extmod/modussl_mbedtls.c - lite/micropython - Linaro Git Browser

 /*
  * 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> // needed because mp_is_nonblocking_error uses system error codes

 #include "py/runtime.h"
 #include "py/stream.h"

 // mbedtls_time_t
 #include "mbedtls/platform.h"
 #include "mbedtls/net.h"
 #include "mbedtls/ssl.h"
 #include "mbedtls/x509_crt.h"
 #include "mbedtls/pk.h"
 #include "mbedtls/entropy.h"
 #include "mbedtls/ctr_drbg.h"
 #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;
     mbedtls_x509_crt cert;
     mbedtls_pk_context pkey;
 } mp_obj_ssl_socket_t;

 struct ssl_args {
     mp_arg_val_t key;
     mp_arg_val_t cert;
     mp_arg_val_t server_side;
     mp_arg_val_t server_hostname;
 };

 STATIC const mp_obj_type_t ussl_socket_type;

 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) {
         if (mp_is_nonblocking_error(err)) {
             return MBEDTLS_ERR_SSL_WANT_WRITE;
         }
         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) {
         if (mp_is_nonblocking_error(err)) {
             return MBEDTLS_ERR_SSL_WANT_READ;
         }
         return -err;
     } else {
         return out_sz;
     }
 }


 STATIC mp_obj_ssl_socket_t *socket_new(mp_obj_t sock, struct ssl_args *args) {
     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_x509_crt_init(&o->cert);
     mbedtls_pk_init(&o->pkey);
     mbedtls_ctr_drbg_init(&o->ctr_drbg);
     #ifdef MBEDTLS_DEBUG_C
     // Debug level (0-4)
     mbedtls_debug_set_threshold(0);
     #endif

     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,
                     args->server_side.u_bool ? MBEDTLS_SSL_IS_SERVER : 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);
     #ifdef MBEDTLS_DEBUG_C
     mbedtls_ssl_conf_dbg(&o->conf, mbedtls_debug, NULL);
     #endif

     ret = mbedtls_ssl_setup(&o->ssl, &o->conf);
     if (ret != 0) {
         assert(0);
     }

     if (args->server_hostname.u_obj != mp_const_none) {
         const char *sni = mp_obj_str_get_str(args->server_hostname.u_obj);
         ret = mbedtls_ssl_set_hostname(&o->ssl, sni);
         if (ret != 0) {
             assert(0);
         }
     }

     o->sock = sock;
     mbedtls_ssl_set_bio(&o->ssl, &o->sock, _mbedtls_ssl_send, _mbedtls_ssl_recv, NULL);

     if (args->key.u_obj != MP_OBJ_NULL) {
         size_t key_len;
         const byte *key = (const byte*)mp_obj_str_get_data(args->key.u_obj, &key_len);
         // len should include terminating null
         ret = mbedtls_pk_parse_key(&o->pkey, key, key_len + 1, NULL, 0);
         assert(ret == 0);

         size_t cert_len;
         const byte *cert = (const byte*)mp_obj_str_get_data(args->cert.u_obj, &cert_len);
         // len should include terminating null
         ret = mbedtls_x509_crt_parse(&o->cert, cert, cert_len + 1);
         assert(ret == 0);

         ret = mbedtls_ssl_conf_own_cert(&o->conf, &o->cert, &o->pkey);
         assert(ret == 0);
     }

     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);
             mp_raise_OSError(MP_EIO);
         }
     }

     return o;
 }

 STATIC mp_obj_t mod_ssl_getpeercert(mp_obj_t o_in, mp_obj_t binary_form) {
     mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(o_in);
     if (!mp_obj_is_true(binary_form)) {
         mp_raise_NotImplementedError(NULL);
     }
     const mbedtls_x509_crt* peer_cert = mbedtls_ssl_get_peer_cert(&o->ssl);
     return mp_obj_new_bytes(peer_cert->raw.p, peer_cert->raw.len);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_ssl_getpeercert_obj, mod_ssl_getpeercert);

 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 == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY) {
         // end of stream
         return 0;
     }
     if (ret >= 0) {
         return ret;
     }
     if (ret == MBEDTLS_ERR_SSL_WANT_READ) {
         ret = MP_EWOULDBLOCK;
     }
     *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;
     }
     if (ret == MBEDTLS_ERR_SSL_WANT_WRITE) {
         ret = MP_EWOULDBLOCK;
     }
     *errcode = ret;
     return MP_STREAM_ERROR;
 }

 STATIC mp_obj_t socket_setblocking(mp_obj_t self_in, mp_obj_t flag_in) {
     mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(self_in);
     mp_obj_t sock = o->sock;
     mp_obj_t dest[3];
     mp_load_method(sock, MP_QSTR_setblocking, dest);
     dest[2] = flag_in;
     return mp_call_method_n_kw(1, 0, dest);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(socket_setblocking_obj, socket_setblocking);

 STATIC mp_obj_t socket_close(mp_obj_t self_in) {
     mp_obj_ssl_socket_t *self = MP_OBJ_TO_PTR(self_in);

     mbedtls_pk_free(&self->pkey);
     mbedtls_x509_crt_free(&self->cert);
     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);

     return mp_stream_close(self->sock);
 }
 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_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_setblocking), MP_ROM_PTR(&socket_setblocking_obj) },
     { MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&socket_close_obj) },
     { MP_ROM_QSTR(MP_QSTR_getpeercert), MP_ROM_PTR(&mod_ssl_getpeercert_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_key, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
         { MP_QSTR_cert, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
         { MP_QSTR_server_side, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
         { MP_QSTR_server_hostname, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
     };

     // TODO: Check that sock implements stream protocol
     mp_obj_t sock = pos_args[0];

     struct ssl_args 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));
 }
 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
	/*
	* 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> // needed because mp_is_nonblocking_error uses system error codes

	#include "py/runtime.h"
	#include "py/stream.h"

	// mbedtls_time_t
	#include "mbedtls/platform.h"
	#include "mbedtls/net.h"
	#include "mbedtls/ssl.h"
	#include "mbedtls/x509_crt.h"
	#include "mbedtls/pk.h"
	#include "mbedtls/entropy.h"
	#include "mbedtls/ctr_drbg.h"
	#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;
	mbedtls_x509_crt cert;
	mbedtls_pk_context pkey;
	} mp_obj_ssl_socket_t;

	struct ssl_args {
	mp_arg_val_t key;
	mp_arg_val_t cert;
	mp_arg_val_t server_side;
	mp_arg_val_t server_hostname;
	};

	STATIC const mp_obj_type_t ussl_socket_type;

	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) {
	if (mp_is_nonblocking_error(err)) {
	return MBEDTLS_ERR_SSL_WANT_WRITE;
	}
	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) {
	if (mp_is_nonblocking_error(err)) {
	return MBEDTLS_ERR_SSL_WANT_READ;
	}
	return -err;
	} else {
	return out_sz;
	}
	}


	STATIC mp_obj_ssl_socket_t socket_new(mp_obj_t sock, struct ssl_args args) {
	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_x509_crt_init(&o->cert);
	mbedtls_pk_init(&o->pkey);
	mbedtls_ctr_drbg_init(&o->ctr_drbg);
	#ifdef MBEDTLS_DEBUG_C
	// Debug level (0-4)
	mbedtls_debug_set_threshold(0);
	#endif

	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,
	args->server_side.u_bool ? MBEDTLS_SSL_IS_SERVER : 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);
	#ifdef MBEDTLS_DEBUG_C
	mbedtls_ssl_conf_dbg(&o->conf, mbedtls_debug, NULL);
	#endif

	ret = mbedtls_ssl_setup(&o->ssl, &o->conf);
	if (ret != 0) {
	assert(0);
	}

	if (args->server_hostname.u_obj != mp_const_none) {
	const char *sni = mp_obj_str_get_str(args->server_hostname.u_obj);
	ret = mbedtls_ssl_set_hostname(&o->ssl, sni);
	if (ret != 0) {
	assert(0);
	}
	}

	o->sock = sock;
	mbedtls_ssl_set_bio(&o->ssl, &o->sock, _mbedtls_ssl_send, _mbedtls_ssl_recv, NULL);

	if (args->key.u_obj != MP_OBJ_NULL) {
	size_t key_len;
	const byte key = (const byte)mp_obj_str_get_data(args->key.u_obj, &key_len);
	// len should include terminating null
	ret = mbedtls_pk_parse_key(&o->pkey, key, key_len + 1, NULL, 0);
	assert(ret == 0);

	size_t cert_len;
	const byte cert = (const byte)mp_obj_str_get_data(args->cert.u_obj, &cert_len);
	// len should include terminating null
	ret = mbedtls_x509_crt_parse(&o->cert, cert, cert_len + 1);
	assert(ret == 0);

	ret = mbedtls_ssl_conf_own_cert(&o->conf, &o->cert, &o->pkey);
	assert(ret == 0);
	}

	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);
	mp_raise_OSError(MP_EIO);
	}
	}

	return o;
	}

	STATIC mp_obj_t mod_ssl_getpeercert(mp_obj_t o_in, mp_obj_t binary_form) {
	mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(o_in);
	if (!mp_obj_is_true(binary_form)) {
	mp_raise_NotImplementedError(NULL);
	}
	const mbedtls_x509_crt* peer_cert = mbedtls_ssl_get_peer_cert(&o->ssl);
	return mp_obj_new_bytes(peer_cert->raw.p, peer_cert->raw.len);
	}
	STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_ssl_getpeercert_obj, mod_ssl_getpeercert);

	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 == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY) {
	// end of stream
	return 0;
	}
	if (ret >= 0) {
	return ret;
	}
	if (ret == MBEDTLS_ERR_SSL_WANT_READ) {
	ret = MP_EWOULDBLOCK;
	}
	*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;
	}
	if (ret == MBEDTLS_ERR_SSL_WANT_WRITE) {
	ret = MP_EWOULDBLOCK;
	}
	*errcode = ret;
	return MP_STREAM_ERROR;
	}

	STATIC mp_obj_t socket_setblocking(mp_obj_t self_in, mp_obj_t flag_in) {
	mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(self_in);
	mp_obj_t sock = o->sock;
	mp_obj_t dest[3];
	mp_load_method(sock, MP_QSTR_setblocking, dest);
	dest[2] = flag_in;
	return mp_call_method_n_kw(1, 0, dest);
	}
	STATIC MP_DEFINE_CONST_FUN_OBJ_2(socket_setblocking_obj, socket_setblocking);

	STATIC mp_obj_t socket_close(mp_obj_t self_in) {
	mp_obj_ssl_socket_t *self = MP_OBJ_TO_PTR(self_in);

	mbedtls_pk_free(&self->pkey);
	mbedtls_x509_crt_free(&self->cert);
	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);

	return mp_stream_close(self->sock);
	}
	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_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_setblocking), MP_ROM_PTR(&socket_setblocking_obj) },
	{ MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&socket_close_obj) },
	{ MP_ROM_QSTR(MP_QSTR_getpeercert), MP_ROM_PTR(&mod_ssl_getpeercert_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_key, MP_ARG_KW_ONLY \| MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
	{ MP_QSTR_cert, MP_ARG_KW_ONLY \| MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
	{ MP_QSTR_server_side, MP_ARG_KW_ONLY \| MP_ARG_BOOL, {.u_bool = false} },
	{ MP_QSTR_server_hostname, MP_ARG_KW_ONLY \| MP_ARG_OBJ, {.u_obj = mp_const_none} },
	};

	// TODO: Check that sock implements stream protocol
	mp_obj_t sock = pos_args[0];

	struct ssl_args 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));
	}
	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