i found a workaround for using kwallet with new version of sync authentication Rated 1 out of 5 stars

in FF
disconnect from sync service
unactivate kwallet plugin
restart FF

check that kwallet plugin is well unactivated

connect to sync service
go to FF password manager
copy somewhere the password of "Chrome://FirefoxAccounts (Firefox Accounts credentials)"
activate kwallet plugin

in kwallet manager replace the password of "Chrome://FirefoxAccounts" by the password you copied somewhere

restart FF

enjoy !

my explication : passwords(tokens) delivered with or without kwallet manager activated are different

with kwallet activated
{"version":1,"accountData":{"sessionTokenContext":"fx_desktop_v1","unwrapBKey":"d92...fe7","keyFetchToken":"6vg...3eb","customizeSync":false}}

with kwallet unactivated
{"version":1,"accountData":{"sessionTokenContext":"fx_desktop_v1","customizeSync":false,"kA":"65...09","kB":"01...46"}}

sync autentication fails Rated 1 out of 5 stars

see my bug report here

https://bugzilla.mozilla.org/show_bug.cgi?id=1135632

and
here page 8 " FF 35.0,sync authentication pb"

http://kde-apps.org/content/show.php?content=116886&forumpage=7

2.2, crash , my solution Rated 1 out of 5 stars

opensuse 13.1 x86_64 , kde 4.12 , firefox 26 , kwallet 2.2

i use the former way to use kwallet wiht my mandriva kde 4.8.4 and the old kwallet application

- i choose bluefish encrypting (the old way) for kwallet (new feature for kde 4.12 you have the choice to crypt with bluefish or a public/private key technology)

- in settings>wallet settings , in "kde wallet settings" tab
i uncheck all about "wallet closing" and all about thumbnail and systray

- in settings>wallet settings , in "access control" tab
i check "ask for an authorization when an application accesses to a wallet"

when kwallet asks for you how to authorize an application to access to the wallet
then
answer "always"
you may have one or two crashes but after no more pb

additional info :
- i have many many id,pwd
- i wonder if the new kwallet application (not the same between kde 4.8.4 and 4.12) is a bit buggy

This review is for a previous version of the add-on (2.2.1-signed.1-signed). 

2.2,firefox asks kwallet pwd to open an already opened kwallet Rated 1 out of 5 stars

mandriva 2010.1 i686 , kde 4.8.5 , firefox 26 , kwallet 2.2

i open a kde session
then
kmail asks for me the kwallet password to open kwallet
then
i launch ff
then
ff does not asks for me the kwallet pwd
ff can uses ids and pwds stored in kwallet without any pb

opensuse 13.1 x86_64 , kde 4.12 , firefox 26 , kwallet 2.2

i chose bluefish encrypting (the old way) for kwallet (new feature for kde 4.12 you have the choice to crypt with bluefish or a public/private key technology)

i open a kde session
then
kmail asks for me the kwallet pwd to open kwallet
then
i launch ff
then
firefox asks for me the kwallet pwd to open kwallet !

i go back to 2.1 then same pb

i assume a pb around kde 4.12 , kwallet 2.0 , fiefox 26 , kwallet extension

i return to 2.2
then
no more pb : ff does not asks for me the kwallet password

it seems that 2.1 repaired something .

i assume 2.1 repaired the access/authorization part

This review is for a previous version of the add-on (2.2.1-signed.1-signed). 

2.2 version -> firefox crash Rated 1 out of 5 stars

opensuse 13.1 x86_64 , kde 4.12 , firefox 26 , kwallet 2.2

firefox randomly crashes and too often .
it's an actual pb

mandriva 2010.1 i686 , kde 4.8.5 , firefox 26 , kwallet 2.2

no pb

i go back to 2.1 then no more crash

with 2.1 i get pb : when opening asession in a site then id and pwd are well filled
but login fails
then
i return to 2.2
then
no more pb for login
and
a good news : no more crash

it seems that 2.1 repaired something

This review is for a previous version of the add-on (2.2.1-signed.1-signed). 

with firefox 24 not working Rated 5 out of 5 stars

my config : mandriva 2010 i586,kde 4.8.4

i have since many version of firefox kdewallet addon.it works well . thanks

when updating to firefox 24 then it still works

recently firefox was broken due to something wrong in .mozilla folder
then i remove .mozilla folder
then i launch firefox
then i install kdewallet
then i relaunch firefox
then it does not ask the opening of kwallet

when reaching some url with template to sign in
then firefox does not fill the fields

update

i made an error .for firefox asking kwallet opening the option "record paswword" must be checked

but still remains "fields are not filled" pb

update

it seems only a part of the template has a pb

openstreetmap.org : connexion template is filled
bugs.kde.org : login template is not filled

the 2 are well in kwallet file

when i fill the kde.org login template then firefox does not ask if i want to record the password.

update

i suppress bugs.kde.org login data in kdewallet
then i log in bugs.kde.org
then this time firefox asks for me if i want to record the password
then i answer yes
then i see the login data is well recorded in kdewallet
then i go again to bugs.kde.org login
then the fields are not filled !

update

with addons.mozilla.org i had the same pb
but
i do the same things as for bugs.kde.org login
then
now no more pb

what is the difference between bugs.kde.org and addons.mozilla.org ?

This review is for a previous version of the add-on (2.1.1-signed.1-signed). 

kdesecrets technology Rated 5 out of 5 stars

do you know ?
with kde sc 4.8 there is a new technology : ksecretservice

KSecretService is a new framework for sharing saved passwords and other credentials between a wider range of applications. KSecretService uses KDE's well-known interfaces through a Freedesktop-compliant API with other password systems, transparently for the user. KSecretService improves integration of KDE applications into other workspaces and allows 3rd party applications to plug into KDE's secure password saving system.

Perhaps this will be easier for you to develop your plugin ?

This review is for a previous version of the add-on (1.0.9). 

KSecretService

Yes, I've been following KSecretService for a while, but I can't get enough information on how to connect to it, I think I will have to wait a bit, and hope that it's kwallet legacy support really works

Rated 5 out of 5 stars

please
add the info your addon is compliant with firefox 3.6 according to install it with firefox 3.6

This review is for a previous version of the add-on (0.4). 

kde 3.5.9 ? Rated 3 out of 5 stars

is it compliant with kde 3.5.9 kwallet ?

This review is for a previous version of the add-on (0.4). 

KDE 3.5.X

I haven't tried, but I think kwallet library have a different name in KDE 3.5, so, may be recompiling against that library it should work.