[PATCH] cipher: fix dhgex for non-GCM ciphers for OpenSSL 3.0

[Marc Kleine-Budde]

On 12/7/20 5:10 PM, Marc Kleine-Budde wrote:
> On 12/4/20 3:36 AM, Darren Tucker wrote:
>> Thanks for the investigation.
>>
>>> The issue is that openssh needs the "current" IV state (which the 
>>> now-deprecated EVP_CIPHER_CTX_iv() used to return), but it's calling the 
>>> wrong openssl function to obtain it.
>>
>> It's not that simple.
>>
>> In 2018, LibreSSL added EVP_CIPHER_CTX_get_iv (
>> https://github.com/libressl-portable/openbsd/commit/db321d7792) which
>> returns the current IV, and OpenSSH has been using it ever since.
>>
>> In 2020, OpenSSL added a function of the same name (
>> https://github.com/openssl/openssl/commit/79f4417ed94) which behaves
>> differently.  Maybe OpenSSL could change it before 3.0 instead of shipping
>> an incompatible API?  EVP_CIPHER_CTX_get_original_iv would be consistent
>> with the function they deprecated. ie
>>
>> EVP_CIPHER_CTX_get_iv -> EVP_CIPHER_CTX_get_original_iv
>> EVP_CIPHER_CTX_get_iv_state -> EVP_CIPHER_CTX_get_iv
> 
> I tried to wrap up the problem and created an openssl issue:
> 
> https://github.com/openssl/openssl/issues/13631

Which turned out to be a duplicate of

https://github.com/openssl/openssl/issues/13411

Are you interested in another take on a patch to fix OpenSSH with the current
OpenSSL-3.0?

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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