OpenSSL hexdigest raises error with empty key #2854

OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('md5'), "", "foo")
=> "4acb10ca3965a14a080297db0921950c"

OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('md5'), "", "foo")
raises error

Java::JavaLang::IllegalArgumentException: Empty key
    from javax.crypto.spec.SecretKeySpec.<init>(SecretKeySpec.java:96)
    from org.jruby.ext.openssl.HMAC.initialize(HMAC.java:142)
    from org.jruby.ext.openssl.HMAC$INVOKER$i$2$0$initialize.call(HMAC$INVOKER$i$2$0$initialize.gen)
    from org.jruby.internal.runtime.methods.JavaMethod$JavaMethodTwoOrN.call(JavaMethod.java:822)
    from org.jruby.runtime.callsite.CachingCallSite.callBlock(CachingCallSite.java:211)
    from org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:217)
    from org.jruby.RubyClass.newInstance(RubyClass.java:863)
    from org.jruby.RubyClass$INVOKER$i$newInstance.call(RubyClass$INVOKER$i$newInstance.gen)
    from org.jruby.internal.runtime.methods.JavaMethod$JavaMethodZeroOrOneOrTwoOrNBlock.call(JavaMethod.java:314)
    from org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:346)
    from org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:204)
    from org.jruby.ast.CallTwoArgNode.interpret(CallTwoArgNode.java:59)
    from org.jruby.ast.NewlineNode.interpret(NewlineNode.java:105)
    from org.jruby.ast.RootNode.interpret(RootNode.java:129)
    from org.jruby.evaluator.ASTInterpreter.INTERPRET_EVAL(ASTInterpreter.java:95)
    from org.jruby.evaluator.ASTInterpreter.evalWithBinding(ASTInterpreter.java:184)
... 120 levels...
    from org.jruby.ast.BlockNode.interpret(BlockNode.java:71)
    from org.jruby.evaluator.ASTInterpreter.INTERPRET_METHOD(ASTInterpreter.java:74)
    from org.jruby.internal.runtime.methods.InterpretedMethod.call(InterpretedMethod.java:139)
    from org.jruby.internal.runtime.methods.DefaultMethod.call(DefaultMethod.java:187)
    from org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:306)
    from org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:136)
    from script.console.__file__(script/console:7)
    from script.console.load(script/console)
    from org.jruby.Ruby.runScript(Ruby.java:866)
    from org.jruby.Ruby.runScript(Ruby.java:859)
    from org.jruby.Ruby.runNormally(Ruby.java:728)
    from org.jruby.Ruby.runFromMain(Ruby.java:577)
    from org.jruby.Main.doRunFromMain(Main.java:395)
    from org.jruby.Main.internalRun(Main.java:290)
    from org.jruby.Main.run(Main.java:217)
    from org.jruby.Main.main(Main.java:197)jruby-1.7.19