Updated README to reflect features since v0.5.0

* Unfinished wiiload module and LZ77 compression code

* Updated WIP LZ77 compressor, still not working yet

* Updated WIP LZ77 compressor, still not working yet (again)

* LZ77 compression is now fully functional! (But still very slow)

* Added compress_lz77 docstrings, temporarily removed unfinished wiiload module

README.md

@@ -2,7 +2,7 @@
 # libWiiPy
 libWiiPy is a modern Python 3 library for handling the various files and formats found on the Wii. It aims to be simple to use, well maintained, and offer as many features as reasonably possible in one library, so that a newly-written Python program could do 100% of its Wii-related work with just one library. It also aims to be fully cross-platform, so that any tools written with it can also be cross-platform.
 
-libWiiPy is inspired by [libWiiSharp](https://github.com/TheShadowEevee/libWiiSharp), which was originally created by `Leathl` and is now maintained by [@TheShadowEevee](https://github.com/TheShadowEevee). If you're looking for a Wii library that isn't in Python, then go check it out!
+libWiiPy is inspired by [libWiiSharp](https://github.com/TheShadowEevee/libWiiSharp), which was originally created by `Leathl` and is now maintained by [@TheShadowEevee](https://github.com/TheShadowEevee).
 
 
 # Features
@@ -10,14 +10,18 @@ This list will expand as libWiiPy is developed, but these features are currently
 - TMD and Ticket parsing/editing (`.tmd`, `.tik`)
 - Title parsing/editing, including content encryption/decryption (both retail and development)
 - WAD file parsing/editing (`.wad`)
-- Downloading titles from the NUS
+- Downloading titles and their components from the NUS
+- Certificate, TMD, and Ticket signature verification
 - Packing and unpacking U8 archives (`.app`, `.arc`)
 - Decompressing ASH files (`.ash`, both the standard variants and the variants found in My Pokémon Ranch)
+- Compressing/Decompressing LZ77-compressed files
 - IOS patching
 - NAND-related functionality:
   - EmuNAND title management (currently requires an existing EmuNAND)
   - `content.map` parsing/editing
+  - `setting.txt` parsing/editing
   - `uid.sys` parsing/editing
+- Limited channel banner parsing/editing
 - Assorted miscellaneous features used to make the other core features possible
 
 For a more detailed look at what's available in libWiiPy, check out our [API docs](https://ninjacheetah.github.io/libWiiPy).
@@ -68,6 +72,3 @@ Thank you to all of the contributors to the documentation on the WiiBrew pages t
 
 ### One additional special thanks to [@DamiDoop](https://github.com/DamiDoop)!
 She made the very cool banner you can see at the top of this README, and has also helped greatly with my sanity throughout debugging this library.
-
-**Note:** While libWiiPy is directly inspired by libWiiSharp and aims to have feature parity with it, no code from either libWiiSharp or Wii.py was used in the making of this library. All code is original and is written by [@NinjaCheetah](https://github.com/NinjaCheetah), [@rvtr](https://github.com/rvtr), and any other GitHub contributors.
-

docs/source/api.md

@@ -0,0 +1,23 @@
+# API Documentation
+
+libWiiPy is divided up into a few subpackages to organize related features.
+
+| Package                              | Description                                                     |
+|--------------------------------------|-----------------------------------------------------------------|
+| [libWiiPy.archive](/archive/archive) | Used to pack and extract archive formats used on the Wii        |
+| [libWiiPy.media](/media/media)       | Used for parsing and manipulating media formats used on the Wii |
+| [libWiiPy.nand](/nand/nand)          | Used for working with EmuNANDs and core system files on the Wii |
+| [libWiiPy.title](/title/title)       | Used for parsing and manipulating Wii titles                    |
+
+When using libWiiPy in your project, you can choose to either only import the package that you need, or you can use `import libWiiPy` to import the entire package, which each module being available at `libWiiPy.<package>.<module>`.
+
+## Full Package Contents
+
+```{toctree}
+:maxdepth: 8
+
+/archive/archive
+/media/media
+/nand/nand
+/title/title
+```

docs/source/archive/archive.md

@@ -0,0 +1,23 @@
+# libWiiPy.archive Package
+
+## Description
+
+The `libWiiPy.archive` package contains modules for packing and extracting archive formats used by the Wii. This currently includes packing and unpacking support for U8 archives and decompression support for ASH archives.
+
+## Modules
+
+| Module                                 | Description                                             |
+|----------------------------------------|---------------------------------------------------------|
+| [libWiiPy.archive.ash](/archive/ash)   | Provides support for decompressing ASH archives         |
+| [libWiiPy.archive.lz77](/archive/lz77) | Provides support for the LZ77 compression scheme        |
+| [libWiiPy.archive.u8](/archive/u8)     | Provides support for packing and extracting U8 archives |
+
+## Full Package Contents
+
+```{toctree}
+:maxdepth: 4
+
+/archive/ash
+/archive/lz77
+/archive/u8
+```

docs/source/archive/ash.md

@@ -0,0 +1,16 @@
+# libWiiPy.archive.ash Module
+
+## Description
+
+The `libWiiPy.archive.ash` module provides support for handling ASH files, which are a compressed format primarily used in the Wii Menu, but also in some other titles such as My Pokémon Ranch.
+
+At present, libWiiPy only has support for decompressing ASH files, with compression as a planned feature for the future.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.archive.ash
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/archive/lz77.md

@@ -0,0 +1,14 @@
+# libWiiPy.archive.lz77 Module
+
+## Description
+
+The `libWiiPy.archive.lz77` module provides support for handling LZ77 compression, which is a compression format used across the Wii and other Nintendo consoles.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.archive.lz77
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/archive/u8.md

@@ -0,0 +1,16 @@
+# libWiiPy.archive.u8 Module
+
+## Description
+
+The `libWiiPy.archive.u8` module provides support for handling U8 archives, which are a non-compressed archive format used extensively on the Wii to join multiple files into one.
+
+This module exposes functions for both packing and unpacking U8 archives, as well as code to parse IMET headers. IMET headers are a header format used specifically for U8 archives containing the banner of a channel, as they store the localized name of the channel along with other banner metadata.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.archive.u8
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/conf.py

@@ -11,6 +11,7 @@ from datetime import date
 project = 'libWiiPy'
 copyright = f'{date.today().year}, NinjaCheetah & Contributors'
 author = 'NinjaCheetah & Contributors'
+version = 'main'
 release = 'main'
 
 # -- General configuration ---------------------------------------------------
@@ -30,7 +31,8 @@ html_logo = "banner.png"
 html_title = "libWiiPy API Docs"
 html_theme_options = {
     "repository_url": "https://github.com/NinjaCheetah/libWiiPy",
-    "use_repository_button": True
+    "use_repository_button": True,
+    "show_toc_level": 3
 }
 
 # MyST Configuration

docs/source/index.md

@@ -4,9 +4,11 @@ sd_hide_title: true
 
 # Overview
 
-# libWiiPy API Docs
+# libWiiPy Documentation
 
-Welcome to the API documentation website for libWiiPy! libWiiPy is a modern Python 3 library for handling the various files and formats found on the Wii.
+Welcome to the documentation website for libWiiPy! libWiiPy is a modern Python 3 library for handling the various files and formats found on the Wii.
+
+Just need to see the API? [libWiiPy API Documentation](/api)
 
 ```{toctree}
 :hidden:
@@ -34,13 +36,12 @@ titles/nus-downloading.md
 
 ```{toctree}
 :hidden:
-:caption: Other Useful Pages
+:caption: More
 
-modules.md
+api.md
 ```
 
 ## Indices and tables
 
 * [Full Index](<project:#genindex>)
-* [Module Index](<project:#modules>)
 * <project:#search>

docs/source/libWiiPy.archive.md

@@ -1,28 +0,0 @@
-# libWiiPy.archive package
-
-## Submodules
-
-### libWiiPy.archive.ash module
-
-```{eval-rst}
-.. automodule:: libWiiPy.archive.ash
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-### libWiiPy.archive.u8 module
-
-```{eval-rst}
-.. automodule:: libWiiPy.archive.u8
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-## Module contents
-
-```{eval-rst}
-.. automodule:: libWiiPy.archive
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```

docs/source/libWiiPy.md

@@ -1,36 +0,0 @@
-# libWiiPy package
-
-## Subpackages
-
-```{toctree}
-:maxdepth: 4
-
-libWiiPy.archive
-libWiiPy.media
-libWiiPy.nand
-libWiiPy.title
-```
-
-## Submodules
-
-### libWiiPy.shared module
-
-libWiiPy's ``shared`` module is private and contains only private functions used by other modules.
-
-```{eval-rst}
-.. automodule:: libWiiPy.shared
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.types module
-
-libWiiPy's ``types`` module is private and contains only private classes used by other modules.
-
-```{eval-rst}
-.. automodule:: libWiiPy.types
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```

docs/source/libWiiPy.media.md

@@ -1,11 +0,0 @@
-# libWiiPy.media package
-
-## Submodules
-
-### libWiiPy.media.banner module
-```{eval-rst}
-.. automodule:: libWiiPy.media.banner
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```

docs/source/libWiiPy.nand.md

@@ -1,27 +0,0 @@
-# libWiiPy.nand package
-
-## Submodules
-
-### libWiiPy.nand.emunand module
-```{eval-rst}
-.. automodule:: libWiiPy.nand.emunand
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.nand.setting module
-```{eval-rst}
-.. automodule:: libWiiPy.nand.setting
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.nand.sys module
-```{eval-rst}
-.. automodule:: libWiiPy.nand.sys
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```

docs/source/libWiiPy.title.md

@@ -1,91 +0,0 @@
-# libWiiPy.title package
-
-## Submodules
-
-### libWiiPy.title.commonkeys module
-```{eval-rst}
-.. automodule:: libWiiPy.title.commonkeys
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.title.content module
-```{eval-rst}
-.. automodule:: libWiiPy.title.content
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.title.crypto module
-```{eval-rst}
-.. automodule:: libWiiPy.title.crypto
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiipy.title.iospatcher module
-```{eval-rst}
-.. automodule:: libWiiPy.title.iospatcher
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.title.nus module
-```{eval-rst}
-.. automodule:: libWiiPy.title.nus
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.title.ticket module
-```{eval-rst}
-.. automodule:: libWiiPy.title.ticket
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.title.title module
-```{eval-rst}
-.. automodule:: libWiiPy.title.title
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.title.tmd module
-```{eval-rst}
-.. automodule:: libWiiPy.title.tmd
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.title.util module
-```{eval-rst}
-.. automodule:: libWiiPy.title.util
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-### libWiiPy.title.wad module
-```{eval-rst}
-.. automodule:: libWiiPy.title.wad
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```
-
-## Module contents
-```{eval-rst}
-.. automodule:: libWiiPy.title
-   :members:
-   :undoc-members:
-   :show-inheritance:
-```

docs/source/media/banner.md

@@ -0,0 +1,14 @@
+# libWiiPy.media.banner Module
+
+## Description
+
+The `libWiiPy.media.banner` module is essentially a stub at this point in time. It only provides one dataclass that is likely to become a traditional class when fully implemented. It is not recommended to use this module for anything yet.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.media.banner
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/media/media.md

@@ -0,0 +1,19 @@
+# libWiiPy.media Package
+
+## Description
+
+The `libWiiPy.media` package contains modules used for parsing and editing media formats used by the Wii. This currently only includes limited support for parsing channel banners.
+
+## Modules
+
+| Module                                 | Description                                       |
+|----------------------------------------|---------------------------------------------------|
+| [libWiiPy.media.banner](/media/banner) | Provides support for basic channel banner parsing |
+
+## Full Package Contents
+
+```{toctree}
+:maxdepth: 4
+
+/media/banner
+```

docs/source/modules.md

@@ -1,7 +0,0 @@
-# Modules Overview
-
-```{toctree}
-:maxdepth: 4
-
-libWiiPy
-```

docs/source/nand/emunand.md

@@ -0,0 +1,14 @@
+# libWiiPy.nand.emunand Module
+
+## Description
+
+The `libWiiPy.nand.emunand` module provides support for creating and managing Wii EmuNANDs. At present, you cannot create an EmuNAND compatible with something like NEEK on a real Wii with the features provided by this library, but you can create an EmuNAND compatible with Dolphin.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.nand.emunand
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/nand/nand.md

@@ -0,0 +1,23 @@
+# libWiiPy.nand Package
+
+## Description
+
+The `libWiiPy.nand` package contains modules for parsing and manipulating EmuNANDs as well as modules for parsing and editing core system files found on the Wii's NAND.
+
+## Modules
+
+| Module                                 | Description                                                                                                                      |
+|----------------------------------------|----------------------------------------------------------------------------------------------------------------------------------|
+| [libWiiPy.nand.emunand](/nand/emunand) | Provides support for parsing, creating, and editing EmuNANDs                                                                     |
+| [libWiiPy.nand.setting](/nand/setting) | Provides support for parsing, creating, and editing `setting.txt`, which is used to store the console's region and serial number |
+| [libWiiPy.nand.sys](/nand/sys)         | Provides support for parsing, creating, and editing `uid.sys`, which is used to store a log of all titles run on a console       |
+
+## Full Package Contents
+
+```{toctree}
+:maxdepth: 4
+
+/nand/emunand
+/nand/setting
+/nand/sys
+```

docs/source/nand/setting.md

@@ -0,0 +1,16 @@
+# libWiiPy.nand.setting Module
+
+## Description
+
+The `libWiiPy.nand.setting` module provides support for handling the Wii's `setting.txt` file. This file is stored as part of the Wii Menu's save data (stored in `/title/00000001/00000002/data/`) and is an encrypted text file that's primarily used to store your console's serial number and region information.
+
+This module allows you to encrypt or decrypt this file, and exposes the keys stored in it for editing.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.nand.setting
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/nand/sys.md

@@ -0,0 +1,14 @@
+# libWiiPy.nand.sys Module
+
+## Description
+
+The `libWiiPy.nand.sys` module provides support for editing system files used on the Wii. Currently, it only offers support for `uid.sys`, which keeps a record of the Title IDs of every title launched on the console, assigning each one a unique ID.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.nand.sys
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/cert.md

@@ -0,0 +1,16 @@
+# libWiiPy.title.cert Module
+
+## Description
+
+The `libWiiPy.title.cert` module provides support for parsing the various signing certificates used by the Wii for content validation.
+
+This module allows you to write your own code for validating the authenticity of a TMD or Ticket by providing the certificates from the Wii's certificate chain. Both retail and development certificate chains are supported.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.cert
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/commonkeys.md

@@ -0,0 +1,14 @@
+# libWiiPy.title.commonkeys Module
+
+## Description
+
+The `libWiiPy.title.commonkeys` module simply provides easy access to the Wii's common encryption keys.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.commonkeys
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/content.md

@@ -0,0 +1,14 @@
+# libWiiPy.title.content Module
+
+## Description
+
+The `libWiiPy.title.content` module provides support for parsing, adding, removing, and editing content files from a digital Wii title.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.content
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/crypto.md

@@ -0,0 +1,14 @@
+# libWiiPy.title.crypto Module
+
+## Description
+
+The `libWiiPy.title.crypto` module provides low-level cryptography functions required for handling digital Wii titles. It does not expose many functions that are likely to be required during typical use, and instead acts more as a dependency for other modules.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.crypto
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/iospatcher.md

@@ -0,0 +1,14 @@
+# libWiiPy.title.iospatcher Module
+
+## Description
+
+The `libWiiPy.title.iospatcher` module provides support for applying various binary patches to IOS' ES module. These patches and what they do can be found attached to the methods used to apply them.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.iospatcher
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/nus.md

@@ -0,0 +1,14 @@
+# libWiiPy.title.nus Module
+
+## Description
+
+The `libWiiPy.title.nus` module provides support for downloading digital Wii titles from the Nintendo Update Servers. This module provides easy methods for downloading TMDs, common Tickets (when present), encrypted content, and the certificate chain.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.nus
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/ticket.md

@@ -0,0 +1,14 @@
+# libWiiPy.title.ticket Module
+
+## Description
+
+The `libWiiPy.title.ticket` module provides support for handling Tickets, which are the license files used to decrypt the content of digital titles during installation. This module allows for easy parsing and editing of Tickets.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.ticket
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/title.md

@@ -0,0 +1,38 @@
+# libWiiPy.title Package
+
+## Description
+The `libWiiPy.title` package contains modules for interacting with Wii titles. This is the most complete package in libWiiPy, as it offers the functionality one would be most likely to need. As a result, it gets the most attention during development and should be the most reliable.
+
+## Modules
+
+| Module                                         | Description                                                                                                                   |
+|------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------|
+| [libWiiPy.title.cert](/title/cert)             | Provides support for parsing and validating the certificates used for title verification                                      |
+| [libWiiPy.title.commonkeys](/title/commonkeys) | Provides easy access to all common encryption keys                                                                            |
+| [libWiiPy.title.content](/title/content)       | Provides support for parsing and editing content included as part of digital titles                                           |
+| [libWiiPy.title.crypto](/title/crypto)         | Provides low-level cryptography functions used to handle encryption in other modules                                          |
+| [libWiiPy.title.iospatcher](/title/iospatcher) | Provides an easy interface to apply patches to IOSes                                                                          |
+| [libWiiPy.title.nus](/title/nus)               | Provides support for downloading TMDs, Tickets, encrypted content, and the certificate chain from the Nintendo Update Servers |
+| [libWiiPy.title.ticket](/title/ticket)         | Provides support for parsing and editing Tickets used for content decryption                                                  |
+| [libWiiPy.title.title](/title/title.title)     | Provides high-level support for parsing and editing an entire title with the context of each component                        |
+| [libWiiPy.title.tmd](/title/tmd)               | Provides support for parsing and editing TMDs (Title Metadata)                                                                |
+| [libWiiPy.title.util](/title/util)             | Provides some simple utility functions relating to titles                                                                     |
+| [libWiiPy.title.wad](/title/wad)               | Provides support for parsing and editing WAD files, allowing you to load each component into the other available classes      |
+
+## Full Package Contents
+
+```{toctree}
+:maxdepth: 4
+
+/title/cert
+/title/commonkeys
+/title/content
+/title/crypto
+/title/iospatcher
+/title/nus
+/title/ticket
+/title/title.title
+/title/tmd
+/title/util
+/title/wad
+```

docs/source/title/title.title.md

@@ -0,0 +1,17 @@
+# libWiiPy.title.title Module
+
+## Description
+
+The `libWiiPy.title.title` module provides a high-level interface for handling all the components of a digital Wii title through one class. It allows for directly importing a WAD, and will automatically extract the various components and load them into their appropriate classes. Additionally, it provides duplicates of some methods found in those classes that require fewer arguments, as it has the context of the other components and is able to retrieve additional data automatically.
+
+An example of that idea can be seen with the method `get_content_by_index()`. In its original definition, which can be seen at <project:#libWiiPy.title.content.ContentRegion.get_content_by_index>, you are required to supply the Title Key for the title that the content is sourced from. In contrast, when using <project:#libWiiPy.title.title.Title.get_content_by_index>, you do not need to supply a Title Key, as the Title object already has the context of the Ticket and can retrieve the Title Key from it automatically. In a similar vein, this module provides the easiest route for verifying that a title is legitimately signed by Nintendo. The method <project:#libWiiPy.title.title.Title.get_is_signed> is able to access the entire certificate chain, the TMD, and the Ticket, and is therefore able to verify all components of the title by itself.
+
+Because using <project:#libWiiPy.title.title.Title> allows many operations to be much simpler than if you manage the components separately, it's generally recommended to use it whenever possible.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.title
+   :members:
+   :undoc-members:
+```

docs/source/title/tmd.md

@@ -0,0 +1,14 @@
+# libWiiPy.title.tmd Module
+
+## Description
+
+The `libWiiPy.title.tmd` module provides support for handling TMD (Title Metadata) files, which contain the metadata of both digital and physical Wii titles. This module allows for easy parsing and editing of TMDs.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.tmd
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/util.md

@@ -0,0 +1,14 @@
+# libWiiPy.title.util Module
+
+## Description
+
+The `libWiiPy.title.util` module provides common utility functions internally. It is not designed to be used directly.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.util
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/title/wad.md

@@ -0,0 +1,14 @@
+# libWiiPy.title.wad Module
+
+## Description
+
+The `libWiiPy.title.wad` module provides support for handling WAD (Wii Archive Data) files, which is the format used to deliver digital Wii titles. This module allows for extracting the various components for a WAD, as well as properly padding and writing out that data when it has been edited using other modules.
+
+## Module Contents
+
+```{eval-rst}
+.. automodule:: libWiiPy.title.wad
+   :members:
+   :undoc-members:
+   :show-inheritance:
+```

docs/source/titles/extracting-titles.md

@@ -34,7 +34,7 @@ And viola! We have a WAD object that we can use to get each separate part of our
 
 ## Picking the WAD Apart
 
-Now that we have our WAD loaded, we need to separate it out into its components. On top of the parts we already established, a WAD also contains a certificate, checked by IOS during official title installations to ensure that a title was signed by Nintendo, and potentially two more areas called the footer and the CRL. Footers aren't a necessary part of a WAD, and when they do exist, they typically only contain the build timestamp and the machine it was built on. CRLs are even less common, and have never actually been found inside any WAD, but we know they exist because of things we've seen that Nintendo would really rather we hadn't. Because these three components don't have data we can edit, they're only ever represented as bytes, and do not have their own classes.
+Now that we have our WAD loaded, we need to separate it out into its components. On top of the parts we already established, a WAD also contains a certificate chain, which is used by IOS during official title installations to ensure that a title was signed by Nintendo, and potentially two more areas called the footer and the CRL. Footers aren't a necessary part of a WAD, and when they do exist, they typically only contain the build timestamp and the machine it was built on. CRLs are even less common, and have never actually been found inside any WAD, but we know they exist because of things we've seen that Nintendo would really rather we hadn't. Certificate chains also have a class that we'll cover after the main three components, but the latter two components don't have data we can edit, so they're only ever represented as bytes and do not have their own classes.
 
 ### The TMD
 
@@ -110,11 +110,19 @@ Now that we know things are working, why don't we speed things up a little by us
 
 And just like that, we have our TMD, Ticket, and decrypted content all extracted! From here, what you do with them is up to you and whatever program you're working on. For example, to make a simple WAD extractor, you may want to write all these files to an output directory.
 
+### The Certificate Chain
+
+As mentioned at the start of this guide, WADs also contain a certificate chain. We don't necessarily need this data right now, but getting it is very similar to the other components:
+```pycon
+>>> certificate_chain = libWiiPy.title.CertificateChain()
+>>> certificate_chain.load(wad.get_cert_data())
+>>>
+```
+
 ### The Other Data
 
-As mentioned earlier in this guide, WADs also contain up to three extra regions of data: the certificate, the footer, and the CRL. The procedure for extracting all of these is pretty simple, and follows the same formula as any other data in a WAD:
+Also mentioned earlier in this guide, WADs may contain two additional regions of data know as the footer (or "meta"), and the CRL. The procedure for extracting all of these is pretty simple, and follows the same formula as any other data in a WAD:
 ```pycon
->>> certificate = wad.get_cert_data()
 >>> footer = wad.get_meta_data()
 >>> crl = wad.get_crl_data()
 >>>
@@ -123,7 +131,7 @@ As mentioned earlier in this guide, WADs also contain up to three extra regions
 Beyond getting their raw data, there isn't anything you can directly do with these components with libWiiPy. If one of these components doesn't exist, libWiiPy will simply return an empty bytes object.
 
 :::{note}
-Managed to find a WAD somewhere with CRL data? I'd love to here more, so feel free to email me at [ninjacheetah@ncxprogramming.com](mailto:ninjacheetah@ncxprogramming.com).
+Managed to find a WAD somewhere with CRL data? I'd love to hear more, so feel free to email me at [ninjacheetah@ncxprogramming.com](mailto:ninjacheetah@ncxprogramming.com).
 :::
 
 <hr>

src/libWiiPy/archive/__init__.py

@@ -2,4 +2,5 @@
 # https://github.com/NinjaCheetah/libWiiPy
 
 from .ash import *
+from .lz77 import *
 from .u8 import *

src/libWiiPy/archive/ash.py

@@ -5,7 +5,7 @@
 # co-authored by NinjaCheetah.
 # https://github.com/NinjaCheetah/ASH0-tools
 #
-# See <link pending> for details about the ASH archive format.
+# See <link pending> for details about the ASH compression format.
 
 import io
 from dataclasses import dataclass as _dataclass

src/libWiiPy/archive/lz77.py

@@ -0,0 +1,291 @@
+# "archive/lz77.py" from libWiiPy by NinjaCheetah & Contributors
+# https://github.com/NinjaCheetah/libWiiPy
+#
+# See https://wiibrew.org/wiki/LZ77 for details about the LZ77 compression format.
+
+import io
+from dataclasses import dataclass as _dataclass
+from typing import List as _List
+
+
+_LZ_MIN_DISTANCE = 0x01   # Minimum distance for each reference.
+_LZ_MAX_DISTANCE = 0x1000   # Maximum distance for each reference.
+_LZ_MIN_LENGTH = 0x03   # Minimum length for each reference.
+_LZ_MAX_LENGTH = 0x12   # Maximum length for each reference.
+
+
+@_dataclass
+class _LZNode:
+    dist: int = 0
+    len: int = 0
+    weight: int = 0
+
+
+def _compress_compare_bytes(buffer: _List[int], offset1: int, offset2: int, abs_len_max: int) -> int:
+    # Compare bytes up to the maximum length we can match. Start by comparing the first 3 bytes, since that's the
+    # minimum match length and this allows for a more optimized early exit.
+    num_matched = 0
+    while num_matched < abs_len_max:
+        if buffer[offset1 + num_matched] != buffer[offset2 + num_matched]:
+            break
+        num_matched += 1
+    return num_matched
+
+
+def _compress_search_matches_optimized(buffer: _List[int], pos: int) -> (int, int):
+    bytes_left = len(buffer) - pos
+    global _LZ_MAX_DISTANCE, _LZ_MIN_LENGTH, _LZ_MAX_LENGTH, _LZ_MIN_DISTANCE
+    # Default to only looking back 4096 bytes, unless we've moved fewer than 4096 bytes, in which case we should
+    # only look as far back as we've gone.
+    max_dist = min(_LZ_MAX_DISTANCE, pos)
+    # Default to only matching up to 18 bytes, unless fewer than 18 bytes remain, in which case we can only match
+    # up to that many bytes.
+    max_len = min(_LZ_MAX_LENGTH, bytes_left)
+    # Log the longest match we found and its offset.
+    biggest_match, biggest_match_pos = 0, 0
+    # Search for matches.
+    for i in range(_LZ_MIN_DISTANCE, max_dist + 1):
+        num_matched = _compress_compare_bytes(buffer, pos - i, pos, max_len)
+        if num_matched > biggest_match:
+            biggest_match = num_matched
+            biggest_match_pos = i
+            if biggest_match == max_len:
+                break
+    return biggest_match, biggest_match_pos
+
+
+def _compress_search_matches_greedy(buffer: _List[int], pos: int) -> (int, int):
+    # Finds and returns the first valid match, rather that finding the best one.
+    bytes_left = len(buffer) - pos
+    global _LZ_MAX_DISTANCE, _LZ_MAX_LENGTH, _LZ_MIN_DISTANCE
+    # Default to only looking back 4096 bytes, unless we've moved fewer than 4096 bytes, in which case we should
+    # only look as far back as we've gone.
+    max_dist = min(_LZ_MAX_DISTANCE, pos)
+    # Default to only matching up to 18 bytes, unless fewer than 18 bytes remain, in which case we can only match
+    # up to that many bytes.
+    max_len = min(_LZ_MAX_LENGTH, bytes_left)
+    match, match_pos = 0, 0
+    for i in range(_LZ_MIN_DISTANCE, max_dist + 1):
+        match = _compress_compare_bytes(buffer, pos - i, pos, max_len)
+        match_pos = i
+        if match >= _LZ_MIN_LENGTH or match == max_len:
+            break
+    return match, match_pos
+
+
+def _compress_node_is_ref(node: _LZNode) -> bool:
+    return node.len >= _LZ_MIN_LENGTH
+
+
+def _compress_get_node_cost(length: int) -> int:
+    if length >= _LZ_MIN_LENGTH:
+        num_bytes = 2
+    else:
+        num_bytes = 1
+    return 1 + (num_bytes * 8)
+
+
+def _compress_lz77_optimized(data: bytes) -> bytes:
+    # Optimized compressor based around a node graph that finds optimal string matches. Originally the default
+    # implementation, but unfortunately it's very slow.
+    nodes = [_LZNode() for _ in range(len(data))]
+    # Iterate over the uncompressed data, starting from the end.
+    pos = len(data)
+    global _LZ_MAX_LENGTH, _LZ_MIN_LENGTH, _LZ_MIN_DISTANCE
+    data_list = list(data)
+    while pos:
+        pos -= 1
+        node = nodes[pos]
+        # Limit the maximum search length when we're near the end of the file.
+        max_search_len = min(_LZ_MAX_LENGTH, len(data_list) - pos)
+        if max_search_len < _LZ_MIN_DISTANCE:
+            max_search_len = 1
+        # Initialize as 1 for each, since that's all we could use if we weren't compressing.
+        length, dist = 1, 1
+        if max_search_len >= _LZ_MIN_LENGTH:
+            length, dist = _compress_search_matches_optimized(data_list, pos)
+        # Treat as direct bytes if it's too short to copy.
+        if length == 0 or length < _LZ_MIN_LENGTH:
+            length = 1
+        # If the node goes to the end of the file, the weight is the cost of the node.
+        if (pos + length) == len(data_list):
+            node.len = length
+            node.dist = dist
+            node.weight = _compress_get_node_cost(length)
+        # Otherwise, search for possible matches and determine the one with the best cost.
+        else:
+            weight_best = 0xFFFFFFFF  # This was originally UINT_MAX, but that isn't a thing here so 32-bit it is!
+            len_best = 1
+            while length:
+                weight_next = nodes[pos + length].weight
+                weight = _compress_get_node_cost(length) + weight_next
+                if weight < weight_best:
+                    len_best = length
+                    weight_best = weight
+                length -= 1
+                if length != 0 and length < _LZ_MIN_LENGTH:
+                    length = 1
+            node.len = len_best
+            node.dist = dist
+            node.weight = weight_best
+    # Write the compressed data.
+    with io.BytesIO() as buffer:
+        # Write the header data.
+        buffer.write(b'LZ77\x10')  # The LZ type on the Wii is *always* 0x10.
+        buffer.write(len(data).to_bytes(3, 'little'))
+
+        src_pos = 0
+        while src_pos < len(data):
+            head = 0
+            head_pos = buffer.tell()
+            buffer.write(b'\x00')  # Reserve a byte for the chunk head.
+
+            i = 0
+            while i < 8 and src_pos < len(data):
+                current_node = nodes[src_pos]
+                length = current_node.len
+                dist = current_node.dist
+                # This is a reference node.
+                if _compress_node_is_ref(current_node):
+                    encoded = (((length - _LZ_MIN_LENGTH) & 0xF) << 12) | ((dist - _LZ_MIN_DISTANCE) & 0xFFF)
+                    buffer.write(encoded.to_bytes(2))
+                    head = (head | (1 << (7 - i))) & 0xFF
+                # This is a direct copy node.
+                else:
+                    buffer.write(data[src_pos:src_pos + 1])
+                src_pos += length
+                i += 1
+
+            pos = buffer.tell()
+            buffer.seek(head_pos)
+            buffer.write(head.to_bytes(1))
+            buffer.seek(pos)
+
+        buffer.seek(0)
+        out_data = buffer.read()
+    return out_data
+
+
+def _compress_lz77_greedy(data: bytes) -> bytes:
+    # Greedy compressor that processes the file start to end and saves the first matches found. Faster than the
+    # optimized implementation, but creates larger files.
+    global _LZ_MAX_LENGTH, _LZ_MIN_LENGTH, _LZ_MIN_DISTANCE
+    with io.BytesIO() as buffer:
+        # Write the header data.
+        buffer.write(b'LZ77\x10')  # The LZ type on the Wii is *always* 0x10.
+        buffer.write(len(data).to_bytes(3, 'little'))
+
+        src_pos = 0
+        data_list = list(data)
+        while src_pos < len(data):
+            head = 0
+            head_pos = buffer.tell()
+            buffer.write(b'\x00')  # Reserve a byte for the chunk head.
+
+            i = 0
+            while i < 8 and src_pos < len(data):
+                length, dist = _compress_search_matches_greedy(data_list, src_pos)
+                # This is a reference node.
+                if length >= _LZ_MIN_LENGTH:
+                    encoded = (((length - _LZ_MIN_LENGTH) & 0xF) << 12) | ((dist - _LZ_MIN_DISTANCE) & 0xFFF)
+                    buffer.write(encoded.to_bytes(2))
+                    head = (head | (1 << (7 - i))) & 0xFF
+                    src_pos += length
+                # This is a direct copy node.
+                else:
+                    buffer.write(data[src_pos:src_pos + 1])
+                    src_pos += 1
+                i += 1
+
+            pos = buffer.tell()
+            buffer.seek(head_pos)
+            buffer.write(head.to_bytes(1))
+            buffer.seek(pos)
+
+        buffer.seek(0)
+        out_data = buffer.read()
+    return out_data
+
+
+def compress_lz77(data: bytes, compression_level: int = 1) -> bytes:
+    """
+    Compresses data using the Wii's LZ77 compression algorithm and returns the compressed result. Supports two
+    different levels of compression, one based around a "greedy" LZ compression algorithm and the other based around
+    an optimized LZ compression algorithm. The greedy compressor, level 1, will produce a larger compressed file but
+    will run noticeably faster than the optimized compressor, which is level 2, especially for larger data.
+
+    Parameters
+    ----------
+    data: bytes
+        The data to compress.
+    compression_level: int
+        The compression level to use, either 1 and 2. Default value is 1.
+
+    Returns
+    -------
+    bytes
+        The LZ77-compressed data.
+    """
+    if compression_level == 1:
+        out_data = _compress_lz77_greedy(data)
+    elif compression_level == 2:
+        out_data = _compress_lz77_optimized(data)
+    else:
+        raise ValueError(f"Invalid compression level \"{compression_level}\"!\"")
+    return out_data
+
+
+def decompress_lz77(lz77_data: bytes) -> bytes:
+    """
+    Decompresses LZ77-compressed data and returns the decompressed result. Supports data both with and without the
+    magic number 'LZ77' (which may not be present if the data is embedded in something else).
+
+    Parameters
+    ----------
+    lz77_data: bytes
+        The LZ77-compressed data to decompress.
+
+    Returns
+    -------
+    bytes
+        The decompressed data.
+    """
+    with io.BytesIO(lz77_data) as data:
+        magic = data.read(4)
+        # Assume if we didn't get the magic number that this data starts without it.
+        if magic != b'LZ77':
+            data.seek(0)
+        # Other compression types are used by Nintendo, but only type 0x10 was used on the Wii.
+        compression_type = int.from_bytes(data.read(1))
+        if compression_type != 0x10:
+            raise ValueError("This data is using an unsupported compression type!")
+        decompressed_size = int.from_bytes(data.read(3), byteorder='little')
+        # Use an integer list for storing decompressed data, this is much faster than using (and appending to) a
+        # bytes object.
+        out_data = [0] * decompressed_size
+        pos = 0
+        while pos < decompressed_size:
+            flag = int.from_bytes(data.read(1))
+            # Read bits in the flag from most to least significant.
+            for x in range(7, -1, -1):
+                # Avoids a buffer overrun if the final flag isn't fully used.
+                if pos >= decompressed_size:
+                    break
+                # Result of 1, this means we're copying bytes from earlier in the data.
+                if flag & (1 << x):
+                    reference = int.from_bytes(data.read(2))
+                    length = 3 + ((reference >> 12) & 0xF)
+                    offset = pos - (reference & 0xFFF) - 1
+                    for _ in range(length):
+                        out_data[pos] = out_data[offset]
+                        pos += 1
+                        offset += 1
+                        # Avoids a buffer overrun if the copy length would extend past the end of the file.
+                        if pos >= decompressed_size:
+                            break
+                # Result of 0, use the next byte directly.
+                else:
+                    out_data[pos] = int.from_bytes(data.read(1))
+                    pos += 1
+        out_bytes = bytes(out_data)
+        return out_bytes

src/libWiiPy/nand/emunand.py

@@ -199,8 +199,8 @@ class EmuNAND:
             valid_lows = []
             for low in tid_lows:
                 if low.joinpath("content", "title.tmd").exists():
-                    valid_lows.append(low.name)
+                    valid_lows.append(low.name.upper())
-            installed_titles.append(self.InstalledTitles(high.name, valid_lows))
+            installed_titles.append(self.InstalledTitles(high.name.upper(), valid_lows))
         return installed_titles
 
     def get_title_tmd(self, tid: str) -> TMD:

src/libWiiPy/title/__init__.py

@@ -1,6 +1,7 @@
 # "title/__init__.py" from libWiiPy by NinjaCheetah & Contributors
 # https://github.com/NinjaCheetah/libWiiPy
 
+from .cert import *
 from .content import *
 from .crypto import *
 from .iospatcher import *

src/libWiiPy/title/cert.py

@@ -0,0 +1,362 @@
+# "title/cert.py" from libWiiPy by NinjaCheetah & Contributors
+# https://github.com/NinjaCheetah/libWiiPy
+#
+# See https://wiibrew.org/wiki/Certificate_chain for details about the Wii's certificate chain
+
+import io
+from enum import IntEnum as _IntEnum
+from ..shared import _align_value, _pad_bytes
+from .ticket import Ticket
+from .tmd import TMD
+from Crypto.Hash import SHA1
+from Crypto.PublicKey import RSA
+from Crypto.Signature import pkcs1_15
+
+
+class CertificateType(_IntEnum):
+    RSA_4096 = 0x00010000
+    RSA_2048 = 0x00010001
+    ECC = 0x00010002
+
+
+class CertificateSignatureLength(_IntEnum):
+    RSA_4096 = 0x200
+    RSA_2048 = 0x100
+    ECC = 0x3C
+
+
+class CertificateKeyType(_IntEnum):
+    RSA_4096 = 0x00000000
+    RSA_2048 = 0x00000001
+    ECC = 0x00000002
+
+
+class CertificateKeyLength(_IntEnum):
+    RSA_4096 = 0x200
+    RSA_2048 = 0x100
+    ECC = 0x3C
+
+
+class Certificate:
+    """
+    A Certificate object used to parse a certificate used for the Wii's content verification.
+
+    Attributes
+    ----------
+    type: CertificateType
+        The type of the certificate, either RSA-2048, RSA-4096, or ECC.
+    signature: bytes
+        The signature data of the certificate.
+    issuer: str
+        The certificate that issued this certificate.
+    pub_key_type: CertificateKeyType
+        The type of public key contained in the certificate, either RSA-2048, RSA-4096, or ECC.
+    child_name: str
+        The name of this certificate.
+    pub_key_id: int
+        The ID of this certificate's public key.
+    pub_key_modulus: int
+        The modulus of this certificate's public key. Combined with the exponent to get the full key.
+    pub_key_exponent: int
+        The exponent of this certificate's public key. Combined with the modulus to get the full key.
+    """
+    def __init__(self):
+        self.type: CertificateType | None = None
+        self.signature: bytes = b''
+        self.issuer: str = ""
+        self.pub_key_type: CertificateKeyType | None = None
+        self.child_name: str = ""
+        self.pub_key_id: int = 0
+        self.pub_key_modulus: int = 0
+        self.pub_key_exponent: int = 0
+
+    def load(self, cert: bytes) -> None:
+        """
+        Loads certificate data into the Certificate object, allowing you to parse the certificate.
+
+        Parameters
+        ----------
+        cert: bytes
+            The data for the certificate to load.
+        """
+        with io.BytesIO(cert) as cert_data:
+            # Read the first 4 bytes of the cert to get the certificate's type.
+            try:
+                self.type = CertificateType.from_bytes(cert_data.read(0x4))
+            except ValueError:
+                raise ValueError("Invalid Certificate Type!")
+            cert_length = CertificateSignatureLength[self.type.name]
+            self.signature = cert_data.read(cert_length.value)
+            cert_data.seek(0x40 + cert_length.value)
+            self.issuer = str(cert_data.read(0x40).replace(b'\x00', b'').decode())
+            try:
+                cert_data.seek(0x80 + cert_length.value)
+                self.pub_key_type = CertificateKeyType.from_bytes(cert_data.read(0x4))
+            except ValueError:
+                raise ValueError("Invalid Certificate Key type!")
+            cert_data.seek(0x84 + cert_length.value)
+            self.child_name = str(cert_data.read(0x40).replace(b'\x00', b'').decode())
+            cert_data.seek(0xC4 + cert_length.value)
+            self.pub_key_id = int.from_bytes(cert_data.read(0x4))
+            key_length = CertificateKeyLength[self.pub_key_type.name]
+            cert_data.seek(0xC8 + cert_length.value)
+            self.pub_key_modulus = int.from_bytes(cert_data.read(key_length.value))
+            if self.pub_key_type == CertificateKeyType.RSA_4096 or self.pub_key_type == CertificateKeyType.RSA_2048:
+                self.pub_key_exponent = int.from_bytes(cert_data.read(0x4))
+
+    def dump(self) -> bytes:
+        """
+        Dump the certificate object back into bytes.
+
+        Returns
+        -------
+        bytes:
+            The certificate file as bytes.
+        """
+        cert_data = b''
+        cert_data += int.to_bytes(self.type.value, 4)
+        cert_data += self.signature
+        cert_data = _pad_bytes(cert_data)
+        # Pad out the issuer name with null bytes.
+        issuer = self.issuer.encode()
+        while len(issuer) < 0x40:
+            issuer += b'\x00'
+        cert_data += issuer
+        cert_data += int.to_bytes(self.pub_key_type.value, 4)
+        # Pad out the child cert name with null bytes
+        child_name = self.child_name.encode()
+        while len(child_name) < 0x40:
+            child_name += b'\x00'
+        cert_data += child_name
+        cert_data += int.to_bytes(self.pub_key_id, 4)
+        cert_data += int.to_bytes(self.pub_key_modulus, CertificateKeyLength[self.pub_key_type.name])
+        if self.pub_key_type == CertificateKeyType.RSA_4096 or self.pub_key_type == CertificateKeyType.RSA_2048:
+            cert_data += int.to_bytes(self.pub_key_exponent, 4)
+        # Pad out the certificate data to a multiple of 64.
+        cert_data = _pad_bytes(cert_data)
+        return cert_data
+
+
+class CertificateChain:
+    """
+    A CertificateChain object used to parse the chain of certificates stored in a WAD that are used for the Wii's
+    content verification. The certificate chain is the format that the certificates are stored in as part of every WAD.
+
+    Attributes
+    ----------
+    ca_cert: Certificate
+        The CA certificate from the chain.
+    tmd_cert: Certificate
+        The CP (TMD) certificate from the chain.
+    ticket_cert: Certificate
+        The XS (Ticket) certificate from the chain.
+    """
+    def __init__(self):
+        self.ca_cert: Certificate = Certificate()
+        self.tmd_cert: Certificate = Certificate()
+        self.ticket_cert: Certificate = Certificate()
+
+    def load(self, cert_chain: bytes) -> None:
+        """
+        Loads certificate chain data into the CertificateChain object, allowing you to parse the individual
+        certificates stored in the chain.
+
+        Parameters
+        ----------
+        cert_chain: bytes
+            The data for the certificate chain to load.
+        """
+        with (io.BytesIO(cert_chain) as cert_chain_data):
+            # Read the two fields that denote different length sections of the certificate, so that we know how long
+            # this certificate is in total.
+            offset = 0x0
+            for _ in range(3):
+                cert_chain_data.seek(offset)
+                cert_type = CertificateType.from_bytes(cert_chain_data.read(0x4))
+                cert_chain_data.seek(offset + 0x80 + CertificateSignatureLength[cert_type.name].value)
+                key_type = CertificateKeyType.from_bytes(cert_chain_data.read(0x4))
+                cert_size = _align_value(0xC8 + CertificateSignatureLength[cert_type.name].value +
+                                               CertificateKeyLength[key_type.name].value)
+                cert_chain_data.seek(offset + 0x0)
+                cert = Certificate()
+                cert.load(cert_chain_data.read(cert_size))
+                if cert.issuer == "Root":
+                    self.ca_cert = cert
+                elif cert.issuer.find("Root-CA") != -1:
+                    if cert.child_name.find("CP") != -1:
+                        self.tmd_cert = cert
+                    elif cert.child_name.find("XS") != -1:
+                        self.ticket_cert = cert
+                    else:
+                        raise ValueError("Unknown certificate in chain!")
+                else:
+                    raise ValueError("Unknown certificate in chain!")
+                offset += cert_size
+
+    def dump(self) -> bytes:
+        """
+        Dumps the full certificate chain back into bytes. This chain will always be formatted with the CA cert first,
+        followed by the CP (TMD) cert, then finally the XS (Ticket) cert.
+
+        Returns
+        -------
+        bytes
+            The full certificate chain as bytes.
+        """
+        cert_chain_data = b''
+        cert_chain_data += self.ca_cert.dump()
+        cert_chain_data += self.tmd_cert.dump()
+        cert_chain_data += self.ticket_cert.dump()
+        return cert_chain_data
+
+
+def verify_ca_cert(ca_cert: Certificate) -> bool:
+    """
+    Verify a Wii CA certificate using the root public key. The retail or development root key will be automatically
+    selected based off of the name of the CA certificate provided.
+
+    Parameters
+    ----------
+    ca_cert: Certificate
+        The CA certificate to verify.
+
+    Returns
+    -------
+    bool
+        Whether the certificate is valid or not.
+    """
+    if ca_cert.issuer != "Root" or ca_cert.child_name.find("CA") == -1:
+        raise ValueError("The provided certificate is not a CA certificate!")
+    if ca_cert.child_name == "CA00000001":
+        root_key_modulus = \
+            (b'\xf8$lX\xba\xe7P\x03\x01\xfb\xb7\xc2\xeb\xe0\x01\x05q\xda\x92#x\xf0QN\xc0\x03\x1d\xd0\xd2\x1e\xd3\xd0~'
+             b'\xfc\x85 i\xb5\xde\x9b\xb9Q\xa8\xbc\x90\xa2D\x92m7\x92\x95\xae\x946\xaa\xa6\xa3\x02Q\x0c{\x1d\xed\xd5'
+             b'\xfb \x86\x9d\x7f0\x16\xf6\xbee\xd3\x83\xa1m\xb32\x1b\x955\x18\x90\xb1p\x02\x93~\xe1\x93\xf5~\x99\xa2GN'
+             b'\x9d8$\xc7\xae\xe3\x85A\xf5g\xe7Q\x8cz\x0e8\xe7\xeb\xafA\x19\x1b\xcf\xf1{B\xa6\xb4\xed\xe6\xce\x8d\xe71'
+             b'\x8f\x7fR\x04\xb3\x99\x0e"gE\xaf\xd4\x85\xb2D\x93\x00\x8b\x08\xc7\xf6\xb7\xe5k\x02\xb3\xe8\xfe\x0c\x9d'
+             b'\x85\x9c\xb8\xb6\x82#\xb8\xab\'\xee_e8\x07\x8b-\xb9\x1e*\x15>\x85\x81\x80r\xa2;m\xd92\x81\x05Oo\xb0\xf6'
+             b'\xf5\xad(>\xca\x0bz\xf3TU\xe0=\xa7\xb6\x83&\xf3\xec\x83J\xf3\x14\x04\x8a\xc6\xdf \xd2\x85\x08g<\xabb\xa2'
+             b'\xc7\xbc\x13\x1aS>\x0bf\x80k\x1c0fK7#1\xbd\xc4\xb0\xca\xd8\xd1\x1e\xe7\xbb\xd9(UH\xaa\xec\x1ff\xe8!\xb3'
+             b'\xc8\xa0Gi\x00\xc5\xe6\x88\xe8\x0c\xce<a\xd6\x9c\xbb\xa17\xc6`Ozr\xdd\x8c{>=Q)\r\xaajY{\x08\x1f\x9d63'
+             b'\xa3Fz5a\t\xac\xa7\xdd}./\xb2\xc1\xae\xb8\xe2\x0fH\x92\xd8\xb9\xf8\xb4oN<\x11\xf4\xf4}\x8bu}\xfe\xfe\xa3'
+             b'\x89\x9c3Y\\^\xfd\xeb\xcb\xab\xe8A>:\x9a\x80<i5n\xb2\xb2\xad\\\xc4\xc8XE^\xf5\xf7\xb3\x06D\xb4|d\x06\x8c'
+             b'\xdf\x80\x9fv\x02Z-\xb4F\xe0=|\xf6/4\xe7\x02E{\x02\xa4\xcf]\x9d\xd5<\xa5:|\xa6)x\x8cg\xca\x08\xbf\xec'
+             b'\xcaC\xa9W\xad\x16\xc9N\x1c\xd8u\xca\x10}\xce~\x01\x18\xf0\xdfk\xfe\xe5\x1d\xdb\xd9\x91\xc2n`\xcdHX\xaa'
+             b'Y,\x82\x00u\xf2\x9fRl\x91|o\xe5@>\xa7\xd4\xa5\x0c\xec;s\x84\xde\x88n\x82\xd2\xebMNB\xb5\xf2\xb1I\xa8\x1e'
+             b'\xa7\xceqD\xdc)\x94\xcf\xc4N\x1f\x91\xcb\xd4\x95')
+    elif ca_cert.child_name == "CA00000002":
+        root_key_modulus = \
+            (b'\x00\xd0\x1f\xe1\x00\xd45V\xb2KV\xda\xe9q\xb5\xa5\xd3\x84\xb90\x03\xbe\x1b\xbf(\xa20[\x06\x06EF}[\x02Q'
+             b'\xd2V\x1a\'O\x9e\x9f\x9c\xecdaP\xab=*\xe36hf\xac\xa4\xba\xe8\x1a\xe3\xd7\x9a\xa6\xb0J\x8b\xcb\xa7\xe6'
+             b'\xfbd\x89E\xeb\xdf\xdb\x85\xba\t\x1f\xd7\xd1\x14\xb5\xa3\xa7\x80\xe3\xa2.n\xcd\x87\xb5\xa4\xc6\xf9\x10'
+             b'\xe4\x03"\x08\x81K\x0c\xee\xa1\xa1}\xf79i_a~\xf65(\xdb\x94\x967\xa0V\x03\x7f{2A8\x95\xc0\xa8\xf1\x98.'
+             b'\x15e\xe3\x8e\xed\xc2.Y\x0e\xe2g{\x86\t\xf4\x8c.0?\xbc@\\\xac\x18\x04/\x82 \x84\xe4\x93h\x03\xda\x7fA4'
+             b'\x92HV+\x8e\xe1/x\xf8\x03$c0\xbc{\xe7\xeerJ\xf4X\xa4r\xe7\xabF\xa1\xa7\xc1\x0c/\x18\xfa\x07\xc3\xdd\xd8'
+             b'\x98\x06\xa1\x1c\x9c\xc10\xb2G\xa3<\x8dG\xdeg\xf2\x9eUw\xb1\x1cCI=[\xbav4\xa7\xe4\xe7\x151\xb7\xdfY\x81'
+             b'\xfe$\xa1\x14UL\xbd\x8f\x00\\\xe1\xdb5\x08\\\xcf\xc7x\x06\xb6\xde%@h\xa2l\xb5I-E\x80C\x8f\xe1\xe5\xa9'
+             b'\xedu\xc5\xedE\x1d\xcex\x949\xcc\xc3\xba(\xa21*\x1b\x87\x19\xef\x0fs\xb7\x13\x95\x0c\x02Y\x1atb\xa6\x07'
+             b'\xf3|\n\xa7\xa1\x8f\xa9C\xa3mu*_A\x92\xf0\x13a\x00\xaa\x9c\xb4\x1b\xbe\x14\xbe\xb1\xf9\xfci/\xdf\xa0\x94'
+             b'F\xdeZ\x9d\xde,\xa5\xf6\x8c\x1c\x0c!B\x92\x87\xcb-\xaa\xa3\xd2cu/s\xe0\x9f\xafDy\xd2\x81t)\xf6\x98\x00'
+             b'\xaf\xdekY-\xc1\x98\x82\xbd\xf5\x81\xcc\xab\xf2\xcb\x91\x02\x9e\xf3\\L\xfd\xbb\xffI\xc1\xfa\x1b/\xe3\x1d'
+             b'\xe7\xa5`\xec\xb4~\xbc\xfe2B[\x95o\x81\xb6\x99\x17H~;x\x91Q\xdb.x\xb1\xfd.\xbe~bk>\xa1e\xb4\xfb\x00\xcc'
+             b'\xb7Q\xafPs)\xc4\xa3\x93\x9e\xa6\xdd\x9cP\xa0\xe78k\x01EykA\xafa\xf7\x85U\x94O;\xc2-\xc3\xbd\r\x00\xf8y'
+             b'\x8aB\xb1\xaa\xa0\x83 e\x9a\xc79Z\xb4\xf3)')
+    else:
+        raise ValueError("The provided CA certificate is not valid!")
+    root_key_exponent = 0x00010001
+    cert_hash = SHA1.new(ca_cert.dump()[576:])
+    public_key = RSA.construct((int.from_bytes(root_key_modulus), root_key_exponent))
+    try:
+        pkcs1_15.new(public_key).verify(cert_hash, ca_cert.signature)
+        return True
+    except ValueError:
+        return False
+
+
+def verify_cert_sig(ca_cert: Certificate, target_cert: Certificate) -> bool:
+    """
+    Verify a TMD or Ticket certificate using a CA certificate.
+
+    Parameters
+    ----------
+    ca_cert: Certificate
+        The CA certificate to use for verification.
+    target_cert: Certificate
+        The target certificate to verify.
+
+    Returns
+    -------
+    bool
+        Whether the certificate's signature is valid or not.
+    """
+    if ca_cert.issuer != "Root" or ca_cert.child_name.find("CA") == -1:
+        raise ValueError("The provided certificate is not a CA certificate!")
+    # The issuer of the TMD/Ticket certs is Root-CA0000000X, so prepend "Root-" to the CA cert child name. If these
+    # don't match, then there's probably a mismatch between retail and development certs.
+    if f"Root-{ca_cert.child_name}" != target_cert.issuer:
+        raise ValueError("The certificate you are trying to verify does not match the provided CA certificate!")
+    cert_hash = SHA1.new(target_cert.dump()[320:])
+    public_key = RSA.construct((ca_cert.pub_key_modulus, ca_cert.pub_key_exponent))
+    try:
+        pkcs1_15.new(public_key).verify(cert_hash, target_cert.signature)
+        return True
+    except ValueError:
+        return False
+
+
+def verify_tmd_sig(tmd_cert: Certificate, tmd: TMD) -> bool:
+    """
+    Verify the signature of a TMD file using a TMD certificate.
+
+    Parameters
+    ----------
+    tmd_cert: Certificate
+        The TMD certificate to use for verification.
+    tmd: TMD
+        The TMD to verify.
+
+    Returns
+    -------
+    bool
+        Whether the TMD's signature is valid or not.
+    """
+    if tmd_cert.issuer.find("Root-CA") == -1 or tmd_cert.child_name.find("CP") == -1:
+        raise ValueError("The provided TMD certificate is not valid!")
+    if f"{tmd_cert.issuer}-{tmd_cert.child_name}" != tmd.signature_issuer:
+        raise ValueError("The signature you are trying to verify was not created with the provided TMD certificate!")
+    tmd_hash = SHA1.new(tmd.dump()[320:])
+    public_key = RSA.construct((tmd_cert.pub_key_modulus, tmd_cert.pub_key_exponent))
+    try:
+        pkcs1_15.new(public_key).verify(tmd_hash, tmd.signature)
+        return True
+    except ValueError:
+        return False
+
+
+def verify_ticket_sig(ticket_cert: Certificate, ticket: Ticket) -> bool:
+    """
+    Verify the signature of a Ticket file using a Ticket certificate.
+
+    Parameters
+    ----------
+    ticket_cert: Certificate
+        The Ticket certificate to use for verification.
+    ticket: Ticket
+        The Ticket to verify.
+
+    Returns
+    -------
+    bool
+        Whether the Ticket's signature is valid or not.
+    """
+    if ticket_cert.issuer.find("Root-CA") == -1 or ticket_cert.child_name.find("XS") == -1:
+        raise ValueError("The provided Ticket certificate is not valid!")
+    if f"{ticket_cert.issuer}-{ticket_cert.child_name}" != ticket.signature_issuer:
+        raise ValueError("The signature you are trying to verify was not created with the provided Ticket certificate!")
+    ticket_hash = SHA1.new(ticket.dump()[320:])
+    public_key = RSA.construct((ticket_cert.pub_key_modulus, ticket_cert.pub_key_exponent))
+    try:
+        pkcs1_15.new(public_key).verify(ticket_hash, ticket.signature)
+        return True
+    except ValueError:
+        return False

src/libWiiPy/title/crypto.py

@@ -1,8 +1,8 @@
 # "title/crypto.py" from libWiiPy by NinjaCheetah & Contributors
 # https://github.com/NinjaCheetah/libWiiPy
 
-import struct
 import binascii
+import struct
 from .commonkeys import get_common_key
 from Crypto.Cipher import AES as _AES
 

src/libWiiPy/title/nus.py

@@ -4,9 +4,9 @@
 # See https://wiibrew.org/wiki/NUS for details about the NUS
 
 import requests
-import hashlib
+#import hashlib
 from typing import List
-from urllib.parse import urlparse as _urlparse
+#from urllib.parse import urlparse as _urlparse
 from .title import Title
 from .tmd import TMD
 from .ticket import Ticket
@@ -40,10 +40,10 @@ def download_title(title_id: str, title_version: int = None, wiiu_endpoint: bool
     """
     # First, create the new title.
     title = Title()
-    # Download and load the TMD, Ticket, and certs.
+    # Download and load the certificate chain, TMD, and Ticket.
+    title.load_cert_chain(download_cert_chain(wiiu_endpoint, endpoint_override))
     title.load_tmd(download_tmd(title_id, title_version, wiiu_endpoint, endpoint_override))
     title.load_ticket(download_ticket(title_id, wiiu_endpoint, endpoint_override))
-    title.wad.set_cert_data(download_cert(wiiu_endpoint, endpoint_override))
     # Download all contents
     title.load_content_records()
     title.content.content_list = download_contents(title_id, title.tmd, wiiu_endpoint, endpoint_override)
@@ -88,7 +88,14 @@ def download_tmd(title_id: str, title_version: int = None, wiiu_endpoint: bool =
     if title_version is not None:
         tmd_url += "." + str(title_version)
     # Make the request.
-    tmd_request = requests.get(url=tmd_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True)
+    try:
+        tmd_request = requests.get(url=tmd_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True)
+    except requests.exceptions.ConnectionError:
+        if endpoint_override:
+            raise ValueError("A connection could not be made to the NUS endpoint. Please make sure that your endpoint "
+                             "override is valid.")
+        else:
+            raise Exception("A connection could not be made to the NUS endpoint. The NUS may be unavailable.")
     # Handle a 404 if the TID/version doesn't exist.
     if tmd_request.status_code != 200:
         raise ValueError("The requested Title ID or TMD version does not exist. Please check the Title ID and Title"
@@ -133,7 +140,14 @@ def download_ticket(title_id: str, wiiu_endpoint: bool = False, endpoint_overrid
             endpoint_url = _nus_endpoint[0]
     ticket_url = endpoint_url + title_id + "/cetk"
     # Make the request.
-    ticket_request = requests.get(url=ticket_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True)
+    try:
+        ticket_request = requests.get(url=ticket_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True)
+    except requests.exceptions.ConnectionError:
+        if endpoint_override:
+            raise ValueError("A connection could not be made to the NUS endpoint. Please make sure that your endpoint "
+                             "override is valid.")
+        else:
+            raise Exception("A connection could not be made to the NUS endpoint. The NUS may be unavailable.")
     if ticket_request.status_code != 200:
         raise ValueError("The requested Title ID does not exist, or refers to a non-free title. Tickets can only"
                          " be downloaded for titles that are free on the NUS.")
@@ -146,9 +160,9 @@ def download_ticket(title_id: str, wiiu_endpoint: bool = False, endpoint_overrid
     return ticket
 
 
-def download_cert(wiiu_endpoint: bool = False, endpoint_override: str = None) -> bytes:
+def download_cert_chain(wiiu_endpoint: bool = False, endpoint_override: str = None) -> bytes:
     """
-    Downloads the signing certificate used by all WADs. This uses System Menu 4.3U as the source.
+    Downloads the signing certificate chain used by all WADs. This uses System Menu 4.3U as the source.
 
     Parameters
     ----------
@@ -163,7 +177,7 @@ def download_cert(wiiu_endpoint: bool = False, endpoint_override: str = None) ->
     bytes
         The cert file.
     """
-    # Download the TMD and cetk for the System Menu 4.3U.
+    # Download the TMD and cetk for System Menu 4.3U (v513).
     if endpoint_override is not None:
         endpoint_url = _validate_endpoint(endpoint_override)
     else:
@@ -173,20 +187,28 @@ def download_cert(wiiu_endpoint: bool = False, endpoint_override: str = None) ->
             endpoint_url = _nus_endpoint[0]
     tmd_url = endpoint_url + "0000000100000002/tmd.513"
     cetk_url = endpoint_url + "0000000100000002/cetk"
-    tmd = requests.get(url=tmd_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True).content
+    try:
-    cetk = requests.get(url=cetk_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True).content
+        tmd = requests.get(url=tmd_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True).content
-    # Assemble the certificate.
+        cetk = requests.get(url=cetk_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True).content
-    cert = b''
+    except requests.exceptions.ConnectionError:
+        if endpoint_override:
+            raise ValueError("A connection could not be made to the NUS endpoint. Please make sure that your endpoint "
+                             "override is valid.")
+        else:
+            raise Exception("A connection could not be made to the NUS endpoint. The NUS may be unavailable.")
+    # Assemble the certificate chain.
+    cert_chain = b''
     # Certificate Authority data.
-    cert += cetk[0x2A4 + 768:]
+    cert_chain += cetk[0x2A4 + 768:]
-    # Certificate Policy data.
+    # Certificate Policy (TMD certificate) data.
-    cert += tmd[0x328:0x328 + 768]
+    cert_chain += tmd[0x328:0x328 + 768]
-    # XS data.
+    # XS (Ticket certificate) data.
-    cert += cetk[0x2A4:0x2A4 + 768]
+    cert_chain += cetk[0x2A4:0x2A4 + 768]
-    # Since the cert is always the same, check the hash to make sure nothing went wildly wrong.
+    # Since the cert chain is always the same, check the hash to make sure nothing went wildly wrong.
-    if hashlib.sha1(cert).hexdigest() != "ace0f15d2a851c383fe4657afc3840d6ffe30ad0":
+    # This is currently disabled because of the possibility that one may be downloading non-retail certs (gasp!).
-        raise Exception("An unknown error has occurred downloading and creating the certificate.")
+    #if hashlib.sha1(cert_chain).hexdigest() != "ace0f15d2a851c383fe4657afc3840d6ffe30ad0":
-    return cert
+    #    raise Exception("An unknown error has occurred downloading and creating the certificate.")
+    return cert_chain
 
 
 def download_content(title_id: str, content_id: int, wiiu_endpoint: bool = False,
@@ -224,7 +246,14 @@ def download_content(title_id: str, content_id: int, wiiu_endpoint: bool = False
             endpoint_url = _nus_endpoint[0]
     content_url = endpoint_url + title_id + "/000000" + content_id_hex
     # Make the request.
-    content_request = requests.get(url=content_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True)
+    try:
+        content_request = requests.get(url=content_url, headers={'User-Agent': 'wii libnup/1.0'}, stream=True)
+    except requests.exceptions.ConnectionError:
+        if endpoint_override:
+            raise ValueError("A connection could not be made to the NUS endpoint. Please make sure that your endpoint "
+                             "override is valid.")
+        else:
+            raise Exception("A connection could not be made to the NUS endpoint. The NUS may be unavailable.")
     if content_request.status_code != 200:
         raise ValueError("The requested Title ID does not exist, or an invalid Content ID is present in the"
                          " content records provided.\n Failed while downloading Content ID: 000000" +
@@ -286,9 +315,10 @@ def _validate_endpoint(endpoint: str) -> str:
         The validated NUS endpoint with the proper path.
     """
     # Find the root of the URL and then assemble the correct URL based on that.
-    new_url = _urlparse(endpoint)
+    # TODO: Rewrite in a way that makes more sense and un-stub
-    if new_url.netloc == "":
+    #new_url = _urlparse(endpoint)
-        endpoint_url = "http://" + new_url.path + "/ccs/download/"
+    #if new_url.netloc == "":
-    else:
+    #    endpoint_url = "http://" + new_url.path + "/ccs/download/"
-        endpoint_url = "http://" + new_url.netloc + "/ccs/download/"
+    #else:
-    return endpoint_url
+    #    endpoint_url = "http://" + new_url.netloc + "/ccs/download/"
+    return endpoint

src/libWiiPy/title/ticket.py

@@ -107,7 +107,7 @@ class Ticket:
             self.signature = ticket_data.read(256)
             # Signature issuer.
             ticket_data.seek(0x140)
-            self.signature_issuer = str(ticket_data.read(64).decode())
+            self.signature_issuer = str(ticket_data.read(64).replace(b'\x00', b'').decode())
             # ECDH data.
             ticket_data.seek(0x180)
             self.ecdh_data = ticket_data.read(60)
@@ -128,7 +128,7 @@ class Ticket:
             self.console_id = int.from_bytes(ticket_data.read(4))
             # Title ID.
             ticket_data.seek(0x1DC)
-            self.title_id = binascii.hexlify(ticket_data.read(8))
+            self.title_id = ticket_data.read(8)
             # Unknown data 1.
             ticket_data.seek(0x1E4)
             self.unknown1 = ticket_data.read(2)
@@ -160,7 +160,8 @@ class Ticket:
                 limit_value = int.from_bytes(ticket_data.read(4))
                 self.title_limits_list.append(_TitleLimit(limit_type, limit_value))
         # Check certs to see if this is a retail or dev ticket. Treats unknown certs as being retail for now.
-        if self.signature_issuer.find("Root-CA00000002-XS00000006") != -1:
+        if (self.signature_issuer.find("Root-CA00000002-XS00000006") != -1 or
+                self.signature_issuer.find("Root-CA00000002-XS00000004") != -1):
             self.is_dev = True
         else:
             self.is_dev = False
@@ -182,7 +183,10 @@ class Ticket:
         # Padding to 64 bytes.
         ticket_data += b'\x00' * 60
         # Signature issuer.
-        ticket_data += str.encode(self.signature_issuer)
+        signature_issuer = self.signature_issuer.encode()
+        while len(signature_issuer) < 0x40:
+            signature_issuer += b'\x00'
+        ticket_data += signature_issuer
         # ECDH data.
         ticket_data += self.ecdh_data
         # Ticket version.
@@ -198,7 +202,7 @@ class Ticket:
         # Console ID.
         ticket_data += int.to_bytes(self.console_id, 4)
         # Title ID.
-        ticket_data += binascii.unhexlify(self.title_id)
+        ticket_data += self.title_id
         # Unknown data 1.
         ticket_data += self.unknown1
         # Title version.
@@ -314,6 +318,8 @@ class Ticket:
                 return "Korean"
             case 2:
                 return "vWii"
+            case _:
+                return "Unknown"
 
     def get_title_key(self) -> bytes:
         """
@@ -339,7 +345,7 @@ class Ticket:
         """
         if len(title_id) != 16:
             raise ValueError("Invalid Title ID! Title IDs must be 8 bytes long.")
-        self.title_id = title_id.encode()
+        self.title_id = binascii.unhexlify(title_id.encode())
 
     def set_title_version(self, new_version: str | int) -> None:
         """

src/libWiiPy/title/title.py

@@ -4,10 +4,13 @@
 # See https://wiibrew.org/wiki/Title for details about how titles are formatted
 
 import math
-from .content import ContentRegion
+from .cert import (CertificateChain as _CertificateChain,
-from .ticket import Ticket
+                   verify_ca_cert as _verify_ca_cert, verify_cert_sig as _verify_cert_sig,
-from .tmd import TMD
+                   verify_tmd_sig as _verify_tmd_sig, verify_ticket_sig as _verify_ticket_sig)
-from .wad import WAD
+from .content import ContentRegion as _ContentRegion
+from .ticket import Ticket as _Ticket
+from .tmd import TMD as _TMD
+from .wad import WAD as _WAD
 from .crypto import encrypt_title_key
 
 
@@ -19,20 +22,23 @@ class Title:
 
     Attributes
     ----------
-    wad : WAD
+    wad: WAD
         A WAD object of a WAD containing the title's data.
-    tmd : TMD
+    cert_chain: CertificateChain
+        The chain of certificates used to verify the contents of a title.
+    tmd: TMD
         A TMD object of the title's TMD.
-    ticket : Ticket
+    ticket: Ticket
         A Ticket object of the title's Ticket.
     content: ContentRegion
         A ContentRegion object containing the title's contents.
     """
     def __init__(self):
-        self.wad: WAD = WAD()
+        self.wad: _WAD = _WAD()
-        self.tmd: TMD = TMD()
+        self.cert_chain: _CertificateChain = _CertificateChain()
-        self.ticket: Ticket = Ticket()
+        self.tmd: _TMD = _TMD()
-        self.content: ContentRegion = ContentRegion()
+        self.ticket: _Ticket = _Ticket()
+        self.content: _ContentRegion = _ContentRegion()
 
     def load_wad(self, wad: bytes) -> None:
         """
@@ -45,16 +51,19 @@ class Title:
             The data for the WAD you wish to load.
         """
         # Create a new WAD object based on the WAD data provided.
-        self.wad = WAD()
+        self.wad = _WAD()
         self.wad.load(wad)
+        # Load the certificate chain.
+        self.cert_chain = _CertificateChain()
+        self.cert_chain.load(self.wad.get_cert_data())
         # Load the TMD.
-        self.tmd = TMD()
+        self.tmd = _TMD()
         self.tmd.load(self.wad.get_tmd_data())
         # Load the ticket.
-        self.ticket = Ticket()
+        self.ticket = _Ticket()
         self.ticket.load(self.wad.get_ticket_data())
         # Load the content.
-        self.content = ContentRegion()
+        self.content = _ContentRegion()
         self.content.load(self.wad.get_content_data(), self.tmd.content_records)
         # Ensure that the Title IDs of the TMD and Ticket match before doing anything else. If they don't, throw an
         # error because clearly something strange has gone on with the WAD and editing it probably won't work.
@@ -75,6 +84,8 @@ class Title:
         # Set WAD type to ib if the title being packed is boot2.
         if self.tmd.title_id == "0000000100000001":
             self.wad.wad_type = "ib"
+        # Dump the certificate chain and set it in the WAD.
+        self.wad.set_cert_data(self.cert_chain.dump())
         # Dump the TMD and set it in the WAD.
         # This requires updating the content records and number of contents in the TMD first.
         self.tmd.content_records = self.content.content_records  # This may not be needed because it's a ref already
@@ -87,6 +98,19 @@ class Title:
         self.wad.set_content_data(content_data, content_size)
         return self.wad.dump()
 
+    def load_cert_chain(self, cert_chain: bytes) -> None:
+        """
+        Load an existing certificate chain into the title. Note that this will overwrite any existing certificate chain
+        data for this title.
+
+        Parameters
+        ----------
+        cert_chain: bytes
+            The data for the certificate chain to load.
+        """
+        self.cert_chain.load(cert_chain)
+
+
     def load_tmd(self, tmd: bytes) -> None:
         """
         Load existing TMD data into the title. Note that this will overwrite any existing TMD data for this title.
@@ -94,9 +118,8 @@ class Title:
         Parameters
         ----------
         tmd : bytes
-            The data for the WAD you wish to load.
+            The data for the TMD to load.
         """
-        # Load TMD.
         self.tmd.load(tmd)
 
     def load_ticket(self, ticket: bytes) -> None:
@@ -107,9 +130,8 @@ class Title:
         Parameters
         ----------
         ticket : bytes
-            The data for the WAD you wish to load.
+            The data for the Ticket to load.
         """
-        # Load Ticket.
         self.ticket.load(ticket)
 
     def load_content_records(self) -> None:
@@ -398,3 +420,34 @@ class Title:
             return True
         else:
             return False
+
+    def get_is_signed(self) -> bool:
+        """
+        Uses the certificate chain to verify whether the Title object contains a properly signed title or not. This
+        verifies both the TMD and Ticket, and if either one fails verification then the title is not considered valid.
+
+        This will validate the entire certificate chain. If any part of the chain doesn't match the other pieces, then
+        this method will raise an exception.
+
+        Returns
+        -------
+        bool
+            Whether the title is properly signed or not.
+
+        See Also
+        --------
+        libWiiPy.title.cert
+        """
+        # The entire chain needs to be verified, so start with the CA cert and work our way down. If anything fails
+        # along the way, future steps don't matter so exit the descending if's and return False.
+        try:
+            if _verify_ca_cert(self.cert_chain.ca_cert) is True:
+                if _verify_cert_sig(self.cert_chain.ca_cert, self.cert_chain.tmd_cert) is True:
+                    if _verify_tmd_sig(self.cert_chain.tmd_cert, self.tmd) is True:
+                        if _verify_cert_sig(self.cert_chain.ca_cert, self.cert_chain.ticket_cert) is True:
+                            if _verify_ticket_sig(self.cert_chain.ticket_cert, self.ticket) is True:
+                                return True
+        except ValueError:
+            raise ValueError("This title's certificate chain is not valid, or does not match the signature type of "
+                             "the TMD/Ticket.")
+        return False

src/libWiiPy/title/tmd.py

@@ -83,7 +83,7 @@ class TMD:
             self.signature = tmd_data.read(256)
             # Signing certificate issuer.
             tmd_data.seek(0x140)
-            self.signature_issuer = str(tmd_data.read(64).decode())
+            self.signature_issuer = str(tmd_data.read(64).replace(b'\x00', b'').decode())
             # TMD version, seems to usually be 0, but I've seen references to other numbers.
             tmd_data.seek(0x180)
             self.tmd_version = int.from_bytes(tmd_data.read(1))
@@ -175,7 +175,10 @@ class TMD:
         # Padding to 64 bytes.
         tmd_data += b'\x00' * 60
         # Signing certificate issuer.
-        tmd_data += str.encode(self.signature_issuer)
+        signature_issuer = self.signature_issuer.encode()
+        while len(signature_issuer) < 0x40:
+            signature_issuer += b'\x00'
+        tmd_data += signature_issuer
         # TMD version.
         tmd_data += int.to_bytes(self.tmd_version, 1)
         # Certificate Authority CRL version.