Stop using stream.pipe() (#1307)

stream.pipe() should rarely be used in practice because:

1. it can cause memory leaks, and
2. it does not propogate errors between streams

PartialPipe.pipeline() explicitly notes this and provides mitigations for it.

See:

* https://nodejs.org/api/stream.html#readablepipedestination-options
* https://stackoverflow.com/questions/58875655/whats-the-difference-between-pipe-and-pipeline-on-streams

lib/data/briefcase.js

@@ -7,7 +7,7 @@
 // including this file, may be copied, modified, propagated, or distributed
 // except according to the terms contained in the LICENSE file.
 
-const { Transform, pipeline } = require('stream');
+const { Transform } = require('stream');
 const hparser = require('htmlparser2');
 const { identity, last } = require('ramda');
 const csv = require('csv-stringify');
@@ -164,8 +164,8 @@ const processRow = (xml, instanceId, fields, header, selectValues) => new Promis
     }
   }, { xmlMode: true, decodeEntities: true });
 
-  if (typeof xml.pipe === 'function') {
-    pipeline(xml, parser, rejectIfError(reject));
+  if (xml instanceof PartialPipe) {
+    xml.with(parser).pipeline(rejectIfError(reject));
   } else {
     parser.write(xml);
     parser.end();

lib/data/client-audits.js

@@ -7,10 +7,11 @@
 // including this file, may be copied, modified, propagated, or distributed
 // except according to the terms contained in the LICENSE file.
 
-const { Transform, pipeline } = require('stream');
+const { Transform } = require('stream');
 const parse = require('csv-parse');
 const csv = require('csv-stringify');
 const sanitize = require('sanitize-filename');
+const { PartialPipe } = require('../util/stream');
 const { zipPart } = require('../util/zip');
 
 const headers = [ 'event', 'node', 'start', 'end', 'latitude', 'longitude', 'accuracy', 'old-value', 'new-value' ];
@@ -54,8 +55,8 @@ const parseClientAudits = (input) => {
 
   return new Promise((pass, fail) => {
     // feed either the stream or the buffer into the parser now.
-    if (input.pipe != null) {
-      pipeline(input, parser, (err) => { if (err != null) fail(err); });
+    if (input instanceof PartialPipe) {
+      input.with(parser).pipeline((err) => { if (err != null) fail(err); });
     } else {
       parser.write(input);
       parser.end();

lib/task/fs.js

@@ -19,6 +19,7 @@ const archiver = require('archiver');
 const yauzl = require('yauzl');
 const Problem = require('../util/problem');
 const { generateLocalCipherer, getLocalDecipherer } = require('../util/crypto');
+const { PartialPipe } = require('../util/stream');
 
 
 // given a directory containing files, a path to a tmpfile, and keyinfo data,
@@ -31,14 +32,15 @@ const { generateLocalCipherer, getLocalDecipherer } = require('../util/crypto');
 const encryptToArchive = (directory, tmpFilePath, keys) => {
   const outStream = createWriteStream(tmpFilePath);
   const zipStream = archiver('zip', { zlib: { level: 9 } });
-  zipStream.pipe(outStream);
 
   // create a cipher-generator for use below.
   const [ localkey, cipherer ] = generateLocalCipherer(keys);
   const local = { key: localkey, ivs: {} };
 
   // call up all files in the directory.
   return promisify(readdir)(directory).then((files) => new Promise((resolve, reject) => {
+    PartialPipe.of(zipStream, outStream).pipeline(reject);
+
     // stream each file into the zip, encrypting on the way in. clean up each
     // plaintext file as soon as we're done with them.
     // TODO: copypasted for now to lib/resources/backup
@@ -48,7 +50,7 @@ const encryptToArchive = (directory, tmpFilePath, keys) => {
       local.ivs[basename(file)] = iv.toString('base64');
 
       const readStream = createReadStream(filePath);
-      zipStream.append(readStream.pipe(cipher), { name: file });
+      zipStream.append(PartialPipe.of(readStream, cipher).pipeline(reject), { name: file });
       readStream.on('end', () => unlinkSync(filePath)); // sync to ensure completion.
     }
 
@@ -138,7 +140,7 @@ const decryptFromArchive = (archivePath, directory, passphrase = '') =>
                     if (completed === entries.length) resolve();
                   });
                   decipher.on('error', () => reject(Problem.user.undecryptable()));
-                  inStream.pipe(decipher).pipe(outStream);
+                  PartialPipe.of(inStream, decipher, outStream).pipeline(reject);
                 });
               });
             }, reject);

lib/util/crypto.js

@@ -15,6 +15,7 @@ const digest = require('digest-stream');
 const { createHash, randomBytes, generateKeyPair, pbkdf2, createPrivateKey, createPublicKey, createCipheriv, createDecipheriv, publicEncrypt, privateDecrypt } = require('crypto');
 const { RSA_NO_PADDING } = require('crypto').constants;
 const { Transform } = require('stream');
+const { PartialPipe } = require('./stream');
 const { unpadPkcs1OaepMgf1Sha256 } = require('./quarantine/oaep');
 const { unpadPkcs7 } = require('./quarantine/pkcs7');
 const { promisify } = require('util');
@@ -261,9 +262,9 @@ const streamSubmissionCleartext = (key, iv, input) => {
   });
 
   if (typeof input.pipe === 'function') {
-    return input.pipe(decipher).pipe(transform);
+    return PartialPipe.of(input, decipher, transform);
   } else {
-    const result = decipher.pipe(transform);
+    const result = PartialPipe.of(decipher, transform);
     decipher.write(input);
     decipher.end();
     return result;