windows build: calculate COFF checksum ourselves

contrib/build-wine/build-electrum-git.sh

@@ -15,17 +15,17 @@ PYTHON="wine $PYHOME/python.exe -OO -B"
 # Let's begin!
 set -e
 
-mkdir -p tmp
-cd tmp
+here="$(dirname "$(readlink -e "$0")")"
 
-pushd $WINEPREFIX/drive_c/electrum
+. "$CONTRIB"/build_tools_util.sh
 
-# Load electrum-locale for this release
-git submodule init
-git submodule update
+pushd $WINEPREFIX/drive_c/electrum
 
 VERSION=`git describe --tags --dirty --always`
-echo "Last commit: $VERSION"
+info "Last commit: $VERSION"
+
+# Load electrum-locale for this release
+git submodule update --init
 
 pushd ./contrib/deterministic-build/electrum-locale
 if ! which msgfmt > /dev/null 2>&1; then
@@ -41,24 +41,21 @@ popd
 find -exec touch -d '2000-11-11T11:11:11+00:00' {} +
 popd
 
-cp -f ../../../LICENSE .
-
 # Install frozen dependencies
-$PYTHON -m pip install -r ../../deterministic-build/requirements.txt
+$PYTHON -m pip install --no-warn-script-location -r "$CONTRIB"/deterministic-build/requirements.txt
 
-$PYTHON -m pip install -r ../../deterministic-build/requirements-hw.txt
+$PYTHON -m pip install --no-warn-script-location -r "$CONTRIB"/deterministic-build/requirements-hw.txt
 
 pushd $WINEPREFIX/drive_c/electrum
 # see https://github.com/pypa/pip/issues/2195 -- pip makes a copy of the entire directory
 info "Pip installing Electrum. This might take a long time if the project folder is large."
 $PYTHON -m pip install --no-warn-script-location .
 popd
 
-cd ..
-
 rm -rf dist/
 
 # build standalone and portable versions
+info "Running pyinstaller..."
 wine "$PYHOME/scripts/pyinstaller.exe" --noconfirm --ascii --clean --name $NAME_ROOT-$VERSION -w deterministic.spec
 
 # set timestamps in dist, in order to make the installer reproducible
@@ -74,5 +71,42 @@ cd dist
 mv  $NAME_ROOT-setup.exe $NAME_ROOT-$VERSION-setup.exe
 cd ..
 
+info "Padding binaries to 8-byte boundaries, and fixing COFF image checksum in PE header"
+# note: 8-byte boundary padding is what osslsigncode uses:
+#       https://github.com/mtrojnar/osslsigncode/blob/6c8ec4427a0f27c145973450def818e35d4436f6/osslsigncode.c#L3047
+(
+    cd dist
+    for binary_file in ./*.exe; do
+        info ">> fixing $binary_file..."
+        # code based on https://github.com/erocarrera/pefile/blob/bbf28920a71248ed5c656c81e119779c131d9bd4/pefile.py#L5877
+        python3 <<EOF
+pe_file = "$binary_file"
+with open(pe_file, "rb") as f:
+    binary = bytearray(f.read())
+pe_offset = int.from_bytes(binary[0x3c:0x3c+4], byteorder="little")
+checksum_offset = pe_offset + 88
+checksum = 0
+# Pad data to 8-byte boundary.
+remainder = len(binary) % 8
+binary += bytes(8 - remainder)
+for i in range(len(binary) // 4):
+    if i == checksum_offset // 4:  # Skip the checksum field
+        continue
+    dword = int.from_bytes(binary[i*4:i*4+4], byteorder="little")
+    checksum = (checksum & 0xffffffff) + dword + (checksum >> 32)
+    if checksum > 2 ** 32:
+        checksum = (checksum & 0xffffffff) + (checksum >> 32)
+checksum = (checksum & 0xffff) + (checksum >> 16)
+checksum = (checksum) + (checksum >> 16)
+checksum = checksum & 0xffff
+checksum += len(binary)
+# Set the checksum
+binary[checksum_offset : checksum_offset + 4] = int.to_bytes(checksum, byteorder="little", length=4)
+with open(pe_file, "wb") as f:
+    f.write(binary)
+EOF
+    done
+)
+
 echo "Done."
 sha256sum dist/electrum*exe