Segfault when setting bad olcTLSCipherSuite

[Joonas Koivunen]

Steps to reproduce:

1. Configure olcTLSCertificateFile & olcTLSCertificateKeyFile:
dn: cn=config
changeType: modify
add: olcTLSCertificateFile
olcTLSCertificateFile: /some/valid/pemfile/path
-
add: olcTLSCertificateKeyFile
olcTLSCertificateKeyFile: /some/valid/pemfile/path

(At this point openldap started to support STARTTLS and began working as a sssd authentication backend.)

2. Try configuring olcTLSCipherSuite to an openssl kind, for example:
dn: cn=config
changeType: modify
add: olcTLSCipherSuite
olcTLSCipherSuite: TLSv1+RSA:!NULL:!EXP

Expected result in gnutls compiled openldap: some kind of refusal of configuration change (gnutls does not apparently support any kind of ciphersuite names like openssl).

Actual result: segfault [01-slapd-stderr.log]

Syslog message about crash: kernel: [ 4158.532053] slapd[2696]: segfault at 7fa824106008 ip 00007fa837ad10b5 sp 00007fa830df8110 error 4 in libc-2.15.so[7fa837a52000+1b3000]

From administrators perspective openldap would be easier to configure should it be compiled against openssl instead of gnutls as ciphersuites would be simpler to specify. I'm not aware if openssl build would crash here as well. Crash is however rather bad indicator of "unsupported configuration value".

# apt-cache policy slapd
slapd:
  Installed: 2.4.28-1.1ubuntu4
  Candidate: 2.4.28-1.1ubuntu4
  Version table:
 *** 2.4.28-1.1ubuntu4 0
        500 http://fi.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status

# lsb_release -rd
Description: Ubuntu 12.04 LTS
Release: 12.04

# slapd -VVV
@(#) $OpenLDAP: slapd (Apr 5 2012 16:22:20) $
        buildd@allspice:/build/buildd/openldap-2.4.28/debian/build/servers/slapd

Included static backends:
    config
    ldif

[C de-Avillez (hggdh2)]

Marking Medium importance.