Files
vphone-cli/scripts/patchers/cfw_asm.py

209 lines
7.2 KiB
Python

"""Shared helpers for CFW patch modules."""
#!/usr/bin/env python3
"""
patch_cfw.py — Dynamic binary patching for CFW installation on vphone600.
Uses capstone for disassembly-based anchoring and keystone for instruction
assembly, producing reliable, upgrade-proof patches.
Called by install_cfw.sh during CFW installation.
Commands:
cryptex-paths <BuildManifest.plist>
Print SystemOS and AppOS DMG paths from BuildManifest.
patch-seputil <binary>
Patch seputil gigalocker UUID to "AA".
patch-launchd-cache-loader <binary>
NOP the cache validation check in launchd_cache_loader.
patch-mobileactivationd <binary>
Patch -[DeviceType should_hactivate] to always return true.
patch-launchd-jetsam <binary>
Patch launchd jetsam panic guard to avoid initproc crash loop.
inject-daemons <launchd.plist> <daemon_dir>
Inject bash/dropbear/trollvnc into launchd.plist.
inject-dylib <binary> <dylib_path>
Inject LC_LOAD_DYLIB into Mach-O binary (thin or universal).
Equivalent to: optool install -c load -p <dylib_path> -t <binary>
Dependencies:
pip install capstone keystone-engine
"""
import os
import plistlib
import struct
import subprocess
import sys
from capstone import Cs, CS_ARCH_ARM64, CS_MODE_LITTLE_ENDIAN
from capstone.arm64_const import ARM64_OP_IMM
from keystone import Ks, KS_ARCH_ARM64, KS_MODE_LITTLE_ENDIAN as KS_MODE_LE
# ══════════════════════════════════════════════════════════════════
# ARM64 assembler / disassembler
# ══════════════════════════════════════════════════════════════════
_cs = Cs(CS_ARCH_ARM64, CS_MODE_LITTLE_ENDIAN)
_cs.detail = True
_ks = Ks(KS_ARCH_ARM64, KS_MODE_LE)
def asm(s):
enc, _ = _ks.asm(s)
if not enc:
raise RuntimeError(f"asm failed: {s}")
return bytes(enc)
def asm_at(s, addr):
enc, _ = _ks.asm(s, addr=addr)
if not enc:
raise RuntimeError(f"asm failed at 0x{addr:X}: {s}")
return bytes(enc)
NOP = asm("nop")
MOV_X0_1 = asm("mov x0, #1")
RET = asm("ret")
def rd32(data, off):
return struct.unpack_from("<I", data, off)[0]
def wr32(data, off, val):
struct.pack_into("<I", data, off, val)
def disasm_at(data, off, n=8):
"""Disassemble n instructions at file offset."""
return list(_cs.disasm(bytes(data[off : off + n * 4]), off))
def _log_asm(data, offset, count=5, marker_off=-1):
"""Log disassembly of `count` instructions at file offset for before/after comparison."""
insns = disasm_at(data, offset, count)
for insn in insns:
tag = " >>>" if insn.address == marker_off else " "
print(f" {tag} 0x{insn.address:08X}: {insn.mnemonic:8s} {insn.op_str}")
# ══════════════════════════════════════════════════════════════════
# Mach-O helpers
# ══════════════════════════════════════════════════════════════════
def parse_macho_sections(data):
"""Parse Mach-O 64-bit to extract section info.
Returns dict: "segment,section" -> (vm_addr, size, file_offset)
"""
magic = struct.unpack_from("<I", data, 0)[0]
if magic != 0xFEEDFACF:
raise ValueError(f"Not a 64-bit Mach-O (magic=0x{magic:X})")
ncmds = struct.unpack_from("<I", data, 16)[0]
sections = {}
offset = 32 # sizeof(mach_header_64)
for _ in range(ncmds):
cmd, cmdsize = struct.unpack_from("<II", data, offset)
if cmd == 0x19: # LC_SEGMENT_64
segname = data[offset + 8 : offset + 24].split(b"\x00")[0].decode()
nsects = struct.unpack_from("<I", data, offset + 64)[0]
sect_off = offset + 72
for _ in range(nsects):
sectname = data[sect_off : sect_off + 16].split(b"\x00")[0].decode()
addr = struct.unpack_from("<Q", data, sect_off + 32)[0]
size = struct.unpack_from("<Q", data, sect_off + 40)[0]
file_off = struct.unpack_from("<I", data, sect_off + 48)[0]
sections[f"{segname},{sectname}"] = (addr, size, file_off)
sect_off += 80
offset += cmdsize
return sections
def va_to_foff(data, va):
"""Convert virtual address to file offset using LC_SEGMENT_64 commands."""
ncmds = struct.unpack_from("<I", data, 16)[0]
offset = 32
for _ in range(ncmds):
cmd, cmdsize = struct.unpack_from("<II", data, offset)
if cmd == 0x19: # LC_SEGMENT_64
vmaddr = struct.unpack_from("<Q", data, offset + 24)[0]
vmsize = struct.unpack_from("<Q", data, offset + 32)[0]
fileoff = struct.unpack_from("<Q", data, offset + 40)[0]
if vmaddr <= va < vmaddr + vmsize:
return fileoff + (va - vmaddr)
offset += cmdsize
return -1
def find_section(sections, *candidates):
"""Find the first matching section from candidates."""
for name in candidates:
if name in sections:
return sections[name]
return None
def find_symtab(data):
"""Parse LC_SYMTAB from Mach-O header.
Returns (symoff, nsyms, stroff, strsize) or None.
"""
ncmds = struct.unpack_from("<I", data, 16)[0]
offset = 32
for _ in range(ncmds):
cmd, cmdsize = struct.unpack_from("<II", data, offset)
if cmd == 0x02: # LC_SYMTAB
symoff = struct.unpack_from("<I", data, offset + 8)[0]
nsyms = struct.unpack_from("<I", data, offset + 12)[0]
stroff = struct.unpack_from("<I", data, offset + 16)[0]
strsize = struct.unpack_from("<I", data, offset + 20)[0]
return symoff, nsyms, stroff, strsize
offset += cmdsize
return None
def find_symbol_va(data, name_fragment):
"""Search Mach-O symbol table for a symbol containing name_fragment.
Returns the symbol's VA, or -1 if not found.
"""
st = find_symtab(data)
if not st:
return -1
symoff, nsyms, stroff, strsize = st
for i in range(nsyms):
entry_off = symoff + i * 16 # sizeof(nlist_64)
n_strx = struct.unpack_from("<I", data, entry_off)[0]
n_value = struct.unpack_from("<Q", data, entry_off + 8)[0]
if n_strx >= strsize or n_value == 0:
continue
# Read null-terminated symbol name
end = data.index(0, stroff + n_strx)
sym_name = data[stroff + n_strx : end].decode("ascii", errors="replace")
if name_fragment in sym_name:
return n_value
return -1
# ══════════════════════════════════════════════════════════════════
# 1. seputil — Gigalocker UUID patch
# ══════════════════════════════════════════════════════════════════