Add checkGradleChecksum.sh to verify gradle jars on CI

Author: ZacSweers

.ci/checkGradleChecksum.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+# First parse the gradle version from its gradle-wrapper.properties file
+GRADLE_WRAPPER_PROPERTIES_FILE=gradle/wrapper/gradle-wrapper.properties
+GRADLE_URL_PREFIX="https\://services.gradle.org/distributions/gradle-"
+GRADLE_URL_SUFFIX="-all.zip"
+
+function prop {
+    grep "${1}" ${GRADLE_WRAPPER_PROPERTIES_FILE}|cut -d'=' -f2
+}
+
+GRADLE_VERSION_URL=$(prop "distributionUrl")
+GRADLE_VERSION_STRIPPED_PREFIX=${GRADLE_VERSION_URL#"$GRADLE_URL_PREFIX"}
+GRADLE_VERSION=${GRADLE_VERSION_STRIPPED_PREFIX%"$GRADLE_URL_SUFFIX"}
+
+# Now compare against gradle's distribution upstream with sha256sum
+echo "Checking Gradle wrapper jar for version: ${GRADLE_VERSION}"
+cd gradle/wrapper
+curl --location --output gradle-wrapper.jar.sha256 \
+       https://services.gradle.org/distributions/gradle-${GRADLE_VERSION}-wrapper.jar.sha256
+echo "  gradle-wrapper.jar" >> gradle-wrapper.jar.sha256
+sha256sum --check gradle-wrapper.jar.sha256
+if [[ $? != 0 ]]; then
+    echo "Gradle wrapper failed checksum verification. Please investigate." >&2
+    exit $?
+fi
+rm gradle-wrapper.jar.sha256
+cd ../..

.travis.yml

@@ -5,6 +5,7 @@ env:
   - NODE_VERSION="6.10.2"
 before_install:
   - nvm install $NODE_VERSION
+  - ./.ci/checkGradleChecksum.sh
 install: true
 script:
   - ./.ci/ci.sh