commit 09ca6cd26bcb24d7df0f02eb9d24c0f07c14946a
parent a3be9e519c1f8c371f55190ab2bbd1344e6ce560
Author: oscarbenedito <oscar@oscarbenedito.com>
Date: Wed, 11 Mar 2020 22:15:37 +0100
Hexadecimal to Base64 translator added
Diffstat:
2 files changed, 119 insertions(+), 0 deletions(-)
diff --git a/hex-base64-translator/README.md b/hex-base64-translator/README.md
@@ -0,0 +1,15 @@
+# Hex and Base64 translator
+
+This script simply translates hexadecimal strings into Base64 strings (by converting them into bits and then reading the bits as Base64) and the inverse process.
+
+The goal of this program is make a password containing only characters in the Base64 alphabet and then being able to split the secret between different parties using [ssss](http://point-at-infinity.org/ssss/) (with the hexadecimal option). With this, an attacker can't get any advantage by discarding unvalid answers, since they are all valid (when running the program normally, you can get "binary" secrets or "ASCII" secrets).
+
+All this trouble is due to the fact that I am not sure if there is a way for an attacker with some shares of the secret to avoid making a brute-force attack by knowing the implementation of ssss and anticipate binary (and therefore invalid) results.
+
+## License
+
+The program is licensed under the GNU General Public License version 3 (available [here](https://www.gnu.org/licenses/gpl-3.0.html)).
+
+## Author
+
+- **Oscar Benedito** - oscar@oscarbenedito.com
diff --git a/hex-base64-translator/hex-base64-translator.py b/hex-base64-translator/hex-base64-translator.py
@@ -0,0 +1,104 @@
+#!/usr/bin/env python3
+# Copyright (C) 2020 Oscar Benedito
+#
+# This file is part of Utilities.
+#
+# Utilities is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Utilities is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Utilities. If not, see <https://www.gnu.org/licenses/>.
+
+import sys
+from getpass import getpass
+
+def char_to_bits(c):
+ n = ord(c)
+ if n >= 65 and n <= 90:
+ return bin(n - 65)[2:].zfill(6)
+ elif n >= 97 and n <= 122:
+ return bin(n - 71)[2:].zfill(6)
+ elif n >= 48 and n <= 57:
+ return bin(n + 4)[2:].zfill(6)
+ elif (c == '+'):
+ return bin(62)[2:].zfill(6)
+ elif (c == '/'):
+ return bin(63)[2:].zfill(6)
+ else:
+ sys.exit('Error, ' + c + ' is not a Base64 character.', file=sys.stderr)
+
+def bits_to_char(s):
+ n = int(s, 2)
+ if n < 26:
+ return chr(n + 65)
+ elif n < 52:
+ return chr(n + 71)
+ elif n < 62:
+ return chr(n - 4)
+ elif n == 62:
+ return '+'
+ elif n == 63:
+ return '/'
+ else:
+ sys.exit('Error, ' + s + ' (' + str(n) + ') is not a binary number lower than 64.', file=sys.stderr)
+
+def base64_to_hex(s):
+ if len(s) % 2:
+ print('WARNING: Number of Base64 characters is not multiple of 2. Adding zeros to string.', file=sys.stderr)
+ s = 'A' + s
+
+ ret = ''
+ carry = ''
+ while len(s) > 0:
+ cs = s[:2]
+ bs = char_to_bits(s[0]) + char_to_bits(s[1])
+ ret += hex(int(bs, 2))[2:].zfill(3)
+ s = s[2:]
+
+ return ret
+
+def hex_to_base64(s):
+ if len(s) % 3:
+ print('WARNING: Number of hexadecimal values is not a multiple of 3. Adding zeros to string.', file=sys.stderr)
+ s = '0'*(3 - (len(s) % 3)) + s
+
+ ret = ''
+ while len(s) > 0:
+ bs = bin(int(s[:3], 16))[2:].zfill(12)
+ ret += bits_to_char(bs[:6])
+ ret += bits_to_char(bs[6:])
+ s = s[3:]
+
+ return ret
+
+
+if len(sys.argv) != 2 or (sys.argv[1] != 'base64-to-hex' and sys.argv[1] != 'hex-to-base64'):
+ sys.exit('Usage: ' + sys.argv[0] + ' base64-to-hex | hex-to-base64.')
+
+if sys.argv[1] == 'base64-to-hex':
+ inp = getpass(prompt = 'Base64 secret: ')
+ print('')
+ out = base64_to_hex(inp)
+ print('-'*80)
+ print('Secret in hexadecimal:', out)
+ print('-'*80)
+
+elif sys.argv[1] == 'hex-to-base64':
+ inp = getpass(prompt = 'Hexadecimal secret: ')
+ print('')
+ out = hex_to_base64(inp)
+ print('-'*80)
+ print('Secret in Base64:', out)
+ print('-'*80)
+ if inp[0] == '0' and len(inp) % 2 == 0:
+ out = hex_to_base64(inp[1:])
+ print('-'*80)
+ print('Due to SSSS having an output with an even number of characters, your secret could be:', out)
+ print('-'*80)
