Node.js pipe decipher file Error: Unsupported state or unable to authenticate data

Question

I'm trying to encrypt/decrypt a file in stream with pipes. Encryption works, however when decrypting I get the error:

Error: Unsupported state or unable to authenticate data
at Decipheriv._flush (node:internal/crypto/cipher:160:29) at Decipheriv.final [as _final] (node:internal/streams/transform:112:25) at callFinal (node:internal/streams/writable:694:27) at prefinish (node:internal/streams/writable:719:7) at finishMaybe (node:internal/streams/writable:729:5) at Decipheriv.Writable.end (node:internal/streams/writable:631:5) at IOStream.onend (node:internal/streams/readable:693:10) at Object.onceWrapper (node:events:509:28) at IOStream.emit (node:events:402:35) at endReadableNT (node:internal/streams/readable:1343:12) Emitted 'error' event on Decipheriv instance at: at Decipheriv.onerror (node:internal/streams/readable:773:14) at Decipheriv.emit (node:events:390:28) at emitErrorNT (node:internal/streams/destroy:157:8) at emitErrorCloseNT (node:internal/streams/destroy:122:3) at processTicksAndRejections (node:internal/process/task_queues:83:21)

Code (last line produces the error):

const crypto = require('crypto');
const fs = require('fs');

const secret = crypto.randomBytes(32); 
const iv = crypto.randomBytes(16);

const cipher = crypto.createCipheriv('aes-256-gcm', secret, iv);
const decipher = crypto.createDecipheriv('aes-256-gcm', secret, iv);

fs.createReadStream('data.txt').pipe(cipher).
pipe(fs.createWriteStream('encrypted.txt'));

fs.createReadStream('encrypted.txt').pipe(decipher).
pipe(fs.createWriteStream('decrypted.txt'));

Because you start decrypting `encrypted.txt` before encrypting `data.txt` is completed. — lx1412, Dec 10 '21 at 05:23
How do I make sure the file is encrypted before I start decrypting it? — GeoCap, Dec 10 '21 at 15:35

score 0 · Accepted Answer · answered Dec 14 '21 at 19:44

It works like this, waiting for it to finish reading/encryping before starting writing/encrypting.

const crypto = require('crypto');
const fs = require('fs');

const secret = crypto.randomBytes(32);
const iv = crypto.randomBytes(16);

const cipher = crypto.createCipheriv('aes-256-gcm', secret, iv);
const decipher = crypto.createDecipheriv('aes-256-gcm', secret, iv);

fs.createReadStream('data.txt').pipe(cipher)
  .pipe(fs.createWriteStream('encrypted.txt'))
  .on('end', () => {
      fs.createReadStream('encrypted.txt')
        .pipe(decipher)
        .pipe(fs.createWriteStream('decrypted.txt'));
});

Node.js pipe decipher file Error: Unsupported state or unable to authenticate data

1 Answers1