RFR: ChaCha20 and ChaCha20/Poly1305 Cipher implementations
Sean Mullan
sean.mullan at oracle.com
Tue May 8 17:49:48 UTC 2018
- ChaCha20ParameterSpec.java
The methods don't need to be final now that the class is final.
- ChaCha20Poly1305Parameters.java
122 if (decodingMethod.equalsIgnoreCase(DEFAULT_FMT)) {
123 engineInit(encoded);
The spec for engineInit() says if decodingMethod is null, the default
encoding should be used, so the code above should be:
122 if (decodingMethod == null ||
decodingMethod.equalsIgnoreCase(DEFAULT_FMT)) {
123 engineInit(encoded);
Looks good otherwise.
--Sean
On 5/4/18 10:06 AM, Jamil Nimeh wrote:
> Round 5.
>
> This adds Sean's comments. Sean, I was never able to execute a case on
> init where a half-baked object would fail. In most cases it would fail
> in checks in javax.crypto.Cipher before it ever made it down to my
> code. I'm pretty confident the init sequence is OK. I did move the
> setting of a few data members toward the end of the init sequence but
> setting the key and nonce is necessary before creating the initial
> state, which is then used for generating an authentication key for AEAD
> mode and generating keystream.
>
> http://cr.openjdk.java.net/~jnimeh/reviews/8153028/webrev.05
>
> Also the CSR has been finalized and can be found here:
> https://bugs.openjdk.java.net/browse/JDK-8198925
>
> --Jamil
>
> On 04/27/2018 02:21 PM, Jamil Nimeh wrote:
>>
>> Round 4 of updates for ChaCha20 and ChaCha20-Poly1305, minor stuff mostly:
>>
>> * Added words in the description of javax.crypto.Cipher recommending
>> callers reinitialize the Cipher to use different nonces after each
>> complete encryption or decryption (similar language to what exists
>> already for AES-GCM encryption).
>> * Added an additional test case for ChaCha20NoReuse
>> * Made accessor methods for ChaCha20ParameterSpec final and cleaned
>> up the code a bit based on comments from the field.
>>
>> http://cr.openjdk.java.net/~jnimeh/reviews/8153028/webrev.04/
>>
>> Thanks!
>>
>> --Jamil
>>
>>
>> On 04/13/2018 11:59 AM, Jamil Nimeh wrote:
>>> Round 3 of updates for ChaCha20 and ChaCha20-Poly1305:
>>>
>>> * Removed the key field in ChaCha20 and Poly1305 implementations and
>>> only retain the key bytes as an object field (thanks Thomas for
>>> catching this)
>>>
>>> * Added additional protections against key/nonce reuse. This is a
>>> behavioral change to ChaCha20 and ChaCha20-Poly1305. Instances of
>>> these ciphers will no longer allow you to do subsequent
>>> doUpdate/doFinal calls after the first doFinal without
>>> re-initializing the cipher with either a new key or nonce. Attempting
>>> to reuse the cipher without a new initialization will throw an
>>> IllegalStateException. This is similar to the behavior of AES-GCM in
>>> encrypt mode, but for ChaCha20 it needs to be done for both encrypt
>>> and decrypt.
>>>
>>> http://cr.openjdk.java.net/~jnimeh/reviews/8153028/webrev.03/
>>>
>>> Thanks,
>>> --Jamil
>>>
>>> On 04/10/2018 03:34 PM, Jamil Nimeh wrote:
>>>> Hello everyone,
>>>>
>>>> This is a quick update to the previous webrev:
>>>>
>>>> * When using the form of engineInit that does only takes op, key and
>>>> random, the nonce will always be random even if the random parameter
>>>> is null. A default instance of SecureRandom will be used to create
>>>> the nonce in this case, instead of all zeroes.
>>>>
>>>> * Unused debug code was removed from the ChaCha20Cipher.java file
>>>>
>>>> * ChaCha20Parameters.engineToString no longer obtains the line
>>>> separator from a System property directly. It calls
>>>> System.lineSeparator() similar to how other AlgorithmParameter
>>>> classes in com.sun.crypto.provider do it.
>>>>
>>>> http://cr.openjdk.java.net/~jnimeh/reviews/8153028/webrev.02/
>>>>
>>>> Thanks,
>>>>
>>>> --Jamil
>>>>
>>>>
>>>> On 03/26/2018 12:08 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
>>>>
>>>
>>
>
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