Ticket History #6403: kdb5_ldap_util create segfaults when krb5_dbekd_encrypt_key_data() called

I'm seeing a segfault when I run:
kdb5_ldap_util -P test123 -D "cn=Manager,dc=zone,dc=net" -w test123
create -r ZONE.NET -s

Core was generated by `kdb5_ldap_util -P test123 -D
cn=Manager,dc=zone,dc=net -w test123 create -r ZON'.
Program terminated with signal 11, Segmentation fault.

#0 0xfeef873d in krb5_dbekd_encrypt_key_data (kcontext=0x80876c8,
mkey=0x80479e0, dbkey=0x809ac1c, keysalt=0x0,
keyver=1, key_data=0x8098940) at
../../../migrate_bugfix/src/lib/kdb/kdb5.c:3052
3052 status =
(gdb) where
#0 0xfeef873d in krb5_dbekd_encrypt_key_data (kcontext=0x80876c8,
mkey=0x80479e0, dbkey=0x809ac1c, keysalt=0x0,
keyver=1, key_data=0x8098940) at
../../../migrate_bugfix/src/lib/kdb/kdb5.c:3052
#1 0x08057b40 in kdb_ldap_create_principal (context=0x80876c8,
princ=0x8099cc0, op=MASTER_KEY, pblock=0x806ec1c)
at
../../../../../migrate_bugfix/src/plugins/kdb/ldap/ldap_util/kdb5_ldap_realm.c:2503
#2 0x08055ddc in kdb5_ldap_create (argc=2, argv=0x809df88)
at
../../../../../migrate_bugfix/src/plugins/kdb/ldap/ldap_util/kdb5_ldap_realm.c:700
#3 0x08054248 in main (argc=0, argv=0x8047b00)
at
../../../../../migrate_bugfix/src/plugins/kdb/ldap/ldap_util/kdb5_ldap_util.c:614

052 status =
3053 dal_handle->lib_handle->vftabl.dbekd_encrypt_key_data(kcontext,
3054 mkey, dbkey, keysalt, keyver, key_data);

print dal_handle->lib_handle
$1 = 0x0
In src/plugins/kdb/ldap/ldap_util/kdb5_ldap_util.c:main() there is this
to initialize dal_handle:

/* Setup DAL handle to access the database */
dal_handle = calloc((size_t)1, sizeof(kdb5_dal_handle));
if (dal_handle == NULL) {
goto cleanup;
}
dal_handle->db_context = ldap_context;
util_context->dal_handle = dal_handle;
ldap_context = NULL;

db_retval = krb5_ldap_read_server_params(util_context, conf_section,
KRB5_KDB_SRV_TYPE_OTHER);
if (db_retval) {
com_err(progname, db_retval, "while reading ldap configuration");
exit_status++;
goto cleanup;
}

if (cmd->opendb) {
db_retval = krb5_ldap_db_init(util_context, (krb5_ldap_context
*)dal_handle->db_context);
if (db_retval) {
com_err(progname, db_retval, "while initializing database");
exit_status++;
goto cleanup;
}
db_inited = TRUE;
}
(*cmd->func)(cmd_argc, cmd_argv);

Note that dal_handle->lib_handle isn't being initialized.

krb5_dbekd_encrypt_key_data() used to be in lib/krb5/kdb/encrypt_key.c
and did not call dal_handle->lib_handle->vftabl.dbekd_encrypt_key_data().
Now krb5_dbekd_encrypt_key_data() is in src/lib/kdb/kdb5.c and is
calling dal_handle->lib_handle->vftabl.dbekd_encrypt_key_data(). I
think this was introduced by ticket 6313.

The merge of Luke's code in r21690 changed krb5_dbekd_encrypt_key_data
into a virtual function indirecting through lib_handle. This breaks
kdb_ldap_util, which uses a dal_handle with a NULL lib_handle and makes
direct calls to libkdb_ldap and (formerly) non-virtual functions in
libkdb. The reason for using this faked-up dal_handle is that there is
possibly no valid LDAP back end to open.

Sam's opinion is that the best fix is to expose kdb_setup_lib_handle,
thus allowing kdb5_util to set up a dal_handle with a valid lib_handle
(and then fill in the db_context itself, as it does now).

There is also the option of using a krb5_db_create or krb5_db_open
depending on the kdap_ldap_util operation, and adjust the code accordingly.

Rename kdb_setup_lib_handle to krb5_db_setup_lib_handle and export it.
Make kdb5_ldap_util work again by calling this function to set up
dal_handle instead of using one with an uninitialized lib_handle.

It is likely that kdb5_ldap_util will only function given a krb5.conf
which specifies a realm with an LDAP database module as the default
realm. Not sure if that was the case before.


https://github.com/krb5/krb5/commit/bc8407661a88d924bb535d7c08136ebad5be344b
Commit By: ghudson
Revision: 22071
Changed Files:
U trunk/src/include/kdb.h
U trunk/src/lib/kdb/kdb5.c
U trunk/src/lib/kdb/libkdb5.exports
U trunk/src/plugins/kdb/ldap/ldap_util/kdb5_ldap_util.c

pull up r22071 from trunk

------------------------------------------------------------------------
r22071 | ghudson | 2009-03-09 21:28:12 -0400 (Mon, 09 Mar 2009) | 10 lines
Changed paths:
M /trunk/src/include/kdb.h
M /trunk/src/lib/kdb/kdb5.c
M /trunk/src/lib/kdb/libkdb5.exports
M /trunk/src/plugins/kdb/ldap/ldap_util/kdb5_ldap_util.c

ticket: 6403

Rename kdb_setup_lib_handle to krb5_db_setup_lib_handle and export it.
Make kdb5_ldap_util work again by calling this function to set up
dal_handle instead of using one with an uninitialized lib_handle.

It is likely that kdb5_ldap_util will only function given a krb5.conf
which specifies a realm with an LDAP database module as the default
realm. Not sure if that was the case before.

https://github.com/krb5/krb5/commit/1b3caedd1862fe799fae57e04aad3cea746e4a1e
Commit By: tlyu
Revision: 22216
Changed Files:
U branches/krb5-1-7/src/include/kdb.h
U branches/krb5-1-7/src/lib/kdb/kdb5.c
U branches/krb5-1-7/src/lib/kdb/libkdb5.exports
U branches/krb5-1-7/src/plugins/kdb/ldap/ldap_util/kdb5_ldap_util.c