From 42c3ccf36e86972bff3a74c1e74c11311e6a7af0 Mon Sep 17 00:00:00 2001
From: Paul Bakker <p.j.bakker@polarssl.org>
Date: Mon, 19 Aug 2013 14:29:31 +0200
Subject: [PATCH] Fixed potential negative value misinterpretation in
 load_file()

---
 library/x509parse.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/library/x509parse.c b/library/x509parse.c
index 535b18075..0a3b6fea2 100644
--- a/library/x509parse.c
+++ b/library/x509parse.c
@@ -1917,14 +1917,21 @@ int x509parse_crl( x509_crl *chain, const unsigned char *buf, size_t buflen )
 static int load_file( const char *path, unsigned char **buf, size_t *n )
 {
     FILE *f;
+    long size;
 
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( POLARSSL_ERR_X509_FILE_IO_ERROR );
 
     fseek( f, 0, SEEK_END );
-    *n = (size_t) ftell( f );
+    if( ( size = ftell( f ) ) == -1 )
+    {
+        fclose( f );
+        return( POLARSSL_ERR_X509_FILE_IO_ERROR );
+    }
     fseek( f, 0, SEEK_SET );
 
+    *n = (size_t) size;
+
     if( *n + 1 == 0 ||
         ( *buf = (unsigned char *) polarssl_malloc( *n + 1 ) ) == NULL )
     {