Release Notes - Heimdal - Version Heimdal 7.7
PKCS#11 hcrypto back-end
. initialize the p11_module_load function list
. verify that not only is a mechanism present but that its mechanism
info states that it offers the required encryption, decryption or
. Starting with 7.6, Heimdal permitted requesting authenticated
anonymous tickets. However, it did not verify that a KDC in fact
returned an anonymous ticket when one was requested.
. Cease setting the KDCOption reaquest_anonymous flag when issuing
S4UProxy (constrained delegation) TGS requests.
. when the Win2K PKINIT compatibility option is set, do
not require krbtgt otherName to match when validating KDC
. set PKINIT_BTMM flag per Apple implementation
. use memset_s() instead of memset()
. When generating KRB5SignedPath in the AS, use the reply client name
rather than the one from the request, so validation will work
correctly in the TGS.
. allow checksum of PA-FOR-USER to be HMAC_MD5. Even if TGT used
an enctype with a different checksum. Per [MS-SFU] 2.2.1
PA-FOR-USER the checksum is always HMAC_MD5, and that's what
Windows and MIT clients send.
In Heimdal both the client and kdc use instead the
checksum of the TGT, and therefore work with each other
but Windows and MIT clients fail against Heimdal KDC.
Both Windows and MIT KDC would allow any keyed checksum
to be used so Heimdal client work fine against it.
Change Heimdal KDC to allow HMAC_MD5 even for non RC4
based TGT in order to support per-spec clients.
. use memset_s() instead of memset()
. Detect Heimdal 1.0 through 7.6 clients that issue S4UProxy
(constrained delegation) TGS Requests with the request
anonymous flag set. These requests will be treated as
S4UProxy requests and not anonymous requests.
. Set SQLite3 backend default page size to 8KB.
. Add hdb_set_sync() method
. disable HDB sync during database load avoiding unnecessary disk i/o.
. disable HDB sync during receive_everything. Doing an fsync
per-record when receiving the complete HDB is a performance
disaster. Among other things, if the HDB is very large, then
one slave receving a full HDB can cause other slaves to timeout
and, if HDB write activity is high enough to cause iprop log
truncation, then also need full syncs, which leads to a cycle of
full syncs for all slaves until HDB write activity drops.
Allowing the iprop log to be larger helps, but improving
receive_everything() performance helps even more.
. Anonymous PKINIT tickets discard the realm information used
to locate the issuing AS. Store the issuing realm in the
credentials cache in order to locate a KDC which can renew them.
. Do not leak the result of krb5_cc_get_config() when determining
anonymous PKINIT start realm.
. Show transited-policy-checked, ok-as-delegate and anonymous
flags when listing credentials.
. Regenerate certs so that they expire before the 2038 armageddon
so the test suite will pass on 32-bit operating systems until the
underlying issues can be resolved.
. Define _STDC_C11_BCI for memset_s prototype
. Convert from python 2 to python 3
. rename verify-password to verify-password-quality
. hprop default mode is encrypt
. kadmind "all" permission does not include "get-keys"
. verify-password-quality might not be stateless
Building from source:
heimdal-7.7.0.tar.gz and its matching PGP signature file (heimdal-7.7.0.tar.gz.asc) should be downloaded in preference to the GitHub generated "source" archives. The heimdal-7.7.0.tar.gz archive contains the required build products necessary to "configure" and "make".
The GitHub generated "source" archives contain a raw copy of the repository contents for the "heimdal-7.7.0" tag.
Release Notes - Heimdal - Version Heimdal 7.6
CVE-2018-16860 Heimdal KDC: Reject PA-S4U2Self with unkeyed checksum
When the Heimdal KDC checks the checksum that is placed on the
S4U2Self packet by the server to protect the requested principal
against modification, it does not confirm that the checksum
algorithm that protects the user name (principal) in the request
is keyed. This allows a man-in-the-middle attacker who can
intercept the request to the KDC to modify the packet by replacing
the user name (principal) in the request with any desired user
name (principal) that exists in the KDC and replace the checksum
protecting that name with a CRC32 checksum (which requires no
prior knowledge to compute).
This would allow a S4U2Self ticket requested on behalf of user
name (principal) user@EXAMPLE.COM to any service to be changed
to a S4U2Self ticket with a user name (principal) of
Administrator@EXAMPLE.COM. This ticket would then contain the
PAC of the modified user name (principal).
RFC8062 Section 7 requires verification of the PA-PKINIT-KX key exchange
when anonymous PKINIT is used. Failure to do so can permit an active
attacker to become a man-in-the-middle.
- Happy eyeballs: Don't wait for responses from known-unreachable KDCs.
- kdc: check return copy_Realm, copy_PrincipalName, copy_EncryptionKey
. cleanup temporary ccaches
. see man page for "kinit --anonymous" command line syntax change
- kdc: Make anonymous AS-requests more RFC8062-compliant.
- Updated expired test certificates
. PKCS#11 hcrypto backend broken since 7.0.1
. Building with Sun Pro C
- kuser: support authenticated anonymous AS-REQs in kinit
- kdc: support for anonymous TGS-REQs
- kgetcred support for anonymous service tickets
- Support builds with OpenSSL 1.1.1
Building from source:
heimdal-7.6.0.tar.gz and its matching PGP signature file (heimdal-7.6.0.tar.gz) should be downloaded in preference to the GitHub generated "source" archives. The heimdal-7.6.0.tar.gz archive contains the required build products necessary to "configure" and "make".
The GitHub generated "source" archives contain a raw copy of the repository contents for the "heimdal-7.6.0" tag.
This is a security release of Heimdal.
This release patches a critical vulnerability:
CVE-2017-11103: Orpheus' Lyre KDC-REP service name validation In _krb5_extract_ticket() the KDC-REP service name must be obtained from encrypted version stored in 'enc_part' instead of the unencrypted version stored in 'ticket'. Use of the unecrypted version provides an opportunity for successful server impersonation and other attacks. Identified by Jeffrey Altman, Viktor Duchovni and Nico Williams.