I'm using ldap3.
I can connect and read all attributes without any issue, but I don't know how to display the photo of the attribute thumbnailPhoto.
If I print(conn.entries[0].thumbnailPhoto) I get a bunch of binary values like b'\xff\xd8\xff\xe0\x00\x10JFIF.....'.
I have to display it on a bottle web page. So I have to put this value in a jpeg or png file.
How can I do that?
The easiest way is to save the raw byte value in a file and open it with a picture editor. The photo is probably a jpeg, but it can be in any format.
Have a look at my answer at Display thumbnailPhoto from Active Directory in PHP. It's especially for PHP but the concept is the same for Python.
basically it's about either using the base64 encoded raw-data as data-stream or actually using a temporary file that is serverd (or used to determine the mime-type)
Related
I want to convert any documents or image or text file into PDF for all the OS.
I tried the approach with node-msoffice-pdf, and its working fine for Windows OS but not working in other OS.
Question:
How to convert docs, images, textfile to pdf in nodejs?
I used wkhtmltopdf from years to manage pdf conversion.
https://github.com/devongovett/node-wkhtmltopdf
You can either render an html file and pass it to the module, or render a pdf directly from an url.
If fidelity/conversion quality is important to you, for Word documents (doc/docx) you could try our freemium https://www.npmjs.com/package/#nativedocuments/docx-wasm which will perform the conversion locally (ie where node is running), without the need to LibreOffice etc.
I'm building a project where people can upload files, I would like to then display those files in a browser where people can interact with them (vote, comment etc)
However, this means I need to programatically build the html depending on the format of the video or image. Is there a way to feed a file (or filename) into a library, and determine whether I need to display it in a video element or an image element? Even a list of video formats vs image formats would help but I haven't seen anything in regards to that.
No module can reliably determine the file type. The user could either change the extension or even the magic number of the file to obfuscate it. The only reliable way it to try to pass file to some image / video transcoder to let it decide or error out if the format is invalid. This way you know you are working with known formats since all files are transcoded to your specific extensions. That could be mp4 or png. I recommend using handbrake for videos and sharp for images. Leaving the NPM links down below:
https://www.npmjs.com/package/handbrake-js
https://www.npmjs.com/package/sharp
Stuck in this weird situation at work. I have .doc files I'm parsing with Node.JS. They have photos in them that are .emf I want to display in my web app. I have no issue getting the emf file out of the word doc, but I can't figure out how to display it on a webpage. Simply embedding as is didn't work. I tried to find a utility to convert them automatically but with no luck. I thought of converting them myself but can't find any tecnhical info on the .emf file.
Any suggestions?
EMF (WMF) are the SVG like formats of the 1990's.
I can't give you the full solution in this space but checkout this thread that uses Apache Batik
If you don't want to build it yourself perhaps try the paid version of converters
If you can't afford I would recommend to host the Batik and make a service endpoint and make calls to generate the desired format from EMF. It may turn out actually faster.
Imagine an environment in which users can upload images to a website by either uploading it from their pc or referring to a remote url.
As part of some security checks I'd like to make sure that the referenced object is indeed an image.
In the case of a remote-url, I of course check the content-type, but this isn't bullet-proof.
I figured I could use ImageMagick to do the task. Perhaps executing the ImageMagick.identify() method and if no error is returned and returned type is either JPG|GIF|,etc. the content is an image. (In a quick check I noticed that TXT files are identified correctly as well, so I have to blacklist these)
Is there any better way in doing this?
You could probably simply load the image via ImageMagick's appropriate function for your language of choice. If the image isn't formatted properly (in terms of internal formatting, not its aesthetic properties, that is), I would expect ImageMagick to refuse to load it and report an error. In PHP, for example, readImage returns false if the image fails to load.
Alternatively, you could read the first few hundred bytes of the file and determine if the expected image file format headers are present; e.g., "GIF89" etc.
These checks may backfire, if your image is in a compressable format (PNG, GIF) and it is constructed in a way similar to a zip bomb https://en.wikipedia.org/wiki/Zip_bomb
Some examples at ftp://ftp.aerasec.de/pub/advisories/decompressionbombs/pictures/ (nothing special about that site, I just googled decompression bombs)
Another related issue is that formats like SVG are in fact XML and some image processing tools are prone to a variant of "billion laughs" attack https://en.wikipedia.org/wiki/Billion_laughs
You should not store the original file. The generally recommended approach is to always re-process the image and convert it to an entirely new file. There have been vulnerabilites exploited inside valid image files (see GIFAR), so checking for this would have been useless.
Never expose your visitors to an image file that you have not written out yourself and for which you did not choose the file name yourself.
I have a table with documents saved some of them in pdf, some of them image.
I want to create a web app, to show the images (that can be either pdf, either jpg) in the same control.
I can manage to see pdf, if I set the Response.ContentType = "application/pdf" or image if I set "application/jpg". But the problem is that how can I get the file type, having only the stream saved into the database? Does it have the stream the file type information in it?
Thanks.
No, a stream does not have a content type associated with it. If you had the original filename, you could attempt to derive the content type from that, but it wouldn't be foolproof.
Many file formats have a series of "magic bytes" that allow you to detect what (might) be in the file. PDF, for example, begins with the bytes "%PDF" (note: I'm not an expert on PDF, and there may be situations where that is not true).
If you have no other option, you could attempt to parse the file using various libraries until you found one that worked (System.Drawing.Image.FromStream(), iTextSharp, etc).