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Blob: Additional bytes added to binary data when retrieving from store

See original GitHub issue

Which service(blob, file, queue, table) does this issue concern?


Which version of the SDK was used?


What’s the Node.js/Browser version?


What problem was encountered?

When retrieving binary data (PNG images in this case) the following error is thrown:

Error: An incorrect number of bytes was read from the connection. The connection may have been closed.
    at BlobService._validateLengthAndMD5 (./node_modules/azure-storage/lib/services/blob/blobservice.core.js:5422:28)
    at processResponseCallback (./node_modules/azure-storage/lib/services/blob/blobservice.core.js:1879:12)
    at Request.processResponseCallback [as _callback] (./node_modules/azure-storage/lib/common/services/storageserviceclient.js:329:13)
    at Request.self.callback (./node_modules/request/request.js:185:22)
    at Request.emit (events.js:182:13)
    at Request.<anonymous> (./node_modules/request/request.js:1161:10)
    at Request.emit (events.js:182:13)
    at IncomingMessage.<anonymous> (./node_modules/request/request.js:1083:12)
    at Object.onceWrapper (events.js:273:13)
    at IncomingMessage.emit (events.js:187:15)

Steps to reproduce the issue?

const { promisify } = require('utils');
const { createBlobService } = require('azure-storage');

const blobSvc = createBlobService();
const createBlob = promisify(blobSvc.createBlockBlobFromText.bind(blobSvc));
const getBlob = promisify(blobSvc.getBlobToText.bind(blobSvc));

async function example() {
    await createBlob('container', 'test.png', Buffer.from([137, 80, 78, 71, 13, 10, 26, 10]), {
        contentSettings: {
            contentType: 'application/json',
    await getBlob('container', 'test.png'); // this will throw

Have you found a mitigation/solution?

Use getBlobToStream instead. I understand that the blob is not text data, but if we can send and successfully store buffers representing non-text based data, why can we not retrieve it with the corresponding API. The response from the server seems to be corrupted in the server side as the text data gets 2 additional bytes added to it.

My debugging has found that the data response appears to be correct, but it has some additional trailing whitespace, which adds 2 additional bytes causing the length comparison to fail. Is there a better way to get a Buffer returned?

Issue Analytics

  • State:closed
  • Created 4 years ago
  • Comments:8 (4 by maintainers)

github_iconTop GitHub Comments

dhensbycommented, Aug 16, 2019

I am using getBlobToStream but still getting the same error mentioned above.

This issue is specifically about getBlobToText, I suggest you open an new issue rather than tag onto a closed one

jiacfancommented, Aug 16, 2019

Hi, @GagandeepBajwa

Welcome reaching us! Would you please let me know how you upload the images?

Thanks, Jiachen

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