Problem with backslash in User-Name

[Brian Candler]

On 10/02/2017 07:28, Marco Scholl wrote:
> this idea i have, too.
>
> I have also tried
>
> radtest -t mschap "test\\radius" radius localhost 1 testing123
> radtest -t mschap 'test\\radius' radius localhost 1 testing123
> radtest -t mschap 'test\radius' radius localhost 1 testing123

Ah, there's still not enough escaping:

root at radtest:~# radtest -t mschap 'test\\radius' radius localhost 1 
testing123
Sent Access-Request Id 15 from 0.0.0.0:60124 to 127.0.0.1:1812 length 136
     User-Name = "test\radius"

By this stage, your  '\ \ r' has still become '\r' and radclient rakes 
this as CR. So it looks like there is another level of unescaping taking 
place inside radtest (which is a shell script)

So you need *four* backslashes, which you can get in single quotes like 
this:

root at radtest:~# radtest -t mschap 'test\\\\radius' radius localhost 1 
testing123
Sent Access-Request Id 201 from 0.0.0.0:36290 to 127.0.0.1:1812 length 137
     User-Name = "test\\radius"

(Without quotes, or in double-quotes, you would need 8 backslashes!)

Now you can see that radclient receives "test\\radius" which it should 
interpret as t e s t \ r a d i u s

And at last, tcpdump confirms this:

# tcpdump -i lo -nn -s0 -v -X udp port 1812
tcpdump: listening on lo, link-type EN10MB (Ethernet), capture size 
262144 bytes
11:05:05.119847 IP (tos 0x0, ttl 64, id 19098, offset 0, flags [none], 
proto UDP (17), length 165)
     127.0.0.1.53576 > 127.0.0.1.1812: RADIUS, length: 137
     Access-Request (1), id: 0x06, Authenticator: 
e03656048448efdd3e6345a719fb218f
*User-Name Attribute (1), length: 13, Value: test\radius*
       NAS-IP-Address Attribute (4), length: 6, Value: 127.0.1.1
       NAS-Port Attribute (5), length: 6, Value: 1
       Message-Authenticator Attribute (80), length: 18, Value: 
..g..){.m...%,.)
       Vendor-Specific Attribute (26), length: 16, Value: Vendor: 
Microsoft (311)
         Vendor Attribute: 11, Length: 8, Value: .......f
       Vendor-Specific Attribute (26), length: 58, Value: Vendor: 
Microsoft (311)
         Vendor Attribute: 1, Length: 50, Value: 
..........................>.=L.:z.+....c.....}..@
     0x0000:  4500 00a5 4a9a 0000 4011 31ac 7f00 0001 E...J... at .1.....
     0x0010:  7f00 0001 d148 0714 0091 fea4 0106 0089 .....H..........
     0x0020:  e036 5604 8448 efdd 3e63 45a7 19fb 218f .6V..H..>cE...!.
     0x0030:  010d *7465 7374 5c72 6164 6975 73*04 067f *..test\radius...*
     0x0040:  0001 0105 0600 0000 0150 1292 8467 0dbf .........P...g..
     0x0050:  297b bf6d 0716 8625 2c82 291a 1000 0001 ){.m...%,.).....
     0x0060:  370b 0afe 00b0 adc9 0da8 661a 3a00 0001 7.........f.:...
     0x0070:  3701 3400 0100 0000 0000 0000 0000 0000 7.4.............
     0x0080:  0000 0000 0000 0000 0000 0000 003e bc3d .............>.=
     0x0090:  4cf6 3a7a a42b 8a96 8ed0 6312 84b4 c7d9 L.:z.+....c.....
     0x00a0:  7dba 0d7f 40                             }...@

Regards,

Brian.