Bug 20679 - AES keys should not be tied to CTR or CBC
Summary: AES keys should not be tied to CTR or CBC
Alias: None
Product: Web Cryptography
Classification: Unclassified
Component: Web Cryptography API Document (show other bugs)
Version: unspecified
Hardware: PC All
: P2 normal
Target Milestone: ---
Assignee: David Dahl
QA Contact:
Depends on:
Reported: 2013-01-15 20:32 UTC by Mark Watson
Modified: 2013-01-21 16:14 UTC (History)
1 user (show)

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Description Mark Watson 2013-01-15 20:32:48 UTC
Presently, the API allows import or generation of AES keys using the "AES-CTR" or "AES-CBC" algorithms. However the AES mode is not really a property of the key.

Consider removing the generateKey operation from AES-CTR and AES-CBC and defining a new algorithm, "AES", supporting generateKey, importKey and exportKey.
Comment 1 Ryan Sleevi 2013-01-21 16:14:13 UTC
This is a design choice, not a defect.

The re-use of an AES key in multiple modes of operation can be fatal to the underlying security guarantees. A key used to protect or unprotect data with a particular algorithm should not be reused for any other algorithms. See also the discussion of Key Tainting.