var_editor script helps editing encrypted files

bin/var_editor.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+
+import os, sys, tempfile,getopt
+from cryptography.fernet import Fernet
+
+def main():
+    try:
+        opts, args = getopt.getopt(sys.argv[1:],'k:K:n')
+    except:
+        usage()
+        sys.exit(2)
+    
+    key = ''
+    for opt, val in opts:
+        if opt == '-n':
+            # Print a new key and exit
+            print(Fernet.generate_key().decode())
+            exit(0)
+        if opt == '-k':
+            key = val
+        elif opt == '-K':
+            key = open(arg, 'rb').read()
+    
+    if key == '':
+        usage()
+        sys.exit(2)
+
+    # Create a fernet object using our key
+    f = Fernet(key)
+    # This temp file will hold the decrypted content while we edit it
+    tmp = tempfile.NamedTemporaryFile()
+    # We open the file, which contains the encrypted content
+    crypt = open(args[0], 'rb').read()
+    # And we decrypt it, and write it in the temp file
+    clear = f.decrypt(crypt)
+    tmp.write(clear)
+    tmp.flush()
+    # Now, lets open our favorite editor to edit the file
+    os.system(os.getenv('EDITOR', 'vim') + ' ' + tmp.name)
+    # We closed the editor, we just have to open the cleartext file, encrypt its content
+    # and save it
+    clear = open(tmp.name, 'rb').read()
+    os.unlink(tmp.name)
+    wcrypt = open(args[0], 'wb')
+    wcrypt.write(f.encrypt(clear))
+    wcrypt.flush()
+    wcrypt.close()
+
+def usage():
+    print(argv[0] + ' [-k secret] [-K ./secret.txt] variables.json')
+
+if __name__ == '__main__':
+    main()