Abort modular inversion when modulus is one.
The modular inversion function hangs when provided with the modulus 1. This commit refuses this modulus with a BAD_INPUT error code. It also adds a test for this case.
diff --git a/tests/suites/test_suite_mpi.data b/tests/suites/test_suite_mpi.data
index 5d6cf0e..18a9fa0 100644
--- a/tests/suites/test_suite_mpi.data
+++ b/tests/suites/test_suite_mpi.data
@@ -550,6 +550,9 @@
Base test mbedtls_mpi_inv_mod #4
mbedtls_mpi_inv_mod:10:"2":10:"4":10:"0":MBEDTLS_ERR_MPI_NOT_ACCEPTABLE
+Base test mbedtls_mpi_inv_mod #5
+mbedtls_mpi_inv_mod:10:"3":10:"1":10:"0":MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+
Test mbedtls_mpi_inv_mod #1
mbedtls_mpi_inv_mod:16:"aa4df5cb14b4c31237f98bd1faf527c283c2d0f3eec89718664ba33f9762907c":16:"fffbbd660b94412ae61ead9c2906a344116e316a256fd387874c6c675b1d587d":16:"8d6a5c1d7adeae3e94b9bcd2c47e0d46e778bc8804a2cc25c02d775dc3d05b0c":0