AWS CloudFront

cloudfront.service.ts

import {Injectable} from '@nestjs/common';
import CloudFront from "aws-sdk/clients/cloudfront";
import AWS from "aws-sdk";
import {Signer} from "aws-sdk/lib/cloudfront/signer";
import * as fs from 'fs';

@Injectable()
export class CloudfrontService {
    cloudFront: CloudFront;
    keyPairId: string;
    privateKey: string;

    constructor() {
        this.keyPairId = process.env.AWS_CLOUDFRONT_ACCESSKEY_ID || '';
        this.privateKey = fs.readFileSync(`./keys/pk-${this.keyPairId}.pem`).toString();
        this.cloudFront = new CloudFront();
    }

    // Get specific signed url
    getSignedUrl(url: string): Promise<string> {
        return new Promise((resolve, reject) => {
            const expiry = Math.floor(Date.now() / 1000) + 120; // 2 minutes
            const signer = new AWS.CloudFront.Signer(this.keyPairId, this.privateKey);
            const options = {url: url, expires: expiry};
            signer.getSignedUrl(options, function (err, data) {
                if (err) {
                    reject(err);
                } else {
                    resolve(data);
                }
            });
        });
    }

    // Get specific signed cookies
    getSignedCookie(domain: string): Promise<Signer.CustomPolicy> {
        return new Promise((resolve, reject) => {
            const expiry = Math.floor(Date.now() / 1000) + 86400; // 1day
            const policy = {
                'Statement': [{
                    'Resource': "https://" + domain + "/*",
                    'Condition': {
                        'DateLessThan': {'AWS:EpochTime': expiry}
                    }
                }]
            };
            const policyString = JSON.stringify(policy);
            const signer = new AWS.CloudFront.Signer(this.keyPairId, this.privateKey);
            const options = {url: "https://" + domain, policy: policyString};
            signer.getSignedCookie(options, function (err, data) {
                if (err) {
                    reject(err);
                } else {
                    resolve(data);
                }
            });
        });
    }
}