymmetricSecurityKey(secretKeyBytes),
+        SecurityAlgorithms.HmacSha256Signature
+      ),
+    };
+
+    var securityToken = tokenHandler.CreateJwtSecurityToken(descriptor);
+    var jwtToken = tokenHandler.WriteToken(securityToken);
+
+    return jwtToken;
+  }
+
+  public RefreshToken GenerateRefreshToken(User user)
+  {
+    var expiresAt = _timeProvider
+      .GetUtcNow()
+      .AddHours(RefreshTokenExpiryInHours);
+
+    return RefreshToken.From(user.Id, GenerateToken(), expiresAt);
+  }
+
+  private static string GenerateToken()
+  {
+    var randomBytes = RandomNumberGenerator.GetBytes(32);
+    var token = Convert.ToBase64String(randomBytes);
+    return token;
+  }
+}