2FA - Active Directory ntlm_auth and yubikey

28 Jul 2021

      Hi,

I have been scouring the Internet for a few days now looking for
information about
setting up 2 FA with AD (ntlm_auth) and Yubikey

I found this , which was very useful but it seems to rely on adding the
yubikey to the AD account .
I was hoping to be able to do it without making changes to the AD accounts
Is this possible ?

http://lists.freeradius.org/pipermail/freeradius-users/2021-February/099521....

Basically, the workflow that I am looking for is

     1. configure Apache website with AddRadiusAuth pointing to radius
server (DONE)
      2. configure freeradius ntlm_auth ( by leveraging samba/winbind)
(DONE)
           I was able to connect to the website using my AD credentials
     3. configure self-hosted yubico server to validate yubikeys (DONE)
          tested
      3. install and configure freeradius yubikey
          This I am not sure how to test
     4. configure freeradius to authenticate via ntlm_auth and, if
successful, via yubikey
           This where I am stuck

Here are some details

10.10.30.111 - Yubikey validation server
10.10.30.112 -  where Apache website is hosted
10.10.30.114 -  FreeRADIUS Version 3.0.16

"..
ntlm_auth: Program executed successfully
(0)     [ntlm_auth] = ok
(0)     if (ok) {
(0)     if (ok)  -> TRUE
(0)     if (ok)  {
(0)       update reply {
(0)         EXPAND %{randstr:aaaaaaaaaaaaaaaa}
(0)            --> t6cJ6I2cWiGii1aG
(0)         State := 0x7436634a364932635769476969316147
(0)         Reply-Message := "Please enter OTP"
(0)       } # update reply = noop
(0)       policy challenge {
(0)         update control {
(0)           &Response-Packet-Type = Access-Challenge
(0)         } # update control = noop
(0)         [handled] = handled
(0)       } # policy challenge = handled
(0)     } # if (ok)  = handled
(0)   } # Auth-Type ntlm_auth = handled
(0) Using Post-Auth-Type Challenge
(0) # Executing group from file /etc/freeradius/3.0/sites-enabled/default
(0)   Challenge { ... } # empty sub-section is ignored
(0) Sent Access-Challenge Id 105 from 10.10.30.114:1812 to 10.10.30.112:1026
length 0
(0)   State := 0x7436634a364932635769476969316147
(0)   Reply-Message := "Please enter OTP"
(0) Finished request
Waking up in 4.9 seconds.
.."

sites-enabled excerpt

 if (!control:Auth-Type) {
          update control {
             Auth-Type = "ntlm_auth"
          }
         }
}
authenticate {
         Auth-Type ntlm_auth {
                ntlm_auth
                if (ok) {
                        update reply {
                                State := "%{randstr:aaaaaaaaaaaaaaaa}"
                                Reply-Message := "Please enter OTP"
                        }
                        challenge
         }
}
        Auth-Type PAP {
                pap
        }
        Auth-Type CHAP {
                chap
        }
        Auth-Type MS-CHAP {
                mschap
        }
        mschap
        digest
        ntlm_auth
        yubikey
        eap
..."

/mods-enabled/yubikey
"...
yubikey {
        id_length = 12
        split = yes
        decrypt = no
        validate = yes
        validation {
                servers {
                        uri = '
http://10.10.30.111/wsapi/2.0/verify?id=%d&otp=%s'
                }
                client_id = 1
                api_key = 'my_key'
                pool {
                        start = ${thread[pool].start_servers}
                        min = ${thread[pool].min_spare_servers}
                        max = ${thread[pool].max_servers}
                        uses = 0
                        retry_delay = 30
                        lifetime = 0
                        idle_timeout = 60
                        spread = yes
                }
        }
}
..."

Any guidance / help will be greatly appreciated
Also, if there is a better scalable/ enterprise ready way to configure
freeradius 2FA with AD and  Yubikey I'll be happy to look into it

Many thanks
Steven

2FA - Active Directory ntlm_auth and yubikey

Steven Vacaroaia