On 06/10/2011 12:21 PM, Massimiliano Pala wrote:

Hi all,

are there examples on how to use STARTLS without requiring that the server's certificate is trusted ?

If the crypto api used in the ldap library is OpenSSL, that is easy:

• create a new ssl_ctx() with SSL_CTX_new()
• set my function as the verify function with SSL_CTX_set_verify()
• use the LDAP_OPT_X_TLS_CTX option to point to my new ssl_ctx

My problem is: when GnuTLS or NSS crypto libraries are used instead, how do I force the same behavior ? Or, if providing my own function is not possible, how do I force the STARTLS to go on also if it finds non-trusted server/CA certificates ?

man ldap.conf TLS_REQCERT <level> never, allow, try

Thanks, Max

On 06/10/2011 02:11 PM, Massimiliano Pala wrote:

Hi Rich,

that's not really what I wanted.. I am developing my own ldap client and I wanted to know what is the code path to set the option.

I tried to use the following:

ldap_set_option(ld, LDAP_OPT_X_TLS_REQUIRE_CERT, "never")

but it always fails ( != 0).

man ldap_set_option

LDAP_OPT_X_TLS_REQUIRE_CERT Sets/gets the peer certificate checking strategy, one of LDAP_OPT_X_TLS_NEVER, LDAP_OPT_X_TLS_HARD, LDAP_OPT_X_TLS_DEMAND, LDAP_OPT_X_TLS_ALLOW, LDAP_OPT_X_TLS_TRY.

int reqcert = LDAP_OPT_X_TLS_NEVER; ... rc = ldap_set_option(ld, LDAP_OPT_X_TLS_REQUIRE_CERT, &reqcert);

Also, I would like to know if there's a possibility to set a callback for the verify of the certificates.

No that I know of. The problem here is - what would be passed to this callback? A certificate? In which format?

Cheers, Max

On 06/10/2011 03:05 PM, Rich Megginson wrote: [...]

...

TLS_REQCERT <level> never, allow, try

On Fri, 10 Jun 2011, Massimiliano Pala wrote:

that's not really what I wanted.. I am developing my own ldap client and I wanted to know what is the code path to set the option.

I tried to use the following:

ldap_set_option(ld, LDAP_OPT_X_TLS_REQUIRE_CERT, "never")

but it always fails ( != 0).

Howard has already pointed out that the value must be an LDAP_OPT_X_TLS_* constant and not a string; I just wanted to add that in version 2.3 and earlier, that option (and most of the other TLS options) could only be set globally: ldap_set_option() would fail for them if the first argument wasn't NULL. So, make sure you're building against a current version.

Philip Guenther