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This resolves LedgerHQ/blue-loader-python#52 #53

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This resolves LedgerHQ/blue-loader-python#52 #53

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198 changes: 102 additions & 96 deletions ledgerblue/checkGenuine.py
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@

import argparse


def get_argparser():
parser = argparse.ArgumentParser(description="""Use attestation to determine if the device is a genuine Ledger
device.""")
Expand All @@ -27,87 +28,92 @@ def get_argparser():
parser.add_argument("--apdu", help="Display APDU log", action='store_true')
return parser


def auto_int(x):
return int(x, 0)


def getDeployedSecretV2(dongle, masterPrivate, targetId, issuerKey):
testMaster = PrivateKey(bytes(masterPrivate))
testMasterPublic = bytearray(testMaster.pubkey.serialize(compressed=False))
targetid = bytearray(struct.pack('>I', targetId))

# identify
apdu = bytearray([0xe0, 0x04, 0x00, 0x00]) + bytearray([len(targetid)]) + targetid
dongle.exchange(apdu)

# walk the chain
nonce = os.urandom(8)
apdu = bytearray([0xe0, 0x50, 0x00, 0x00]) + bytearray([len(nonce)]) + nonce
auth_info = dongle.exchange(apdu)
batch_signer_serial = auth_info[0:4]
deviceNonce = auth_info[4:12]

# if not found, get another pair
#if cardKey != testMasterPublic:
# raise Exception("Invalid batch public key")

dataToSign = bytes(bytearray([0x01]) + testMasterPublic)
signature = testMaster.ecdsa_sign(bytes(dataToSign))
signature = testMaster.ecdsa_serialize(signature)
certificate = bytearray([len(testMasterPublic)]) + testMasterPublic + bytearray([len(signature)]) + signature
apdu = bytearray([0xE0, 0x51, 0x00, 0x00]) + bytearray([len(certificate)]) + certificate
dongle.exchange(apdu)

# provide the ephemeral certificate
ephemeralPrivate = PrivateKey()
ephemeralPublic = bytearray(ephemeralPrivate.pubkey.serialize(compressed=False))
dataToSign = bytes(bytearray([0x11]) + nonce + deviceNonce + ephemeralPublic)
signature = testMaster.ecdsa_sign(bytes(dataToSign))
signature = testMaster.ecdsa_serialize(signature)
certificate = bytearray([len(ephemeralPublic)]) + ephemeralPublic + bytearray([len(signature)]) + signature
apdu = bytearray([0xE0, 0x51, 0x80, 0x00]) + bytearray([len(certificate)]) + certificate
dongle.exchange(apdu)

# walk the device certificates to retrieve the public key to use for authentication
index = 0
last_pub_key = PublicKey(binascii.unhexlify(issuerKey), raw=True)
devicePublicKey = None
while True:
if index == 0:
certificate = bytearray(dongle.exchange(bytearray.fromhex('E052000000')))
elif index == 1:
certificate = bytearray(dongle.exchange(bytearray.fromhex('E052800000')))
else:
break
offset = 1
certificateHeader = certificate[offset : offset + certificate[offset-1]]
offset += certificate[offset-1] + 1
certificatePublicKey = certificate[offset : offset + certificate[offset-1]]
offset += certificate[offset-1] + 1
certificateSignatureArray = certificate[offset : offset + certificate[offset-1]]
certificateSignature = last_pub_key.ecdsa_deserialize(bytes(certificateSignatureArray))
# first cert contains a header field which holds the certificate's public key role
if index == 0:
devicePublicKey = certificatePublicKey
certificateSignedData = bytearray([0x02]) + certificateHeader + certificatePublicKey
# Could check if the device certificate is signed by the issuer public key
# ephemeral key certificate
else:
certificateSignedData = bytearray([0x12]) + deviceNonce + nonce + certificatePublicKey
if not last_pub_key.ecdsa_verify(bytes(certificateSignedData), certificateSignature):
return None
last_pub_key = PublicKey(bytes(certificatePublicKey), raw=True)
index = index + 1

# Commit device ECDH channel
dongle.exchange(bytearray.fromhex('E053000000'))
secret = last_pub_key.ecdh(binascii.unhexlify(ephemeralPrivate.serialize()))
if targetId&0xF == 0x2:
return secret[0:16]
elif targetId&0xF >= 0x3:
ret = {}
ret['ecdh_secret'] = secret
ret['devicePublicKey'] = devicePublicKey
return ret
testMaster = PrivateKey(bytes(masterPrivate))
testMasterPublic = bytearray(testMaster.pubkey.serialize(compressed=False))
targetid = bytearray(struct.pack('>I', targetId))

# identify
apdu = bytearray([0xe0, 0x04, 0x00, 0x00]) + bytearray([len(targetid)]) + targetid
dongle.exchange(apdu)

# walk the chain
nonce = os.urandom(8)
apdu = bytearray([0xe0, 0x50, 0x00, 0x00]) + bytearray([len(nonce)]) + nonce
auth_info = dongle.exchange(apdu)
batch_signer_serial = auth_info[0:4]
deviceNonce = auth_info[4:12]

# if not found, get another pair
# if cardKey != testMasterPublic:
# raise Exception("Invalid batch public key")

dataToSign = bytes(bytearray([0x01]) + testMasterPublic)
signature = testMaster.ecdsa_sign(bytes(dataToSign))
signature = testMaster.ecdsa_serialize(signature)
certificate = bytearray([len(testMasterPublic)]) + testMasterPublic + bytearray([len(signature)]) + signature
apdu = bytearray([0xE0, 0x51, 0x00, 0x00]) + bytearray([len(certificate)]) + certificate
dongle.exchange(apdu)

# provide the ephemeral certificate
ephemeralPrivate = PrivateKey()
ephemeralPublic = bytearray(ephemeralPrivate.pubkey.serialize(compressed=False))
dataToSign = bytes(bytearray([0x11]) + nonce + deviceNonce + ephemeralPublic)
signature = testMaster.ecdsa_sign(bytes(dataToSign))
signature = testMaster.ecdsa_serialize(signature)
certificate = bytearray([len(ephemeralPublic)]) + ephemeralPublic + bytearray([len(signature)]) + signature
apdu = bytearray([0xE0, 0x51, 0x80, 0x00]) + bytearray([len(certificate)]) + certificate
dongle.exchange(apdu)

# walk the device certificates to retrieve the public key to use for authentication
index = 0
last_pub_key = PublicKey(binascii.unhexlify(issuerKey), raw=True)
devicePublicKey = None
while True:
if index == 0:
certificate = bytearray(dongle.exchange(bytearray.fromhex('E052000000')))
elif index == 1:
certificate = bytearray(dongle.exchange(bytearray.fromhex('E052800000')))
else:
break
offset = 1
certificateHeader = certificate[offset : offset + certificate[offset-1]]
offset += certificate[offset-1] + 1
certificatePublicKey = certificate[offset : offset + certificate[offset-1]]
offset += certificate[offset-1] + 1
certificateSignatureArray = certificate[offset : offset + certificate[offset-1]]
certificateSignature = last_pub_key.ecdsa_deserialize(bytes(certificateSignatureArray))
# first cert contains a header field which holds the certificate's public key role
if index == 0:
devicePublicKey = certificatePublicKey
certificateSignedData = bytearray([0x02]) + certificateHeader + certificatePublicKey
# Could check if the device certificate is signed by the issuer public key
# ephemeral key certificate
else:
certificateSignedData = bytearray([0x12]) + deviceNonce + nonce + certificatePublicKey
if not last_pub_key.ecdsa_verify(bytes(certificateSignedData), certificateSignature):
return None
last_pub_key = PublicKey(bytes(certificatePublicKey), raw=True)
index = index + 1

# Commit device ECDH channel
dongle.exchange(bytearray.fromhex('E053000000'))
secret = last_pub_key.ecdh(binascii.unhexlify(ephemeralPrivate.serialize()))
if targetId&0xF == 0x2:
return secret[0:16]
elif targetId&0xF >= 0x3:
return {
'ecdh_secret': secret,
'devicePublicKey': devicePublicKey
}
else:
return None


if __name__ == '__main__':
from .ecWrapper import PrivateKey, PublicKey
Expand All @@ -120,11 +126,11 @@ def getDeployedSecretV2(dongle, masterPrivate, targetId, issuerKey):

args = get_argparser().parse_args()

if args.targetId == None:
args.targetId = 0x31000002
if args.targetId is None:
args.targetId = 0x31000002

if args.issuerKey == None:
args.issuerKey = "0490f5c9d15a0134bb019d2afd0bf297149738459706e7ac5be4abc350a1f818057224fce12ec9a65de18ec34d6e8c24db927835ea1692b14c32e9836a75dad609"
if args.issuerKey is None:
args.issuerKey = "0490f5c9d15a0134bb019d2afd0bf297149738459706e7ac5be4abc350a1f818057224fce12ec9a65de18ec34d6e8c24db927835ea1692b14c32e9836a75dad609"

privateKey = PrivateKey()
publicKey = str(privateKey.pubkey.serialize(compressed=False))
Expand All @@ -138,21 +144,21 @@ def getDeployedSecretV2(dongle, masterPrivate, targetId, issuerKey):
version = None

secret = getDeployedSecretV2(dongle, bytearray.fromhex(args.rootPrivateKey), args.targetId, args.issuerKey)
if secret != None:
try:
loader = HexLoader(dongle, 0xe0, True, secret)
version = loader.getVersion()
genuine = True
apps = loader.listApp()
while len(apps) != 0:
for app in apps:
if (app['flags'] & 0x08):
ui = True
if (app['flags'] & 0x400):
customCA = True
apps = loader.listApp(False)
except:
genuine = False
if secret is not None:
try:
loader = HexLoader(dongle, 0xe0, True, secret)
version = loader.getVersion()
genuine = True
apps = loader.listApp()
while len(apps) != 0:
for app in apps:
if (app['flags'] & 0x08):
ui = True
if (app['flags'] & 0x400):
customCA = True
apps = loader.listApp(False)
except:
genuine = False
if genuine:
if ui:
print ("WARNING : Product is genuine but has a UI application loaded")
Expand Down