freebsd-src/crypto/heimdal/admin/change.c
Cy Schubert ed549cb0c5 heimdal: Fix multiple security vulnerabilities
The following issues are patched:

 - CVE-2022-42898 PAC parse integer overflows
 - CVE-2022-3437 Overflows and non-constant time leaks in DES{,3} and arcfour
 - CVE-2021-44758 NULL dereference DoS in SPNEGO acceptors
 - CVE-2022-44640 Heimdal KDC: invalid free in ASN.1 codec

    Note that CVE-2022-44640 is a severe vulnerability, possibly a 10.0
    on the Common Vulnerability Scoring System (CVSS) v3, as we believe
    it should be possible to get an RCE on a KDC, which means that
    credentials can be compromised that can be used to impersonate
    anyone in a realm or forest of realms.

    Heimdal's ASN.1 compiler generates code that allows specially
    crafted DER encodings of CHOICEs to invoke the wrong free function
    on the decoded structure upon decode error.  This is known to impact
    the Heimdal KDC, leading to an invalid free() of an address partly
    or wholly under the control of the attacker, in turn leading to a
    potential remote code execution (RCE) vulnerability.

    This error affects the DER codec for all extensible CHOICE types
    used in Heimdal, though not all cases will be exploitable.  We have
    not completed a thorough analysis of all the Heimdal components
    affected, thus the Kerberos client, the X.509 library, and other
    parts, may be affected as well.

    This bug has been in Heimdal's ASN.1 compiler since 2005, but it may
    only affect Heimdal 1.6 and up.  It was first reported by Douglas
    Bagnall, though it had been found independently by the Heimdal
    maintainers via fuzzing a few weeks earlier.

    While no zero-day exploit is known, such an exploit will likely be
    available soon after public disclosure.

 - CVE-2019-14870: Validate client attributes in protocol-transition
 - CVE-2019-14870: Apply forwardable policy in protocol-transition
 - CVE-2019-14870: Always lookup impersonate client in DB

Sponsored by:	so (philip)
Obtained from:	so (philip)
Tested by:	philip, cy
MFC after:	immediately
2022-11-15 13:12:37 -08:00

252 lines
6.6 KiB
C

/*
* Copyright (c) 1997-2005 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "ktutil_locl.h"
RCSID("$Id$");
static krb5_error_code
change_entry (krb5_keytab keytab,
krb5_principal principal, krb5_kvno kvno,
const char *realm, const char *admin_server, int server_port)
{
krb5_error_code ret;
kadm5_config_params conf;
void *kadm_handle;
char *client_name;
krb5_keyblock *keys;
int num_keys;
int i;
ret = krb5_unparse_name (context, principal, &client_name);
if (ret) {
krb5_warn (context, ret, "krb5_unparse_name");
return ret;
}
memset (&conf, 0, sizeof(conf));
if(realm == NULL)
realm = krb5_principal_get_realm(context, principal);
conf.realm = strdup(realm);
if (conf.realm == NULL) {
free (client_name);
krb5_set_error_message(context, ENOMEM, "malloc failed");
return ENOMEM;
}
conf.mask |= KADM5_CONFIG_REALM;
if (admin_server) {
conf.admin_server = strdup(admin_server);
if (conf.admin_server == NULL) {
free(client_name);
free(conf.realm);
krb5_set_error_message(context, ENOMEM, "malloc failed");
return ENOMEM;
}
conf.mask |= KADM5_CONFIG_ADMIN_SERVER;
}
if (server_port) {
conf.kadmind_port = htons(server_port);
conf.mask |= KADM5_CONFIG_KADMIND_PORT;
}
ret = kadm5_init_with_skey_ctx (context,
client_name,
keytab_string,
KADM5_ADMIN_SERVICE,
&conf, 0, 0,
&kadm_handle);
free(conf.admin_server);
free(conf.realm);
if (ret) {
krb5_warn (context, ret,
"kadm5_c_init_with_skey_ctx: %s:", client_name);
free (client_name);
return ret;
}
ret = kadm5_randkey_principal (kadm_handle, principal, &keys, &num_keys);
kadm5_destroy (kadm_handle);
if (ret) {
krb5_warn(context, ret, "kadm5_randkey_principal: %s:", client_name);
free (client_name);
return ret;
}
free (client_name);
for (i = 0; i < num_keys; ++i) {
krb5_keytab_entry new_entry;
new_entry.principal = principal;
new_entry.timestamp = time (NULL);
new_entry.vno = kvno + 1;
new_entry.keyblock = keys[i];
ret = krb5_kt_add_entry (context, keytab, &new_entry);
if (ret)
krb5_warn (context, ret, "krb5_kt_add_entry");
krb5_free_keyblock_contents (context, &keys[i]);
}
return ret;
}
/*
* loop over all the entries in the keytab (or those given) and change
* their keys, writing the new keys
*/
struct change_set {
krb5_principal principal;
krb5_kvno kvno;
};
int
kt_change (struct change_options *opt, int argc, char **argv)
{
krb5_error_code ret;
krb5_keytab keytab;
krb5_kt_cursor cursor;
krb5_keytab_entry entry;
int i, j, max;
struct change_set *changeset;
int errors = 0;
if((keytab = ktutil_open_keytab()) == NULL)
return 1;
j = 0;
max = 0;
changeset = NULL;
ret = krb5_kt_start_seq_get(context, keytab, &cursor);
if(ret){
krb5_warn(context, ret, "%s", keytab_string);
goto out;
}
while((ret = krb5_kt_next_entry(context, keytab, &entry, &cursor)) == 0) {
int add = 0;
for (i = 0; i < j; ++i) {
if (krb5_principal_compare (context, changeset[i].principal,
entry.principal)) {
if (changeset[i].kvno < entry.vno)
changeset[i].kvno = entry.vno;
break;
}
}
if (i < j) {
krb5_kt_free_entry (context, &entry);
continue;
}
if (argc == 0) {
add = 1;
} else {
for (i = 0; i < argc; ++i) {
krb5_principal princ;
ret = krb5_parse_name (context, argv[i], &princ);
if (ret) {
krb5_warn (context, ret, "%s", argv[i]);
continue;
}
if (krb5_principal_compare (context, princ, entry.principal))
add = 1;
krb5_free_principal (context, princ);
}
}
if (add) {
if (j >= max) {
void *tmp;
max = max(max * 2, 1);
tmp = realloc (changeset, max * sizeof(*changeset));
if (tmp == NULL) {
krb5_kt_free_entry (context, &entry);
krb5_warnx (context, "realloc: out of memory");
ret = ENOMEM;
break;
}
changeset = tmp;
}
ret = krb5_copy_principal (context, entry.principal,
&changeset[j].principal);
if (ret) {
krb5_warn (context, ret, "krb5_copy_principal");
krb5_kt_free_entry (context, &entry);
break;
}
changeset[j].kvno = entry.vno;
++j;
}
krb5_kt_free_entry (context, &entry);
}
krb5_kt_end_seq_get(context, keytab, &cursor);
if (ret == KRB5_KT_END) {
for (i = 0; i < j; i++) {
if (verbose_flag) {
char *client_name;
ret = krb5_unparse_name (context, changeset[i].principal,
&client_name);
if (ret) {
krb5_warn (context, ret, "krb5_unparse_name");
} else {
printf("Changing %s kvno %d\n",
client_name, changeset[i].kvno);
free(client_name);
}
}
ret = change_entry (keytab,
changeset[i].principal, changeset[i].kvno,
opt->realm_string,
opt->admin_server_string,
opt->server_port_integer);
if (ret != 0)
errors = 1;
}
} else
errors = 1;
for (i = 0; i < j; i++)
krb5_free_principal (context, changeset[i].principal);
free (changeset);
out:
krb5_kt_close(context, keytab);
return errors;
}