fix(jwt): Mark date/time in JWTs as integers (#118)

* fix(jwt): Mark date/time in JWTs as integers

* Fix type

Author: cbetta

src/Gr4vy.Tests/AuthTest.cs

@@ -69,11 +69,15 @@ public void GetToken_ShouldCreateValidSignedJwtToken()
         var headers = jwtToken.Header;
 
         Assert.That(headers["kid"], Is.EqualTo(Thumbprint));
+        
         Assert.That(scopes.Count(s => s.Value == "*.read"), Is.EqualTo(1));
         Assert.That(scopes.Count(s => s.Value == "*.write"), Is.EqualTo(1));
         Assert.NotNull(jwtToken.Claims.FirstOrDefault(c => c.Type == JwtRegisteredClaimNames.Iat));
+        Assert.That(jwtToken.Claims.FirstOrDefault(c => c.Type == JwtRegisteredClaimNames.Iat)?.ValueType, Is.EqualTo(ClaimValueTypes.Integer64));
         Assert.NotNull(jwtToken.Claims.FirstOrDefault(c => c.Type == JwtRegisteredClaimNames.Nbf));
+        Assert.That(jwtToken.Claims.FirstOrDefault(c => c.Type == JwtRegisteredClaimNames.Nbf)?.ValueType, Is.EqualTo(ClaimValueTypes.Integer64));
         Assert.NotNull(jwtToken.Claims.FirstOrDefault(c => c.Type == JwtRegisteredClaimNames.Exp));
+        Assert.That(jwtToken.Claims.FirstOrDefault(c => c.Type == JwtRegisteredClaimNames.Exp)?.ValueType, Is.EqualTo(ClaimValueTypes.Integer64));
         Assert.That(
             jwtToken.Claims.First(c => c.Type == JwtRegisteredClaimNames.Iss).Value,
             Does.StartWith("speakeasy-sdk/csharp")

src/Gr4vy/Auth.cs

@@ -134,15 +134,18 @@ public static string GetToken(
             new Claim("iss", issuer),
             new Claim(
                 JwtRegisteredClaimNames.Iat,
-                new DateTimeOffset(now).ToUnixTimeSeconds().ToString()
+                new DateTimeOffset(now).ToUnixTimeSeconds().ToString(),
+                ClaimValueTypes.Integer64
             ),
             new Claim(
                 JwtRegisteredClaimNames.Nbf,
-                new DateTimeOffset(now).ToUnixTimeSeconds().ToString()
+                new DateTimeOffset(now).ToUnixTimeSeconds().ToString(),
+                ClaimValueTypes.Integer64
             ),
             new Claim(
                 JwtRegisteredClaimNames.Exp,
-                new DateTimeOffset(now.AddSeconds(expiresIn)).ToUnixTimeSeconds().ToString()
+                new DateTimeOffset(now.AddSeconds(expiresIn)).ToUnixTimeSeconds().ToString(),
+                ClaimValueTypes.Integer64
             ),
             new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
         };