ENT-13792: Made Windows MSI assembly fully reproducible

build-scripts/package-msi

@@ -13,6 +13,36 @@
 # MSI packaging uses wixl (GNOME msitools), which builds Windows MSIs natively
 # on Linux - no Windows and no Wine.
 
+# Derive a deterministic GUID from a label (ENT-13792)
+deterministic_guid() {
+    printf '{%s}\n' "$(uuidgen --sha1 \
+        --namespace B883FBCC-6F05-4AFA-98FA-CAF09BF464EA \
+        --name "$1" | tr '[:lower:]' '[:upper:]')"
+}
+
+# Make the Summary Information reproducible: wixl writes a random package code
+# (property 9) and the wall-clock build time (12/13 = Created/Last saved).
+# Rewrite them to a version-derived package code and SOURCE_DATE_EPOCH.
+# (ENT-13792)
+normalize_msi_summary() {
+    msi="$1"
+    revision="$2"
+    if [ -z "$SOURCE_DATE_EPOCH" ]; then
+        log_debug "SOURCE_DATE_EPOCH unset; skipping MSI summary normalization"
+        return 0
+    fi
+    pkgcode=$(deterministic_guid "package:$revision")
+    datestr=$(TZ=UTC date -u -d "@$SOURCE_DATE_EPOCH" +"%Y/%m/%d %H:%M:%S")
+    msiinfo export "$msi" _SummaryInformation | tr -d '\r' |
+        awk -v u="$pkgcode" -v d="$datestr" -F '\t' 'BEGIN { OFS = "\t" }
+            $1 == "9"  { $2 = u }
+            $1 == "12" { $2 = d }
+            $1 == "13" { $2 = d }
+            { print }' | sed 's/$/\r/' >_summary.idt
+    msibuild "$msi" -i _summary.idt
+    rm -f _summary.idt
+}
+
 # Determine build directory name based on Jenkins job or version/arch
 log_debug "Determining build directory name (JOB_NAME=$JOB_NAME, VERSION=$VERSION, ARCH=$ARCH)"
 if [ -z "$JOB_NAME" ]; then
@@ -85,6 +115,13 @@ pre() {
     if [ "$ARCH" = "x86" ]; then
         sed -i '/lib\(crypto\|ssl\)/s/[_-]x64//g' "$P"/cfengine-nova.wxs
     fi
+
+    # Reproducible builds (ENT-13792): pin every packaged file's mtime to
+    # SOURCE_DATE_EPOCH so the CAB stores a fixed timestamp per file instead
+    # of the time each file was created.
+    if [ -n "$SOURCE_DATE_EPOCH" ]; then
+        find "$P" -exec touch -h -d "@$SOURCE_DATE_EPOCH" {} +
+    fi
 }
 
 # wixl_build() - Build the MSI from the WiX source using wixl (msitools).
@@ -108,7 +145,13 @@ wixl_build() {
     log_debug "Running wixl with REVISION=$REVISION, ARCH=$ARCH"
     wixl -a "$wixl_arch" \
         -D CfSourceDir=. -D CfVersion="$REVISION" -D CfArch="$ARCH" \
+        -D CfProductCode="$(deterministic_guid "product:$REVISION")" \
         -o cfengine-nova.msi cfengine-nova.wxs
+
+    # wixl still bakes a random package code and the wall-clock build time into
+    # the Summary Information; rewrite them for a byte-reproducible MSI.
+    # (ENT-13792)
+    normalize_msi_summary cfengine-nova.msi "$REVISION"
 }
 
 # package() - Main packaging function that creates the MSI installer

ci/cfengine-build-host-setup.cf

@@ -91,6 +91,10 @@ bundle agent cfengine_build_host_setup
       "wixl";
       "msitools";
 
+      # build-scripts/package-msi derives deterministic MSI GUIDs with uuidgen
+      # (uuid-runtime) for reproducible builds. See ENT-13792.
+      "uuid-runtime";
+
       "binfmt-support"
         comment => "update-binfmts command needed for build-scripts/package-msi script";
 

ci/fix-buildhost.sh

@@ -75,12 +75,13 @@ if [ -f /etc/os-release ]; then
 fi
 
 # MinGW hosts build the MSI with wixl (build-scripts/package-msi) and inspect it
-# with msiinfo (msitools). Installed by the build-host-setup policy at image
-# time; install here too so not-yet-reimaged mingw hosts get them without a
-# reimage. See ENT-13868.
+# with msiinfo (msitools). uuidgen (uuid-runtime) derives deterministic MSI
+# GUIDs for reproducible builds (ENT-13792). Installed by the build-host-setup
+# policy at image time; install here too so not-yet-reimaged mingw hosts get
+# them without a reimage. See ENT-13868.
 if [ -f /etc/cfengine-mingw-build-host.flag ]; then
-  if ! command -v wixl >/dev/null 2>&1 || ! command -v msiinfo >/dev/null 2>&1; then
+  if ! command -v wixl >/dev/null 2>&1 || ! command -v msiinfo >/dev/null 2>&1 || ! command -v uuidgen >/dev/null 2>&1; then
     sudo apt-get update
-    sudo DEBIAN_FRONTEND=noninteractive apt-get install -y wixl msitools
+    sudo DEBIAN_FRONTEND=noninteractive apt-get install -y wixl msitools uuid-runtime
   fi
 fi

container/Dockerfile.mingw

@@ -8,7 +8,7 @@ RUN apt-get update && apt-get install -y \
     autoconf automake binutils bison build-essential curl debhelper dpkg-dev \
     expat fakeroot flex gdb git libexpat1-dev libmodule-load-conditional-perl \
     libpam0g-dev libtool libncurses6 libncurses-dev pkg-config psmisc \
-    python3-pip rsync sudo systemd-coredump unzip wget \
+    python3-pip rsync sudo systemd-coredump unzip uuid-runtime wget \
     && rm -rf /var/lib/apt/lists/*
 
 # MinGW-w64 cross toolchain.

packaging/cfengine-nova/cfengine-nova.wxs

@@ -26,7 +26,9 @@
 	 <?endif?>
    <?endif?>
 
-   <Product Id='*' Name='CFEngine Nova' Language='1033'
+   <!-- ProductCode is pinned (not '*') so rebuilds of the same version are
+        byte-reproducible; package-msi derives it deterministically. ENT-13792 -->
+   <Product Id='$(var.CfProductCode)' Name='CFEngine Nova' Language='1033'
             Version='$(var.CfVersion)' Manufacturer='Northern.tech AS' UpgradeCode='B883FBCC-6F05-4AFA-98FA-CAF09BF464EA' >
 
       <Package Description='CFEngine Nova'
@@ -262,11 +264,16 @@
 	<!-- The sequence numbers are weird to avoid collisions with built-in numbers -->
 
    <InstallExecuteSequence>
-     <RemoveExistingProducts Sequence='1450' />
      <InstallInitialize Sequence='1500' />
 	 <Custom Action='GenerateKey' After='InstallFiles'>NOT Installed</Custom>
 
 	 <InstallFinalize Sequence='6600' />
+
+	 <!-- After InstallFinalize: install new files first, then remove the old
+	      product, so equal-versioned shared DLLs survive via refcounting. Early
+	      placement deletes them and breaks upgrades. Ref:
+	      https://learn.microsoft.com/en-us/windows/win32/msi/removeexistingproducts-action -->
+	 <RemoveExistingProducts Sequence='6700' />
    </InstallExecuteSequence>
 
    </Product>