EAP-PEAP-MSCHAPv2

What is Expansion of EAP-PEAP-MSCHAPv2?

Protected Extensible Authentication Protocol – Microsoft Challenge Handshake Authentication Protocol version 2.

What is EAP-PEAP-MSCHAPv2?

  • An authentication method used in wireless and VPN security.

  • It encapsulates EAP inside a TLS tunnel (PEAP).

  • Uses MSCHAPv2 for inner authentication of the user’s credentials.

Why is EAP-PEAP-MSCHAPv2 useful?

  • Provides mutual authentication.

  • Protects user credentials inside an encrypted TLS tunnel.

  • Widely supported on Windows and Linux.

  • Easy to deploy without requiring client certificates.

How it works?

  • Outer TLS tunnel established between client and server (PEAP).

  • Inner authentication performed using MSCHAPv2.

  • Server validates username and password via RADIUS/AD.

  • A PMK (Pairwise Master Key) is generated for secure communication.

Where is EAP-PEAP-MSCHAPv2 used?

  • Enterprise Wi-Fi networks (802.1X).

  • VPN authentication.

  • Corporate environments integrated with Active Directory.

Which OSI layer does this protocol belong to?

  • Data Link Layer (Layer 2) as part of 802.1X authentication.

Is EAP-PEAP-MSCHAPv2 Windows specific?

  • No, but it is natively supported in Windows.

Is EAP-PEAP-MSCHAPv2 Linux specific?

  • No, but it is supported through tools like wpa_supplicant.

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

  • Uses EAP over LAN (EAPoL) for client ↔ authenticator.

  • Uses RADIUS over UDP for authenticator ↔ server.

Which Port is used by EAP-PEAP-MSCHAPv2?

  • UDP 1812 (authentication).

  • UDP 1813 (accounting).

Is EAP-PEAP-MSCHAPv2 using Client server model?

  • Yes, Client ↔ Authenticator ↔ Authentication Server (RADIUS).

Whether EAP-PEAP-MSCHAPv2 protocol uses certificates?

  • Yes, server-side certificate is mandatory to establish TLS tunnel.

  • Client certificates are optional.

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

  • Multiple EAPOL messages (Request, Response, TLS handshake packets).

  • Typically 8–12 messages depending on negotiation.

Whether EAP-PEAP-MSCHAPv2 Protocol uses client certificates?

  • Usually No (not required).

Whether EAP-PEAP-MSCHAPv2 Protocol uses Server Certificates?

  • Yes, mandatory for TLS tunnel establishment.

Is EAP-PEAP-MSCHAPv2 Protocol dependent on TCP?

  • No, it relies on EAPoL and UDP (RADIUS).

Is EAP-PEAP-MSCHAPv2 Protocol dependent on UDP?

  • Yes, for RADIUS communication.

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

  • Supplicant (Client device)

  • Authenticator (AP or Switch)

  • Authentication Server (RADIUS/AD)

Does EAP-PEAP-MSCHAPv2 Protocol work with FreeRADIUS server on Linux?

  • Yes, fully supported.

Does EAP-PEAP-MSCHAPv2 Protocol work with internal RADIUS server of hostapd?

  • Yes, with proper configuration.

What is the RFC version used for EAP-PEAP-MSCHAPv2 Protocol?

  • PEAP is defined in RFC 4851 (experimental).

  • MSCHAPv2 details are from Microsoft documentation (not RFC-standardized).

During Connection Procedure which EAPoL Packets are encrypted?

  • Packets inside the PEAP tunnel (inner authentication messages).

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

  • Stage 1: EAPOL Start and Identity exchange.

  • Stage 2: TLS tunnel setup using server certificate.

  • Stage 3: MSCHAPv2 challenge/response inside TLS tunnel.

  • Stage 4: Server validates credentials via RADIUS/AD.

  • Stage 5: PMK generated and shared with authenticator.

  • Stage 6: 4-way handshake to derive session keys.

What is the final output of Connection Procedure?

  • PMK and PTK (session keys) established for secure communication.

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

  • 256-bit Pairwise Master Key (PMK).

Where is the use of PMK generated by the Connection Procedure?

  • Used in the 4-way WPA2 handshake to derive session encryption keys (PTK).

  • 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=peap

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=PEAP
phase2="auth=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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