FIPs enabled Install Fails
by Entrepreneur AJ
I today spun up a fresh Fedora 38 VPS on Vultr and started the FreeIPA Server install.
This VPS has been switched to FIPs enabled.
I have then tried to install the latest FreeIPA server from DNF without the DNS package.
All was going well until it got to step 17 of 30 and outputted the following:
[17/30]: requesting RA certificate from CA
[error] CalledProcessError: CalledProcessError(Command ['/usr/bin/openssl', 'pkcs12', '-nokeys', '-clcerts', '-in', '/root/ca-agent.p12', '-out', '/var/lib/ipa/tmpfufotvvx', '-passin', 'file:/tmp/tmpwdlfgkkt'] returned non-zero exit status 1: 'Error verifying PKCS12 MAC; no PKCS12KDF support.\nUse -nomacver if MAC verification is not required.\n')
CalledProcessError(Command ['/usr/bin/openssl', 'pkcs12', '-nokeys', '-clcerts', '-in', '/root/ca-agent.p12', '-out', '/var/lib/ipa/tmpfufotvvx', '-passin', 'file:/tmp/tmpwdlfgkkt'] returned non-zero exit status 1: 'Error verifying PKCS12 MAC; no PKCS12KDF support.\nUse -nomacver if MAC verification is not required.\n')
The ipa-server-install command failed. See /var/log/ipaserver-install.log for more information
Any pointers on how to get passed this bit?
10 months, 1 week
How does FreeIPA actually auth client behind the scenes?
by dweller dweller
Hi,
I am interested in understanding the process of user authentication in the FreeIPA WebUI behind the scenes. However, the available information is scattered, and I am struggling to piece it all together. I have attached a diagram illustrating my current understanding, which I know is incorrect. To clarify my confusion, I will break down each point into specific questions:
https://tinyurl.com/freeipa-auth - link to the scheme in draw.io
https://imgur.com/mQEvred - scheme image
1. So user is already sees before him FreeIPA login form. He types his login/password and submits the form
2. Request goes to /ipa/login_password. /ipa/login_password location by itself does not offer much:
<Location "/ipa/session/login_password">
Satisfy Any
Require all granted
</Location>
The interesting part is actually at /ipa location which handled by mod_auth_gssapi:
<Location "/ipa">
AuthType GSSAPI
AuthName "Kerberos Login"
GssapiUseSessions On
Session On
SessionCookieName ipa_session path=/ipa;httponly;secure;
SessionHeader IPASESSION
GssapiSessionKey file:/etc/httpd/alias/ipasession.key
GssapiImpersonate On
GssapiDelegCcacheDir /run/ipa/ccaches
GssapiDelegCcachePerms mode:0660
GssapiDelegCcacheUnique On
GssapiUseS4U2Proxy on
GssapiAllowedMech krb5
Require valid-user
ErrorDocument 401 /ipa/errors/unauthorized.html
Header always append X-Frame-Options DENY
Header always append Content-Security-Policy "frame-ancestors 'none'"
Header unset Set-Cookie
Header unset ETag
FileETag None
</Location>
Here is where things become vague for me. We see *GssapiImpersonate On* and *GssapiUseS4U2Proxy on*.
```
GssapiImpersonate
This option can be used even if AuthType GSSAPI is not used for given Location or LocationMatch, to obtain service ticket for a user that was already authenticated by different module
```
and
```
GssapiUseS4U2Proxy
Enables the use of the s4u2Proxy Kerberos extension also known as constrained delegation This option allows an application running within Apache to operate on behalf of the user against other servers by using the provided ticket (subject to KDC authorization).
```
So why do we need both? Isn't GssapiUseS4U2Proxy enough to issue service tickets on behalf of user and use them? Also, is there is no TGT actually obtained for the client's principal, only service tickets?
3. Here I have basic understanding that Apache need somehow to talk to KDC. It does it with help of mod_auth_gssapi, which implements GSS-API interface for Apache. Apache itself does not aware of any KDC or other auth provider present, cause there is no settings in apache config about it.
So let's say apache makes some gssapi function call to initiate exchange.
- Does it start with SPNEGO negotioation, or directly "asks" for kerberos5 mechanism? (cause it is in the settings GssapiAllowedMech krb5).
We have a /etc/gss file with following settings:
[root@ipa-test conf.d]# cat /etc/gss/mech.d/gssproxy.conf
# GSS-API mechanism plugins
#
# Mechanism Name Object Identifier Shared Library Path Other Options
gssproxy_v1 2.16.840.1.113730.3.8.15.1 /usr/lib64/gssproxy/proxymech.so <interposer>
I guess by it we can confirm that gssproxy intercept all the gssapi calls on the host?
Next look at the gssproxy config for the ipa:
[root@ipa-test ~]# cat /etc/gssproxy/10-ipa.conf
#Installed and maintained by ipa update tools, please do not modify
[service/ipa-httpd]
mechs = krb5
cred_store = keytab:/var/lib/ipa/gssproxy/http.keytab
cred_store = client_keytab:/var/lib/ipa/gssproxy/http.keytab
allow_protocol_transition = true
allow_client_ccache_sync = true
cred_usage = both
euid = apache
[service/ipa-api]
mechs = krb5
cred_store = keytab:/var/lib/ipa/gssproxy/http.keytab
allow_constrained_delegation = true
allow_client_ccache_sync = true
cred_usage = initiate
euid = ipaapi
[service/ipa-sweeper]
mechs = krb5
cred_store = keytab:/var/lib/ipa/gssproxy/http.keytab
socket = /var/lib/gssproxy/ipa_ccache_sweeper.sock
euid = ipaapi
cred_usage = initiate
Let's review options for ipa-httpd and ipa-api services:
- allow_protocol_transition (This option controls whether s4u2self requests are allowed for the requesting client)
Ok, understandable, we need it in conjuction with GssapiUseS4U2Proxy on of the Apache, otherways it won't work. Though it is present for service/ipa-api and not for the service/ipa-httpd. Why so?
- allow_client_ccache_sync
This one is kind of vague for me. This option allows the proxy, in certain circumstances, to send back an additional option in the response structure of certain calls when it determines that a new ticket may have been added to the internal ccache. Clients can then replace their (encrypted) copy with the updated ccache.
So gssproxy injects option in response for a client (apache in our case?) to renew service tickets? What are the "certain calls"?
- allow_protocol_transition
So, this one is enabled only for ipa-httpd. This option controls whether s4u2self requests are allowed for the requesting client. This is shows that for some reason for ipa-httpd service we only have s4u2self allowed type of requests and for ipa-api service we have s4u2proxy. Mm, why not both?
I guess those interaction between Apache and KDC through gssproxy are the most vague in all of this.
4. Somehow user getting autheticated. But there is no TGT, is it? So how is it done?
5. What next is gssapi calls are getting intercepted by gssproxy, and when service tickets are recieved they are encrypted by it, so httpd process has no direct access to it, it can't decrypt it. This design likely aims to protect credentials in case of a successful attack on the Apache process.
6. After ldap service tickets aquired (stored in the /run/ipa/ccaches), apache access ldap on behalf of the user. Or better I say python code make ldap request to LDAP server, in GSS context that was handled by apache.
7. Getting data from LDAP
8. Perfoming http response with data from LDAP, and setting a coockie ipa_session. What is in the cookie, by the way? I thought it was TGT but now I'm not that sure
So each point highlight my areas of confusion, and I would appreciate any corrections or insights from anyone familiar with the FreeIPA client authentication process.
10 months, 1 week