/* BEGIN_HEADER */
/** \file test_suite_constant_time.function
 *
 * Functional testing of functions in the constant_time module.
 *
 * The tests are instrumented with #TEST_CF_SECRET and #TEST_CF_PUBLIC
 * (see tests/include/test/constant_flow.h) so that running the tests
 * under MSan or Valgrind will detect a non-constant-time implementation.
 */

#include <mbedtls/constant_time.h>
#include <constant_time_internal.h>
#include <constant_time_invasive.h>

#include <test/constant_flow.h>
/* END_HEADER */

/* BEGIN_CASE depends_on:MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC:MBEDTLS_TEST_HOOKS */
void ssl_cf_memcpy_offset(int offset_min, int offset_max, int len)
{
    unsigned char *dst = NULL;
    unsigned char *src = NULL;
    size_t src_len = offset_max + len;
    size_t secret;

    TEST_CALLOC(dst, len);
    TEST_CALLOC(src, src_len);

    /* Fill src in a way that we can detect if we copied the right bytes */
    mbedtls_test_rnd_std_rand(NULL, src, src_len);

    for (secret = offset_min; secret <= (size_t) offset_max; secret++) {
        mbedtls_test_set_step((int) secret);

        TEST_CF_SECRET(&secret, sizeof(secret));
        mbedtls_ct_memcpy_offset(dst, src, secret,
                                 offset_min, offset_max, len);
        TEST_CF_PUBLIC(&secret, sizeof(secret));
        TEST_CF_PUBLIC(dst, len);

        TEST_MEMORY_COMPARE(dst, len, src + secret, len);
    }

exit:
    mbedtls_free(dst);
    mbedtls_free(src);
}
/* END_CASE */