At 01:38 AM 11/3/98 -0300, sqrmax@cvtci.com.ar wrote:
What do you think about using one of the unused bits in the image header as a flag to tell if the image was properly closed or not? This would allow the VM to warn the user if he/she tries to open a not closed image. An example of this is to open an image twice, which can result in a damaged changes
file.
If the goal is to prevent changes corruption, wouldn't it be better to open the changes file with exclusive sharing access? Mabey on the first time you write something to changes.
I could easily imagine cases where you might want multiple instances of an image open, each in a different process, that never write to a changes file. For example, an end application image (people might actually want to deploy finished Smalltalk apps, not just live in the development environment).
Or mabey some method of putting a checksum on an image. The very best case would be you put a digital signature on an image, not only would this prove the image was not corrupted, but could prove where it came from. The danger of viruses loading in an image seem quite real. Every time you fileIn a piece of random Smalltalk code, your image is in danger of getting infected. The Java folks have taken steps to prevent this, even the Microsoft folks have taken steps. Any kind of crypto support in Squeak might cause US export issues though :(
Mabey instead of making armchair comments, I should look into what really might be done to improve Squeak security. Any pointers to previous Smalltalk security projects?
- Jan ___________________________________________________________________ Paradigm Matrix Inc., San Ramon California "video products and development services for Win32 platforms" Internet: Jan Bottorff janb@pmatrix.com WWW http://www.pmatrix.com Phone: voice (925) 803-9318 fax (925) 803-9397 PGP: public key http://www-swiss.ai.mit.edu/~bal/pks-toplev.html fingerprint 52 CB FF 60 91 25 F9 44 6F 87 23 C9 AB 5D 05 F6 ___________________________________________________________________
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