def mutual_authenticate(self, p1, p2, mutual_challenge):
"""
Takes an encrypted challenge in the form
'Terminal Challenge | Card Challenge | Card number'
and checks it for validity. If the challenge is successful
the card encrypts 'Card Challenge | Terminal challenge' and
returns this value
"""
key = self._get_referenced_key(p1, p2)
card_number = self.get_card_number()
if (key == None):
raise SwError(SW["ERR_INCORRECTP1P2"])
if p1 == 0x00: #No information given
cipher = get_referenced_cipher(self.cipher)
else:
cipher = get_referenced_cipher(p1)
if (cipher == None):
raise SwError(SW["ERR_INCORRECTP1P2"])
plain = vsCrypto.decrypt(cipher, key, mutual_challenge)
last_challenge_len = len(self.last_challenge)
terminal_challenge = plain[:last_challenge_len - 1]
card_challenge = plain[last_challenge_len:-len(card_number) - 1]
serial_number = plain[-len(card_number):]
if terminal_challenge != self.last_challenge:
raise SwError(SW["WARN_NOINFO63"])
elif serial_number != card_number:
raise SwError(SW["WARN_NOINFO63"])
result = card_challenge + terminal_challenge
return SW["NORMAL"], vsCrypto.encrypt(cipher, key, result)
def mutual_authenticate(self, p1, p2, mutual_challenge):
"""
Takes an encrypted challenge in the form
'Terminal Challenge | Card Challenge | Card number'
and checks it for validity. If the challenge is successful
the card encrypts 'Card Challenge | Terminal challenge' and
returns this value
"""
key = self._get_referenced_key(p1, p2)
card_number = self.get_card_number()
if (key == None):
raise SwError(SW["ERR_INCORRECTP1P2"])
if p1 == 0x00: #No information given
cipher = get_referenced_cipher(self.cipher)
else:
cipher = get_referenced_cipher(p1)
if (cipher == None):
raise SwError(SW["ERR_INCORRECTP1P2"])
plain = vsCrypto.decrypt(cipher, key, mutual_challenge)
last_challenge_len = len(self.last_challenge)
terminal_challenge = plain[:last_challenge_len-1]
card_challenge = plain[last_challenge_len:-len(card_number)-1]
serial_number = plain[-len(card_number):]
if terminal_challenge != self.last_challenge:
raise SwError(SW["WARN_NOINFO63"])
elif serial_number != card_number:
raise SwError(SW["WARN_NOINFO63"])
result = card_challenge + terminal_challenge
return SW["NORMAL"], vsCrypto.encrypt(cipher, key, result)
def encipher(self, p1, p2, data):
"""
Encipher data using key, algorithm, IV and Padding specified
by the current Security environment.
:returns: raw data (no TLV coding).
"""
algo = self.ct.algorithm
key = self.ct.key
if key == None or algo == None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
else:
padded = vsCrypto.append_padding(vsCrypto.get_cipher_blocklen(algo), data)
crypted = vsCrypto.encrypt(algo, key, padded, self.ct.iv)
return crypted
def encipher(self, p1, p2, data):
"""
Encipher data using key, algorithm, IV and Padding specified
by the current Security environment.
:returns: raw data (no TLV coding).
"""
algo = self.ct.algorithm
key = self.ct.key
if key == None or algo == None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
else:
padded = vsCrypto.append_padding(vsCrypto.get_cipher_blocklen(algo), data)
crypted = vsCrypto.encrypt(algo, key, padded, self.ct.iv)
return crypted
def verify_cryptographic_checksum(self, p1, p2, data):
"""
Verify the cryptographic checksum contained in the data field.
Data field must contain a cryptographic checksum (tag 0x8E) and a plain
value (tag 0x80)
"""
plain = ""
cct = ""
algo = self.cct.algorithm
key = self.cct.key
iv = self.cct.iv
if algo == None or key == None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
structure = unpack(data)
for tag, length, value in structure:
if tag == 0x80:
plain = value
elif tag == 0x8E:
cct = value
if plain == "" or cct == "":
raise SwError(SW["ERR_SECMESSOBJECTSMISSING"])
else:
my_cct = vsCrypto.crypto_checksum(algo, key, plain, iv)
if my_cct == cct:
return ""
else:
raise SwError["ERR_SECMESSOBJECTSINCORRECT"]
def __init__(self, PIN, cardNumber, mf=None, cardSecret=None, default_se=Security_Environment):
self.PIN = PIN
self.mf = mf
self.cardNumber = cardNumber
self.last_challenge = None #Will contain non-readable binary string
self.counter = 3 #Number of tries for PIN validation
self.cipher = 0x01
self.asym_key = None
keylen = vsCrypto.get_cipher_keylen(get_referenced_cipher(self.cipher))
if cardSecret is None: #Generate a random card secret
self.cardSecret = urandom(keylen)
else:
if len(cardSecret) != keylen:
raise ValueError("cardSecret has the wrong key length for: " +\
get_referenced_cipher(self.cipher))
else:
self.cardSecret = cardSecret
#Security Environments may be saved to/retrieved from this dictionary
self.saved_SEs = {}
self.default_se = default_se
self.current_SE = default_se(self.mf, self)
def verify_cryptographic_checksum(self, p1, p2, data):
"""
Verify the cryptographic checksum contained in the data field.
Data field must contain a cryptographic checksum (tag 0x8E) and a plain
value (tag 0x80)
"""
plain = ""
cct = ""
algo = self.cct.algorithm
key = self.cct.key
iv = self.cct.iv
if algo == None or key == None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
structure = unpack(data)
for tag, length, value in structure:
if tag == 0x80:
plain = value
elif tag == 0x8E:
cct = value
if plain == "" or cct == "":
raise SwError(SW["ERR_SECMESSOBJECTSMISSING"])
else:
my_cct = vsCrypto.crypto_checksum(algo, key, plain, iv)
if my_cct == cct:
return ""
else:
raise SwError["ERR_SECMESSOBJECTSINCORRECT"]
def __init__(self,
PIN,
cardNumber,
mf=None,
cardSecret=None,
default_se=Security_Environment):
self.PIN = PIN
self.mf = mf
self.cardNumber = cardNumber
self.last_challenge = None #Will contain non-readable binary string
self.counter = 3 #Number of tries for PIN validation
self.cipher = 0x01
self.asym_key = None
keylen = vsCrypto.get_cipher_keylen(get_referenced_cipher(self.cipher))
if cardSecret is None: #Generate a random card secret
self.cardSecret = urandom(keylen)
else:
if len(cardSecret) != keylen:
raise ValueError("cardSecret has the wrong key length for: " +\
get_referenced_cipher(self.cipher))
else:
self.cardSecret = cardSecret
#Security Environments may be saved to/retrieved from this dictionary
self.saved_SEs = {}
self.default_se = default_se
self.current_SE = default_se(self.mf, self)
def encipher(self, p1, p2, data):
padded = vsCrypto.append_padding(self.cct.blocklength, data)
cipher = eac.EAC_encrypt(self.eac_ctx, padded)
if not cipher:
eac.print_ossl_err()
raise SwError(SW["ERR_NOINFO69"])
return cipher
def encipher(self, p1, p2, data):
padded = vsCrypto.append_padding(self.cct.blocklength, data)
cipher = eac.EAC_encrypt(self.eac_ctx, padded)
if not cipher:
eac.print_ossl_err()
raise SwError(SW["ERR_NOINFO69"])
return cipher
def external_authenticate(self, p1, p2, resp_data):
"""Performs the basic access control protocol as defined in
the ICAO MRTD standard"""
rnd_icc = self.last_challenge
# Receive Mutual Authenticate APDU from terminal
# Decrypt data and check MAC
Eifd = resp_data[:-8]
padded_Eifd = vsCrypto.append_padding(self.current_SE.cct.blocklength,
Eifd)
Mifd = vsCrypto.crypto_checksum("CC", self.KMac, padded_Eifd)
# Check the MAC
if not Mifd == resp_data[-8:]:
raise SwError(SW["ERR_SECMESSOBJECTSINCORRECT"])
# Decrypt the data
plain = vsCrypto.decrypt("DES3-CBC", self.KEnc, resp_data[:-8])
if plain[8:16] != rnd_icc:
raise SwError(SW["WARN_NOINFO63"])
# Extract keying material from IFD, generate ICC keying material
Kifd = plain[16:]
rnd_ifd = plain[:8]
Kicc = urandom(16)
# Generate Answer
data = plain[8:16] + plain[:8] + Kicc
Eicc = vsCrypto.encrypt("DES3-CBC", self.KEnc, data)
padded_Eicc = vsCrypto.append_padding(self.current_SE.cct.blocklength,
Eicc)
Micc = vsCrypto.crypto_checksum("CC", self.KMac, padded_Eicc)
# Derive the final keys and set the current SE
KSseed = vsCrypto.operation_on_string(Kicc, Kifd, lambda a, b: a ^ b)
self.current_SE.ct.key = self.derive_key(KSseed, 1)
self.current_SE.cct.key = self.derive_key(KSseed, 2)
self.current_SE.ssc = stringtoint(rnd_icc[-4:] + rnd_ifd[-4:])
return SW["NORMAL"], Eicc + Micc
def compute_cryptographic_checksum(self, p1, p2, data):
"""
Compute a cryptographic checksum (e.g. MAC) for the given data.
Algorithm and key are specified in the current SE
"""
if p1 != 0x8E or p2 != 0x80:
raise SwError(SW["ERR_INCORRECTP1P2"])
if self.cct.key is None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
checksum = vsCrypto.crypto_checksum(self.cct.algorithm, self.cct.key, data, self.cct.iv)
return checksum
def external_authenticate(self, p1, p2, data):
"""
Authenticate the terminal to the card. Check whether Terminal correctly
encrypted the given challenge or not
"""
if self.last_challenge is None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
key = self._get_referenced_key(p1, p2)
if p1 == 0x00: #No information given
cipher = get_referenced_cipher(self.cipher)
else:
cipher = get_referenced_cipher(p1)
reference = vsCrypto.append_padding(cipher, self.last_challenge)
reference = vsCrypto.encrypt(cipher, key, reference)
if(reference == data):
#Invalidate last challenge
self.last_challenge = None
return SW["NORMAL"], ""
else:
raise SwError(SW["WARN_NOINFO63"])
def compute_cryptographic_checksum(self, p1, p2, data):
"""
Compute a cryptographic checksum (e.g. MAC) for the given data.
The ePass uses a Send Sequence Counter for MAC calculation
"""
if p1 != 0x8E or p2 != 0x80:
raise SwError(SW["ERR_INCORRECTP1P2"])
self.ssc += 1
checksum = vsCrypto.crypto_checksum(self.cct.algorithm, self.cct.key,
data, self.cct.iv, self.ssc)
return checksum
def compute_cryptographic_checksum(self, p1, p2, data):
"""
Compute a cryptographic checksum (e.g. MAC) for the given data.
Algorithm and key are specified in the current SE
"""
if p1 != 0x8E or p2 != 0x80:
raise SwError(SW["ERR_INCORRECTP1P2"])
if self.cct.key == None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
checksum = vsCrypto.crypto_checksum(self.cct.algorithm, self.cct.key,
data, self.cct.iv)
return checksum
def external_authenticate(self, p1, p2, data):
"""
Authenticate the terminal to the card. Check whether Terminal correctly
encrypted the given challenge or not
"""
if self.last_challenge is None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
key = self._get_referenced_key(p1, p2)
if p1 == 0x00: #No information given
cipher = get_referenced_cipher(self.cipher)
else:
cipher = get_referenced_cipher(p1)
reference = vsCrypto.append_padding(cipher, self.last_challenge)
reference = vsCrypto.encrypt(cipher, key, reference)
if(reference == data):
#Invalidate last challenge
self.last_challenge = None
return SW["NORMAL"], ""
else:
raise SwError(SW["WARN_NOINFO63"])
def decipher(self, p1, p2, data):
"""
Decipher data using key, algorithm, IV and Padding specified
by the current Security environment.
:returns: raw data (no TLV coding). Padding is not removed!!!
"""
algo = self.ct.algorithm
key = self.ct.key
if key == None or algo == None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
else:
plain = vsCrypto.decrypt(algo, key, data, self.ct.iv)
return plain
def decipher(self, p1, p2, data):
"""
Decipher data using key, algorithm, IV and Padding specified
by the current Security environment.
:returns: raw data (no TLV coding). Padding is not removed!!!
"""
algo = self.ct.algorithm
key = self.ct.key
if key == None or algo == None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
else:
plain = vsCrypto.decrypt(algo, key, data, self.ct.iv)
return plain
def hash(self, p1, p2, data):
"""
Hash the given data using the algorithm specified by the current
Security environment.
:return: raw data (no TLV coding).
"""
if p1 != 0x90 or not p2 in (0x80, 0xA0):
raise SwError(SW["ERR_INCORRECTP1P2"])
algo = self.ht.algorithm
if algo == None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
try:
hash = vsCrypto.hash(algo, data)
except ValueError:
raise SwError(SW["ERR_EXECUTION"])
return hash
def hash(self, p1, p2, data):
"""
Hash the given data using the algorithm specified by the current
Security environment.
:return: raw data (no TLV coding).
"""
if p1 != 0x90 or not p2 in (0x80, 0xA0):
raise SwError(SW["ERR_INCORRECTP1P2"])
algo = self.ht.algorithm
if algo == None:
raise SwError(SW["ERR_CONDITIONNOTSATISFIED"])
try:
hash = vsCrypto.hash(algo, data)
except ValueError:
raise SwError(SW["ERR_EXECUTION"])
return hash
def protect_response(self, sw, result):
"""
This method protects a response APDU using secure messaging mechanisms
:returns: the protected data and the SW bytes
"""
return_data = ""
# if sw == SW["NORMAL"]:
# sw = inttostring(sw)
# length = len(sw)
# tag = SM_Class["PLAIN_PROCESSING_STATUS"]
# tlv_sw = pack([(tag,length,sw)])
# return_data += tlv_sw
if result != "": # Encrypt the data included in the RAPDU
encrypted = self.encipher(0x82, 0x80, result)
encrypted = "\x01" + encrypted
encrypted_tlv = pack([(
SM_Class["CRYPTOGRAM_PADDING_INDICATOR_ODD"],
len(encrypted),
encrypted)])
return_data += encrypted_tlv
if sw == SW["NORMAL"]:
if self.cct.algorithm is None:
raise SwError(SW["CONDITIONSNOTSATISFIED"])
elif self.cct.algorithm == "CC":
tag = SM_Class["CHECKSUM"]
padded = vsCrypto.append_padding(self.cct.blocklength,
return_data)
auth = self.compute_cryptographic_checksum(0x8E, 0x80, padded)
length = len(auth)
return_data += pack([(tag, length, auth)])
elif self.cct.algorithm == "SIGNATURE":
tag = SM_Class["DIGITAL_SIGNATURE"]
hash = self.hash(0x90, 0x80, return_data)
auth = self.compute_digital_signature(0x9E, 0x9A, hash)
length = len(auth)
return_data += pack([(tag, length, auth)])
return sw, return_data
def protect_response(self, sw, result):
"""
This method protects a response APDU using secure messaging mechanisms
:returns: the protected data and the SW bytes
"""
return_data = ""
#if sw == SW["NORMAL"]:
# sw = inttostring(sw)
# length = len(sw)
# tag = SM_Class["PLAIN_PROCESSING_STATUS"]
# tlv_sw = pack([(tag,length,sw)])
# return_data += tlv_sw
if result != "": # Encrypt the data included in the RAPDU
encrypted = self.encipher(0x82, 0x80, result)
encrypted = "\x01" + encrypted
encrypted_tlv = pack([
(SM_Class["CRYPTOGRAM_PADDING_INDICATOR_ODD"], len(encrypted),
encrypted)
])
return_data += encrypted_tlv
if sw == SW["NORMAL"]:
if self.cct.algorithm == None:
raise SwError(SW["CONDITIONSNOTSATISFIED"])
elif self.cct.algorithm == "CC":
tag = SM_Class["CHECKSUM"]
padded = vsCrypto.append_padding(self.cct.blocklength,
return_data)
auth = self.compute_cryptographic_checksum(0x8E, 0x80, padded)
length = len(auth)
return_data += pack([(tag, length, auth)])
elif self.cct.algorithm == "SIGNATURE":
tag = SM_Class["DIGITAL_SIGNATURE"]
hash = self.hash(0x90, 0x80, return_data)
auth = self.compute_digital_signature(0x9E, 0x9A, hash)
length = len(auth)
return_data += pack([(tag, length, auth)])
return sw, return_data
def internal_authenticate(self, p1, p2, data):
"""
Authenticate card to terminal. Encrypt the challenge of the terminal
to prove key posession
"""
if p1 == 0x00: #No information given
cipher = get_referenced_cipher(self.cipher)
else:
cipher = get_referenced_cipher(p1)
if cipher == "RSA" or cipher == "DSA":
crypted_challenge = self.asym_key.sign(data,"")
crypted_challenge = crypted_challenge[0]
crypted_challenge = inttostring(crypted_challenge)
else:
key = self._get_referenced_key(p1, p2)
crypted_challenge = vsCrypto.encrypt(cipher, key, data)
return SW["NORMAL"], crypted_challenge
def internal_authenticate(self, p1, p2, data):
"""
Authenticate card to terminal. Encrypt the challenge of the terminal
to prove key posession
"""
if p1 == 0x00: #No information given
cipher = get_referenced_cipher(self.cipher)
else:
cipher = get_referenced_cipher(p1)
if cipher == "RSA" or cipher == "DSA":
crypted_challenge = self.asym_key.sign(data, "")
crypted_challenge = crypted_challenge[0]
crypted_challenge = inttostring(crypted_challenge)
else:
key = self._get_referenced_key(p1, p2)
crypted_challenge = vsCrypto.encrypt(cipher, key, data)
return SW["NORMAL"], crypted_challenge
def _get_referenced_key(self, p1, p2):
"""
This method returns the key specified by the p2 parameter. The key may
be stored on the cards filesystem.
:param p1: Specifies the algorithm to use. Needed to know the keylength.
:param p2: Specifies a reference to the key to be used for encryption
== == == == == == == == =============================================
b8 b7 b6 b5 b4 b3 b2 b1 Meaning
== == == == == == == == =============================================
0 0 0 0 0 0 0 0 No information is given
0 - - - - - - - Global reference data(e.g. MF specific key)
1 - - - - - - - Specific reference data(e.g. DF specific key)
- - - x x x x x Number of the secret
== == == == == == == == =============================================
Any other value RFU
"""
key = None
qualifier = p2 & 0x1F
algo = get_referenced_cipher(p1)
keylength = vsCrypto.get_cipher_keylen(algo)
if (p2 == 0x00): #No information given, use the global card key
key = self.cardSecret
#We treat global and specific reference data alike
#elif ((p2 >> 7) == 0x01 or (p2 >> 7) == 0x00):
else:
#Interpret qualifier as an short fid (try to read the key from FS)
if self.mf == None:
raise SwError(SW["ERR_REFNOTUSABLE"])
df = self.mf.currentDF()
fid = df.select("fid", stringtoint(qualifier))
key = fid.readbinary(keylength)
if key != None:
return key
else:
raise SwError(SW["ERR_REFNOTUSABLE"])
def _get_referenced_key(self, p1, p2):
"""
This method returns the key specified by the p2 parameter. The key may
be stored on the cards filesystem.
:param p1: Specifies the algorithm to use. Needed to know the keylength.
:param p2: Specifies a reference to the key to be used for encryption
== == == == == == == == =============================================
b8 b7 b6 b5 b4 b3 b2 b1 Meaning
== == == == == == == == =============================================
0 0 0 0 0 0 0 0 No information is given
0 - - - - - - - Global reference data(e.g. MF specific key)
1 - - - - - - - Specific reference data(e.g. DF specific key)
- - - x x x x x Number of the secret
== == == == == == == == =============================================
Any other value RFU
"""
key = None
qualifier = p2 & 0x1F
algo = get_referenced_cipher(p1)
keylength = vsCrypto.get_cipher_keylen(algo)
if (p2 == 0x00): #No information given, use the global card key
key = self.cardSecret
#We treat global and specific reference data alike
#elif ((p2 >> 7) == 0x01 or (p2 >> 7) == 0x00):
else:
#Interpret qualifier as an short fid (try to read the key from FS)
if self.mf == None:
raise SwError(SW["ERR_REFNOTUSABLE"])
df = self.mf.currentDF()
fid = df.select("fid", stringtoint(qualifier))
key = fid.readbinary(keylength)
if key != None:
return key
else:
raise SwError(SW["ERR_REFNOTUSABLE"])
if __name__ == "__main__":
password = "******"
MyCard = SAM("1234", "1234567890")
try:
print(MyCard.verify(0x00, 0x00, "5678"))
except SwError as e:
print(e.message)
print("Counter = " + str(MyCard.counter))
print(MyCard.verify(0x00, 0x00, "1234"))
print("Counter = " + str(MyCard.counter))
sw, challenge = MyCard.get_challenge(0x00, 0x00, "")
print("Before encryption: " + challenge)
padded = vsCrypto.append_padding("DES3-ECB", challenge)
sw, result_data = MyCard.internal_authenticate(0x00, 0x00, padded)
print("Internal Authenticate status code: %x" % sw)
try:
sw, res = MyCard.external_authenticate(0x00, 0x00, result_data)
except SwError as e:
print(e.message)
sw = e.sw
print("Decryption Status code: %x" % sw)
#SE = Security_Environment(None)
#testvektor = "foobar"
#print "Testvektor = %s" % testvektor
#sw, hash = SE.hash(0x90,0x80,testvektor)
#print "SW after hashing = %s" % sw
if __name__ == "__main__":
password = "******"
MyCard = SAM("1234", "1234567890")
try:
print(MyCard.verify(0x00, 0x00, "5678"))
except SwError as e:
print(e.message)
print("Counter = " + str(MyCard.counter))
print(MyCard.verify(0x00, 0x00, "1234"))
print("Counter = " + str(MyCard.counter))
sw, challenge = MyCard.get_challenge(0x00, 0x00, "")
print("Before encryption: " + challenge)
padded = vsCrypto.append_padding("DES3-ECB", challenge)
sw, result_data = MyCard.internal_authenticate(0x00, 0x00, padded)
print("Internal Authenticate status code: %x" % sw)
try:
sw, res = MyCard.external_authenticate(0x00, 0x00, result_data)
except SwError as e:
print(e.message)
sw = e.sw
print("Decryption Status code: %x" % sw)
#SE = Security_Environment(None)
#testvektor = "foobar"
#print "Testvektor = %s" % testvektor
#sw, hash = SE.hash(0x90,0x80,testvektor)
#print "SW after hashing = %s" % sw
def parse_SM_CAPDU(self, CAPDU, authenticate_header):
"""
This methods parses a data field including Secure Messaging objects.
SM_header indicates whether or not the header of the message shall be
authenticated. It returns an unprotected command APDU
:param CAPDU: The protected CAPDU to be parsed
:param authenticate_header: Whether or not the header should be
included in authentication mechanisms
:returns: Unprotected command APDU
"""
structure = unpack(CAPDU.data)
return_data = [
"",
]
cla = None
ins = None
p1 = None
p2 = None
le = None
if authenticate_header:
to_authenticate = inttostring(CAPDU.cla) + inttostring(CAPDU.ins)+\
inttostring(CAPDU.p1) + inttostring(CAPDU.p2)
to_authenticate = vsCrypto.append_padding(self.cct.blocklength,
to_authenticate)
else:
to_authenticate = ""
for tlv in structure:
tag, length, value = tlv
if tag % 2 == 1: #Include object in checksum calculation
to_authenticate += bertlv_pack([[tag, length, value]])
#SM data objects for encapsulating plain values
if tag in (SM_Class["PLAIN_VALUE_NO_TLV"],
SM_Class["PLAIN_VALUE_NO_TLV_ODD"]):
return_data.append(value) #FIXME: Need TLV coding?
#Encapsulated SM objects. Parse them
#FIXME: Need to pack value into a dummy CAPDU
elif tag in (SM_Class["PLAIN_VALUE_TLV_INCULDING_SM"],
SM_Class["PLAIN_VALUE_TLV_INCULDING_SM_ODD"]):
return_data.append(
self.parse_SM_CAPDU(value, authenticate_header))
#Encapsulated plaintext BER-TLV objects
elif tag in (SM_Class["PLAIN_VALUE_TLV_NO_SM"],
SM_Class["PLAIN_VALUE_TLV_NO_SM_ODD"]):
return_data.append(value)
elif tag in (SM_Class["Ne"], SM_Class["Ne_ODD"]):
le = value
elif tag == SM_Class["PLAIN_COMMAND_HEADER"]:
if len(value) != 8:
raise SwError(SW["ERR_SECMESSOBJECTSINCORRECT"])
else:
cla = value[:2]
ins = value[2:4]
p1 = value[4:6]
p2 = value[6:8]
#SM data objects for confidentiality
if tag in (SM_Class["CRYPTOGRAM_PLAIN_TLV_INCLUDING_SM"],
SM_Class["CRYPTOGRAM_PLAIN_TLV_INCLUDING_SM_ODD"]):
#The cryptogram includes SM objects.
#We decrypt them and parse the objects.
plain = self.decipher(tag, 0x80, value)
#TODO: Need Le = length
return_data.append(
self.parse_SM_CAPDU(plain, authenticate_header))
elif tag in (SM_Class["CRYPTOGRAM_PLAIN_TLV_NO_SM"],
SM_Class["CRYPTOGRAM_PLAIN_TLV_NO_SM_ODD"]):
#The cryptogram includes BER-TLV encoded plaintext.
#We decrypt them and return the objects.
plain = self.decipher(tag, 0x80, value)
return_data.append(plain)
elif tag in (SM_Class["CRYPTOGRAM_PADDING_INDICATOR"],
SM_Class["CRYPTOGRAM_PADDING_INDICATOR_ODD"]):
#The first byte of the data field indicates the padding to use:
"""
Value Meaning
'00' No further indication
'01' Padding as specified in 6.2.3.1
'02' No padding
'1X' One to four secret keys for enciphering information,
not keys ('X' is a bitmap with any value from '0' to 'F')
'11' indicates the first key (e.g., an "even" control word
in a pay TV system)
'12' indicates the second key (e.g., an "odd" control word
in a pay TV system)
'13' indicates the first key followed by the second key
(e.g., a pair of control words in a pay TV system)
'2X' Secret key for enciphering keys, not information
('X' is a reference with any value from '0' to 'F')
(e.g., in a pay TV system, either an operational key
for enciphering control words, or a management key for
enciphering operational keys)
'3X' Private key of an asymmetric key pair ('X' is a
reference with any value from '0' to 'F')
'4X' Password ('X' is a reference with any value from '0' to
'F')
'80' to '8E' Proprietary
"""
padding_indicator = stringtoint(value[0])
plain = self.decipher(tag, 0x80, value[1:])
plain = vsCrypto.strip_padding(self.ct.blocklength, plain,
padding_indicator)
return_data.append(plain)
#SM data objects for authentication
if tag == SM_Class["CHECKSUM"]:
auth = vsCrypto.append_padding(self.cct.blocklength,
to_authenticate)
checksum = self.compute_cryptographic_checksum(
0x8E, 0x80, auth)
if checksum != value:
raise SwError(SW["ERR_SECMESSOBJECTSINCORRECT"])
elif tag == SM_Class["DIGITAL_SIGNATURE"]:
auth = to_authenticate #FIXME: Need padding?
signature = self.compute_digital_signature(0x9E, 0x9A, auth)
if signature != value:
raise SwError(SW["ERR_SECMESSOBJECTSINCORRECT"])
elif tag in (SM_Class["HASH_CODE"], SM_Class["HASH_CODE_ODD"]):
hash = self.hash(p1, p2, to_authenticate)
if hash != value:
raise SwError(SW["ERR_SECMESSOBJECTSINCORRECT"])
#Form unprotected CAPDU
if cla == None:
cla = CAPDU.cla
if ins == None:
ins = CAPDU.ins
if p1 == None:
p1 = CAPDU.p1
if p2 == None:
p2 = CAPDU.p2
# FIXME
#if expected != "":
#raise SwError(SW["ERR_SECMESSOBJECTSMISSING"])
if isinstance(le, str):
# FIXME C_APDU only handles le with strings of length 1. Better patch utils.py to support extended length apdus
le_int = stringtoint(le)
if le_int == 0 and len(le) > 1:
le_int = MAX_EXTENDED_LE
le = le_int
c = C_APDU(cla=cla,
ins=ins,
p1=p1,
p2=p2,
le=le,
data="".join(return_data))
return c
def parse_SM_CAPDU(self, CAPDU, authenticate_header):
"""
This methods parses a data field including Secure Messaging objects.
SM_header indicates whether or not the header of the message shall be
authenticated. It returns an unprotected command APDU
:param CAPDU: The protected CAPDU to be parsed
:param authenticate_header: Whether or not the header should be
included in authentication mechanisms
:returns: Unprotected command APDU
"""
structure = unpack(CAPDU.data)
return_data = ["",]
cla = None
ins = None
p1 = None
p2 = None
le = None
if authenticate_header:
to_authenticate = inttostring(CAPDU.cla) + inttostring(CAPDU.ins)+\
inttostring(CAPDU.p1) + inttostring(CAPDU.p2)
to_authenticate = vsCrypto.append_padding(self.cct.blocklength, to_authenticate)
else:
to_authenticate = ""
for tlv in structure:
tag, length, value = tlv
if tag % 2 == 1: #Include object in checksum calculation
to_authenticate += bertlv_pack([[tag, length, value]])
#SM data objects for encapsulating plain values
if tag in (SM_Class["PLAIN_VALUE_NO_TLV"],
SM_Class["PLAIN_VALUE_NO_TLV_ODD"]):
return_data.append(value) #FIXME: Need TLV coding?
#Encapsulated SM objects. Parse them
#FIXME: Need to pack value into a dummy CAPDU
elif tag in (SM_Class["PLAIN_VALUE_TLV_INCULDING_SM"],
SM_Class["PLAIN_VALUE_TLV_INCULDING_SM_ODD"]):
return_data.append(self.parse_SM_CAPDU(value, authenticate_header))
#Encapsulated plaintext BER-TLV objects
elif tag in (SM_Class["PLAIN_VALUE_TLV_NO_SM"],
SM_Class["PLAIN_VALUE_TLV_NO_SM_ODD"]):
return_data.append(value)
elif tag in (SM_Class["Ne"], SM_Class["Ne_ODD"]):
le = value
elif tag == SM_Class["PLAIN_COMMAND_HEADER"]:
if len(value) != 8:
raise SwError(SW["ERR_SECMESSOBJECTSINCORRECT"])
else:
cla = value[:2]
ins = value[2:4]
p1 = value[4:6]
p2 = value[6:8]
#SM data objects for confidentiality
if tag in (SM_Class["CRYPTOGRAM_PLAIN_TLV_INCLUDING_SM"],
SM_Class["CRYPTOGRAM_PLAIN_TLV_INCLUDING_SM_ODD"]):
#The cryptogram includes SM objects.
#We decrypt them and parse the objects.
plain = self.decipher(tag, 0x80, value)
#TODO: Need Le = length
return_data.append(self.parse_SM_CAPDU(plain, authenticate_header))
elif tag in (SM_Class["CRYPTOGRAM_PLAIN_TLV_NO_SM"],
SM_Class["CRYPTOGRAM_PLAIN_TLV_NO_SM_ODD"]):
#The cryptogram includes BER-TLV encoded plaintext.
#We decrypt them and return the objects.
plain = self.decipher(tag, 0x80, value)
return_data.append(plain)
elif tag in (SM_Class["CRYPTOGRAM_PADDING_INDICATOR"],
SM_Class["CRYPTOGRAM_PADDING_INDICATOR_ODD"]):
#The first byte of the data field indicates the padding to use:
"""
Value Meaning
'00' No further indication
'01' Padding as specified in 6.2.3.1
'02' No padding
'1X' One to four secret keys for enciphering information,
not keys ('X' is a bitmap with any value from '0' to 'F')
'11' indicates the first key (e.g., an "even" control word
in a pay TV system)
'12' indicates the second key (e.g., an "odd" control word
in a pay TV system)
'13' indicates the first key followed by the second key
(e.g., a pair of control words in a pay TV system)
'2X' Secret key for enciphering keys, not information
('X' is a reference with any value from '0' to 'F')
(e.g., in a pay TV system, either an operational key
for enciphering control words, or a management key for
enciphering operational keys)
'3X' Private key of an asymmetric key pair ('X' is a
reference with any value from '0' to 'F')
'4X' Password ('X' is a reference with any value from '0' to
'F')
'80' to '8E' Proprietary
"""
padding_indicator = stringtoint(value[0])
plain = self.decipher(tag, 0x80, value[1:])
plain = vsCrypto.strip_padding(self.ct.blocklength, plain,
padding_indicator)
return_data.append(plain)
#SM data objects for authentication
if tag == SM_Class["CHECKSUM"]:
auth = vsCrypto.append_padding(self.cct.blocklength, to_authenticate)
checksum = self.compute_cryptographic_checksum(0x8E,
0x80,
auth)
if checksum != value:
raise SwError(SW["ERR_SECMESSOBJECTSINCORRECT"])
elif tag == SM_Class["DIGITAL_SIGNATURE"]:
auth = to_authenticate #FIXME: Need padding?
signature = self.compute_digital_signature(0x9E, 0x9A, auth)
if signature != value:
raise SwError(SW["ERR_SECMESSOBJECTSINCORRECT"])
elif tag in (SM_Class["HASH_CODE"], SM_Class["HASH_CODE_ODD"]):
hash = self.hash(p1, p2, to_authenticate)
if hash != value:
raise SwError(SW["ERR_SECMESSOBJECTSINCORRECT"])
#Form unprotected CAPDU
if cla == None:
cla = CAPDU.cla
if ins == None:
ins = CAPDU.ins
if p1 == None:
p1 = CAPDU.p1
if p2 == None:
p2 = CAPDU.p2
if le == None:
le = CAPDU.le
# FIXME
#if expected != "":
#raise SwError(SW["ERR_SECMESSOBJECTSMISSING"])
if isinstance(le, str):
# FIXME C_APDU only handles le with strings of length 1. Better patch utils.py to support extended length apdus
le_int = stringtoint(le)
if le_int == 0 and len(le) > 1:
le_int = MAX_EXTENDED_LE
le = le_int
c = C_APDU(cla=cla, ins=ins, p1=p1, p2=p2, le=le, data="".join(return_data))
return c
