TLV with arbitrary length fields

git-svn-id: https://joinup.ec.europa.eu/svn/mocca/trunk@912 8a26b1a7-26f0-462f-b9ef-d0e30c41f5a4

2 files changed, 23 insertions, 8 deletions

diff --git a/smcc/src/main/java/at/gv/egiz/smcc/util/TLV.java b/smcc/src/main/java/at/gv/egiz/smcc/util/TLV.java
index b67fe3fa..1e158e75 100644
--- a/smcc/src/main/java/at/gv/egiz/smcc/util/TLV.java
+++ b/smcc/src/main/java/at/gv/egiz/smcc/util/TLV.java
@@ -20,10 +20,10 @@ package at.gv.egiz.smcc.util;
  */
 
 public class TLV {
-  
+
   private byte[] bytes;
   private int start;
-  
+
   public TLV(byte[] bytes, int start) {
     if (bytes.length - start < 2) {
       throw new IllegalArgumentException("TLV must at least consit of tag and length.");
@@ -39,11 +39,28 @@ public class TLV {
     return 0xFF & bytes[start];
   }
 
+	public int getLengthFieldLength() {
+		if ((bytes[start + 1] & 0x80) > 0) {
+			// ISO 7816 allows length fields of up to 5 bytes
+			return 1 + (bytes[start + 1] & 0x07);
+		}
+		return 1;
+	}
+
   /**
    * @return the length
    */
   public int getLength() {
-    return 0xFF & bytes[start + 1];
+
+		if ((bytes[start + 1] & 0x80) > 0) {
+			int length = 0;
+			for (int i = 0; i < (bytes[start + 1] & 0x07); i++) {
+				length <<= 8;
+				length += bytes[start + 2 + i] & 0xff;
+			}
+			return length;
+		}
+		return bytes[start + 1] & 0x7f;
   }
 
   /**
@@ -51,7 +68,7 @@ public class TLV {
    */
   public byte[] getValue() {
     byte[] value = new byte[getLength()];
-    System.arraycopy(bytes, start + 2, value, 0, value.length);
+    System.arraycopy(bytes, start + 1 + getLengthFieldLength(), value, 0, value.length);
     return value;
   }
 
@@ -62,7 +79,7 @@ public class TLV {
   public String toString() {
     return "Tag = " + Integer.toHexString(getTag()) + ", Length = " + getLength() + ", Value = " + toString(getValue());
   }
-  
+
   public static String toString(byte[] b) {
     StringBuffer sb = new StringBuffer();
     sb.append('[');
@@ -79,6 +96,4 @@ public class TLV {
     return sb.toString();
   }
 
-  
-
 }
diff --git a/smcc/src/main/java/at/gv/egiz/smcc/util/TLVSequence.java b/smcc/src/main/java/at/gv/egiz/smcc/util/TLVSequence.java
index 2409f212..00639545 100644
--- a/smcc/src/main/java/at/gv/egiz/smcc/util/TLVSequence.java
+++ b/smcc/src/main/java/at/gv/egiz/smcc/util/TLVSequence.java
@@ -63,7 +63,7 @@ public class TLVSequence implements Iterable<TLV> {
     public TLV next() {
       if (hasNext()) {
         TLV tlv = new TLV(bytes, pos);
-        pos += tlv.getLength() + 2;
+        pos += 1 + tlv.getLengthFieldLength() + tlv.getLength();
         return tlv;
       } else {
         throw new NoSuchElementException();