linux has "equivalent protected-storage APIs integrated throughout the desktop environment",KDE has kwallet[1],GNOME has libsecret[2] and lxqt has lxqt wallet[3].Firefox has an extension to store its passwords in KDE's kwallet[4] and GNOME's gnome-keyring/libsecret[5].Chrome has support for both wallets[6]

all linux destributions ships with libsecret and that will be the API to target if anybody want to store sensitive information securely in a linux desktop session.

[1] http://en.wikipedia.org/wiki/KWallet

[2] http://lwn.net/Articles/490518/

[3] https://github.com/mhogomchungu/lxqt_wallet

[4] https://addons.mozilla.org/en-US/firefox/addon/kde-wallet-pa...

[5] https://addons.mozilla.org/en-Us/firefox/addon/gnome-keyring...

[6] http://productforums.google.com/forum/#!topic/chrome/r65mTFM...