File _service:tar_scm_kernel_repo:backport-0002-CVE-... of Package samba

File _service:tar_scm_kernel_repo:backport-0002-CVE-2020-25719-sign-and-verify-PAC-with-ticket-principal.patch of Package samba

From 34347586375dea9b615fb6a0218bcb5927031e4d Mon Sep 17 00:00:00 2001
From: Isaac Boukris <iboukris@gmail.com>
Date: Thu, 16 Jan 2020 22:00:21 +0100
Subject: [PATCH] Sign and verify PAC with ticket principal instead of canon
 
Conflict: NA 
Reference: https://git.samba.org/samba.git/?p=samba.git;a=patch;h=34347586375dea9b615fb6a0218bcb5927031e4d

principal

With MIT library 1.18 the KDC no longer set
KRB5_KDB_FLAG_CANONICALIZE for enterprise principals which allows
us to not canonicalize them (like in Windows / Heimdal).

However, it now breaks the PAC signature verification as it was
wrongly done using canonical client rather than ticket client name.

Signed-off-by: Isaac Boukris <iboukris@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>
---
 source4/kdc/mit-kdb/kdb_samba_policies.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/source4/kdc/mit-kdb/kdb_samba_policies.c b/source4/kdc/mit-kdb/kdb_samba_policies.c
index 586cf81451d..2eec496fa92 100644
--- a/source4/kdc/mit-kdb/kdb_samba_policies.c
+++ b/source4/kdc/mit-kdb/kdb_samba_policies.c
@@ -301,20 +301,12 @@ krb5_error_code kdb_samba_db_sign_auth_data(krb5_context context,
 					    krb5_authdata **tgt_auth_data,
 					    krb5_authdata ***signed_auth_data)
 {
-	krb5_const_principal ks_client_princ;
 	krb5_authdata **authdata = NULL;
 	krb5_boolean is_as_req;
 	krb5_error_code code;
 	krb5_pac pac = NULL;
 	krb5_data pac_data;
 
-	/* Prefer canonicalised name from client entry */
-	if (client != NULL) {
-		ks_client_princ = client->princ;
-	} else {
-		ks_client_princ = client_princ;
-	}
-
 	is_as_req = ((flags & KRB5_KDB_FLAG_CLIENT_REFERRALS_ONLY) != 0);
 
 	if (is_as_req && (flags & KRB5_KDB_FLAG_INCLUDE_PAC)) {
@@ -354,7 +346,7 @@ krb5_error_code kdb_samba_db_sign_auth_data(krb5_context context,
 	if (!is_as_req) {
 		code = ks_verify_pac(context,
 				     flags,
-				     ks_client_princ,
+				     client_princ,
 				     client,
 				     server,
 				     krbtgt,
@@ -381,7 +373,7 @@ krb5_error_code kdb_samba_db_sign_auth_data(krb5_context context,
 		goto done;
 	}
 
-	code = krb5_pac_sign(context, pac, authtime, ks_client_princ,
+	code = krb5_pac_sign(context, pac, authtime, client_princ,
 			server_key, krbtgt_key, &pac_data);
 	if (code != 0) {
 		DBG_ERR("krb5_pac_sign failed: %d\n", code);
-- 
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