New helper function to allocate and read a modulus
When including <test/bignum_helpers.h>, the library/ directory now needs to
be on the include path.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/include/test/bignum_helpers.h b/tests/include/test/bignum_helpers.h
index 22ce7f7..ab3c86a 100644
--- a/tests/include/test/bignum_helpers.h
+++ b/tests/include/test/bignum_helpers.h
@@ -30,6 +30,7 @@
#if defined(MBEDTLS_BIGNUM_C)
#include <mbedtls/bignum.h>
+#include <bignum_mod.h>
/** Allocate and populate a core MPI from a test case argument.
*
@@ -54,6 +55,25 @@
int mbedtls_test_read_mpi_core( mbedtls_mpi_uint **pX, size_t *plimbs,
const char *input );
+/** Read a modulus from a hexadecimal string.
+ *
+ * This function allocates exactly as many limbs as necessary to fit
+ * the length of the input. In other words, it preserves leading zeros.
+ *
+ * The limb array is allocated with mbedtls_calloc() and must later be
+ * freed with mbedtls_free().
+ *
+ * \param[in,out] N A modulus structure. It must be initialized, but
+ * not set up.
+ * \param[in] s The null-terminated hexadecimal string to read from.
+ * \param int_rep The desired representation of residues.
+ *
+ * \return \c 0 on success, an \c MBEDTLS_ERR_MPI_xxx error code otherwise.
+ */
+int mbedtls_test_read_mpi_modulus( mbedtls_mpi_mod_modulus *N,
+ const char *s,
+ mbedtls_mpi_mod_rep_selector int_rep );
+
/** Read an MPI from a hexadecimal string.
*
* Like mbedtls_mpi_read_string(), but with tighter guarantees around