continued reorganisation

bcrypter/__main__.py

@@ -0,0 +1,12 @@
+from bcrypt.cli import repl
+
+def main():
+    repl()
+
+if __name__ == '__main__':
+    try:
+        main()
+    except KeyboardInterrupt:
+        print('\n[!] SIGINT')
+    except EOFError:
+        print('\n[!] EOF')

bcrypter/cli/__init__.py

@@ -0,0 +1 @@
+

bcrypter/cli/cmd.py

@@ -0,0 +1,46 @@
+from bcrypter.lib.result import Result
+
+class Command:
+    NAME = '[Abstract]Command'
+    ARGS = []
+    FLAGS = []
+    OPTIONS = []
+    def __init__(self, args: list[string]) -> None:
+        pass
+
+    @classmethod
+    def parse(cls: Command, cmd: list[str]) -> Result[Command]:
+        for arg in cmd[1:]:
+            # flag or option
+            if arg.startswith('--'):
+                match = cls._match_arg(arg[2:])
+                if match
+
+    '''
+    Check whether FLAGS and OPTIONS are defined consistently
+    (ie no duplicate names or parsing ambiguity)  
+    '''
+    @classmethod
+    def _is_well_defined(cls: Command) -> Result[None]:
+        raise NotImplementedException('Command.is_consistent()')
+    
+    '''
+    Attempt to match an arg to its flag or option
+    NOTE: _match_arg() assumes _is_well_defined() == True 
+    '''
+    @classmethod
+    def _match_arg(cls: Command, arg: str) -> Result[None]:
+        for opt in chain(cls.FLAGS, cls.OPTIONS):
+            if opt.matches(arg):
+                return Result.succeed(None)
+        return Result.fail()
+
+
+class Builtin(Command):
+    self.NAME = '[Abstract]Builtin'
+    def __init__(self, 
+                 repl_builtins: list[Builtin], 
+                 repl_cmds: list[Command]) -> None:
+        super().__init__()
+        self._repl_builtins = repl_builtins
+        self._repl_cmds = repl_cmds

bcrypter/cli/opt.py

@@ -0,0 +1,21 @@
+from enum import Enum
+
+class OptType(Enum):
+    AbstractOpt # only used by Opt
+    Flag
+    Option
+
+class Opt:
+    _TYPE: OptType = OptType.AbstractOpt
+    def __init__(self, *args) -> None:
+        pass
+
+class Flag(Opt):
+    _TYPE: OptType = OptType.Flag
+    def __init__(self, *args) -> None:
+        super().__init__(*args)
+
+class Option(Opt):
+    _TYPE: OptType = OptType.Option
+    def __init__(self, *args) -> None:
+        super().__init__(*args)

bcrypter/cli/repl.py

@@ -0,0 +1,42 @@
+import readline # GNU readline (ie allows input() history buffer)
+from itertools import chain
+
+from bcrypter.cli.builtins import *
+from bcrypter.cli.commands import *
+from bcrypter.lib.result import Result
+from bcrypter.exceptions import CmdDeclarationError
+
+class REPL:
+    _PROMPT = '>> '
+    _DEFAULT_HISTORY_FILE = '.bcrypter_history'
+
+    _BUILTINS = [
+        BuiltinHelp(),
+    ]
+    _COMMANDS = [
+    ]
+    
+    def __init__(self, history_file: str = _DEFAULT_HISTORY_FILE) -> None:
+        for cmd in chain(REPL._BUILTINS, REPL._COMMANDS):
+            result = cmd._is_consistent():
+            if result.is_err():
+                raise CmdDeclarationError(result.message)
+        self._history_file = history_file
+        readline.read_history_file(self._history_file)
+
+    def __del__(self) -> None:
+        readline.write_history_file(self._history_file)
+
+    def prompt(self) -> str:
+        return input(REPL._PROMPT)
+
+    '''
+    Parse and execute a string command
+    '''
+    def exec(self, cmd: str) -> Result[Command]:
+        cmd = cmd.strip().split()
+        if not len(cmd):
+            return Result.warn('No command given')
+        
+            
+        

bcrypter/debug.py

@@ -0,0 +1,30 @@
+from math import gcd
+from random import randint, randbytes
+
+def main() -> None:
+    if debug_test_random_hashes(10000) != None:
+        R_table = precompute_R(0, 255)
+        x = bytes(input('x: '), 'utf-8')
+        hash_test = hashfn(x, R_table)
+        hash_bcrypt = bcrypt(x)
+        print(f'hashfn: {hash_test}')
+        print(f'bcrypt: {hash_bcrypt}')
+
+    # a = bytes(input("A: "), 'utf-8')
+    # b = bytes(input("B: "), 'utf-8')
+
+    # if a != b and hashfn(a) == hashfn(b):
+    #     print('*** YOU WIN ***')
+    # elif a == b:
+    #     print('Idiot those are the same')
+    # else:
+    #     print("Trivially false!")
+
+
+if __name__ == '__main__':
+    try:
+        main()
+    except KeyboardInterrupt:
+        print('\n[!] Received SIGINT')
+    except EOFError:
+        print('\n[!] Reached EOF')

bcrypter/debug/constants.py

@@ -0,0 +1,13 @@
+'''
+This file provides various methods for determining
+properties, connections, etc for bcrypt's constants. 
+'''
+
+from math import gcd
+
+from bcrypt.hash.rev import H, K, M
+
+def disint_gcds() -> None:
+    print(f'gcd(H,K): {gcd(H,K)}')
+    print(f'gcd(H,M): {gcd(H,M)}')
+    print(f'gcd(K,M): {gcd(K,M)}')

bcrypter/debug/constituents.py

@@ -0,0 +1,18 @@
+'''
+This file provides various "disint" (display internal) methods
+regarding the "constituent functions" that exist in "bcrypt".
+'''
+
+from bcrypt.lib.format import lpad, lpadbin
+
+'''
+Display internal calculations of Rb(b: int) for bcrypt/hashrev.py  
+'''
+def disint_Rb(b: int):
+    Rb = 0
+    for j in range(8):
+        j_sq = j**2
+        Rjb = b << j_sq
+        Rb ^= Rjb
+        print(f'{lpad(j_sq, 2)}: {lpadbin(Rjb, 64)} {Rjb}')
+    print(f'Rb: {lpadbin(Rb, 64)} {Rb}') 

bcrypter/debug/hasheq.py

@@ -0,0 +1,39 @@
+'''
+This file implements debug methods to check whether
+hashrev.bcrypt() operates identically to hash.bcrypt().
+TLDR: test if I made a dumb typo.
+'''
+
+from random import randint, randbytes
+import bcrypt.hash
+import bcrypt.hashrev
+
+def is_bcrypt_eq(x: bytes, R_table: Optional[dict[int, int]] = None) -> bool:
+    return hashrev.bcrypt(x, R_table=R_table) == hash.bcrypt(x)
+
+'''
+Display internals of testing bcrypt implementations
+from bcrypt/hash.py and bcrypt/hashrev.py
+NOTE: By default this runs 10000 trials for
+NOTE: random sequences of length 0-16 bytes.
+'''
+def disint_bcrypt_eq(trials: int = 10000, 
+                     max_bytes: int = 16) -> bytes | None:
+    R_table = hashrev.calc_R_array(max = 255)
+    for i in range(trials):
+        # generate random bytes
+        num_bytes = randint(0, max_bytes)
+        x = randbytes(num_bytes)
+        
+        # test the modified bcrypt with the original    
+        hash_rev = hashrev.bcrypt(x, R_table=R_table)
+        hash_expected = hash.bcrypt(x)
+        if hash_rev != hash_expected:
+            print(f'Your hashfn sucks, big mistake bucko!! (failed iter: {i})')
+            print(f'     Got: {hash_rev}')
+            print(f'Expected: {hash_bcrypt}')
+            print(f'Input Bytes: {[str(b) for b in x]}')
+            return x
+
+    print('Impeccable hashfn holy moly!!')
+    return None

bcrypter/exceptions.py

@@ -0,0 +1,2 @@
+class CmdDeclarationError(Exception):
+    pass

bcrypter/hash/og.py

@@ -0,0 +1,15 @@
+'''
+The unchanged original "bcrypt" function for the CTF (by bpaul)
+'''
+def bcrypt(x: bytes) -> int:
+    h = 18446744073709551614
+
+    for (i, b) in enumerate(x):
+        h *= h * (b + 1)
+        k = 59275109328752 * (i + 1)
+        for j in range(8):
+            k ^= b << (j * j)
+        h += k
+        h %= (2 ** 64)
+
+    return h

bcrypter/hash/rev.py

@@ -0,0 +1,59 @@
+'''
+This file reverse engineers and reconstructs the original 
+"bcrypt" hash function for the CTF (stored in bcrypt/hash.py).
+This reconstructs implements, namely, precomputation of tables
+of values in the hashing. Allowing bulk computation of hashes
+to be significantly faster.
+'''
+
+from array import array
+from typing import Optional
+
+# Constants
+H = 18446744073709551614
+K = 59275109328752
+M = 2**64
+
+def Rjb(j: int, b: int) -> int:
+    return b << j**2
+
+def Rb(b: int) -> int:
+    Rb = 0
+    for j in range(8):
+        Rb ^= Rjb(j, b) 
+    return Rb
+
+'''
+Reconstructed implementation of the "bcrypt" hash function by bpaul.
+NOTE: An optional precomputed R_table is permitted as an arguement.
+'''
+def bcrypt(x: bytes, R_table: Optional[dict[int, int]] = None) -> int:
+    h = -2
+    for i, b in enumerate(x):
+        R = R_table[b] if R_table is not None else Rb(b)
+        h = h**2 * (b+1) + ((K * (i+1)) ^ R)
+        h %= M
+    return h % M
+
+'''
+Returns a hashmap (python dictionary) of b -> R(b)
+for all b such that: min <= b <= max
+'''
+def calc_R_map(min: int = 0,
+               max: int = 255) -> dict[int, int]:
+    R_map = {}
+    # b from min to max (inclusive)
+    for b in range(min, max+1):
+        R_map[b] = Rb(b)
+    return R_map
+
+'''
+Same as calc_R_map() but using an array not a hashmap.
+'''
+def calc_R_array(min: int = 0,
+                 max: int = 255) -> array.array[int]:
+    R_array = array('i', [0]*(max-min))
+    # b from min to max (inclusive)
+    for b in range(min, max+1):
+        R_array[b-min] = Rb(b)
+    return R_array

bcrypter/lib/format.py

@@ -0,0 +1,17 @@
+from typing import Any
+from bcrypt.lib.math import clamp_min
+
+'''
+Apply left padding to str(x) for parameter x: Any 
+'''
+def lpad(x: Any, n: int, pad: chr = ' ') -> str:
+    x = str(x)
+    width = clamp_min(n - len(x), 0)
+    return width * pad + x
+
+'''
+Left pad an integer's binary representation with zeros 
+'''
+def lpadbin(x: int, n: int) -> str:
+    return lpad(bin(x)[2:], n, pad='0')
+

bcrypter/lib/math.py

@@ -0,0 +1,16 @@
+'''
+Implements numeric range clamping (idk why its not in the stdlib...)
+NOTE: the upper and lower bounds for clamping are inclusive 
+'''
+def clamp(x: int, min: int, max: int) -> int:
+    if x < min:
+        return min
+    elif x > max:
+        return max
+    return x
+
+def clamp_min(x: int, min: int) -> int:
+    return x if x > min else min
+
+def clamp_max(x: int, max: int) -> int:
+    return x if x < max else max

bcrypter/lib/result.py

@@ -0,0 +1,26 @@
+from dataclass import dataclass
+from enum import Enum
+
+class ResultState(Enum):
+    WARNING,
+    SUCCESS,
+    FAILURE,    
+
+@dataclass
+class Result[T]:
+    state: ResultState
+    value: T | None
+    message: str
+
+    @classmethod
+    def warn(cls: Result, message: str, value: T | None = NOne) -> Result:
+        cls(ResultState.WARNING, value, message)
+    @classmethod
+    def succeed(cls: Result, value: T, message: str = 'Ok') -> Result:
+        cls(ResultState.SUCCESS, value, message)
+    @classmethod
+    def fail(cls: Result, message: str, value: T | None = None) -> Result:
+        cls(ResultState.WARNING, value, message)
+
+    def is_ok(self) -> bool: return not self.is_err()
+    def is_err(self) -> bool: return self.state == ResultState.FAILURE