🔓 Corsair

RSA low randomness key cracker.

📃 Table of contents

Corsair
My Corsair
Useful Commands
1. GCC Commands
2. Valgrind Commands
Software
Theory
Sources
Notes
To Do

🔓 Corsair

Resumen: Bloque de criptografía

📜 Introducción

Este proyecto introduce conceptos específicos sobre la fortaleza del algoritmo RSA y sus vulnerabilidades potenciales. Si bien el algoritmo es considerado suficientemente fuerte para la potencia computacional de los dispositivos actuales, ciertas formas de utilizarlo pueden llevar a graves problemas de seguridad.

📖 Instrucciones generales

Para este proyecto, debes usar C como lenguaje. La lista de funciones pemitidas es la siguiente: • Todas las funciones de <math.h>
• Todas las funciones de <string.h>
• La librería openssl
• Todo lo puesto en cabecera del ejercicio.

❗ Parte Obligatoria

La seguridad en la criptografía asimétrica usando claves RSA se basa en la premisa de que es muy difícil computacionalmente factorizar los dos factores primos de un número.

“Multiplicar dos números primos p y q para obtener n” es una operación sencilla y su complejidad no aumenta drásticamente cuando los números crecen:

[1736640013 · 1230300287 = 2136588706409583731]

En cambio, la operación inversa, “dado un número n obtener sus dos factores pri- mos”, es una operación que se vuelve computacionalmente inviable cuando los números involucrados son lo suficientemente grandes.

Para generar la pareja de claves, el algoritmo RSA crea una clave pública y privada usando este concepto. Simplificando la generación de las claves, los números primos elegidos aleatoriamente p y q se multiplican para crear el módulo n que se usará tanto en la clave privada como en la pública. Este módulo n es público pero los factores primos p y q no.

[? · ? = 2136588706409583731]

Si tenemos dos certificados generados en un sistema cuyo generador de números alea- torios estaba configurado al mínimo y por tanto en el que la entropía era mínima. . .

Esto puede haber dado pie a repeticiones de números primos durante distintas generaciones, se podría haber dado el caso en el que dos módulos compartan el mismo número p o q.

[n1 = p1 · q1] [n2 = p1 · q2]

Ejercicio 1 - coRSAir


Nombre de función	corsair
Archivos a entregar	.c, .h
Funciones autorizadas	printf, snprintf, write, read, open, close, malloc, free
Descripción	Bloque de criptografía: cifrados vulnerables

Con esta información, crearás una herramienta que:

• Lea la clave pública de estos certificados y obtenga el módulo y exponente. Calcular el resto de los datos necesarios.

• Construya la clave privada a partir de dos primos y su producto, y de ahí saque la clave simétrica cifrada con él.

• ¡Descifre el mensaje!

➕ Parte Bonus

La evaluación de los bonus se hará SI Y SOLO SI la parte obligatoria es PERFECTA. De lo contrario, los bonus serán totalmente IGNORADOS.

Puedes mejorar tu proyecto con las siguientes características:

• Documentación detallada y clara de todos los fundamentos teóricos detrás del pro- yecto

• Implementación propia de una librería o conjunto de funciones en C para operar con enteros de gran tamaño.

• Todo lo que se te ocurra... podrás justificarlo todo durante la evaluación.

🔐 My Corsair

Features:

❓ Corsair Help

wrongUserInputBool = 0 
helpBool = 1 
pFuncBool = 0 
pPath =  
fFuncBool = 0 
pemFileOne4Func =  
pemFileTwo4Func =  
binFileOne4fFunc =  
binFileTwo4fFunc =  
cFuncBool = 0 
BN_One_cFunc =  
BN_Two_cFunc =  
xFuncBool = 0 
number_xFunc = 0 
gFuncBool = 0 
number_gFunc = 0 
dFUncBool = 0 
dPrivateKeyFile =   
dBinFile =  
eFuncBool = 0 
eEncryptPublicKey =   
eEncryptTextFile =  
outputPathBool = 0
OutputPath = 

DEBUG - pwd = /home/spider/Documents/Portfolio/PortfolioFiles/CyberSecurity42/Modules/PortfolioProjects/corsair 
corsair is a program used to crack RSA passwords and work with RSA keys. 

  The capabilities of this program are the following: 

  -h      --> Prints the Program help.
  
  -p (path)   --> The main function. Reads all .pem files in the -p path and tries to crack the private password with other .pem files in the folder. If the provate key is cracked it decodes the .bin file 
              with equal name as the private key '.pem' file1
              Example of files in the folder
                1.pem
                2.pem 
                1.bin
                2.bin
              If the key of '1.pem' and '2.pem' was cracked, the program decrypts the files 2.bin and 2.bin.
              It also generates a .pem file for each public key cracked with the respective private key.
              This file will be named after the file containing the public key, the key type, the program name and the version of the program used.
              As example if 1.pem and 2.pem files containing a public key where cracked, two files will be created containing the private key. 
              Those files will be named for corsair version 0.001:
                1_privateKey_Corsair_0-001.pem
                2_privateKey_Corsair_0-001.pem
              The function also saves the decoded message in .txt files, which will be named as:
                1_decryptedMessage_Corsair_0-001.txt
                2_decryptedMessage_Corsair_0-001.txt
   
  -f (file1.pem file2.pem file1.bin file2.bin)  --> The flag -f does the same as the flag -p but for 4 specific files. It does not read recursively a path looking for files to crack.
                                                    This flag allows working with files which are not named for the use of the function used for -p
                                                    It creates the same files as the function used with the -p flag (if key was cracked)


  -g (N)      --> Generate N 'YES Random' public keys, private keys and encrypted messages in order to check the functionability of the -d path function.


 - FOR VERSION 0.002 

  -C ('BIGNUM IN ASCII' 'BIGNUM IN ASCII')-C ('BIGNUM IN ASCII' 'BIGNUM IN ASCII')       --> The flag C calculate the RSA keys for the two BIGNUMs give in ASCII format and generates 2 key .pem files. One for the public key
                                                      and other for the private key.
                                                      Remember that the numbers need to:
                                                        1. Be integers (No Float are allowed)
                                                        2. Be Primes
                                                        3. Not be the same number
                                                    
  -o (outputPath)                                 --> Specifies the ouput path where the output files will be stored. If not output path is specified the relative path './CorsairOutputV0-001/' will be used
                                                     [WARNING] The program creates the path if it does NOT exist, but does NOT check for file 'collision'. Therefore some files in the ouput folder could be deleted.    
                                                    
  -h        --> Show the help of the program into terminal.

  -x (N)       --> Generate N 'NOT Random' public keys, private keys and encrypted messages in order to check the functionability of the -p path function. (USED FOR DEBUGGING and TESTING)

  -d (private_key_file.pem encrypted_file.bin)   --> Tries to decrypt the ecrypted_file.bin using the private key contained into the private_key_file.pem.
                                                      If succes shows the decrypted message into terminal.
                                                      If fails shows error into terminal.
  -e (public_key_file.pem input_text_file.txt)   --> if the length of the text of the input_text_file is lower or equal than the maximum encryption lenght,
										this function encrypts the text and save it into the file given with the -o flag. 



  ToDo for Version 0.002
  - Input Read Arguments Function With Parameters stored into Struct and check consistency of gieven parameters
  - Help Print Function
  - Create Output Folder if needed
  - -p Function
    - Clean
    - Create .pem files and save into output with name public key files
    - Create .txt files and save into output path with decrypted message
    - Free all variables
  - -f Function
    - SAME as -p but for 4 files
  - -C function
  - -x function using the same function as -C
  - .g function using the same function as -C
  - -d function 



  ToDo for Version 0.002
  - H (HASH)   --> Specifies the HASH to be used for all functions 
  - F (file.pem) --> Cracks the public key stored into file.pem 
  - Clean Code
  - Assure all Variables are freedn
  - All functions with 'no deprecated' open ssl functions

📁 Files

The list of files used for the project is the following:

FILE	Function
README.md (this file)	Readme file with some information about this project.
corsair.c	Corsair program written in C
corsair	Compiled Corsair Program
corsairTest.sh	Bash Script used to test the several Corsair functionalities
testLeaks.sh	Bash Script used to test leaks for all the Corsair functionalities
testLeaksOld.sh	Old Bash Script used to test leaks for all the Corsair functionalities without the capability of changing de output directory
testX.sh	Bash Script to test recall capability of corsair program
Sources/	Folder with several files used in order to test the functions of the program.

👷 Build

The program can be build with the gcc for two main goals:

Distribution: Use the program normally.
Debugging: Test, debug and improve the code.

Compile for distribution

Compile standard:

	gcc corsair.c -o corsair -lm -lssl -lcrypto -w
	OR
	gcc corsair.c -o ../binaries/corsair -lm -lssl -lcrypto -w

Compile for Debugging

Compile Debugging:

	gcc -o corsair -std=c11 -Wall -ggdb3 corsair.c -lssl -lcrypto -w
	gcc -o corsair -std=c11 -Wall -ggdb3 corsair.c -lssl -lcrypto -w -lm
	
	#OR
	
	gcc -o ../binaries/corsair -std=c11 -Wall -ggdb3 corsair.c -lssl -lcrypto -w
	gcc -o ../binaries/corsair -std=c11 -Wall -ggdb3 corsair.c -lssl -lcrypto -w -lm

💧 Leaks

Compile the program with -dgb flag

	gcc -o corsair -std=c11 -Wall -ggdb3 corsair.c -lssl -lcrypto -w -lm

Run the compiled program using the utily valgrind:

	dirValRes="valgrindRes20/"
	dirValResOut="./""$dirValRes"
	mkdir $dirValRes
	
	valgrind --log-file="$dirValRes"Xout01.file --leak-check=yes --tool=memcheck ./corsair -x  4 -o "$dirValResOut"valXOut01/

[!] - Some leak tests are in the file: ./tests/testsLeaks.sh

🎯 Tests

# Test the path option:
./corsair -p ../examples/challenge_corsair/

More test in the bash script "corsairTest.sh" in the main project folder.

🔨 Use Examples

./corsair -h
./corsair -g 1 -o ./keys/
./corsair -f ../examples/challenge_corsair/29.pem ../examples/challenge_corsair/82.pem ../examples/challenge_corsair/29.bin ../examples/challenge_corsair/82.bin -o ./outNow3/
./corsair -p ../examples/challenge_corsair/ -o ./OutputPath13/

🔧 Software

GCC - GNU Compiler Collection

GCC Official Website

Installation:

apt install gcc

GDB

GDB Official Website

Installation:

apt isntall gdb

OpenSSL

OpenSSL Official Website

Installation:

apt install libssl-dev  openssl

Instructions in order to install other versions:

1. Install open ssl 3 or superior in debian:
	nano /etc/apt/sources.list
	
	ADD
	
	deb http://deb.debian.org/debian testing bullseye main
	deb-src http://deb.debian.org/debian testing bullseye main

	deb http://deb.debian.org/debian testing bullseye-security main
	deb-src http://deb.debian.org/debian testing bullseye-security main
	
	
	run 
	apt install openssl
	openssl version
	apt install libssl-dev
	
	apt install openssl
	apt install libssl-dev
	apt install gcc gdb valgrind 
	
	apt install openssl libssl-dev gcc gdb

Valgrind

Valgrind Official Website

Installation:

apt install valgrind

👇 Useful Commands

GCC Commands

GDB Commands

In order to debug the C program Corsair:

1. Compile program:
	gcc -o corsair -std=c11 -Wall -ggdb3 corsair.c -lssl -lcrypto -w -lm

2. Run Program using gdb
	gdb ./corsair

3. run Command + arguments:
	run -x 10 -o ./ouputX/

4. If fault occurs use "where" command to see traceback.
	where

OpenSSL Commands

openssl rsa -check -in privateKey.pem

openssl rsa -pubin -in 1699361481_1_publicKey.pem

openssl rsa -in alice_private.pem -pubout > alice_public.pem

openssl rsautl -encrypt -inkey bob_public.pem -pubin -in top_secret.txt -out top_secret.enc

openssl rsautl -decrypt -inkey privateKey.pem -in message.bin > message.txt

cat $(openssl rsautl -decrypt -inkey privateKey.pem -in message.bin)

cat $(openssl pkeyutl -decrypt -inkey 1699361826-privateKey.pem -in 1699361826-publicKey.bin)

Valgrind Commands

In order to correct corsair: #Source:

		valgrind --log-file=output10.file --leak-check=yes --tool=memcheck ./corsair -h
		
		valgrind --log-file=output20.file --leak-check=yes --tool=memcheck ./corsair -g 1 -o ./keys/
		
		valgrind --log-file=output30.file --leak-check=yes --tool=memcheck ./corsair -f ./Sources/challenge_corsair/29.pem ./Sources/challenge_corsair/82.pem ./Sources/challenge_corsair/29.bin ./Sources/challenge_corsair/82.bin -o ./outNow3/
		
		./corsair -f ./Sources/challenge_corsair/97.pem ./Sources/challenge_corsair/60.pem ./Sources/challenge_corsm ./97.bin ./Sources/challenge_c.bin r/60.bin -o ./outNow3/


		
		valgrind --log-file=output40.file --leak-check=yes --tool=memcheck ./corsair -p ./Sources/challenge_corsair/ -o ./OutputPath13/
		valgrind --log-file=output41.file --leak-check=yes --track-origins=yes --tool=memcheck ./corsair -p ./Sources/challenge_corsair/ -o ./OutputPath13/
		valgrind --log-file=output41.file --leak-check=full --track-origins=yes --tool=memcheck ./corsair -p ./Sources/challenge_corsair/ -o ./OutputPath13/

ERROR MESSSAGE VALGRIND EXAMPLE

==43284== Memcheck, a memory error detector
==43284== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al.
==43284== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info
==43284== Command: ./a.out
==43284== Parent PID: 39695
==43284== 
==43284== Invalid write of size 4
==43284==    at 0x4004B6: f (in /tmp/a.out)
==43284==    by 0x4004C6: main (in /tmp/a.out)
==43284==  Address 0x4c1c068 is 0 bytes after a block of size 40 alloc'd
==43284==    at 0x4A05E1C: malloc (vg_replace_malloc.c:195)
==43284==    by 0x4004A9: f (in /tmp/a.out)
==43284==    by 0x4004C6: main (in /tmp/a.out)
==43284== 
==43284== 
==43284== HEAP SUMMARY:
==43284==     in use at exit: 40 bytes in 1 blocks
==43284==   total heap usage: 1 allocs, 0 frees, 40 bytes allocated
==43284== 
==43284== 40 bytes in 1 blocks are definitely lost in loss record 1 of 1
==43284==    at 0x4A05E1C: malloc (vg_replace_malloc.c:195)
==43284==    by 0x4004A9: f (in /tmp/a.out)
==43284==    by 0x4004C6: main (in /tmp/a.out)
==43284== 
==43284== LEAK SUMMARY:
==43284==    definitely lost: 40 bytes in 1 blocks
==43284==    indirectly lost: 0 bytes in 0 blocks
==43284==      possibly lost: 0 bytes in 0 blocks
==43284==    still reachable: 0 bytes in 0 blocks
==43284==         suppressed: 0 bytes in 0 blocks
==43284== 
==43284== For counts of detected and suppressed errors, rerun with: -v
==43284== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 4 from 4)

Name		Name	Last commit message	Last commit date
Latest commit History 5 Commits
binaries		binaries
examples		examples
source		source
tests		tests
Dockerfile		Dockerfile
README.md		README.md
READMEOLD.md		READMEOLD.md
docker-compose.yml		docker-compose.yml
es.subject_coRSair.pdf		es.subject_coRSair.pdf
notes.txt		notes.txt

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🔓 Corsair

📃 Table of contents

🔓 Corsair

📜 Introducción

📖 Instrucciones generales

❗ Parte Obligatoria

Ejercicio 1 - coRSAir

➕ Parte Bonus

🔐 My Corsair

❓ Corsair Help

📁 Files

👷 Build

Compile for distribution

Compile for Debugging

💧 Leaks

🎯 Tests

🔨 Use Examples

🔧 Software

GCC - GNU Compiler Collection

GDB

OpenSSL

Valgrind

👇 Useful Commands

GCC Commands

GDB Commands

OpenSSL Commands

Valgrind Commands

📌 Theory

📚 Sources

📑 Notes

📋 To Do

About

Releases

Packages

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OneProgrammerMore/Corsair_CyberSecurity42

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Repository files navigation

🔓 Corsair

📃 Table of contents

🔓 Corsair

📜 Introducción

📖 Instrucciones generales

❗ Parte Obligatoria

Ejercicio 1 - coRSAir

➕ Parte Bonus

🔐 My Corsair

❓ Corsair Help

📁 Files

👷 Build

Compile for distribution

Compile for Debugging

💧 Leaks

🎯 Tests

🔨 Use Examples

🔧 Software

GCC - GNU Compiler Collection

GDB

OpenSSL

Valgrind

👇 Useful Commands

GCC Commands

GDB Commands

OpenSSL Commands

Valgrind Commands

📌 Theory

📚 Sources

📑 Notes

📋 To Do

About

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