From the blog post:
> * Internet connection required (for now).
Also, cache manifest.
Show HN: Calculate MD5, SHA-1 in your browser using HTML5 and WebWorkers
21–26 of 26 posts
Re: Show HN: Calculate MD5, SHA-1 in your browser using HTML5 and WebWorkers
#22From the blog post: > * Internet connection required (for now). There's this thing called caching. ;) Also, cache manifest.
Yeah, the cache manifest will be the next feature for Browser Hash :)
Re: Show HN: Calculate MD5, SHA-1 in your browser using HTML5 and WebWorkers
#23Try http://www.hashsum.com
It's a Silverlight application I wrote years ago (as a warmup) and it does MD5, SHA1, SHA256, etc. and it is much faster than any Javascript or Flash implementation I've ever seen, including this one.
Apology for the very poor Google adsense placement and UI. Yeah it is embarrassing. It was my first introduction to web programming, Google Adsense, and UI, and I've moved on from it long ago. Needless to say I have learned a lot since then.
Hashsum can handle much bigger files than 10MB. In fact, for a file that small, you won't even notice that it did anything. Try something bigger, like a DVD-sized ISO (4.7GB) which will take about 1 or 2 minutes. All computation is done on the client side.
Anyone who claims Javascript is "as fast as C/C++" should at least try to beat Hashsum, which is only C# based.
Sadly, Microsoft is putting an end to this amazing technology, but that's another story.
Re: Show HN: Calculate MD5, SHA-1 in your browser using HTML5 and WebWorkers
#24Why would I want this? By this I mean, what's an end-to-end use case for it? In which a user wants a SHA hash of a file, uses this thing to get it, and then does something with the hash.
Browser-based upload, but with file-hash-based deduping to skip the upload if possible, à la Dropbox? (Not a use-case for this site, but one for in-browser file hashing)
Re: Show HN: Calculate MD5, SHA-1 in your browser using HTML5 and WebWorkers
#25Earlier quoted context omitted.
How would it be MITM'd? It all happens on your computer. Nothing travels over the network after the page is downloaded.
I think what xtacy means by MITM is that the javascript sent by the server might be MITM'd and altered to return a different value than the actual hash. But for instance, if I'm trying to SHA1 a Windows 8 iso (the kind which I imagine would be by far the most common use case - in which a cryptographically secure hash algorithm isn't even a prerequisite any checksum would do). It's not any worse than downloading the s…
No, it's worse than downloading the "sha1sum" app, because you only have to download "sha1sum" once. You can use a variety of out-of-band methods to verify the file that you can't reasonably or cost-effectively do with a website.
A website is essentially "installed" every time you visit it.
Re: Show HN: Calculate MD5, SHA-1 in your browser using HTML5 and WebWorkers
#26Earlier quoted context omitted.
You aren't worried that doing this via Javascript will make it insecure for that use? In almost the same manner as uploading your file to a server (simply to get the hash) would be?
I dont' really understand what you're saying here. Other services that calculate the digest of a file online require you to upload your file to the service/site where you don't know what they will do with it. With Browser Hash, not one bit of your file leaves your computer or travels over the network.
How do I know that my file is never leaving my computer? To verify that, I have to verify every line of Javascript code influencing that page, every time I use it, to make sure it isn't spiriting away my file contents or feeding bogus SHA fingerprint values back to me.