I was looking inside and build ncrypt-0.6.4 from sources.
In the code (inside fromPEM_PublicKey) I put marker and found that this function was finished successfully.
But SegFault - still happens.

Here is a full backtrace:


veselin@dell64:~$ gdb python
GNU gdb (Ubuntu/Linaro 7.2-1ubuntu11) 7.2
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/bin/python...Reading symbols from /usr/lib/debug/usr/bin/python2.7...done.
done.
(gdb) run testncrypt.py 
Starting program: /usr/bin/python testncrypt.py
[Thread debugging using libthread_db enabled]
1
2
3
4
5
6
7
8

Program received signal SIGSEGV, Segmentation fault.
PyEval_EvalFrameEx (f=<value optimized out>, throwflag=<value optimized out>) at ../Python/ceval.c:1067
1067	../Python/ceval.c: Нет такого файла или каталога.
	in ../Python/ceval.c
(gdb) bt
#0  PyEval_EvalFrameEx (f=<value optimized out>, throwflag=<value optimized out>) at ../Python/ceval.c:1067
#1  0x000000000049d325 in PyEval_EvalCodeEx (co=0x9b48b0, globals=<value optimized out>, locals=<value optimized out>, 
    args=<value optimized out>, argcount=<value optimized out>, kws=<value optimized out>, kwcount=0, defs=0x0, defcount=0, closure=0x0)
    at ../Python/ceval.c:3253
#2  0x00000000004ecb02 in PyEval_EvalCode (co=<value optimized out>, globals=<value optimized out>, locals=<value optimized out>)
    at ../Python/ceval.c:667
#3  0x00000000004fdc74 in run_mod (mod=<value optimized out>, filename=<value optimized out>, globals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, locals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, 
    flags=<value optimized out>, arena=<value optimized out>) at ../Python/pythonrun.c:1346
#4  0x000000000042c182 in PyRun_FileExFlags (fp=0xa5e1f0, filename=0x7fffffffe56d "testncrypt.py", start=<value optimized out>, globals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, locals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, closeit=1, flags=
    0x7fffffffe150) at ../Python/pythonrun.c:1332
#5  0x000000000042cb4a in PyRun_SimpleFileExFlags (fp=0xa5e1f0, filename=<value optimized out>, closeit=1, flags=0x7fffffffe150)
    at ../Python/pythonrun.c:936
#6  0x0000000000418c9e in Py_Main (argc=<value optimized out>, argv=0x7fffffffe278) at ../Modules/main.c:599
#7  0x00007ffff69c2eff in __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
#8  0x00000000004c62b1 in _start ()
(gdb) 
#0  PyEval_EvalFrameEx (f=<value optimized out>, throwflag=<value optimized out>) at ../Python/ceval.c:1067
#1  0x000000000049d325 in PyEval_EvalCodeEx (co=0x9b48b0, globals=<value optimized out>, locals=<value optimized out>, 
    args=<value optimized out>, argcount=<value optimized out>, kws=<value optimized out>, kwcount=0, defs=0x0, defcount=0, closure=0x0)
    at ../Python/ceval.c:3253
#2  0x00000000004ecb02 in PyEval_EvalCode (co=<value optimized out>, globals=<value optimized out>, locals=<value optimized out>)
    at ../Python/ceval.c:667
#3  0x00000000004fdc74 in run_mod (mod=<value optimized out>, filename=<value optimized out>, globals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, locals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, 
    flags=<value optimized out>, arena=<value optimized out>) at ../Python/pythonrun.c:1346
#4  0x000000000042c182 in PyRun_FileExFlags (fp=0xa5e1f0, filename=0x7fffffffe56d "testncrypt.py", start=<value optimized out>, globals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, locals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, closeit=1, flags=
    0x7fffffffe150) at ../Python/pythonrun.c:1332
#5  0x000000000042cb4a in PyRun_SimpleFileExFlags (fp=0xa5e1f0, filename=<value optimized out>, closeit=1, flags=0x7fffffffe150)
    at ../Python/pythonrun.c:936
#6  0x0000000000418c9e in Py_Main (argc=<value optimized out>, argv=0x7fffffffe278) at ../Modules/main.c:599
#7  0x00007ffff69c2eff in __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
#8  0x00000000004c62b1 in _start ()
(gdb) 
#0  PyEval_EvalFrameEx (f=<value optimized out>, throwflag=<value optimized out>) at ../Python/ceval.c:1067
#1  0x000000000049d325 in PyEval_EvalCodeEx (co=0x9b48b0, globals=<value optimized out>, locals=<value optimized out>, 
    args=<value optimized out>, argcount=<value optimized out>, kws=<value optimized out>, kwcount=0, defs=0x0, defcount=0, closure=0x0)
    at ../Python/ceval.c:3253
#2  0x00000000004ecb02 in PyEval_EvalCode (co=<value optimized out>, globals=<value optimized out>, locals=<value optimized out>)
    at ../Python/ceval.c:667
#3  0x00000000004fdc74 in run_mod (mod=<value optimized out>, filename=<value optimized out>, globals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, locals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, 
    flags=<value optimized out>, arena=<value optimized out>) at ../Python/pythonrun.c:1346
#4  0x000000000042c182 in PyRun_FileExFlags (fp=0xa5e1f0, filename=0x7fffffffe56d "testncrypt.py", start=<value optimized out>, globals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, locals=
    {'keysrc': '\n-----BEGIN RSA PUBLIC KEY-----\nMIIBCAKCAQEA7GlbcsySk8cgHfzx7BmGnF+WWrwFRpMJN26u9BsAL0eETEeQsQXE\ngDeKrUHMs5EKtBBRuJlHKy0uxqK0M/KyAfBw7a6HhNQwT2/2dXhylUre1coCHeIv\nKBkV1WJxNnjCJwKrWY0y5geKczPnRoAYJFqNZE1XzyYOqYmVoCs6XB5yPw2nOfcV\nTX5fXYPzsnA9EaR+l2GKbmwIJXGZTW4kl1P6VCjrtlEL5B1qyOd3JYUm8JRJihca\n8LIQrNu00awnxAkUQS0ucp5MHaI0jFK79sgkDujdAWtPL7A/CK97WUMNl9JhAvV/\noN9GFZO5MuNwUcfu1Nqf8Xj18lT1g9bH5wIBBQ==\n-----END RSA PUBLIC KEY-----\n', '__builtins__': <module at remote 0x7ffff7f95ad0>, '__file__': 'testncrypt.py', 'RSAKey': <type at remote 0x7ffff61f3900>, '__package__': None, '__name__': '__main__', '__doc__': None, 'k': <ncrypt_rsa.RSAKey at remote 0x8e9430>}, closeit=1, flags=
    0x7fffffffe150) at ../Python/pythonrun.c:1332
#5  0x000000000042cb4a in PyRun_SimpleFileExFlags (fp=0xa5e1f0, filename=<value optimized out>, closeit=1, flags=0x7fffffffe150)
    at ../Python/pythonrun.c:936
#6  0x0000000000418c9e in Py_Main (argc=<value optimized out>, argv=0x7fffffffe278) at ../Modules/main.c:599
#7  0x00007ffff69c2eff in __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
#8  0x00000000004c62b1 in _start ()
(gdb)  
(gdb) 
(gdb) 
(gdb)