Bug 1463673 - radiusd silently truncates the Tunnel-password attribute in its length is over 249 characters
Summary: radiusd silently truncates the Tunnel-password attribute in its length is ove...
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: freeradius
Version: 7.4
Hardware: Unspecified
OS: Unspecified
Target Milestone: rc
: ---
Assignee: Alex Scheel
QA Contact: Filip Dvorak
Florian Delehaye
Depends On:
Blocks: 1723362
TreeView+ depends on / blocked
Reported: 2017-06-21 13:01 UTC by Patrik Kis
Modified: 2020-03-12 13:41 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Known Issue
Doc Text:
.FreeRADIUS silently truncates Tunnel-Passwords longer than 249 characters If a Tunnel-Password is longer than 249 characters, the FreeRADIUS service silently truncates it. This may lead to unexpected password incompatibilities with other systems. To work around the problem, choose a password that is 249 characters or fewer.
Clone Of:
: 1470801 1723362 (view as bug list)
Last Closed: 2019-11-22 15:04:55 UTC
Target Upstream Version:

Attachments (Terms of Use)

Description Patrik Kis 2017-06-21 13:01:09 UTC
Description of problem:
The maximum length of Tunnel-password attribute seems to the 249 characters according the specifications (the is one octet to store the value + there are some other octets used for header). If longer password is set, radiusd accepts it (do not report error and starts), but then the length is truncated to usable value.
That is not intuitive and may confuse users. If the length is over 1022 characters the radiusd simply do not start end report error. IMO, it should be the same for lengths which can not be sent over the protocol (i.e. 250 and more)

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Set up a test user with Tunnel-password (length 250 characters), eg:
testuser250 Cleartext-Password := passme
    Tunnel-Password = PjHzPhdzLzhZELZG7oD5LPW9vpkN0Q3L7n11wrsao1wmsKRrSkeGGxYiP8wJTfNjKAE4pNE1cdmdu574XmtkCHOPQBGDXeYc04iqWa6fqZVyzHaQIQKuBHFz19T2PgOGKWiV2qRtmdar9ReRH72HDvfJQPBBgXIe7ic956pOL539GpsYIdrpikaZ2UEiVZBcgblMbEp8Brmd4m9e0rFbkkAXLHfu736URPnaaL77CKc1GRgsrSV5nTVPfy

2. Run the server
3. Test with radtest:

# radtest testuser250 passme localhost 0 testing123
Sent Access-Request Id 223 from to length 92
	User-Name = "testuser250@redhat.com"
	User-Password = "passme"
	NAS-IP-Address =
	NAS-Port = 0
	Message-Authenticator = 0x00
	Cleartext-Password = "passme"
Received Access-Accept Id 223 from to length 275
	Tunnel-Password:0 = "PjHzPhdzLzhZELZG7oD5LPW9vpkN0Q3L7n11wrsao1wmsKRrSkeGGxYiP8wJTfNjKAE4pNE1cdmdu574XmtkCHOPQBGDXeYc04iqWa6fqZVyzHaQIQKuBHFz19T2PgOGKWiV2qRtmdar9ReRH72HDvfJQPBBgXIe7ic956pOL539GpsYIdrpikaZ2UEiVZBcgblMbEp8Brmd4m9e0rFbkkAXLHfu736URPnaaL77CKc1GRgsrSV5nTVPf"

^^^ Note the missing 'y' at the end of Tunnel-password attribute.

Comment 1 Alex Scheel 2019-05-02 14:37:12 UTC
Patrik / Filip,

Do either of you know if this is fixed on the RHEL 8 builds? I swear I've seen something related to this upstream, but I'm not sure if it is fixed in 3.0.17 or something newer (definitely would be in 3.0.19 **if** my memory was correct). 

IIRC, this is a limitation in the RFC.

Comment 2 Patrik Kis 2019-05-03 11:23:46 UTC
(In reply to Alex Scheel from comment #1)
> Patrik / Filip,
> Do either of you know if this is fixed on the RHEL 8 builds?

It does not seem to be the case.
My test is failing in the same way as it fails with the RHEL 7 build, for which the issue was reported
> IIRC, this is a limitation in the RFC.

I did not check the RFC, but the reported problem here is not that it does not support long passwords. The problem is that it does not detects and reports the limitation with the password length.

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