[arch-general] haveged and Secure Cryptography
Does anyone know if haveged significantly affects things like truecrypt, cryptsetup, RSA, or SSL if you happen to leave the daemon running for long periods of time? I'm sure that it's always going to be "random enough", but I often make use of Archlinux in forensic environments involving encrypted disks and files or transferring things over SSL, so I do need to know if there is even a theoretical weakness in my environment in case my tools and methodologies are called into question. Thanks -- David Hunter
[2012-07-19 22:10:05 -0700] David Hunter:
I'm sure that it's always going to be "random enough", but I often make use of Archlinux in forensic environments involving encrypted disks and files or transferring things over SSL, so I do need to know if there is even a theoretical weakness in my environment in case my tools and methodologies are called into question.
There are no known weaknesses as far as I know, but you can always question the hypothesis that runtime measurements bear a significant amount of entropy. Now if you are that paranoid you might also want to avoid kernel-gathered entropy and just get yourself a physical entropy generating device. -- Gaetan
Does anyone know if haveged significantly affects things like truecrypt, cryptsetup, RSA, or SSL if you happen to leave the daemon running for long periods of time? I'm sure that it's always going to be "random enough", but I often make use of Archlinux in forensic environments involving encrypted disks and files or transferring things over SSL, so I do need to know if there is even a theoretical weakness in my environment in case my tools and methodologies are called into question.
If your task uses /dev/random then it blocks on low entropy conditions. I believe that is the only time haveged fills the pool. So the question becomes If my device needs lots of entropy is haveged as strong or stronger than the Linux RNG and does or can haveged be made to collect randomness when idle. This fired across the android list recently and gives with it's references an idea of weaknesses in the Linux RNG. Were these weaknesses happening at times of pool exhaustion or generally, I wonder? https://factorable.net/paper.html OpenBSD a year or two ago actually made all their random devices link to the one because it incorporates haveged like functionality and more and with it's RC4 cipher multiplies it to hundreds of megabytes of good random data per second. -- ________________________________________________________ Why not do something good every day and install BOINC. ________________________________________________________
participants (3)
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David Hunter
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Gaetan Bisson
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Kevin Chadwick