Do not read if output pointer is NULL
Skip reading if output pointer is NULL even if the length of the input buffer is 0.
The memory sanitizer will mark this as an error.
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/bignum_core.c b/library/bignum_core.c
index f250009..d5db4b0 100644
--- a/library/bignum_core.c
+++ b/library/bignum_core.c
@@ -171,10 +171,12 @@
return( MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL );
if( X != NULL )
+ {
memset( X, 0, nx * ciL );
- for( i = 0; i < buflen; i++ )
- X[i / ciL] |= ((mbedtls_mpi_uint) buf[i]) << ((i % ciL) << 3);
+ for( i = 0; i < buflen; i++ )
+ X[i / ciL] |= ((mbedtls_mpi_uint) buf[i]) << ((i % ciL) << 3);
+ }
return( 0 );
}
@@ -192,18 +194,20 @@
return( MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL );
if( X != NULL )
+ {
memset( X, 0, nx * ciL );
- overhead = ( nx * ciL ) - buflen;
+ overhead = ( nx * ciL ) - buflen;
- /* Avoid calling `memcpy` with NULL source or destination argument,
- * even if buflen is 0. */
- if( buf != NULL )
- {
- Xp = (unsigned char*) X;
- memcpy( Xp + overhead, buf, buflen );
+ /* Avoid calling `memcpy` with NULL source or destination argument,
+ * even if buflen is 0. */
+ if( buf != NULL && X != NULL )
+ {
+ Xp = (unsigned char*) X;
+ memcpy( Xp + overhead, buf, buflen );
- mbedtls_mpi_core_bigendian_to_host( X, nx );
+ mbedtls_mpi_core_bigendian_to_host( X, nx );
+ }
}
return( 0 );