summaryrefslogtreecommitdiffstats
path: root/daemons/ipa-slapi-plugins/ipa-lockout/ipa_lockout.c
blob: fea997d79825e05a6ffe4bf65e22821948794ff3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
/** BEGIN COPYRIGHT BLOCK
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Additional permission under GPLv3 section 7:
 *
 * In the following paragraph, "GPL" means the GNU General Public
 * License, version 3 or any later version, and "Non-GPL Code" means
 * code that is governed neither by the GPL nor a license
 * compatible with the GPL.
 *
 * You may link the code of this Program with Non-GPL Code and convey
 * linked combinations including the two, provided that such Non-GPL
 * Code only links to the code of this Program through those well
 * defined interfaces identified in the file named EXCEPTION found in
 * the source code files (the "Approved Interfaces"). The files of
 * Non-GPL Code may instantiate templates or use macros or inline
 * functions from the Approved Interfaces without causing the resulting
 * work to be covered by the GPL. Only the copyright holders of this
 * Program may make changes or additions to the list of Approved
 * Interfaces.
 *
 * Copyright (C) 2010 Red Hat, Inc.
 * All rights reserved.
 * END COPYRIGHT BLOCK **/

/**
 * IPA Lockout plug-in
 *
 * Update the Kerberos lockout variables on LDAP binds.
 *
 */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <time.h>
#include "slapi-plugin.h"
#include "nspr.h"

#include "util.h"

#define IPALOCKOUT_PLUGIN_NAME "ipa-lockout-plugin"
#define IPALOCKOUT_PLUGIN_VERSION 0x00010000

#define IPA_PLUGIN_NAME IPALOCKOUT_PLUGIN_NAME

#define IPALOCKOUT_FEATURE_DESC      "IPA Lockout"
#define IPALOCKOUT_PLUGIN_DESC       "IPA Lockout plugin"
#define IPALOCKOUT_POSTOP_DESC       "IPA Lockout postop plugin"
#define IPALOCKOUT_PREOP_DESC        "IPA Lockout preop plugin"

static Slapi_PluginDesc pdesc = {
    IPALOCKOUT_FEATURE_DESC,
    "Red Hat, Inc.",
    "1.0",
    IPALOCKOUT_PLUGIN_DESC
};

struct ipa_context {
    bool disable_last_success;
    bool disable_lockout;
};

static void *_PluginID = NULL;
static char *_PluginDN = NULL;

static int g_plugin_started = 0;

static struct ipa_context *global_ipactx = NULL;

#define GENERALIZED_TIME_LENGTH 15

/**
 *
 * management functions
 *
 */
int ipalockout_init(Slapi_PBlock * pb);
static int ipalockout_start(Slapi_PBlock * pb);
static int ipalockout_close(Slapi_PBlock * pb);
static int ipalockout_postop_init(Slapi_PBlock * pb);
static int ipalockout_preop_init(Slapi_PBlock * pb);

/**
 *
 * the ops (where the real work is done)
 *
 */
static int ipalockout_postop(Slapi_PBlock *pb);
static int ipalockout_preop(Slapi_PBlock *pb);

/**
 *
 * Get the plug-in version
 *
 */
int ipalockout_version(void)
{
    return IPALOCKOUT_PLUGIN_VERSION;
}

/**
 * Plugin identity mgmt
 */
void setPluginID(void *pluginID)
{
    _PluginID = pluginID;
}

void *getPluginID(void)
{
    return _PluginID;
}

void setPluginDN(char *pluginDN)
{
    _PluginDN = pluginDN;
}

char *getPluginDN(void)
{
    return _PluginDN;
}

static int
ipalockout_get_global_config(struct ipa_context *ipactx)
{
    Slapi_Value *value = NULL;
    Slapi_Attr *attr = NULL;
    char *dn = NULL;
    char *basedn = NULL;
    Slapi_DN *sdn;
    Slapi_Entry *config_entry;
    int ret;

    /* Get cn=config so we can get the default naming context */
    sdn = slapi_sdn_new_dn_byref("cn=config");

    ret = slapi_search_internal_get_entry(sdn, NULL, &config_entry,
              getPluginID());

    slapi_sdn_free(&sdn);

    if (ret) {
        goto done;
    }

    basedn = slapi_entry_attr_get_charptr(config_entry,
        "nsslapd-defaultnamingcontext");

    slapi_entry_free(config_entry);

    if (!basedn) {
        goto done;
    }

    ret = asprintf(&dn, "cn=ipaConfig,cn=etc,%s", basedn);
    if (ret == -1) {
        LOG_OOM();
        ret = LDAP_OPERATIONS_ERROR;
        goto done;
    }

    sdn = slapi_sdn_new_dn_byref(dn);

    ret = slapi_search_internal_get_entry(sdn, NULL, &config_entry,
              getPluginID());

    slapi_sdn_free(&sdn);

    if (ret) {
        goto done;
    }

    ret = slapi_entry_attr_find(config_entry, "ipaConfigString", &attr);
    if (ret == -1) {
        /* no config, nothing to do */
        ret = 0;
        goto done;
    }

    ret = slapi_attr_first_value(attr, &value);
    while (ret != -1) {
        const struct berval *val;

        val = slapi_value_get_berval(value);
        if (!val) {
            ret = LDAP_OPERATIONS_ERROR;
            slapi_value_free(&value);
            goto done;
        }

        if (strncasecmp("KDC:Disable Last Success",
                        val->bv_val, val->bv_len) == 0) {
            ipactx->disable_last_success = true;
        }
        else if (strncasecmp("KDC:Disable Lockout",
                        val->bv_val, val->bv_len) == 0) {
            ipactx->disable_lockout = true;
        }

        ret = slapi_attr_next_value(attr, ret, &value);
    }
    slapi_value_free(&value);

    ret = 0;

done:
    if (config_entry)
        slapi_entry_free(config_entry);
    free(dn);
    free(basedn);
    return ret;
}

int
ipalockout_init(Slapi_PBlock *pb)
{
    int status = EOK;
    char *plugin_identity = NULL;

    LOG_TRACE("--in-->\n");

    slapi_pblock_get(pb, SLAPI_PLUGIN_IDENTITY, &plugin_identity);
    PR_ASSERT(plugin_identity);
    setPluginID(plugin_identity);

    if (slapi_pblock_set(pb, SLAPI_PLUGIN_VERSION,
                         SLAPI_PLUGIN_VERSION_01) != 0 ||
        slapi_pblock_set(pb, SLAPI_PLUGIN_START_FN,
                         (void *) ipalockout_start) != 0 ||
        slapi_pblock_set(pb, SLAPI_PLUGIN_CLOSE_FN,
                         (void *) ipalockout_close) != 0 ||
        slapi_pblock_set(pb, SLAPI_PLUGIN_DESCRIPTION,
                         (void *) &pdesc) != 0 ||
        slapi_register_plugin("postoperation",
                              1,
                              "ipalockout_init",
                              ipalockout_postop_init,
                              IPALOCKOUT_POSTOP_DESC,
                              NULL,
                              plugin_identity
        ) ||
        slapi_register_plugin("preoperation",
                              1,
                              "ipalockout_init",
                              ipalockout_preop_init,
                              IPALOCKOUT_PREOP_DESC,
                              NULL,
                              plugin_identity
        )
        ) {
        LOG_FATAL("failed to register plugin\n");
        status = EFAIL;
    }

    LOG_TRACE("<--out--\n");
    return status;
}

static int
ipalockout_postop_init(Slapi_PBlock *pb)
{
    int status = EOK;

    if (slapi_pblock_set(pb, SLAPI_PLUGIN_VERSION,
                         SLAPI_PLUGIN_VERSION_01) != 0 ||
        slapi_pblock_set(pb, SLAPI_PLUGIN_DESCRIPTION,
                         (void *) &pdesc) != 0 ||
        slapi_pblock_set(pb, SLAPI_PLUGIN_POST_BIND_FN,
                         (void *) ipalockout_postop) != 0) {
        status = EFAIL;
    }

    return status;
}

static int
ipalockout_preop_init(Slapi_PBlock *pb)
{
    int status = EOK;

    if (slapi_pblock_set(pb, SLAPI_PLUGIN_VERSION,
                         SLAPI_PLUGIN_VERSION_01) != 0 ||
        slapi_pblock_set(pb, SLAPI_PLUGIN_DESCRIPTION,
                         (void *) &pdesc) != 0 ||
        slapi_pblock_set(pb, SLAPI_PLUGIN_PRE_BIND_FN,
                         (void *) ipalockout_preop) != 0) {
        status = EFAIL;
    }

    return status;
}

static int
ipalockout_start(Slapi_PBlock * pb)
{
    LOG_TRACE("--in-->\n");

    /* Check if we're already started */
    if (g_plugin_started) {
        goto done;
    }

    g_plugin_started = 1;

    global_ipactx = (struct ipa_context *)malloc(sizeof(*global_ipactx));
    global_ipactx->disable_last_success = false;
    global_ipactx->disable_lockout = false;
    ipalockout_get_global_config(global_ipactx);

    LOG("ready for service\n");
    LOG_TRACE("<--out--\n");

done:
    return EOK;
}

static int
ipalockout_close(Slapi_PBlock * pb)
{
    LOG_TRACE( "--in-->\n");

    LOG_TRACE("<--out--\n");

    return EOK;
}

/*
 * In the post-operation we know whether the bind was successful or not
 * so here we handle updating the Kerberos lockout policy attributes.
 */
static int ipalockout_postop(Slapi_PBlock *pb)
{
    char *dn = NULL;
    char *policy_dn = NULL;
    Slapi_Entry *target_entry = NULL;
    Slapi_Entry *policy_entry = NULL;
    Slapi_DN *sdn = NULL;
    Slapi_DN *pdn = NULL;
    Slapi_PBlock *pbtm = NULL;
    Slapi_Mods *smods = NULL;
    Slapi_Value *objectclass = NULL;
    char *errstr = NULL;
    int ldrc, rc = 0;
    int ret = LDAP_SUCCESS;
    unsigned long failedcount = 0;
    char failedcountstr[32];
    int failed_bind = 0;
    struct tm utctime;
    time_t time_now;
    char timestr[GENERALIZED_TIME_LENGTH+1];
    unsigned int failcnt_interval = 0;
    char *lastfail = NULL;
    int tries = 0;
    int failure = 1;

    LOG_TRACE("--in-->\n");

    /* Just bail if we aren't ready to service requests yet. */
    if (!g_plugin_started) {
        goto done;
    }

    if (global_ipactx->disable_lockout) {
        goto done;
    }

    slapi_pblock_get(pb, SLAPI_RESULT_CODE, &rc);

    /* free the dn here */
    if (slapi_pblock_get(pb, SLAPI_CONN_DN, &dn) != 0) {
        LOG_FATAL("Error retrieving bind DN\n");
        ret = LDAP_OPERATIONS_ERROR;
        goto done;
    }

    /* dn will be NULL on failed auth, get the target instead */
    /* don't free this dn */
    if (dn == NULL && rc != LDAP_SUCCESS) {
        failed_bind = 1;
        if (slapi_pblock_get(pb, SLAPI_BIND_TARGET, &dn) != 0) {
            LOG_FATAL("Error retrieving target DN\n");
            ret = LDAP_OPERATIONS_ERROR;
            goto done;
        }
    }

    /* Client is anonymously bound */
    if (dn == NULL) {
        LOG_TRACE("anonymous bind\n");
        goto done;
    }

    /* Get the entry */
    sdn = slapi_sdn_new_dn_byref(dn);
    if (sdn == NULL) {
        LOG_OOM();
        errstr = "Out of memory.\n";
        ret = LDAP_OPERATIONS_ERROR;
        goto done;
    }

    ldrc = slapi_search_internal_get_entry(sdn, NULL, &target_entry,
            getPluginID());

    if (ldrc != LDAP_SUCCESS) {
            LOG_FATAL("Failed to retrieve entry \"%s\": %d\n", dn, ldrc);
            goto done;
    }

    /* Only update kerberos principal entries */
    objectclass = slapi_value_new_string("krbPrincipalAux");
    if ((slapi_entry_attr_has_syntax_value(target_entry, SLAPI_ATTR_OBJECTCLASS, objectclass)) != 1) {
        LOG_TRACE("Not a kerberos user\n");
        slapi_value_free(&objectclass);
        goto done;
    }
    slapi_value_free(&objectclass);

    /* Only update if there is a password policy */
    policy_dn = slapi_entry_attr_get_charptr(target_entry, "krbPwdPolicyReference");
    if (policy_dn == NULL) {
        LOG_TRACE("No kerberos password policy\n");
        goto done;
    } else {
        pdn = slapi_sdn_new_dn_byref(policy_dn);
        ldrc = slapi_search_internal_get_entry(pdn, NULL, &policy_entry,
                getPluginID());
        slapi_sdn_free(&pdn);
        if (ldrc != LDAP_SUCCESS) {
            LOG_FATAL("Failed to retrieve entry \"%s\": %d\n", policy_dn, ldrc);
            errstr = "Failed to retrieve account policy.";
            ret = LDAP_OPERATIONS_ERROR;
            goto done;
        }
    }

    failedcount = slapi_entry_attr_get_ulong(target_entry, "krbLoginFailedCount");
    failcnt_interval = slapi_entry_attr_get_uint(policy_entry, "krbPwdFailureCountInterval");
    lastfail = slapi_entry_attr_get_charptr(target_entry, "krbLastFailedAuth");
    time_now = time(NULL);
    if (lastfail != NULL) {
        struct tm tm;
        int res = 0;

        memset(&tm, 0, sizeof(struct tm));
        res = sscanf(lastfail,
                     "%04u%02u%02u%02u%02u%02u",
                     &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
                     &tm.tm_hour, &tm.tm_min, &tm.tm_sec);

        if (res == 6) {
            tm.tm_year -= 1900;
            tm.tm_mon -= 1;

            if (time_now > timegm(&tm) + failcnt_interval) {
                failedcount = 0;
            }
        }
    }

    while (tries < 5) {
        smods = slapi_mods_new();

        /* On failures try very hard to update the entry so that failures
         * are counted properly. This involves doing a DELETE of the value
         * we expect and an ADD of the new one in the same update. If the
         * record has changed while we were handling the request our
         * update will fail and we will try again.
         *
         * On a successful bind just do a replace and set failurecount to 0.
         */
        if (failed_bind) {
            PR_snprintf(failedcountstr, sizeof(failedcountstr), "%lu", failedcount);
            if (!gmtime_r(&(time_now), &utctime)) {
                errstr = "failed to parse current date (buggy gmtime_r ?)\n";
                LOG_FATAL("%s", errstr);
                ret = LDAP_OPERATIONS_ERROR;
                goto done;
            }
            strftime(timestr, GENERALIZED_TIME_LENGTH+1,
                 "%Y%m%d%H%M%SZ", &utctime);
            slapi_mods_add_string(smods, LDAP_MOD_DELETE, "krbLoginFailedCount", failedcountstr);
            failedcount += 1;
            PR_snprintf(failedcountstr, sizeof(failedcountstr), "%lu", failedcount);
            slapi_mods_add_string(smods, LDAP_MOD_ADD, "krbLoginFailedCount", failedcountstr);
            if (lastfail)
                slapi_mods_add_string(smods, LDAP_MOD_DELETE, "krbLastFailedAuth", lastfail);
            slapi_mods_add_string(smods, LDAP_MOD_ADD, "krbLastFailedAuth", timestr);
        } else {
            PR_snprintf(failedcountstr, sizeof(failedcountstr), "%lu", 0L);
            time_now = time(NULL);
            if (!gmtime_r(&(time_now), &utctime)) {
                errstr = "failed to parse current date (buggy gmtime_r ?)\n";
                LOG_FATAL("%s", errstr);
                ret = LDAP_OPERATIONS_ERROR;
                goto done;
            }
            strftime(timestr, GENERALIZED_TIME_LENGTH+1,
                 "%Y%m%d%H%M%SZ", &utctime);
            slapi_mods_add_string(smods, LDAP_MOD_REPLACE, "krbLoginFailedCount", failedcountstr);
            if (!global_ipactx->disable_last_success) {
                slapi_mods_add_string(smods, LDAP_MOD_REPLACE, "krbLastSuccessfulAuth", timestr);
            }
        }

        pbtm = slapi_pblock_new();
        slapi_modify_internal_set_pb (pbtm, slapi_entry_get_dn_const(target_entry),
        slapi_mods_get_ldapmods_byref(smods),
        NULL, /* Controls */
        NULL, /* UniqueID */
        getPluginID(), /* PluginID */
        0); /* Flags */

        slapi_modify_internal_pb (pbtm);
        slapi_pblock_get(pb, SLAPI_PLUGIN_INTOP_RESULT, &rc);

        if (rc != LDAP_SUCCESS) {
            LOG_TRACE("WARNING: modify error %d on entry '%s'\n",
                      rc, slapi_entry_get_dn_const(target_entry));

            ldrc = slapi_search_internal_get_entry(sdn, NULL, &target_entry,
                    getPluginID());

            if (ldrc != LDAP_SUCCESS) {
                LOG_FATAL("Failed to retrieve entry \"%s\": %d\n", dn, ldrc);
                goto done;
            }
            slapi_mods_free(&smods);
            slapi_pblock_destroy(pbtm);
            if (lastfail) slapi_ch_free_string(&lastfail);
            smods = NULL;
            pbtm = NULL;
            lastfail = NULL;
            tries += 1;
        } else {
            LOG_TRACE("<= apply mods: Successful\n");
            failure = 0;
            break;
        }
    } /* while */

    if (failure) {
        ret = LDAP_OPERATIONS_ERROR;
    }

done:
    if (!failed_bind && dn != NULL) slapi_ch_free_string(&dn);
    slapi_entry_free(target_entry);
    if (policy_dn) {
        slapi_ch_free_string(&policy_dn);
        slapi_entry_free(policy_entry);
    }
    if (sdn) slapi_sdn_free(&sdn);
    if (lastfail) slapi_ch_free_string(&lastfail);
    if (pbtm) slapi_pblock_destroy(pbtm);
    if (smods) slapi_mods_free(&smods);

    LOG("postop returning %d: %s\n", ret, errstr ? errstr : "success\n");

    if (ret) {
        slapi_send_ldap_result(pb, ret, NULL, errstr, 0, NULL);
    }

    LOG_TRACE("<--out--\n");

    return (ret == 0 ? EOK : EFAIL);
}

/*
 * In the pre-op stage the bind hasn't occurred yet. It is here that
 * we do the lockout enforcement.
 */
static int ipalockout_preop(Slapi_PBlock *pb)
{
    char *dn = NULL;
    char *policy_dn = NULL;
    Slapi_Entry *target_entry = NULL;
    Slapi_Entry *policy_entry = NULL;
    Slapi_DN *sdn = NULL;
    Slapi_DN *pdn = NULL;
    Slapi_Value *objectclass = NULL;
    char *errstr = NULL;
    int ldrc = 0;
    int ret = LDAP_SUCCESS;
    unsigned long failedcount = 0;
    time_t time_now;
    unsigned int failcnt_interval = 0;
    unsigned int max_fail = 0;
    unsigned int lockout_duration = 0;
    time_t last_failed = 0;
    char *lastfail = NULL;
    char *unlock_time = NULL;

    LOG_TRACE("--in-->\n");

    /* Just bail if we aren't ready to service requests yet. */
    if (!g_plugin_started) {
        goto done;
    }

    if (global_ipactx->disable_lockout) {
        goto done;
    }

    if (slapi_pblock_get(pb, SLAPI_BIND_TARGET, &dn) != 0) {
        LOG_FATAL("Error retrieving target DN\n");
        ret = LDAP_OPERATIONS_ERROR;
        goto done;
    }

    /* Client is anonymously bound */
    if (dn == NULL) {
        LOG_TRACE("anonymous bind\n");
        goto done;
    }

    /* Get the entry */
    sdn = slapi_sdn_new_dn_byref(dn);
    if (sdn == NULL) {
        LOG_OOM();
        errstr = "Out of memory.\n";
        ret = LDAP_OPERATIONS_ERROR;
        goto done;
    }

    ldrc = slapi_search_internal_get_entry(sdn, NULL, &target_entry,
            getPluginID());

    if (ldrc != LDAP_SUCCESS) {
        LOG_FATAL("Failed to retrieve entry \"%s\": %d\n", dn, ldrc);
        goto done;
    }

    /* Only handle kerberos principal entries */
    objectclass = slapi_value_new_string("krbPrincipalAux");
    if ((slapi_entry_attr_has_syntax_value(target_entry, SLAPI_ATTR_OBJECTCLASS, objectclass)) != 1) {
        LOG_TRACE("Not a kerberos user\n");
        slapi_value_free(&objectclass);
        goto done;
    }
    slapi_value_free(&objectclass);

    /* Only continue if there is a password policy */
    policy_dn = slapi_entry_attr_get_charptr(target_entry, "krbPwdPolicyReference");
    if (policy_dn == NULL) {
        LOG_TRACE("No kerberos password policy\n");
        goto done;
    } else {
        pdn = slapi_sdn_new_dn_byref(policy_dn);
        ldrc = slapi_search_internal_get_entry(pdn, NULL, &policy_entry,
                getPluginID());
        slapi_sdn_free(&pdn);
        if (ldrc != LDAP_SUCCESS) {
            LOG_FATAL("Failed to retrieve entry \"%s\": %d\n", policy_dn, ldrc);
            errstr = "Failed to retrieve account policy.";
            ret = LDAP_OPERATIONS_ERROR;
            goto done;
        }
    }

    failedcount = slapi_entry_attr_get_ulong(target_entry, "krbLoginFailedCount");
    time_now = time(NULL);
    failcnt_interval = slapi_entry_attr_get_uint(policy_entry, "krbPwdFailureCountInterval");
    lastfail = slapi_entry_attr_get_charptr(target_entry, "krbLastFailedAuth");
    unlock_time = slapi_entry_attr_get_charptr(target_entry, "krbLastAdminUnlock");
    if (lastfail != NULL) {
        struct tm tm;
        int res = 0;

        memset(&tm, 0, sizeof(struct tm));
        res = sscanf(lastfail,
                     "%04u%02u%02u%02u%02u%02u",
                     &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
                     &tm.tm_hour, &tm.tm_min, &tm.tm_sec);

        if (res == 6) {
            tm.tm_year -= 1900;
            tm.tm_mon -= 1;

            last_failed = timegm(&tm);
            LOG("%ld > %ld ?\n",
                (long)time_now, (long)last_failed + failcnt_interval);
            LOG("diff %ld\n",
                (long)((last_failed + failcnt_interval) - time_now));
            if (time_now > last_failed + failcnt_interval) {
                failedcount = 0;
            }
        }
        if (unlock_time) {
            time_t unlock;

            memset(&tm, 0, sizeof(struct tm));
            res = sscanf(lastfail,
                         "%04u%02u%02u%02u%02u%02u",
                         &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
                         &tm.tm_hour, &tm.tm_min, &tm.tm_sec);

            if (res == 6) {
                tm.tm_year -= 1900;
                tm.tm_mon -= 1;

                unlock = timegm(&tm);
                if (last_failed <= unlock) {
                    goto done;
                }
            }
            slapi_ch_free_string(&unlock_time);
        }
        slapi_ch_free_string(&lastfail);
    }

    max_fail = slapi_entry_attr_get_uint(policy_entry, "krbPwdMaxFailure");
    if (max_fail == 0) {
        goto done;
    }

    lockout_duration = slapi_entry_attr_get_uint(policy_entry, "krbPwdLockoutDuration");
    if (lockout_duration == 0) {
        errstr = "Entry permanently locked.\n";
        ret = LDAP_UNWILLING_TO_PERFORM;
        goto done;
    }

    if (failedcount > max_fail) {
        if (time_now < last_failed + lockout_duration) {
            /* Too many failures */
            LOG_TRACE("Too many failed logins. %lu out of %d\n", failedcount, max_fail);
            errstr = "Too many failed logins.\n";
            ret = LDAP_UNWILLING_TO_PERFORM;
        }
    }

done:
    slapi_entry_free(target_entry);
    slapi_entry_free(policy_entry);
    if (policy_dn) slapi_ch_free_string(&policy_dn);
    if (sdn) slapi_sdn_free(&sdn);

    LOG("preop returning %d: %s\n", ret, errstr ? errstr : "success\n");

    if (ret) {
        slapi_send_ldap_result(pb, ret, NULL, errstr, 0, NULL);
    }

    LOG_TRACE("<--out--\n");

    return (ret == 0 ? EOK : EFAIL);
}