XPCOM Encrypt / Decrypt file operation in Firefox Extension

Question

My Firefox extension needs;

• save user credentials in file, which will be stored by users of the local file system .
• when credentials are needed, decrypt the file, read the values ​​and encrypt again.
• sometimes send an encrypted file on top of http to the server.

I can not find any XPCOM component to encrypt / decrypt a file. Should I write my own XPCOM object or is there some other reasonable solution for this.

[Note:] This may appeal to the Firefox password management system. Firefox stores the master password and keys in the key3.db file and uses these values ​​to access the credentials stored in the signons.sqlite file.

Firefox uses the nsILoginManager interface for its operations.

Answer 1

XPCOM NSS. js-ctypes NSS - , . WeaveCrypto.js . DOMCrypt , WeaveCrypto.js ( , , - , API ).