radius-audit - A RADIUS authentication server audit tool
radius-audit allows to conduct configuration audits of RADIUS (RFC 2865) servers setup as authentication servers in a 802.1X environment.
More specifically, radius-audit can help auditing the TLS (RFC 5246) configuration of a RADIUS server, as well as discovering authorized EAP (RFC 3748) authentication methods. It can be used by network or system administrators to check the configuration of a RADIUS server, or by pentesters conducting a security audit.
Installation
This tool is based on Scapy. A recent version of Scapy is recommended. It can be installed as described in the official documentation.
The requirements.txt file contains the list of packages required in order to run radius-audit. Apart from Scapy, the current version of the tool only requires pyroute2. pyroute2 is used to setup network interfaces, and to benefit from the nl80211 drivers of the Linux kernel.
Note that radius-audit is compatible with both Python 2 and Python 3.
Usage
Available arguments are given in the help message (-h argument). The different types of scans that radius-audit can perform are described in the following sections.
Wired 802.1X or Wi-Fi
The iface argument is mandatory, and is used to provide the network interface that will be used to send and receive the Ethernet frames on a wired network, or to send the 802.11 frames when auditing a wireless network.
TLS configuration audit
TLS scan example
The following example shows how to start a TLS scan.
ra -iface eth0 --tls-scan
In case of error, an EAP Failure response is sent, without any hint regarding the cause of the error. For this reason, in order to make sure that a specific SSL / TLS version is not supported, one has to loop through all the available ciphersuites.
Several other options are available. For example, it is possible to start the scan from a specific TLS version (up to TLS 1.2, starting from SSLv2) using the -min-tls-version command line argument. The first SSL / TLS version for which measurements will be performed can be one of the following: sslv2, sslv3, tls10, tls11, tls12. The following example shows how to launch a scan starting from TLS 1.1:
ra -iface eth0 --tls-scan -min-tls-version tls11
TLS - Specific TLS versions and ciphersuites
The user can provide specific SSL/TLS versions and ciphersuites using the -tls-versions and -tls-ciphers options:
ra -iface eth0 -tls-versions tls10,tls11,tls12 -tls-ciphers 0x0033,0x0035,0x0039,0xc013,0xc014,0x002f,0xc030
Accepted TLS 1.0 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Accepted TLS 1.0 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Accepted TLS 1.0 TLS_RSA_WITH_AES_256_CBC_SHA
Accepted TLS 1.0 TLS_RSA_WITH_AES_128_CBC_SHA
Rejected TLS 1.0 TLS_DHE_RSA_WITH_AES_128_CBC_SHA
Rejected TLS 1.0 TLS_DHE_RSA_WITH_AES_256_CBC_SHA
Rejected TLS 1.0 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Accepted TLS 1.1 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Accepted TLS 1.1 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Accepted TLS 1.1 TLS_RSA_WITH_AES_256_CBC_SHA
Accepted TLS 1.1 TLS_RSA_WITH_AES_128_CBC_SHA
Rejected TLS 1.1 TLS_DHE_RSA_WITH_AES_128_CBC_SHA
Rejected TLS 1.1 TLS_DHE_RSA_WITH_AES_256_CBC_SHA
Rejected TLS 1.1 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Accepted TLS 1.2 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Accepted TLS 1.2 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Accepted TLS 1.2 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Accepted TLS 1.2 TLS_RSA_WITH_AES_256_CBC_SHA
Accepted TLS 1.2 TLS_RSA_WITH_AES_128_CBC_SHA
Rejected TLS 1.2 TLS_DHE_RSA_WITH_AES_128_CBC_SHA
Rejected TLS 1.2 TLS_DHE_RSA_WITH_AES_256_CBC_SHA
TLS - Test with a specific "TLS-based" EAP authentication method
By default, radius-audit will use the EAP-TLS method to perform the scan. However, it is possible to use another "TLS-based EAP" method by adding the -with-eap-method command line argument. In the following example, the EAP-TTLS authentication method will be used.
ra -iface eth0 -tls-versions tls12 -tls-ciphers 0x002f -with-eap-method ttls
Accepted TLS 1.2 TLS_RSA_WITH_AES_128_CBC_SHA
radius-audit is able to perform scans for the following "TLS-based" EAP methods:
Phase 1 authentication - Supported EAP methods enumeration
radius-audit allows to enumerate "phase 1" EAP authentication methods that are available. The following example shows how to perform such a scan using the --discover-phase-1 command line argument:
ra -iface eth0 --discover-phase-1
Accepted 4 MD5-Challenge
Rejected 5 One-Time Password (OTP)
Rejected 6 Generic Token Card (GTC)
Rejected 9 RSA Public Key Authentication
Rejected 10 DSS Unilateral
Rejected 11 KEA
Rejected 12 KEA-VALIDATE
Accepted 13 EAP-TLS
Rejected 14 Defender Token (AXENT)
Rejected 15 RSA Security SecurID EAP
Rejected 16 Arcot Systems EAP
Rejected 17 EAP-Cisco Wireless
Rejected 18 GSM Subscriber Identity Modules (EAP-SIM)
Rejected 19 SRP-SHA1
Accepted 21 EAP-TTLS
Rejected 22 Remote Access Service
Rejected 23 EAP-AKA Authentication
Rejected 24 EAP-3Com Wireless
Accepted 25 PEAP
Rejected 26 MS-EAP-Authentication
Rejected 27 Mutual Authentication w/Key Exchange (MAKE)
Rejected 28 CRYPTOCard
Rejected 29 EAP-MSCHAP-V2
Rejected 30 DynamID
Rejected 31 Rob EAP
Rejected 32 Protected One-Time Password
Rejected 33 MS-Authentication-TLV
Rejected 34 SentriNET
Rejected 35 EAP-Actiontec Wireless
Rejected 36 Cogent Systems Biometrics Authentication EAP
Rejected 37 AirFortress EAP
Rejected 38 EAP-HTTP Digest
Rejected 39 SecureSuite EAP
Rejected 40 DeviceConnect EAP
Rejected 41 EAP-SPEKE
Rejected 42 EAP-MOBAC
Accepted 43 EAP-FAST
Rejected 44 ZoneLabs EAP (ZLXEAP)
Rejected 45 EAP-Link
Rejected 46 EAP-PAX
Rejected 47 EAP-PSK
Rejected 48 EAP-SAKE
Rejected 49 EAP-IKEv2
Rejected 50 EAP-AKA
Rejected 51 EAP-GPSK
Rejected 52 EAP-pwd
Rejected 53 EAP-EKE Version 1
Rejected 54 EAP Method Type for PT-EAP
Rejected 55 TEAP
Rejected 255 Experimental
This example shows that the targeted RADIUS server seem to support several "TLS-based" EAP authentication methods: EAP-TLS, EAP-TTLS, PEAP, and EAP-FAST.
At the beginning of the authentication process, when an EAP request for a given authentication method is received, radius-audit assumes that this method is supported by the authentication server. radius-audit then tries to restart the authentication process with another method using the desired authentication type in a Legacy Nak response. This allows to speed up the enumeration process when a given authentication method is supported.
A few examples
Use a wireless interface
radius-audit can be used on a Wi-Fi network. In order to do so, the SSID must be given by the user via the-ssid command line argument.
ra -iface wlan1 -ssid demo-wpa2-eap --tls-scan
If an attempt is made to perform a scan on a Wi-Fi network which does not support 802.1X authentication (PSK), a warning message is issued:
ra -iface wlan1 -ssid demo-wpa2-psk --discover-phase-1
WARNING: (demo-wpa2-psk) AKM is not IEEE 802.1X / PMKSA caching.
Specify an identity
The -identity command line argument allows to perform the scan with a user-defined identity. When it is not provided, anonymous is used as a default value. The identity is sent in response to the EAP Identity request that begins the EAP authentication process.
ra -iface eth0 -identity johndoe --tls-scan
Output format
The --json-output command line argument can be used to print the results in JSON format:
ra -iface eth0 --tls-scan -min-tls-version tls11 --json-output
{"tls_version": "TLS 1.1", "tls_cipher_suite": "TLS_RSA_WITH_3DES_EDE_CBC_SHA", "outcome": true, "session_id": true}
{"tls_version": "TLS 1.1", "tls_cipher_suite": "TLS_NULL_WITH_NULL_NULL", "outcome": false}
{"tls_version": "TLS 1.1", "tls_cipher_suite": "TLS_RSA_WITH_NULL_MD5", "outcome": false}
{"tls_version": "TLS 1.1", "tls_cipher_suite": "TLS_RSA_WITH_NULL_SHA", "outcome": false}
[ ... ]
{"tls_version": "TLS 1.1", "tls_cipher_suite": "TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256", "outcome": false}
{"tls_version": "TLS 1.2", "tls_cipher_suite": "TLS_RSA_WITH_3DES_EDE_CBC_SHA", "outcome": true, "session_id": true}
{"tls_version": "TLS 1.2", "tls_cipher_suite": "TLS_NULL_WITH_NULL_NULL", "outcome": false}
{"tls_version": "TLS 1.2", "tls_cipher_suite": "TLS_RSA_WITH_NULL_MD5", "outcome": false}
{"tls_version": "TLS 1.2", "tls_cipher_suite": "TLS_RSA_WITH_NULL_SHA", "outcome": false}
[...]
ra -iface eth0 --discover-phase-1 --json-output
{"auth_method": 4, "auth_method_desc": "MD5-Challenge", "outcome": true}
{"auth_method": 5, "auth_method_desc": "One-Time Password (OTP)", "outcome": false}
How to speed up the scanning process ?
An administrator may be able to tune the timers available on the authenticator (switch, Wi-Fi access point) or on the server. For example, the quietPeriod timer value on the authenticators may be decreased in order to speed up the process (for more information, one can read the IEEE Std 802.1X-2004 standard). On Cisco switches, the following command, applied to an interface, allows to decrease the quietPeriod to 1 second.
sw(config-if)# dot1x timeout quiet-period 1
Acknowledgements
Thanks to Arnaud Ebalard, Nicolas Iooss, Guillaume Valadon and Philippe Valembois for their valuable input.
License
This project is licensed under the terms of the MIT license.