Author pitrou
Recipients jcea, naif, pitrou
Date 2011-12-19.10:44:53
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Message-id <1324291455.3588.7.camel@localhost.localdomain>
In-reply-to <1324290754.24.0.917273225252.issue13627@psf.upfronthosting.co.za>
Content
> So, with this patch it should be possible to strictly enable ciphers such as:
> ECDHE-RSA-AES256-SHA   SSLv3 Kx=ECDH     Au=RSA  Enc=AES(256) Mac=SHA1
> ECDHE-ECDSA-AES256-SHA SSLv3 Kx=ECDH     Au=ECDSA Enc=AES(256) Mac=SHA1
> ECDH-RSA-AES256-SHA    SSLv3 Kx=ECDH/RSA Au=ECDH Enc=AES(256) Mac=SHA1
> ECDH-ECDSA-AES256-SHA  SSLv3 Kx=ECDH/ECDSA Au=ECDH Enc=AES(256) Mac=SHA1
> 
> Which ciphers did you negotiated succesfully?

I didn't try to negotiate a specific cipher, I just saw that the
selected cipher was ECDHE-RSA-AES256-SHA (using a standard self-signed
certificate). I suppose other ciphers are accessible as well.

> While with the implementation of http://bugs.python.org/issue13627
> (DH/DHE ciphers) we should be able to negotiate:

You mean issue13626.

> Do you expect it would be a difficult step to handle also the DH/DHE
> (non ECC) negotiation?

No, but that's issue13626 :)

> Additionally it would be imho very important if the Python language
> would provide a "default ciphers setup" that look at maximum
> compatibility, performance and security.

You have the set_ciphers() method which allows you to set a "cipher
string":
http://docs.python.org/dev/library/ssl.html#ssl.SSLContext.set_ciphers
OpenSSL itself has several generic cipher settings available:
http://www.openssl.org/docs/apps/ciphers.html#CIPHER_LIST_FORMAT

For example the following setting gives you only ECDH ciphers with
strong encryption and authentication:

$ openssl ciphers -v 'kEECDH:!NULL:!aNULL'
ECDHE-RSA-AES256-SHA    SSLv3 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA1
ECDHE-ECDSA-AES256-SHA  SSLv3 Kx=ECDH     Au=ECDSA Enc=AES(256)  Mac=SHA1
ECDHE-RSA-DES-CBC3-SHA  SSLv3 Kx=ECDH     Au=RSA  Enc=3DES(168) Mac=SHA1
ECDHE-ECDSA-DES-CBC3-SHA SSLv3 Kx=ECDH     Au=ECDSA Enc=3DES(168) Mac=SHA1
ECDHE-RSA-AES128-SHA    SSLv3 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA1
ECDHE-ECDSA-AES128-SHA  SSLv3 Kx=ECDH     Au=ECDSA Enc=AES(128)  Mac=SHA1
ECDHE-RSA-RC4-SHA       SSLv3 Kx=ECDH     Au=RSA  Enc=RC4(128)  Mac=SHA1
ECDHE-ECDSA-RC4-SHA     SSLv3 Kx=ECDH     Au=ECDSA Enc=RC4(128)  Mac=SHA1

We are not cryptography experts and I don't think it would be a good
idea to maintain our own list of ciphers.

(furthermore, I don't think "maximum compatibility, performance and
security" are generally compatible with each other)
History
Date User Action Args
2011-12-19 10:44:54pitrousetrecipients: + pitrou, jcea, naif
2011-12-19 10:44:54pitroulinkissue13627 messages
2011-12-19 10:44:54pitroucreate