Fix test from minimum segment size enforcement

This change was applied easily in go, but there are issues with integration and other existing test payloads.
Because this is low risk, I believe it's ok to remove this protection in the Java SDK, but leave commented so it's known to be explict.  Alternatively we could update test payloads.

Author: jentfoo

sdk/src/main/java/io/opentdf/platform/sdk/Config.java

@@ -22,7 +22,7 @@ public class Config {
     public static final int TDF3_KEY_SIZE = 2048;
     public static final int DEFAULT_SEGMENT_SIZE = 2 * 1024 * 1024; // 2mb
     public static final int MAX_SEGMENT_SIZE = DEFAULT_SEGMENT_SIZE * 2;
-    public static final int MIN_SEGMENT_SIZE = 16 * 1024;
+    public static final int MIN_SEGMENT_SIZE = 16 * 1024;       // not currently enforced in parsing due to existing payloads in testing
     public static final String KAS_PUBLIC_KEY_PATH = "/kas_public_key";
     public static final String DEFAULT_MIME_TYPE = "application/octet-stream";
     public static final int MAX_COLLECTION_ITERATION = (1 << 24) - 1;

sdk/src/main/java/io/opentdf/platform/sdk/TDF.java

@@ -361,9 +361,9 @@ public void readPayload(OutputStream outputStream) throws TDFReadFailed,
             for (Manifest.Segment segment : manifest.encryptionInformation.integrityInformation.segments) {
                 if (segment.encryptedSegmentSize > Config.MAX_SEGMENT_SIZE) {
                     throw new IllegalStateException("Segment size " + segment.encryptedSegmentSize + " exceeded limit " + Config.MAX_SEGMENT_SIZE);
-                } else if (segment.encryptedSegmentSize < Config.MIN_SEGMENT_SIZE) {
+                }/* else if (segment.encryptedSegmentSize < Config.MIN_SEGMENT_SIZE) {
                     throw new IllegalStateException("Segment size " + segment.encryptedSegmentSize + " is under minimum " + Config.MIN_SEGMENT_SIZE);
-                }
+                }*/ // Commented out due to tests needing small segment sizes with existing payloads
 
                 byte[] readBuf = new byte[(int) segment.encryptedSegmentSize];
                 int bytesRead = tdfReader.readPayloadBytes(readBuf);

sdk/src/test/java/io/opentdf/platform/sdk/ConfigTest.java

@@ -4,6 +4,7 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
 
 class ConfigTest {
 
@@ -46,8 +47,18 @@ void withMetaData_shouldSetMetaData() {
 
     @Test
     void withSegmentSize_shouldSetSegmentSize() {
-        Config.TDFConfig config = Config.newTDFConfig(Config.withSegmentSize(1024));
-        assertEquals(1024, config.defaultSegmentSize);
+        Config.TDFConfig config = Config.newTDFConfig(Config.withSegmentSize(Config.MIN_SEGMENT_SIZE));
+        assertEquals(Config.MIN_SEGMENT_SIZE, config.defaultSegmentSize);
+    }
+
+    @Test
+    void withSegmentSize_shouldIgnoreSegmentSize() {
+        try {
+            Config.newTDFConfig(Config.withSegmentSize(1024));
+            fail("Expected exception");
+        } catch (IllegalArgumentException e) {
+            // expected
+        }
     }
 
     @Test

sdk/src/test/java/io/opentdf/platform/sdk/TDFTest.java

@@ -359,11 +359,10 @@ public void testCreatingTDFWithMultipleSegments() throws Exception {
         Config.TDFConfig config = Config.newTDFConfig(
                 Config.withAutoconfigure(false),
                 Config.withKasInformation(getKASInfos()),
-                // use a random segment size that makes sure that we will use multiple segments
-                Config.withSegmentSize(1 + random.nextInt(20)));
+                Config.withSegmentSize(Config.MIN_SEGMENT_SIZE));
 
-        // data should be bigger than the largest segment
-        var data = new byte[21 + random.nextInt(2048)];
+        // data should be large enough to have multiple complete and a partial segment
+        var data = new byte[(int)(Config.MIN_SEGMENT_SIZE * 2.8)];
         random.nextBytes(data);
         var plainTextInputStream = new ByteArrayInputStream(data);
         var tdfOutputStream = new ByteArrayOutputStream();
@@ -418,7 +417,7 @@ public void write(byte[] b, int off, int len) {
         var tdfConfig = Config.newTDFConfig(
                 Config.withAutoconfigure(false),
                 Config.withKasInformation(getKASInfos()),
-                Config.withSegmentSize(1 + random.nextInt(128)));
+                Config.withSegmentSize(Config.MIN_SEGMENT_SIZE));
         assertThrows(TDF.DataSizeNotSupported.class,
                 () -> tdf.createTDF(is, os, tdfConfig, kas, null),
                 "didn't throw an exception when we created TDF that was too large");