extmod/modussl_mbedtls: Initial implementation of mbedTLS ussl module.

extmod/modussl_mbedtls.c

+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Linaro Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/mpconfig.h"
+#if MICROPY_PY_USSL && MICROPY_SSL_MBEDTLS
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+#include "py/nlr.h"
+#include "py/runtime.h"
+#include "py/stream.h"
+
+// mbedtls_time_t
+#include "mbedtls/include/mbedtls/platform.h"
+#include "mbedtls/include/mbedtls/net.h"
+#include "mbedtls/include/mbedtls/ssl.h"
+#include "mbedtls/include/mbedtls/entropy.h"
+#include "mbedtls/include/mbedtls/ctr_drbg.h"
+#include "mbedtls/include/mbedtls/debug.h"
+
+typedef struct _mp_obj_ssl_socket_t {
+    mp_obj_base_t base;
+    mp_obj_t sock;
+    mbedtls_entropy_context entropy;
+    mbedtls_ctr_drbg_context ctr_drbg;
+    mbedtls_ssl_context ssl;
+    mbedtls_ssl_config conf;
+    mbedtls_x509_crt cacert;
+} mp_obj_ssl_socket_t;
+
+STATIC const mp_obj_type_t ussl_socket_type;
+
+static void mbedtls_debug(void *ctx, int level, const char *file, int line, const char *str) {
+    printf("DBG:%s:%04d: %s\n", file, line, str);
+}
+
+// TODO: FIXME!
+int null_entropy_func(void *data, unsigned char *output, size_t len) {
+    // enjoy random bytes
+    return 0;
+}
+
+int _mbedtls_ssl_send(void *ctx, const byte *buf, size_t len) {
+    mp_obj_t sock = *(mp_obj_t*)ctx;
+
+    const mp_stream_p_t *sock_stream = mp_get_stream_raise(sock, MP_STREAM_OP_WRITE);
+    int err;
+
+    int out_sz = sock_stream->write(sock, buf, len, &err);
+    if (out_sz == MP_STREAM_ERROR) {
+        return -err;
+    } else {
+        return out_sz;
+    }
+}
+
+int _mbedtls_ssl_recv(void *ctx, byte *buf, size_t len) {
+    mp_obj_t sock = *(mp_obj_t*)ctx;
+
+    const mp_stream_p_t *sock_stream = mp_get_stream_raise(sock, MP_STREAM_OP_READ);
+    int err;
+
+    int out_sz = sock_stream->read(sock, buf, len, &err);
+    if (out_sz == MP_STREAM_ERROR) {
+        return -err;
+    } else {
+        return out_sz;
+    }
+}
+
+
+STATIC mp_obj_ssl_socket_t *socket_new(mp_obj_t sock, bool server_side) {
+    mp_obj_ssl_socket_t *o = m_new_obj(mp_obj_ssl_socket_t);
+    o->base.type = &ussl_socket_type;
+
+    int ret;
+    mbedtls_ssl_init(&o->ssl);
+    mbedtls_ssl_config_init(&o->conf);
+    mbedtls_x509_crt_init(&o->cacert);
+    mbedtls_ctr_drbg_init(&o->ctr_drbg);
+    // Debug level (0-4)
+    mbedtls_debug_set_threshold(0);
+
+    mbedtls_entropy_init(&o->entropy);
+    const byte seed[] = "upy";
+    ret = mbedtls_ctr_drbg_seed(&o->ctr_drbg, null_entropy_func/*mbedtls_entropy_func*/, &o->entropy, seed, sizeof(seed));
+    if (ret != 0) {
+        printf("ret=%d\n", ret);
+        assert(0);
+    }
+
+    ret = mbedtls_ssl_config_defaults(&o->conf,
+                    MBEDTLS_SSL_IS_CLIENT,
+                    MBEDTLS_SSL_TRANSPORT_STREAM,
+                    MBEDTLS_SSL_PRESET_DEFAULT);
+    if (ret != 0) {
+        assert(0);
+    }
+
+    mbedtls_ssl_conf_authmode(&o->conf, MBEDTLS_SSL_VERIFY_NONE);
+    mbedtls_ssl_conf_rng(&o->conf, mbedtls_ctr_drbg_random, &o->ctr_drbg);
+    mbedtls_ssl_conf_dbg(&o->conf, mbedtls_debug, NULL);
+
+    ret = mbedtls_ssl_setup(&o->ssl, &o->conf);
+    if (ret != 0) {
+        assert(0);
+    }
+
+    // delme
+    ret = mbedtls_ssl_set_hostname(&o->ssl, "mbed TLS Server 1");
+    if (ret != 0) {
+        assert(0);
+    }
+
+    o->sock = sock;
+    mbedtls_ssl_set_bio(&o->ssl, &o->sock, _mbedtls_ssl_send, _mbedtls_ssl_recv, NULL);
+
+    if (server_side) {
+        assert(0);
+    } else {
+        while ((ret = mbedtls_ssl_handshake(&o->ssl)) != 0) {
+            if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
+                //assert(0);
+                printf("mbedtls_ssl_handshake error: -%x\n", -ret);
+                nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(EIO)));
+            }
+        }
+    }
+
+    return o;
+}
+
+STATIC void socket_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+    (void)kind;
+    mp_obj_ssl_socket_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_printf(print, "<_SSLSocket %p>", self);
+}
+
+STATIC mp_uint_t socket_read(mp_obj_t o_in, void *buf, mp_uint_t size, int *errcode) {
+    mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(o_in);
+
+    int ret = mbedtls_ssl_read(&o->ssl, buf, size);
+    if (ret >= 0) {
+        return ret;
+    }
+    *errcode = ret;
+    return MP_STREAM_ERROR;
+}
+
+STATIC mp_uint_t socket_write(mp_obj_t o_in, const void *buf, mp_uint_t size, int *errcode) {
+    mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(o_in);
+
+    int ret = mbedtls_ssl_write(&o->ssl, buf, size);
+    if (ret >= 0) {
+        return ret;
+    }
+    *errcode = ret;
+    return MP_STREAM_ERROR;
+}
+
+STATIC mp_obj_t socket_close(mp_obj_t self_in) {
+    mp_obj_ssl_socket_t *self = MP_OBJ_TO_PTR(self_in);
+
+    mbedtls_x509_crt_free(&self->cacert);
+    mbedtls_ssl_free(&self->ssl);
+    mbedtls_ssl_config_free(&self->conf);
+    mbedtls_ctr_drbg_free(&self->ctr_drbg);
+    mbedtls_entropy_free(&self->entropy);
+
+    mp_obj_t dest[2];
+    mp_load_method(self->sock, MP_QSTR_close, dest);
+    return mp_call_method_n_kw(0, 0, dest);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(socket_close_obj, socket_close);
+
+STATIC const mp_rom_map_elem_t ussl_socket_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
+    { MP_ROM_QSTR(MP_QSTR_readall), MP_ROM_PTR(&mp_stream_readall_obj) },
+    { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
+    { MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
+    { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
+    { MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&socket_close_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(ussl_socket_locals_dict, ussl_socket_locals_dict_table);
+
+STATIC const mp_stream_p_t ussl_socket_stream_p = {
+    .read = socket_read,
+    .write = socket_write,
+};
+
+STATIC const mp_obj_type_t ussl_socket_type = {
+    { &mp_type_type },
+    // Save on qstr's, reuse same as for module
+    .name = MP_QSTR_ussl,
+    .print = socket_print,
+    .getiter = NULL,
+    .iternext = NULL,
+    .protocol = &ussl_socket_stream_p,
+    .locals_dict = (void*)&ussl_socket_locals_dict,
+};
+
+STATIC mp_obj_t mod_ssl_wrap_socket(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    // TODO: Implement more args
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_server_side, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
+    };
+
+    // TODO: Check that sock implements stream protocol
+    mp_obj_t sock = pos_args[0];
+
+    struct {
+        mp_arg_val_t server_side;
+    } args;
+    mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args,
+        MP_ARRAY_SIZE(allowed_args), allowed_args, (mp_arg_val_t*)&args);
+
+    return MP_OBJ_FROM_PTR(socket_new(sock, args.server_side.u_bool));
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(mod_ssl_wrap_socket_obj, 1, mod_ssl_wrap_socket);
+
+STATIC const mp_rom_map_elem_t mp_module_ssl_globals_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_ussl) },
+    { MP_ROM_QSTR(MP_QSTR_wrap_socket), MP_ROM_PTR(&mod_ssl_wrap_socket_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(mp_module_ssl_globals, mp_module_ssl_globals_table);
+
+const mp_obj_module_t mp_module_ussl = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t*)&mp_module_ssl_globals,
+};
+
+#endif // MICROPY_PY_USSL