GH-1550: DefaultKafkaHeaderMapper - trust arrays

Resolves #1550

- trust arrays of trusted types (including arrays of primitive wrappers and String))
- trust arrays of primitives

Author: garyrussell

spring-kafka/src/main/java/org/springframework/kafka/support/DefaultKafkaHeaderMapper.java

@@ -21,6 +21,7 @@
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
@@ -62,6 +63,16 @@ public class DefaultKafkaHeaderMapper extends AbstractKafkaHeaderMapper {
 
 	private static final String JAVA_LANG_STRING = "java.lang.String";
 
+	private static final Set<String> TRUSTED_ARRAY_TYPES =
+			new HashSet<>(Arrays.asList(
+					"[B",
+					"[I",
+					"[J",
+					"[F",
+					"[D",
+					"[C"
+			));
+
 	private static final List<String> DEFAULT_TRUSTED_PACKAGES =
 			Arrays.asList(
 					"java.lang",
@@ -366,12 +377,16 @@ protected boolean trusted(String requestedType) {
 		if (requestedType.equals(NonTrustedHeaderType.class.getName())) {
 			return true;
 		}
+		if (TRUSTED_ARRAY_TYPES.contains(requestedType)) {
+			return true;
+		}
+		String type = requestedType.startsWith("[") ? requestedType.substring(2) : requestedType;
 		if (!this.trustedPackages.isEmpty()) {
-			int lastDot = requestedType.lastIndexOf('.');
+			int lastDot = type.lastIndexOf('.');
 			if (lastDot < 0) {
 				return false;
 			}
-			String packageName = requestedType.substring(0, lastDot);
+			String packageName = type.substring(0, lastDot);
 			for (String trustedPackage : this.trustedPackages) {
 				if (packageName.equals(trustedPackage) || packageName.startsWith(trustedPackage + ".")) {
 					return true;

spring-kafka/src/test/java/org/springframework/kafka/support/DefaultKafkaHeaderMapperTests.java

@@ -68,10 +68,23 @@ void testTrustedAndNot() {
 				.setHeader("simpleContentType", MimeTypeUtils.TEXT_PLAIN_VALUE)
 				.setHeader("customToString", new Bar("fiz"))
 				.setHeader("uri", URI.create("https://foo.bar"))
+				.setHeader("intA", new int[] { 42 })
+				.setHeader("longA", new long[] { 42L })
+				.setHeader("floatA", new float[] { 1.0f })
+				.setHeader("doubleA", new double[] { 1.0 })
+				.setHeader("charA", new char[] { 'c' })
+				.setHeader("boolA", new boolean[] { true })
+				.setHeader("IntA", new Integer[] { 42 })
+				.setHeader("LongA", new Long[] { 42L })
+				.setHeader("FloatA", new Float[] { 1.0f })
+				.setHeader("DoubleA", new Double[] { 1.0 })
+				.setHeader("CharA", new Character[] { 'c' })
+				.setHeader("BoolA", new Boolean[] { true })
+				.setHeader("stringA", new String[] { "array" })
 				.build();
 		RecordHeaders recordHeaders = new RecordHeaders();
 		mapper.fromHeaders(message.getHeaders(), recordHeaders);
-		assertThat(recordHeaders.toArray().length).isEqualTo(10); // 9 + json_types
+		assertThat(recordHeaders.toArray().length).isEqualTo(23); // 21 + json_types
 		Map<String, Object> headers = new HashMap<>();
 		mapper.toHeaders(recordHeaders, headers);
 		assertThat(headers.get("foo")).isInstanceOf(byte[].class);
@@ -85,10 +98,21 @@ void testTrustedAndNot() {
 		assertThat(headers.get(MessageHeaders.ERROR_CHANNEL)).isEqualTo("errors");
 		assertThat(headers.get("customToString")).isEqualTo("Bar [field=fiz]");
 		assertThat(headers.get("uri")).isEqualTo(URI.create("https://foo.bar"));
+		assertThat(headers.get("intA")).isEqualTo(new int[] { 42 });
+		assertThat(headers.get("longA")).isEqualTo(new long[] { 42L });
+		assertThat(headers.get("floatA")).isEqualTo(new float[] { 1.0f });
+		assertThat(headers.get("doubleA")).isEqualTo(new double[] { 1.0 });
+		assertThat(headers.get("charA")).isEqualTo(new char[] { 'c' });
+		assertThat(headers.get("IntA")).isEqualTo(new Integer[] { 42 });
+		assertThat(headers.get("LongA")).isEqualTo(new Long[] { 42L });
+		assertThat(headers.get("FloatA")).isEqualTo(new Float[] { 1.0f });
+		assertThat(headers.get("DoubleA")).isEqualTo(new Double[] { 1.0 });
+		assertThat(headers.get("CharA")).isEqualTo(new Character[] { 'c' });
+		assertThat(headers.get("stringA")).isEqualTo(new String[] { "array" });
 		NonTrustedHeaderType ntht = (NonTrustedHeaderType) headers.get("fix");
 		assertThat(ntht.getHeaderValue()).isNotNull();
 		assertThat(ntht.getUntrustedType()).isEqualTo(Foo.class.getName());
-		assertThat(headers).hasSize(9);
+		assertThat(headers).hasSize(22);
 
 		mapper.addTrustedPackages(getClass().getPackage().getName());
 		headers = new HashMap<>();
@@ -97,7 +121,7 @@ void testTrustedAndNot() {
 		assertThat(new String((byte[]) headers.get("foo"))).isEqualTo("bar");
 		assertThat(headers.get("baz")).isEqualTo("qux");
 		assertThat(headers.get("fix")).isEqualTo(new Foo());
-		assertThat(headers).hasSize(9);
+		assertThat(headers).hasSize(22);
 	}
 
 	@Test