Bug 1039311 - dropbearkey should create at least 3072 bit RSA keys
Summary: dropbearkey should create at least 3072 bit RSA keys
Keywords:
Status: MODIFIED
Alias: None
Product: Fedora
Classification: Fedora
Component: dropbear
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
low
Target Milestone: ---
Assignee: Christopher Meng
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2013-12-07 20:55 UTC by Till Maas
Modified: 2018-04-06 15:47 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: Enhancement
Doc Text:
Clone Of:
Environment:
Last Closed:
Type: Bug


Attachments (Terms of Use)

Description Till Maas 2013-12-07 20:55:35 UTC
Description of problem:
The European Union Agency for Network and Information Security recommends to use at least RSA 3072: http://www.enisa.europa.eu/activities/identity-and-trust/library/deliverables/algorithms-key-sizes-and-parameters-report

dropbearkey in F19 and EPEL6 creates RSA 1024 keys by default.


Version-Release number of selected component (if applicable):
dropbear-2013.59-1.fc19
dropbear-2013.59-1.el6

How reproducible:
always

Steps to Reproduce:
1.dropbearkey -t rsa -f dropbear_rsa_host_key

Actual results:
Will output 1024 bit rsa secret key to 'dropbear_rsa_host_key'

Expected results:
Should be 3072 bit

Additional info:
Please fix this both in EPEL and Fedora

Comment 1 Christopher Meng 2013-12-11 06:59:52 UTC
1. I've already came up with a idea that generating keys in %post section.

It's controllable for the key length but I'm not sure if users will accept this change.

2. I think this should be fixed in upstream but not here.

3. What about the states in the US?

Comment 2 Till Maas 2013-12-21 08:35:24 UTC
(In reply to Christopher Meng from comment #1)
> 1. I've already came up with a idea that generating keys in %post section.

Creating keys during %post might lead to problems because of missing entropy. 

> 2. I think this should be fixed in upstream but not here.

Regardless of whether upstream thinks this is a good idea, it should be changed in Fedora. However, it is a good idea to forward this information to them.
For example it does not make sense to use different default key sizes in dropbear-keygen and ssh-keygen.

> 3. What about the states in the US?

The NIST allows RSA 2048 keys:
http://csrc.nist.gov/publications/nistpubs/800-57/sp800-57_part1_rev3_general.pdf

Therefore RSA 3072 keys would be allowed by the NIST as well. However, since several packages seem to be affected, I am going to get a packaging guideline for this.

Comment 3 Christopher Meng 2013-12-22 00:59:26 UTC
I've seen your post at security list, I will follow up.

Comment 4 Fedora Update System 2018-04-06 15:47:02 UTC
dropbear-2018.76-1.fc28 has been submitted as an update to Fedora 28. https://bodhi.fedoraproject.org/updates/FEDORA-2018-ff2964dadb


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