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@jakeashcraft
Last active November 30, 2022 08:53
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Postman Pre-request Script used to automatically retrieve a new OAuth2 token when the token is expired
pm.expect(pm.globals.has('accessToken')).to.be.true;
const sdk = require('postman-collection');
const JWS_REGEX = /^[a-zA-Z0-9\-_]+?\.[a-zA-Z0-9\-_]+?\.([a-zA-Z0-9\-_]+)?$/;
const currentToken = pm.globals.get('accessToken').replace('Bearer ', '');
const path = pm.environment.get('url') + '/auth/token';
let expired = true;
if(currentToken && currentToken.length > 0) {
const parsed = jwsDecode(currentToken, null);
expired = isTokenExpired(parsed.payload.exp);
}
if(expired) {
const clientId = pm.globals.get('clientId');
const clientSecret = pm.globals.get('clientSecret');
// Create request
const tokenRequest = new sdk.Request({
url: path,
method: 'GET',
header: {
'content-type': 'application/json',
'lyve-client-id': clientId,
'lyve-client-secret': clientSecret
}
});
pm.sendRequest(tokenRequest, function(err, response) {
if(err) {
console.log(err);
}
const json = response.json();
pm.expect(json).to.an('object');
pm.test('response json has needed properties', function() {
pm.expect(json).to.have.own.property('access_token');
pm.expect(json).to.have.own.property('expires_in');
pm.expect(json).to.have.own.property('token_type');
const accessToken = json.access_token;
const tokenType = json.token_type;
const bearer = tokenType + ' ' + accessToken;
//console.log(`Bearer Value: ${bearer}`);
pm.globals.set('accessToken', bearer);
});
});
} else {
console.log('Token is still valid');
}
function padString(input) {
let segmentLength = 4;
let stringLength = input.length;
let diff = stringLength % segmentLength;
if (!diff) {
return input;
}
let position = stringLength;
let padLength = segmentLength - diff;
let paddedStringLength = stringLength + padLength;
let buffer = new Buffer(paddedStringLength);
buffer.write(input);
while (padLength--) {
buffer.write("=", position++);
}
return buffer.toString();
}
function decode(base64url, encoding = "utf8") {
return new Buffer(toBase64(base64url), "base64").toString(encoding);
}
function toBase64(base64url) {
base64url = base64url.toString();
return padString(base64url)
.replace(/\-/g, "+")
.replace(/_/g, "/");
}
function isObject(thing) {
return Object.prototype.toString.call(thing) === '[object Object]';
}
function safeJsonParse(thing) {
if (isObject(thing))
return thing;
try { return JSON.parse(thing); } catch (e) { return undefined; }
}
function headerFromJWS(jwsSig) {
var encodedHeader = jwsSig.split('.', 1)[0];
return safeJsonParse(decode(encodedHeader, 'binary'));
}
function isValidJws(string) {
return JWS_REGEX.test(string) && !!headerFromJWS(string);
}
function payloadFromJWS(jwsSig, encoding) {
encoding = encoding || 'utf8';
var payload = jwsSig.split('.')[1];
return decode(payload, encoding);
}
function signatureFromJWS(jwsSig) {
return jwsSig.split('.')[2];
}
function jwsDecode(jwsSig, opts) {
opts = opts || {};
if (!isValidJws(jwsSig))
return null;
var header = headerFromJWS(jwsSig);
if (!header)
return null;
var payload = payloadFromJWS(jwsSig);
if (header.typ === 'JWT' || opts.json)
payload = JSON.parse(payload, opts.encoding);
return {
header: header,
payload: payload,
signature: signatureFromJWS(jwsSig)
};
}
function isTokenExpired(exp) {
try {
return ((Date.now() / 1000) > exp);
} catch (error) {
return true;
}
}
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