Hi Thomas, thanks for the feedback
1. Were there guidelines? Not really, though I looked at other
parameter definitions in com.sun.crypto.provider and tried to follow
along the same lines that they do. One thing that should be changed
is the LINE_SEP assignment shouldn't be an explicit getProperty
call. I noticed most are doing System.lineSeparator() so I'll
change my implementation to match that. None of these params appear
to stringify as json, so I'll probably keep things consistent with
the other parameter output.
2. You make a fair point with respect to a null SecureRandom. I can
make that spec change.
3. Let me think on this one - I shied away from ChaCha20ParameterSpec
for AEAD mode only because you have this nonce field that is set but
gets ignored. But making ChaCha20ParameterSpec an IvParameterSpec
potentially runs into the same issue were it used for a
ChaCha20-Poly1305 cipher. If I had to choose between the two I
think I'd go with allowing ChaCha20ParameterSpec to be used with
CC20-P1305 rather than making it a subclass of IvParameterSpec.
Doing the former helps from a type safety perspective that you
couldn't use a ChaCha20ParameterSpec with other Ciphers that require
an IvParameterSpec. I know I had some discussions early on in the
design where we talked about this, I need to refresh my memory as to
why we didn't allow it.
--Jamil
On 3/26/2018 12:45 PM, Thomas Lußnig wrote:
Hi Jamil,
1) where there any guidelines about how the engineToString should be
formatted ?
I ask because i wondering why we need two new lines with access to the
System property.
If it is represented as single line json no need to line break would
be needed.
Gruß Thomas
/** * Creates a formatted string describing the parameters. * *
@return a string representation of the ChaCha20 parameters. */
@Override protected String engineToString() { String LINE_SEP =
System.getProperty("line.separator"); HexDumpEncoder encoder = new
HexDumpEncoder(); StringBuilder sb = new StringBuilder(LINE_SEP +
"nonce:" + LINE_SEP + "[" + encoder.encodeBuffer(nonce) + "]"); return
sb.toString(); }
2) I do not think it is an good idea to say no secureRandom=null will cause IV
to be null.
I see here the risk of weak implementations. I would suggest to throw an
Exception to
enforce secure usages. If someone really want an insecure IV he can provide
am SecureRandom
implementation retuning 0 only or an matching IV.
* @param random a {@code SecureRandom} implementation. If {@code null}
* is used for the random object, then a nonce consisting of all
* zero bytes will be used. Otherwise a random nonce will be
* used.
3) If ChaCha20ParameterSpec would extends IvParameterSpec if would be valid for
booth modes in engineInit.
Even if the counter is not needed.
As an alternative i would allow ChaCha20ParameterSpec also for AEAD mode.
Grup Thomas
On 3/26/2018 9:08 PM, Jamil Nimeh wrote:
Hello all,
This is a request for review for the ChaCha20 and ChaCha20-Poly1305
cipher implementations. Links to the webrev and the JEP which
outlines the characteristics and behavior of the ciphers are listed
below.
http://cr.openjdk.java.net/~jnimeh/reviews/8153028/webrev.01/
http://openjdk.java.net/jeps/329
Thanks,
--Jamil
