getPrime with invalid input causes Python to abort with fatal error

[Legrandin]

The following code:

  from Crypto import Random
  from Crypto.Util.number import *

  getPrime(1, Random.new().read)

always makes python raise an exotic exception:

  Fatal Python error: PyEval_SaveThread: NULL tstate

Any Pycrypto version up to 2.5.0 on x86.

[Darsey Litzenberger (dlitz)]

Here's the place where it fails:

#4 0x00007f343a5c2379 in isPrime (self=<optimized out>, args=<optimized out>, kwargs=<optimized out>) at src/_fastmath.c:1046
1046 Py_UNBLOCK_THREADS;

[Darsey Litzenberger (dlitz)]

Found the offending code in rabinMillerTest:

        Py_BEGIN_ALLOW_THREADS;
        if ((mpz_tstbit (n, 0) == 0) || (mpz_cmp_ui (n, 3) < 0))
                return (mpz_cmp_ui (n, 2) == 0);

[Darsey Litzenberger (dlitz)]

Fixed: https://github.com/dlitz/pycrypto/commit/88b4a886ccffef2f6cdbd20f8c983eb5ded1c813

[Darsey Litzenberger (dlitz)]

Fixed in PyCrypto 2.6.