Skip multiple CRLF if present.

For unknown reasons, when using the async clients to upload chunked
data, the SDK sometimes inserts multiple CRLFs between chunks.
Skip if we need to.

Fixes #1840
Fixes #1842

server/src/main/java/com/adobe/testing/s3mock/util/AwsChunkedDecodingChecksumInputStream.java

@@ -66,7 +66,7 @@ public AwsChunkedDecodingChecksumInputStream(InputStream source, long decodedLen
   public int read() throws IOException {
     if (chunkLength == 0L) {
       //try to read chunk length
-      var hexLengthBytes = readUntil(DELIMITER);
+      var hexLengthBytes = readHexLength();
       if (hexLengthBytes.length == 0) {
         return -1;
       }
@@ -88,4 +88,8 @@ public int read() throws IOException {
 
     return source.read();
   }
+
+  private byte[] readHexLength() throws IOException {
+    return readUntil(DELIMITER);
+  }
 }

server/src/main/java/com/adobe/testing/s3mock/util/AwsUnsignedChunkedDecodingChecksumInputStream.java

@@ -66,7 +66,7 @@ public AwsUnsignedChunkedDecodingChecksumInputStream(InputStream source, long de
   public int read() throws IOException {
     if (chunkLength == 0L) {
       //try to read chunk length
-      var hexLengthBytes = readUntil(CRLF);
+      var hexLengthBytes = readHexlength();
       if (hexLengthBytes.length == 0) {
         return -1;
       }
@@ -87,4 +87,12 @@ public int read() throws IOException {
 
     return source.read();
   }
+
+  private byte[] readHexlength() throws IOException {
+    var hexLengthBytes = readUntil(CRLF);
+    if (hexLengthBytes.length == 0) {
+      hexLengthBytes = readUntil(CRLF);
+    }
+    return hexLengthBytes;
+  }
 }

server/src/test/java/com/adobe/testing/s3mock/util/DigestUtilTest.java

@@ -1,5 +1,5 @@
 /*
- *  Copyright 2017-2023 Adobe.
+ *  Copyright 2017-2024 Adobe.
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -19,7 +19,6 @@
 import static com.adobe.testing.s3mock.util.TestUtil.getTestFile;
 import static org.assertj.core.api.Assertions.assertThat;
 
-import java.io.IOException;
 import java.util.Arrays;
 import org.apache.commons.codec.digest.DigestUtils;
 import org.apache.commons.lang3.ArrayUtils;
@@ -29,7 +28,7 @@
 class DigestUtilTest {
 
   @Test
-  void testHexDigestOfMultipleFiles(TestInfo testInfo) throws IOException {
+  void testHexDigestOfMultipleFiles(TestInfo testInfo) {
     //yes, this is correct - AWS calculates a Multipart digest by calculating the digest of every
     //file involved, and then calculates the digest on the result.
     //a hyphen with the part count is added as a suffix.