oeap with enc

This commit is contained in:
Christoph J. Scherr 2023-06-01 19:45:58 +02:00
parent 4ac13b24f3
commit b263e491aa
Signed by: PlexSheep
GPG Key ID: 25B4ACF7D88186CC
1 changed files with 34 additions and 8 deletions

View File

@ -47,8 +47,13 @@ GIVEN_OAEP = bytearray.fromhex("""
c8956e78ec1c721370663065cbc343deabad9eb6f2aceab6bfed5bea
6543aa3672cddf915c5b564848f4e6ec
""")
SEED_LENGTH = 8 # bytes
GIVEN_C = bytearray.fromhex("""
1b57819fa11340ac8b1843c87db7adb126daa8b6dde1feefd7af721c
ee8f46b6e2c361fc04ac055406a342187388b019dba0bc3f6503f267
b848f7cc86b29a3d0b32730ccf04c5a8a3e1255708cbc6a6a648015e
30f38b1c1c7aa9d2b0e67a775c7ad1cb72ff76c000af46e7cada3c3b
45b5f4d1ec8e0596928cc9b46ee2b53d
""")
def mgf1(seed: bytearray, length: int, hash_func=hashlib.sha256) -> bytearray:
"""
@ -116,7 +121,10 @@ def test_rsa_oaep_inner():
assert result[0] == GIVEN_MASKED_SEED, "is\n%s\ninstead of\n%s" % (result[0].hex(), GIVEN_MASKED_SEED.hex())
assert result[1] == GIVEN_MASKED_DB, "is\n%s\ninstead of\n%s" % (result[1].hex(), GIVEN_MASKED_DB.hex())
def rsa_oaep(ha: bytearray, m: bytearray, verbose: bool, seed: int = random.randint(0, 2**64 - 1)):
def rsa_oaep_noenc(ha: bytearray, m: bytearray, verbose: bool, seed: int = random.randint(0, 2**64 - 1)):
"""
rsa-oeap without encryption
"""
# generate a seed
assert calclen(seed) == 8, "seed is wrong length: %d" % calclen(seed)
l_seed: bytearray = bytearray(seed.to_bytes(calclen(seed), 'big'))
@ -135,9 +143,8 @@ def rsa_oaep(ha: bytearray, m: bytearray, verbose: bool, seed: int = random.rand
assert len(block) == maxlen
if verbose:
print("block:\n%s" % block.hex())
# in this case
assert block == GIVEN_DB, "is\n%s\ninstead of\n%s" % (block.hex(), GIVEN_DB.hex())
assert type(l_seed) == bytearray
# do the inner function
result = rsa_oaep_inner(seed=l_seed, block=block, verbose=verbose)
if verbose:
print()
@ -146,11 +153,29 @@ def rsa_oaep(ha: bytearray, m: bytearray, verbose: bool, seed: int = random.rand
print()
return bytearray(1) + result[0] + result[1]
def test_rsa_oaep_noenc():
r = rsa_oaep_noenc(bytearray(0), GIVEN_MSG, True, GIVEN_SEED)
assert r == GIVEN_OAEP
print(r.hex())
def test_rsa_oaep():
r = rsa_oaep(bytearray(0), GIVEN_MSG, True, GIVEN_SEED)
assert r == GIVEN_OAEP
print(r)
assert r == GIVEN_C
print(r.hex())
def rsa_oaep(
ha: bytearray,
m: bytearray,
verbose: bool,
seed: int = random.randint(0, 2**64 - 1)
) -> bytearray:
"""
rsa-oeap with encryption
"""
r: bytearray = rsa_oaep_noenc(ha, m, verbose, seed)
ri = int.from_bytes(r, 'big')
c = pow(ri, GIVEN_PUB_KEY[1], GIVEN_PUB_KEY[0])
return bytearray(c.to_bytes(calclen(c), 'big'))
def main():
parser = argparse.ArgumentParser(prog="oaep-rsa", description='A hacky Implementation of rsa-oaep')
@ -169,8 +194,9 @@ def main():
args = parser.parse_args()
if args.test:
test_rsa_oaep()
test_rsa_oaep_inner()
test_rsa_oaep_noenc()
test_rsa_oaep()
exit()
if args.hashed_data:
ha = bytearray.fromhex(args.hashed_data)