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<p>Yes, the mode suggestion sounds reasonable. I will include all of
the suggestions into the RFE for completeness sake.<br>
</p>
<p>Thanks for the feedback,</p>
<p>Valerie<br>
</p>
<div class="moz-cite-prefix">On 6/24/2020 2:58 PM, Michael StJohns
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:e8a6eb96-1739-1e47-42e7-3e32e85c6bea@comcast.net">
<div class="moz-cite-prefix">On 6/24/2020 4:58 PM, Bernd Eckenfels
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:AM6PR03MB43890588B65067E62BB98215FF950@AM6PR03MB4389.eurprd03.prod.outlook.com">
<div dir="ltr">
<div data-ogsc="">
<div dir="ltr">Hello,</div>
<div dir="ltr"><br>
</div>
<div dir="ltr">JCE implements the AESWrap cipher, but it's
does not offer the KWP mode of NIST 800-38F. KW and KWP
use the same wrapping algorithm W which is also used by
AESWrap, however do to different initialisation vectors
the existing implementation can not be used to implement
the padded wrapping.</div>
<div dir="ltr"><br>
</div>
<div dir="ltr">Is it possible to offer KWP as a special
padding mode for AESWrap or have the W mode be it's own
block mode so you can implement the padding externally?</div>
<div dir="ltr"><br>
</div>
<div dir="ltr">Gruss</div>
<div dir="ltr">Bernd</div>
<div class="ms-outlook-ios-signature"
id="ms-outlook-mobile-signature">
<div dir="ltr"><br>
</div>
<div>-- </div>
<div><a class="moz-txt-link-freetext"
href="http://bernd.eckenfels.net"
moz-do-not-send="true">http://bernd.eckenfels.net</a></div>
</div>
</div>
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</blockquote>
<p>You probably know that BouncyCastle implements KWP?</p>
<p>Reading the comments in the AESWrapCipher code, this was
created against the XML encryption standards even though the
underlying code is a straight implementation of RFC3394. <br>
</p>
<p>Rather than twiddle with this current implementation and name
mapping, it may make more sense to redo this as a normal
<Alg>/<mode>/<padding> mapping. E.g.
"AES/KeyWrap-NIST/NoPadding" or KWPPadding or AutoPadding
rather than the current "AESWrap". That would then allow for
"ChaCha20/KeyWrap-NIST/AutoPadding" and others.<br>
</p>
<p>I.e., copy the code from the current AESWrapCipher and convert
it to a mode. More work now, less later. The AutoPadding would
select the no padding if the encoded key size was a multiple of
the block length, and the KWP padding if the encoded key size
was not a multiple. Or read the IV to determine which for
unwrapping. <br>
</p>
<p>Mike</p>
<p><br>
</p>
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