from Screens.Screen import Screen
from Plugins.Plugin import PluginDescriptor
from enigma import eTPM
import sha

def bin2long(s):
	return reduce( lambda x,y:(x<<8L)+y, map(ord, s))

def long2bin(l):
	res = ""
	for byte in range(128):
		res += chr((l >> (1024 - (byte + 1) * 8)) & 0xff)
	return res

def rsa_pub1024(src, mod):
	return long2bin(pow(bin2long(src), 65537, bin2long(mod)))
	
def decrypt_block(src, mod):
	if len(src) != 128 and len(src) != 202:
		return None
	dest = rsa_pub1024(src[:128], mod)
	hash = sha.new(dest[1:107])
	if len(src) == 202:
		hash.update(src[131:192])	
	result = hash.digest()
	if result == dest[107:127]:
		return dest
	return None

def validate_cert(cert, key):
	buf = decrypt_block(cert[8:], key) 
	if buf is None:
		return None
	return buf[36:107] + cert[139:196]

def read_random():
	try:
		fd = open("/dev/urandom", "r")
		buf = fd.read(8)
		fd.close()
		return buf
	except:
		return None

def main(session, **kwargs):
	try:
		device = open("/proc/stb/info/model", "r").readline().strip()
	except:
		device = ""	
	if device != "dm7025":
		rootkey = ['\x9f', '|', '\xe4', 'G', '\xc9', '\xb4', '\xf4', '#', '&', '\xce', '\xb3', '\xfe', '\xda', '\xc9', 'U', '`', '\xd8', '\x8c', 's', 'o', '\x90', '\x9b', '\\', 'b', '\xc0', '\x89', '\xd1', '\x8c', '\x9e', 'J', 'T', '\xc5', 'X', '\xa1', '\xb8', '\x13', '5', 'E', '\x02', '\xc9', '\xb2', '\xe6', 't', '\x89', '\xde', '\xcd', '\x9d', '\x11', '\xdd', '\xc7', '\xf4', '\xe4', '\xe4', '\xbc', '\xdb', '\x9c', '\xea', '}', '\xad', '\xda', 't', 'r', '\x9b', '\xdc', '\xbc', '\x18', '3', '\xe7', '\xaf', '|', '\xae', '\x0c', '\xe3', '\xb5', '\x84', '\x8d', '\r', '\x8d', '\x9d', '2', '\xd0', '\xce', '\xd5', 'q', '\t', '\x84', 'c', '\xa8', ')', '\x99', '\xdc', '<', '"', 'x', '\xe8', '\x87', '\x8f', '\x02', ';', 'S', 'm', '\xd5', '\xf0', '\xa3', '_', '\xb7', 'T', '\t', '\xde', '\xa7', '\xf1', '\xc9', '\xae', '\x8a', '\xd7', '\xd2', '\xcf', '\xb2', '.', '\x13', '\xfb', '\xac', 'j', '\xdf', '\xb1', '\x1d', ':', '?']
		
		etpm = eTPM()
		l2cert = etpm.getCert(eTPM.TPMD_DT_LEVEL2_CERT)
		if l2cert is None:
			print "l2cert not found"
			return
	
		l2key = validate_cert(l2cert, rootkey)
		if l2key is None:
			print "l2cert invalid"
			return
		
		l3cert = etpm.getCert(eTPM.TPMD_DT_LEVEL3_CERT)
		if l3cert is None:
			print "l3cert not found (can be fixed by running the genuine dreambox plugin and running the offered update)"
			return
		
		l3key = validate_cert(l3cert, l2key)
		if l3key is None:
			print "l3cert invalid"
			return
		
		rnd = read_random()
		if rnd is None:
			print "random error"
			return
		val = etpm.challenge(rnd)
		result = decrypt_block(val, l3key)
	if device == "dm7025" or result[80:88] == rnd:
		print "successfully finished the tpm test"
			# would start your plugin here

def Plugins(**kwargs):
	return [PluginDescriptor(name = "TPM Demo", description = _("A demo plugin for TPM usage."), where = PluginDescriptor.WHERE_EXTENSIONSMENU, fnc = main),
		PluginDescriptor(name = "TPM Demo", description = _("A demo plugin for TPM usage."), icon = "plugin.png", where = PluginDescriptor.WHERE_PLUGINMENU, fnc = main)]