Hacking Question Can someone explain what each sig patch does?

[AdmiralSpeedy]

I'm making this post purely out of curiosity, because I see the question asked constantly and nobody ever gives a clear answer.

I'm trying to find an actually explanation of what each patch in the set of Atmosphere sig patches does. From this conversation and this website I understand the following:

• FS - Filesystem service patches that allow for the installation of unsigned/modified NSPs.
• ES - ETicket service patches that allow for the installation of fake tickets (for piracy using signed NSPs).
• ACID - Something to do with a file header that allows the installation of XCI files.
• Loader - I have absolutely no clue because whenever someone asks what these do, they are just told that they are required because AMS implements a replacement Loader module. The only thing I can find on these patches are that they need to be updated with every new version of AMS and that they have something to do with ES patches.

For the most part I understand the FS and ES patches and I have a vague idea of the purpose of ACID patches (however, I'm pretty sure I was able to install an XCI without them when I was testing this, but I could be wrong) but I have absolutely no clue what the Loader patches do, especially because I saw a comment saying they are REQUIRED for ES sig patches to work, which is not true because I currently have only the ES patches installed (no FS/ACID or Loader, I only took the ES patches from the archive because I do not install unsigned NSPs or XCIs anymore) and they work completely fine without the Loader patches installed at all.

Another thing that has me confused is this post, and this comment which links to this other comment that claims that you don't even need ES patches to installed signed NSPs if they have real tickets in them. Wouldn't the original ticket require the original console and/or account that downloaded the game to run without any sig patches? I could understand this for backups of games you own, since you would be playing them on the same console and account you bought them on, but both of those comments say it also applies to pirating games but I have never once seen a signed NSPs work without ES patches, so does this mean they all have fake tickets?

I'm only asking because I'm a very technical person (software developer) that likes to tinker with this stuff, and I just want to know exactly what these things do because it seems like the Switch Homebrew scene really loves vague documentation.

 

[DocKlokMan]

I'm making this post purely out of curiosity, because I see the question asked constantly and nobody ever gives a clear answer.

I'm trying to find an actually explanation of what each patch in the set of Atmosphere sig patches does. From this conversation and this website I understand the following:

• FS - Filesystem service patches that allow for the installation of unsigned/modified NSPs.
• ES - ETicket service patches that allow for the installation of fake tickets (for piracy using signed NSPs).
• ACID - Something to do with a file header that allows the installation of XCI files.
• Loader - I have absolutely no clue because whenever someone asks what these do, they are just told that they are required because AMS implements a replacement Loader module. The only thing I can find on these patches are that they need to be updated with every new version of AMS and that they have something to do with ES patches.

For the most part I understand the FS and ES patches and I have a vague idea of the purpose of ACID patches (however, I'm pretty sure I was able to install an XCI without them when I was testing this, but I could be wrong) but I have absolutely no clue what the Loader patches do, especially because I saw a comment saying they are REQUIRED for ES sig patches to work, which is not true because I currently have only the ES patches installed (no FS/ACID or Loader, I only took the ES patches from the archive because I do not install unsigned NSPs or XCIs anymore) and they work completely fine without the Loader patches installed at all.

Another thing that has me confused is this post, and this comment which links to this other comment that claims that you don't even need ES patches to installed signed NSPs if they have real tickets in them. Wouldn't the original ticket require the original console and/or account that downloaded the game to run without any sig patches? I could understand this for backups of games you own, since you would be playing them on the same console and account you bought them on, but both of those comments say it also applies to pirating games but I have never once seen a signed NSPs work without ES patches, so does this mean they all have fake tickets?

I'm only asking because I'm a very technical person (software developer) that likes to tinker with this stuff, and I just want to know exactly what these things do because it seems like the Switch Homebrew scene really loves vague documentation.

First, FS patches are basically a kind of ACID patch but it's called FS because these patches only affect the ACID patching for installed NCAs while ACID is typically referring to XCIs but technically they're both ACID patches just with two different kind of crypto.

When Nintendo released system update 10.0.0 they added ACID (FS) checking for NCA's into their loader module. Since Atmosphere strives to fully replicate all of Nintendo's functionality, Atmosphere started doing this in their version of loader in version 0.11.1. Loader doesn't have anything to do with ES, which are ticket patches like you've read, it has to do with ACID/FS patches. This would impact installing XCI's or homebrew forwarder NSPs like Tinfoil. That's why you don't need Loader patches since you're only installing properly signed NSPs and just using fake tickets.

As for your uncertainty about whether ACID patches are even needed for installing XCI's it's because there's two ways to install XCIs. When the XCIs are converted to NSP (either prior or on the fly during install) you can either install them as is with standard crypto in tact (this will cause them to fail ACID check and need ACID patches) or you can convert them to the crypto system eShop games use (which would cause them to fail FS check and need FS patches). So depending on what app you were using and what patches you had it's possible you may have installed an XCI without ACID patches, but you would have needed one or the other.

As for not needing ES patches for real tickets, game updates all have a "common" ticket and are completely legit and can be installed without ES patches. But saying it can be used for piracy is completely false. Piracy implies fake tickets and fake tickets need ES patching, end of story. Doesn't matter what anyone else says.

In relation to the posts you link we're technically not supposed to support piracy here, so the "legal backups" referenced by hellogbatemp is sarcastic code for pirated games. Brawl345 is clarifying that those with actual legit backups don't need ES patches which is a sly way of pulling hellogbatemp's cover away. Rajkosto's post is from when NSP piracy just started to become a thing and the "safer" way to pirate was with XCIs which didn't install fake tickets. This was him saying XCIs are superior to NSPs which a lot of people still feel the same way. Cyan's explanation on loader changes is just wrong, it doesn't do anything with ES, which is probably where the source of your confusion (and many's belief you need the loader patch even if you're only using signed NSPs) likely comes from.