On 01/07/2014 07:23 AM, Alexander Bokovoy wrote:
> On Mon, 06 Jan 2014, Tomas Babej wrote:
>>
>> On 01/06/2014 12:16 PM, Tomas Babej wrote:
>>> On 04/15/2013 12:43 PM, Tomas Babej wrote:
>>>> On 04/08/2013 03:55 PM, Martin Kosek wrote:
>>>>> On 04/01/2013 09:52 PM, Rob Crittenden wrote:
>>>>>> Tomas Babej wrote:
>>>>>>> On 02/12/2013 06:23 PM, Simo Sorce wrote:
>>>>>>>> On Tue, 2013-02-12 at 18:03 +0100, Tomas Babej wrote:
>>>>>>>>> On 02/12/2013 05:50 PM, Tomas Babej wrote:
>>>>>>>>>> Hi,
>>>>>>>>>>
>>>>>>>>>> This patch adds a check for krbprincipalexpiration attribute to
>>>>>>>>>> pre_bind operation
>>>>>>>>>> in ipa-pwd-extop dirsrv plugin. If the principal is expired,
>>>>>>>>>> auth is
>>>>>>>>>> denied and LDAP_INVALID_CREDENTIALS along with the error
>>>>>>>>>> message is
>>>>>>>>>> sent back to the client. Since krbprincipalexpiration
>>>>>>>>>> attribute is
>>>>>>>>> not
>>>>>>>>>> mandatory, if there is no value set, the check is passed.
>>>>>>>>>>
>>>>>>>>>> https://fedorahosted.org/freeipa/ticket/3305
>>>>>>>> Comments inline.
>>>>>>>>> @@ -1166,6 +1173,29 @@ static int ipapwd_pre_bind(Slapi_PBlock
>>>>>>>>> *pb)
>>>>>>>>>            goto done;
>>>>>>>>>        }
>>>>>>>>> +    /* check the krbPrincipalExpiration attribute is present */
>>>>>>>>> +    ret = slapi_entry_attr_find(entry, "krbPrincipalExpiration",
>>>>>>>>> &attr);
>>>>>>>>> +    if (!ret) {
>>>>>>>> ret is not a boolean so probably better ti use (ret != 0)
>>>>>>>>
>>>>>>>>> +        /* if it is, check whether the principal has not
>>>>>>>>> expired */
>>>>>>>>> +
>>>>>>>>> +        principal_expire = slapi_entry_attr_get_charptr(entry,
>>>>>>>>> +                               "krbprincipalexpiration");
>>>>>>>>> +        memset(&expire_tm, 0, sizeof (expire_tm));
>>>>>>>>> +
>>>>>>>>> +        if (strptime(principal_expire, "%Y%m%d%H%M%SZ",
>>>>>>>>> &expire_tm)){
>>>>>>>> style issue missing space between ) and {
>>>>>>>>
>>>>>>>>> +            expire_time = mktime(&expire_tm);
>>>>>>>>> +            /* this might have overflown on 32-bit system */
>>>>>>>> This comment does not help to point out what you want to put in
>>>>>>>> evidence.
>>>>>>>> if there is an overflow what is the consequence ? Or does it
>>>>>>>> mean the
>>>>>>>> next condition is taking that into account ?
>>>>>>> Yeah, this was rather ill-worded. Replaced by a rather verbose
>>>>>>> comment that hopefully clears things out.
>>>>>>>>> +            if (current_time > expire_time && expire_time > 0){
>>>>>>>> style issue missing space between ) and {
>>>>>>>>
>>>>>>>>> +                LOG_FATAL("kerberos principal has expired in
>>>>>>>>> user
>>>>>>>>> entry: %s\n",
>>>>>>>>> +                          dn);
>>>>>>>> I think a better phrasing would be: "The kerberos principal on
>>>>>>>> %s is
>>>>>>>> expired\n"
>>>>>>>>
>>>>>>>>> +                errMesg = "Kerberos principal has expired.";
>>>>>>>> s/has/is/
>>>>>>>>
>>>>>>>> The rest looks good to me.
>>>>>>>>
>>>>>>>> Simo.
>>>>>>> Styling issues fixed and updated patch attached :)
>>>>>> Small nit, the expiration error should probably use 'in' not 'on'.
>>>>>>
>>>>>> I'm not sure LDAP_INVALID_CREDENTIALS is the right return code. This
>>>>>> implies
>>>>>> that the password is wrong. I think that LDAP_UNWILLING_TO_PERFORM
>>>>>> is probably
>>>>>> more correct here. It is what we return on other policy failures.
>>>>>>
>>>>>> rob
>>>>>>
>>>>> Additional findings:
>>>>>
>>>>> 1) Lets not try to get current_time every time, but only when its
>>>>> needed (i.e.
>>>>> krbPrincipalExpiration is set) - AFAIK, it is not so cheap operation:
>>>>>
>>>>> +    /* get current time*/
>>>>> +    current_time = time(NULL);
>>>>>
>>>>> 2) Why using slapi_entry_attr_get_charptr and thus let 389-ds find
>>>>> the
>>>>> attribute again when we already have a pointer for the attribute?
>>>>> Would
>>>>> slapi_attr_first_value following slapi_entry_attr_find be faster
>>>>> approach?
>>>>>
>>>>> +    ret = slapi_entry_attr_find(entry, "krbPrincipalExpiration",
>>>>> &attr);
>>>>> +    if (ret != 0) {
>>>>> +        /* if it is, check whether the principal has not expired */
>>>>> +
>>>>> +        principal_expire = slapi_entry_attr_get_charptr(entry,
>>>>> +                               "krbprincipalexpiration");
>>>>>
>>>>> This way, we would not create a copy of this attribute value - we do
>>>>> not need a
>>>>> copy, we just do check against it.
>>>>>
>>>>>
>>>>> 3) Shouldn't we return -1 in the end when the auth fails? We do that
>>>>> in other
>>>>> pre_callbacks. Otherwise we just return 0 (success):
>>>>>
>>>>> +    if (auth_failed){
>>>>> +        slapi_send_ldap_result(pb, LDAP_INVALID_CREDENTIALS, NULL,
>>>>> errMesg,
>>>>> +                               0, NULL);
>>>>> +    }
>>>>> +
>>>>>       return 0;
>>>>>
>>>>> Martin
>>>> Thank you both for the review. I updated and retested the patch, with
>>>> your suggestions incorporated.
>>>>
>>>> Tomas
>>>>
>>> I rebased the patch on top of current master.
>>>
>>> Bumping, since this is planned as part of 3.4 (and there were some
>>> requests for this feature).
>>>
>>> Tomas
>>>
>>
>> I updated the commit message to reflect better what the current version
>> of the patch implements.
>>
>> Tomas
>
>>> From a93d1ec3ca8c7b6e8e754b474257695ba9018e07 Mon Sep 17 00:00:00 2001
>> From: Tomas Babej <tba...@redhat.com>
>> Date: Mon, 6 Jan 2014 12:11:24 +0100
>> Subject: [PATCH] ipa-pwd-extop: Deny LDAP binds for user accounts
>> with expired
>> principal
>>
>> Adds a check for krbprincipalexpiration attribute to pre_bind operation
>> in ipa-pwd-extop dirsrv plugin. If the principal is expired, auth is
>> denied and LDAP_UNWILLING_TO_PERFORM along with the error message is
>> sent back to the client. Since krbprincipalexpiration attribute is not
>> mandatory, if there is no value set, the check is passed.
>>
>> https://fedorahosted.org/freeipa/ticket/3305
>> ---
>> daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c | 45
>> ++++++++++++++++++++++-
>> 1 file changed, 44 insertions(+), 1 deletion(-)
>>
>> diff --git a/daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c
>> b/daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c
>> index
>> ef37b5e173359f9404b241c12d8a6dc6e77da128..568cba7189d1575d030b043daee61f713e9bac5f
>> 100644
>> --- a/daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c
>> +++ b/daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c
>> @@ -1389,13 +1389,17 @@ static int ipapwd_pre_bind(Slapi_PBlock *pb)
>>     Slapi_Value *value = NULL;
>>     Slapi_Attr *attr = NULL;
>>     struct tm expire_tm;
>> +    time_t current_time;
>> +    time_t expire_time;
>>     char *errMesg = "Internal operations error\n"; /* error message */
>>     char *expire = NULL; /* passwordExpirationTime attribute value */
>> +    char *principal_expire = NULL; /* krbPrincipalExpiration
>> attribute value */
>>     char *dn = NULL; /* bind DN */
>>     Slapi_Value *objectclass;
>>     int method; /* authentication method */
>>     int ret = 0;
>>     char *principal = NULL;
>> +    bool auth_failed = false;
>>
>>     LOG_TRACE("=>\n");
>>
>> @@ -1422,7 +1426,7 @@ static int ipapwd_pre_bind(Slapi_PBlock *pb)
>>     const char *attrs_list[] = {SLAPI_USERPWD_ATTR,
>> "krbprincipalkey", "uid",
>>                                 "krbprincipalname", "objectclass",
>>                                 "passwordexpirationtime", 
>> "passwordhistory",
>> -                                NULL};
>> +                                "krbprincipalexpiration", NULL};
>>
>>     /* retrieve user entry */
>>     ret = ipapwd_getEntry(dn, &entry, (char **) attrs_list);
>> @@ -1438,6 +1442,39 @@ static int ipapwd_pre_bind(Slapi_PBlock *pb)
>>         goto done;
>>     }
>>
>> +    /* check the krbPrincipalExpiration attribute is present */
>> +    ret = slapi_entry_attr_find(entry, "krbPrincipalExpiration",
>> &attr);
>> +    if (ret == 0) {
>> +        ret = slapi_attr_first_value(attr, &value);
>> +
>> +        if (ret == 0) {
>> +            /* if it is, check whether the principal has not expired */
>> +            principal_expire = slapi_value_get_string(value);
>> +            memset(&expire_tm, 0, sizeof (expire_tm));
>> +
>> +            if (strptime(principal_expire, "%Y%m%d%H%M%SZ",
>> &expire_tm)) {
>> +                expire_time = mktime(&expire_tm);
>> +
>> +                /* get current time */
>> +                current_time = time(NULL);
>> +
>> +                /* mktime returns -1 if the tm struct cannot be
>> represented as
>> +                 * as calendar time (seconds since the Epoch). This
>> might
>> +                 * happen with tm structs that are ill-formated or
>> on 32-bit
>> +                 * platforms with dates that would cause overflow
>> +                 * (year 2038 and later).
>> +                 * In such cases, skip the expiration check. */
>> +
>> +                if (current_time > expire_time && expire_time > 0) {
>> +                    LOG_FATAL("kerberos principal in %s is
>> expired\n", dn);
>> +                    errMesg = "Kerberos principal is expired.";
>> +                    auth_failed = true;
>> +                    goto done;
>> +                    }
>> +                }
> I think indenting is broken for these two brackets.
>
>

Thanks Alexander, fixed.

Updated version attached.

Tomas
>From 86d6564bfed7b88872c643a1b4912c45c5bfb609 Mon Sep 17 00:00:00 2001
From: Tomas Babej <tba...@redhat.com>
Date: Mon, 6 Jan 2014 12:11:24 +0100
Subject: [PATCH] ipa-pwd-extop: Deny LDAP binds for user accounts with expired
 principal

Adds a check for krbprincipalexpiration attribute to pre_bind operation
in ipa-pwd-extop dirsrv plugin. If the principal is expired, auth is
denied and LDAP_UNWILLING_TO_PERFORM along with the error message is
sent back to the client. Since krbprincipalexpiration attribute is not
mandatory, if there is no value set, the check is passed.

https://fedorahosted.org/freeipa/ticket/3305
---
 daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c | 45 ++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c b/daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c
index ef37b5e173359f9404b241c12d8a6dc6e77da128..df74a671c219f9b4aaa407f2ebd68f41669817b4 100644
--- a/daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c
+++ b/daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c
@@ -1389,13 +1389,17 @@ static int ipapwd_pre_bind(Slapi_PBlock *pb)
     Slapi_Value *value = NULL;
     Slapi_Attr *attr = NULL;
     struct tm expire_tm;
+    time_t current_time;
+    time_t expire_time;
     char *errMesg = "Internal operations error\n"; /* error message */
     char *expire = NULL; /* passwordExpirationTime attribute value */
+    char *principal_expire = NULL; /* krbPrincipalExpiration attribute value */
     char *dn = NULL; /* bind DN */
     Slapi_Value *objectclass;
     int method; /* authentication method */
     int ret = 0;
     char *principal = NULL;
+    bool auth_failed = false;
 
     LOG_TRACE("=>\n");
 
@@ -1422,7 +1426,7 @@ static int ipapwd_pre_bind(Slapi_PBlock *pb)
     const char *attrs_list[] = {SLAPI_USERPWD_ATTR, "krbprincipalkey", "uid",
                                 "krbprincipalname", "objectclass",
                                 "passwordexpirationtime",  "passwordhistory",
-                                NULL};
+                                "krbprincipalexpiration", NULL};
 
     /* retrieve user entry */
     ret = ipapwd_getEntry(dn, &entry, (char **) attrs_list);
@@ -1438,6 +1442,39 @@ static int ipapwd_pre_bind(Slapi_PBlock *pb)
         goto done;
     }
 
+    /* check the krbPrincipalExpiration attribute is present */
+    ret = slapi_entry_attr_find(entry, "krbPrincipalExpiration", &attr);
+    if (ret == 0) {
+        ret = slapi_attr_first_value(attr, &value);
+
+        if (ret == 0) {
+            /* if it is, check whether the principal has not expired */
+            principal_expire = slapi_value_get_string(value);
+            memset(&expire_tm, 0, sizeof (expire_tm));
+
+            if (strptime(principal_expire, "%Y%m%d%H%M%SZ", &expire_tm)) {
+                expire_time = mktime(&expire_tm);
+
+                /* get current time */
+                current_time = time(NULL);
+
+                /* mktime returns -1 if the tm struct cannot be represented as
+                 * as calendar time (seconds since the Epoch). This might
+                 * happen with tm structs that are ill-formated or on 32-bit
+                 * platforms with dates that would cause overflow
+                 * (year 2038 and later).
+                 * In such cases, skip the expiration check. */
+
+                if (current_time > expire_time && expire_time > 0) {
+                    LOG_FATAL("kerberos principal in %s is expired\n", dn);
+                    errMesg = "Kerberos principal is expired.";
+                    auth_failed = true;
+                    goto done;
+                }
+            }
+        }
+    }
+
     /* we aren't interested in host principals */
     objectclass = slapi_value_new_string("ipaHost");
     if ((slapi_entry_attr_has_syntax_value(entry, SLAPI_ATTR_OBJECTCLASS, objectclass)) == 1) {
@@ -1560,6 +1597,12 @@ done:
         slapi_entry_free(entry);
     free_ipapwd_krbcfg(&krbcfg);
 
+    if (auth_failed){
+        slapi_send_ldap_result(pb, LDAP_UNWILLING_TO_PERFORM, NULL, errMesg,
+                               0, NULL);
+        return -1;
+    }
+
     return 0;
 }
 
-- 
1.8.4.2

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