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oeap works

This commit is contained in:
Christoph J. Scherr 2023-06-01 19:33:30 +02:00
parent 580f2c4f67
commit 4ac13b24f3
Signed by: PlexSheep
GPG Key ID: 25B4ACF7D88186CC
1 changed files with 103 additions and 47 deletions
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150
src-py/plexcryptool/scripts/oaep_rsa.py
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@ -7,12 +7,46 @@ Perform RSA-OAEP
@source: https://git.cscherr.de/PlexSheep/plexcryptool/src/branch/master/plexcryptool/trash-hash.py
"""
import argparse
import hashlib
import random
from math import floor
# the given key in the assignment
GIVEN_PUB_KEY = (0xAF5466C26A6B662AC98C06023501C9DF6036B065BD1F6804B1FC86307718DA4048211FD68A06917DE6F81DC018DCAF84B38AB77A6538BA2FE6664D3FB81E4A0886BBCDAB071AD6823FE20DF1CD67D33FB6CC5DA519F69B11F3D48534074A83F03A5A9545427720A30A27432E94970155A026572E358072023061AF65A2A18E85, 0x10001)
GIVEN_MASK_FOR_DB = bytearray.fromhex("""
ea600669f6f16b3a2ad05d4b6d9b23911c8cc432fddd8d34a68d88af
3d787b7eebf6cd1b720812086758ce56e24ab819ccd8fb5eedb1cae9
f6f895667d7f89d0454b828777ecabc040a649c8956e78ec1c721370
663065cbc343deabad9eb6f2aceab6bfed5beb232cc55413bfffa06e
68627d7ec3ded5
""")
GIVEN_DB = bytearray.fromhex("""
00000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000001466f6f626172203132
33343536373839
""")
GIVEN_MASKED_DB = bytearray.fromhex("""
ea600669f6f16b3a2ad05d4b6d9b23911c8cc432fddd8d34a68d88af
3d787b7eebf6cd1b720812086758ce56e24ab819ccd8fb5eedb1cae9
f6f895667d7f89d0454b828777ecabc040a649c8956e78ec1c721370
663065cbc343deabad9eb6f2aceab6bfed5bea6543aa3672cddf915c
5b564848f4e6ec
""")
GIVEN_MASK_FOR_SEED = bytearray.fromhex("713162084a4e0e6d ")
GIVEN_MASKED_SEED = bytearray.fromhex("db2040f6425bb082")
GIVEN_SEED = 0xaa1122fe0815beef
GIVEN_SEED_BYTES = bytearray.fromhex("aa1122fe0815beef")
GIVEN_MSG = bytearray.fromhex("466f6f62617220313233343536373839")
GIVEN_OAEP = bytearray.fromhex("""
00db2040f6425bb082ea600669f6f16b3a2ad05d4b6d9b23911c8cc4
32fddd8d34a68d88af3d787b7eebf6cd1b720812086758ce56e24ab8
19ccd8fb5eedb1cae9f6f895667d7f89d0454b828777ecabc040a649
c8956e78ec1c721370663065cbc343deabad9eb6f2aceab6bfed5bea
6543aa3672cddf915c5b564848f4e6ec
""")
SEED_LENGTH = 8 # bytes
@ -60,80 +94,102 @@ def calclen(n: int) -> int:
else:
return floor(len)
def rsa_oaep_inner(seed: bytearray, block: bytearray) -> tuple[bytearray, bytearray]:
def rsa_oaep_inner(seed: bytearray, block: bytearray, verbose: bool) -> tuple[bytearray, bytearray]:
"""
inner function of rsa-oaep
"""
assert type(seed) == bytearray
mgf_seed = mgf1(seed, len(block))
print("mgf1(seed):\n%s" % mgf_seed.hex())
masked_db = byte_xor(mgf_seed, block)
print("mgf1(seed) ^ block:\n%s" % masked_db.hex())
mask_seed = mgf1(masked_db, len(seed))
print("mgf1(mgf1(seed) ^ block):\n%s" % mask_seed.hex())
masked_seed = byte_xor(seed, mask_seed)
print("mgf1(mgf1(seed) ^ block) ^ seed:\n%s" % masked_seed.hex())
if verbose:
print("mgf1(seed):\n%s" % mgf_seed.hex())
print("mgf1(seed) ^ block:\n%s" % masked_db.hex())
print("mgf1(mgf1(seed) ^ block):\n%s" % mask_seed.hex())
print("mgf1(mgf1(seed) ^ block) ^ seed:\n%s" % masked_seed.hex())
return (masked_seed, masked_db)
def test_rsa_oaep_inner():
seed: bytearray = bytearray.fromhex("aa1122fe0815beef")
db: bytearray = bytearray.fromhex("""
00000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000001466f6f626172203132
33343536373839
""")
print("seed:\n%s" % seed.hex())
print("db:\n%s" % db.hex())
result = rsa_oaep_inner(GIVEN_SEED_BYTES, GIVEN_DB, True)
result = rsa_oaep_inner(seed, db)
GIVEN_MASK_FOR_DB = bytearray.fromhex("""
ea600669f6f16b3a2ad05d4b6d9b23911c8cc432fddd8d34a68d88af
3d787b7eebf6cd1b720812086758ce56e24ab819ccd8fb5eedb1cae9
f6f895667d7f89d0454b828777ecabc040a649c8956e78ec1c721370
663065cbc343deabad9eb6f2aceab6bfed5beb232cc55413bfffa06e
68627d7ec3ded5
""")
GIVEN_MASKED_DB = bytearray.fromhex("""
ea600669f6f16b3a2ad05d4b6d9b23911c8cc432fddd8d34a68d88af
3d787b7eebf6cd1b720812086758ce56e24ab819ccd8fb5eedb1cae9
f6f895667d7f89d0454b828777ecabc040a649c8956e78ec1c721370
663065cbc343deabad9eb6f2aceab6bfed5bea6543aa3672cddf915c
5b564848f4e6ec
""")
GIVEN_MASK_FOR_SEED = bytearray.fromhex("713162084a4e0e6d ")
GIVEN_MASKED_SEED = bytearray.fromhex("db2040f6425bb082")
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):
def rsa_oaep(ha: bytearray, m: bytearray, verbose: bool, seed: int = random.randint(0, 2**64 - 1)):
# generate a seed
seed = random.randint(0, 2**64 - 1)
seed = bytearray(seed.to_bytes(calclen(seed), 'big'))
assert calclen(seed) == 8, "seed is wrong length: %d" % calclen(seed)
l_seed: bytearray = bytearray(seed.to_bytes(calclen(seed), 'big'))
# build the message
block: bytearray = bytearray(0)
assert len(block) == 0
maxlen = calclen(GIVEN_PUB_KEY[0]) - 1 - len(l_seed)
curlen = 0
curlen += len(ha)
curlen += len(m)
block += ha
block += bytearray(calclen(GIVEN_PUB_KEY[0]) - curlen)
block += bytearray(maxlen - curlen - 1)
block += bytearray(0x01.to_bytes())
block += m
assert len(block) == calclen(GIVEN_PUB_KEY[0]), "curlen:\n%s\nmodlen:\n%s" % (curlen, calclen(GIVEN_PUB_KEY[0]))
result = rsa_oaep_inner(seed, block)
print()
print(result[0].hex())
print(result[1].hex())
print()
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
result = rsa_oaep_inner(seed=l_seed, block=block, verbose=verbose)
if verbose:
print()
print(result[0].hex())
print(result[1].hex())
print()
return bytearray(1) + result[0] + result[1]
def test_rsa_oaep():
r = rsa_oaep(bytearray(0), GIVEN_MSG, True, GIVEN_SEED)
assert r == GIVEN_OAEP
print(r)
def main():
ha = bytearray(0)
m = bytearray.fromhex("466f6f62617220313233343536373839")
r = rsa_oaep(ha, m)
print("final:\n%s" % r.hex())
parser = argparse.ArgumentParser(prog="oaep-rsa", description='A hacky Implementation of rsa-oaep')
parser.add_argument('-m', '--message', type=str, metavar="MSG",
help='the message of the oaep')
parser.add_argument('-rs', '--random-seed', action="store_true",
help='a random seed')
parser.add_argument('-s', '--seed', type=int,
help='a custom seed')
parser.add_argument('-a', '--hashed-data', type=str,
help='append some auth hashed stuff')
parser.add_argument('-v', '--verbose', action="store_true",
help='append some auth hashed stuff')
parser.add_argument('-t', '--test', action="store_true",
help='perform tests')
args = parser.parse_args()
if args.test:
test_rsa_oaep()
test_rsa_oaep_inner()
exit()
if args.hashed_data:
ha = bytearray.fromhex(args.hashed_data)
else:
ha = bytearray(0)
if args.message:
m = bytearray.fromhex(args.message)
else:
m = bytearray.fromhex("466f6f62617220313233343536373839")
if args.seed:
seed: int = args.seed
r = rsa_oaep(ha, m, args.verbose, seed)
elif args.random_seed:
seed = random.randint(0, 2**64 - 1)
r = rsa_oaep(ha, m, args.verbose, seed)
else:
seed = GIVEN_SEED
r = rsa_oaep(ha, m, args.verbose, seed)
print("result:\n%s" % r.hex())
if __name__ == "__main__":
main()