fiddler.md

Fiddler Configuration - REST API Reference

To test the REST API using Fiddler, requests need to include the headers required for authentication. Here's how to configure Fiddler for testing the REST API, generating the authentication headers automatically:

1. Ensure that TLS 1.2 is an allowed protocol

   Open the HTTPS options (Tools->Options->HTTPS). Ensure that Decrypt HTTPS traffic is checked. Then in the list of protocols, add tls1.2 if not present.

2. Open "Fiddler Script Editor" or press Ctrl-R within Fiddler

3. Add the following code inside the Handlers class before the OnBeforeRequest function

   static function SignRequest(oSession: Session, credential: String, secret: String) {
       var utcNow = DateTimeOffset.UtcNow.ToString("r", System.Globalization.DateTimeFormatInfo.InvariantInfo);
       var contentHash = ComputeSHA256Hash(oSession.RequestBody);
       var stringToSign = oSession.RequestMethod.ToUpperInvariant() + "\n" + oSession.PathAndQuery + "\n" + utcNow +";" + oSession.hostname + ";" + contentHash;
       var signature = ComputeHMACHash(secret, stringToSign);
   
       oSession.oRequest.headers["x-ms-date"] = utcNow;
       oSession.oRequest.headers["x-ms-content-sha256"] = contentHash;
       oSession.oRequest.headers["Authorization"] = "HMAC-SHA256 Credential=" + credential + "&SignedHeaders=x-ms-date;host;x-ms-content-sha256&Signature=" + signature;
   }
   
   static function ComputeSHA256Hash(content: Byte[]) {
       var sha256 = System.Security.Cryptography.SHA256.Create();
       try {
           return Convert.ToBase64String(sha256.ComputeHash(content));
       }
       finally {
           sha256.Dispose();
       }
   }
   
   static function ComputeHMACHash(secret: String, content: String) {
       var hmac = new System.Security.Cryptography.HMACSHA256(Convert.FromBase64String(secret));
       try {
           return Convert.ToBase64String(hmac.ComputeHash(System.Text.Encoding.ASCII.GetBytes(content)));
       }
       finally {
           hmac.Dispose();
       }
   }

4. Add the following code at the end of the OnBeforeRequest function and update the access key as indicated by the TODO comment

   if (oSession.isFlagSet(SessionFlags.RequestGeneratedByFiddler) &&
       oSession.hostname.EndsWith(".azconfig.io", StringComparison.OrdinalIgnoreCase)) {
   
       // TODO: Replace the following placeholders with your access key
       var credential = "<Credential>"; // Id
       var secret = "<Secret>"; // Value
   
       SignRequest(oSession, credential, secret);
   }

5. Use Fiddler's Composer to generate and send a request