bah.crypto feature request
BlitzMax Forums/Brucey's Modules/bah.crypto feature request
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| Hey Brucey, A MD5File() function would be nice, to calculate the hash of a file. Loading a bigfile with LoadText() isn't always going to work. The Perl module Digest::MD5 (and Digest::MD5::File) are able to do this. The maintainer of that module is using a method called add() which adds to the MD5 hash, so you can open a stream to a file, load it bit by bit and pass the contents to the MD5 object without loading the full file into memory. Direct link to the C code Digest::MD5 Digest::MD5::File It would be really nice if you could add this :-). Thanks. Update: Browsing through the source wouldn't you be able to do this with MD5_Update() from openssl? |
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| Well, all the code is already there for you to make that up yourself :-p (see the digest example for use of "update" method) You have the choice of using the "easy" API, or the meaty low-level API. However, I've just updated all the digest functions to now take either a String (which they did previously) or a TStream. There's a small "stream_digest.bmx" example too, so that you can see it in action. Check out latest SVN for the updates. :o) |
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| I know all the code is there and I'd probably would've been able to do it myself. But, as a programmer I'm lazy :-). So I thank you for doing the hard work ^_^. So far seems to be working perfectly. Thanks. |
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| One *bug* report :-) Shouldn't you reset the position of the stream after being done to 0 or the last known position? I currently have to do it manually, no biggie, but it would just be a little bit nicer if it did it by itself. Anyway, I made a patch. I'm not sure about the stream.Seek(0) if the ctx.DigestUpdate() returns False, but seems logical to me. Index: crypto.bmx =================================================================== --- crypto.bmx (revision 829) +++ crypto.bmx (working copy) @@ -893,10 +893,13 @@ End If If Not ctx.DigestUpdate(data, count) Then + stream.Seek(0) Return Null End If Wend + + stream.Seek(0) Else Return Null |
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| Shouldn't you reset the position of the stream after being done to 0 or the last known position? Well, I can't assume that a stream you are giving me supports Seek(0). For example, an http stream wouldn't, so I think the interface really needs to be quite generic in that regards. No ? |
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| I hadn't thought of that :-). Good thinking. I'll revert my changes now. |
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