encrypt-pdf

encrypt-pdf.ts

/* eslint-disable no-await-in-loop */

import { writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import type { Readable } from "node:stream";

import { encrypt, type EncryptOptions } from "node-qpdf2";

import { getFileFromS3, parseS3Uri, uploadFilePathToS3 } from "./aws.s3.js";
import notify from "./aws.sqs.js";
import { guid } from "./guid.js";

/** Writes a Readable to a File in tmpdir() */
export const writeTemporaryFile = async (file: Readable): Promise<string> => {
  const filePath = join(tmpdir(), `${guid()}.pdf`);
  // eslint-disable-next-line security/detect-non-literal-fs-filename
  await writeFile(filePath, file);
  return filePath;
};

/** Returns the local encrypted file path */
export const encryptFile = async (
  input: string,
  userPassword = "1234",
): Promise<string> => {
  const options: EncryptOptions = {
    input,
    output: join(tmpdir(), `${guid()}.pdf`),
    password: userPassword,
  };
  await encrypt(options);
  return options.output as string;
};

/* c8 ignore start */
export default async (event: AWSLambda.SQSEvent) => {
  const allPromises = [];
  // First, let's loop through the sqs events
  for (const record of event.Records) {
    // Get the body of the record
    const json = JSON.parse(record.body);
    const payloads =
      // @ts-expect-error I want to iterate
      typeof json[Symbol.iterator] === "function"
        ? (json)
        : ([json]);

    // For each payload in the json body
    for (const payload of payloads) {
      /** The URI of the file to encrypt */
      let filePath = payload.encrypt.url;

      // If there is a password specified, encrypt the file
      if (payload.encrypt.password) {
        // Parse the s3 uri in order to get the bucket and file
        const { bucket, key } = parseS3Uri(payload.encrypt.url);
        /** The unencrypted Readable PDF stream */
        const unencryptedFile = getFileFromS3(bucket as string, key as string);
        /** The location of the unencrypted pdf file. */
        const unencryptedTemporaryFilePath = writeTemporaryFile(
          await unencryptedFile,
        );
        /** The local encrypted pdf file path */
        const encryptedFilePath = encryptFile(
          await unencryptedTemporaryFilePath,
          payload.encrypt.password,
        );
        /** The encrypted pdf URI in S3 */
        const encryptedURI = uploadFilePathToS3(await encryptedFilePath, false);
        filePath = await encryptedURI;
      }

      // Send an email to the FO
      allPromises.push(sendEmailFunction(payload, filePath));
    }
  }
  await Promise.all(allPromises);
};
/* c8 ignore end */