Tests seem to require BC on OpenJDK

acme4j-client/pom.xml

@@ -39,5 +39,11 @@
             <artifactId>slf4j-api</artifactId>
             <version>${slf4j.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.bouncycastle</groupId>
+            <artifactId>bcpg-jdk15on</artifactId>
+            <version>${bouncycastle.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 </project>

acme4j-client/src/test/java/org/shredzone/acme4j/util/SignatureUtilsTest.java

@@ -17,8 +17,11 @@ import static org.hamcrest.Matchers.is;
 import static org.junit.Assert.assertThat;
 
 import java.security.KeyPair;
+import java.security.Security;
 
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.jose4j.jwk.PublicJsonWebKey;
+import org.junit.BeforeClass;
 import org.junit.Test;
 
 /**
@@ -28,6 +31,11 @@ import org.junit.Test;
  */
 public class SignatureUtilsTest {
 
+    @BeforeClass
+    public static void setup() {
+        Security.addProvider(new BouncyCastleProvider());
+    }
+
     /**
      * Test if RSA using SHA-256 keys are properly detected.
      */