async function createCertificate()

in functions/source/lambda-self-signed-certificate/index.js [102:165]
49 lines of code
11 McCabe index (conditional complexity)

    async function createCertificate(resourceProperties, serverNamePrefix, newServerNameIdArray) {

        var selfsigned = require('selfsigned');
        const ssgenerate = util.promisify(selfsigned.generate);

        const _shortNames = {
            CN: 'commonName',
            C: 'countryName',
            L: 'localityName',
            ST: 'stateOrProvinceName',
            O: 'organizationName',
            OU: 'organizationalUnitName',
            E: 'emailAddress'
        };
        
        try {
            // Cast integer properties from passed string type back to integer 
            var attributes = toCamel(resourceProperties.Attributes)
            attributes.keySize = parseInt(attributes.keySize) || 1024
            
            // Parse the # of days the certificate should exists, defaulting to 365 if not provided
            attributes.days = parseInt(attributes.days) || 365

            // If an explicit 'ExpiresOn' YYYY-MM-DD is provided, validate that. Must be:
            // 1. Non-empty string
            // 2. In the form YYYY-MM-DD where MM is 01-12, DD is 01-31. Does not check for leap year
            // 3. Must be at least 1 day in the future.
            //
            if (resourceProperties.hasOwnProperty("ExpiresOn")) {
                attributes.days = 365
                if (resourceProperties["ExpiresOn"] !== "") {
                    if (resourceProperties["ExpiresOn"].match(/^\d{4}\-(0[1-9]|1[012])\-(0[1-9]|[12][0-9]|3[01])$/gm) == null) {
                        throw new Error("Invalid 'ExpiresOn' date format. Expected 'YYYY-MM-DD'");
                    }
                    // Calc number of days between new expiration and today (12:00midnight)
                    var curDate = new Date()
                    var expDate = new Date(resourceProperties["ExpiresOn"])
                    attributes.days = Math.round((expDate.setUTCHours(0,0,0)-curDate.setUTCHours(0,0,0)) / (1000*60*60*24))
                }
            }

            if (attributes.days <= 0) {
                throw new Error("'ExpiresOn' or 'Attributes.Days' must result in an expiration date at least one day in the future.");
            }

            // Iterate over provided options list with 'short names' and substitute back 'long names' removing
            // leading/trailing whitespace for the name and value
            var options = []
            for (var o of resourceProperties.Options.split(';')) {
                o = o.split('=')
                o[0] = o[0].trim()
                if (_shortNames[o[0]] != null) {
                    o[0] = _shortNames[o[0]]
                }
                options.push({
                    'name': o[0].toCamelCase(),
                    'value': o[1].trim()
                })
            }
            return await ssgenerate(options, attributes);
        } catch (err) {
            throw new Error("createCertificate() error: " + err.message);
        };
    }