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Posted to users@httpd.apache.org by François Beaune <di...@gmail.com> on 2009/12/16 08:47:37 UTC
Re: [users@httpd] Using SSLCipherSuite to restrict to faster cipher
algorithms
Hey Justin,
Thanks for your answer. I did add the various versions of
the SSLCipherSuite directive to my virtual host container, sorry if that
wasn't clear.
In the meantime I found that, by inspecting the handshake between
TortoiseSVN and Apache, the connection does use RC4, which is good. Still,
I don't understand why this doesn't happen with Firefox (it always uses AES
256, which shouldn't be allowed, if I understand things correctly). Any
clue?
Cheers,
Franz
On Tue, Dec 15, 2009 at 8:26 PM, Justin Pasher
<ju...@newmediagateway.com>wrote:
> François Beaune wrote:
>
>> Hello,
>>
>> I have a setup where Apache 2.2.3 is serving a large SVN repository with
>> WebDAV over HTTPS (using basic authentication).
>>
>> Everything is working correctly; I would simply like to force usage of
>> faster cipher algorithms (trading some security in favor of speed) than what
>> seems to be allowed right now (for instance, AES 256 is used when I connect
>> with Firefox).
>>
>
> [snip]
>
>
> As an experiment, I have tried that (at the virtual host level):
>>
>> SSLProtocol all -SSLv2
>> SSLHonorCipherOrder on
>> SSLCipherSuite ALL:!ADH:+RC4+RSA:!HIGH:!LOW:!EXP:!NULL
>>
>
> I noticed that your VirtualHost container doesn't actually contain the
> SSLCipherSuite directive. Are you defining that somewhere else, such as in
> the global config scope? Double check to make sure that it's being defined
> globally as opposed to being wrapped inside another container object.
>
> Also, you can use this script to check which ciphers are supported by your
> site.
>
> http://www.lazorsoftware.com/lazorsoft/files/openssl_check.sh
>
> --
> Justin Pasher
>
> ---------------------------------------------------------------------
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> See <URL:http://httpd.apache.org/userslist.html> for more info.
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>
Re: [users@httpd] Using SSLCipherSuite to restrict to faster cipher
algorithms
Posted by François Beaune <di...@gmail.com>.
On Thu, Dec 17, 2009 at 6:21 PM, Justin Pasher
<ju...@newmediagateway.com>wrote:
> François Beaune wrote:
[snip]
> I'm still getting the same list, even if I use the SSLCipherSuite you
>> suggested, so it's clearly not used.
>>
>> On my side (in my subdomain's configuration), I only have one
>> SSLCipherSuite occurrence, inside the <VirtualHost> container I shown
>> earlier in this thread (and it's not in a <Location> or <Directory>
>> container).
>>
>> That being said, in /etc/httpd/conf.d/ssl.conf, there is another
>> occurrence:
>>
>> <VirtualHost _default_:443>
>> ...
>> SSLEngine on
>> SSLProtocol all -SSLv2
>> SSLCipherSuite ALL:!ADH:!EXPORT:!SSLv2:RC4+RSA:+HIGH:+MEDIUM:+LOW
>> ...
>> </VirtualHost>
>>
>> Shouldn't my configuration file have precedence over that?
>>
>
> So now we know how Firefox is still using AES256. It's just a matter of
> figuring out why the SSLCipherSuite is not being used. The first thing I'd
> try is replacing the SSLCipherSuite directory you found above (inside the
> <VirtualHost _default_:443> container). If that fixes the problem, then you
> at least know where it's picking up the setting. As far as WHY it's hitting
> that VirtualHost container, Apache should be falling back to that one if
> there is no other matching <VirtualHost> container for the request. Looking
> back at the original post, I see this...
>
>
> <VirtualHost XXX.XXX.XXX.XXX:443>
> ServerName svn.mydomain.net:443
> ...
> </VirtualHost>
>
> So I assume that the request is actually being made to the (masked) IP
> address XXX.XXX.XXX.XXX? One thought out from left field would be that the
> box has multiple IP addresses assigned and the request is actually hitting
> YYY.YYY.YYY.YYY instead of XXX.XXX.XXX.XXX, which would make it fall back to
> the default VirtualHost:443, I believe. Also, if you are trying to access
> the server via localhost, that would be coming from a different IP address
> (127.0.0.1), so it would also fall back to the default. Additional note: you
> don't need the ":443" on the ServerName.
>
> Now, if changing the SSLCipherSuite in the default VirtualHost does NOT
> register the change, then it would sound like it's not hitting ANY of the
> VirtualHost containers that have SSLCipherSuite defined. If that really is
> the case, you could always put the SSLCipherSuite in the global scope as a
> last resort, but ideally you could figure out why it's not recognizing the
> setting.
>
Getting back to this problem only now.
I tried changing the SSLCipherSuite directive in /etc/httpd/conf.d/ssl.conf
(in the <VirtualHost _default_:443> container), but that had no effect.
However, I also tried adding a global SSLCipherSuite directive outside any
container, and that had the intended effect:
$ ./openssl_check.sh svn.mydomain.net
Checking svn.mydomain.net:443 ...
- DHE-DSS-RC4-SHA
- EXP1024-DHE-DSS-RC4-SHA
- EXP1024-RC4-SHA
- EXP1024-DHE-DSS-DES-CBC-SHA
- EXP1024-DES-CBC-SHA
- ADH-AES256-SHA
- DHE-RSA-AES256-SHA
- DHE-DSS-AES256-SHA
+ AES256-SHA at Server public key is 2048 bit
- ADH-AES128-SHA
- DHE-RSA-AES128-SHA
- DHE-DSS-AES128-SHA
+ AES128-SHA at Server public key is 2048 bit
- EXP-KRB5-RC4-MD5
- EXP-KRB5-RC2-CBC-MD5
- EXP-KRB5-DES-CBC-MD5
- EXP-KRB5-RC4-SHA
- EXP-KRB5-RC2-CBC-SHA
- EXP-KRB5-DES-CBC-SHA
- KRB5-RC4-MD5
- KRB5-DES-CBC3-MD5
- KRB5-DES-CBC-MD5
- KRB5-RC4-SHA
- KRB5-DES-CBC3-SHA
- KRB5-DES-CBC-SHA
- ADH-DES-CBC3-SHA
- ADH-DES-CBC-SHA
- EXP-ADH-DES-CBC-SHA
- ADH-RC4-MD5
- EXP-ADH-RC4-MD5
- EDH-RSA-DES-CBC3-SHA
- EDH-RSA-DES-CBC-SHA
- EXP-EDH-RSA-DES-CBC-SHA
- EDH-DSS-DES-CBC3-SHA
- EDH-DSS-DES-CBC-SHA
- EXP-EDH-DSS-DES-CBC-SHA
+ DES-CBC3-SHA at Server public key is 2048 bit
- DES-CBC-SHA
- EXP-DES-CBC-SHA
- EXP-RC2-CBC-MD5
+ RC4-SHA at Server public key is 2048 bit
+ RC4-MD5 at Server public key is 2048 bit
- EXP-RC4-MD5
- DES-CBC3-MD5
- DES-CBC-MD5
- EXP-RC2-CBC-MD5
- RC2-CBC-MD5
- EXP-RC4-MD5
+ RC4-MD5 at Server public key is 2048 bit
- NULL-SHA
- NULL-MD5
It's basically the list you mentioned (except for the size of the public
keys).
So, it looks like none of the SSLCipherSuite directives inside virtual host
containers have any effect, only the global one has.
What I don't understand is that the other directives do have an effect. For
instance, the <Location /> block defined in the <VirtualHost
XXX.XXX.XXX.XXX:443> container is definitely taken into account, as my SVN
repository is properly served by Apache (everything is working perfectly).
Similarly, at some point I added LimitRequestBody and LimitXMLRequestBody
directives to this virtual host container, and they had the intended effect.
Why would it be different for SSLCipherSuite?
Thanks for your help.
Cheers,
Franz
Re: [users@httpd] Using SSLCipherSuite to restrict to faster cipher
algorithms
Posted by Justin Pasher <ju...@newmediagateway.com>.
François Beaune wrote:
> On Wed, Dec 16, 2009 at 7:00 PM, Justin Pasher
> <justinp@newmediagateway.com <ma...@newmediagateway.com>> wrote:
>
> [snip]
>
> Here is the SSLCipherSuite directive that I use on my servers to
> lock out insecure ciphers:
>
> SSLCipherSuite AES256-SHA:DES-CBC3-SHA:AES128-SHA:RC4-SHA:RC4-MD5
>
>
> I'm still getting the same list, even if I use the SSLCipherSuite you
> suggested, so it's clearly not used.
>
> On my side (in my subdomain's configuration), I only have one
> SSLCipherSuite occurrence, inside the <VirtualHost> container I shown
> earlier in this thread (and it's not in a <Location> or <Directory>
> container).
>
> That being said, in /etc/httpd/conf.d/ssl.conf, there is another
> occurrence:
>
> <VirtualHost _default_:443>
> ...
> SSLEngine on
> SSLProtocol all -SSLv2
> SSLCipherSuite ALL:!ADH:!EXPORT:!SSLv2:RC4+RSA:+HIGH:+MEDIUM:+LOW
> ...
> </VirtualHost>
>
> Shouldn't my configuration file have precedence over that?
So now we know how Firefox is still using AES256. It's just a matter of
figuring out why the SSLCipherSuite is not being used. The first thing
I'd try is replacing the SSLCipherSuite directory you found above
(inside the <VirtualHost _default_:443> container). If that fixes the
problem, then you at least know where it's picking up the setting. As
far as WHY it's hitting that VirtualHost container, Apache should be
falling back to that one if there is no other matching <VirtualHost>
container for the request. Looking back at the original post, I see this...
<VirtualHost XXX.XXX.XXX.XXX:443>
ServerName svn.mydomain.net:443
...
</VirtualHost>
So I assume that the request is actually being made to the (masked) IP
address XXX.XXX.XXX.XXX? One thought out from left field would be that
the box has multiple IP addresses assigned and the request is actually
hitting YYY.YYY.YYY.YYY instead of XXX.XXX.XXX.XXX, which would make it
fall back to the default VirtualHost:443, I believe. Also, if you are
trying to access the server via localhost, that would be coming from a
different IP address (127.0.0.1), so it would also fall back to the
default. Additional note: you don't need the ":443" on the ServerName.
Now, if changing the SSLCipherSuite in the default VirtualHost does NOT
register the change, then it would sound like it's not hitting ANY of
the VirtualHost containers that have SSLCipherSuite defined. If that
really is the case, you could always put the SSLCipherSuite in the
global scope as a last resort, but ideally you could figure out why it's
not recognizing the setting.
--
Justin Pasher
---------------------------------------------------------------------
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See <URL:http://httpd.apache.org/userslist.html> for more info.
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Re: [users@httpd] Using SSLCipherSuite to restrict to faster cipher
algorithms
Posted by François Beaune <di...@gmail.com>.
On Wed, Dec 16, 2009 at 7:00 PM, Justin Pasher
<ju...@newmediagateway.com>wrote:
[snip]
Here is the SSLCipherSuite directive that I use on my servers to lock out
> insecure ciphers:
>
> SSLCipherSuite AES256-SHA:DES-CBC3-SHA:AES128-SHA:RC4-SHA:RC4-MD5
>
> Try setting your config to this value. Obviously this is different than
> what you are trying to accomplish, but right now the goal is to figure out
> whether the SSLCipherSuite directive is actually being acknowledged. When
> you run the openssl_check.sh script again, it should return the following
> results:
>
> + AES256-SHA at Server public key is 1024 bit
> + AES128-SHA at Server public key is 1024 bit
> + DES-CBC3-SHA at Server public key is 1024 bit
> + RC4-SHA at Server public key is 1024 bit
> + RC4-MD5 at Server public key is 1024 bit
> + RC4-MD5 at Server public key is 1024 bit
>
> If you see anything different, then the SSLCipherSuite is not being set
> properly. Double check that you don't have multiple SSLCipherSuite
> directives set across different files. Also make sure you are not
> accidentally setting it within an unintentional container, such as
> <Directory> or <VirtualHost>. I know that on CentOS, the default config file
> that has the SSL directives actually contains the SSLCipherSuite directive
> within a <VirtualHost> container. That threw me off recently when I was
> trying to setup apache on a CentOS box for the first time.
I'm still getting the same list, even if I use the SSLCipherSuite you
suggested, so it's clearly not used.
On my side (in my subdomain's configuration), I only have one
SSLCipherSuite occurrence, inside the <VirtualHost> container I shown
earlier in this thread (and it's not in a <Location> or <Directory>
container).
That being said, in /etc/httpd/conf.d/ssl.conf, there is another occurrence:
<VirtualHost _default_:443>
...
SSLEngine on
SSLProtocol all -SSLv2
SSLCipherSuite ALL:!ADH:!EXPORT:!SSLv2:RC4+RSA:+HIGH:+MEDIUM:+LOW
...
</VirtualHost>
Shouldn't my configuration file have precedence over that?
Cheers,
Franz
Re: [users@httpd] Using SSLCipherSuite to restrict to faster cipher
algorithms
Posted by Justin Pasher <ju...@newmediagateway.com>.
François Beaune wrote:
> Sorry, I had overlooked your suggestion. Here's the output of the script:
>
> $ ./openssl_check.sh svn.mydomain.net <http://svn.mydomain.net>
> Checking svn.mydomain.net:443 <http://svn.mydomain.net:443> ...
> + EXP1024-RC4-SHA at Server public key is 2048 bit
> + EXP1024-DES-CBC-SHA at Server public key is 2048 bit
> + DHE-RSA-AES256-SHA at Server public key is 2048 bit
> + AES256-SHA at Server public key is 2048 bit
> + DHE-RSA-AES128-SHA at Server public key is 2048 bit
> + AES128-SHA at Server public key is 2048 bit
> + EDH-RSA-DES-CBC3-SHA at Server public key is 2048 bit
> + EDH-RSA-DES-CBC-SHA at Server public key is 2048 bit
> + EXP-EDH-RSA-DES-CBC-SHA at Server public key is 2048 bit
> + DES-CBC3-SHA at Server public key is 2048 bit
> + DES-CBC-SHA at Server public key is 2048 bit
> + EXP-DES-CBC-SHA at Server public key is 2048 bit
> + EXP-RC2-CBC-MD5 at Server public key is 2048 bit
> + RC4-SHA at Server public key is 2048 bit
> + RC4-MD5 at Server public key is 2048 bit
> + EXP-RC4-MD5 at Server public key is 2048 bit
> + EXP-RC2-CBC-MD5 at Server public key is 2048 bit
> + EXP-RC4-MD5 at Server public key is 2048 bit
> + RC4-MD5 at Server public key is 2048 bit
>
> I suspect this isn't correct though, as the list stays the same
> regardless of how I set SSLCipherSuite (I did restart Apache after
> each change to SSLCipherSuite). Either I'm not using the script
> correctly, or I'm not setting SSLCipherSuite correctly, or I'm doing
> another error. Any idea?
Everything with a plus sign is a cipher that is accepted by your apache
server, so given these results, the SSLCipherSuite directive is not
being registered.
Here is the SSLCipherSuite directive that I use on my servers to lock
out insecure ciphers:
SSLCipherSuite AES256-SHA:DES-CBC3-SHA:AES128-SHA:RC4-SHA:RC4-MD5
Try setting your config to this value. Obviously this is different than
what you are trying to accomplish, but right now the goal is to figure
out whether the SSLCipherSuite directive is actually being acknowledged.
When you run the openssl_check.sh script again, it should return the
following results:
+ AES256-SHA at Server public key is 1024 bit
+ AES128-SHA at Server public key is 1024 bit
+ DES-CBC3-SHA at Server public key is 1024 bit
+ RC4-SHA at Server public key is 1024 bit
+ RC4-MD5 at Server public key is 1024 bit
+ RC4-MD5 at Server public key is 1024 bit
If you see anything different, then the SSLCipherSuite is not being set
properly. Double check that you don't have multiple SSLCipherSuite
directives set across different files. Also make sure you are not
accidentally setting it within an unintentional container, such as
<Directory> or <VirtualHost>. I know that on CentOS, the default config
file that has the SSL directives actually contains the SSLCipherSuite
directive within a <VirtualHost> container. That threw me off recently
when I was trying to setup apache on a CentOS box for the first time.
--
Justin Pasher
---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
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Re: [users@httpd] Using SSLCipherSuite to restrict to faster cipher
algorithms
Posted by François Beaune <di...@gmail.com>.
On Wed, Dec 16, 2009 at 5:03 PM, Justin Pasher
<ju...@newmediagateway.com>wrote:
> François Beaune wrote:
>
>> Hey Justin,
>>
>> Thanks for your answer. I did add the various versions of the
>> SSLCipherSuite directive to my virtual host container, sorry if that wasn't
>> clear.
>>
>> In the meantime I found that, by inspecting the handshake between
>> TortoiseSVN and Apache, the connection does use RC4, which is good. Still,
>> I don't understand why this doesn't happen with Firefox (it always uses AES
>> 256, which shouldn't be allowed, if I understand things correctly). Any
>> clue?
>>
>
> Did you try running the shell script to verify that the server is correctly
> applying the SSLCipherSuite directive and only offering the ciphers you have
> allowed?
>
>
> http://www.lazorsoftware.com/lazorsoft/files/openssl_check.sh
>
>
Sorry, I had overlooked your suggestion. Here's the output of the script:
$ ./openssl_check.sh svn.mydomain.net
Checking svn.mydomain.net:443 ...
- DHE-DSS-RC4-SHA
- EXP1024-DHE-DSS-RC4-SHA
+ EXP1024-RC4-SHA at Server public key is 2048 bit
- EXP1024-DHE-DSS-DES-CBC-SHA
+ EXP1024-DES-CBC-SHA at Server public key is 2048 bit
- ADH-AES256-SHA
+ DHE-RSA-AES256-SHA at Server public key is 2048 bit
- DHE-DSS-AES256-SHA
+ AES256-SHA at Server public key is 2048 bit
- ADH-AES128-SHA
+ DHE-RSA-AES128-SHA at Server public key is 2048 bit
- DHE-DSS-AES128-SHA
+ AES128-SHA at Server public key is 2048 bit
- EXP-KRB5-RC4-MD5
- EXP-KRB5-RC2-CBC-MD5
- EXP-KRB5-DES-CBC-MD5
- EXP-KRB5-RC4-SHA
- EXP-KRB5-RC2-CBC-SHA
- EXP-KRB5-DES-CBC-SHA
- KRB5-RC4-MD5
- KRB5-DES-CBC3-MD5
- KRB5-DES-CBC-MD5
- KRB5-RC4-SHA
- KRB5-DES-CBC3-SHA
- KRB5-DES-CBC-SHA
- ADH-DES-CBC3-SHA
- ADH-DES-CBC-SHA
- EXP-ADH-DES-CBC-SHA
- ADH-RC4-MD5
- EXP-ADH-RC4-MD5
+ EDH-RSA-DES-CBC3-SHA at Server public key is 2048 bit
+ EDH-RSA-DES-CBC-SHA at Server public key is 2048 bit
+ EXP-EDH-RSA-DES-CBC-SHA at Server public key is 2048 bit
- EDH-DSS-DES-CBC3-SHA
- EDH-DSS-DES-CBC-SHA
- EXP-EDH-DSS-DES-CBC-SHA
+ DES-CBC3-SHA at Server public key is 2048 bit
+ DES-CBC-SHA at Server public key is 2048 bit
+ EXP-DES-CBC-SHA at Server public key is 2048 bit
+ EXP-RC2-CBC-MD5 at Server public key is 2048 bit
+ RC4-SHA at Server public key is 2048 bit
+ RC4-MD5 at Server public key is 2048 bit
+ EXP-RC4-MD5 at Server public key is 2048 bit
- DES-CBC3-MD5
- DES-CBC-MD5
+ EXP-RC2-CBC-MD5 at Server public key is 2048 bit
- RC2-CBC-MD5
+ EXP-RC4-MD5 at Server public key is 2048 bit
+ RC4-MD5 at Server public key is 2048 bit
- NULL-SHA
- NULL-MD5
I suspect this isn't correct though, as the list stays the same regardless
of how I set SSLCipherSuite (I did restart Apache after each change to
SSLCipherSuite). Either I'm not using the script correctly, or I'm not
setting SSLCipherSuite correctly, or I'm doing another error. Any idea?
Thanks for your help.
Cheers,
Franz
Re: [users@httpd] Using SSLCipherSuite to restrict to faster cipher
algorithms
Posted by Justin Pasher <ju...@newmediagateway.com>.
François Beaune wrote:
> Hey Justin,
>
> Thanks for your answer. I did add the various versions of
> the SSLCipherSuite directive to my virtual host container, sorry if
> that wasn't clear.
>
> In the meantime I found that, by inspecting the handshake between
> TortoiseSVN and Apache, the connection does use RC4, which is good.
> Still, I don't understand why this doesn't happen with Firefox (it
> always uses AES 256, which shouldn't be allowed, if I
> understand things correctly). Any clue?
Did you try running the shell script to verify that the server is
correctly applying the SSLCipherSuite directive and only offering the
ciphers you have allowed?
http://www.lazorsoftware.com/lazorsoft/files/openssl_check.sh
--
Justin Pasher
---------------------------------------------------------------------
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See <URL:http://httpd.apache.org/userslist.html> for more info.
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" from the digest: users-digest-unsubscribe@httpd.apache.org
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