Nmap Development mailing list archives
Re: [NSE] Script ssl-enum-ciphers should not penalize 3DES
From: Daniel Miller <bonsaiviking () gmail com>
Date: Wed, 24 Aug 2016 08:41:51 -0500
nnposter, There's no way we could have known this 2 weeks ago, but it sounds like 3DES in TLS has some problems. The "SWEET32" attack [1] has demonstrated block collisions in 64-bit blocksize ciphers after 2^32 blocks (about 32GB), and decryption of small values (such as cookies) after 750GB or so. OpenSSL is downgrading 3DES to MEDIUM and declares "triple-DES should now be considered as “bad” as RC4." [2] I think we should at least back out the change that artificially boosted 3DES's cipher strength. Depending on how discussion plays out with the crypto experts over the next few weeks, we may consider adding a warning like we do for SHA-1 certs, RC4, and other things. Dan [1] https://sweet32.info/ [2] https://www.openssl.org/blog/blog/2016/08/24/sweet32/ On Sat, Aug 6, 2016 at 5:14 PM, nnposter <nnposter () users sourceforge net> wrote:
Rob's note below is the only feedback I have received so far. As such I am going to commit the proposed change later next week unless anybody objects. Cheers, nnposter On 7/29/16 11:38 AM, Rob Nicholls wrote:I'm fairly happy with that suggestion. I believe Nessus also treats112-bit(i.e. 3DES) keys as a "High" strength cipher. Rob -----Original Message----- From: dev [mailto:dev-bounces () nmap org] On Behalf Of nnposter Sent: 29 July 2016 18:10 To: dev () nmap org Subject: [NSE] Script ssl-enum-ciphers should not penalize 3DES As of now, script ssl-enum-ciphers is rating cipher suites based on 3DES (112-bit keys) the same as those using plain 56-bit DES. Given that 56-bit keys are considered easily within the reach of average adversaries while 3DES keys are deemed safe at the moment, I would liketopropose that we change the rating to treat 3DES on par with 128-bitciphers.This position is supported by SSL Labs, which does not flag presence of3DEScipher suites, while rating "Cipher Strength" of such sites as "Green". More details at https://github.com/nmap/nmap/issues/474 Please voice any concerns with such a change. Cheers, nnposter_______________________________________________ Sent through the dev mailing list https://nmap.org/mailman/listinfo/dev Archived at http://seclists.org/nmap-dev/
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Current thread:
- [NSE] Script ssl-enum-ciphers should not penalize 3DES nnposter (Jul 29)
- RE: [NSE] Script ssl-enum-ciphers should not penalize 3DES Rob Nicholls (Jul 29)
- Re: [NSE] Script ssl-enum-ciphers should not penalize 3DES nnposter (Aug 06)
- Re: [NSE] Script ssl-enum-ciphers should not penalize 3DES Daniel Miller (Aug 24)
- Re: [NSE] Script ssl-enum-ciphers should not penalize 3DES nnposter (Aug 24)
- Re: [NSE] Script ssl-enum-ciphers should not penalize 3DES nnposter (Aug 06)
- RE: [NSE] Script ssl-enum-ciphers should not penalize 3DES Rob Nicholls (Jul 29)