I can access jwt inside my web api action by accessing it's Autorization Header
string jwt=Request.Headers.Authorization.ToString();
string jwtArray = jwt.split('.');
//Now i want to convert it's payload into Key value pair.
The payload is in jwtArray[1]. Can anyone suggest how this can be converted into a KVP. I am assuming the JWT is Base64 encoded by the look of it.
Try this
var parts = token.Split('.');
string partToConvert = parts[1];
partToConvert = partToConvert.Replace('-', '+');
partToConvert = partToConvert.Replace('_', '/');
switch (partToConvert.Length % 4)
{
case 0:
break;
case 2:
partToConvert += "==";
break;
case 3:
partToConvert += "=";
break;
}
var partAsBytes = Convert.FromBase64String(partToConvert);
var partAsUTF8String = Encoding.UTF8.GetString(partAsBytes, 0, partAsBytes.Count());
// You would need Json .NET for the below
var jwt = JObject.Parse(partAsUTF8String);
var dictionary = JsonConvert.DeserializeObject<Dictionary<string, object>>(jwt.ToString());
For a cleaner approach to this, Here's a helper class based on a couple of brilliant answers.
public static class StringExtensions
{
/// <summary>
/// Convert a normal string to base64
/// </summary>
/// <param name="text">Original String</param>
/// <returns></returns>
/// <remarks>
/// Original Source: https://stackoverflow.com/a/60738564/8058709
/// </remarks>
public static string EncodeToBase64(this string text)
{
return Convert.ToBase64String(Encoding.UTF8.GetBytes(text))
.TrimEnd('=').Replace('+', '-')
.Replace('/', '_');
}
/// <summary>
/// Convert a base64 string to a normal one
/// </summary>
/// <param name="payload">Base64 string</param>
/// <returns>A normal string</returns>
/// <remarks>
/// Original Source: https://stackoverflow.com/a/60738564/8058709
/// </remarks>
public static string DecodeFromBase64(this string payload)
{
payload = payload.Replace('_', '/').Replace('-', '+');
switch (payload.Length % 4)
{
case 2:
payload += "==";
break;
case 3:
payload += "=";
break;
}
return Encoding.UTF8.GetString(Convert.FromBase64String(payload));
}
/// <summary>
/// Decode a JWT payload to a dictionary
/// </summary>
/// <param name="jwt">JWT payload</param>
/// <returns>
/// A dictionary representation of the jwt string
/// </returns>
/// <remarks>
/// Inspiration: https://stackoverflow.com/a/31878953/8058709
/// </remarks>
public static IDictionary<string, object> DecodeJwt(this string jwt)
{
string[] chunks = jwt.Split('.');
string data = DecodeFromBase64(chunks.ElementAtOrDefault(1));
return JsonConvert.DeserializeObject<Dictionary<string, object>>(data);
}
}
