bazarr/libs/beaker/crypto/nsscrypto.py

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"""Encryption module that uses nsscrypto"""
import nss.nss
nss.nss.nss_init_nodb()
# Apparently the rest of beaker doesn't care about the particluar cipher,
# mode and padding used.
# NOTE: A constant IV!!! This is only secure if the KEY is never reused!!!
_mech = nss.nss.CKM_AES_CBC_PAD
_iv = '\0' * nss.nss.get_iv_length(_mech)
def aesEncrypt(data, key):
slot = nss.nss.get_best_slot(_mech)
key_obj = nss.nss.import_sym_key(slot, _mech, nss.nss.PK11_OriginGenerated,
nss.nss.CKA_ENCRYPT, nss.nss.SecItem(key))
param = nss.nss.param_from_iv(_mech, nss.nss.SecItem(_iv))
ctx = nss.nss.create_context_by_sym_key(_mech, nss.nss.CKA_ENCRYPT, key_obj,
param)
l1 = ctx.cipher_op(data)
# Yes, DIGEST. This needs fixing in NSS, but apparently nobody (including
# me :( ) cares enough.
l2 = ctx.digest_final()
return l1 + l2
def aesDecrypt(data, key):
slot = nss.nss.get_best_slot(_mech)
key_obj = nss.nss.import_sym_key(slot, _mech, nss.nss.PK11_OriginGenerated,
nss.nss.CKA_DECRYPT, nss.nss.SecItem(key))
param = nss.nss.param_from_iv(_mech, nss.nss.SecItem(_iv))
ctx = nss.nss.create_context_by_sym_key(_mech, nss.nss.CKA_DECRYPT, key_obj,
param)
l1 = ctx.cipher_op(data)
# Yes, DIGEST. This needs fixing in NSS, but apparently nobody (including
# me :( ) cares enough.
l2 = ctx.digest_final()
return l1 + l2
has_aes = True
def getKeyLength():
return 32