From 6306a2a8697c94f968a02d66204f7d357aa0e7f6 Mon Sep 17 00:00:00 2001

From: Robbie Harwood <rharwood@redhat.com>

Date: Thu, 10 Jan 2019 16:34:54 -0500

Subject: [PATCH] Mark deprecated enctypes when used

Preface ETYPE_DEPRECATED enctypes with "DEPRECATED:" in klist output,

KDC logs, and kadmin interactions.  Also complain in krb5kdc when the

stash file has a deprecated enctype or a deprecated enctype is

requested with -k.

ticket: 8773 (new)

(cherry picked from commit 8d8e68283b599e680f9fe45eff8af397e827bd6c)

---

 src/clients/klist/klist.c      | 14 ++++++++++----

 src/kadmin/cli/kadmin.c        |  6 +++++-

 src/kdc/kdc_util.c             |  9 +++++++++

 src/kdc/main.c                 | 19 +++++++++++++++++++

 src/tests/gssapi/t_enctypes.py | 15 +++++++++------

 src/tests/t_keyrollover.py     |  8 +++++---

 src/tests/t_sesskeynego.py     |  4 ++--

 7 files changed, 59 insertions(+), 16 deletions(-)

diff --git a/src/clients/klist/klist.c b/src/clients/klist/klist.c

index 70adb54e8..8c307151a 100644

--- a/src/clients/klist/klist.c

+++ b/src/clients/klist/klist.c

@@ -571,11 +571,17 @@ static char *

 etype_string(krb5_enctype enctype)

 {

     static char buf[100];

-    krb5_error_code ret;

+    char *bp = buf;

+    size_t deplen, buflen = sizeof(buf);

-    ret = krb5_enctype_to_name(enctype, FALSE, buf, sizeof(buf));

-    if (ret)

-        snprintf(buf, sizeof(buf), "etype %d", enctype);

+    if (krb5int_c_deprecated_enctype(enctype)) {

+        deplen = strlcpy(bp, "DEPRECATED:", buflen);

+        buflen -= deplen;

+        bp += deplen;

+    }

+

+    if (krb5_enctype_to_name(enctype, FALSE, bp, buflen))

+        snprintf(bp, buflen, "etype %d", enctype);

     return buf;

 }

diff --git a/src/kadmin/cli/kadmin.c b/src/kadmin/cli/kadmin.c

index ed581ee79..cc74921bf 100644

--- a/src/kadmin/cli/kadmin.c

+++ b/src/kadmin/cli/kadmin.c

@@ -1451,12 +1451,16 @@ kadmin_getprinc(int argc, char *argv[])

         for (i = 0; i < dprinc.n_key_data; i++) {

             krb5_key_data *key_data = &dprinc.key_data[i];

             char enctype[BUFSIZ], salttype[BUFSIZ];

+            char *deprecated = "";

             if (krb5_enctype_to_name(key_data->key_data_type[0], FALSE,

                                      enctype, sizeof(enctype)))

                 snprintf(enctype, sizeof(enctype), _("<Encryption type 0x%x>"),

                          key_data->key_data_type[0]);

-            printf("Key: vno %d, %s", key_data->key_data_kvno, enctype);

+            if (krb5int_c_deprecated_enctype(key_data->key_data_type[0]))

+                deprecated = "DEPRECATED:";

+            printf("Key: vno %d, %s%s", key_data->key_data_kvno, deprecated,

+                   enctype);

             if (key_data->key_data_ver > 1 &&

                 key_data->key_data_type[1] != KRB5_KDB_SALTTYPE_NORMAL) {

                 if (krb5_salttype_to_string(key_data->key_data_type[1],

diff --git a/src/kdc/kdc_util.c b/src/kdc/kdc_util.c

index f5c581c82..96c88edc1 100644

--- a/src/kdc/kdc_util.c

+++ b/src/kdc/kdc_util.c

@@ -1048,11 +1048,20 @@ static krb5_error_code

 enctype_name(krb5_enctype ktype, char *buf, size_t buflen)

 {

     char *name;

+    size_t len;

     if (buflen == 0)

         return EINVAL;

     *buf = '\0'; /* ensure these are always valid C-strings */

+    if (krb5int_c_deprecated_enctype(ktype)) {

+        len = strlcpy(buf, "DEPRECATED:", buflen);

+        if (len >= buflen)

+            return ENOMEM;

+        buflen -= len;

+        buf += len;

+    }

+

     /* rfc4556 recommends that clients wishing to indicate support for these

      * pkinit algorithms include them in the etype field of the AS-REQ. */

     if (ktype == ENCTYPE_DSA_SHA1_CMS)

diff --git a/src/kdc/main.c b/src/kdc/main.c

index 663fd6303..60092a0df 100644

--- a/src/kdc/main.c

+++ b/src/kdc/main.c

@@ -210,12 +210,23 @@ init_realm(kdc_realm_t * rdp, krb5_pointer aprof, char *realm,

     char                *svalue = NULL;

     const char          *hierarchy[4];

     krb5_kvno       mkvno = IGNORE_VNO;

+    char ename[32];

     memset(rdp, 0, sizeof(kdc_realm_t));

     if (!realm) {

         kret = EINVAL;

         goto whoops;

     }

+

+    if (def_enctype != ENCTYPE_UNKNOWN &&

+        krb5int_c_deprecated_enctype(def_enctype)) {

+        if (krb5_enctype_to_name(def_enctype, FALSE, ename, sizeof(ename)))

+            ename[0] = '\0';

+        fprintf(stderr,

+                _("Requested master password enctype %s in %s is DEPRECATED!"),

+                ename, realm);

+    }

+

     hierarchy[0] = KRB5_CONF_REALMS;

     hierarchy[1] = realm;

     hierarchy[3] = NULL;

@@ -370,6 +381,14 @@ init_realm(kdc_realm_t * rdp, krb5_pointer aprof, char *realm,

         goto whoops;

     }

+    if (krb5int_c_deprecated_enctype(rdp->realm_mkey.enctype)) {

+        if (krb5_enctype_to_name(rdp->realm_mkey.enctype, FALSE, ename,

+                                 sizeof(ename)))

+            ename[0] = '\0';

+        fprintf(stderr, _("Stash file %s uses DEPRECATED enctype %s!"),

+                rdp->realm_stash, ename);

+    }

+

     if ((kret = krb5_db_fetch_mkey_list(rdp->realm_context, rdp->realm_mprinc,

                                         &rdp->realm_mkey))) {

         kdc_err(rdp->realm_context, kret,

diff --git a/src/tests/gssapi/t_enctypes.py b/src/tests/gssapi/t_enctypes.py

index 5d9f80e04..ca3d32d21 100755

--- a/src/tests/gssapi/t_enctypes.py

+++ b/src/tests/gssapi/t_enctypes.py

@@ -9,8 +9,11 @@ from k5test import *

 aes256 = 'aes256-cts-hmac-sha1-96'

 aes128 = 'aes128-cts-hmac-sha1-96'

 des3 = 'des3-cbc-sha1'

+d_des3 = 'DEPRECATED:des3-cbc-sha1'

 des3raw = 'des3-cbc-raw'

+d_des3raw = 'DEPRECATED:des3-cbc-raw'

 rc4 = 'arcfour-hmac'

+d_rc4 = 'DEPRECATED:arcfour-hmac'

 # These tests make assumptions about the default enctype lists, so set

 # them explicitly rather than relying on the library defaults.

@@ -92,7 +95,7 @@ test_err('acc aes128', None, 'aes128-cts',

 # no acceptor subkey will be generated because we can't upgrade to a

 # CFX enctype.

 test('init des3', 'des3', None,

-     tktenc=aes256, tktsession=des3,

+     tktenc=aes256, tktsession=d_des3,

      proto='rfc1964', isubkey=des3raw, asubkey=None)

 # Force the ticket session key to be rc4, so we can test some subkey

@@ -103,7 +106,7 @@ realm.run([kadminl, 'setstr', realm.host_princ, 'session_enctypes', 'rc4'])

 # [aes256 aes128 des3] and the acceptor should upgrade to an aes256

 # subkey.

 test('upgrade noargs', None, None,

-     tktenc=aes256, tktsession=rc4,

+     tktenc=aes256, tktsession=d_rc4,

      proto='cfx', isubkey=rc4, asubkey=aes256)

 # If the initiator won't permit rc4 as a session key, it won't be able

@@ -113,14 +116,14 @@ test_err('upgrade init aes', 'aes', None, 'no support for encryption type')

 # If the initiator permits rc4 but prefers aes128, it will send an

 # upgrade list of [aes128] and the acceptor will upgrade to aes128.

 test('upgrade init aes128+rc4', 'aes128-cts rc4', None,

-     tktenc=aes256, tktsession=rc4,

+     tktenc=aes256, tktsession=d_rc4,

      proto='cfx', isubkey=rc4, asubkey=aes128)

 # If the initiator permits rc4 but prefers des3, it will send an

 # upgrade list of [des3], but the acceptor won't generate a subkey

 # because des3 isn't a CFX enctype.

 test('upgrade init des3+rc4', 'des3 rc4', None,

-     tktenc=aes256, tktsession=rc4,

+     tktenc=aes256, tktsession=d_rc4,

      proto='rfc1964', isubkey=rc4, asubkey=None)

 # If the acceptor permits only aes128, subkey negotiation will fail

@@ -134,14 +137,14 @@ test_err('upgrade acc aes128', None, 'aes128-cts',

 # If the acceptor permits rc4 but prefers aes128, it will negotiate an

 # upgrade to aes128.

 test('upgrade acc aes128 rc4', None, 'aes128-cts rc4',

-     tktenc=aes256, tktsession=rc4,

+     tktenc=aes256, tktsession=d_rc4,

      proto='cfx', isubkey=rc4, asubkey=aes128)

 # In this test, the initiator and acceptor each prefer an AES enctype

 # to rc4, but they can't agree on which one, so no subkey is

 # generated.

 test('upgrade mismatch', 'aes128-cts rc4', 'aes256-cts rc4',

-     tktenc=aes256, tktsession=rc4,

+     tktenc=aes256, tktsession=d_rc4,

      proto='rfc1964', isubkey=rc4, asubkey=None)

 success('gss_krb5_set_allowable_enctypes tests')

diff --git a/src/tests/t_keyrollover.py b/src/tests/t_keyrollover.py

index 7c8d828f0..4af6804f2 100755

--- a/src/tests/t_keyrollover.py

+++ b/src/tests/t_keyrollover.py

@@ -22,8 +22,9 @@ realm.run([kvno, princ1])

 realm.run([kadminl, 'purgekeys', realm.krbtgt_princ])

 # Make sure an old TGT fails after purging old TGS key.

 realm.run([kvno, princ2], expected_code=1)

-msg = 'krbtgt/%s@%s\n\tEtype (skey, tkt): des-cbc-crc, des-cbc-crc' % \

-    (realm.realm, realm.realm)

+ddes = "DEPRECATED:des-cbc-crc"

+msg = 'krbtgt/%s@%s\n\tEtype (skey, tkt): %s, %s' % \

+    (realm.realm, realm.realm, ddes, ddes)

 realm.run([klist, '-e'], expected_msg=msg)

 # Check that new key actually works.

@@ -48,7 +49,8 @@ realm.run([kadminl, 'cpw', '-randkey', '-keepold', '-e', 'aes256-cts',

            realm.krbtgt_princ])

 realm.run([kadminl, 'modprinc', '-kvno', '1', realm.krbtgt_princ])

 out = realm.run([kadminl, 'getprinc', realm.krbtgt_princ])

-if 'vno 1, aes256' not in out or 'vno 1, des3' not in out:

+if 'vno 1, aes256-cts' not in out or \

+   'vno 1, DEPRECATED:des3-cbc-sha1' not in out:

     fail('keyrollover: setup for TGS enctype test failed')

 # Now present the DES3 ticket to the KDC and make sure it's rejected.

 realm.run([kvno, realm.host_princ], expected_code=1)

diff --git a/src/tests/t_sesskeynego.py b/src/tests/t_sesskeynego.py

index 448092387..da02f224a 100755

--- a/src/tests/t_sesskeynego.py

+++ b/src/tests/t_sesskeynego.py

@@ -62,11 +62,11 @@ test_kvno(realm, 'aes128-cts-hmac-sha1-96', 'aes256-cts-hmac-sha1-96')

 # 3b: Negotiate rc4-hmac session key when principal only has aes256 long-term.

 realm.run([kadminl, 'setstr', 'server', 'session_enctypes',

            'rc4-hmac,aes128-cts,aes256-cts'])

-test_kvno(realm, 'arcfour-hmac', 'aes256-cts-hmac-sha1-96')

+test_kvno(realm, 'DEPRECATED:arcfour-hmac', 'aes256-cts-hmac-sha1-96')

 # 3c: Test des-cbc-crc default assumption.

 realm.run([kadminl, 'delstr', 'server', 'session_enctypes'])

-test_kvno(realm, 'des-cbc-crc', 'aes256-cts-hmac-sha1-96')

+test_kvno(realm, 'DEPRECATED:des-cbc-crc', 'aes256-cts-hmac-sha1-96')

 realm.stop()

 # Last go: test that we can disable the des-cbc-crc assumption