CODEWITHSUNDEEP
phpencryptionradiusfreeradius
Ahmed Bermawy
Ahmed Bermawy

Reputation: 2530

CHAP Password decrypt - Freeradius

I'm using Freeradius to authenticate user from my server using php code 

update control {
    Reply-Message := `/usr/bin/php -f /etc/raddb/auth.php '%{User-Name}' '%{CHAP-Password}' '%{CHAP-Challenge}' auth`
}

it return CHAP-Password = 0xa2a421bf267fbffabe5696cf1c6d54f479

and the CHAP-password is Hashing, but i don't have clear text password in database, the password is hashed .

It is working fine with PAP Protocol, but i need to use CHAP for other server configuration

So my question: is there anyway to decrypt the CHAP-Password , or if this is not possible to tell CHAP not to hashing the password in configuration

Upvotes: 0

Views: 11285

Answers (2)

Ahmed Bermawy
Ahmed Bermawy

Reputation: 2530

After searching for many and many hours I finally make chap authenticate with my database:

First: I'm working on freeradius 3, because there are many changes form radius 2 and radius 3

Second: Database Configuration

I'm using mysql with 2 Databases like this:

  1. members

    • users
      • id
      • username
      • password
      • .......
      • .......
    • ........

  2. radius

    • radcheck
      • id
      • username
      • attribute
      • op
      • value
    • radpostauth
    • ......

You need to configure sql file in this root

sudo nano mods-available/sql

And change this values

driver = "rlm_sql_mysql"
dialect = "mysql"
server = "localhost"
login = "your_database_username"
password = "your_database_password"

Then save and restart the radius by:

sudo service radiusd restart

If radius restart without error, so the configuration is correct

After restarting radius you need to copy this file to mods-enabled

so radius run this configuration, because all files in mods-enabled is what radius running it

sudo cp mods-available/sql mods-enabled/sql

To check if everything running OK

sudo radiusd -XC

This command run debug on radius, and return errors .

if the end of this debug is

Configuration appears to be OK

so everything is fine until now

Third: Database Connection and Authenticate

Now we need to authenticate the username via CHAP , so we need to write query to select the username from user table

This query will be in this file queries.conf in this root

sudo nano mods-config/sql/main/mysql/queries.conf

And change the authorize_check_query to

authorize_check_query = "\
    SELECT members.user.id as id, \
    members.user.username as username, \
    'Cleartext-Password' as attribute, \
    members.user.password as value, \
    ':=' as op \
FROM members.user \
WHERE members.user.username = '%{SQL-User-Name}' \
ORDER BY members.user.id"

FYI , the password must be in plain text, because as you see the attribute is Cleartext-Password

Now let's add in table user row with username = "ahmed" and password = "test"

and try to test authentication

radtest -t chap ahmed test localhost 1812 testing123

if you receive

Received Access-Accept Id 105 from 127.0.0.1:1812 to 127.0.0.1:38259 length 20

So you are Done,

also i want to thanks @MatthewNewton for his answer and comments on my question :D

Upvotes: 1

Matthew Newton
Matthew Newton

Reputation: 655

CHAP is challenge-response. The hex you see is not an encrypted password and there is no way to "decrypt" it to get a plain-text password.

With PAP you can have an encrypted password on the server, or plaintext. You are sent a plaintext password which you can test.

With CHAP you need the plaintext password on the server to check that the response to the challenge is correct.

So you can't do what you want to do in the current form.

Upvotes: 1

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