New test helper mbedtls_test_read_mpi
This test helper reads an MPI from a string and guarantees control over the
number of limbs of the MPI, allowing test cases to construct values with or
without leading zeros, including 0 with 0 limbs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index ae207fd..5a8e211 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -46,6 +46,10 @@
#include <strings.h>
#endif
+#if defined(MBEDTLS_BIGNUM_C)
+#include "mbedtls/bignum.h"
+#endif
+
#if defined(MBEDTLS_THREADING_C) && defined(MBEDTLS_THREADING_PTHREAD) && \
defined(MBEDTLS_TEST_HOOKS)
#include "mbedtls/threading.h"
@@ -847,6 +851,21 @@
return ret;
}
+#if defined(MBEDTLS_BIGNUM_C)
+int mbedtls_test_read_mpi( mbedtls_mpi *X, int radix, const char *s )
+{
+ /* mbedtls_mpi_read_string() currently retains leading zeros.
+ * It always allocates at least one limb for the value 0. */
+ if( s[0] == 0 )
+ {
+ mbedtls_mpi_free( X );
+ return( 0 );
+ }
+ else
+ return( mbedtls_mpi_read_string( X, radix, s ) );
+}
+#endif /* MBEDTLS_BIGNUM_C */
+
#if defined(MBEDTLS_TEST_MUTEX_USAGE)
/** Mutex usage verification framework.
*