PyCrypto: AssertionError ("The PID failed. RNG should be reinitialized after fork (). Hint: try Random.atfork ()")

Question

I create various processes that perform different tasks. One of them and only one of them has a security module that creates PyCrypto objects. Therefore, my program starts up, creates various processes, the process that processes the messages, uses the security module for decryption, and I get the following errors:

firstSymKeybin = self.cipher.decrypt(encFirstSymKeybin, '') File "/usr/local/lib/python2.7/dist-packages/Crypto/Cipher/PKCS1_v1_5.py", line 206, in decrypt m = self._key.decrypt(ct) File "/usr/local/lib/python2.7/dist-packages/Crypto/PublicKey/RSA.py", line 174, in decrypt return pubkey.pubkey.decrypt(self, ciphertext) File "/usr/local/lib/python2.7/dist-packages/Crypto/PublicKey/pubkey.py", line 93, in decrypt plaintext=self._decrypt(ciphertext) File "/usr/local/lib/python2.7/dist-packages/Crypto/PublicKey/RSA.py", line 235, in _decrypt r = getRandomRange(1, self.key.n-1, randfunc=self._randfunc) File "/usr/local/lib/python2.7/dist-packages/Crypto/Util/number.py", line 123, in getRandomRange value = getRandomInteger(bits, randfunc) File "/usr/local/lib/python2.7/dist-packages/Crypto/Util/number.py", line 104, in getRandomInteger S = randfunc(N>>3) File "/usr/local/lib/python2.7/dist-packages/Crypto/Random/_UserFriendlyRNG.py", line 187, in read return self._singleton.read(bytes) File "/usr/local/lib/python2.7/dist-packages/Crypto/Random/_UserFriendlyRNG.py", line 163, in read return _UserFriendlyRNG.read(self, bytes) File "/usr/local/lib/python2.7/dist-packages/Crypto/Random/_UserFriendlyRNG.py", line 122, in read self._check_pid() File "/usr/local/lib/python2.7/dist-packages/Crypto/Random/_UserFriendlyRNG.py", line 138, in _check_pid raise AssertionError("PID check failed. RNG must be re-initialized after fork(). Hint: Try Random.atfork()") AssertionError: PID check failed. RNG must be re-initialized after fork(). Hint: Try Random.atfork() 

Decryption works well interactively when not called from a process.

My security module is as follows:

 ''' Created on 25 Apr 2013 @author: max ''' import base64, ast, binascii from Crypto.Cipher import AES from Crypto.Cipher import PKCS1_v1_5 from Crypto.PublicKey import RSA import br_consts class SecurityMod(object): ''' classdocs ''' def __init__(self): ''' Constructor ''' super(SecurityMod,self).__init__() self.privkey = RSA.importKey(open('./privkeyBR.pem', 'r').read()) self.cipher = PKCS1_v1_5.new(self.privkey) self.ridToKeySalt = {} #depending on the type of message, encryption format is different def encrypt(self, msg, rqId, rid): ##code return encMsg #return string of object so it can be parse by JSON def decrypt(self, encMsg, rqId, rid): #code return msgObjStr def pad_data(self,data): if len(data) == 0: return data if len(data) % 16 == 0: padding_required = 15 else: padding_required = 15 - (len(data) % 16) data = '%s\x80' % data data = '%s%s' % (data, '\x00' * padding_required) return data def unpad_data(self,data): if not data: return data data = data.rstrip('\x00') if data[-1] == '\x80': return data[:-1] else: return data 

Answer 1

You need to call Crypto.Random.atfork() after os.fork()

I just put __init__() in the security module in front of others