Bug 485933

Summary:	Use CONFIG_SCTP_HMAC_SHA1 instead of ..._MD5
Product:	[Fedora] Fedora	Reporter:	Miloslav Trmač <mitr>
Component:	kernel	Assignee:	Neil Horman <nhorman>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	low	Docs Contact:
Priority:	low
Version:	rawhide	CC:	kernel-maint, nhorman, quintela
Target Milestone:	---
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Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	Bug Fix
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Last Closed:	2009-04-01 05:48:15 UTC	Type:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	485249

Description Miloslav Trmač 2009-02-17 15:14:23 UTC

Version-Release number of selected component (if applicable):
kernel-2.6.27.12-170.2.5.fc10.x86_64

Disclaimer: I know very little about SCTP, and I don't use it.

The cookies used for connection establishment (similar to TCP SYN cookies) use a configurable hash type.  The Fedora kernel currently uses a MD5 HMAC; MD5 is all but broken, it seems prudent to change the configuration to use a SHA-1 HMAC.

Comment 1 Neil Horman 2009-02-18 19:05:51 UTC

I think there has been some concern in the past here that using SHA1 hmacs might be a problem on some older systems that don't support that algorithm.   But its probably worth updating rawhide, if for no other reason than to see what breaks.

Comment 2 Miloslav Trmač 2009-02-18 19:14:04 UTC

As far as I understand sctp, these cookies are only used by the host that generated them, so the only possible compatibility problem could arise if the peer has buffers so small that they can not handle the additional 4 bytes.

Comment 3 Chuck Ebbert 2009-04-01 05:48:15 UTC

This has been done:

config-generic:# CONFIG_SCTP_HMAC_NONE is not set
config-generic:CONFIG_SCTP_HMAC_SHA1=y
config-generic:# CONFIG_SCTP_HMAC_MD5 is not set