feat: Add region to access token

src/Twilio/JWT/AccessToken/Token.cs

@@ -13,6 +13,7 @@ public class Token : BaseJwt
         private readonly string _identity;
         private readonly DateTime? _nbf;
         private readonly HashSet<IGrant> _grants;
+        private readonly string _region;
 
         /// <summary>
         /// Create a new Access Token
@@ -24,14 +25,16 @@ public class Token : BaseJwt
         /// <param name="expiration">Token expiration</param>
         /// <param name="nbf">Token nbf</param>
         /// <param name="grants">Token grants</param>
+        /// <param name="region">Token region</param>
         public Token(
             string accountSid,
             string signingKeySid,
             string secret,
             string identity = null,
             DateTime? expiration = null,
             DateTime? nbf = null,
-            HashSet<IGrant> grants = null
+            HashSet<IGrant> grants = null,
+            string region = null
         ) : base(secret, signingKeySid, expiration.HasValue ? expiration.Value : DateTime.UtcNow.AddSeconds(3600))
         {
             var now = BaseJwt.ConvertToUnixTimestamp(DateTime.UtcNow);
@@ -40,6 +43,7 @@ public Token(
             this._identity = identity;
             this._nbf = nbf;
             this._grants = grants;
+            this._region = region;
         }
 
         /// <summary>
@@ -75,14 +79,32 @@ public override DateTime? Nbf
             }
         }
 
+        /// <summary>
+        /// The region associated with this account
+        /// </summary>
+        public string Region
+        {
+            get
+            {
+                return _region;
+            }
+        }
+
         /// <summary>
         /// Headers for an Access Token
         /// </summary>
         public override Dictionary<string, object> Headers
         {
             get
             {
-                return new Dictionary<string, object> { { "cty", "twilio-fpa;v=1" } };
+                var headers = new Dictionary<string, object> { { "cty", "twilio-fpa;v=1" } };
+
+                if (_region != null)
+                {
+                    headers.Add("twr", _region);
+                }
+
+                return headers;
             }
         }
 

test/Twilio.Test/Jwt/AccessToken/AccessTokenTest.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections;
 using System.Collections.Generic;
 using NUnit.Framework;
 using Twilio.Jwt;
@@ -16,16 +17,9 @@ public TestToken(
             string identity = null,
             DateTime? expiration = null,
             DateTime? nbf = null,
-            HashSet<IGrant> grants = null
-        ) : base(accountSid, signingKeySid, secret, identity, expiration, nbf, grants) {}
-
-        public override Dictionary<string, object> Headers
-        {
-            get
-            {
-                return new Dictionary<string, object>();
-            }
-        }
+            HashSet<IGrant> grants = null,
+            string region = null
+        ) : base(accountSid, signingKeySid, secret, identity, expiration, nbf, grants, region) {}
     }
 
     [TestFixture]
@@ -54,6 +48,41 @@ public void TestBuildToken()
             Assert.AreEqual("{}", payload["grants"].ToString());
         }
 
+        [Test]
+        public void TestHaveRegion()
+        {
+            var now = DateTime.UtcNow;
+            var token = new TestToken("AC456", "SK123", Secret, region: "foo").ToJwt();
+            Assert.IsNotNull(token);
+            Assert.IsNotEmpty(token);
+
+            var decoded = new DecodedJwt(token, Secret);
+            var header = decoded.Header;
+            Assert.IsNotNull(header);
+            Assert.AreEqual("twilio-fpa;v=1", header["cty"]);
+            Assert.AreEqual("foo", header["twr"]);
+        }
+
+        [Test]
+        public void TestEmptyRegion()
+        {
+            var now = DateTime.UtcNow;
+            var token = new TestToken("AC456", "SK123", Secret).ToJwt();
+            Assert.IsNotNull(token);
+            Assert.IsNotEmpty(token);
+
+            var decoded = new DecodedJwt(token, Secret);
+            var header = decoded.Header;
+            Assert.IsNotNull(header);
+            Assert.AreEqual("twilio-fpa;v=1", header["cty"]);
+
+            try {
+                var twr = header["twr"];
+                Assert.Fail();
+            } catch (KeyNotFoundException) {
+                // Pass
+            }
+        }
 
         [Test]
         public void TestHaveNbf()

test/Twilio.Test/Jwt/DecodedJwt.cs

@@ -1,50 +1,72 @@
-#if !NET35
-using System.IdentityModel.Tokens.Jwt;
-#else
+using System;
 using System.Collections.Generic;
-#endif
-
-using System;
+using System.Security.Cryptography;
+using System.Text;
 using Newtonsoft.Json;
 
 namespace Twilio.Tests.Jwt
 {
     class DecodedJwt
     {
-#if !NET35
+        private static byte[] Base64UrlDecode(string input) => Convert.FromBase64String(UrlDecode(input));
 
-        public JwtPayload Payload
+        private static string UrlDecode(string input)
         {
-            get
+            var output = input;
+            output = output.Replace('-', '+'); // 62nd char of encoding
+            output = output.Replace('_', '/'); // 63rd char of encoding
+
+            // Pad with trailing '='s
+            switch (output.Length % 4)
             {
-                return token.Payload;
+                case 0:
+                    break; // No pad chars in this case
+                case 2:
+                    output += "==";
+                    break; // Two pad chars
+                case 3:
+                    output += "=";
+                    break; // One pad char
+                default:
+                    throw new Exception($"Illegal base-64 string: '{input}'.");
             }
+
+            return output;
         }
 
-        private readonly JwtSecurityToken token;
+        private static IDictionary<string, object> DecodeJwtPart(string part)
+        {
+            var bytes = Base64UrlDecode(part);
+            var json = Encoding.UTF8.GetString(bytes);
+            var data = JsonConvert.DeserializeObject<Dictionary<string, object>>(json);
 
-        public DecodedJwt(string jwt, string secret)
+            return data;
+        }
+
+        public IDictionary<string, object> Header
         {
-            token = new JwtSecurityToken(jwt);
+            get
+            {
+                return _header;
+            }
         }
 
-#else
         public IDictionary<string, object> Payload
         {
             get
             {
-                return JsonConvert.DeserializeObject<Dictionary<string, object>>(token);
+                return _payload;
             }
         }
 
-        private readonly string token;
+        private readonly IDictionary<string, object> _header;
+        private readonly IDictionary<string, object> _payload;
 
         public DecodedJwt(string jwt, string secret)
         {
-            token = JWT.JsonWebToken.Decode(jwt, secret);
+            var parts = jwt.Split('.');
+            _header = DecodeJwtPart(parts[0]);
+            _payload = DecodeJwtPart(parts[1]);
         }
-
-#endif
-
     }
 }