Tag: node.js

I’m trying to put a video file to my bucket using a pre-signed url in angular4.

Node:

let s3 = new AWS.S3();
      s3.config.update({
        accessKeyId: process.env.VIDEO_ACCESS_KEY,
        secretAccessKey: process.env.VIDEO_SECRET_KEY
      })
      let videoId = await Video.createVideo()
      let params = {
        ACL: "public-read",
        Bucket: process.env.BUCKET_NAME,
        ContentType: 'video/mp4',
        Expires: 100,
        Key: req.jwt.username+"/"+videoId,
      }
      return s3.getSignedUrl('putObject', params, function (err, url) {
        if(!err) {
          console.log(url);
          res.status(200);
          res.json({
            url: url,
            reference: `${process.env.BUCKET_NAME}/${req.jwt.username}/${videoId}`,
            acl: params.ACL,
            bucket: params.Bucket,
            key: params.Key,
            contentType: params.ContentType,
          });
        } else {
          console.log(err);
          res.status(400);
          res.json({
            message: "Something went wrong"
          })
        }
      });

This successfully generates a url for me, and I try to use it in my post request in the front end.

Angular:

this.auth.fileUpload().subscribe((result) => {
        console.log(result["key"], result["acl"], result["bucket"], result["contentType"])
        if(!result["message"]) {
          let formData = new FormData();
          formData.append('file', file.files[0]);
          const httpOptions = {
            headers: new HttpHeaders({
              "Key": result["key"],
              "ACL": result["acl"],
              "Bucket": result["bucket"],
              "Content-Type": result["contentType"],
            })
          };
          this.http.post(result["url"], formData, httpOptions ).subscribe((response) => {
            console.log("response");
            console.log(response);
            let reference = `https://s3.amazonaws.com/${result["reference"]}`
            this.auth.makeVideo(result["reference"]).subscribe((result) => {
              console.log(result);
            });
          }, (error) => {
            console.log("error");
            console.log(error);
          })

But this generates an error.

SignatureDoesNotMatch
The request signature we calculated does not match the signature you provided. Check your key and signing method

Here’s the URL that I generate

https://MY_BUCKET_HERE.s3.amazonaws.com/admin/87f314f1-9f2e-462e-84ff-25cba958ac50?AWSAccessKeyId=MY_ACCESS_KEY_HERE&Content-Type=video%2Fmp4&Expires=1520368428&Signature=Ks0wfzGyXmBTiAxGkHNgcYblpX8%3D&x-amz-acl=public-read

I’m pretty sure I’m just making a simple mistake, but I can’t figure it out for the life of me. Do I need to do something with my headers? Do I need to change the way I read the file for the post? I’ve gotten it to work with a public bucket with FormData and a simple post request with no headers, but now that I’m working with Policies and a private bucket, my understanding is much less. What am I doing wrong?

Solution:

If you generate a pre-signed URL for PutObject then you should use the HTTP PUT method to upload your file to that pre-signed URL. The POST method won’t work (it’s designed for browser uploads).

Also, don’t supply HTTP headers when you invoke the PUT. They should be supplied when generating the pre-signed URL, but not when using the pre-signed URL.