Fixes for MSVC warnings

Also added a couple of missing comment blocks.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
This commit is contained in:
Paul Elliott 2021-02-25 12:28:49 +00:00
parent b4e4bfdd00
commit 3e7908189a

View file

@ -65,6 +65,9 @@ static const unsigned char base64_dec_map[128] =
#define BASE64_SIZE_T_MAX ( (size_t) -1 ) /* SIZE_T_MAX is not standard */ #define BASE64_SIZE_T_MAX ( (size_t) -1 ) /* SIZE_T_MAX is not standard */
/*
* Constant flow conditional assignment
*/
static void mbedtls_base64_cond_assign(unsigned char * dest, const unsigned char * const src, static void mbedtls_base64_cond_assign(unsigned char * dest, const unsigned char * const src,
unsigned char condition) unsigned char condition)
{ {
@ -75,19 +78,31 @@ static void mbedtls_base64_cond_assign(unsigned char * dest, const unsigned char
} }
/* /*
* Constant time check for equality * Constant flow check for equality
*/ */
static unsigned char mbedtls_base64_eq(uint32_t in_a, uint32_t in_b) static unsigned char mbedtls_base64_eq(size_t in_a, size_t in_b)
{ {
uint32_t difference = in_a ^ in_b; uint32_t difference = in_a ^ in_b;
/* MSVC has a warning about unary minus on unsigned integer types,
* but this is well-defined and precisely what we want to do here. */
#if defined(_MSC_VER)
#pragma warning( push )
#pragma warning( disable : 4146 )
#endif
difference |= -difference; difference |= -difference;
#if defined(_MSC_VER)
#pragma warning( pop )
#endif
difference >>= 31; difference >>= 31;
return (unsigned char) ( 1 ^ difference ); return (unsigned char) ( 1 ^ difference );
} }
/* /*
* Constant time lookup into table. * Constant flow lookup into table.
*/ */
static unsigned char mbedtls_base64_table_lookup(const unsigned char * const table, static unsigned char mbedtls_base64_table_lookup(const unsigned char * const table,
const size_t table_size, const size_t table_index) const size_t table_size, const size_t table_index)