Pre-request Postman script for sending Azure Service Bus REST requests using a SAS key

postman-sas-script.js

GistID: eedf956842966c41d47322f5b9e2a121

// Pre-request Postman script for sending Azure Service Bus REST requests using a SAS key

// https://docs.microsoft.com/en-us/rest/api/eventhub/Generate-SAS-token?redirectedfrom=MSDN#nodejs
// also https://gist.github.com/DinoChiesa/75796b27828cf8e15c91

const sasKey = postman.getEnvironmentVariable("SASKey"); 
const sasKeyName = postman.getEnvironmentVariable("SASKeyName");
const sbSubDomain = postman.getEnvironmentVariable("REST_SUBDOMAIN");
const topic = postman.getEnvironmentVariable("SB_TOPIC") || 'default-topic-name';
const subscription = postman.getEnvironmentVariable("SB_SUBSCRIPTION") || 'default-sub.default-topic-name';
const uri = `https://${sbSubDomain}.servicebus.windows.net/${topic}/subscriptions/${subscription}.${topic}/messages/head`;

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; 
    // hack to make signature utf8 encoded
    var signatureUTF8 = JSON.parse(JSON.stringify(signature));
    var hash = CryptoJS.HmacSHA256(signatureUTF8, sasKey); 
    var base64HashValue = CryptoJS.enc.Base64.stringify(hash);
    return 'SharedAccessSignature sr=' + encoded + '&sig=' +  
        encodeURIComponent(base64HashValue) + '&se=' + ttl + '&skn=' + saName; 
}

const token = createSharedAccessToken(uri, sasKeyName, sasKey);

postman.setEnvironmentVariable("SASToken", token);