commit 057daa3b284d9be70484d8689b2f4896cf450c52
author Piotr Nowicki <piotr.nowicki@arm.com> Mon Aug 03 13:08:33 2020 +0200
committer Piotr Nowicki <piotr.nowicki@arm.com> Tue Aug 11 16:41:34 2020 +0200
tree 4fe711c97587a4b0ef2157d3ef557301488072db
parent 77b7a7754c09a5f2cc48007fefa12cf7adbc2d05

Random delay can be disabled in configuration

Use random delay depending on whether MBEDTLS_FI_COUNTERMEASURES is defined

Signed-off-by: Piotr Nowicki <piotr.nowicki@arm.com>

library/platform_util.c

diff --git a/library/platform_util.c b/library/platform_util.c
index 641172a..3fa9437 100644
--- a/library/platform_util.c
+++ b/library/platform_util.c
@@ -255,6 +255,7 @@
 
 void mbedtls_platform_random_delay( void )
 {
+#if defined(MBEDTLS_FI_COUNTERMEASURES)
     uint32_t rn_1, rn_2, rn_3;
     volatile size_t i = 0;
     uint8_t shift;
@@ -276,6 +277,9 @@
             rn_3 = ( rn_3 << shift ) | ( rn_3 >> ( 32 - shift ) );
         rn_2 ^= rn_3;
     } while( i < rn_1 || rn_2 == 0 || rn_3 == 0 );
+
+#endif /* MBEDTLS_FI_COUNTERMEASURES */
+    return;
 }
 
 #if defined(MBEDTLS_HAVE_TIME_DATE) && !defined(MBEDTLS_PLATFORM_GMTIME_R_ALT)