EAP-TTLS-EAP-MSCHAPv2

What is Expansion of EAP-TTLS-EAP-MSCHAPv2?

Extensible Authentication Protocol - Tunneled Transport Layer Security - Extensible Authentication Protocol - Microsoft Challenge Handshake Authentication Protocol version 2.

What is EAP-TTLS-EAP-MSCHAPv2?

EAP-TTLS-EAP-MSCHAPv2 is an authentication method that establishes a secure TLS tunnel using EAP-TTLS, inside which the MSCHAPv2 challenge-response authentication protocol is performed to verify user credentials securely.

Why is EAP-TTLS-EAP-MSCHAPv2 useful?

  • Protects user credentials by tunneling MSCHAPv2 inside a TLS encrypted channel.

  • Supports password-based authentication with strong encryption.

  • Compatible with many legacy systems and widely supported by clients and servers.

  • Does not require client certificates, easing deployment.

How it works?

  1. TLS tunnel is established between client and server using EAP-TTLS.

  2. Inside the encrypted tunnel, MSCHAPv2 challenge is sent by the server.

  3. Client responds with hashed credentials using MSCHAPv2.

  4. Server validates response and authenticates client.

  5. Session keys are derived for secure communication.

Where is EAP-TTLS-EAP-MSCHAPv2 used?

  • Enterprise Wi-Fi (WPA/WPA2-Enterprise) authentication.

  • VPN authentication requiring password-based security.

  • Networks needing secure tunneled authentication without client certificates.

Which OSI layer does this protocol belong to?

  • Application Layer (Layer 7).

IS EAP-TTLS-EAP-MSCHAPv2 windows specific?

  • No, supported across multiple platforms including Windows.

IS EAP-TTLS-EAP-MSCHAPv2 Linux Specific?

  • No, supported by Linux supplicants like wpa_supplicant.

Which Transport Protocol is used by EAP-TTLS-EAP-MSCHAPv2?

  • EAPOL for client-authenticator communication.

  • RADIUS over UDP between authenticator and authentication server.

Which Port is used by EAP-TTLS-EAP-MSCHAPv2?

  • UDP port 1812 (RADIUS Authentication).

Is EAP-TTLS-EAP-MSCHAPv2 using Client server model?

  • Yes, involves supplicant (client), authenticator (AP), and authentication server.

Whether EAP-TTLS-EAP-MSCHAPv2 protocol uses certificates?

  • Requires server certificates to establish TLS tunnel.

  • Client certificates generally not required.

How many frame exchanges are seen during connection for EAP-TTLS-EAP-MSCHAPv2 protocol?

  • Several EAPOL frames during TLS handshake and inner MSCHAPv2 exchange; typically dozens of frames total.

Whether EAP-TTLS-EAP-MSCHAPv2 Protocol uses client certificates?

  • No, authentication uses MSCHAPv2 inside TLS tunnel instead.

Whether EAP-TTLS-EAP-MSCHAPv2 Protocol uses Server Certificates?

  • Yes, required for TLS tunnel establishment.

IS EAP-TTLS-EAP-MSCHAPv2 Protocol depends on TCP?

  • Not directly; EAP/EAPOL works over Layer 2.

  • TLS handshake inside EAP-TTLS runs over EAPOL frames.

  • RADIUS uses UDP.

IS EAP-TTLS-EAP-MSCHAPv2 Protocol depends on UDP?

  • Yes, RADIUS uses UDP.

What are the roles involved when testing EAP-TTLS-EAP-MSCHAPv2 Protocol?

  • Client/Supplicant.

  • Authenticator (Access Point).

  • Authentication Server (e.g., FreeRADIUS).

  • Packet capture and analysis tools.

Does EAP-TTLS-EAP-MSCHAPv2 Protocol work with free radius server on Linux?

  • Yes, FreeRADIUS fully supports this method.

Does EAP-TTLS-EAP-MSCHAPv2 Protocol work with Internal radius server of hostapd?

  • Internal RADIUS server has limited support; external RADIUS preferred.

What is the RFC version use for EAP-TTLS-EAP-MSCHAPv2 Protocol?

  • EAP-TTLS: RFC 5281.

  • MSCHAPv2: Defined in Microsoft RFCs (draft references, not standardized by IETF).

During Connection Procedure which EPoL Packets are encrypted?

  • Inner EAP-MSCHAPv2 messages are encrypted inside TLS tunnel.

  • TLS handshake messages initially unencrypted, then tunnel is established.

Can you Explain different stages of Connection Procedure for EAP-TTLS-EAP-MSCHAPv2 Protocol?

  1. TLS handshake establishes secure tunnel between client and server.

  2. Server sends MSCHAPv2 challenge inside tunnel.

  3. Client responds with MSCHAPv2 response.

  4. Server verifies and authenticates client.

  5. PMK derived and used for securing data link.

What is the final output of Connection Procedure?

  • Authentication success or failure.

  • Generation of PMK (Pairwise Master Key).

  • Secure network access on success.

What is the format of the key generate after the connection procedure?

  • 256-bit Pairwise Master Key (PMK).

Where the use of PMK generated by the Connection Procedure?

  • Used in 4-way handshake to derive temporal encryption keys.

  • Secures data transmission between client and access point.

  • In this section, you are going to learn

  • Terminology

  • Version Info

  • rfc details

  • Run Free RADIUS

FreeRADIUS: Download latest freeradius source code

Note

  • Make sure internet is available in laptop to download freeradius package

test:~$ wget https://github.com/FreeRADIUS/freeradius-server/archive/v3.0.x.tar.gz

FreeRADIUS: Extract freeradius

test:~$ tar -zvf v3.0.x.tar.gz

FreeRADIUS: Change directory to Radius server

test:~$ cd freeradius-server-3.0/

FreeRADIUS: Check the current working directory using pwd command

Note

  • Make sure your current working directory is freeradius-server-3.0

test:~$ pwd
/home/test/freeradius-server-3.0

FreeRADIUS: Open debian/rules and add this line –without-rml_sql_iodbc above –without-rlm_eap_ikev2

test:~$ vim debian/rules
--without-rml_sql_iodbc \
--without-rlm_eap_ikev2 \

FreeRADIUS: Configure for Compilation

test:~$ ./configure

FreeRADIUS: Build the Radius server

test:~$ make

FreeRADIUS: Go to raddb folder (all radius server/client files and certificates and keys will be generated here)

test:~$ cd /usr/local/etc/raddb

FreeRADIUS: Open clients.conf file and verify localhost client is present else add your own client like below

test:~$ sudo vi clients.conf

client 192.168.56.10{
ipaddr = 192.168.56.10
secret = testing123
}  

FreeRADIUS: Open users file and uncomment below two lines or add

test:~$ sudo vi users

bob 	Cleartext-Password := "testing123"
 	Reply-Message := "Hello, %{User-Name}"

FreeRADIUS: Set default_eap_type=tls in eap file located in /usr/local/etc/raddb/mods-enabled

test:~$ sudo vi /usr/local/etc/raddb/mods-enabled/eap

default_eap_type=ttls

FreeRADIUS: Start radius server

test:~$ sudo radiusd -X
  • Run AP mode operation with hostapd

AP : Download hostapd

Note

  • Make sure internet is available in laptop to download hostapd package

test:~$ wget http://w1.fi/releases/hostapd-2.9.tar.gz

AP: Install required packages

test:~$ sudo apt install libnl-genl-3-dev libnl-3-dev libdbus-glib-1-dev

AP : Extract hostapd

test:~$ tar -xzvf hostapd-2.9.tar.gz

AP : Change directory to hostapd

test:~$ cd hostapd-2.9/hostapd/

AP : Check the current working directory using pwd command

Note

  • Make sure your current working directory is hostapd

test:~$ pwd
/home/test/hostapd-2.9/hostapd

AP : Copy the contents of defconfig file to .config file

Note

  • .config file is required for make to start compilation of hostapd

test:~$ sudo cp defconfig .config

AP : Complile hostapd

Note

  • Compile hostapd by running make command

test:~$ make

AP : Check for the binaries created

Note

  • Make sure hostapd and hostapd_cli are present

test:~$ ls
hostapd
hostapd_cli

AP : Create a hostapd.conf file in /etc/hostapd folder with below content

test:~$ sudo vim /etc/hostapd/hostapd.conf

ctrl_interface=/var/run/hostapd
interface=enp0s8
driver=wired
logger_stdout=1
logger_stdout_level=1
debug=2
ieee8021x=1
eap_server=0
eap_user_file=/etc/hostapd/eap_user
eap_reauth_period=3600
use_pae_group_addr=1
auth_algs=1
auth_server_addr=127.0.0.1
auth_server_port=1812
auth_server_shared_secret=testing123
acct_server_addr=127.0.0.1
acct_server_port=1812
acct_server_shared_secret=testing123
macaddr_acl=0
ca_cert=/usr/local/etc/raddb/certs/ca.pem
server_cert=/usr/local/etc/raddb/certs/server.crt
private_key=/usr/local/etc/raddb/certs/server.p12
private_key_passwd=whatever 

AP : Create a file eap_user in /etc/hostapd/ folder with below content

test:~$ sudo vim /etc/hostapd/eap_user

AP : Run hostapd

test:~$ sudo ./hostapd /etc/hostapd/hostapd.conf
enp0s8: interface state UNINITIALIZED->ENABLED
enp0s8: AP-ENABLED

STA : Download wpa_supplicant

Note

  • Make sure internet is available in laptop to download supplicant package

test:~$ wget https://w1.fi/releases/wpa_supplicant-2.9.tar.gz

STA: Install required packages

test:~$ sudo apt install libnl-genl-3-dev libnl-3-dev libdbus-glib-1-dev

STA : Extract wpa_supplicant

test:~$ tar -xvf wpa_supplicant-2.9.tar.gz

STA : Change directory to wpa_supplicant

test:~$ cd wpa_supplicant-2.9/wpa_supplicant/

STA : Check the current working directory using pwd command

Note

  • Make sure your current working directory is wpa_supplicant

test:~$ pwd
/home/test/wpa_supplicant-2.9/wpa_supplicant

STA : Copy the contents of defconfig file to .config file

Note

  • .config file is required for make to start compilation of supplicant

test:~$ cp defconfig .config

STA : Compile wpa_supplicant

Note

  • Compile supplicant by running make command.

test:~$ make

STA: You might get errors while make regarding openssl headers in that case install the openssl headers and then do make clean and then do make again.

test:~$ sudo apt install libssl-dev
test:~$ make clean
test:~$ make

STA : Check for the binaries created

Note

  • Make sure wpa_supplicant and wpa_cli are present

test:~$ ls
wpa_supplicant
wpa_cli

STA: Copy required certificates from hostapd to wpa_supplicant

STA : Create wpa_supplicant.conf

test:~$ sudo vim wpa_supplicant.conf

ctrl_interface=/run/wpa_supplicant
update_config=1
network={
key_mgmt=WPA-EAP
eap=TTLS
phase2="autheap=MSCHAPV2"
identity="bob"
password="testing123"
}

STA : Run wpa_supplicant

test:~$ sudo ./wpa_supplicant -D wired -i enp0s8 -c wpa_supplicant.conf
enp0s8: CTRL-EVENT-EAP-SUCCESS EAP authentication completed successfully

STA: Test

test:sudo ./wpa_cli -i enp0s8
> status
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