Create mbedtls_cf_size_if function
Add a constant-time function with size_t parameter for choosing
between two integer values, like the ?: ternary operator.
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/constant_time.c b/library/constant_time.c
index 9ddd21d..aa291d7 100644
--- a/library/constant_time.c
+++ b/library/constant_time.c
@@ -295,6 +295,12 @@
return( ( mask & if1 ) | (~mask & if0 ) );
}
+size_t mbedtls_cf_size_if( unsigned cond, size_t if1, size_t if0 )
+{
+ size_t mask = mbedtls_cf_size_mask( cond );
+ return( ( mask & if1 ) | (~mask & if0 ) );
+}
+
/**
* Select between two sign values in constant-time.
*
diff --git a/library/constant_time.h b/library/constant_time.h
index a8d142b..fdbaf1f 100644
--- a/library/constant_time.h
+++ b/library/constant_time.h
@@ -59,6 +59,8 @@
unsigned mbedtls_cf_uint_if( unsigned cond, unsigned if1, unsigned if0 );
+size_t mbedtls_cf_size_if( unsigned cond, size_t if1, size_t if0 );
+
int mbedtls_cf_cond_select_sign( int a, int b, unsigned char second );
#if defined(MBEDTLS_BIGNUM_C)