Bignum Mod: remove endianness from modulus

The external representation before included more than just endianness
(like reading in Mongtomery curve scalars or converting hashes to
numbers in a standard compliant way).

These are higher level concepts and are out of scope for Bignum and for
the modulus structure.

Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/tests/suites/test_suite_bignum_mod.data b/tests/suites/test_suite_bignum_mod.data
index ba7d577..ef9416e 100644
--- a/tests/suites/test_suite_bignum_mod.data
+++ b/tests/suites/test_suite_bignum_mod.data
@@ -1,29 +1,11 @@
-Test mbedtls_mpi_mod_setup #1 (Both representations invalid)
-mpi_mod_setup:MBEDTLS_MPI_MOD_EXT_REP_INVALID:MBEDTLS_MPI_MOD_REP_INVALID:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+Test mbedtls_mpi_mod_setup #1 (Internal representation invalid)
+mpi_mod_setup:MBEDTLS_MPI_MOD_REP_INVALID:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
 
-Test mbedtls_mpi_mod_setup #2 (Internal representation invalid)
-mpi_mod_setup:MBEDTLS_MPI_MOD_EXT_REP_LE:MBEDTLS_MPI_MOD_REP_INVALID:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+Test mbedtls_mpi_mod_setup #6 (Optimised reduction)
+mpi_mod_setup:MBEDTLS_MPI_MOD_REP_OPT_RED:0
 
-Test mbedtls_mpi_mod_setup #3 (Internal representation invalid)
-mpi_mod_setup:MBEDTLS_MPI_MOD_EXT_REP_BE:MBEDTLS_MPI_MOD_REP_INVALID:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
-
-Test mbedtls_mpi_mod_setup #4 (External representation invalid)
-mpi_mod_setup:MBEDTLS_MPI_MOD_EXT_REP_INVALID:MBEDTLS_MPI_MOD_REP_MONTGOMERY:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
-
-Test mbedtls_mpi_mod_setup #5 (External representation invalid)
-mpi_mod_setup:MBEDTLS_MPI_MOD_EXT_REP_INVALID:MBEDTLS_MPI_MOD_REP_OPT_RED:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
-
-Test mbedtls_mpi_mod_setup #6 (Both representations valid)
-mpi_mod_setup:MBEDTLS_MPI_MOD_EXT_REP_BE:MBEDTLS_MPI_MOD_REP_OPT_RED:0
-
-Test mbedtls_mpi_mod_setup #7 (Both representations valid)
-mpi_mod_setup:MBEDTLS_MPI_MOD_EXT_REP_BE:MBEDTLS_MPI_MOD_REP_MONTGOMERY:0
-
-Test mbedtls_mpi_mod_setup #8 (Both representations valid)
-mpi_mod_setup:MBEDTLS_MPI_MOD_EXT_REP_LE:MBEDTLS_MPI_MOD_REP_OPT_RED:0
-
-Test mbedtls_mpi_mod_setup #9 (Both representations valid)
-mpi_mod_setup:MBEDTLS_MPI_MOD_EXT_REP_LE:MBEDTLS_MPI_MOD_REP_MONTGOMERY:0
+Test mbedtls_mpi_mod_setup #7 (Montgomery representation)
+mpi_mod_setup:MBEDTLS_MPI_MOD_REP_MONTGOMERY:0
 
 # BEGIN MERGE SLOT 1
 
diff --git a/tests/suites/test_suite_bignum_mod.function b/tests/suites/test_suite_bignum_mod.function
index 5a75ebc..bb87ba9 100644
--- a/tests/suites/test_suite_bignum_mod.function
+++ b/tests/suites/test_suite_bignum_mod.function
@@ -12,7 +12,7 @@
  */
 
 /* BEGIN_CASE */
-void mpi_mod_setup( int ext_rep, int int_rep, int iret )
+void mpi_mod_setup( int int_rep, int iret )
 {
     #define MLIMBS 8
     mbedtls_mpi_uint mp[MLIMBS];
@@ -22,7 +22,7 @@
     memset( mp, 0xFF, sizeof(mp) );
 
     mbedtls_mpi_mod_modulus_init( &m );
-    ret = mbedtls_mpi_mod_modulus_setup( &m, mp, MLIMBS, ext_rep, int_rep );
+    ret = mbedtls_mpi_mod_modulus_setup( &m, mp, MLIMBS, int_rep );
     TEST_EQUAL( ret, iret );
 
     /* Only test if the constants have been set-up  */
@@ -96,7 +96,7 @@
     TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &R, &r_limbs, input_Y ) );
 
     TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m, N, n_limbs,
-                MBEDTLS_MPI_MOD_EXT_REP_LE, MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
+                MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
 
     TEST_EQUAL( ret, mbedtls_mpi_mod_residue_setup( &r, &m, R , r_limbs ) );
 
@@ -145,7 +145,7 @@
 
     mbedtls_mpi_mod_ext_rep endian = MBEDTLS_MPI_MOD_EXT_REP_LE;
     TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m, N, n_limbs,
-                endian, MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
+                MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
 
     TEST_EQUAL( 0, mbedtls_mpi_mod_residue_setup( &r, &m, R , n_limbs ) );
 
@@ -191,7 +191,7 @@
 
     /* Read the two limbs input data into a larger modulus and residue */
     TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m2, N2, n2_limbs,
-                endian, MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
+                MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
     rn.p = R2;
     rn.limbs = r2_limbs;
     TEST_EQUAL( MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL,
@@ -232,7 +232,7 @@
 
     /* Init Structures */
     mbedtls_mpi_mod_modulus_init( &m );
-    TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m, N, n_limbs, endian,
+    TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m, N, n_limbs,
                 MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
 
     /* Enforcing p_limbs >= m->limbs */
diff --git a/tests/suites/test_suite_bignum_mod_raw.function b/tests/suites/test_suite_bignum_mod_raw.function
index 0318978..eb1980c 100644
--- a/tests/suites/test_suite_bignum_mod_raw.function
+++ b/tests/suites/test_suite_bignum_mod_raw.function
@@ -49,7 +49,7 @@
 
     mbedtls_mpi_uint init[sizeof( X ) / sizeof( X[0] )];
     memset( init, 0xFF, sizeof( init ) );
-    int ret = mbedtls_mpi_mod_modulus_setup( &m, init, nx, endian,
+    int ret = mbedtls_mpi_mod_modulus_setup( &m, init, nx,
                                              MBEDTLS_MPI_MOD_REP_MONTGOMERY );
     TEST_EQUAL( ret, 0 );
 
@@ -138,7 +138,6 @@
     memset( buff_m, 0xFF, copy_limbs );
     TEST_EQUAL( mbedtls_mpi_mod_modulus_setup(
                         &m, buff_m, copy_limbs,
-                        MBEDTLS_MPI_MOD_EXT_REP_BE,
                         MBEDTLS_MPI_MOD_REP_MONTGOMERY ), 0 );
 
     /* condition is false */
@@ -211,7 +210,6 @@
     memset( buff_m, 0xFF, copy_limbs );
     TEST_EQUAL( mbedtls_mpi_mod_modulus_setup(
                         &m, buff_m, copy_limbs,
-                        MBEDTLS_MPI_MOD_EXT_REP_BE,
                         MBEDTLS_MPI_MOD_REP_MONTGOMERY ), 0 );
 
     ASSERT_ALLOC( X, limbs );
@@ -480,7 +478,7 @@
     TEST_LE_U(a_limbs, n_limbs);
 
     TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m, N, n_limbs,
-                MBEDTLS_MPI_MOD_EXT_REP_BE, MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
+                MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
 
     /* Convert from cannonical into Montgomery representation */
     TEST_EQUAL(0, mbedtls_mpi_mod_raw_to_mont_rep( A, &m ) );
@@ -516,7 +514,7 @@
     TEST_LE_U(a_limbs, n_limbs);
 
     TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m, N, n_limbs,
-                MBEDTLS_MPI_MOD_EXT_REP_BE, MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
+                MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
 
     /* Convert from Montgomery into cannonical representation */
     TEST_EQUAL(0, mbedtls_mpi_mod_raw_from_mont_rep( A, &m ) );