[Freeipa-users] How to turn off RC4 in 389ds???

Wed Sep 23 18:53:06 UTC 2015

On 09/23/2015 05:05 PM, Michael Lasevich wrote:
> Yes, I am talking about 389ds as is integrated in FreeIPA (would be silly to
> post completely non-IPA questions to this list...).

You would not be the first to do it :-)

> I am running FreeIPA 4.1.4 on CentOS 7.1 and RC4 is enabled on port 636 no
> matter what I do.
>
> I am running "CentOS Linux release 7.1.1503 (Core)"
>
> Relevant Packages:
>
> freeipa-server-4.1.4-1.el7.centos.x86_64
> 389-ds-base-1.3.3.8-1.el7.centos.x86_64
> nss-3.19.1-5.el7_1.x86_64
> openssl-1.0.1e-42.el7.9.x86_64
>
> LDAP setting (confirmed that in error.log there is no menition of RC4 in list
> of ciphers):
>
> nsSSL3Ciphers:
> -rc4,-rc4export,-rc2,-rc2export,-des,-desede3,-rsa_rc4_128_md5,-rsa_rc4_128_sha,+rsa_3des_sha,-rsa_des_sha,+rsa_fips_3des_sha,+fips_3des_sha,-rsa_fips_des_sha,-fips_des_sha,-rsa_rc4_40_md5,-rsa_rc2_40_md5,-rsa_null_md5,-rsa_null_sha,-tls_rsa_export1024_with_rc4_56_sha,-rsa_rc4_56_sha,-tls_rsa_export1024_with_des_cbc_sha,-rsa_des_56_sha,-fortezza,-fortezza_rc4_128_sha,-fortezza_null,-dhe_dss_des_sha,+dhe_dss_3des_sha,-dhe_rsa_des_sha,+dhe_rsa_3des_sha,+tls_rsa_aes_128_sha,+rsa_aes_128_sha,+tls_dhe_dss_aes_128_sha,+tls_dhe_rsa_aes_128_sha,+tls_rsa_aes_256_sha,+rsa_aes_256_sha,+tls_dhe_dss_aes_256_sha,+tls_dhe_rsa_aes_256_sha,-tls_dhe_dss_1024_rc4_sha,-tls_dhe_dss_rc4_128_sha

Something is really strange here. We need to see settings in 
"cn=encryption,cn=config" to investigate further.

$ ldapsearch -h ipa.example.com -b cn=encryption,cn=config -D "cn=Directory 
Manager" -x -W

should be a good start to give this information. nsSSL3Ciphers for example 
should be set to "+all" and "allowWeakCipher" to off, as per

http://fedorahosted.org/freeipa/ticket/4395

> Slapd "error" log showing no ciphersuites supporting RC4:
>
> [23/Sep/2015:08:51:04 -0600] SSL Initialization - Configured SSL version range:
> min: TLS1.0, max: TLS1.2
> [23/Sep/2015:08:51:04 -0600] - SSL alert: Cipher suite fortezza is not
> available in NSS 3.16.  Ignoring fortezza
> [23/Sep/2015:08:51:04 -0600] - SSL alert: Cipher suite fortezza_rc4_128_sha is
> not available in NSS 3.16.  Ignoring fortezza_rc4_128_sha
> [23/Sep/2015:08:51:04 -0600] - SSL alert: Cipher suite fortezza_null is not
> available in NSS 3.16.  Ignoring fortezza_null
> [23/Sep/2015:08:51:04 -0600] - SSL alert: Configured NSS Ciphers
> [23/Sep/2015:08:51:04 -0600] - SSL alert:
> TLS_DHE_RSA_WITH_AES_128_CBC_SHA: enabled
> [23/Sep/2015:08:51:04 -0600] - SSL alert:
> TLS_DHE_DSS_WITH_AES_128_CBC_SHA: enabled
> [23/Sep/2015:08:51:04 -0600] - SSL alert:
> TLS_DHE_RSA_WITH_AES_256_CBC_SHA: enabled
> [23/Sep/2015:08:51:04 -0600] - SSL alert:
> TLS_DHE_DSS_WITH_AES_256_CBC_SHA: enabled
> [23/Sep/2015:08:51:04 -0600] - SSL alert:       TLS_RSA_WITH_AES_128_CBC_SHA:
> enabled
> [23/Sep/2015:08:51:04 -0600] - SSL alert:       TLS_RSA_WITH_AES_256_CBC_SHA:
> enabled
> [23/Sep/2015:08:51:04 -0600] - 389-Directory/1.3.3.8 <http://1.3.3.8>
> B2015.040.128 starting up
>
>
> But sslscan returns:
>
> $ sslscan --no-failed localhost:636
> ...
>
> Supported Server Cipher(s):
>
>      Accepted  TLSv1  256 bits  AES256-SHA
>      Accepted  TLSv1  128 bits  AES128-SHA
>      Accepted  TLSv1  128 bits  DES-CBC3-SHA
>      Accepted  TLSv1  128 bits  RC4-SHA
>      Accepted  TLSv1  128 bits  RC4-MD5
>      Accepted  TLS11  256 bits  AES256-SHA
>      Accepted  TLS11  128 bits  AES128-SHA
>      Accepted  TLS11  128 bits  DES-CBC3-SHA
>      Accepted  TLS11  128 bits  RC4-SHA
>      Accepted  TLS11  128 bits  RC4-MD5
>      Accepted  TLS12  256 bits  AES256-SHA256
>      Accepted  TLS12  256 bits  AES256-SHA
>      Accepted  TLS12  128 bits  AES128-GCM-SHA256
>      Accepted  TLS12  128 bits  AES128-SHA256
>      Accepted  TLS12  128 bits  AES128-SHA
>      Accepted  TLS12  128 bits  DES-CBC3-SHA
>      Accepted  TLS12  128 bits  RC4-SHA
>      Accepted  TLS12  128 bits  RC4-MD5
>
> ...
>
>
> I would assume the sslscan is broken, but nmap and other scanners all confirm
> that RC4 is still on.
>
> -M
>
>
> On Wed, Sep 23, 2015 at 3:35 AM, Martin Kosek <mkosek at redhat.com
> <mailto:mkosek at redhat.com>> wrote:
>
>     On 09/23/2015 11:00 AM, Michael Lasevich wrote:
>      > OK, this is most bizarre issue,
>      >
>      > I am trying to disable RC4 based TLS Cipher Suites in LDAPs(port 636) and
>      > for the life of me cannot get it to work
>      >
>      > I have followed many nearly identical instructions to create ldif file and
>      > change "nsSSL3Ciphers" in "cn=encryption,cn=config". Seems simple enough -
>      > and I get it to take, and during the startup I can see the right SSL Cipher
>      > Suites listed in errors.log - but when it starts and I probe it, RC4
>      > ciphers are still there. I am completely confused.
>      >
>      > I tried setting "nsSSL3Ciphers" to "default" (which does not have "RC4")
>      > and to old style cyphers lists(lowercase), and new style cypher
>      > lists(uppercase), and nothing seems to make any difference.
>      >
>      > Any ideas?
>      >
>      > -M
>
>     Are you asking about standalone 389-DS or the one integrated in FreeIPA? As
>     with currently supported versions of FreeIPA, RC4 ciphers should be already
>     gone, AFAIK.
>
>     In RHEL/CentOS world, it should be fixed in 6.7/7.1 or later:
>
>     https://bugzilla.redhat.com/show_bug.cgi?id=1154687
>     https://fedorahosted.org/freeipa/ticket/4653
>
>