How to create SAS token in Postman to use with Service bus?

Question

Base on this Microsoft documentation: https://learn.microsoft.com/en-us/rest/api/eventhub/generate-sas-token

the code for nodejs is:

function createSharedAccessToken(uri, saName, saKey) { 
if (!uri || !saName || !saKey) { 
        throw "Missing required parameter"; 
    } 
var encoded = encodeURIComponent(uri); 
var now = new Date(); 
var week = 60*60*24*7;
var ttl = Math.round(now.getTime() / 1000) + week;
var signature = encoded + '\n' + ttl; 
var signatureUTF8 = utf8.encode(signature); 
var hash = crypto.createHmac('sha256', saKey).update(signatureUTF8).digest('base64'); 
return 'SharedAccessSignature sr=' + encoded + '&sig=' +  
    encodeURIComponent(hash) + '&se=' + ttl + '&skn=' + saName; 
 }

And I was trying it on Postman, in case anyone need help with it. This is the code that works for me under the Pre-request Script using Postman

var namespace = pm.collectionVariables.get("serviceNamespace");
var uri = "https://" + namespace + ".servicebus.windows.net/adfTest/messages";
var saName = pm.collectionVariables.get("SharedAccessKeyName");
var saKey = pm.collectionVariables.get("SharedAccessKeySend");

var sasToken = createSharedAccessToken(uri, saName, saKey);

console.log(sasToken);
pm.collectionVariables.set("SasToken", sasToken);

function createSharedAccessToken(uri, saName, saKey) { 
    if (!uri || !saName || !saKey) { 
            throw "Missing required parameter"; 
        } 
    var encoded = encodeURIComponent(uri).toLowerCase(); 
    var now = new Date(); 
    var week = 60*60*24*7;
    var ttl = Math.round(now.getTime() / 1000) + week;
    var signature = encoded + '\n' + ttl;     
    var hash = CryptoJS.HmacSHA256(signature, saKey);
    var hashInBase64 = CryptoJS.enc.Base64.stringify(hash);
    return 'SharedAccessSignature sr=' + encoded + '&sig=' +  
        encodeURIComponent(hashInBase64) + '&se=' + ttl + '&skn=' + saName; 
}

Answer 1

1. Under you collection create the variables:

Get the values from Azure portal - Service bus serviceNamespace, SharedAccessKey, SharedAccessKeyName

2. Add the code under Pre-request Script

   var namespace =      pm.collectionVariables.get("serviceNamespace");
   var uri = "https://" + namespace + ".servicebus.windows.net/adfTest/messages";
   var saName = pm.collectionVariables.get("SharedAccessKeyName");
   var saKey = pm.collectionVariables.get("SharedAccessKeySend");
   
   var sasToken = createSharedAccessToken(uri, saName, saKey);
   
   console.log(sasToken);
   pm.collectionVariables.set("SasToken", sasToken);
   
   function createSharedAccessToken(uri, saName, saKey) { 
       if (!uri || !saName || !saKey) { 
               throw "Missing required parameter"; 
           } 
       var encoded = encodeURIComponent(uri).toLowerCase(); 
       var now = new Date(); 
       var week = 60*60*24*7;
       var ttl = Math.round(now.getTime() / 1000) + week;
       var signature = encoded + '\n' + ttl;     
       var hash = CryptoJS.HmacSHA256(signature, saKey);
       var hashInBase64 = CryptoJS.enc.Base64.stringify(hash);
       return 'SharedAccessSignature sr=' + encoded + '&sig=' +  
           encodeURIComponent(hashInBase64) + '&se=' + ttl + '&skn=' + saName; 
   }
   

Note: the adfTest part is the name of the topic, it should be replace by your topic name

var uri = "https://" + namespace + ".servicebus.windows.net/adfTest/messages";

• Under Authorization use the sasToken variable:

• Select API key from the dropdown menu.

• Key = Authorization

• Value = {{SasToken}} <-- this is the variable name

• Add to = Header

4. Create a post:

These are the requirements for the post

     POST https://<yournamespace>.servicebus.windows.net/<yourentity>/messages
    Content-Type: application/json
    Authorization: SharedAccessSignature sr=https%3A%2F%2F<yournamespace>.servicebus.windows.net%2F<yourentity>&sig=<yoursignature from code above>&se=1438205742&skn=KeyName
    ContentType: application/atom+xml;type=entry;charset=utf-8

The URL should look like: https://.servicebus.windows.net//messages

under Authorization inherit auth from parent:

this is gonna add Authorization header with the SAS token generated by the pre-request Script under the collection

Add the other headers:

6. Put the message in the body:

This could be any json data