diff --git a/pkgs/discord-krisp/default.nix b/pkgs/discord-krisp/default.nix index 27cd1ccf3..7615b8d5c 100644 --- a/pkgs/discord-krisp/default.nix +++ b/pkgs/discord-krisp/default.nix @@ -1,19 +1,22 @@ { prev, ... }: let - patch-krisp = prev.writeScript "patch-krisp" '' - discord_version="${prev.discord.version}" - file="$HOME/.config/discord/$discord_version/modules/discord_krisp/discord_krisp.node" - if [ -f "$file" ]; then - addr=$("${prev.rizin}/bin/rz-find" -x '4881ec00010000' "$file" | head -n1) - "${prev.rizin}/bin/rizin" -q -w -c "s $addr + 0x30 ; wao nop" "$file" - fi - ''; + # krisp-patcher.py courtesy of https://github.com/sersorrel/sys + patch-krisp = prev.writers.writePython3 "krisp-patcher" { + libraries = with prev.python3Packages; [ capstone pyelftools ]; + # Ignore syntax checker error codes that affect krisp-patcher.py + flakeIgnore = [ + "E501" + "F403" + "F405" + ]; + } (builtins.readFile ./krisp-patcher.py); binaryName = "Discord"; + node_module="\\$HOME/.config/discord/${prev.discord.version}/modules/discord_krisp/discord_krisp.node"; in prev.discord.overrideAttrs (previousAttrs: { postInstall = previousAttrs.postInstall + '' wrapProgramShell $out/opt/${binaryName}/${binaryName} \ - --run "${patch-krisp}" + --run "${patch-krisp} ${node_module}" ''; passthru = removeAttrs previousAttrs.passthru [ "updateScript" ]; meta = { diff --git a/pkgs/discord-krisp/krisp-patcher.py b/pkgs/discord-krisp/krisp-patcher.py new file mode 100644 index 000000000..cf656dca3 --- /dev/null +++ b/pkgs/discord-krisp/krisp-patcher.py @@ -0,0 +1,93 @@ +# krisp-patcher.py courtesy of https://github.com/sersorrel/sys +import sys +import shutil + +from elftools.elf.elffile import ELFFile +from capstone import * +from capstone.x86 import * + +if len(sys.argv) < 2: + print(f"Usage: {sys.argv[0]} [path to discord_krisp.node]") + # "Unix programs generally use 2 for command line syntax errors and 1 for all other kind of errors." + exit() + +executable = sys.argv[1] + +elf: ELFFile + +try: + elf = ELFFile(open(executable, "rb")) +except FileNotFoundError: + print("Krisp executable could not be located. Skipping.") + exit() + +symtab = elf.get_section_by_name('.symtab') + +krisp_initialize_address = symtab.get_symbol_by_name("_ZN7discord15KrispInitializeEv")[0].entry.st_value +isSignedByDiscord_address = symtab.get_symbol_by_name("_ZN7discord4util17IsSignedByDiscordERKNSt4__Cr12basic_stringIcNS1_11char_traitsIcEENS1_9allocatorIcEEEE")[0].entry.st_value + +text = elf.get_section_by_name('.text') +text_start = text['sh_addr'] +text_start_file = text['sh_offset'] +# This seems to always be zero (.text starts at the right offset in the file). Do it just in case? +address_to_file = text_start_file - text_start + +# Done with the ELF now. +# elf.close() + +krisp_initialize_offset = krisp_initialize_address - address_to_file +isSignedByDiscord_offset = krisp_initialize_address - address_to_file + +f = open(executable, "rb") +f.seek(krisp_initialize_offset) +krisp_initialize = f.read(64) +f.close() + +# States +found_issigned_by_discord_call = False +found_issigned_by_discord_test = False +found_issigned_by_discord_je = False +found_already_patched = False +je_location = None +je_size = 0 + +# We are looking for a call to IsSignedByDiscord, followed by a test, followed by a je. +# Then we replace the je with nops. + +md = Cs(CS_ARCH_X86, CS_MODE_64) +md.detail = True +for i in md.disasm(krisp_initialize, krisp_initialize_address): + if i.id == X86_INS_CALL: + if i.operands[0].type == X86_OP_IMM: + if i.operands[0].imm == isSignedByDiscord_address: + found_issigned_by_discord_call = True + + if i.id == X86_INS_TEST: + if found_issigned_by_discord_call: + found_issigned_by_discord_test = True + + if i.id == X86_INS_JE: + if found_issigned_by_discord_test: + found_issigned_by_discord_je = True + je_location = i.address + je_size = len(i.bytes) + break + + if i.id == X86_INS_NOP: + if found_issigned_by_discord_test: + found_already_patched = True + break + +if je_location: + print(f"Found patch location: 0x{je_location:x}") + + shutil.copyfile(executable, executable + ".orig") + f = open(executable, 'rb+') + f.seek(je_location - address_to_file) + f.write(b'\x90' * je_size) # je can be larger than 2 bytes given a large enough displacement :( + f.close() +else: + if found_already_patched: + print("Couldn't find patch location - already patched.") + else: + print("Couldn't find patch location - review manually. Sorry.")