hacktricks/reversing/reversing-tools-basic-methods/angr/README.md

217 lines
11 KiB
Markdown

{% hint style="success" %}
Aprenda e pratique Hacking AWS:<img src="/.gitbook/assets/arte.png" alt="" data-size="line">[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)<img src="/.gitbook/assets/arte.png" alt="" data-size="line">\
Aprenda e pratique Hacking GCP: <img src="/.gitbook/assets/grte.png" alt="" data-size="line">[**HackTricks Training GCP Red Team Expert (GRTE)**<img src="/.gitbook/assets/grte.png" alt="" data-size="line">](https://training.hacktricks.xyz/courses/grte)
<details>
<summary>Suporte ao HackTricks</summary>
* Confira os [**planos de assinatura**](https://github.com/sponsors/carlospolop)!
* **Junte-se ao** 💬 [**grupo do Discord**](https://discord.gg/hRep4RUj7f) ou ao [**grupo do telegram**](https://t.me/peass) ou **siga**-nos no **Twitter** 🐦 [**@hacktricks\_live**](https://twitter.com/hacktricks\_live)**.**
* **Compartilhe truques de hacking enviando PRs para os repositórios do** [**HackTricks**](https://github.com/carlospolop/hacktricks) e [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud).
</details>
{% endhint %}
Parte deste cheatsheet é baseada na [documentação do angr](https://docs.angr.io/_/downloads/en/stable/pdf/).
# Instalação
```bash
sudo apt-get install python3-dev libffi-dev build-essential
python3 -m pip install --user virtualenv
python3 -m venv ang
source ang/bin/activate
pip install angr
```
# Ações Básicas
```python
import angr
import monkeyhex # this will format numerical results in hexadecimal
#Load binary
proj = angr.Project('/bin/true')
#BASIC BINARY DATA
proj.arch #Get arch "<Arch AMD64 (LE)>"
proj.arch.name #'AMD64'
proj.arch.memory_endness #'Iend_LE'
proj.entry #Get entrypoint "0x4023c0"
proj.filename #Get filename "/bin/true"
#There are specific options to load binaries
#Usually you won't need to use them but you could
angr.Project('examples/fauxware/fauxware', main_opts={'backend': 'blob', 'arch': 'i386'}, lib_opts={'libc.so.6': {'backend': 'elf'}})
```
# Informações sobre o objeto Carregado e Principal
## Dados Carregados
```python
#LOADED DATA
proj.loader #<Loaded true, maps [0x400000:0x5004000]>
proj.loader.min_addr #0x400000
proj.loader.max_addr #0x5004000
proj.loader.all_objects #All loaded
proj.loader.shared_objects #Loaded binaries
"""
OrderedDict([('true', <ELF Object true, maps [0x400000:0x40a377]>),
('libc.so.6',
<ELF Object libc-2.31.so, maps [0x500000:0x6c4507]>),
('ld-linux-x86-64.so.2',
<ELF Object ld-2.31.so, maps [0x700000:0x72c177]>),
('extern-address space',
<ExternObject Object cle##externs, maps [0x800000:0x87ffff]>),
('cle##tls',
<ELFTLSObjectV2 Object cle##tls, maps [0x900000:0x91500f]>)])
"""
proj.loader.all_elf_objects #Get all ELF objects loaded (Linux)
proj.loader.all_pe_objects #Get all binaries loaded (Windows)
proj.loader.find_object_containing(0x400000)#Get object loaded in an address "<ELF Object fauxware, maps [0x400000:0x60105f]>"
```
## Objeto Principal
```python
#Main Object (main binary loaded)
obj = proj.loader.main_object #<ELF Object true, maps [0x400000:0x60721f]>
obj.execstack #"False" Check for executable stack
obj.pic #"True" Check PIC
obj.imports #Get imports
obj.segments #<Regions: [<ELFSegment flags=0x5, relro=0x0, vaddr=0x400000, memsize=0xa74, filesize=0xa74, offset=0x0>, <ELFSegment flags=0x4, relro=0x1, vaddr=0x600e28, memsize=0x1d8, filesize=0x1d8, offset=0xe28>, <ELFSegment flags=0x6, relro=0x0, vaddr=0x601000, memsize=0x60, filesize=0x50, offset=0x1000>]>
obj.find_segment_containing(obj.entry) #Get segment by address
obj.sections #<Regions: [<Unnamed | offset 0x0, vaddr 0x0, size 0x0>, <.interp | offset 0x238, vaddr 0x400238, size 0x1c>, <.note.ABI-tag | offset 0x254, vaddr 0x400254, size 0x20>, <.note.gnu.build-id ...
obj.find_section_containing(obj.entry) #Get section by address
obj.plt['strcmp'] #Get plt address of a funcion (0x400550)
obj.reverse_plt[0x400550] #Get function from plt address ('strcmp')
```
## Símbolos e Realocações
```python
strcmp = proj.loader.find_symbol('strcmp') #<Symbol "strcmp" in libc.so.6 at 0x1089cd0>
strcmp.name #'strcmp'
strcmp.owne #<ELF Object libc-2.23.so, maps [0x1000000:0x13c999f]>
strcmp.rebased_addr #0x1089cd0
strcmp.linked_addr #0x89cd0
strcmp.relative_addr #0x89cd0
strcmp.is_export #True, as 'strcmp' is a function exported by libc
#Get strcmp from the main object
main_strcmp = proj.loader.main_object.get_symbol('strcmp')
main_strcmp.is_export #False
main_strcmp.is_import #True
main_strcmp.resolvedby #<Symbol "strcmp" in libc.so.6 at 0x1089cd0>
```
## Blocos
```python
#Blocks
block = proj.factory.block(proj.entry) #Get the block of the entrypoint fo the binary
block.pp() #Print disassembly of the block
block.instructions #"0xb" Get number of instructions
block.instruction_addrs #Get instructions addresses "[0x401670, 0x401672, 0x401675, 0x401676, 0x401679, 0x40167d, 0x40167e, 0x40167f, 0x401686, 0x40168d, 0x401694]"
```
# Análise Dinâmica
## Gerenciador de Simulação, Estados
```python
#Live States
#This is useful to modify content in a live analysis
state = proj.factory.entry_state()
state.regs.rip #Get the RIP
state.mem[proj.entry].int.resolved #Resolve as a C int (BV)
state.mem[proj.entry].int.concreteved #Resolve as python int
state.regs.rsi = state.solver.BVV(3, 64) #Modify RIP
state.mem[0x1000].long = 4 #Modify mem
#Other States
project.factory.entry_state()
project.factory.blank_state() #Most of its data left uninitialized
project.factory.full_init_statetate() #Execute through any initializers that need to be run before the main binary's entry point
project.factory.call_state() #Ready to execute a given function.
#Simulation manager
#The simulation manager stores all the states across the execution of the binary
simgr = proj.factory.simulation_manager(state) #Start
simgr.step() #Execute one step
simgr.active[0].regs.rip #Get RIP from the last state
```
## Chamando funções
* Você pode passar uma lista de argumentos através de `args` e um dicionário de variáveis de ambiente através de `env` para `entry_state` e `full_init_state`. Os valores nessas estruturas podem ser strings ou bitvectors, e serão serializados no estado como os argumentos e o ambiente para a execução simulada. O `args` padrão é uma lista vazia, então se o programa que você está analisando espera encontrar pelo menos um `argv[0]`, você deve sempre fornecer isso!
* Se você gostaria que `argc` fosse simbólico, pode passar um bitvector simbólico como `argc` para os construtores `entry_state` e `full_init_state`. Tenha cuidado, porém: se você fizer isso, também deve adicionar uma restrição ao estado resultante de que seu valor para argc não pode ser maior do que o número de args que você passou para `args`.
* Para usar o estado de chamada, você deve chamá-lo com `.call_state(addr, arg1, arg2, ...)`, onde `addr` é o endereço da função que você deseja chamar e `argN` é o N-ésimo argumento para essa função, seja como um inteiro python, string ou array, ou um bitvector. Se você quiser ter memória alocada e realmente passar um ponteiro para um objeto, deve envolvê-lo em um PointerWrapper, ou seja, `angr.PointerWrapper("point to me!")`. Os resultados desta API podem ser um pouco imprevisíveis, mas estamos trabalhando nisso.
## BitVectors
```python
#BitVectors
state = proj.factory.entry_state()
bv = state.solver.BVV(0x1234, 32) #Create BV of 32bits with the value "0x1234"
state.solver.eval(bv) #Convert BV to python int
bv.zero_extend(30) #Will add 30 zeros on the left of the bitvector
bv.sign_extend(30) #Will add 30 zeros or ones on the left of the BV extending the sign
```
## BitVectors Simbólicos & Restrições
```python
x = state.solver.BVS("x", 64) #Symbolic variable BV of length 64
y = state.solver.BVS("y", 64)
#Symbolic oprations
tree = (x + 1) / (y + 2)
tree #<BV64 (x_9_64 + 0x1) / (y_10_64 + 0x2)>
tree.op #'__floordiv__' Access last operation
tree.args #(<BV64 x_9_64 + 0x1>, <BV64 y_10_64 + 0x2>)
tree.args[0].op #'__add__' Access of dirst arg
tree.args[0].args #(<BV64 x_9_64>, <BV64 0x1>)
tree.args[0].args[1].op #'BVV'
tree.args[0].args[1].args #(1, 64)
#Symbolic constraints solver
state = proj.factory.entry_state() #Get a fresh state without constraints
input = state.solver.BVS('input', 64)
operation = (((input + 4) * 3) >> 1) + input
output = 200
state.solver.add(operation == output)
state.solver.eval(input) #0x3333333333333381
state.solver.add(input < 2**32)
state.satisfiable() #False
#Solver solutions
solver.eval(expression) #one possible solution
solver.eval_one(expression) #solution to the given expression, or throw an error if more than one solution is possible.
solver.eval_upto(expression, n) #n solutions to the given expression, returning fewer than n if fewer than n are possible.
solver.eval_atleast(expression, n) #n solutions to the given expression, throwing an error if fewer than n are possible.
solver.eval_exact(expression, n) #n solutions to the given expression, throwing an error if fewer or more than are possible.
solver.min(expression) #minimum possible solution to the given expression.
solver.max(expression) #maximum possible solution to the given expression.
```
## Hooking
```python
>>> stub_func = angr.SIM_PROCEDURES['stubs']['ReturnUnconstrained'] # this is a CLASS
>>> proj.hook(0x10000, stub_func()) # hook with an instance of the class
>>> proj.is_hooked(0x10000) # these functions should be pretty self-explanitory
True
>>> proj.hooked_by(0x10000)
<ReturnUnconstrained>
>>> proj.unhook(0x10000)
>>> @proj.hook(0x20000, length=5)
... def my_hook(state):
... state.regs.rax = 1
>>> proj.is_hooked(0x20000)
True
```
Além disso, você pode usar `proj.hook_symbol(name, hook)`, fornecendo o nome de um símbolo como o primeiro argumento, para conectar o endereço onde o símbolo reside.
# Exemplos
{% hint style="success" %}
Aprenda e pratique Hacking AWS:<img src="/.gitbook/assets/arte.png" alt="" data-size="line">[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)<img src="/.gitbook/assets/arte.png" alt="" data-size="line">\
Aprenda e pratique Hacking GCP: <img src="/.gitbook/assets/grte.png" alt="" data-size="line">[**HackTricks Training GCP Red Team Expert (GRTE)**<img src="/.gitbook/assets/grte.png" alt="" data-size="line">](https://training.hacktricks.xyz/courses/grte)
<details>
<summary>Support HackTricks</summary>
* Confira os [**planos de assinatura**](https://github.com/sponsors/carlospolop)!
* **Junte-se ao** 💬 [**grupo do Discord**](https://discord.gg/hRep4RUj7f) ou ao [**grupo do telegram**](https://t.me/peass) ou **siga**-nos no **Twitter** 🐦 [**@hacktricks\_live**](https://twitter.com/hacktricks\_live)**.**
* **Compartilhe truques de hacking enviando PRs para os repositórios do** [**HackTricks**](https://github.com/carlospolop/hacktricks) e [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud).
</details>
{% endhint %}