From 5f6bdef7604cd9e787da1d9ebd55d1d660ad98e3 Mon Sep 17 00:00:00 2001
From: Erik Nellessen <erik.nellessen@kococonnector.com>
Date: Fri, 8 Nov 2019 15:28:34 +0100
Subject: [PATCH] \#13: Add possibility to add large constructed TLV elements
 to BerTlvBuilder

---
 .../com/payneteasy/tlv/BerTlvBuilder.java     | 17 +++++++---
 .../com/payneteasy/tlv/BerTlvBuilderTest.java | 34 +++++++++++++++++++
 2 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/src/main/java/com/payneteasy/tlv/BerTlvBuilder.java b/src/main/java/com/payneteasy/tlv/BerTlvBuilder.java
index f9857b4..e052c21 100644
--- a/src/main/java/com/payneteasy/tlv/BerTlvBuilder.java
+++ b/src/main/java/com/payneteasy/tlv/BerTlvBuilder.java
@@ -39,19 +39,27 @@ public BerTlvBuilder(BerTag aTemplate, byte[] aBuffer, int aOffset, int aLength)
     }
 
     public static BerTlvBuilder from(BerTlv aTlv) {
+        return from(aTlv, DEFAULT_SIZE);
+    }
+
+    public static BerTlvBuilder from(BerTlv aTlv, int bufferSize) {
         if(aTlv.isConstructed()) {
-            BerTlvBuilder builder = template(aTlv.getTag());
+            BerTlvBuilder builder = template(aTlv.getTag(), bufferSize);
             for (BerTlv tlv : aTlv.theList) {
                 builder.addBerTlv(tlv);
             }
             return builder;
         } else {
-            return new BerTlvBuilder().addBerTlv(aTlv);
+            return new BerTlvBuilder(null, new byte[bufferSize], 0, bufferSize).addBerTlv(aTlv);
         }
     }
 
     public static BerTlvBuilder template(BerTag aTemplate) {
-        return new BerTlvBuilder(aTemplate);
+        return template(aTemplate, DEFAULT_SIZE);
+    }
+
+    public static BerTlvBuilder template(BerTag aTemplate, int bufferSize) {
+        return new BerTlvBuilder(aTemplate, new byte[bufferSize], 0, bufferSize);
     }
 
     public BerTlvBuilder addEmpty(BerTag aObject) {
@@ -191,7 +199,7 @@ public BerTlvBuilder add(BerTlvBuilder aBuilder) {
 
     public BerTlvBuilder addBerTlv(BerTlv aTlv) {
         if(aTlv.isConstructed()) {
-            return add(from(aTlv));
+            return add(from(aTlv, theBuffer.length));
         } else {
             return addBytes(aTlv.getTag(), aTlv.getBytesValue());
         }
@@ -252,4 +260,3 @@ public BerTlvs buildTlvs() {
     private final byte[] theBuffer;
     private final BerTag theTemplate;
 }
-
diff --git a/src/test/java/com/payneteasy/tlv/BerTlvBuilderTest.java b/src/test/java/com/payneteasy/tlv/BerTlvBuilderTest.java
index a10544e..d5fc406 100644
--- a/src/test/java/com/payneteasy/tlv/BerTlvBuilderTest.java
+++ b/src/test/java/com/payneteasy/tlv/BerTlvBuilderTest.java
@@ -3,6 +3,7 @@
 import org.junit.Assert;
 import org.junit.Test;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
@@ -184,6 +185,39 @@ public void testBigData() {
         Assert.assertEquals(1, berTlvs.getList().size());
     }
 
+    @Test
+    public void test_large_value_with_error() {
+        try {
+            BerTlvBuilder builder = new BerTlvBuilder();
+            BerTlv berTlv = new BerTlv(new BerTag(0x82), new byte[6 * 1024]);
+            builder.addBerTlv(berTlv);
+            Assert.fail("Should throw ArrayIndexOutOfBoundsException because default buffer size is 5KB");
+        } catch (ArrayIndexOutOfBoundsException e) {
+            Assert.assertNull(e.getMessage());
+        }
+    }
+
+    @Test
+    public void test_large_value() {
+        final int     sixKilobytes = 6 * 1024;
+        final int     tagLength    = 1;
+        final int     valueLength  = 3;
+        final int     sequenceHeaderSize = 4;
+        final int     bufferSize   = sequenceHeaderSize + sixKilobytes + tagLength + valueLength;
+
+        BerTlv sequenceContent = new BerTlv(new BerTag(0x82), new byte[sixKilobytes]);
+        ArrayList<BerTlv> berTlvs = new ArrayList<BerTlv>();
+        berTlvs.add(sequenceContent);
+        BerTlv sequence = new BerTlv(new BerTag(0x30),
+                                     berTlvs);
+
+        BerTlvBuilder builder = new BerTlvBuilder(null, new byte[bufferSize], 0, bufferSize);
+        builder.addBerTlv(sequence);
+
+        byte[] bytes = builder.buildArray();
+        Assert.assertEquals(bufferSize, bytes.length);
+    }
+
     @Test
     public void test_empty() {
         BerTlv tlv = new BerTlv(new BerTag(0x01), new byte[]{});