msi-example: add instructions and sample code

1 files changed, 38 insertions, 0 deletions

diff --git a/msi-example/README.md b/msi-example/README.md
new file mode 100644
index 0000000..4197de7
--- /dev/null
+++ b/msi-example/README.md
@@ -0,0 +1,38 @@
+## Example Standalone MSI
+
+The best way to include Wintun in your software is by including the MSMs in your final MSI,
+as described by [the main README](../README.md). However, if you're stuck with an installation
+system such as NSIS, which can not bundle MSM files, then you must build your own MSI, which
+NSIS can then invoke. ***Do not use an MSI from elsewhere. You must build it yourself and
+distribute only the MSI that you yourself build.*** Otherwise different projects will wind up
+uninstalling each other by accident and disturbing the MSM reference counting. The steps in
+this file should only be taken if you're not able to include an MSM into a MSI, something that
+is easily possible using WiX or most commercial installation solutions.
+
+This `msi-example` folder contains a WiX skeleton and a build script that handles all
+dependencies. use it as follows below.
+
+#### Steps:
+
+1. Generate a UUID using uuidgen.exe and replace `{{{FIXED 64BIT UUID}}}` in exampletun.wxs
+with that UUID. For the life time of your entire product, even across versions, do not change
+that UUID.
+
+2. Generate another UUID using uuidgen.exe and replace `{{{FIXED 32BIT UUID}}}` in
+exampletun.wxs with that UUID. For the life time of your entire product, even across versions,
+do not change that UUID.
+
+3. Go to [Wintun.net](https://www.wintun.net/) and look at what the latest version is (`0.6`,
+for example). Replace `{{{VERSION}}}` in build.bat with that version.
+
+4. Download the amd64 MSM from [Wintun.net](https://www.wintun.net/) and compute its SHA2-256
+sum in all lowercase hex digits using `CertUtil -hashfile "path/to/file" SHA256`, and replace
+`{{{64BIT HASH}}}` in build.bat with that value.
+
+5. Download the x86 MSM from [Wintun.net](https://www.wintun.net/) and compute its SHA2-256
+sum in all lowercase hex digits using `CertUtil -hashfile "path/to/file" SHA256`, and replace
+`{{{32BIT HASH}}}` in build.bat with that value.
+
+6. Run build.bat.
+
+7. Distribute dist\exampletun-*.msi for your own software only.