From 519fd0e4e9ffe721fc11fa4395cc9ec9f313931a Mon Sep 17 00:00:00 2001 From: clemenso Date: Fri, 25 Feb 2011 13:54:20 +0000 Subject: TLV with arbitrary length fields git-svn-id: https://joinup.ec.europa.eu/svn/mocca/trunk@912 8a26b1a7-26f0-462f-b9ef-d0e30c41f5a4 --- smcc/src/main/java/at/gv/egiz/smcc/util/TLV.java | 29 ++++++++++++++++------ .../java/at/gv/egiz/smcc/util/TLVSequence.java | 2 +- 2 files changed, 23 insertions(+), 8 deletions(-) (limited to 'smcc/src/main') 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 { 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(); -- cgit v1.2.3