Make mbedtls_ssl_cf_memcpy_offset() constant-flow

all.sh component test_valgrind_constant_flow is now passing.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
This commit is contained in:
Manuel Pégourié-Gonnard 2020-08-19 12:35:30 +02:00
parent 73afa37507
commit de1cf2c5e1

View file

@ -314,27 +314,6 @@ int (*mbedtls_ssl_hw_record_read)( mbedtls_ssl_context *ssl ) = NULL;
int (*mbedtls_ssl_hw_record_finish)( mbedtls_ssl_context *ssl ) = NULL;
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
/* The function below is only used in the Lucky 13 counter-measure in
* mbedtls_ssl_decrypt_buf(). These are the defines that guard the call site. */
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) && \
( defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2) )
/* This function makes sure every byte in the memory region is accessed
* (in ascending addresses order) */
static void ssl_read_memory( const unsigned char *p, size_t len )
{
unsigned char acc = 0;
volatile unsigned char force;
for( ; len != 0; p++, len-- )
acc ^= *p;
force = acc;
(void) force;
}
#endif /* SSL_SOME_MODES_USE_MAC && ( TLS1 || TLS1_1 || TLS1_2 ) */
/*
* Encryption/decryption functions
*/
@ -1206,10 +1185,13 @@ MBEDTLS_STATIC_TESTABLE void mbedtls_ssl_cf_memcpy_offset(
size_t offset_min, size_t offset_max,
size_t len )
{
/* WIP - THIS IS NOT ACTUALLY CONSTANT-FLOW!
* This is just to be able to write tests and check they work. */
ssl_read_memory( src_base + offset_min, offset_max - offset_min + len );
memcpy( dst, src_base + offset_secret, len );
size_t offset;
for( offset = offset_min; offset <= offset_max; offset++ )
{
mbedtls_ssl_cf_memcpy_if_eq( dst, src_base + offset, len,
offset, offset_secret );
}
}
#endif /* MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC */