[tahoe-dev] [pycryptopp] #67: Use of uninitialised value in CryptoPP::Rijndael_Enc_AdvancedProcessBlocks

[pycryptopp]

#67: Use of uninitialised value in  CryptoPP::Rijndael_Enc_AdvancedProcessBlocks
--------------------------+-------------------------------------------------
     Reporter:  Nikratio  |      Owner:  Nikratio
         Type:  defect    |     Status:  new     
     Priority:  major     |    Version:  0.5.19  
   Resolution:            |   Keywords:          
Launchpad Bug:            |  
--------------------------+-------------------------------------------------

Comment (by Nikratio):

 Here you go:

 {{{
 $ valgrind python-dbg contrib/test.py
 ==19162== Memcheck, a memory error detector
 ==19162== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
 ==19162== Using Valgrind-3.6.0.SVN-Debian and LibVEX; rerun with -h for
 copyright info
 ==19162== Command: python-dbg contrib/test.py
 ==19162==
 ==19162== Use of uninitialised value of size 4
 ==19162==    at 0x5121325:
 CryptoPP::Rijndael_Enc_AdvancedProcessBlocks(void*, unsigned int const*)
 (in /usr/lib/libcrypto++.so.8.0.0)
 ==19162==    by 0x512151D:
 CryptoPP::Rijndael::Enc::AdvancedProcessBlocks(unsigned char const*,
 unsigned char const*, unsigned char*, unsigned int, unsigned int) const
 (in /usr/lib/libcrypto++.so.8.0.0)
 ==19162==    by 0x50FC341:
 CryptoPP::CTR_ModePolicy::OperateKeystream(CryptoPP::KeystreamOperation,
 unsigned char*, unsigned char const*, unsigned int) (in
 /usr/lib/libcrypto++.so.8.0.0)
 ==19162==    by 0x4E2405E:
 CryptoPP::CTR_ModePolicy::WriteKeystream(unsigned char*, unsigned int)
 (modes.h:151)
 ==19162==    by 0x505648E:
 CryptoPP::AdditiveCipherTemplate<CryptoPP::AbstractPolicyHolder<CryptoPP::AdditiveCipherAbstractPolicy,
 CryptoPP::CTR_ModePolicy> >::ProcessData(unsigned char*, unsigned char
 const*, unsigned int) (in /usr/lib/libcrypto++.so.8.0.0)
 ==19162==    by 0x4E23A5D: AES_process(AES*, _object*) (aesmodule.cpp:77)
 ==19162==    by 0x80F92A8: call_function (ceval.c:3738)
 ==19162==    by 0x80F4ACA: PyEval_EvalFrameEx (ceval.c:2412)
 ==19162==    by 0x80F98F3: fast_function (ceval.c:3836)
 ==19162==    by 0x80F964C: call_function (ceval.c:3771)
 ==19162==    by 0x80F4ACA: PyEval_EvalFrameEx (ceval.c:2412)
 ==19162==    by 0x80F7214: PyEval_EvalCodeEx (ceval.c:3000)
 ==19162==
 [19593 refs]
 ==19162==
 ==19162== HEAP SUMMARY:
 ==19162==     in use at exit: 565,451 bytes in 5,895 blocks
 ==19162==   total heap usage: 51,971 allocs, 46,076 frees, 5,439,309 bytes
 allocated
 ==19162==
 ==19162== LEAK SUMMARY:
 ==19162==    definitely lost: 0 bytes in 0 blocks
 ==19162==    indirectly lost: 0 bytes in 0 blocks
 ==19162==      possibly lost: 544,863 bytes in 5,576 blocks
 ==19162==    still reachable: 20,588 bytes in 319 blocks
 ==19162==         suppressed: 0 bytes in 0 blocks
 ==19162== Rerun with --leak-check=full to see details of leaked memory
 ==19162==
 ==19162== For counts of detected and suppressed errors, rerun with: -v
 ==19162== Use --track-origins=yes to see where uninitialised values come
 from
 ==19162== ERROR SUMMARY: 2 errors from 1 contexts (suppressed: 50 from 11)
 }}}


 {{{
 $ cat contrib/test.py
 import hmac
 import pycryptopp
 import hashlib
 import struct

 def encrypt(buf, passphrase, nonce):

     key = hashlib.sha256(passphrase + nonce).digest()
     cipher = pycryptopp.cipher.aes.AES(key)
     hmac_ = hmac.new(key, digestmod=hashlib.sha256)

     hmac_.update(buf)
     buf = cipher.process(buf)
     hash_ = cipher.process(hmac_.digest())

     return b''.join(
                     (struct.pack(b'<B', len(nonce)),
                     nonce, hash_, buf))

 encrypt('foobar', 'passphrase', 'nonce')
 }}}

-- 
Ticket URL: <http://allmydata.org/trac/pycryptopp/ticket/67#comment:2>
pycryptopp <http://allmydata.org/trac/pycryptopp>
Python bindings for the Crypto++ library