Need advices on Qt + JSON + cryptography

[remy_david]

Hi all,

I am new to Qt but not to C++ & mobile development.
I need your help to know if my project can be done and how.

What I need :
- Target my applicaiton to Symbian S60 5th edition and Symbian^3 devices
- Use cryptography (DES or AES)
- Use a JSON parser
- Use Qt SDK & Qt Creator

Problems that I can see :
- Qt SDK API do not support cryptography
- Qt SDK API do not support JSON

Solutions that I can see:
- Use external C++ JSON & cryptography libraries
Is this possible ? what condition must be met by these library to integrate well in Qt SDK ? Do you know which one ? Is there another solution ? (use Symbian C++ API ?)

Thanks

[divanov]

All problems has been discussed here. Search is your friend.

[danhicksbyron]

There is a good crypto library in the native Symbian code. It is relatively easy to access (though a bit obscure to interface with) if you get the right interface stuff. Google "SymbianCryptographyLibraries.zip" to find a copy on the net. (Nokia doesn't make it readily available, but several other sources do.) (Note, for legal reasons you want to use the crypto code built into the phone vs shipping your own and running afoul of import/export regulations.)

There are some rather bloated open source JSON libraries available on the net, or you can write your own Qt version in about 1000 lines of code -- it's a relatively simple exercise. (I'd make mine available except that it belongs to my employer.)

[remy_david]

@ danhicksbyron : Thanks, I will look in that directions.

@ divanov : I understand your point, but I think you can't imagine how hard it is for someone not familiar with Nokia mobile development to find UP TO DATE answer to technical questions BEFORE actually starting to use Nokia mobile tools and frameworks. Event for an experienced C++ & (non-Nokia) mobile developer.

[divanov]

@ divanov : I understand your point, but I think you can't imagine how hard it is for someone not familiar with Nokia mobile development to find UP TO DATE answer to technical questions BEFORE actually starting to use Nokia mobile tools and frameworks. Event for an experienced C++ & (non-Nokia) mobile developer.

You didn't sell that to me.

[danhicksbyron]

The trick is to learn how to use Google effectively. If you Google "qt json site:forum.nokia.com" you will get several references on using JSON (including this thread). The "site:forum.nokia.com" limits your search to this site, greatly reducing the "noise".

[remy_david]

I have trouble on how to use Symbian API in Qt SDK.
I found this:
http://developer.symbian.org/wiki/Us...n_C++_Together
but it does not describe how to set up the environment.

For now, I tried to use the Symbian cryptographic API, but I am stuck on how to import it correctly into Qt Creator.

I installed C/C++ plugins, then installed the cryptography API from here:
http://wiki.forum.nokia.com/index.ph...ptography_APIs

Then I copied the corresponding .h in C:\NokiaQtSDK\Symbian\SDK\epoc32

I edited my project .pro to add

INCLUDEPATH += C:\NokiaQtSDK\Symbian\SDK\epoc32\include
LIBS+= -lcryptography \
              -leuser // edited

At compilation I have the same problem that this guy:
http://discussion.forum.nokia.com/fo...hlight=symbian

g++ -c -g -frtti -fexceptions -mthreads -Wall -DUNICODE -DQT_LARGEFILE_SUPPORT -DQT_DLL -DQT_GUI_LIB -DQT_CORE_LIB -DQT_THREAD_SUPPORT -DQT_NEEDS_QMAIN -I"..\..\Simulator\Qt\mingw\include\QtCore" -I"..\..\Simulator\Qt\mingw\include\QtGui" -I"..\..\Simulator\Qt\mingw\include" -I"..\..\Symbian\SDK\epoc32\include" -I"..\..\Simulator\Qt\mingw\include\ActiveQt" -I"debug" -I"." -I"..\encrypttest" -I"." -I"..\..\Simulator\Qt\mingw\mkspecs\win32-g++" -o debug\main.o ..\encrypttest\main.cpp

n file included from ..\..\Symbian\SDK\epoc32\include/e32cmn.h:1104,

                 from ..\..\Symbian\SDK\epoc32\include/e32std.h:13,

                 from ..\..\Symbian\SDK\epoc32\include/e32base.h:8,

                 from ..\..\Symbian\SDK\epoc32\include/cryptosymmetric.h:20,

                 from ..\encrypttest\/mainwindow.h:12,

                 from ..\encrypttest\main.cpp:8:

..\..\Symbian\SDK\epoc32\include/e32des16.h:691:2: error: #error no typedef for __TText

In file included from ..\..\Symbian\SDK\epoc32\include/e32err.h:13,

                 from ..\..\Symbian\SDK\epoc32\include/e32const.h:9,

                 from ..\..\Symbian\SDK\epoc32\include/e32cmn.h:8,

                 from ..\..\Symbian\SDK\epoc32\include/e32std.h:13,

                 from ..\..\Symbian\SDK\epoc32\include/e32base.h:8,

                 from ..\..\Symbian\SDK\epoc32\include/cryptosymmetric.h:20,

                 from ..\encrypttest\/mainwindow.h:12,

                 from ..\encrypttest\main.cpp:8:

..\..\Symbian\SDK\epoc32\include/e32def.h:872: error: 'Int64' does not name a type

..\..\Symbian\SDK\epoc32\include/e32def.h:883: error: 'Uint64' does not name a type

In file included from ..\..\Symbian\SDK\epoc32\include/e32cmn.h:8,

                 from ..\..\Symbian\SDK\epoc32\include/e32std.h:13,

                 from ..\..\Symbian\SDK\epoc32\include/e32base.h:8,

                 from ..\..\Symbian\SDK\epoc32\include/cryptosymmetric.h:20,

                 from ..\encrypttest\/mainwindow.h:12,

                 from ..\encrypttest\main.cpp:8:

..\..\Symbian\SDK\epoc32\include/e32const.h:860: error: 'TInt64' does not name a type

..\..\Symbian\SDK\epoc32\include/e32const.h:871: error: 'TInt64' does not name a type

..\..\Symbian\SDK\epoc32\include/e32const.h:882: error: 'TUint64' does not name a type

In file included from ..\..\Symbian\SDK\epoc32\include/e32std.h:13,

                 from ..\..\Symbian\SDK\epoc32\include/e32base.h:8,

                 from ..\..\Symbian\SDK\epoc32\include/cryptosymmetric.h:20,

                 from ..\encrypttest\/mainwindow.h:12,

                 from ..\encrypttest\main.cpp:8:

..\..\Symbian\SDK\epoc32\include/e32cmn.h:41: error: 'IMPORT_C' does not name a type

Thanks in advance for any advice.

[danhicksbyron]

Should be:

LIBS+= -lcryptography \
              -leuser

[remy_david]

Thank you for pointing this, but I have the same errors. However I edited my last post to reflect the change.

Correct me if I am wrong, but I think it is not a lib problem because the errors arise at compilation time. I think I am missing the right headers, but which ones ?

[danhicksbyron]

Yeah, you appear to have a configuration problem. Not unusual, and not something I know much about.

[remy_david]

I am still stuck with using Symbian C++ into Qt Creator, I leave the crypto API appart for the moment, I just want to compile a single Symbian C++ line of code to be sure my configuration is correct:

TUInt32 i = 0;

Should be simple, right ?

To summarize, here is what I did:
- Install S60 SDK
- Install Qt SDK
- Install open C/C++ plugins
- Install Qt for Symbian into S60 SDK (don't think it is necessary though)
- Create a new Qt project in Qt Creator
- Add S60 SDK include path to the .pro
- Add LIBS+= -leuser to the .pro

Now if I import "e32def.h" or any other Symbian C++ header in my empty project, I got hundreds of errors like

..\..\Symbian\SDK\epoc32\include/e32des16.h:691:2: error: #error no typedef for __TText
..\..\Symbian\SDK\epoc32\include/e32def.h:872: error: 'Int64' does not name a type
..\..\Symbian\SDK\epoc32\include/e32def.h:883: error: 'Uint64' does not name a type

If I don't add any header and simply add "TUInt32 i = 0;" to my .cpp main, I also got error: 'TUint32' does not name a type

Any help would be really appreciated.
Qt and Nokia Qt SDK are great but are still laking some basics APIs. If we cannot easily reach native APIs to overcome this, the whole thing is quite useless.

Thanks

[danhicksbyron]

What do you get if you type "devices" in a command window?

[remy_david]

Thanks for your reply.

I have:

Nokia_N97_SDK_v1.0:com.nokia.s60 - default
S60_3rd_FP2_SDK_v1.1:com.nokia.s60
S60_5th_Edition_SDK_v1.0:com.nokia.s60

Same appens if I change the default SDK.

[danhicksbyron]

It would be nice if someone would write up how to do this. I don't think you should have to add the S60 SDK to INCLUDEPATH. And I think you may have installed one SDK too many.

[remy_david]

From what I understand what I was trying to do is not possible. You cannot use native Symbian code / API in Qt Simulator.
What we should be able to do however is to run it into the Symbian SDK Emulators. So far I did not find how to do that.

I can only select "S60_5th_Edition_SDK_v1.0 (Qt 4.7.1)" as a "Symbian Device" target, so Qt Creator wants a real device to be connected. I don't know how to tell him to launch the SDK Emulator instead.
Anyone ?