diff --git a/tests/suites/test_suite_asn1parse.function b/tests/suites/test_suite_asn1parse.function
index abcd1dbc7..535274b74 100644
--- a/tests/suites/test_suite_asn1parse.function
+++ b/tests/suites/test_suite_asn1parse.function
@@ -417,7 +417,7 @@ void get_integer( const data_t *input,
     }
 
 #if defined(MBEDTLS_BIGNUM_C)
-    ret = mbedtls_mpi_read_string( &expected_mpi, 16, expected_hex );
+    ret = mbedtls_test_read_mpi( &expected_mpi, 16, expected_hex );
     TEST_ASSERT( ret == 0 || ret == MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
     if( ret == MBEDTLS_ERR_MPI_BAD_INPUT_DATA )
     {
diff --git a/tests/suites/test_suite_debug.function b/tests/suites/test_suite_debug.function
index fda693987..197a7ef31 100644
--- a/tests/suites/test_suite_debug.function
+++ b/tests/suites/test_suite_debug.function
@@ -179,9 +179,7 @@ void mbedtls_debug_print_mpi( int radix, char * value, char * file, int line,
 
     TEST_ASSERT( mbedtls_ssl_setup( &ssl, &conf ) == 0 );
 
-    /* If value is empty, keep val->n == 0. */
-    if( value[0] != 0 )
-        TEST_ASSERT( mbedtls_mpi_read_string( &val, radix, value ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &val, radix, value ) == 0 );
 
     mbedtls_ssl_conf_dbg( &conf, string_debug, &buffer);
 
diff --git a/tests/suites/test_suite_dhm.function b/tests/suites/test_suite_dhm.function
index 5286bc7b8..bc4301665 100644
--- a/tests/suites/test_suite_dhm.function
+++ b/tests/suites/test_suite_dhm.function
@@ -116,8 +116,8 @@ void dhm_do_dhm( int radix_P, char *input_P, int x_size,
     /*
      * Set params
      */
-    TEST_ASSERT( mbedtls_mpi_read_string( &ctx_srv.P, radix_P, input_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &ctx_srv.G, radix_G, input_G ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &ctx_srv.P, radix_P, input_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &ctx_srv.G, radix_G, input_G ) == 0 );
     pub_cli_len = mbedtls_mpi_size( &ctx_srv.P );
     TEST_ASSERT( check_get_value( &ctx_srv, MBEDTLS_DHM_PARAM_P, &ctx_srv.P ) );
     TEST_ASSERT( check_get_value( &ctx_srv, MBEDTLS_DHM_PARAM_G, &ctx_srv.G ) );
@@ -239,7 +239,7 @@ void dhm_make_public( int P_bytes, int radix_G, char *input_G, int result )
     TEST_ASSERT( mbedtls_mpi_shift_l( &P, ( P_bytes * 8 ) - 1 ) == 0 );
     TEST_ASSERT( mbedtls_mpi_set_bit( &P, 0, 1 ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &G, radix_G, input_G ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &G, radix_G, input_G ) == 0 );
 
     TEST_ASSERT( mbedtls_dhm_set_group( &ctx, &P, &G ) == 0 );
     TEST_ASSERT( mbedtls_dhm_make_public( &ctx, (int) mbedtls_mpi_size( &P ),
@@ -263,8 +263,8 @@ void dhm_file( char * filename, char * p, char * g, int len )
     mbedtls_dhm_init( &ctx );
     mbedtls_mpi_init( &P ); mbedtls_mpi_init( &G );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P, 16, p ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &G, 16, g ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P, 16, p ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &G, 16, g ) == 0 );
 
     TEST_ASSERT( mbedtls_dhm_parse_dhmfile( &ctx, filename ) == 0 );
 
diff --git a/tests/suites/test_suite_ecdh.function b/tests/suites/test_suite_ecdh.function
index 94030d89d..6893bcfa4 100644
--- a/tests/suites/test_suite_ecdh.function
+++ b/tests/suites/test_suite_ecdh.function
@@ -157,21 +157,21 @@ void ecdh_primitive_testvec( int id, data_t * rnd_buf_A, char * xA_str,
                                           mbedtls_test_rnd_buffer_rand,
                                           &rnd_info_A ) == 0 );
     TEST_ASSERT( ! mbedtls_ecp_is_zero( &qA ) );
-    TEST_ASSERT( mbedtls_mpi_read_string( &check, 16, xA_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &check, 16, xA_str ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &qA.X, &check ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &check, 16, yA_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &check, 16, yA_str ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &qA.Y, &check ) == 0 );
 
     TEST_ASSERT( mbedtls_ecdh_gen_public( &grp, &dB, &qB,
                                           mbedtls_test_rnd_buffer_rand,
                                           &rnd_info_B ) == 0 );
     TEST_ASSERT( ! mbedtls_ecp_is_zero( &qB ) );
-    TEST_ASSERT( mbedtls_mpi_read_string( &check, 16, xB_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &check, 16, xB_str ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &qB.X, &check ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &check, 16, yB_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &check, 16, yB_str ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &qB.Y, &check ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &check, 16, z_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &check, 16, z_str ) == 0 );
     TEST_ASSERT( mbedtls_ecdh_compute_shared( &grp, &zA, &qB, &dA,
                                               &mbedtls_test_rnd_pseudo_rand,
                                               &rnd_info ) == 0 );
diff --git a/tests/suites/test_suite_ecdsa.function b/tests/suites/test_suite_ecdsa.function
index 354f17842..880376294 100644
--- a/tests/suites/test_suite_ecdsa.function
+++ b/tests/suites/test_suite_ecdsa.function
@@ -92,9 +92,9 @@ void ecdsa_prim_test_vectors( int id, char * d_str, char * xQ_str,
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
     TEST_ASSERT( mbedtls_ecp_point_read_string( &Q, 16, xQ_str, yQ_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &d, 16, d_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &r_check, 16, r_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &s_check, 16, s_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &d, 16, d_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &r_check, 16, r_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &s_check, 16, s_str ) == 0 );
     rnd_info.fallback_f_rng = mbedtls_test_rnd_std_rand;
     rnd_info.fallback_p_rng = NULL;
     rnd_info.buf = rnd_buf->x;
@@ -157,9 +157,9 @@ void ecdsa_det_test_vectors( int id, char * d_str, int md_alg, char * msg,
     memset( hash, 0, sizeof( hash ) );
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &d, 16, d_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &r_check, 16, r_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &s_check, 16, s_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &d, 16, d_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &r_check, 16, r_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &s_check, 16, s_str ) == 0 );
 
     md_info = mbedtls_md_info_from_type( md_alg );
     TEST_ASSERT( md_info != NULL );
@@ -388,7 +388,7 @@ void ecdsa_write_restart( int id, char *d_str, int md_alg,
     memset( sig, 0, sizeof( sig ) );
 
     TEST_ASSERT( mbedtls_ecp_group_load( &ctx.grp, id ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &ctx.d, 16, d_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &ctx.d, 16, d_str ) == 0 );
 
     md_info = mbedtls_md_info_from_type( md_alg );
     TEST_ASSERT( md_info != NULL );
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index d795fe214..2afc35534 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -82,9 +82,9 @@ void ecp_check_pub( int grp_id, char * x_hex, char * y_hex, char * z_hex,
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, grp_id ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P.X, 16, x_hex ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &P.Y, 16, y_hex ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &P.Z, 16, z_hex ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P.X, 16, x_hex ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P.Y, 16, y_hex ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P.Z, 16, z_hex ) == 0 );
 
     TEST_ASSERT( mbedtls_ecp_check_pubkey( &grp, &P ) == ret );
 
@@ -135,13 +135,13 @@ void ecp_test_vect_restart( int id,
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &dA, 16, dA_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &xA, 16, xA_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &yA, 16, yA_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &dA, 16, dA_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &xA, 16, xA_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &yA, 16, yA_str ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &dB, 16, dB_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &xZ, 16, xZ_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &yZ, 16, yZ_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &dB, 16, dB_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &xZ, 16, xZ_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &yZ, 16, yZ_str ) == 0 );
 
     mbedtls_ecp_set_max_ops( (unsigned) max_ops );
 
@@ -222,13 +222,13 @@ void ecp_muladd_restart( int id, char *xR_str, char *yR_str,
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &u1, 16, u1_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &u2, 16, u2_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &xR, 16, xR_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &yR, 16, yR_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &u1, 16, u1_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &u2, 16, u2_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &xR, 16, xR_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &yR, 16, yR_str ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q.X, 16, xQ_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q.Y, 16, yQ_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q.X, 16, xQ_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q.Y, 16, yQ_str ) == 0 );
     TEST_ASSERT( mbedtls_mpi_lset( &Q.Z, 1 ) == 0 );
 
     mbedtls_ecp_set_max_ops( (unsigned) max_ops );
@@ -285,14 +285,14 @@ void ecp_test_vect( int id, char * dA_str, char * xA_str, char * yA_str,
 
     TEST_ASSERT( mbedtls_ecp_check_pubkey( &grp, &grp.G ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &dA, 16, dA_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &xA, 16, xA_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &yA, 16, yA_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &dB, 16, dB_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &xB, 16, xB_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &yB, 16, yB_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &xZ, 16, xZ_str ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &yZ, 16, yZ_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &dA, 16, dA_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &xA, 16, xA_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &yA, 16, yA_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &dB, 16, dB_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &xB, 16, xB_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &yB, 16, yB_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &xZ, 16, xZ_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &yZ, 16, yZ_str ) == 0 );
 
     TEST_ASSERT( mbedtls_ecp_mul( &grp, &R, &dA, &grp.G,
                           &mbedtls_test_rnd_pseudo_rand, &rnd_info ) == 0 );
@@ -342,11 +342,11 @@ void ecp_test_vec_x( int id, char * dA_hex, char * xA_hex, char * dB_hex,
 
     TEST_ASSERT( mbedtls_ecp_check_pubkey( &grp, &grp.G ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &dA, 16, dA_hex ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &dB, 16, dB_hex ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &xA, 16, xA_hex ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &xB, 16, xB_hex ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &xS, 16, xS_hex ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &dA, 16, dA_hex ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &dB, 16, dB_hex ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &xA, 16, xA_hex ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &xB, 16, xB_hex ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &xS, 16, xS_hex ) == 0 );
 
     TEST_ASSERT( mbedtls_ecp_mul( &grp, &R, &dA, &grp.G,
                           &mbedtls_test_rnd_pseudo_rand, &rnd_info ) == 0 );
@@ -508,7 +508,7 @@ void ecp_fast_mod( int id, char * N_str )
     mbedtls_mpi_init( &N ); mbedtls_mpi_init( &R );
     mbedtls_ecp_group_init( &grp );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, 16, N_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, 16, N_str ) == 0 );
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
     TEST_ASSERT( grp.modp != NULL );
 
@@ -547,9 +547,9 @@ void ecp_write_binary( int id, char * x, char * y, char * z, int format,
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P.X, 16, x ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &P.Y, 16, y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &P.Z, 16, z ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P.X, 16, x ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P.Y, 16, y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P.Z, 16, z ) == 0 );
 
     TEST_ASSERT( mbedtls_ecp_point_write_binary( &grp, &P, format,
                                    &olen, buf, blen ) == ret );
@@ -579,9 +579,9 @@ void ecp_read_binary( int id, data_t * buf, char * x, char * y, char * z,
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, 16, x ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, 16, y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Z, 16, z ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, 16, x ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, 16, y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Z, 16, z ) == 0 );
 
     TEST_ASSERT( mbedtls_ecp_point_read_binary( &grp, &P, buf->x, buf->len ) == ret );
 
@@ -623,9 +623,9 @@ void mbedtls_ecp_tls_read_point( int id, data_t * buf, char * x, char * y,
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, 16, x ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, 16, y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Z, 16, z ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, 16, x ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, 16, y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Z, 16, z ) == 0 );
 
     TEST_ASSERT( mbedtls_ecp_tls_read_point( &grp, &P, &vbuf, buf->len ) == ret );
 
@@ -760,7 +760,7 @@ void mbedtls_ecp_check_privkey( int id, char * key_hex, int ret )
     mbedtls_mpi_init( &d );
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &d, 16, key_hex ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &d, 16, key_hex ) == 0 );
 
     TEST_ASSERT( mbedtls_ecp_check_privkey( &grp, &d ) == ret );
 
@@ -789,7 +789,7 @@ void mbedtls_ecp_check_pub_priv( int id_pub, char * Qx_pub, char * Qy_pub,
     if( id != MBEDTLS_ECP_DP_NONE )
         TEST_ASSERT( mbedtls_ecp_group_load( &prv.grp, id ) == 0 );
     TEST_ASSERT( mbedtls_ecp_point_read_string( &prv.Q, 16, Qx, Qy ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &prv.d, 16, d ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &prv.d, 16, d ) == 0 );
 
     TEST_ASSERT( mbedtls_ecp_check_pub_priv( &pub, &prv,
                           &mbedtls_test_rnd_pseudo_rand, &rnd_info ) == ret );
diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index eb918b31e..eaede01b4 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -214,7 +214,7 @@ void mbedtls_mpi_write_binary( int radix_X, char * input_X,
 
     mbedtls_mpi_init( &X );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
 
     buflen = mbedtls_mpi_size( &X );
     if( buflen > (size_t) output_size )
@@ -246,7 +246,7 @@ void mbedtls_mpi_write_binary_le( int radix_X, char * input_X,
 
     mbedtls_mpi_init( &X );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
 
     buflen = mbedtls_mpi_size( &X );
     if( buflen > (size_t) output_size )
@@ -310,7 +310,7 @@ void mbedtls_mpi_write_file( int radix_X, char * input_X, int output_radix,
 
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
 
     file_out = fopen( output_file, "w" );
     TEST_ASSERT( file_out != NULL );
@@ -336,7 +336,7 @@ void mbedtls_mpi_get_bit( int radix_X, char * input_X, int pos, int val )
 {
     mbedtls_mpi X;
     mbedtls_mpi_init( &X );
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_get_bit( &X, pos ) == val );
 
 exit:
@@ -351,8 +351,8 @@ void mbedtls_mpi_set_bit( int radix_X, char * input_X, int pos, int val,
     mbedtls_mpi X, Y;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, output_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, output_Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_set_bit( &X, pos, val ) == result );
 
     if( result == 0 )
@@ -371,7 +371,7 @@ void mbedtls_mpi_lsb( int radix_X, char * input_X, int nr_bits )
     mbedtls_mpi X;
     mbedtls_mpi_init( &X );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_lsb( &X ) == (size_t) nr_bits );
 
 exit:
@@ -385,7 +385,7 @@ void mbedtls_mpi_bitlen( int radix_X, char * input_X, int nr_bits )
     mbedtls_mpi X;
     mbedtls_mpi_init( &X );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_bitlen( &X ) == (size_t) nr_bits );
 
 exit:
@@ -400,9 +400,9 @@ void mbedtls_mpi_gcd( int radix_X, char * input_X, int radix_Y,
     mbedtls_mpi A, X, Y, Z;
     mbedtls_mpi_init( &A ); mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_gcd( &Z, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
@@ -432,8 +432,8 @@ void mbedtls_mpi_cmp_mpi( int radix_X, char * input_X, int radix_Y,
     mbedtls_mpi X, Y;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &Y ) == input_A );
 
 exit:
@@ -451,8 +451,8 @@ void mbedtls_mpi_lt_mpi_ct( int size_X, char * input_X,
     mbedtls_mpi X, Y;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, 16, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, 16, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, 16, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, 16, input_Y ) == 0 );
 
     TEST_ASSERT( mbedtls_mpi_grow( &X, size_X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_grow( &Y, size_Y ) == 0 );
@@ -473,8 +473,8 @@ void mbedtls_mpi_cmp_abs( int radix_X, char * input_X, int radix_Y,
     mbedtls_mpi X, Y;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_abs( &X, &Y ) == input_A );
 
 exit:
@@ -559,9 +559,9 @@ void mbedtls_mpi_safe_cond_assign( int x_sign, char * x_str, int y_sign,
     mbedtls_mpi X, Y, XX;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &XX );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, 16, x_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, 16, x_str ) == 0 );
     X.s = x_sign;
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, 16, y_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, 16, y_str ) == 0 );
     Y.s = y_sign;
     TEST_ASSERT( mbedtls_mpi_copy( &XX, &X ) == 0 );
 
@@ -585,9 +585,9 @@ void mbedtls_mpi_safe_cond_swap( int x_sign, char * x_str, int y_sign,
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y );
     mbedtls_mpi_init( &XX ); mbedtls_mpi_init( &YY );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, 16, x_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, 16, x_str ) == 0 );
     X.s = x_sign;
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, 16, y_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, 16, y_str ) == 0 );
     Y.s = y_sign;
 
     TEST_ASSERT( mbedtls_mpi_copy( &XX, &X ) == 0 );
@@ -673,16 +673,16 @@ void mbedtls_mpi_add_mpi( int radix_X, char * input_X, int radix_Y,
     mbedtls_mpi X, Y, Z, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_add_mpi( &Z, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
     /* result == first operand */
     TEST_ASSERT( mbedtls_mpi_add_mpi( &X, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
 
     /* result == second operand */
     TEST_ASSERT( mbedtls_mpi_add_mpi( &Y, &X, &Y ) == 0 );
@@ -700,17 +700,17 @@ void mbedtls_mpi_add_mpi_inplace( int radix_X, char * input_X, int radix_A,
     mbedtls_mpi X, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_sub_abs( &X, &X, &X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_int( &X, 0 ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_add_abs( &X, &X, &X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_add_mpi( &X, &X, &X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
 
@@ -727,16 +727,16 @@ void mbedtls_mpi_add_abs( int radix_X, char * input_X, int radix_Y,
     mbedtls_mpi X, Y, Z, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_add_abs( &Z, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
     /* result == first operand */
     TEST_ASSERT( mbedtls_mpi_add_abs( &X, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
 
     /* result == second operand */
     TEST_ASSERT( mbedtls_mpi_add_abs( &Y, &X, &Y ) == 0 );
@@ -754,8 +754,8 @@ void mbedtls_mpi_add_int( int radix_X, char * input_X, int input_Y,
     mbedtls_mpi X, Z, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_add_int( &Z, &X, input_Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
@@ -771,16 +771,16 @@ void mbedtls_mpi_sub_mpi( int radix_X, char * input_X, int radix_Y,
     mbedtls_mpi X, Y, Z, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_sub_mpi( &Z, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
     /* result == first operand */
     TEST_ASSERT( mbedtls_mpi_sub_mpi( &X, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
 
     /* result == second operand */
     TEST_ASSERT( mbedtls_mpi_sub_mpi( &Y, &X, &Y ) == 0 );
@@ -800,9 +800,9 @@ void mbedtls_mpi_sub_abs( int radix_X, char * input_X, int radix_Y,
     int res;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
 
     res = mbedtls_mpi_sub_abs( &Z, &X, &Y );
     TEST_ASSERT( res == sub_result );
@@ -813,7 +813,7 @@ void mbedtls_mpi_sub_abs( int radix_X, char * input_X, int radix_Y,
     TEST_ASSERT( mbedtls_mpi_sub_abs( &X, &X, &Y ) == sub_result );
     if( sub_result == 0 )
         TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
 
     /* result == second operand */
     TEST_ASSERT( mbedtls_mpi_sub_abs( &Y, &X, &Y ) == sub_result );
@@ -832,8 +832,8 @@ void mbedtls_mpi_sub_int( int radix_X, char * input_X, int input_Y,
     mbedtls_mpi X, Z, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_sub_int( &Z, &X, input_Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
@@ -849,9 +849,9 @@ void mbedtls_mpi_mul_mpi( int radix_X, char * input_X, int radix_Y,
     mbedtls_mpi X, Y, Z, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_mul_mpi( &Z, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
@@ -868,8 +868,8 @@ void mbedtls_mpi_mul_int( int radix_X, char * input_X, int input_Y,
     mbedtls_mpi X, Z, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_mul_int( &Z, &X, input_Y ) == 0 );
     if( strcmp( result_comparison, "==" ) == 0 )
         TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
@@ -893,10 +893,10 @@ void mbedtls_mpi_div_mpi( int radix_X, char * input_X, int radix_Y,
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &R );
     mbedtls_mpi_init( &A ); mbedtls_mpi_init( &B );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &B, radix_B, input_B ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &B, radix_B, input_B ) == 0 );
     res = mbedtls_mpi_div_mpi( &Q, &R, &X, &Y );
     TEST_ASSERT( res == div_result );
     if( res == 0 )
@@ -921,9 +921,9 @@ void mbedtls_mpi_div_int( int radix_X, char * input_X, int input_Y,
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Q ); mbedtls_mpi_init( &R ); mbedtls_mpi_init( &A );
     mbedtls_mpi_init( &B );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &B, radix_B, input_B ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &B, radix_B, input_B ) == 0 );
     res = mbedtls_mpi_div_int( &Q, &R, &X, input_Y );
     TEST_ASSERT( res == div_result );
     if( res == 0 )
@@ -947,9 +947,9 @@ void mbedtls_mpi_mod_mpi( int radix_X, char * input_X, int radix_Y,
     int res;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     res = mbedtls_mpi_mod_mpi( &X, &X, &Y );
     TEST_ASSERT( res == div_result );
     if( res == 0 )
@@ -971,7 +971,7 @@ void mbedtls_mpi_mod_int( int radix_X, char * input_X, int input_Y,
     mbedtls_mpi_uint r;
     mbedtls_mpi_init( &X );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
     res = mbedtls_mpi_mod_int( &r, &X, input_Y );
     TEST_ASSERT( res == div_result );
     if( res == 0 )
@@ -995,13 +995,13 @@ void mbedtls_mpi_exp_mod( int radix_A, char * input_A, int radix_E,
     mbedtls_mpi_init( &A  ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &N );
     mbedtls_mpi_init( &RR ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &X );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
 
     if( strlen( input_RR ) )
-        TEST_ASSERT( mbedtls_mpi_read_string( &RR, radix_RR, input_RR ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &RR, radix_RR, input_RR ) == 0 );
 
     res = mbedtls_mpi_exp_mod( &Z, &A, &E, &N, &RR );
     TEST_ASSERT( res == div_result );
@@ -1040,7 +1040,7 @@ void mbedtls_mpi_exp_mod_size( int A_bytes, int E_bytes, int N_bytes,
     TEST_ASSERT( mbedtls_mpi_set_bit( &N, 0, 1 ) == 0 );
 
     if( strlen( input_RR ) )
-        TEST_ASSERT( mbedtls_mpi_read_string( &RR, radix_RR, input_RR ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &RR, radix_RR, input_RR ) == 0 );
 
     TEST_ASSERT( mbedtls_mpi_exp_mod( &Z, &A, &E, &N, &RR ) == exp_result );
 
@@ -1059,9 +1059,9 @@ void mbedtls_mpi_inv_mod( int radix_X, char * input_X, int radix_Y,
     int res;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Y, radix_Y, input_Y ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     res = mbedtls_mpi_inv_mod( &Z, &X, &Y );
     TEST_ASSERT( res == div_result );
     if( res == 0 )
@@ -1081,7 +1081,7 @@ void mbedtls_mpi_is_prime( int radix_X, char * input_X, int div_result )
     int res;
     mbedtls_mpi_init( &X );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
     res = mbedtls_mpi_is_prime_ext( &X, 40, mbedtls_test_rnd_std_rand, NULL );
     TEST_ASSERT( res == div_result );
 
@@ -1167,8 +1167,8 @@ void mbedtls_mpi_shift_l( int radix_X, char * input_X, int shift_X,
     mbedtls_mpi X, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_shift_l( &X, shift_X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
 
@@ -1184,8 +1184,8 @@ void mbedtls_mpi_shift_r( int radix_X, char * input_X, int shift_X,
     mbedtls_mpi X, A;
     mbedtls_mpi_init( &X ); mbedtls_mpi_init( &A );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &A, radix_A, input_A ) == 0 );
     TEST_ASSERT( mbedtls_mpi_shift_r( &X, shift_X ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
 
diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index 5ccb072e7..0d4ff08ea 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -403,8 +403,8 @@ void pk_rsa_verify_test_vec( data_t * message_str, int digest, int mod,
     rsa = mbedtls_pk_rsa( pk );
 
     rsa->len = mod / 8;
-    TEST_ASSERT( mbedtls_mpi_read_string( &rsa->N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &rsa->E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &rsa->N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &rsa->E, radix_E, input_E ) == 0 );
 
 
     if( mbedtls_md_info_from_type( digest ) != NULL )
@@ -446,8 +446,8 @@ void pk_rsa_verify_ext_test_vec( data_t * message_str, int digest,
     rsa = mbedtls_pk_rsa( pk );
 
     rsa->len = mod / 8;
-    TEST_ASSERT( mbedtls_mpi_read_string( &rsa->N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &rsa->E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &rsa->N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &rsa->E, radix_E, input_E ) == 0 );
 
 
     if( digest != MBEDTLS_MD_NONE )
@@ -534,7 +534,7 @@ void pk_sign_verify_restart( int pk_type, int grp_id, char *d_str,
 
     TEST_ASSERT( mbedtls_pk_setup( &prv, mbedtls_pk_info_from_type( pk_type ) ) == 0 );
     TEST_ASSERT( mbedtls_ecp_group_load( &mbedtls_pk_ec( prv )->grp, grp_id ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &mbedtls_pk_ec( prv )->d, 16, d_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &mbedtls_pk_ec( prv )->d, 16, d_str ) == 0 );
 
     TEST_ASSERT( mbedtls_pk_setup( &pub, mbedtls_pk_info_from_type( pk_type ) ) == 0 );
     TEST_ASSERT( mbedtls_ecp_group_load( &mbedtls_pk_ec( pub )->grp, grp_id ) == 0 );
@@ -720,8 +720,8 @@ void pk_rsa_encrypt_test_vec( data_t * message, int mod, int radix_N,
     rsa = mbedtls_pk_rsa( pk );
 
     rsa->len = mod / 8;
-    TEST_ASSERT( mbedtls_mpi_read_string( &rsa->N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &rsa->E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &rsa->N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &rsa->E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_pk_encrypt( &pk, message->x, message->len,
                             output, &olen, sizeof( output ),
@@ -759,12 +759,12 @@ void pk_rsa_decrypt_test_vec( data_t * cipher, int mod, int radix_P,
     rsa = mbedtls_pk_rsa( pk );
 
     /* load public key */
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     /* load private key */
-    TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
     TEST_ASSERT( mbedtls_rsa_import( rsa, &N, &P, &Q, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( rsa ) == (size_t) ( mod / 8 ) );
     TEST_ASSERT( mbedtls_rsa_complete( rsa ) == 0 );
diff --git a/tests/suites/test_suite_pkcs1_v15.function b/tests/suites/test_suite_pkcs1_v15.function
index d78ee8895..2089c6251 100644
--- a/tests/suites/test_suite_pkcs1_v15.function
+++ b/tests/suites/test_suite_pkcs1_v15.function
@@ -30,8 +30,8 @@ void pkcs1_rsaes_v15_encrypt( int mod, int radix_N, char * input_N,
                                           MBEDTLS_RSA_PKCS_V15, hash ) == 0 );
     memset( output, 0x00, sizeof( output ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, NULL, NULL, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( ( mod + 7 ) / 8 ) );
     TEST_ASSERT( mbedtls_rsa_check_pubkey( &ctx ) == 0 );
@@ -80,10 +80,10 @@ void pkcs1_rsaes_v15_decrypt( int mod, int radix_P, char * input_P,
     memset( output, 0x00, sizeof( output ) );
     memset( &rnd_info, 0, sizeof( mbedtls_test_rnd_pseudo_info ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, &P, &Q, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( ( mod + 7 ) / 8 ) );
@@ -288,10 +288,10 @@ void pkcs1_rsassa_v15_sign( int mod, int radix_P, char * input_P, int radix_Q,
     memset( hash_result, 0x00, sizeof( hash_result ) );
     memset( output, 0x00, sizeof( output ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, &P, &Q, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( ( mod + 7 ) / 8 ) );
@@ -336,8 +336,8 @@ void pkcs1_rsassa_v15_verify( int mod, int radix_N, char * input_N,
                                           MBEDTLS_RSA_PKCS_V15, hash ) == 0 );
     memset( hash_result, 0x00, sizeof( hash_result ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, NULL, NULL, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( ( mod + 7 ) / 8 ) );
     TEST_ASSERT( mbedtls_rsa_check_pubkey( &ctx ) == 0 );
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index eb96e30eb..bb2df8d93 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -99,10 +99,10 @@ void mbedtls_rsa_pkcs1_sign( data_t * message_str, int padding_mode,
     memset( output, 0x00, sizeof( output ) );
     memset( &rnd_info, 0, sizeof( mbedtls_test_rnd_pseudo_info ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, &P, &Q, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( mod / 8 ) );
@@ -147,8 +147,8 @@ void mbedtls_rsa_pkcs1_verify( data_t * message_str, int padding_mode,
                                           MBEDTLS_MD_NONE ) == 0 );
     memset( hash_result, 0x00, sizeof( hash_result ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, NULL, NULL, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( mod / 8 ) );
     TEST_ASSERT( mbedtls_rsa_check_pubkey( &ctx ) == 0 );
@@ -187,10 +187,10 @@ void rsa_pkcs1_sign_raw( data_t * hash_result,
     memset( output, 0x00, sizeof( output ) );
     memset( &rnd_info, 0, sizeof( mbedtls_test_rnd_pseudo_info ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, &P, &Q, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( mod / 8 ) );
@@ -232,8 +232,8 @@ void rsa_pkcs1_verify_raw( data_t * hash_result,
                                           MBEDTLS_MD_NONE ) == 0 );
     memset( output, 0x00, sizeof( output ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, NULL, NULL, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( mod / 8 ) );
@@ -268,8 +268,8 @@ void mbedtls_rsa_pkcs1_encrypt( data_t * message_str, int padding_mode,
                                           MBEDTLS_MD_NONE ) == 0 );
     memset( output, 0x00, sizeof( output ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, NULL, NULL, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( mod / 8 ) );
@@ -311,8 +311,8 @@ void rsa_pkcs1_encrypt_bad_rng( data_t * message_str, int padding_mode,
                                           MBEDTLS_MD_NONE ) == 0 );
     memset( output, 0x00, sizeof( output ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, NULL, NULL, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( mod / 8 ) );
@@ -361,10 +361,10 @@ void mbedtls_rsa_pkcs1_decrypt( data_t * message_str, int padding_mode,
     memset( &rnd_info, 0, sizeof( mbedtls_test_rnd_pseudo_info ) );
 
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, &P, &Q, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( mod / 8 ) );
@@ -407,8 +407,8 @@ void mbedtls_rsa_public( data_t * message_str, int mod, int radix_N,
     mbedtls_rsa_init( &ctx2 );
     memset( output, 0x00, sizeof( output ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, NULL, NULL, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( mod / 8 ) );
@@ -466,10 +466,10 @@ void mbedtls_rsa_private( data_t * message_str, int mod, int radix_P,
 
     memset( &rnd_info, 0, sizeof( mbedtls_test_rnd_pseudo_info ) );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, &P, &Q, NULL, &E ) == 0 );
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( mod / 8 ) );
@@ -542,11 +542,11 @@ void mbedtls_rsa_check_pubkey( int radix_N, char * input_N, int radix_E,
 
     if( strlen( input_N ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
     }
     if( strlen( input_E ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
     }
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx, &N, NULL, NULL, NULL, &E ) == 0 );
@@ -574,36 +574,36 @@ void mbedtls_rsa_check_privkey( int mod, int radix_P, char * input_P,
     ctx.len = mod / 8;
     if( strlen( input_P ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &ctx.P, radix_P, input_P ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &ctx.P, radix_P, input_P ) == 0 );
     }
     if( strlen( input_Q ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &ctx.Q, radix_Q, input_Q ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &ctx.Q, radix_Q, input_Q ) == 0 );
     }
     if( strlen( input_N ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &ctx.N, radix_N, input_N ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &ctx.N, radix_N, input_N ) == 0 );
     }
     if( strlen( input_E ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &ctx.E, radix_E, input_E ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &ctx.E, radix_E, input_E ) == 0 );
     }
     if( strlen( input_D ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &ctx.D, radix_D, input_D ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &ctx.D, radix_D, input_D ) == 0 );
     }
 #if !defined(MBEDTLS_RSA_NO_CRT)
     if( strlen( input_DP ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &ctx.DP, radix_DP, input_DP ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &ctx.DP, radix_DP, input_DP ) == 0 );
     }
     if( strlen( input_DQ ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &ctx.DQ, radix_DQ, input_DQ ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &ctx.DQ, radix_DQ, input_DQ ) == 0 );
     }
     if( strlen( input_QP ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &ctx.QP, radix_QP, input_QP ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &ctx.QP, radix_QP, input_QP ) == 0 );
     }
 #else
     ((void) radix_DP); ((void) input_DP);
@@ -638,45 +638,45 @@ void rsa_check_pubpriv( int mod, int radix_Npub, char * input_Npub,
 
     if( strlen( input_Npub ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &pub.N, radix_Npub, input_Npub ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &pub.N, radix_Npub, input_Npub ) == 0 );
     }
     if( strlen( input_Epub ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &pub.E, radix_Epub, input_Epub ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &pub.E, radix_Epub, input_Epub ) == 0 );
     }
 
     if( strlen( input_P ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &prv.P, radix_P, input_P ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &prv.P, radix_P, input_P ) == 0 );
     }
     if( strlen( input_Q ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &prv.Q, radix_Q, input_Q ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &prv.Q, radix_Q, input_Q ) == 0 );
     }
     if( strlen( input_N ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &prv.N, radix_N, input_N ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &prv.N, radix_N, input_N ) == 0 );
     }
     if( strlen( input_E ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &prv.E, radix_E, input_E ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &prv.E, radix_E, input_E ) == 0 );
     }
     if( strlen( input_D ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &prv.D, radix_D, input_D ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &prv.D, radix_D, input_D ) == 0 );
     }
 #if !defined(MBEDTLS_RSA_NO_CRT)
     if( strlen( input_DP ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &prv.DP, radix_DP, input_DP ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &prv.DP, radix_DP, input_DP ) == 0 );
     }
     if( strlen( input_DQ ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &prv.DQ, radix_DQ, input_DQ ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &prv.DQ, radix_DQ, input_DQ ) == 0 );
     }
     if( strlen( input_QP ) )
     {
-        TEST_ASSERT( mbedtls_mpi_read_string( &prv.QP, radix_QP, input_QP ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &prv.QP, radix_QP, input_QP ) == 0 );
     }
 #else
     ((void) radix_DP); ((void) input_DP);
@@ -737,11 +737,11 @@ void mbedtls_rsa_deduce_primes( int radix_N, char *input_N,
     mbedtls_mpi_init( &Pp ); mbedtls_mpi_init( &Qp );
     mbedtls_mpi_init( &D ); mbedtls_mpi_init( &E );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &D, radix_D, input_D ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Qp, radix_P, output_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Pp, radix_Q, output_Q ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &D, radix_D, input_D ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Qp, radix_P, output_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Pp, radix_Q, output_Q ) == 0 );
 
     if( corrupt )
         TEST_ASSERT( mbedtls_mpi_add_int( &D, &D, 2 ) == 0 );
@@ -778,10 +778,10 @@ void mbedtls_rsa_deduce_private_exponent( int radix_P, char *input_P,
     mbedtls_mpi_init( &E );
     mbedtls_mpi_init( &R ); mbedtls_mpi_init( &Rp );
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Dp, radix_D, output_D ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &Dp, radix_D, output_D ) == 0 );
 
     if( corrupt )
     {
@@ -864,19 +864,19 @@ void mbedtls_rsa_import( int radix_N, char *input_N,
                                 (const unsigned char *) pers, strlen( pers ) ) == 0 );
 
     if( have_N )
-        TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
 
     if( have_P )
-        TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
 
     if( have_Q )
-        TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
 
     if( have_D )
-        TEST_ASSERT( mbedtls_mpi_read_string( &D, radix_D, input_D ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &D, radix_D, input_D ) == 0 );
 
     if( have_E )
-        TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     if( !successive )
     {
@@ -1008,19 +1008,19 @@ void mbedtls_rsa_export( int radix_N, char *input_N,
     /* Setup RSA context */
 
     if( have_N )
-        TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
 
     if( have_P )
-        TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
 
     if( have_Q )
-        TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
 
     if( have_D )
-        TEST_ASSERT( mbedtls_mpi_read_string( &D, radix_D, input_D ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &D, radix_D, input_D ) == 0 );
 
     if( have_E )
-        TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_import( &ctx,
                                      strlen( input_N ) ? &N : NULL,
@@ -1128,19 +1128,19 @@ void mbedtls_rsa_validate_params( int radix_N, char *input_N,
                                         strlen( pers ) ) == 0 );
 
     if( have_N )
-        TEST_ASSERT( mbedtls_mpi_read_string( &N, radix_N, input_N ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
 
     if( have_P )
-        TEST_ASSERT( mbedtls_mpi_read_string( &P, radix_P, input_P ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &P, radix_P, input_P ) == 0 );
 
     if( have_Q )
-        TEST_ASSERT( mbedtls_mpi_read_string( &Q, radix_Q, input_Q ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &Q, radix_Q, input_Q ) == 0 );
 
     if( have_D )
-        TEST_ASSERT( mbedtls_mpi_read_string( &D, radix_D, input_D ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &D, radix_D, input_D ) == 0 );
 
     if( have_E )
-        TEST_ASSERT( mbedtls_mpi_read_string( &E, radix_E, input_E ) == 0 );
+        TEST_ASSERT( mbedtls_test_read_mpi( &E, radix_E, input_E ) == 0 );
 
     TEST_ASSERT( mbedtls_rsa_validate_params( have_N ? &N : NULL,
                                         have_P ? &P : NULL,
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index c9b7cf9c5..261794c7f 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -248,7 +248,7 @@ void x509_crt_check( char *subject_key_file, char *subject_pwd,
     (void) rsa_alt;
 #endif
 
-    TEST_ASSERT( mbedtls_mpi_read_string( &serial, 10, serial_str ) == 0 );
+    TEST_ASSERT( mbedtls_test_read_mpi( &serial, 10, serial_str ) == 0 );
 
     if( ver != -1 )
         mbedtls_x509write_crt_set_version( &crt, ver );