PHP - Hash contents of uploaded file

Question

I would like to hash the contents of an uploaded file in MD5. The file will not be saved locally so it only exists in a tmp directory.

How can I do this? Thanks.

Solution 1

You can use md5_file() or sha1_file() function. For example, if your post variable is filevar:

$myhash = md5_file($_FILES['filevar']['tmp_name']);

Solution 2

You can use md5_file(), even on your temporary file.

Solution 3

MD5() for string and md5_file() for files

Comments

[A Clockwork Orange]

Yes. MD5 is fine. It's just for debugging right now.

[gideon]

think there is md5_file()? See this question Also you may want to use a stronger hash like SHA that will have less possibilities of collisions.

[gideon]

See the second answer here. : stackoverflow.com/questions/770900/…

[A Clockwork Orange]

This is just for debugging. Only up to 3 files will be stored so I don't need to worry about collisions. I different hashing function will be used in the final, I just need to make sure the rest of it works.

[65Fbef05]

Just as a note, hashing a file in md5 does not provide storage ability - its use is more for file verification. You cannot 'decode' the md5 hash to create a usable file.

[A Clockwork Orange]

65Fbef05, Thank you but I understand how hashing functions work :]

[nerkn]

I'm late :) +1 for exactly same answer