def make_bootloader():
"""
Build the bootloader from source.
This also loads all keys (symmetric and non-symmetric) into secret_build_output.txt
Return:
True if successful, False otherwise.
"""
# Change into directory containing bootloader.
bootloader = FILE_DIR / '..' / 'bootloader'
os.chdir(bootloader)
rsa_key = RSA.generate(2048)
#need to provision: RSA modulus, exponent, exponent size
modulus = rsa_key.publickey().n
exponent = rsa_key.publickey().e
exponent_size = len(exponent)
# f = open('mykey.pem','wb')
# f.write(rsa_key.export_key('PEM'))
# f.close()
aes_key = AES.get_random_bytes(16)
# print('BEFORE WRITING: \n')
# print('RSA key: ', rsa_key)
# print('AES key: ', aes_key)
with open('secret_build_output.txt', 'w+b') as fh:
fh.write(aes_key)
def encrypt(key, data):
iv = AES.get_random_bytes(16)
cipher = AES.new(key, AES.MODE_CBC, iv=iv)
b_data = (data).encode()
b_data += b'\x00' * (16 - (len(b_data) % 16))
print("plain_text = ", b_data)
ciphertext = cipher.encrypt(b_data)
print("cipher_text = ", ciphertext)
return ciphertext, iv
def make_bootloader():
"""
Build the bootloader from source.
This also loads all keys (symmetric and non-symmetric) into secret_build_output.txt
Return:
True if successful, False otherwise.
"""
# Change into directory containing bootloader.
rsa_key = RSA.generate(
2048
) # generates a private RSA key object so that a public exponent and modulus can be created
#need to provision: RSA modulus, exponent, exponent size
# public RSA modulus
modulus = rsa_key.publickey().n
# public RSA exponent
exponent = rsa_key.publickey().e
# size of exponent, for later use in authentication
exponent_size = 8
aes_key = AES.get_random_bytes(16) # generates a random 16 byte AES key
with open(
'secret_build_output.txt', 'wb+'
) as fh: # writes the AES and RSA private key in the {secret_build_output.txt} file
print("test")
fh.write(
aes_key
) # this allows the fw_protect tool to import these keys and encrypt/sign data
fh.write(rsa_key.export_key())
bootloader = FILE_DIR / '..' / 'bootloader'
os.chdir(bootloader)
subprocess.call(
'make clean',
shell=True) #allows us to pass in arguments to the make file
#sets all variables in makefile according to ones above (the aes symmetric key, modulus, exponent, and exponent size)
status = subprocess.call(
f'make KEY={to_c_array(aes_key)} MOD={to_c_array((rsa_key.publickey().n).to_bytes(256, "big"))} EXP={to_c_array(struct.pack(">Q", rsa_key.publickey().e))} E_SIZE=8',
shell=True)
# Return True if make returned 0, otherwise return False.
return (status == 0)
def aes_make_key(key_len=128):
key = AES.get_random_bytes(key_len//8)
iv = AES.get_random_bytes(128//8)
return key, iv
tmp = (tmp >> 1) ^ self.poly
else:
tmp >>= 1
byte >>= 1
self.table.append(tmp)
def calc(self, string):
value = self.mask
for c in string:
value = self.table[(ord(c) ^ value) & 0xFF] ^ (value >> 8)
return struct.pack('>I', (-1 - value) & self.mask)
sys.stdout = Unbuffered(sys.stdout)
FLAG = open('flag.txt').read().strip()
KEY = AES.get_random_bytes(16)
CC = Cyclic()
def intro():
print '''
````````````````````````````````````````````````````````````````
`````````````````````...----::::::::::---..`````````````````````
`````````````-/+syhdddmmmmmmddddddddmmmmmmddhhyyso+:````````````
````````````.yhhhhdddmmmmmmddddddddddmmmmmdddddhhhhh+```````````
````````````-yhhhhdddmmmmmddddddddddddddmmmddddhhhhhs```````````
````````````:yhhhhhhhddddmdddddddddddddddddhhhhhhhhhy```````````
````````````/yyo------:/+shdddddddddddhso++::--:+yyyy```````````
````````````/yyoyyyyys+:.``:ohdddddho-``-/osyhyyo+yyy.``````````
````````````/syyyhhhhhhhys/-`-hdddy.`-+syhhhhhhhyyyyy.``````````
````````````/ssyyyyyyyyyyyssosddddhoosyyyyyyyyyyyyyss```````````
