commit 5b89c0927366631597ab9a48f430ffd6c603846a
author Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com> Tue Dec 18 10:03:30 2018 +0100
committer Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com> Tue Dec 18 12:22:40 2018 +0100
tree 511c71f8972edd27a4e36430d37d51a5e2c117a9
parent 998a358529faac5b6bfded2d79590bdf2d610579

Add check for iv_off in AES-CFB128 and AES-OFB

The check is mandatory as skipping it results in buffer overread of arbitrary
size.

library/aes.c

diff --git a/library/aes.c b/library/aes.c
index f6dc996..1c743f9 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -1298,6 +1298,9 @@
 
     n = *iv_off;
 
+    if( n > 16 )
+        return( MBEDTLS_ERR_AES_BAD_INPUT_DATA );
+
     if( mode == MBEDTLS_AES_DECRYPT )
     {
         while( length-- )
@@ -1391,6 +1394,9 @@
 
     n = *iv_off;
 
+    if( n > 16 )
+        return( MBEDTLS_ERR_AES_BAD_INPUT_DATA );
+
     while( length-- )
     {
         if( n == 0 )