[Cryptography Team] [Vm-dev] Smalltalk code calling SHA2Plugin
Robert Withers
robert.withers at pm.me
Wed Jul 22 17:47:21 UTC 2020
Hi Levente,
I must admit, after reflection, that I LIKE that SHA256 new may return a different class. Essentially, the #new method of SHA256, in this scenario, will be the factory method, instad of HshFunction newSHA256. This factory method may return a pluginized SHA256 concrete subclass or itself as default. The reason I like this is that we would reference the "abstract" class specific to the hash algorithm as SHA256, exactly the same lexeme.
In our current case, the SHA256 is also a concrete class, the default when no plugins around. If this duality of SHA256 being both abstract and concrete, is an issue, we could copy SHA256 to SHA256InImage and then have a proper strict abstract class. This is my feeling that opposite of creating confusion it specifies the Lexeme of this hashFunction and so clarifies.
Newbie: "How do I use SHA256?"
Wise Council: "Code it as SHA256 new. Then send hashStream: to it.".
Jester: "Watch out it is tricky picky. It may return an instance of a DIFFERENT concrete class....correctly so.
my 2 pennies,
Kindly,
rabbit
On 7/21/20 9:56 PM, Levente Uzonyi wrote:
> Hi Robert,
>
> On Tue, 21 Jul 2020, Robert wrote:
>
>> Hub Levente,
>>
>> I like the idea of SHA256 and friends to throw an exception when #new is called directly
>> SHA256 new.
>> With a message to call newSHA256.
>>
>> What do you think?
>
> I think #new should return an instance of the receiver. That's what
> everyone expects when #new is sent to a class, isn't it?
> And if #new raised an error, what would #newSHA256 send to create an
> instance? #basicNew + #initialize? I don't like that.
>
> Levente
>
>> Kindly,
>> Robert
>>
>> On Tue, Jul 21, 2020 at 14:02, Levente Uzonyi
>> [<leves at caesar.elte.hu>](mailto:leves at caesar.elte.hu)
>> wrote:
>> Hi Chris,
>>
>> On Mon, 20 Jul 2020, Chris Muller wrote:
>>
>> > Hi Levente,
>> >
>> > > > HashFunction newSHA256
>> > > >
>> > > > instead of
>> > > >
>> > > > SHA256 new
>> > > >
>> > > > in order to take advantage of Levente's plugin.
>> > >
>> > > That is indeed some sort of a change but it only affects those who
>> > > compiled the SHA256Plugin themselves since that plugin wasn't shipped with
>> > > the VM.
>> >
>> > Ah, you're speaking about legacy code. I really hope we can include your plugin in future VM's. Are Eliot, et al, on board?
>>
>> The most recent VMs ship with the plugins.
>>
>> > > I decided against the practice of making #new return an instance of
>> > > another class than the receiver, as it was with the previous
>> > > implementation, because that makes it a lot harder for others to
>> > > understand the code.
>> >
>> > Hm. I sort of agree, although I guess Factory is a recognized pattern. To me, the issue is that writing
>> >
>> > "SHA256 new"
>> >
>> > , is a perfectly intuitive and obvious way to use it, but sticking out like a sore thumb as a subversively-wrong-way to-use-it. It'd be better if it threw an error, and even better than that if it just worked.
>> >
>> > I know you care about the quantity of methods in the image (as do I), how about quality? Can SHA256 #new be improved by doing essentially what HashFunction #newSHA256 does, and simply sending some alternative
>> to new (i.e.,
>>
>> It's not clear what do you mean by caring about the quantity of methods.
>>
>> > basicNew initialize) to avoid the recursion?
>>
>> That would do exactly what I do not want to do: #new would return an
>> object whose class is not SHA256.
>>
>> >
>> > Above, you mentioned you decided against the practice, does that mean you're writing:
>> >
>> > SHA256 newSHA256
>> >
>> > ? If not, how did you do it?
>>
>> Use HashFunction's class side #new* methods to create the instances.
>> HashFunction is a facade and a factory at the same time.
>> I originally wanted to create a separate class for this role named Hasher,
>> but HashFunction seemed to work just as well.
>>
>> Levente
>>
>> >
>> > Thanks again for this great work.
>> >
>> > - Chris
>> >
>> >
>> > On Sun, Jul 19, 2020 at 9:55 PM Levente Uzonyi
>> [<leves at caesar.elte.hu>](mailto:leves at caesar.elte.hu)
>> wrote:
>> > Hi Chris,
>> >
>> > On Sun, 19 Jul 2020, Chris Muller wrote:
>> >
>> > > Hi Robert and Levente,
>> > >
>> > > Yes, I *think* so! I'm just now getting up to speed after reading
>> > > that epic thread between you and Levente (subject line: "SHA512 squeak
>> > > implementation"). Thanks a ton to both of you, BTW, for this work!
>> > >
>> > > After loading
>> > >
>> > > ProCrypto-1-1-1
>> > > and ProCryptoTests-1-1-1,
>> > >
>> > > all 205 tests are passing, however, it took me a bit to realize I need to use
>> > >
>> > > HashFunction newSHA256
>> > >
>> > > instead of
>> > >
>> > > SHA256 new
>> > >
>> > > in order to take advantage of Levente's plugin. This is great, thanks again!
>> >
>> > That is indeed some sort of a change but it only affects those who
>> > compiled the SHA256Plugin themselves since that plugin wasn't shipped with
>> > the VM.
>> > I decided against the practice of making #new return an instance of
>> > another class than the receiver, as it was with the previous
>> > implementation, because that makes it a lot harder for others to
>> > understand the code.
>> >
>> > >
>> > > Quick side question: Is it okay to reuse a SHA256 instance, or should
>> > > I just create a new one for each and every message to hash?
>> >
>> > All subinstances of HashFunction are reusable. The tests
>> > (see HashFunctionTest) do exactly that.
>> >
>> >
>> > Levente
>> >
>> > >
>> > > Best,
>> > > Chris
>> > >
>> > >
>> > > On Sat, Jul 18, 2020 at 6:02 AM Robert Withers
>> [<robert.withers at pm.me>](mailto:robert.withers at pm.me)
>> wrote:
>> > >>
>> > >> Hey Chris,
>> > >>
>> > >> Did this approach fix your issues?
>> > >>
>> > >> Kindly,
>> > >> rabbit
>> > >>
>> > >> On 7/13/20 11:46 PM, Robert wrote:
>> > >>
>> > >> Hi Chris,
>> > >>
>> > >> You should only need to run #3, which will load Registers. Hasher was from before we integrated the code into ProCrypto-1-1-1.
>> > >>
>> > >> Installer as project: ‘Cryptography’; install: ‘ProCrypto-1-1-1’.
>> > >>
>> > >> Then to load tests run:
>> > >>
>> > >> Installer as project: ‘Cryptography’; install: ‘ProCryptoTests-1-1-1’.
>> > >>
>> > >> Let us know if any tests fail and we can look into it.
>> > >>
>> > >> Kindly,
>> > >> Robert
>> > >>
>> > >>
>> > >> On Mon, Jul 13, 2020 at 19:52, Chris Muller
>> [<asqueaker at gmail.com>](mailto:asqueaker at gmail.com)
>> wrote:
>> > >>
>> > >> Hi Robert, hi Levente,
>> > >>
>> > >> I would like to utilize the latest crypto in my next project, would
>> > >> you help me with the current proper way to configure my image, and my
>> > >> vm with plugins?
>> > >>
>> > >> (image)
>> > >> In going back through some recent messages on the mailing lists and
>> > >> instructions on squeaksource.com, I came across these incantations as
>> > >> current ways to load the image code:
>> > >>
>> > >> 1) Installer ss
>> > >> project: 'Registers';
>> > >> install: 'Registers';
>> > >> project: 'Hasher';
>> > >> install: 'HAHasher-Core';
>> > >> install: 'HAHasher-Tests'.
>> > >>
>> > >> 2) Installer ss
>> > >> project: 'Registers';
>> > >> install: 'Registers';
>> > >> project: 'Hasher';
>> > >> install: 'HAHasher'.
>> > >>
>> > >> 3) Installer ss project: 'Cryptography'; install: 'ProCrypto-1-1-1'.
>> > >>
>> > >> I like these one-click-for-everything scripts for crypto -- it
>> > >> satisfies the good use-case of development and education, and also
>> > >> knowing all what's available to Squeak in one glance. My app's build
>> > >> script can cherry pick what it needs, but any advice on which starting
>> > >> point above or otherwise is appreciated.
>> > >>
>> > >> (vm)
>> > >> I put the SHA2Plugin.so from Roberts dropbox in the lib directory,
>> > >> and it shows up as a "Loaded VM Module" in About Squeak. But, three
>> > >> of the "WithPluginTest"'s are failing. My OS is linux_x64. I don't
>> > >> know how to build Squeak or plugins from sources, but including it in
>> > >> the standard precompiled vm would be so pertinent for Squeak today,
>> > >> IMO. SHA256 is one of the ones I'm going to need, so would be nice to
>> > >> have it work via plugin. I assume it's a lot faster?
>> > >>
>> > >> Thanks,
>> > >> Chris
>> > >>
>> > >> On Tue, Mar 10, 2020 at 3:52 PM Levente Uzonyi
>> [<leves at caesar.elte.hu>](mailto:leves at caesar.elte.hu)
>> wrote:
>> > >>>
>> > >>>
>> > >>> Hi Robert,
>> > >>>
>> > >>> With yesterday's help from Eliot and Nicolas, the SHA2Plugin is ready:
>> > >>>
>> http://squeaksource.com/Cryptography/CryptographyPlugins-ul.19.mcz
>>> >>> The updated version of the image-side code is available in the Hasher
>> > >>> repository. You can install it with:
>> > >>>
>> > >>> Installer ss
>> > >>> project: 'Registers';
>> > >>> install: 'Registers';
>> > >>> project: 'Hasher';
>> > >>> install: 'HAHasher-Core';
>> > >>> install: 'HAHasher-Tests'.
>> > >>>
>> > >>>
>> > >>> Levente
>> > >>>
>> > >>>
>> > >>> On Tue, 10 Mar 2020, Levente Uzonyi wrote:
>> > >>>
>> > >>>>
>> > >>>> Hi Robert,
>> > >>>>
>> > >>>> Please have a look at:
>> > >>>>
>> http://lists.squeakfoundation.org/pipermail/squeak-dev/2020-March/207851.html
>>> >>>> It answers all your questions.
>> > >>>>
>> > >>>>
>> > >>>> Levente
>> > >>>>
>> > >>>> On Tue, 10 Mar 2020, Robert wrote:
>> > >>>>
>> > >>>>> Hi Levente,
>> > >>>>>
>> > >>>>> I got the SHA2Plugin built and deployed to my Crypto plugins folder. Now I
>> > >>>> am trying to figure out how to call it from SHA512.
>> > >>>>>
>> > >>>>>
>> https://www.dropbox.com/sh/yhv253rwrhq0q5p/AAB7PKP2KPiGpDnIyule2h_Ia?dl=0
>>> >>>>>
>> > >>>>> [plugin] I looked at it and please understand I think the classes you wrote
>> > >>>> and the framework is really quite nice. I am thrilled we found SHA512! It's
>> > >>>> impressive that your one plugin can handle a number of hash functions!
>> > >>>>> Now all I need is to find the code that calls the SHA2Plugin. Levente,
>> > >>>> would you share that code, please?
>> > >>>>>
>> > >>>>> Kindly,
>> > >>>>> Robert
>> > >>>>>
>> > >>>>>
>> > >>>>
>> > >>
>> > >>
>> > >>
>> > >
>> >
>> >
>> >
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