Skip to content

Fix decrypting exefs which encrypted via seed crypto #5

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
shijimasoft merged 1 commit into from
Mar 29, 2025
Merged

Fix decrypting exefs which encrypted via seed crypto #5

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 5 additions & 5 deletions src/main.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -97,7 +97,7 @@ fn scramblekey(key_x: u128, key_y: u128) -> u128 {
rol(value, 87)
}

fn dump_section(ncch: &mut File, cia: &mut CiaReader, offset: u64, size: u32, sec_type: NcchSection, sec_idx: usize, ctr: [u8; 16], uses_extra_crypto: u8, fixed_crypto: u8, encrypted: bool, keyys: [u128; 2]) {
fn dump_section(ncch: &mut File, cia: &mut CiaReader, offset: u64, size: u32, sec_type: NcchSection, sec_idx: usize, ctr: [u8; 16], uses_extra_crypto: u8, fixed_crypto: u8, use_seed_crypto: bool, encrypted: bool, keyys: [u128; 2]) {
let sections = ["ExHeader", "ExeFS", "RomFS"];
const CHUNK: u32 = 4194304; // 4 MiB
debug!(" {} offset: {:08X}", sections[sec_idx], offset);
Expand Down Expand Up @@ -163,7 +163,7 @@ fn dump_section(ncch: &mut File, cia: &mut CiaReader, offset: u64, size: u32, se
.unwrap()
.apply_keystream(&mut exetmp);

if flag_to_bool(uses_extra_crypto) {
if flag_to_bool(uses_extra_crypto) || use_seed_crypto {
let mut exetmp2 = exedata;
key = u128::to_be_bytes(scramblekey(KEYS_0[get_crypto_key(&uses_extra_crypto)], keyys[1]));

Expand Down Expand Up @@ -392,17 +392,17 @@ fn parse_ncch(cia: &mut CiaReader, offs: u64, mut titleid: [u8; 8]) {
let mut counter: [u8; 16];
if header.exhdrsize != 0 {
counter = get_ncch_aes_counter(&header, NcchSection::ExHeader);
dump_section(&mut ncch, cia, 512, header.exhdrsize * 2, NcchSection::ExHeader, 0, counter, uses_extra_crypto, fixed_crypto, encrypted, [ncch_key_y, key_y]);
dump_section(&mut ncch, cia, 512, header.exhdrsize * 2, NcchSection::ExHeader, 0, counter, uses_extra_crypto, fixed_crypto, use_seed_crypto, encrypted, [ncch_key_y, key_y]);
}

if header.exefssize != 0 {
counter = get_ncch_aes_counter(&header, NcchSection::ExeFS);
dump_section(&mut ncch, cia, (header.exefsoffset * MEDIA_UNIT_SIZE) as u64, header.exefssize * MEDIA_UNIT_SIZE, NcchSection::ExeFS, 1, counter, uses_extra_crypto, fixed_crypto, encrypted, [ncch_key_y, key_y]);
dump_section(&mut ncch, cia, (header.exefsoffset * MEDIA_UNIT_SIZE) as u64, header.exefssize * MEDIA_UNIT_SIZE, NcchSection::ExeFS, 1, counter, uses_extra_crypto, fixed_crypto, use_seed_crypto, encrypted, [ncch_key_y, key_y]);
}

if header.romfssize != 0 {
counter = get_ncch_aes_counter(&header, NcchSection::RomFS);
dump_section(&mut ncch, cia, (header.romfsoffset * MEDIA_UNIT_SIZE) as u64, header.romfssize * MEDIA_UNIT_SIZE, NcchSection::RomFS, 2, counter, uses_extra_crypto, fixed_crypto, encrypted, [ncch_key_y, key_y]);
dump_section(&mut ncch, cia, (header.romfsoffset * MEDIA_UNIT_SIZE) as u64, header.romfssize * MEDIA_UNIT_SIZE, NcchSection::RomFS, 2, counter, uses_extra_crypto, fixed_crypto, use_seed_crypto, encrypted, [ncch_key_y, key_y]);
}

info!("{}", base);
Expand Down