Check for zero length and NULL buffer pointer.

jainvikas8 · jainvikas8 · commit 52fa174a5a05 · 2019-09-04T11:31:35.000+01:00
In reference to issue #49
diff --git a/library/platform_util.c b/library/platform_util.c
@@ -72,7 +72,10 @@ static void * (* const volatile memset_func)( void *, int, size_t ) = memset;
 
 void mbedtls_platform_zeroize( void *buf, size_t len )
 {
-    memset_func( buf, 0, len );
+    MBEDTLS_INTERNAL_VALIDATE( len == 0 || buf != NULL );
+
+    if( len > 0 )
+        memset_func( buf, 0, len );
 }
 #endif /* MBEDTLS_PLATFORM_ZEROIZE_ALT */
 

Original file line number	Diff line number	Diff line change
`@@ -72,7 +72,10 @@ static void * (* const volatile memset_func)( void *, int, size_t ) = memset;`
`72`	`72`
`73`	`73`	`void mbedtls_platform_zeroize( void *buf, size_t len )`
`74`	`74`	`{`
`75`		`- memset_func( buf, 0, len );`
	`75`	`+ MBEDTLS_INTERNAL_VALIDATE( len == 0 \|\| buf != NULL );`
	`76`	`+`
	`77`	`+ if( len > 0 )`
	`78`	`+ memset_func( buf, 0, len );`
`76`	`79`	`}`
`77`	`80`	`#endif /* MBEDTLS_PLATFORM_ZEROIZE_ALT */`
`78`	`81`