> I don't like partial reads/writes and think that a lot of people get > them wrong, because they often only check for negative return values. The v1 patch, which did it right IMHO, didn't do partial reads in the case we're talking about: + if (count > 256) + return -EINVAL; > In case of urandom extraction, I wouldn't actually limit the number of > bytes. A lot of applications I have seen already extract more than 128 > out of urandom (not for seeding a prng but just to mess around with some > memory). I don't see a reason why getrandom shouldn't be used for that. > It just adds one more thing to look out for if using getrandom() in > urandom mode, especially during porting an application over to this new > interface. Again, I disagree. If it's "just messing around" code, use /dev/urandom. It's more portable and you don't care about the fd exhaustion attacks. If it's actual code to be used in anger, fix it to not abuse /dev/urandom. You're right that a quick hack might be "broken on purpose", but without exception, *all* code that I have seen which reads 64 or more bytes from /dev/*random is broken, and highlighting the brokenness is a highly desirable thing. The sole and exclusive reason for this syscall to exist at all is to solve a security problem. Supporting broken security code does no favors to anyone. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
