commit 073a070590104cc7148d03b4d1969632f57cc5f9
author Sanne Wouda <sanne.wouda@arm.com> Mon Aug 21 15:58:12 2017 +0100
committer Sanne Wouda <sanne.wouda@arm.com> Wed Sep 13 11:52:03 2017 +0100
tree 90d1e67fe818c0bc110d39d159d81956c623cf16
parent 1fe5e8ab44ef46b582ab54db5afcb6bab180d440

Add end-of-buffer check to prevent heap-buffer-overflow

Dereference of *p should not happen when it points past the end of the
buffer.

Internal reference: IOTSSL-1663

library/pkparse.c

diff --git a/library/pkparse.c b/library/pkparse.c
index f0a12f9..e21470b 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -175,6 +175,10 @@
 {
     int ret;
 
+    if ( end - *p < 1 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                MBEDTLS_ERR_ASN1_OUT_OF_DATA );
+
     /* Tag may be either OID or SEQUENCE */
     params->tag = **p;
     if( params->tag != MBEDTLS_ASN1_OID