Postman pre-request to add Veracode HMAC header

pre-request.js

var url = require('url');
var { Property } = require('postman-collection');

const id = pm.variables.get('veracodeApiKeyId');
const key = pm.variables.get('veracodeApiKeySecret');

const authorizationScheme = 'VERACODE-HMAC-SHA-256';
const requestVersion = "vcode_request_version_1";
const nonceSize = 16;

function computeHashHex(message, key_hex) {
    return CryptoJS.HmacSHA256(message, CryptoJS.enc.Hex.parse(key_hex)).toString(CryptoJS.enc.Hex);
}

function calulateDataSignature(key, nonceBytes, dateStamp, data) {
    let kNonce = computeHashHex(nonceBytes, key);
    let kDate = computeHashHex(dateStamp, kNonce);
    let kSig = computeHashHex(requestVersion, kDate);
    let kFinal = computeHashHex(data, kSig);
    return kFinal;
}

function newNonce() {
    return CryptoJS.lib.WordArray.random(nonceSize).toString().toUpperCase();
}

function toHexBinary(input) {
    return CryptoJS.enc.Hex.stringify(CryptoJS.enc.Utf8.parse(input));
}

function calculateVeracodeAuthHeader(httpMethod, requestUrl) {
    let urlExpanded = Property.replaceSubstitutions(requestUrl, pm.variables.toObject());
    let parsedUrl = url.parse(urlExpanded);
    let data = `id=${id}&host=${parsedUrl.hostname}&url=${parsedUrl.path}&method=${httpMethod}`;
    let dateStamp = Date.now().toString();
    let nonceBytes = newNonce(nonceSize);
    let dataSignature = calulateDataSignature(key, nonceBytes, dateStamp, data);
    let authorizationParam = `id=${id},ts=${dateStamp},nonce=${toHexBinary(nonceBytes)},sig=${dataSignature}`;
    let header = authorizationScheme + " " + authorizationParam;
    return header;
}

pm.request.headers.add({
    key: 'Authorization',
    value: calculateVeracodeAuthHeader(request['method'], request['url'])
});

Hi @ravikumarkd. The error tells you that the values have not been successfully retrieved in the script. Try temporarily replacing the pm.variables.get statements with literals to confirm this.

Any fix for this yet? Removing pm.variables.get gives a 401 error. As with id and key added, the error I receive is TypeError: Cannot read property 'length' of undefined.

@Fleurpot82 Not sure if you've fixed this yet. You need to specify the two variable values so they can be retrieved in lines 4&5:

• veracodeApiKeyId
• veracodeApiKeySecret

If they are zero length it complains when tryoing to validate them.

Thanks @markdowd, taken me a while to get back to this, I had the variables added, as below it worked fine when a pasted the values directly in. Deleted the variables in my project and re added and it works a treat. No idea what was wrong before as I'd created multiple collections in attempting it earlier!

Please note that we've published an official project and how-to for using Veracode HMAC in Postman here: https://github.com/veracode/veracode-postman

Contributions are welcome!