I had some passwords saved in remmina but like it always happen, I wasn’t been able to remember them when needed. Trying to restore them I found that they’re encrypted in .remmina directory.
Then I used this script to decrypt them 1:
Extract script
import base64
from Crypto.Cipher import DES3
secret = base64.decodestring("<STRING FROM remmina.prefs>")
password = base64.decodestring("<STRING FROM XXXXXXX.remmina>")
print DES3.new(secret[:24], DES3.MODE_CBC, secret[24:]).decrypt(password)