This file is indexed.

/usr/share/pyshared/pam.py is in python-pampy 0.1.4-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
# (c) 2007 Chris AtLee <chris@atlee.ca>
# Licensed under the MIT license:
# http://www.opensource.org/licenses/mit-license.php
"""
PAM module for python

Provides an authenticate function that will allow the caller to authenticate
a user against the Pluggable Authentication Modules (PAM) on the system.

Implemented using ctypes, so no compilation is necessary.
"""
__all__ = ['authenticate']

from ctypes import CDLL, POINTER, Structure, CFUNCTYPE, cast, pointer, sizeof
from ctypes import c_void_p, c_uint, c_char_p, c_char, c_int
from ctypes.util import find_library

LIBPAM = CDLL(find_library("pam"))
LIBC = CDLL(find_library("c"))

CALLOC = LIBC.calloc
CALLOC.restype = c_void_p
CALLOC.argtypes = [c_uint, c_uint]

STRDUP = LIBC.strdup
STRDUP.argstypes = [c_char_p]
STRDUP.restype = POINTER(c_char) # NOT c_char_p !!!!

# Various constants
PAM_PROMPT_ECHO_OFF = 1
PAM_PROMPT_ECHO_ON = 2
PAM_ERROR_MSG = 3
PAM_TEXT_INFO = 4

class PamHandle(Structure):
    """wrapper class for pam_handle_t"""
    _fields_ = [
            ("handle", c_void_p)
            ]

    def __init__(self):
        Structure.__init__(self)
        self.handle = 0

class PamMessage(Structure):
    """wrapper class for pam_message structure"""
    _fields_ = [
            ("msg_style", c_int),
            ("msg", POINTER(c_char)),
            ]

    def __repr__(self):
        return "<PamMessage %i '%s'>" % (self.msg_style, self.msg)

class PamResponse(Structure):
    """wrapper class for pam_response structure"""
    _fields_ = [
            ("resp", POINTER(c_char)),
            ("resp_retcode", c_int),
            ]

    def __repr__(self):
        return "<PamResponse %i '%s'>" % (self.resp_retcode, self.resp)

CONV_FUNC = CFUNCTYPE(c_int,
        c_int, POINTER(POINTER(PamMessage)),
               POINTER(POINTER(PamResponse)), c_void_p)

class PamConv(Structure):
    """wrapper class for pam_conv structure"""
    _fields_ = [
            ("conv", CONV_FUNC),
            ("appdata_ptr", c_void_p)
            ]

PAM_START = LIBPAM.pam_start
PAM_START.restype = c_int
PAM_START.argtypes = [c_char_p, c_char_p, POINTER(PamConv),
        POINTER(PamHandle)]

PAM_END = LIBPAM.pam_end
PAM_END.restpe = c_int
PAM_END.argtypes = [PamHandle, c_int]

PAM_AUTHENTICATE = LIBPAM.pam_authenticate
PAM_AUTHENTICATE.restype = c_int
PAM_AUTHENTICATE.argtypes = [PamHandle, c_int]

def authenticate(username, password, service='login'):
    """Returns True if the given username and password authenticate for the
    given service.  Returns False otherwise
    
    ``username``: the username to authenticate
    
    ``password``: the password in plain text
    
    ``service``: the PAM service to authenticate against.
                 Defaults to 'login'"""
    @CONV_FUNC
    def my_conv(n_messages, messages, p_response, app_data):
        """Simple conversation function that responds to any
        prompt where the echo is off with the supplied password"""
        # Create an array of n_messages response objects
        addr = CALLOC(n_messages, sizeof(PamResponse))
        p_response[0] = cast(addr, POINTER(PamResponse))
        for i in range(n_messages):
            if messages[i].contents.msg_style == PAM_PROMPT_ECHO_OFF:
                pw_copy = STRDUP(str(password))
                p_response.contents[i].resp = pw_copy
                p_response.contents[i].resp_retcode = 0
        return 0

    handle = PamHandle()
    conv = PamConv(my_conv, 0)
    retval = PAM_START(service, username, pointer(conv), pointer(handle))

    if retval != 0:
        # TODO: This is not an authentication error, something
        # has gone wrong starting up PAM
        PAM_END(handle, retval)
        return False

    retval = PAM_AUTHENTICATE(handle, 0)
    e = PAM_END(handle, retval)
    return retval == 0 and e == 0

if __name__ == "__main__":
    import getpass
    print authenticate(getpass.getuser(), getpass.getpass())