installation/index: remove signify instructions

signify and minisign are no longer cross-compatible, and minisign is
more cross-platform and will have some integrations into xbps, so it
makes more sense to use minisign from now on.

also update the instructions using the 20230628 images.

Author: classabbyamp

src/installation/index.md

@@ -63,23 +63,12 @@ This verifies that the image is not corrupt.
 Prior to using any image you're strongly encouraged to validate the signatures
 on the image to ensure they haven't been tampered with.
 
-Current images are signed using a signify key that is specific to the release.
+Current images are signed using a minisign key that is specific to the release.
 If you're on Void already, you can obtain the keys from the `void-release-keys`
 package, which will be downloaded using your existing XBPS trust relationship
 with your mirror and package signatures. You will also need a copy of
-[signify(1)](https://man.voidlinux.org/signify.1) or
-[minisign(1)](https://man.voidlinux.org/minisign.1); on Void, these are provided
-by the `outils` or `minisign` packages, respectively.
-
-To obtain `signify` when using a Linux distribution or operating system other
-than Void Linux:
-
-- Install the `signify` package in Arch Linux and Arch-based distros.
-- Install the `signify-openbsd` package in Debian and Debian-based distros.
-- Install the package listed
-   [here](https://repology.org/project/signify-openbsd/versions) for your
-   distribution.
-- Install `signify-osx` with homebrew in macOS.
+[minisign(1)](https://man.voidlinux.org/minisign.1); on Void, this is provided
+by the `minisign` package.
 
 The `minisign` executable is usually provided by a package of the same name, and
 can also be installed on Windows, even without WSL or MinGW.
@@ -92,44 +81,36 @@ Once you've obtained the key, you can verify your image with the `sha256sum.sig`
 and `sha256sum.txt` files. First, you need to verify the authenticity of the
 `sha256sum.txt` file.
 
-The following examples demonstrate the verification of the `sha256sum.txt` file
-for the 20210930 images. Firstly, with `signify`:
+The following example demonstrates the verification of the `sha256sum.txt` file
+for the 20230628 images with `minisign`:
 
 ```
-$ signify -V -p /etc/signify/void-release-20210930.pub -x sha256sum.sig -m sha256sum.txt
-Signature Verified
-```
-
-And secondly, with `minisign`:
-
-```
-$ minisign -V -p /etc/signify/void-release-20210930.pub -x sha256sum.sig -m sha256sum.txt
+$ minisign -V -p /usr/share/void-release-keys/void-release-20230628.pub -x sha256sum.sig -m sha256sum.txt
 Signature and comment signature verified
-Trusted comment: timestamp:1634597366	file:sha256sum.txt
+Trusted comment: This key is only valid for images with date 20230628.
 ```
 
 Finally, you need to verify that the checksum for your image matches the one in
 the `sha256sum.txt` file. This can be done with the
-[sha256(1)](https://man.voidlinux.org/md5.1) utility, again from the `outils`
-package, as demonstrated below for the 20210930 `x86_64` image:
+[sha256(1)](https://man.voidlinux.org/md5.1) utility from the `outils` package,
+as demonstrated below for the 20230628 `x86_64` base image:
 
 ```
-$ sha256 -C sha256sum.txt void-live-x86_64-20210930.iso
-(SHA256) void-live-x86_64-20210930.iso: OK
+$ sha256 -C sha256sum.txt void-live-x86_64-20230628-base.iso 
+(SHA256) void-live-x86_64-20230628-base.iso: OK
 ```
 
-Alternatively, if the `sha256` utility isn't available to you, you can compute
-the SHA256 hash of the file, e.g. using
-[sha256sum(1)](https://man.voidlinux.org/sha256sum.1), and compare it to the
-value contained in `sha256sum.txt`:
+Alternatively, if the `sha256` utility isn't available to you, you can use
+[sha256sum(1)](https://man.voidlinux.org/sha256sum.1):
 
 ```
-$ sha256sum void-live-x86_64-20210930.iso
-45b75651eb369484e1e63ba803a34e9fe8a13b24695d0bffaf4dfaac44783294  void-live-x86_64-20210930.iso
-$ grep void-live-x86_64-20210930.iso sha256sum.txt
-SHA256 (void-live-x86_64-20210930.iso) = 45b75651eb369484e1e63ba803a34e9fe8a13b24695d0bffaf4dfaac44783294
+$ sha256sum -c sha256sum.txt --ignore-missing
+void-live-x86_64-20230628-base.iso: OK
 ```
 
+If neither program is available to you, you can compute the SHA256 hash of the
+file and compare it to the value contained in `sha256sum.txt`.
+
 If the verification process does not produce the expected "OK" status, do not
 use it! Please alert the Void Linux team of where you got the image and how you
 verified it, and we will follow up on it.