[macOS] Added optional code signing capability to the OSX build scripts.

contrib/build-osx/base.sh

@@ -2,6 +2,7 @@
 
 RED='\033[0;31m'
 BLUE='\033[0,34m'
+YELLOW='\033[0;33m'
 NC='\033[0m' # No Color
 function info {
 	printf "\r💬 ${BLUE}INFO:${NC}  ${1}\n"
@@ -10,3 +11,25 @@ function fail {
     printf "\r🗯 ${RED}ERROR:${NC} ${1}\n"
     exit 1
 }
+function warn {
+	printf "\r⚠️  ${YELLOW}WARNING:${NC}  ${1}\n"
+}
+
+function DoCodeSignMaybe { # ARGS: infoName fileOrDirName codesignIdentity
+    infoName="$1"
+    file="$2"
+    identity="$3"
+    deep=""
+    if [ -z "$identity" ]; then
+        # we are ok with them not passing anything -- master script calls us always even if no identity is specified
+        return
+    fi
+    if [ -d "$file" ]; then
+        deep="--deep"
+    fi
+    if [ -z "$infoName" ] || [ -z "$file" ] || [ -z "$identity" ] || [ ! -e "$file" ]; then
+        fail "Argument error to internal function DoCodeSignMaybe()"
+    fi
+    info "Code signing ${infoName}..."
+    codesign -f -v $deep -s "$identity" "$file" || fail "Could not code sign ${infoName}"
+}

contrib/build-osx/make_osx

@@ -17,6 +17,24 @@ VERSION=`git describe --tags --dirty --always`
 
 which brew > /dev/null 2>&1 || fail "Please install brew from https://brew.sh/ to continue"
 
+# Code Signing: See https://developer.apple.com/library/archive/documentation/Security/Conceptual/CodeSigningGuide/Procedures/Procedures.html
+APP_SIGN=""
+if [ -n "$1" ]; then
+    # Test the identity is valid for signing by doing this hack. There is no other way to do this.
+    cp -f /bin/ls ./CODESIGN_TEST
+    codesign -s "$1" --dryrun -f ./CODESIGN_TEST > /dev/null 2>&1
+    res=$?
+    rm -f ./CODESIGN_TEST
+    if ((res)); then
+        fail "Code signing identity \"$1\" appears to be invalid."
+    fi
+    unset res
+    APP_SIGN="$1"
+    info "Code signing enabled using identity \"$APP_SIGN\""
+else
+    warn "Code signing DISABLED. Specify a valid macOS Developer identity installed on the system as the first argument to this script to enable signing."
+fi
+
 info "Installing Python $PYTHON_VERSION"
 export PATH="~/.pyenv/bin:~/.pyenv/shims:~/Library/Python/3.6/bin:$PATH"
 if [ -d "~/.pyenv" ]; then
@@ -54,6 +72,7 @@ info "Downloading libusb..."
 curl https://homebrew.bintray.com/bottles/libusb-1.0.22.el_capitan.bottle.tar.gz | \
 tar xz --directory $BUILDDIR
 cp $BUILDDIR/libusb/1.0.22/lib/libusb-1.0.dylib contrib/build-osx
+DoCodeSignMaybe "libusb" "contrib/build-osx/libusb-1.0.dylib" "$APP_SIGN" # If APP_SIGN is empty will be a noop
 
 info "Building libsecp256k1"
 brew install autoconf automake libtool
@@ -66,6 +85,7 @@ git clean -f -x -q
 make
 popd
 cp $BUILDDIR/secp256k1/.libs/libsecp256k1.0.dylib contrib/build-osx
+DoCodeSignMaybe "libsecp256k1" "contrib/build-osx/libsecp256k1.0.dylib" "$APP_SIGN" # If APP_SIGN is empty will be a noop
 
 
 info "Installing requirements..."
@@ -96,5 +116,14 @@ plutil -insert 'CFBundleURLTypes' \
 	-- dist/$PACKAGE.app/Contents/Info.plist \
 	|| fail "Could not add keys to Info.plist. Make sure the program 'plutil' exists and is installed."
 
+DoCodeSignMaybe "app bundle" "dist/${PACKAGE}.app" "$APP_SIGN" # If APP_SIGN is empty will be a noop
+
 info "Creating .DMG"
 hdiutil create -fs HFS+ -volname $PACKAGE -srcfolder dist/$PACKAGE.app dist/electrum-$VERSION.dmg || fail "Could not create .DMG"
+
+DoCodeSignMaybe ".DMG" "dist/electrum-${VERSION}.dmg" "$APP_SIGN" # If APP_SIGN is empty will be a noop
+
+if [ -z "$APP_SIGN" ]; then
+    warn "App was built successfully but was not code signed. Users may get security warnings from macOS."
+    warn "Specify a valid code signing identity as the first argument to this script to enable code signing."
+fi