Are DHE_DSS cipher suites not supported?

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Are DHE_DSS cipher suites not supported?

John Jiang
Hi,
I'm using OpenSSL 1.1.1d.
Just want to confirm if DHE_DSS cipher suites are not supported by this version.

Please consider the below simple case,
1. s_server uses a DSA certifcate
2. force s_client to use TLS 1.2 and TLS_DHE_DSS_WITH_AES_256_GCM_SHA384 (DHE-DSS-AES256-GCM-SHA384)
the connection failed, and s_server reported: no shared cipher:ssl/statem/statem_srvr.c:2259

But I still can see this cipher suite in the below doc,
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Re: Are DHE_DSS cipher suites not supported?

Viktor Dukhovni
On Fri, Oct 25, 2019 at 03:33:43PM +0800, John Jiang wrote:

> I'm using OpenSSL 1.1.1d.
> Just want to confirm if DHE_DSS cipher suites are not supported by this
> version.

They are supported, but:

    * DSS ciphersuites are disabled by DEFAULT.  You need to
      specify an explicit "-cipher" option to enable these,
      for example:

        $ openssl s_server -accept 12345 \
            -tls1_2 -cipher DHE-DSS-AES256-GCM-SHA384 \
            -dhparam dhparam.pem -key dsakey.pem -cert dsacert.pem

      or more typically:

        -cipher 'ALL:!RC4:!aNULL'

    * You should also supply DH parameters as above:

        -dhparam dhparam.pem

      I generated these with:

        $ openssl genpkey -genparam -algorithm dh \
            -pkeyopt dh_paramgen_prime_len:2048 -out dhparam.pem

--
        Viktor.
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Re: Are DHE_DSS cipher suites not supported?

Matt Caswell-2


On 25/10/2019 09:39, Viktor Dukhovni wrote:

> On Fri, Oct 25, 2019 at 03:33:43PM +0800, John Jiang wrote:
>
>> I'm using OpenSSL 1.1.1d.
>> Just want to confirm if DHE_DSS cipher suites are not supported by this
>> version.
>
> They are supported, but:
>
>     * DSS ciphersuites are disabled by DEFAULT.  You need to
>       specify an explicit "-cipher" option to enable these,
>       for example:
>
>         $ openssl s_server -accept 12345 \
>    -tls1_2 -cipher DHE-DSS-AES256-GCM-SHA384 \
>    -dhparam dhparam.pem -key dsakey.pem -cert dsacert.pem
>
>       or more typically:
>
> -cipher 'ALL:!RC4:!aNULL'
>
>     * You should also supply DH parameters as above:

This step is optional. It will work just fine with default parameters if
you don't specify them.

Matt



>
> -dhparam dhparam.pem
>
>       I generated these with:
>
> $ openssl genpkey -genparam -algorithm dh \
>    -pkeyopt dh_paramgen_prime_len:2048 -out dhparam.pem
>
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Re: Are DHE_DSS cipher suites not supported?

John Jiang
On Fri, Oct 25, 2019 at 8:50 PM Matt Caswell <[hidden email]> wrote:


On 25/10/2019 09:39, Viktor Dukhovni wrote:
> On Fri, Oct 25, 2019 at 03:33:43PM +0800, John Jiang wrote:
>
>> I'm using OpenSSL 1.1.1d.
>> Just want to confirm if DHE_DSS cipher suites are not supported by this
>> version.
>
> They are supported, but:
>
>     * DSS ciphersuites are disabled by DEFAULT.  You need to
>       specify an explicit "-cipher" option to enable these,
>       for example:
>
>         $ openssl s_server -accept 12345 \
>           -tls1_2 -cipher DHE-DSS-AES256-GCM-SHA384 \
>           -dhparam dhparam.pem -key dsakey.pem -cert dsacert.pem
>
>       or more typically:
>
>       -cipher 'ALL:!RC4:!aNULL'
>
>     * You should also supply DH parameters as above:

This step is optional. It will work just fine with default parameters if
you don't specify them.
I only add option -cipher to s_server. That works for me.
Thanks!
 

Matt



>
>       -dhparam dhparam.pem
>
>       I generated these with:
>
>       $ openssl genpkey -genparam -algorithm dh \
>           -pkeyopt dh_paramgen_prime_len:2048 -out dhparam.pem
>