922780 - NSC_DecryptUpdate should also check the input data length for block ciphers when the output buffer is provided

Status: RESOLVED FIXED

(NSS :: Libraries, defect, P2)

Description

[Wan-Teh Chang]

Attachment: Patch

NSC_DecryptUpdate checks the input data length for block ciphers when the
output buffer is not provided (|pPart| is null).  It should do the same
check when the output buffer is provided. Otherwise, it may read before
the beginning of the input data buffer and decrement ulEncryptedPartLen
to a negative number (or rather, a huge unsigned value).

Comment 1

[Ryan Sleevi]

Comment on attachment 812772 [details] [diff] [review]
Patch

Confirmed with PKCS#11 v2.20 that this is the correct error code for when the encrypted text is not a multiple of the block size, and is the highest priority error code to return.

There still needs to be a length check for the CKR_BUFFER_TOO_SMALL case, but that can be handled separately.

Comment 2

[Wan-Teh Chang]

Thanks for checking PKCS #11.  I will fix the CKR_BUFFER_TOO_SMALL problem
in bug 921687.

Patch checked in: https://hg.mozilla.org/projects/nss/rev/dec241b62016

Comment 3

[Kai Engert (:KaiE:)]

changing target milestone to 3.15.4