Add mbedtls_ct_error_if, with tests

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
This commit is contained in:
Dave Rodgman 2023-09-22 09:43:49 +01:00
parent 9d0869140b
commit fbe74a9e51
4 changed files with 157 additions and 1 deletions

View file

@ -331,7 +331,6 @@ static inline unsigned char mbedtls_ct_uchar_in_range_if(unsigned char low,
return (unsigned char) (~(low_mask | high_mask)) & to;
}
/* ============================================================================
* Everything below here is trivial wrapper functions
*/
@ -397,6 +396,17 @@ static inline mbedtls_mpi_uint mbedtls_ct_mpi_uint_if_else_0(mbedtls_ct_conditio
#endif /* MBEDTLS_BIGNUM_C */
static inline int mbedtls_ct_error_if(mbedtls_ct_condition_t condition, int if1, int if0)
{
return -((int) mbedtls_ct_if(condition, (mbedtls_ct_uint_t) (-if1),
(mbedtls_ct_uint_t) (-if0)));
}
static inline int mbedtls_ct_error_if_else_0(mbedtls_ct_condition_t condition, int if1)
{
return -((int) (condition & (-if1)));
}
static inline mbedtls_ct_condition_t mbedtls_ct_uint_eq(mbedtls_ct_uint_t x,
mbedtls_ct_uint_t y)
{

View file

@ -411,6 +411,35 @@ static inline unsigned char mbedtls_ct_uchar_in_range_if(unsigned char low,
unsigned char c,
unsigned char t);
/** Choose between two error values. The values must be in the range [-32767..0].
*
* Functionally equivalent to:
*
* condition ? if1 : if0.
*
* \param condition Condition to test.
* \param if1 Value to use if \p condition == MBEDTLS_CT_TRUE.
* \param if0 Value to use if \p condition == MBEDTLS_CT_FALSE.
*
* \return \c if1 if \p condition == MBEDTLS_CT_TRUE, otherwise \c if0.
*/
static inline int mbedtls_ct_error_if(mbedtls_ct_condition_t condition, int if1, int if0);
/** Choose between an error value and 0. The error value must be in the range [-32767..0].
*
* Functionally equivalent to:
*
* condition ? if1 : 0.
*
* Functionally equivalent to mbedtls_ct_error_if(condition, if1, 0) but
* results in smaller code size.
*
* \param condition Condition to test.
* \param if1 Value to use if \p condition == MBEDTLS_CT_TRUE.
*
* \return \c if1 if \p condition == MBEDTLS_CT_TRUE, otherwise 0.
*/
static inline int mbedtls_ct_error_if_else_0(mbedtls_ct_condition_t condition, int if1);
/* ============================================================================
* Block memory operations

View file

@ -646,6 +646,102 @@ mbedtls_ct_if:"0xffffffffffffffff":"0xffffffffffffffff":"0x7fffffffffffffff"
mbedtls_ct_if 0xffffffffffffffff 0xffffffffffffffff 0xffffffffffffffff
mbedtls_ct_if:"0xffffffffffffffff":"0xffffffffffffffff":"0xffffffffffffffff"
mbedtls_ct_error_if 0 0 0
mbedtls_ct_error_if:0:0:0
mbedtls_ct_error_if 0 0 -1
mbedtls_ct_error_if:0:0:-1
mbedtls_ct_error_if 0 0 -32766
mbedtls_ct_error_if:0:0:-32766
mbedtls_ct_error_if 0 0 -32767
mbedtls_ct_error_if:0:0:-32767
mbedtls_ct_error_if 0 -1 0
mbedtls_ct_error_if:0:-1:0
mbedtls_ct_error_if 0 -1 -1
mbedtls_ct_error_if:0:-1:-1
mbedtls_ct_error_if 0 -1 -32766
mbedtls_ct_error_if:0:-1:-32766
mbedtls_ct_error_if 0 -1 -32767
mbedtls_ct_error_if:0:-1:-32767
mbedtls_ct_error_if 0 -32766 0
mbedtls_ct_error_if:0:-32766:0
mbedtls_ct_error_if 0 -32766 -1
mbedtls_ct_error_if:0:-32766:-1
mbedtls_ct_error_if 0 -32766 -32766
mbedtls_ct_error_if:0:-32766:-32766
mbedtls_ct_error_if 0 -32766 -32767
mbedtls_ct_error_if:0:-32766:-32767
mbedtls_ct_error_if 0 -32767 0
mbedtls_ct_error_if:0:-32767:0
mbedtls_ct_error_if 0 -32767 -1
mbedtls_ct_error_if:0:-32767:-1
mbedtls_ct_error_if 0 -32767 -32766
mbedtls_ct_error_if:0:-32767:-32766
mbedtls_ct_error_if 0 -32767 -32767
mbedtls_ct_error_if:0:-32767:-32767
mbedtls_ct_error_if 1 0 0
mbedtls_ct_error_if:1:0:0
mbedtls_ct_error_if 1 0 -1
mbedtls_ct_error_if:1:0:-1
mbedtls_ct_error_if 1 0 -32766
mbedtls_ct_error_if:1:0:-32766
mbedtls_ct_error_if 1 0 -32767
mbedtls_ct_error_if:1:0:-32767
mbedtls_ct_error_if 1 -1 0
mbedtls_ct_error_if:1:-1:0
mbedtls_ct_error_if 1 -1 -1
mbedtls_ct_error_if:1:-1:-1
mbedtls_ct_error_if 1 -1 -32766
mbedtls_ct_error_if:1:-1:-32766
mbedtls_ct_error_if 1 -1 -32767
mbedtls_ct_error_if:1:-1:-32767
mbedtls_ct_error_if 1 -32766 0
mbedtls_ct_error_if:1:-32766:0
mbedtls_ct_error_if 1 -32766 -1
mbedtls_ct_error_if:1:-32766:-1
mbedtls_ct_error_if 1 -32766 -32766
mbedtls_ct_error_if:1:-32766:-32766
mbedtls_ct_error_if 1 -32766 -32767
mbedtls_ct_error_if:1:-32766:-32767
mbedtls_ct_error_if 1 -32767 0
mbedtls_ct_error_if:1:-32767:0
mbedtls_ct_error_if 1 -32767 -1
mbedtls_ct_error_if:1:-32767:-1
mbedtls_ct_error_if 1 -32767 -32766
mbedtls_ct_error_if:1:-32767:-32766
mbedtls_ct_error_if 1 -32767 -32767
mbedtls_ct_error_if:1:-32767:-32767
mbedtls_ct_zeroize_if 0x0 0
mbedtls_ct_zeroize_if:"0x0":0

View file

@ -114,6 +114,27 @@ void mbedtls_ct_uchar_in_range_if(int li, int hi, int ti)
}
/* END_CASE */
/* BEGIN_CASE */
void mbedtls_ct_error_if(int cond, int t, int f)
{
mbedtls_ct_condition_t c = mbedtls_ct_bool(cond);
mbedtls_ct_uint_t expected = c ? t : f;
mbedtls_ct_uint_t expected0 = c ? t : 0;
TEST_CF_SECRET(&c, sizeof(c));
TEST_CF_SECRET(&t, sizeof(t));
TEST_CF_SECRET(&f, sizeof(f));
TEST_EQUAL(mbedtls_ct_error_if(c, t, f), expected);
TEST_EQUAL(mbedtls_ct_error_if_else_0(c, t), expected0);
TEST_CF_PUBLIC(&c, sizeof(c));
TEST_CF_PUBLIC(&t, sizeof(t));
TEST_CF_PUBLIC(&f, sizeof(f));
}
/* END_CASE */
/* BEGIN_CASE */
void mbedtls_ct_if(char *c_str, char *t_str, char *f_str)
{