From c4fcaab5e19afea97780be5eb169ff53a8a9a21e Mon Sep 17 00:00:00 2001 From: Greg Hudson Date: Tue, 13 Oct 2009 19:43:17 +0000 Subject: [PATCH] Fix preauth looping in krb5_get_init_creds In 1.7, krb5_get_init_creds will continue attempting the same built-in preauth mechanism (e.g. encrypted timestamp) until the loop counter maxes out. Until the preauth framework can remember not to retry built-in mechanisms, only continue with preauth after a PREAUTH_FAILED error resulting from optimistic preauth. ticket: 6573 tags: pullup target_version: 1.7.1 git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@22890 dc483132-0cff-0310-8789-dd5450dbe970 --- src/lib/krb5/krb/get_in_tkt.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/src/lib/krb5/krb/get_in_tkt.c b/src/lib/krb5/krb/get_in_tkt.c index b4d729fbc..a381c5c7e 100644 --- a/src/lib/krb5/krb/get_in_tkt.c +++ b/src/lib/krb5/krb/get_in_tkt.c @@ -1055,6 +1055,21 @@ build_in_tkt_name(krb5_context context, return ret; } +/* Decide whether to continue trying AS-REQ preauthentication. */ +static krb5_boolean +should_continue_preauth(krb5_ui_4 error, int loopcount) +{ + /* + * Continue on PREAUTH_FAILED only on the first iteration, which + * would imply that we did optimistic preauth unsuccessfully. We + * could continue on later iterations if the preauth framework + * reliably remembered what mechanisms had been tried, but + * currently it does not do so for built-in mechanisms. + */ + return (error == KDC_ERR_PREAUTH_REQUIRED || + (error == KDC_ERR_PREAUTH_FAILED && loopcount == 0)); +} + krb5_error_code KRB5_CALLCONV krb5_get_init_creds(krb5_context context, krb5_creds *creds, @@ -1412,8 +1427,7 @@ krb5_get_init_creds(krb5_context context, &out_padata, &retry); if (ret !=0) goto cleanup; - if ((err_reply->error == KDC_ERR_PREAUTH_REQUIRED ||err_reply->error == KDC_ERR_PREAUTH_FAILED) -&& retry) { + if (should_continue_preauth(err_reply->error, loopcount) && retry) { /* reset the list of preauth types to try */ if (preauth_to_use) { krb5_free_pa_data(context, preauth_to_use); -- 2.26.2