dexter has uploaded this change for review. (
https://gerrit.osmocom.org/c/android-apdu-proxy/+/41801?usp=email )
Change subject: OmapiCallbackHandlerVpcd: add check to filter short TPDUs
......................................................................
OmapiCallbackHandlerVpcd: add check to filter short TPDUs
Related: OS#6836
Change-Id: I4e76afd7cf4d63c67b1525202fbe74e0796b2ba3
---
M app/src/main/java/org/osmocom/androidApduProxy/OmapiCallbackHandlerVpcd.java
1 file changed, 10 insertions(+), 0 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/android-apdu-proxy
refs/changes/01/41801/1
diff --git
a/app/src/main/java/org/osmocom/androidApduProxy/OmapiCallbackHandlerVpcd.java
b/app/src/main/java/org/osmocom/androidApduProxy/OmapiCallbackHandlerVpcd.java
index f443ac2..b33d28c 100644
---
a/app/src/main/java/org/osmocom/androidApduProxy/OmapiCallbackHandlerVpcd.java
+++
b/app/src/main/java/org/osmocom/androidApduProxy/OmapiCallbackHandlerVpcd.java
@@ -101,6 +101,16 @@
@Override
public byte[] vpcdTransact(byte[] tpdu) {
Log.i("PROXY", "Exchanging TPDU...\n");
+
+ //All TPDUs that we receive here should have a minimum length
of 5 bytes. Under normal conditins, short
+ //TPDUs should not occurr as they should already be filtered
out by the layers that call this method.
+ //To ensure seamless operation, let's check the TPDU length
and reject short TPDUs immediately.
+ if (tpdu.length < 5) {
+ Log.e("PROXY", String.format("Rejecting short TPDU
(%s)...\n", Utils.b2h(tpdu)));
+ //see also ISO/IEC 7816-4, table 5 (wrong length; no
further indication)
+ return (Utils.h2b("6700"));
+ }
+
//In case the TPDU contains a SELECT by DF-Name, which is
forbidden by OMAPI by design, we must
//find an alternative solution: In case the SELECT targets the
currently selected application,
//we just use the FID 7FFF, which is an alias for the
currently selected application. In case the
--
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Gerrit-MessageType: newchange
Gerrit-Project: android-apdu-proxy
Gerrit-Branch: master
Gerrit-Change-Id: I4e76afd7cf4d63c67b1525202fbe74e0796b2ba3
Gerrit-Change-Number: 41801
Gerrit-PatchSet: 1
Gerrit-Owner: dexter <[email protected]>
