[Web Previewer] Component does not preview files from S3 bucket except image

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Swatantra Kumar

Champion

Solved

[Web Previewer] Component does not preview files from S3 bucket except image

Question

Forge

OutSystems installation: On-Premise

Platform version: O 11.0.424.0

File Storage: Amazon S3

In our On-Premise version of OutSystems I'm consuming the REST API from S3 to get the non-public file URL along with security token, long expiry time and other amazon parameters.

The URL I receive is accessible on browsers, but when supplied to Web Previewer component, it throws error (can not preview the file).

It works with image (png/jpeg), but not with other types e.g. docx, xlsx, pptx, pdf.

Making the files public it starts showing in the preview panel. This eliminates the thought of Firewall issue.

Also, if browsers can open the non-public file provided the security token then what's causing issue with component? Any pointer?

06 Aug 2019

Swatantra Kumar

Champion

Solution

Ah, I found the issue and made it work.

For future readers,

I had my S3 hosted Original Public File URL = https://bucketputswatantra.s3.eu-central-1.amazonaws.com/26011983.pdf

Same file after making it Private comes with additional AuthorizationQueryParameters.
S3 Query-string authentication version 4 requires below parameters.
- X-Amz-Algorithm,
- X-Amz-Credential,
- X-Amz-Signature,
- X-Amz-Date,
- X-Amz-SignedHeaders, and
- X-Amz-Expires
  So, my new Private File URL = https://bucketputswatantra.s3.eu-central-1.amazonaws.com/26011983.pdf?X-Amz-Expires=604800&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIUKRHHK5GXNGVHDA/20190826/eu-central-1/s3/aws4_request&X-Amz-Date=20190808T133519Z&X-Amz-SignedHeaders=host&X-Amz-Signature=466647bb4407d7cf123ee9a2a72057e19218f039f3c2baa5934fd1cd686099da

Supplying it to WebPreviewer resulted as error (as mentioned in the question)
- It made an URL https://docs.google.com/viewerng/viewer?url=https://bucketputswatantra.s3.eu-central-1.amazonaws.com/26011983.pdf?X-Amz-Expires%3D604800&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIUKRHHK5GXNGVHDA/20190826/eu-central-1/s3/aws4_request&X-Amz-Date=20190808T133519Z&X-Amz-SignedHeaders=host&X-Amz-Signature=466647bb4407d7cf123ee9a2a72057e19218f039f3c2baa5934fd1cd686099da
- The above URL is not well-formed, see two ? additionally multiple & which is not the accepted parameter for docs.google.

Google doc viewer expects below parameters as I read in manual
- url: document url (encode the url if it containes parameters, etc.)
- hl: language (ex: en, hn etc.)
- embedded: embededable link, value true/false [MUST be used true to show]

Docs Manual made my day, I encoded the URL in JS function
encodeURIComponent() encodes a URI component with special characters
Resulting as encoded URL = https%3A%2F%2Fbucketputswatantra.s3.eu-central-1.amazonaws.com%2F26011983.pdf%3FX-Amz-Expires%3D604800%26X-Amz-Algorithm%3DAWS4-HMAC-SHA256%26X-Amz-Credential%3DAKIAIUKRHHK5GXNGVHDA%2F20190826%2Feu-central-1%2Fs3%2Faws4_request%26X-Amz-Date%3D20190808T133519Z%26X-Amz-SignedHeaders%3Dhost%26X-Amz-Signature%3D466647bb4407d7cf123ee9a2a72057e19218f039f3c2baa5934fd1cd686099da

Supplying new encoded URL to google viewer worked like charm
https://docs.google.com/viewerng/viewer?url=https%3A%2F%2Fbucketputswatantra.s3.eu-central-1.amazonaws.com%2F26011983.pdf%3FX-Amz-Expires%3D604800%26X-Amz-Algorithm%3DAWS4-HMAC-SHA256%26X-Amz-Credential%3DAKIAIUKRHHK5GXNGVHDA%2F20190826%2Feu-central-1%2Fs3%2Faws4_request%26X-Amz-Date%3D20190808T133519Z%26X-Amz-SignedHeaders%3Dhost%26X-Amz-Signature%3D466647bb4407d7cf123ee9a2a72057e19218f039f3c2baa5934fd1cd686099da

N.B: I've changed few parameter values to safeguard content.

08 Aug 2019

Tony Wang

Hi, Swatantra

Maybe you can try S3 Presigned URL.

It allows anonymous users to access the assigned object stored in a bucket

Sincerely

Tony

03 Jun 2020

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