Hello Robert, or anyone else affected, Accepted cyrus-sasl2 into jammy-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/cyrus- sasl2/2.1.27+dfsg2-3ubuntu1.1 in a few hours, and then in the -proposed repository.
Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users. If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed- jammy to verification-done-jammy. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification- failed-jammy. In either case, without details of your testing we will not be able to proceed. Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping! N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days. ** Changed in: cyrus-sasl2 (Ubuntu Jammy) Status: In Progress => Fix Committed ** Tags added: verification-needed verification-needed-jammy -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to cyrus-sasl2 in Ubuntu. https://bugs.launchpad.net/bugs/1912256 Title: Missing channel binding prevents authentication to ActiveDirectory Status in cyrus-sasl2 package in Ubuntu: Fix Released Status in openldap package in Ubuntu: Fix Released Status in cyrus-sasl2 source package in Jammy: Fix Committed Status in openldap source package in Jammy: Fix Released Bug description: [Impact] When attempting to authenticate against a Windows Active Directory server configured to require SASL channel binding over SSL/TLS ldap connections (ldaps), authentication will fail stating invalid credentials as the cause. This is due to cyrus-sasl2 missing the sasl channel binding feature of GSSAPI/GSS-SPNEGO. Furthermore, for interoperability with Windows Active Directory Server, it's necessary to be able to set the SASL SSF (security strength factor) to 0 (zero) when it's used over an already encrypted connection like ldaps. To fix these issues, these items are added as patches from a set of upstream commits. [Test Plan] To reproduce this issue, a machine running Windows with Active Directory must be available over the network. As an example, for Windows Server 2019 Evaluation: The ISO can be downloaded from https://www.microsoft.com/en-us/evalcenter/download-windows-server-2019 Install Windows Server, Active Directory, and Certificate Services, then add the following registry changes from https://support.microsoft.com/en-us/topic/2020-ldap-channel-binding-and-ldap-signing-requirements-for-windows-kb4520412-ef185fb8-00f7-167d-744c-f299a66fc00a [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters] "ldapserverintegrity"=dword:00000002 "LdapEnforceChannelBinding"=dword:00000002 Also enable LDAP logging for Active Directory: Reg Add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Diagnostics /v "16 LDAP Interface Events" /t REG_DWORD /d 2 With the Windows machine available, set up an Ubuntu system on a network that can reach the Windows server. This works best and with less configuration needed if the Windows server is acting as DNS and DHCP server for that network. Install packages with: $ sudo apt install ldap-utils libsasl2-modules-gssapi-mit krb5-user When the Configuring Kerberos Authentication prompt shows up, use the realm of the Windows Server. If prompted, use the windows server IP for the Kerberos KDC and admin servers. Save the Windows Server AD CA certificate file as /usr/local/share/ca-certificates/ad-ca.crt then run $ sudo update-ca-certificates In /etc/ldap/ldap.conf set BASE dc={REALM NAME} # split the domain components like dc=example,dc=com URI ldaps://{WINDOWS SERVER MACHINE NAME}.{REALM NAME} With Ubuntu set up, the actual test can be run: $ kinit Enter Password $ ldapwhoami -Y GSSAPI -O maxssf=0 -o SASL_CBINDING=tls-endpoint Prior to the fix, this would display the following: SASL/GSSAPI authentication started ldap_sasl_interactive_bind_s: Invalid credentials (49) additional info: 80090346: LdapErr: DSID-..., comment: AcceptSecurityContext error, data 80090346, v4563 With the fix, the authentication will display the user information. The same happens with $ ldapwhoami -Y GSS-SPNEGO -O maxssf=0 -o SASL_CBINDING=tls-endpoint SASL/GSS-SPNEGO authentication started ldap_sasl_interactive_bind_s: Invalid credentials (49) additional info: 80090346: LdapErr: DSID-..., comment: AcceptSecurityContext error, data 80090346, v4563 [Where problems could occur] Based on the patches added, any problems that show up would likely occour either in the gssapi plugin or the SASL2 macros. The two files changed are plugins/gssapi.c and m4/sasl2.m4, along with some tests. There are various situations apart from this one in which GSS-API can be used, and this change may affect the way some of these interactions over the network are handled. In parallel with this SRU, we tested, in jammy, cyrus-imapd server and gssapi authentication over tls, with and without this updated sasl package. Using as a client thunderbird, imtest (from cyrus-imapd- clients), curl (it has imap support), mutt, evolution. All authenticated without issues. Also postfix with gssapi authentication was tested, and also worked. [Other Info] This issue was fixed in kinetic in version 2.1.28+dfsg-6ubuntu2 This SRU is also pulling in the new DEP8 tests in the kinetic package for cyrus-sasl2. The only changes made to those tests are the list of mechanisms to test, which is slightly smaller in jammy, and an extra package to install for one of the tests due to packaging differences in jammy wrt kinetic. [Original Description] > Are you uncertain if your issue is really a bug? Effect is an authentication error. Root case is a "missing feature" (see below) and requires updating dependencies, downporting. > If you are certain this is a bug please include the source package the bug is in. It's in the interaction between three libraries: openldap, cyrus-sasl, krb5 > 1) The release of Ubuntu you are using, via 'lsb_release -rd' or System -> About Ubuntu Broken in 18.04 and also in 20.10 (I guess it's also broken in anything inbetween) > 2) The version of the package you are using, via 'apt-cache policy pkgname' or by checking in Software Center libsasl2-modules-gssapi-mit: 2.1.27+dfsg-2ubuntu1 ldap-utils: 2.4.53+dfsg-1ubuntu1.2 libgssapi-krb5-2: 1.17-10ubuntu0.1 > 3) What you expected to happen # kinit $ export LDAPSASL_CBINDING=tls-endpoint $ ldapwhoami -O minssf=0,maxssf=0 -N -Y GSSAPI -H ldaps://<DC-fqdn> SASL/GSSAPI authentication started SASL username: <some-username> SASL SSF: 0 u:<some-username> > 4) What happened instead SASL/GSSAPI authentication started ldap_sasl_interactive_bind_s: Invalid credentials (49) additional info: 80090346: LdapErr: DSID-0C090597, comment: AcceptSecurityContext error, data 80090346, v4563 --------------- Microsoft ActiveDirectory has "LDAP Channel Binding" and recommends activating this as a required feature. See https://access.redhat.com/articles/4661861 Authentication to any AD DC which has mandatory channel binding fails. Channel binding requires at least an update to cyrus-sasl, which is not in any release as far as I can see: https://github.com/cyrusimap/cyrus- sasl/commit/975edbb69070eba6b035f08776de771a129cfb57 It also needs this commit in openldap: https://git.openldap.org/openldap/openldap/-/commit/3cd50fa8b32a21040a9892e2a8a7a9dfc7541ce6 Which as far as I can tell is v2.5 (branch OPENLDAP_REL_ENG_2_5). RH also mentions it needs up-to-date krb5 libraries, but I can't tell what minimum version this needs. I can build all libraries from source, current master (except for krb5 where I've used 1.18.3) and can confirm that channel binding works when using those libraries. I'm not sure if Samba is affected, but at least adcli, ldap-utils, and I would guess by extension also SSSD and realmd. 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