Quelques questions pour guider tes recherches (suit les numéros) :
1) Quelle version des logiciels utilises-tu ? fxRemote ou pfxRecover ?
- pfxRecover
5
- fxRemote
2
2) Quelle étape ne fonctionne pas ?
- Backup Flash
3
- Recover Flash
4
3) Théoriquement, tu n'as pas besoin de faire de backup. Il y en a de partout sur le site. 
4) As-tu fait la manip' pour la mettre en mode "OS Error" (pour le mode "Recover Flash") ?
- Oui
6
- Non
7
5) Commence par installer fxRemote disponible ici puis réessaye. Si ça ne marche toujours pas,
2
6) As-tu vérifié à bien prendre un OS de même version que celui de ta G35+USB ? La version de l'OS se trouve dans le menu "Système" -> [F4]. Si votre OS est du type 02.0
0.**** ou 02.0
1.****, prenez une version 02.0
1.****. Si c'est un 02.0
2.****, prenez un 02.0
2.****. Attention, un OS contenant le mot "slim" n'est pas pour vous, il s'adresse aux anglophones possédant
ce modèle. Si vous l'installez, vous aurez surement tout un tas de bugs !
- Oui
8
- Non
9
7) Met la calto en mode "OS Error". Pour cela, suis les étapes suivantes :
- Appuie sur "Restart" (avec un stylo par exemple) au dos de ta calto (NB: ça n'efface rien du tout dans la mémoire)
- Tout en appuyant sur "Restart", appuie en même temps sur "F2" - "4" - "Ac/ON"
- Relâche le bouton "Restart", mais garde pressés les autres.
- Relâche tout, et successivement, appuie sur "9" puis "X" (au dessus du "+").
Puis
10
8) Je t'invite à laisser un message sur le forum, ton cas me parait désespéré. Fais attention à bien décrire ton problème (erreur, etc.)
9) Prend le bon OS. Si tu ne sais pas comment ça marche, un OS 02.01.2020 correspond à un fichier OS_02_01_2020_SH3.fls.
Puis recommence la manipulation (à partir de Recover Flash)
10) Le message "OS Error, please update OS" s'affiche-t-il à l'écran de ta Casio ?
- Oui : branche ta casio à l'ordinateur, lance fxRemote, puis fait "Recover". Si tu as toujours un problème,
6
- Non : Recommence la manipulation du 7.
- Cela fait 3-4 fois que je refais la manip', mais je n'obtient toujours rien : courage, tu va y arriver. Essaye d'allonger un peu les temps entre l'appui sur les touches. Inutile de se presser
Citer : Posté le 23/08/2015 22:14 | #
D'un coté, tu indiques suffisamment comment faire pour patcher son propre fxRemote
M'enfin, c'est bon à savoir, pour ceux qui ont les connaissances nécessaires.
Citer : Posté le 23/08/2015 22:16 | #
C'est tellement facile que c'est à la portée de n'importe qui se penchant un peu sérieusement sur la dernière version de fxRemote pour comprendre ce qui ne va pas, ce que j'ai fait hier soir.
Ajouté le 23/08/2015 à 22:17 :
Honestly, I agree with saying that sharing the new version of fxRemote isn't a good idea... because once released, there is no possible control of how people would use this tool, and I'm afraid that it would have consequences when working with exam models, although there were none with old calculators.
The consequences will be for the users, if they are stupid enough to apply illegal patches to their OS.
Citer : Posté le 23/08/2015 22:20 | #
The consequences will be for the users, if they are stupid enough to apply illegal patches to their OS.
There will be stupid enough users. And I personnally don't want Casio to take measures to enhance security on these calculators.
Although it's not as if we had broken the exam mode, I don't think Casio will let users manipulate these models, whose security is critical during exams.
Citer : Posté le 23/08/2015 22:22 | #
Ok.
So now the question is : in the Casio community, do we have developpers both skilled and stupid enough to release illegal exam mode patches for France ?
Citer : Posté le 23/08/2015 22:24 | #
In a certain way, Casio, TI and other constructors must add an exam mode on their calcs, they don't have to ensure that this protection will not be overridden. So, it is not as critical as it seems.
Citer : Posté le 23/08/2015 22:25 | #
Sincerely, I don't think anyone here would match these conditions. But I've seen enough developers selling doubtful applications and uncareful retro-engineers that could be skilled enough to reverse the exam mode.
But it would mean that there isn't anything we can do to prevent this from happening eventually... there's three years. I don't think it would take more than three weeks to someone skilled to break this security...
Citer : Posté le 23/08/2015 22:25 | #
I wonder how long it will take until someone puts a modified fxRemote on the Internet?
Citer : Posté le 23/08/2015 22:27 | #
In a certain way, Casio, TI and other constructors must add an exam mode on their calcs, they don't have to ensure that this protection will not be overridden. So, it is not as critical as it seems.
Yeah, but if they strengthen the calculator security they won't hesitate to remove add-in application support and other functionalities that are, from our point of view, critical.
Citer : Posté le 23/08/2015 22:28 | #
I wonder how long it will take until someone puts a modified fxRemote on the Internet?
I don't know. The idea is quite basic.
But, I did omit on purpose two tiny technical things in my post :
https://tiplanet.org/forum/viewtopic.php?p=187492#p187492
Just patching the "2011.0525.1010" string to "2011.0531.1709" in fxRemote.exe won't be enough to make it work.
Citer : Posté le 23/08/2015 22:31 | #
So now the question is : in the Casio community, do we have developpers both skilled and stupid enough to release illegal exam mode patches for France ?
Both skilled, I think. Stupid to make these patch, yes. Stupid enough to release it on the Web? No.
To make comparaison, TI are as easy to hack ?
Ajouté le 23/08/2015 à 22:34 :
By the way, have you make a backup of the G35+E OS ?
Citer : Posté le 23/08/2015 23:08 | #
In a certain way, Casio, TI and other constructors must add an exam mode on their calcs, they don't have to ensure that this protection will not be overridden. So, it is not as critical as it seems.
Yeah, but if they strengthen the calculator security they won't hesitate to remove add-in application support and other functionalities that are, from our point of view, critical.
They've already removed add-in application support on the :
- Classpad 330+
- fx-CP400
- Graph 75+E when put in exam mode (even official add-ins like Physium cannot be used in exam mode, unlike TI calculators)
They did already take that path - I don't think what we're doing is going to change anything. It's probably already on their todo list.
Graph 25+E/35+E/75+E just seem to be a quick hack/tinker of the older Graph 25+Pro/35+USB/75 models.
They didn't fix anything, they didn't enhance the security which is non-existent compared to TI or HP calculators.
They're probably already working on new models with enhanced security to be released before 2018.
Or at least, that's what they should be doing if you check the latest TI-83 Premium CE...
Ajouté le 23/08/2015 à 23:18 :
So now the question is : in the Casio community, do we have developpers both skilled and stupid enough to release illegal exam mode patches for France ?
Both skilled, I think. Stupid to make these patch, yes. Stupid enough to release it on the Web? No.
To make comparaison, TI are as easy to hack ?
TI calculators are far more secured than Casio Graph calculators.
You can't flash a patched OS, because OSes are signed with a 2048-bits RSA key.
The OS integrity is checked upon installation, and on some models on each boot.
So running a patched OS is difficult, and making it permanent is even more difficult.
Ajouté le 23/08/2015 à 22:34 :
By the way, have you make a backup of the G35+E OS ?
Yes, I did.
Citer : Posté le 23/08/2015 23:18 | #
And it is not because that addin applications can be removed that we wouldn't be able to hack the OS. I think it is too late to keep addins on next models. Critor is right, Casio work on new models. Graph *5+E are just low-cost enhancements of older models. Addin are going to be blocked anyway. It's just a matter of time.
Ajouté le 23/08/2015 à 23:22 :
Is on the net explanations on the way that Ndless works? It can be misused no?
Citer : Posté le 23/08/2015 23:31 | #
Ajouté le 23/08/2015 à 23:22 :
Is on the net explanations on the way that Ndless works? It can be misused no?
It exploits flaws in the OS or Boot2 code.
You've got the source code on the Internet.
As far as I know there are no details about the flaws, as each time a flaw is being exploited, TI does fix it in the next OS update, and Ndless has to switch to another flaw.
And yes, Ndless could perfectly be used to tinker with the exam mode.
For now it isn't - maybe because there are very few active Ndless programs developpers in the world, me included.
I think a single hand is currently enough to count them...
Citer : Posté le 24/08/2015 01:14 | #
They've already removed add-in application support on the :
- Classpad 330+
- fx-CP400
- Graph 75+E when put in exam mode (even official add-ins like Physium cannot be used in exam mode, unlike TI calculators)
The ClassPad 330 Plus supports add-ins. It uses the .c1a format which is based on the .g3a format. Yet, there is no public SDK to build .c1a files and the only known official add-in is Algy2.c1a
Providing an SDK doesn't make sense for Casio anymore because there are so few programmers out there who do interesting mathematical or educational stuff. And because there are no public SDKs, they can now remove add-in support altogether. I don't think that they really care about security.
Citer : Posté le 24/08/2015 01:25 | #
But the Fx-CP400 not. On this model, Algy 2 is already into the OS.
If so, what are you affraid of?
Citer : Posté le 24/08/2015 01:49 | #
If so, what are you affraid of?
They may not care now, but they may be "forced" to care about it.
This depends on how many people and who complains about specific issues.
Citer : Posté le 09/09/2015 14:46 | #
Donc pour tous ce qui on une Graph 35+E ça ne seras pas possible de mettre un Firmwares de 75+E ??
Citer : Posté le 09/09/2015 14:47 | #
Si.
https://tiplanet.org/forum/viewtopic.php?p=187492#p187492
Citer : Posté le 09/09/2015 14:59 | #
Merci !
La manipulation est donc la même ?
(Graph35+ a Graph 75+ ?)
Mais où trouve-t-on l'os ?
Citer : Posté le 09/09/2015 21:41 | #
J'ai une question, quel est cet étrange fxRemote-E.exe disponible dans la bible Casio sur Mega ?
Serait-il capable de flasher les graph35+E ? Cela serait un danger pour le mode examen de l'avoir mis en public...
Citer : Posté le 09/09/2015 22:23 | #
fxRemote-E est une version de fxRemote hackée par Critor, qui permet en effet de flasher un OS de G75+E sur les G35+E.
Pour avoir fait des tests sur la sécurité du ME, je doute fort que ce soit un danger, puisqu'en effet celui-ci n'est pas stocké dans l'OS (on peut changer l'OS sans désactiver le ME).
D'un autre coté, tu dois être bien renseigné, la Bible Casio est pas très visible sur le site (à moins que Critor ait diffusé le lien sur TIP), même si en effet nous ne pratiquons pas la censure de ce genre d'outil.