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Querying active SIP status directly from the kernel, bypassing nvram and csrutil, via python on macOS
# An overly complicated SIP config checker
# This is a technically interesting implementation because it does not rely on csrutil
# Instead it queries the kernel directly for the current configuration status
# This means, for example, in environments where SIP has been disabled and csrutil has
# been removed or modified (say, with DYLD_LIBRARY_PATH), as long as python can run you
# can still check status
# Additionally, checking the nvram csr-active-config setting isn't accurate now with
# 10.12.2+, since running "sudo csrutil clear" deletes the variable until reboot,
# leaving only the kernel itself understanding the current SIP state
# Examples of usage at the bottom
from ctypes import CDLL, c_uint, byref
# from xnu/bsd/sys/csr.h
CSR_VALID_FLAGS = [
('CSR_ALLOW_UNTRUSTED_KEXTS', 'kext', '', 'Kext Signing', 1 << 0),
('CSR_ALLOW_UNRESTRICTED_FS', 'fs', '', 'Filesystem Protection', 1 << 1),
('CSR_ALLOW_TASK_FOR_PID', 'debug', '', 'Debugging Restrictions', 1 << 2),
('CSR_ALLOW_KERNEL_DEBUGGER', '', '', '<<CSR_ALLOW_KERNEL_DEBUGGER>>', 1 << 3),
('CSR_ALLOW_APPLE_INTERNAL', '', '--no-internal', 'Apple Internal', 1 << 4),
('CSR_ALLOW_UNRESTRICTED_DTRACE', 'dtrace', '', 'DTrace Restrictions', 1 << 5),
('CSR_ALLOW_UNRESTRICTED_NVRAM', 'nvram', '', 'NVRAM Protections', 1 << 6),
('CSR_ALLOW_DEVICE_CONFIGURATION', '', '', '<<CSR_ALLOW_DEVICE_CONFIGURATION>>', 1 << 7),
('CSR_ALLOW_ANY_RECOVERY_OS', 'basesystem', '', 'BaseSystem Verification', 1 << 8),
]
SIP_DISABLED = (1 << 0) | (1 << 1) | (1 << 2) | (1 << 5) | (1 << 6)
class SIPSetting(object):
def __init__(self, sip_flag_info, status=True):
super(SIPSetting, self).__init__()
self.define = sip_flag_info[0]
self.without = sip_flag_info[1]
self.force_off = sip_flag_info[2]
self.description = sip_flag_info[3]
self.bitmask = sip_flag_info[4]
self.disabled = status
@property
def enabled(self):
return not self.disabled
def __str__(self):
if self.disabled is True:
status = "disabled"
else:
status = "enabled"
return "%s: %s" % (self.description, status)
def __repr__(self):
return self.__str__()
def __nonzero__(self):
return self.disabled
def __eq__(self, value):
return self.disabled == value
class SIPConfig(object):
def __init__(self):
super(SIPConfig, self).__init__()
libsys = CDLL('/usr/lib/libSystem.dylib')
raw = c_uint(0)
errmsg = libsys.csr_get_active_config(byref(raw))
self.csr_active_config = raw.value
self.csr_bitmask_str = "{0:b}".format(raw.value).zfill(16)
self.key_order = [x[0] for x in CSR_VALID_FLAGS]
self.config_dict = dict()
self.full_config = list()
self.enabled_config = list()
for i in CSR_VALID_FLAGS:
k, n, d, s, b = i
# determine if this flag is set
if (b & self.csr_active_config):
s_obj = SIPSetting(i, status=True)
self.enabled_config.append(s_obj)
else:
s_obj = SIPSetting(i, status=False)
self.full_config.append(s_obj)
self.config_dict[s_obj.define] = s_obj
if (s_obj.without != ''):
self.config_dict[s_obj.without] = s_obj
@property
def disabled(self):
if ((self.csr_active_config & SIP_DISABLED) == SIP_DISABLED):
return True
return False
@property
def enabled(self):
return not self.disabled
@property
def status(self):
if self.enabled:
return 'enabled'
else:
return 'disabled'
def __getattr__(self, attr):
return self.config_dict.__getitem__(attr)
def __getitem__(self, item):
if isinstance(item, (int, long, list, slice)):
return self.enabled_config.__getitem__(item)
else:
return self.config_dict[item]
def __repr__(self):
return self.enabled_config.__repr__()
# Example usages:
# ---------------
# >>> sip = SIPConfig()
# >>> sip.status
# 'enabled'
# >>> sip.enabled
# True
# >>> sip.disabled
# False
# >>> sip
# [Debugging Restrictions: disabled, DTrace Restrictions: disabled]
# This is a custom configuration with dtrace and debug disabled
# Lots of different ways to reference the settings
# >>> sip.fs
# Filesystem Protection: enabled
# >>> sip['fs']
# Filesystem Protection: enabled
# >>> sip.fs.enabled
# True
# >>> sip.fs.disabled
# False
# >>> sip['CSR_ALLOW_UNTRUSTED_KEXTS']
# Kext Signing: enabled
# >>> sip.CSR_ALLOW_UNTRUSTED_KEXTS
# Kext Signing: enabled
# >>> sip.kext
# Kext Signing: enabled
# >>> sip.kext.define
# 'CSR_ALLOW_UNTRUSTED_KEXTS'
# >>> sip.kext.without
# 'kext'
# >>> sip.kext.description
# 'Kext Signing'
# >>> sip.kext.bitmask
# 1
# >>> sip.kext.disabled
# False
# Individual attributes boolean evaluate to "is the protection disabled"
# example: Is the filesystem protection disabled?
# >>> 'fs protection is disabled' if sip.fs else 'fs protection is enabled'
# 'fs protection is enabled'
# If you want to see all of the settings
# >>> sip.full_config
# [Kext Signing: enabled, Filesystem Protection: enabled, Debugging Restrictions: disabled, <<CSR_ALLOW_KERNEL_DEBUGGER>>: enabled, Apple Internal: enabled, DTrace Restrictions: disabled, NVRAM Protections: enabled, <<CSR_ALLOW_DEVICE_CONFIGURATION>>: enabled, BaseSystem Verification: enabled]
# >>> sip.csr_active_config
# 36L
# >>> sip.csr_bitmask_str
# '0000000000100100'
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