1 | /**
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2 | * @file
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3 | * Application layered TCP/TLS connection API (to be used from TCPIP thread)
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4 | *
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5 | * This file provides a TLS layer using mbedTLS
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6 | */
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7 |
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8 | /*
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9 | * Copyright (c) 2017 Simon Goldschmidt
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10 | * All rights reserved.
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11 | *
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12 | * Redistribution and use in source and binary forms, with or without modification,
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13 | * are permitted provided that the following conditions are met:
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14 | *
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15 | * 1. Redistributions of source code must retain the above copyright notice,
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16 | * this list of conditions and the following disclaimer.
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17 | * 2. Redistributions in binary form must reproduce the above copyright notice,
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18 | * this list of conditions and the following disclaimer in the documentation
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19 | * and/or other materials provided with the distribution.
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20 | * 3. The name of the author may not be used to endorse or promote products
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21 | * derived from this software without specific prior written permission.
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22 | *
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23 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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24 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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25 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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26 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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27 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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28 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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29 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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30 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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31 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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32 | * OF SUCH DAMAGE.
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33 | *
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34 | * This file is part of the lwIP TCP/IP stack.
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35 | *
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36 | * Author: Simon Goldschmidt <goldsimon@gmx.de>
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37 | *
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38 | * Watch out:
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39 | * - 'sent' is always called with len==0 to the upper layer. This is because keeping
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40 | * track of the ratio of application data and TLS overhead would be too much.
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41 | *
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42 | * Mandatory security-related configuration:
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43 | * - define ALTCP_MBEDTLS_RNG_FN to mbedtls_entropy_func to use the standard mbedTLS
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44 | * entropy and ensure to add at least one strong entropy source to your mbedtls port
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45 | * (implement mbedtls_platform_entropy_poll or mbedtls_hardware_poll providing strong
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46 | * entropy)
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47 | * - define ALTCP_MBEDTLS_ENTROPY_PTR and ALTCP_MBEDTLS_ENTROPY_LEN to something providing
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48 | * GOOD custom entropy
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49 | *
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50 | * Missing things / @todo:
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51 | * - some unhandled/untested things migh be caught by LWIP_ASSERTs...
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52 | */
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53 |
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54 | #include "lwip/opt.h"
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55 |
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56 | #if LWIP_ALTCP /* don't build if not configured for use in lwipopts.h */
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57 |
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58 | #include "lwip/apps/altcp_tls_mbedtls_opts.h"
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59 |
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60 | #if LWIP_ALTCP_TLS && LWIP_ALTCP_TLS_MBEDTLS
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61 |
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62 | #include "lwip/altcp.h"
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63 | #include "lwip/altcp_tls.h"
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64 | #include "lwip/priv/altcp_priv.h"
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65 |
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66 | #include "altcp_tls_mbedtls_structs.h"
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67 | #include "altcp_tls_mbedtls_mem.h"
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68 |
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69 | /* @todo: which includes are really needed? */
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70 | #include "mbedtls/entropy.h"
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71 | #include "mbedtls/ctr_drbg.h"
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72 | #include "mbedtls/certs.h"
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73 | #include "mbedtls/x509.h"
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74 | #include "mbedtls/ssl.h"
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75 | #include "mbedtls/net.h"
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76 | #include "mbedtls/error.h"
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77 | #include "mbedtls/debug.h"
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78 | #include "mbedtls/platform.h"
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79 | #include "mbedtls/memory_buffer_alloc.h"
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80 | #include "mbedtls/ssl_cache.h"
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81 |
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82 | #include "mbedtls/ssl_internal.h" /* to call mbedtls_flush_output after ERR_MEM */
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83 |
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84 | #include <string.h>
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85 |
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86 | #ifndef ALTCP_MBEDTLS_ENTROPY_PTR
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87 | #define ALTCP_MBEDTLS_ENTROPY_PTR NULL
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88 | #endif
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89 | #ifndef ALTCP_MBEDTLS_ENTROPY_LEN
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90 | #define ALTCP_MBEDTLS_ENTROPY_LEN 0
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91 | #endif
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92 |
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93 | /* Variable prototype, the actual declaration is at the end of this file
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94 | since it contains pointers to static functions declared here */
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95 | extern const struct altcp_functions altcp_mbedtls_functions;
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96 |
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97 | /** Our global mbedTLS configuration (server-specific, not connection-specific) */
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98 | struct altcp_tls_config {
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99 | mbedtls_ssl_config conf;
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100 | mbedtls_entropy_context entropy;
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101 | mbedtls_ctr_drbg_context ctr_drbg;
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102 | mbedtls_x509_crt *cert;
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103 | mbedtls_pk_context *pkey;
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104 | mbedtls_x509_crt *ca;
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105 | #if defined(MBEDTLS_SSL_CACHE_C) && ALTCP_MBEDTLS_SESSION_CACHE_TIMEOUT_SECONDS
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106 | /** Inter-connection cache for fast connection startup */
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107 | struct mbedtls_ssl_cache_context cache;
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108 | #endif
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109 | };
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110 |
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111 | static err_t altcp_mbedtls_lower_recv(void *arg, struct altcp_pcb *inner_conn, struct pbuf *p, err_t err);
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112 | static err_t altcp_mbedtls_setup(void *conf, struct altcp_pcb *conn, struct altcp_pcb *inner_conn);
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113 | static err_t altcp_mbedtls_lower_recv_process(struct altcp_pcb *conn, altcp_mbedtls_state_t *state);
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114 | static err_t altcp_mbedtls_handle_rx_appldata(struct altcp_pcb *conn, altcp_mbedtls_state_t *state);
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115 | static int altcp_mbedtls_bio_send(void *ctx, const unsigned char *dataptr, size_t size);
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116 |
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117 |
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118 | /* callback functions from inner/lower connection: */
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119 |
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120 | /** Accept callback from lower connection (i.e. TCP)
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121 | * Allocate one of our structures, assign it to the new connection's 'state' and
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122 | * call the new connection's 'accepted' callback. If that succeeds, we wait
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123 | * to receive connection setup handshake bytes from the client.
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124 | */
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125 | static err_t
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126 | altcp_mbedtls_lower_accept(void *arg, struct altcp_pcb *accepted_conn, err_t err)
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127 | {
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128 | struct altcp_pcb *listen_conn = (struct altcp_pcb *)arg;
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129 | if (listen_conn && listen_conn->state && listen_conn->accept) {
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130 | err_t setup_err;
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131 | altcp_mbedtls_state_t *listen_state = (altcp_mbedtls_state_t *)listen_conn->state;
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132 | /* create a new altcp_conn to pass to the next 'accept' callback */
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133 | struct altcp_pcb *new_conn = altcp_alloc();
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134 | if (new_conn == NULL) {
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135 | return ERR_MEM;
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136 | }
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137 | setup_err = altcp_mbedtls_setup(listen_state->conf, new_conn, accepted_conn);
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138 | if (setup_err != ERR_OK) {
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139 | altcp_free(new_conn);
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140 | return setup_err;
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141 | }
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142 | return listen_conn->accept(listen_conn->arg, new_conn, err);
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143 | }
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144 | return ERR_ARG;
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145 | }
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146 |
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147 | /** Connected callback from lower connection (i.e. TCP).
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148 | * Not really implemented/tested yet...
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149 | */
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150 | static err_t
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151 | altcp_mbedtls_lower_connected(void *arg, struct altcp_pcb *inner_conn, err_t err)
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152 | {
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153 | struct altcp_pcb *conn = (struct altcp_pcb *)arg;
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154 | LWIP_UNUSED_ARG(inner_conn); /* for LWIP_NOASSERT */
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155 | if (conn && conn->state) {
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156 | LWIP_ASSERT("pcb mismatch", conn->inner_conn == inner_conn);
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157 | /* upper connected is called when handshake is done */
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158 | if (err != ERR_OK) {
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159 | if (conn->connected) {
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160 | return conn->connected(conn->arg, conn, err);
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161 | }
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162 | }
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163 | return altcp_mbedtls_lower_recv_process(conn, (altcp_mbedtls_state_t *)conn->state);
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164 | }
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165 | return ERR_VAL;
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166 | }
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167 |
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168 | /* Call recved for possibly more than an u16_t */
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169 | static void
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170 | altcp_mbedtls_lower_recved(struct altcp_pcb *inner_conn, int recvd_cnt)
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171 | {
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172 | while (recvd_cnt > 0) {
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173 | u16_t recvd_part = (u16_t)LWIP_MIN(recvd_cnt, 0xFFFF);
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174 | altcp_recved(inner_conn, recvd_part);
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175 | recvd_cnt -= recvd_part;
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176 | }
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177 | }
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178 |
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179 | /** Recv callback from lower connection (i.e. TCP)
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180 | * This one mainly differs between connection setup/handshake (data is fed into mbedTLS only)
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181 | * and application phase (data is decoded by mbedTLS and passed on to the application).
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182 | */
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183 | static err_t
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184 | altcp_mbedtls_lower_recv(void *arg, struct altcp_pcb *inner_conn, struct pbuf *p, err_t err)
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185 | {
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186 | altcp_mbedtls_state_t *state;
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187 | struct altcp_pcb *conn = (struct altcp_pcb *)arg;
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188 |
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189 | LWIP_ASSERT("no err expected", err == ERR_OK);
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190 | LWIP_UNUSED_ARG(err);
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191 |
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192 | if (!conn) {
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193 | /* no connection given as arg? should not happen, but prevent pbuf/conn leaks */
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194 | if (p != NULL) {
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195 | pbuf_free(p);
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196 | }
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197 | altcp_close(inner_conn);
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198 | return ERR_CLSD;
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199 | }
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200 | state = (altcp_mbedtls_state_t *)conn->state;
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201 | LWIP_ASSERT("pcb mismatch", conn->inner_conn == inner_conn);
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202 | if (!state) {
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203 | /* already closed */
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204 | if (p != NULL) {
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205 | pbuf_free(p);
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206 | }
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207 | altcp_close(inner_conn);
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208 | return ERR_CLSD;
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209 | }
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210 |
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211 | /* handle NULL pbuf (inner connection closed) */
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212 | if (p == NULL) {
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213 | /* remote host sent FIN, remember this (SSL state is destroyed
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214 | when both sides are closed only!) */
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215 | if ((state->flags & (ALTCP_MBEDTLS_FLAGS_HANDSHAKE_DONE | ALTCP_MBEDTLS_FLAGS_UPPER_CALLED)) ==
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216 | (ALTCP_MBEDTLS_FLAGS_HANDSHAKE_DONE | ALTCP_MBEDTLS_FLAGS_UPPER_CALLED)) {
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217 | /* need to notify upper layer (e.g. 'accept' called or 'connect' succeeded) */
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218 | if ((state->rx != NULL) || (state->rx_app != NULL)) {
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219 | state->flags |= ALTCP_MBEDTLS_FLAGS_RX_CLOSE_QUEUED;
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220 | /* this is a normal close (FIN) but we have unprocessed data, so delay the FIN */
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221 | altcp_mbedtls_handle_rx_appldata(conn, state);
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222 | return ERR_OK;
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223 | }
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224 | state->flags |= ALTCP_MBEDTLS_FLAGS_RX_CLOSED;
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225 | if (conn->recv) {
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226 | return conn->recv(conn->arg, conn, NULL, ERR_OK);
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227 | }
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228 | } else {
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229 | /* before connection setup is done: call 'err' */
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230 | if (conn->err) {
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231 | conn->err(conn->arg, ERR_CLSD);
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232 | }
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233 | altcp_close(conn);
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234 | }
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235 | return ERR_OK;
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236 | }
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237 |
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238 | /* If we come here, the connection is in good state (handshake phase or application data phase).
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239 | Queue up the pbuf for processing as handshake data or application data. */
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240 | if (state->rx == NULL) {
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241 | state->rx = p;
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242 | } else {
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243 | LWIP_ASSERT("rx pbuf overflow", (int)p->tot_len + (int)p->len <= 0xFFFF);
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244 | pbuf_cat(state->rx, p);
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245 | }
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246 | return altcp_mbedtls_lower_recv_process(conn, state);
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247 | }
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248 |
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249 | static err_t
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250 | altcp_mbedtls_lower_recv_process(struct altcp_pcb *conn, altcp_mbedtls_state_t *state)
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251 | {
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252 | if (!(state->flags & ALTCP_MBEDTLS_FLAGS_HANDSHAKE_DONE)) {
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253 | /* handle connection setup (handshake not done) */
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254 | int ret = mbedtls_ssl_handshake(&state->ssl_context);
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255 | /* try to send data... */
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256 | altcp_output(conn->inner_conn);
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257 | if (state->bio_bytes_read) {
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258 | /* acknowledge all bytes read */
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259 | altcp_mbedtls_lower_recved(conn->inner_conn, state->bio_bytes_read);
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260 | state->bio_bytes_read = 0;
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261 | }
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262 |
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263 | if (ret == MBEDTLS_ERR_SSL_WANT_READ || ret == MBEDTLS_ERR_SSL_WANT_WRITE) {
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264 | /* handshake not done, wait for more recv calls */
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265 | LWIP_ASSERT("in this state, the rx chain should be empty", state->rx == NULL);
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266 | return ERR_OK;
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267 | }
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268 | if (ret != 0) {
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269 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_ssl_handshake failed: %d\n", ret));
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270 | /* handshake failed, connection has to be closed */
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271 | if (conn->err) {
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272 | conn->err(conn->arg, ERR_CLSD);
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273 | }
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274 |
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275 | if (altcp_close(conn) != ERR_OK) {
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276 | altcp_abort(conn);
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277 | }
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278 | return ERR_OK;
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279 | }
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280 | /* If we come here, handshake succeeded. */
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281 | LWIP_ASSERT("state", state->bio_bytes_read == 0);
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282 | LWIP_ASSERT("state", state->bio_bytes_appl == 0);
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283 | state->flags |= ALTCP_MBEDTLS_FLAGS_HANDSHAKE_DONE;
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284 | /* issue "connect" callback" to upper connection (this can only happen for active open) */
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285 | if (conn->connected) {
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286 | err_t err;
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287 | err = conn->connected(conn->arg, conn, ERR_OK);
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288 | if (err != ERR_OK) {
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289 | return err;
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290 | }
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291 | }
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292 | if (state->rx == NULL) {
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293 | return ERR_OK;
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294 | }
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295 | }
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296 | /* handle application data */
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297 | return altcp_mbedtls_handle_rx_appldata(conn, state);
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298 | }
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299 |
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300 | /* Pass queued decoded rx data to application */
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301 | static err_t
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302 | altcp_mbedtls_pass_rx_data(struct altcp_pcb *conn, altcp_mbedtls_state_t *state)
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303 | {
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304 | err_t err;
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305 | struct pbuf *buf;
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306 | LWIP_ASSERT("conn != NULL", conn != NULL);
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307 | LWIP_ASSERT("state != NULL", state != NULL);
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308 | buf = state->rx_app;
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309 | if (buf) {
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310 | state->rx_app = NULL;
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311 | if (conn->recv) {
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312 | u16_t tot_len = buf->tot_len;
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313 | /* this needs to be increased first because the 'recved' call may come nested */
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314 | state->rx_passed_unrecved += tot_len;
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315 | state->flags |= ALTCP_MBEDTLS_FLAGS_UPPER_CALLED;
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316 | err = conn->recv(conn->arg, conn, buf, ERR_OK);
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317 | if (err != ERR_OK) {
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318 | if (err == ERR_ABRT) {
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319 | return ERR_ABRT;
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320 | }
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321 | /* not received, leave the pbuf(s) queued (and decrease 'unrecved' again) */
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322 | LWIP_ASSERT("state == conn->state", state == conn->state);
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323 | state->rx_app = buf;
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324 | state->rx_passed_unrecved -= tot_len;
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325 | LWIP_ASSERT("state->rx_passed_unrecved >= 0", state->rx_passed_unrecved >= 0);
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326 | if (state->rx_passed_unrecved < 0) {
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327 | state->rx_passed_unrecved = 0;
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328 | }
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329 | return err;
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330 | }
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331 | } else {
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332 | pbuf_free(buf);
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333 | }
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334 | } else if ((state->flags & (ALTCP_MBEDTLS_FLAGS_RX_CLOSE_QUEUED | ALTCP_MBEDTLS_FLAGS_RX_CLOSED)) ==
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335 | ALTCP_MBEDTLS_FLAGS_RX_CLOSE_QUEUED) {
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336 | state->flags |= ALTCP_MBEDTLS_FLAGS_RX_CLOSED;
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337 | if (conn->recv) {
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338 | return conn->recv(conn->arg, conn, NULL, ERR_OK);
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339 | }
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340 | }
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341 |
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342 | /* application may have close the connection */
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343 | if (conn->state != state) {
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344 | /* return error code to ensure altcp_mbedtls_handle_rx_appldata() exits the loop */
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345 | return ERR_CLSD;
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346 | }
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347 | return ERR_OK;
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348 | }
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349 |
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350 | /* Helper function that processes rx application data stored in rx pbuf chain */
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351 | static err_t
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352 | altcp_mbedtls_handle_rx_appldata(struct altcp_pcb *conn, altcp_mbedtls_state_t *state)
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353 | {
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354 | int ret;
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355 | LWIP_ASSERT("state != NULL", state != NULL);
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356 | if (!(state->flags & ALTCP_MBEDTLS_FLAGS_HANDSHAKE_DONE)) {
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357 | /* handshake not done yet */
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358 | return ERR_VAL;
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359 | }
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360 | do {
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361 | /* allocate a full-sized unchained PBUF_POOL: this is for RX! */
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362 | struct pbuf *buf = pbuf_alloc(PBUF_RAW, PBUF_POOL_BUFSIZE, PBUF_POOL);
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363 | if (buf == NULL) {
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364 | /* We're short on pbufs, try again later from 'poll' or 'recv' callbacks.
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365 | @todo: close on excessive allocation failures or leave this up to upper conn? */
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366 | return ERR_OK;
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367 | }
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368 |
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369 | /* decrypt application data, this pulls encrypted RX data off state->rx pbuf chain */
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370 | ret = mbedtls_ssl_read(&state->ssl_context, (unsigned char *)buf->payload, PBUF_POOL_BUFSIZE);
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371 | if (ret < 0) {
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372 | if (ret == MBEDTLS_ERR_SSL_CLIENT_RECONNECT) {
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373 | /* client is initiating a new connection using the same source port -> close connection or make handshake */
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374 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("new connection on same source port\n"));
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375 | LWIP_ASSERT("TODO: new connection on same source port, close this connection", 0);
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376 | } else if ((ret != MBEDTLS_ERR_SSL_WANT_READ) && (ret != MBEDTLS_ERR_SSL_WANT_WRITE)) {
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377 | if (ret == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY) {
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378 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("connection was closed gracefully\n"));
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379 | } else if (ret == MBEDTLS_ERR_NET_CONN_RESET) {
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380 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("connection was reset by peer\n"));
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381 | }
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382 | pbuf_free(buf);
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383 | return ERR_OK;
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384 | } else {
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385 | pbuf_free(buf);
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386 | return ERR_OK;
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387 | }
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388 | pbuf_free(buf);
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389 | altcp_abort(conn);
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390 | return ERR_ABRT;
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391 | } else {
|
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392 | err_t err;
|
---|
393 | if (ret) {
|
---|
394 | LWIP_ASSERT("bogus receive length", ret <= PBUF_POOL_BUFSIZE);
|
---|
395 | /* trim pool pbuf to actually decoded length */
|
---|
396 | pbuf_realloc(buf, (u16_t)ret);
|
---|
397 |
|
---|
398 | state->bio_bytes_appl += ret;
|
---|
399 | if (mbedtls_ssl_get_bytes_avail(&state->ssl_context) == 0) {
|
---|
400 | /* Record is done, now we know the share between application and protocol bytes
|
---|
401 | and can adjust the RX window by the protocol bytes.
|
---|
402 | The rest is 'recved' by the application calling our 'recved' fn. */
|
---|
403 | int overhead_bytes;
|
---|
404 | LWIP_ASSERT("bogus byte counts", state->bio_bytes_read > state->bio_bytes_appl);
|
---|
405 | overhead_bytes = state->bio_bytes_read - state->bio_bytes_appl;
|
---|
406 | altcp_mbedtls_lower_recved(conn->inner_conn, overhead_bytes);
|
---|
407 | state->bio_bytes_read = 0;
|
---|
408 | state->bio_bytes_appl = 0;
|
---|
409 | }
|
---|
410 |
|
---|
411 | if (state->rx_app == NULL) {
|
---|
412 | state->rx_app = buf;
|
---|
413 | } else {
|
---|
414 | pbuf_cat(state->rx_app, buf);
|
---|
415 | }
|
---|
416 | } else {
|
---|
417 | pbuf_free(buf);
|
---|
418 | buf = NULL;
|
---|
419 | }
|
---|
420 | err = altcp_mbedtls_pass_rx_data(conn, state);
|
---|
421 | if (err != ERR_OK) {
|
---|
422 | if (err == ERR_ABRT) {
|
---|
423 | /* recv callback needs to return this as the pcb is deallocated */
|
---|
424 | return ERR_ABRT;
|
---|
425 | }
|
---|
426 | /* we hide all other errors as we retry feeding the pbuf to the app later */
|
---|
427 | return ERR_OK;
|
---|
428 | }
|
---|
429 | }
|
---|
430 | } while (ret > 0);
|
---|
431 | return ERR_OK;
|
---|
432 | }
|
---|
433 |
|
---|
434 | /** Receive callback function called from mbedtls (set via mbedtls_ssl_set_bio)
|
---|
435 | * This function mainly copies data from pbufs and frees the pbufs after copying.
|
---|
436 | */
|
---|
437 | static int
|
---|
438 | altcp_mbedtls_bio_recv(void *ctx, unsigned char *buf, size_t len)
|
---|
439 | {
|
---|
440 | struct altcp_pcb *conn = (struct altcp_pcb *)ctx;
|
---|
441 | altcp_mbedtls_state_t *state;
|
---|
442 | struct pbuf *p;
|
---|
443 | u16_t ret;
|
---|
444 | u16_t copy_len;
|
---|
445 | err_t err;
|
---|
446 |
|
---|
447 | LWIP_UNUSED_ARG(err); /* for LWIP_NOASSERT */
|
---|
448 | if ((conn == NULL) || (conn->state == NULL)) {
|
---|
449 | return MBEDTLS_ERR_NET_INVALID_CONTEXT;
|
---|
450 | }
|
---|
451 | state = (altcp_mbedtls_state_t *)conn->state;
|
---|
452 | p = state->rx;
|
---|
453 |
|
---|
454 | /* @todo: return MBEDTLS_ERR_NET_CONN_RESET/MBEDTLS_ERR_NET_RECV_FAILED? */
|
---|
455 |
|
---|
456 | if ((p == NULL) || ((p->len == 0) && (p->next == NULL))) {
|
---|
457 | if (p) {
|
---|
458 | pbuf_free(p);
|
---|
459 | }
|
---|
460 | state->rx = NULL;
|
---|
461 | if ((state->flags & (ALTCP_MBEDTLS_FLAGS_RX_CLOSE_QUEUED | ALTCP_MBEDTLS_FLAGS_RX_CLOSED)) ==
|
---|
462 | ALTCP_MBEDTLS_FLAGS_RX_CLOSE_QUEUED) {
|
---|
463 | /* close queued but not passed up yet */
|
---|
464 | return 0;
|
---|
465 | }
|
---|
466 | return MBEDTLS_ERR_SSL_WANT_READ;
|
---|
467 | }
|
---|
468 | /* limit number of bytes again to copy from first pbuf in a chain only */
|
---|
469 | copy_len = (u16_t)LWIP_MIN(len, p->len);
|
---|
470 | /* copy the data */
|
---|
471 | ret = pbuf_copy_partial(p, buf, copy_len, 0);
|
---|
472 | LWIP_ASSERT("ret == copy_len", ret == copy_len);
|
---|
473 | /* hide the copied bytes from the pbuf */
|
---|
474 | err = pbuf_remove_header(p, ret);
|
---|
475 | LWIP_ASSERT("error", err == ERR_OK);
|
---|
476 | if (p->len == 0) {
|
---|
477 | /* the first pbuf has been fully read, free it */
|
---|
478 | state->rx = p->next;
|
---|
479 | p->next = NULL;
|
---|
480 | pbuf_free(p);
|
---|
481 | }
|
---|
482 |
|
---|
483 | state->bio_bytes_read += (int)ret;
|
---|
484 | return ret;
|
---|
485 | }
|
---|
486 |
|
---|
487 | /** Sent callback from lower connection (i.e. TCP)
|
---|
488 | * This only informs the upper layer to try to send more, not about
|
---|
489 | * the number of ACKed bytes.
|
---|
490 | */
|
---|
491 | static err_t
|
---|
492 | altcp_mbedtls_lower_sent(void *arg, struct altcp_pcb *inner_conn, u16_t len)
|
---|
493 | {
|
---|
494 | struct altcp_pcb *conn = (struct altcp_pcb *)arg;
|
---|
495 | LWIP_UNUSED_ARG(inner_conn); /* for LWIP_NOASSERT */
|
---|
496 | LWIP_UNUSED_ARG(len);
|
---|
497 | if (conn) {
|
---|
498 | altcp_mbedtls_state_t *state = (altcp_mbedtls_state_t *)conn->state;
|
---|
499 | LWIP_ASSERT("pcb mismatch", conn->inner_conn == inner_conn);
|
---|
500 | if (!state || !(state->flags & ALTCP_MBEDTLS_FLAGS_HANDSHAKE_DONE)) {
|
---|
501 | /* @todo: do something here? */
|
---|
502 | return ERR_OK;
|
---|
503 | }
|
---|
504 | /* try to send more if we failed before */
|
---|
505 | mbedtls_ssl_flush_output(&state->ssl_context);
|
---|
506 | /* call upper sent with len==0 if the application already sent data */
|
---|
507 | if ((state->flags & ALTCP_MBEDTLS_FLAGS_APPLDATA_SENT) && conn->sent) {
|
---|
508 | return conn->sent(conn->arg, conn, 0);
|
---|
509 | }
|
---|
510 | }
|
---|
511 | return ERR_OK;
|
---|
512 | }
|
---|
513 |
|
---|
514 | /** Poll callback from lower connection (i.e. TCP)
|
---|
515 | * Just pass this on to the application.
|
---|
516 | * @todo: retry sending?
|
---|
517 | */
|
---|
518 | static err_t
|
---|
519 | altcp_mbedtls_lower_poll(void *arg, struct altcp_pcb *inner_conn)
|
---|
520 | {
|
---|
521 | struct altcp_pcb *conn = (struct altcp_pcb *)arg;
|
---|
522 | LWIP_UNUSED_ARG(inner_conn); /* for LWIP_NOASSERT */
|
---|
523 | if (conn) {
|
---|
524 | LWIP_ASSERT("pcb mismatch", conn->inner_conn == inner_conn);
|
---|
525 | /* check if there's unreceived rx data */
|
---|
526 | if (conn->state) {
|
---|
527 | altcp_mbedtls_state_t *state = (altcp_mbedtls_state_t *)conn->state;
|
---|
528 | /* try to send more if we failed before */
|
---|
529 | mbedtls_ssl_flush_output(&state->ssl_context);
|
---|
530 | if (altcp_mbedtls_handle_rx_appldata(conn, state) == ERR_ABRT) {
|
---|
531 | return ERR_ABRT;
|
---|
532 | }
|
---|
533 | }
|
---|
534 | if (conn->poll) {
|
---|
535 | return conn->poll(conn->arg, conn);
|
---|
536 | }
|
---|
537 | }
|
---|
538 | return ERR_OK;
|
---|
539 | }
|
---|
540 |
|
---|
541 | static void
|
---|
542 | altcp_mbedtls_lower_err(void *arg, err_t err)
|
---|
543 | {
|
---|
544 | struct altcp_pcb *conn = (struct altcp_pcb *)arg;
|
---|
545 | if (conn) {
|
---|
546 | conn->inner_conn = NULL; /* already freed */
|
---|
547 | if (conn->err) {
|
---|
548 | conn->err(conn->arg, err);
|
---|
549 | }
|
---|
550 | altcp_free(conn);
|
---|
551 | }
|
---|
552 | }
|
---|
553 |
|
---|
554 | /* setup functions */
|
---|
555 |
|
---|
556 | static void
|
---|
557 | altcp_mbedtls_remove_callbacks(struct altcp_pcb *inner_conn)
|
---|
558 | {
|
---|
559 | altcp_arg(inner_conn, NULL);
|
---|
560 | altcp_recv(inner_conn, NULL);
|
---|
561 | altcp_sent(inner_conn, NULL);
|
---|
562 | altcp_err(inner_conn, NULL);
|
---|
563 | altcp_poll(inner_conn, NULL, inner_conn->pollinterval);
|
---|
564 | }
|
---|
565 |
|
---|
566 | static void
|
---|
567 | altcp_mbedtls_setup_callbacks(struct altcp_pcb *conn, struct altcp_pcb *inner_conn)
|
---|
568 | {
|
---|
569 | altcp_arg(inner_conn, conn);
|
---|
570 | altcp_recv(inner_conn, altcp_mbedtls_lower_recv);
|
---|
571 | altcp_sent(inner_conn, altcp_mbedtls_lower_sent);
|
---|
572 | altcp_err(inner_conn, altcp_mbedtls_lower_err);
|
---|
573 | /* tcp_poll is set when interval is set by application */
|
---|
574 | /* listen is set totally different :-) */
|
---|
575 | }
|
---|
576 |
|
---|
577 | static err_t
|
---|
578 | altcp_mbedtls_setup(void *conf, struct altcp_pcb *conn, struct altcp_pcb *inner_conn)
|
---|
579 | {
|
---|
580 | int ret;
|
---|
581 | struct altcp_tls_config *config = (struct altcp_tls_config *)conf;
|
---|
582 | altcp_mbedtls_state_t *state;
|
---|
583 | if (!conf) {
|
---|
584 | return ERR_ARG;
|
---|
585 | }
|
---|
586 | LWIP_ASSERT("invalid inner_conn", conn != inner_conn);
|
---|
587 |
|
---|
588 | /* allocate mbedtls context */
|
---|
589 | state = altcp_mbedtls_alloc(conf);
|
---|
590 | if (state == NULL) {
|
---|
591 | return ERR_MEM;
|
---|
592 | }
|
---|
593 | /* initialize mbedtls context: */
|
---|
594 | mbedtls_ssl_init(&state->ssl_context);
|
---|
595 | ret = mbedtls_ssl_setup(&state->ssl_context, &config->conf);
|
---|
596 | if (ret != 0) {
|
---|
597 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_ssl_setup failed\n"));
|
---|
598 | /* @todo: convert 'ret' to err_t */
|
---|
599 | altcp_mbedtls_free(conf, state);
|
---|
600 | return ERR_MEM;
|
---|
601 | }
|
---|
602 | /* tell mbedtls about our I/O functions */
|
---|
603 | mbedtls_ssl_set_bio(&state->ssl_context, conn, altcp_mbedtls_bio_send, altcp_mbedtls_bio_recv, NULL);
|
---|
604 |
|
---|
605 | altcp_mbedtls_setup_callbacks(conn, inner_conn);
|
---|
606 | conn->inner_conn = inner_conn;
|
---|
607 | conn->fns = &altcp_mbedtls_functions;
|
---|
608 | conn->state = state;
|
---|
609 | return ERR_OK;
|
---|
610 | }
|
---|
611 |
|
---|
612 | struct altcp_pcb *
|
---|
613 | altcp_tls_wrap(struct altcp_tls_config *config, struct altcp_pcb *inner_pcb)
|
---|
614 | {
|
---|
615 | struct altcp_pcb *ret;
|
---|
616 | if (inner_pcb == NULL) {
|
---|
617 | return NULL;
|
---|
618 | }
|
---|
619 | ret = altcp_alloc();
|
---|
620 | if (ret != NULL) {
|
---|
621 | if (altcp_mbedtls_setup(config, ret, inner_pcb) != ERR_OK) {
|
---|
622 | altcp_free(ret);
|
---|
623 | return NULL;
|
---|
624 | }
|
---|
625 | }
|
---|
626 | return ret;
|
---|
627 | }
|
---|
628 |
|
---|
629 | void *
|
---|
630 | altcp_tls_context(struct altcp_pcb *conn)
|
---|
631 | {
|
---|
632 | if (conn && conn->state) {
|
---|
633 | altcp_mbedtls_state_t *state = (altcp_mbedtls_state_t *)conn->state;
|
---|
634 | return &state->ssl_context;
|
---|
635 | }
|
---|
636 | return NULL;
|
---|
637 | }
|
---|
638 |
|
---|
639 | #if ALTCP_MBEDTLS_DEBUG != LWIP_DBG_OFF
|
---|
640 | static void
|
---|
641 | altcp_mbedtls_debug(void *ctx, int level, const char *file, int line, const char *str)
|
---|
642 | {
|
---|
643 | LWIP_UNUSED_ARG(ctx);
|
---|
644 | LWIP_UNUSED_ARG(level);
|
---|
645 | LWIP_UNUSED_ARG(file);
|
---|
646 | LWIP_UNUSED_ARG(line);
|
---|
647 | LWIP_UNUSED_ARG(str);
|
---|
648 |
|
---|
649 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("%s:%04d: %s", file, line, str));
|
---|
650 | }
|
---|
651 | #endif
|
---|
652 |
|
---|
653 | #ifndef ALTCP_MBEDTLS_RNG_FN
|
---|
654 | /** ATTENTION: It is *really* important to *NOT* use this dummy RNG in production code!!!! */
|
---|
655 | static int
|
---|
656 | dummy_rng(void *ctx, unsigned char *buffer, size_t len)
|
---|
657 | {
|
---|
658 | static size_t ctr;
|
---|
659 | size_t i;
|
---|
660 | LWIP_UNUSED_ARG(ctx);
|
---|
661 | for (i = 0; i < len; i++) {
|
---|
662 | buffer[i] = (unsigned char)++ctr;
|
---|
663 | }
|
---|
664 | return 0;
|
---|
665 | }
|
---|
666 | #define ALTCP_MBEDTLS_RNG_FN dummy_rng
|
---|
667 | #endif /* ALTCP_MBEDTLS_RNG_FN */
|
---|
668 |
|
---|
669 | /** Create new TLS configuration
|
---|
670 | * ATTENTION: Server certificate and private key have to be added outside this function!
|
---|
671 | */
|
---|
672 | static struct altcp_tls_config *
|
---|
673 | altcp_tls_create_config(int is_server, int have_cert, int have_pkey, int have_ca)
|
---|
674 | {
|
---|
675 | size_t sz;
|
---|
676 | int ret;
|
---|
677 | struct altcp_tls_config *conf;
|
---|
678 | mbedtls_x509_crt *mem;
|
---|
679 |
|
---|
680 | if (TCP_WND < MBEDTLS_SSL_MAX_CONTENT_LEN) {
|
---|
681 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG|LWIP_DBG_LEVEL_SERIOUS,
|
---|
682 | ("altcp_tls: TCP_WND is smaller than the RX decryption buffer, connection RX might stall!\n"));
|
---|
683 | }
|
---|
684 |
|
---|
685 | altcp_mbedtls_mem_init();
|
---|
686 |
|
---|
687 | sz = sizeof(struct altcp_tls_config);
|
---|
688 | if (have_cert) {
|
---|
689 | sz += sizeof(mbedtls_x509_crt);
|
---|
690 | }
|
---|
691 | if (have_ca) {
|
---|
692 | sz += sizeof(mbedtls_x509_crt);
|
---|
693 | }
|
---|
694 | if (have_pkey) {
|
---|
695 | sz += sizeof(mbedtls_pk_context);
|
---|
696 | }
|
---|
697 |
|
---|
698 | conf = (struct altcp_tls_config *)altcp_mbedtls_alloc_config(sz);
|
---|
699 | if (conf == NULL) {
|
---|
700 | return NULL;
|
---|
701 | }
|
---|
702 | mem = (mbedtls_x509_crt *)(conf + 1);
|
---|
703 | if (have_cert) {
|
---|
704 | conf->cert = mem;
|
---|
705 | mem++;
|
---|
706 | }
|
---|
707 | if (have_ca) {
|
---|
708 | conf->ca = mem;
|
---|
709 | mem++;
|
---|
710 | }
|
---|
711 | if (have_pkey) {
|
---|
712 | conf->pkey = (mbedtls_pk_context *)mem;
|
---|
713 | }
|
---|
714 |
|
---|
715 | mbedtls_ssl_config_init(&conf->conf);
|
---|
716 | mbedtls_entropy_init(&conf->entropy);
|
---|
717 | mbedtls_ctr_drbg_init(&conf->ctr_drbg);
|
---|
718 |
|
---|
719 | /* Seed the RNG */
|
---|
720 | ret = mbedtls_ctr_drbg_seed(&conf->ctr_drbg, ALTCP_MBEDTLS_RNG_FN, &conf->entropy, ALTCP_MBEDTLS_ENTROPY_PTR, ALTCP_MBEDTLS_ENTROPY_LEN);
|
---|
721 | if (ret != 0) {
|
---|
722 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_ctr_drbg_seed failed: %d\n", ret));
|
---|
723 | altcp_mbedtls_free_config(conf);
|
---|
724 | return NULL;
|
---|
725 | }
|
---|
726 |
|
---|
727 | /* Setup ssl context (@todo: what's different for a client here? -> might better be done on listen/connect) */
|
---|
728 | ret = mbedtls_ssl_config_defaults(&conf->conf, is_server ? MBEDTLS_SSL_IS_SERVER : MBEDTLS_SSL_IS_CLIENT,
|
---|
729 | MBEDTLS_SSL_TRANSPORT_STREAM, MBEDTLS_SSL_PRESET_DEFAULT);
|
---|
730 | if (ret != 0) {
|
---|
731 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_ssl_config_defaults failed: %d\n", ret));
|
---|
732 | altcp_mbedtls_free_config(conf);
|
---|
733 | return NULL;
|
---|
734 | }
|
---|
735 | mbedtls_ssl_conf_authmode(&conf->conf, MBEDTLS_SSL_VERIFY_OPTIONAL);
|
---|
736 |
|
---|
737 | mbedtls_ssl_conf_rng(&conf->conf, mbedtls_ctr_drbg_random, &conf->ctr_drbg);
|
---|
738 | #if ALTCP_MBEDTLS_DEBUG != LWIP_DBG_OFF
|
---|
739 | mbedtls_ssl_conf_dbg(&conf->conf, altcp_mbedtls_debug, stdout);
|
---|
740 | #endif
|
---|
741 | #if defined(MBEDTLS_SSL_CACHE_C) && ALTCP_MBEDTLS_SESSION_CACHE_TIMEOUT_SECONDS
|
---|
742 | mbedtls_ssl_conf_session_cache(&conf->conf, &conf->cache, mbedtls_ssl_cache_get, mbedtls_ssl_cache_set);
|
---|
743 | mbedtls_ssl_cache_set_timeout(&conf->cache, 30);
|
---|
744 | mbedtls_ssl_cache_set_max_entries(&conf->cache, 30);
|
---|
745 | #endif
|
---|
746 |
|
---|
747 | return conf;
|
---|
748 | }
|
---|
749 |
|
---|
750 | /** Create new TLS configuration
|
---|
751 | * This is a suboptimal version that gets the encrypted private key and its password,
|
---|
752 | * as well as the server certificate.
|
---|
753 | */
|
---|
754 | struct altcp_tls_config *
|
---|
755 | altcp_tls_create_config_server_privkey_cert(const u8_t *privkey, size_t privkey_len,
|
---|
756 | const u8_t *privkey_pass, size_t privkey_pass_len,
|
---|
757 | const u8_t *cert, size_t cert_len)
|
---|
758 | {
|
---|
759 | int ret;
|
---|
760 | mbedtls_x509_crt *srvcert;
|
---|
761 | mbedtls_pk_context *pkey;
|
---|
762 | struct altcp_tls_config *conf = altcp_tls_create_config(1, 1, 1, 0);
|
---|
763 | if (conf == NULL) {
|
---|
764 | return NULL;
|
---|
765 | }
|
---|
766 |
|
---|
767 | srvcert = conf->cert;
|
---|
768 | mbedtls_x509_crt_init(srvcert);
|
---|
769 |
|
---|
770 | pkey = conf->pkey;
|
---|
771 | mbedtls_pk_init(pkey);
|
---|
772 |
|
---|
773 | /* Load the certificates and private key */
|
---|
774 | ret = mbedtls_x509_crt_parse(srvcert, cert, cert_len);
|
---|
775 | if (ret != 0) {
|
---|
776 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_x509_crt_parse failed: %d\n", ret));
|
---|
777 | altcp_mbedtls_free_config(conf);
|
---|
778 | return NULL;
|
---|
779 | }
|
---|
780 |
|
---|
781 | ret = mbedtls_pk_parse_key(pkey, (const unsigned char *) privkey, privkey_len, privkey_pass, privkey_pass_len);
|
---|
782 | if (ret != 0) {
|
---|
783 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_pk_parse_public_key failed: %d\n", ret));
|
---|
784 | mbedtls_x509_crt_free(srvcert);
|
---|
785 | altcp_mbedtls_free_config(conf);
|
---|
786 | return NULL;
|
---|
787 | }
|
---|
788 |
|
---|
789 | mbedtls_ssl_conf_ca_chain(&conf->conf, srvcert->next, NULL);
|
---|
790 | ret = mbedtls_ssl_conf_own_cert(&conf->conf, srvcert, pkey);
|
---|
791 | if (ret != 0) {
|
---|
792 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_ssl_conf_own_cert failed: %d\n", ret));
|
---|
793 | mbedtls_x509_crt_free(srvcert);
|
---|
794 | mbedtls_pk_free(pkey);
|
---|
795 | altcp_mbedtls_free_config(conf);
|
---|
796 | return NULL;
|
---|
797 | }
|
---|
798 | return conf;
|
---|
799 | }
|
---|
800 |
|
---|
801 | static struct altcp_tls_config *
|
---|
802 | altcp_tls_create_config_client_common(const u8_t *ca, size_t ca_len, int is_2wayauth)
|
---|
803 | {
|
---|
804 | int ret;
|
---|
805 | struct altcp_tls_config *conf = altcp_tls_create_config(0, is_2wayauth, is_2wayauth, ca != NULL);
|
---|
806 | if (conf == NULL) {
|
---|
807 | return NULL;
|
---|
808 | }
|
---|
809 |
|
---|
810 | /* Initialize the CA certificate if provided
|
---|
811 | * CA certificate is optional (to save memory) but recommended for production environment
|
---|
812 | * Without CA certificate, connection will be prone to man-in-the-middle attacks */
|
---|
813 | if (ca) {
|
---|
814 | mbedtls_x509_crt_init(conf->ca);
|
---|
815 | ret = mbedtls_x509_crt_parse(conf->ca, ca, ca_len);
|
---|
816 | if (ret != 0) {
|
---|
817 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_x509_crt_parse ca failed: %d 0x%x", ret, -1*ret));
|
---|
818 | altcp_mbedtls_free_config(conf);
|
---|
819 | return NULL;
|
---|
820 | }
|
---|
821 |
|
---|
822 | mbedtls_ssl_conf_ca_chain(&conf->conf, conf->ca, NULL);
|
---|
823 | }
|
---|
824 | return conf;
|
---|
825 | }
|
---|
826 |
|
---|
827 | struct altcp_tls_config *
|
---|
828 | altcp_tls_create_config_client(const u8_t *ca, size_t ca_len)
|
---|
829 | {
|
---|
830 | return altcp_tls_create_config_client_common(ca, ca_len, 0);
|
---|
831 | }
|
---|
832 |
|
---|
833 | struct altcp_tls_config *
|
---|
834 | altcp_tls_create_config_client_2wayauth(const u8_t *ca, size_t ca_len, const u8_t *privkey, size_t privkey_len,
|
---|
835 | const u8_t *privkey_pass, size_t privkey_pass_len,
|
---|
836 | const u8_t *cert, size_t cert_len)
|
---|
837 | {
|
---|
838 | int ret;
|
---|
839 | struct altcp_tls_config *conf;
|
---|
840 |
|
---|
841 | if (!cert || !privkey) {
|
---|
842 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("altcp_tls_create_config_client_2wayauth: certificate and priv key required"));
|
---|
843 | return NULL;
|
---|
844 | }
|
---|
845 |
|
---|
846 | conf = altcp_tls_create_config_client_common(ca, ca_len, 1);
|
---|
847 | if (conf == NULL) {
|
---|
848 | return NULL;
|
---|
849 | }
|
---|
850 |
|
---|
851 | /* Initialize the client certificate and corresponding private key */
|
---|
852 | mbedtls_x509_crt_init(conf->cert);
|
---|
853 | ret = mbedtls_x509_crt_parse(conf->cert, cert, cert_len);
|
---|
854 | if (ret != 0) {
|
---|
855 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_x509_crt_parse cert failed: %d 0x%x", ret, -1*ret));
|
---|
856 | altcp_mbedtls_free_config(conf->cert);
|
---|
857 | return NULL;
|
---|
858 | }
|
---|
859 |
|
---|
860 | mbedtls_pk_init(conf->pkey);
|
---|
861 | ret = mbedtls_pk_parse_key(conf->pkey, privkey, privkey_len, privkey_pass, privkey_pass_len);
|
---|
862 | if (ret != 0) {
|
---|
863 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_pk_parse_key failed: %d 0x%x", ret, -1*ret));
|
---|
864 | altcp_mbedtls_free_config(conf);
|
---|
865 | return NULL;
|
---|
866 | }
|
---|
867 |
|
---|
868 | ret = mbedtls_ssl_conf_own_cert(&conf->conf, conf->cert, conf->pkey);
|
---|
869 | if (ret != 0) {
|
---|
870 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_ssl_conf_own_cert failed: %d 0x%x", ret, -1*ret));
|
---|
871 | altcp_mbedtls_free_config(conf);
|
---|
872 | return NULL;
|
---|
873 | }
|
---|
874 |
|
---|
875 | return conf;
|
---|
876 | }
|
---|
877 |
|
---|
878 | void
|
---|
879 | altcp_tls_free_config(struct altcp_tls_config *conf)
|
---|
880 | {
|
---|
881 | if (conf->pkey) {
|
---|
882 | mbedtls_pk_free(conf->pkey);
|
---|
883 | }
|
---|
884 | if (conf->cert) {
|
---|
885 | mbedtls_x509_crt_free(conf->cert);
|
---|
886 | }
|
---|
887 | if (conf->ca) {
|
---|
888 | mbedtls_x509_crt_free(conf->ca);
|
---|
889 | }
|
---|
890 | altcp_mbedtls_free_config(conf);
|
---|
891 | }
|
---|
892 |
|
---|
893 | /* "virtual" functions */
|
---|
894 | static void
|
---|
895 | altcp_mbedtls_set_poll(struct altcp_pcb *conn, u8_t interval)
|
---|
896 | {
|
---|
897 | if (conn != NULL) {
|
---|
898 | altcp_poll(conn->inner_conn, altcp_mbedtls_lower_poll, interval);
|
---|
899 | }
|
---|
900 | }
|
---|
901 |
|
---|
902 | static void
|
---|
903 | altcp_mbedtls_recved(struct altcp_pcb *conn, u16_t len)
|
---|
904 | {
|
---|
905 | u16_t lower_recved;
|
---|
906 | altcp_mbedtls_state_t *state;
|
---|
907 | if (conn == NULL) {
|
---|
908 | return;
|
---|
909 | }
|
---|
910 | state = (altcp_mbedtls_state_t *)conn->state;
|
---|
911 | if (state == NULL) {
|
---|
912 | return;
|
---|
913 | }
|
---|
914 | if (!(state->flags & ALTCP_MBEDTLS_FLAGS_HANDSHAKE_DONE)) {
|
---|
915 | return;
|
---|
916 | }
|
---|
917 | lower_recved = len;
|
---|
918 | if (lower_recved > state->rx_passed_unrecved) {
|
---|
919 | LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("bogus recved count (len > state->rx_passed_unrecved / %d / %d)",
|
---|
920 | len, state->rx_passed_unrecved));
|
---|
921 | lower_recved = (u16_t)state->rx_passed_unrecved;
|
---|
922 | }
|
---|
923 | state->rx_passed_unrecved -= lower_recved;
|
---|
924 |
|
---|
925 | altcp_recved(conn->inner_conn, lower_recved);
|
---|
926 | }
|
---|
927 |
|
---|
928 | static err_t
|
---|
929 | altcp_mbedtls_connect(struct altcp_pcb *conn, const ip_addr_t *ipaddr, u16_t port, altcp_connected_fn connected)
|
---|
930 | {
|
---|
931 | if (conn == NULL) {
|
---|
932 | return ERR_VAL;
|
---|
933 | }
|
---|
934 | conn->connected = connected;
|
---|
935 | return altcp_connect(conn->inner_conn, ipaddr, port, altcp_mbedtls_lower_connected);
|
---|
936 | }
|
---|
937 |
|
---|
938 | static struct altcp_pcb *
|
---|
939 | altcp_mbedtls_listen(struct altcp_pcb *conn, u8_t backlog, err_t *err)
|
---|
940 | {
|
---|
941 | struct altcp_pcb *lpcb;
|
---|
942 | if (conn == NULL) {
|
---|
943 | return NULL;
|
---|
944 | }
|
---|
945 | lpcb = altcp_listen_with_backlog_and_err(conn->inner_conn, backlog, err);
|
---|
946 | if (lpcb != NULL) {
|
---|
947 | conn->inner_conn = lpcb;
|
---|
948 | altcp_accept(lpcb, altcp_mbedtls_lower_accept);
|
---|
949 | return conn;
|
---|
950 | }
|
---|
951 | return NULL;
|
---|
952 | }
|
---|
953 |
|
---|
954 | static void
|
---|
955 | altcp_mbedtls_abort(struct altcp_pcb *conn)
|
---|
956 | {
|
---|
957 | if (conn != NULL) {
|
---|
958 | altcp_abort(conn->inner_conn);
|
---|
959 | }
|
---|
960 | }
|
---|
961 |
|
---|
962 | static err_t
|
---|
963 | altcp_mbedtls_close(struct altcp_pcb *conn)
|
---|
964 | {
|
---|
965 | struct altcp_pcb *inner_conn;
|
---|
966 | if (conn == NULL) {
|
---|
967 | return ERR_VAL;
|
---|
968 | }
|
---|
969 | inner_conn = conn->inner_conn;
|
---|
970 | if (inner_conn) {
|
---|
971 | err_t err;
|
---|
972 | altcp_poll_fn oldpoll = inner_conn->poll;
|
---|
973 | altcp_mbedtls_remove_callbacks(conn->inner_conn);
|
---|
974 | err = altcp_close(conn->inner_conn);
|
---|
975 | if (err != ERR_OK) {
|
---|
976 | /* not closed, set up all callbacks again */
|
---|
977 | altcp_mbedtls_setup_callbacks(conn, inner_conn);
|
---|
978 | /* poll callback is not included in the above */
|
---|
979 | altcp_poll(inner_conn, oldpoll, inner_conn->pollinterval);
|
---|
980 | return err;
|
---|
981 | }
|
---|
982 | conn->inner_conn = NULL;
|
---|
983 | }
|
---|
984 | altcp_free(conn);
|
---|
985 | return ERR_OK;
|
---|
986 | }
|
---|
987 |
|
---|
988 | /** Allow caller of altcp_write() to limit to negotiated chunk size
|
---|
989 | * or remaining sndbuf space of inner_conn.
|
---|
990 | */
|
---|
991 | static u16_t
|
---|
992 | altcp_mbedtls_sndbuf(struct altcp_pcb *conn)
|
---|
993 | {
|
---|
994 | if (conn) {
|
---|
995 | altcp_mbedtls_state_t *state;
|
---|
996 | state = (altcp_mbedtls_state_t*)conn->state;
|
---|
997 | if (!state || !(state->flags & ALTCP_MBEDTLS_FLAGS_HANDSHAKE_DONE)) {
|
---|
998 | return 0;
|
---|
999 | }
|
---|
1000 | if (conn->inner_conn) {
|
---|
1001 | u16_t sndbuf = altcp_sndbuf(conn->inner_conn);
|
---|
1002 | /* Take care of record header, IV, AuthTag */
|
---|
1003 | int ssl_expan = mbedtls_ssl_get_record_expansion(&state->ssl_context);
|
---|
1004 | if (ssl_expan > 0) {
|
---|
1005 | size_t ssl_added = (u16_t)LWIP_MIN(ssl_expan, 0xFFFF);
|
---|
1006 | /* internal sndbuf smaller than our offset */
|
---|
1007 | if (ssl_added < sndbuf) {
|
---|
1008 | size_t max_len = 0xFFFF;
|
---|
1009 | size_t ret;
|
---|
1010 | #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
|
---|
1011 | /* @todo: adjust ssl_added to real value related to negociated cipher */
|
---|
1012 | size_t max_frag_len = mbedtls_ssl_get_max_frag_len(&state->ssl_context);
|
---|
1013 | max_len = LWIP_MIN(max_frag_len, max_len);
|
---|
1014 | #endif
|
---|
1015 | /* Adjust sndbuf of inner_conn with what added by SSL */
|
---|
1016 | ret = LWIP_MIN(sndbuf - ssl_added, max_len);
|
---|
1017 | LWIP_ASSERT("sndbuf overflow", ret <= 0xFFFF);
|
---|
1018 | return (u16_t)ret;
|
---|
1019 | }
|
---|
1020 | }
|
---|
1021 | }
|
---|
1022 | }
|
---|
1023 | /* fallback: use sendbuf of the inner connection */
|
---|
1024 | return altcp_default_sndbuf(conn);
|
---|
1025 | }
|
---|
1026 |
|
---|
1027 | /** Write data to a TLS connection. Calls into mbedTLS, which in turn calls into
|
---|
1028 | * @ref altcp_mbedtls_bio_send() to send the encrypted data
|
---|
1029 | */
|
---|
1030 | static err_t
|
---|
1031 | altcp_mbedtls_write(struct altcp_pcb *conn, const void *dataptr, u16_t len, u8_t apiflags)
|
---|
1032 | {
|
---|
1033 | int ret;
|
---|
1034 | altcp_mbedtls_state_t *state;
|
---|
1035 |
|
---|
1036 | LWIP_UNUSED_ARG(apiflags);
|
---|
1037 |
|
---|
1038 | if (conn == NULL) {
|
---|
1039 | return ERR_VAL;
|
---|
1040 | }
|
---|
1041 |
|
---|
1042 | state = (altcp_mbedtls_state_t *)conn->state;
|
---|
1043 | if (state == NULL) {
|
---|
1044 | /* @todo: which error? */
|
---|
1045 | return ERR_CLSD;
|
---|
1046 | }
|
---|
1047 | if (!(state->flags & ALTCP_MBEDTLS_FLAGS_HANDSHAKE_DONE)) {
|
---|
1048 | /* @todo: which error? */
|
---|
1049 | return ERR_VAL;
|
---|
1050 | }
|
---|
1051 |
|
---|
1052 | /* HACK: if thre is something left to send, try to flush it and only
|
---|
1053 | allow sending more if this succeeded (this is a hack because neither
|
---|
1054 | returning 0 nor MBEDTLS_ERR_SSL_WANT_WRITE worked for me) */
|
---|
1055 | if (state->ssl_context.out_left) {
|
---|
1056 | mbedtls_ssl_flush_output(&state->ssl_context);
|
---|
1057 | if (state->ssl_context.out_left) {
|
---|
1058 | return ERR_MEM;
|
---|
1059 | }
|
---|
1060 | }
|
---|
1061 | ret = mbedtls_ssl_write(&state->ssl_context, (const unsigned char *)dataptr, len);
|
---|
1062 | /* try to send data... */
|
---|
1063 | altcp_output(conn->inner_conn);
|
---|
1064 | if (ret >= 0) {
|
---|
1065 | if (ret == len) {
|
---|
1066 | state->flags |= ALTCP_MBEDTLS_FLAGS_APPLDATA_SENT;
|
---|
1067 | return ERR_OK;
|
---|
1068 | } else {
|
---|
1069 | /* @todo/@fixme: assumption: either everything sent or error */
|
---|
1070 | LWIP_ASSERT("ret <= 0", 0);
|
---|
1071 | return ERR_MEM;
|
---|
1072 | }
|
---|
1073 | } else {
|
---|
1074 | if (ret == MBEDTLS_ERR_SSL_WANT_WRITE) {
|
---|
1075 | /* @todo: convert error to err_t */
|
---|
1076 | return ERR_MEM;
|
---|
1077 | }
|
---|
1078 | LWIP_ASSERT("unhandled error", 0);
|
---|
1079 | return ERR_VAL;
|
---|
1080 | }
|
---|
1081 | }
|
---|
1082 |
|
---|
1083 | /** Send callback function called from mbedtls (set via mbedtls_ssl_set_bio)
|
---|
1084 | * This function is either called during handshake or when sending application
|
---|
1085 | * data via @ref altcp_mbedtls_write (or altcp_write)
|
---|
1086 | */
|
---|
1087 | static int
|
---|
1088 | altcp_mbedtls_bio_send(void *ctx, const unsigned char *dataptr, size_t size)
|
---|
1089 | {
|
---|
1090 | struct altcp_pcb *conn = (struct altcp_pcb *) ctx;
|
---|
1091 | int written = 0;
|
---|
1092 | size_t size_left = size;
|
---|
1093 | u8_t apiflags = TCP_WRITE_FLAG_COPY;
|
---|
1094 |
|
---|
1095 | LWIP_ASSERT("conn != NULL", conn != NULL);
|
---|
1096 | if ((conn == NULL) || (conn->inner_conn == NULL)) {
|
---|
1097 | return MBEDTLS_ERR_NET_INVALID_CONTEXT;
|
---|
1098 | }
|
---|
1099 |
|
---|
1100 | while (size_left) {
|
---|
1101 | u16_t write_len = (u16_t)LWIP_MIN(size_left, 0xFFFF);
|
---|
1102 | err_t err = altcp_write(conn->inner_conn, (const void *)dataptr, write_len, apiflags);
|
---|
1103 | if (err == ERR_OK) {
|
---|
1104 | written += write_len;
|
---|
1105 | size_left -= write_len;
|
---|
1106 | } else if (err == ERR_MEM) {
|
---|
1107 | if (written) {
|
---|
1108 | return written;
|
---|
1109 | }
|
---|
1110 | return 0; /* MBEDTLS_ERR_SSL_WANT_WRITE; */
|
---|
1111 | } else {
|
---|
1112 | LWIP_ASSERT("tls_write, tcp_write: err != ERR MEM", 0);
|
---|
1113 | /* @todo: return MBEDTLS_ERR_NET_CONN_RESET or MBEDTLS_ERR_NET_SEND_FAILED */
|
---|
1114 | return MBEDTLS_ERR_NET_SEND_FAILED;
|
---|
1115 | }
|
---|
1116 | }
|
---|
1117 | return written;
|
---|
1118 | }
|
---|
1119 |
|
---|
1120 | static u16_t
|
---|
1121 | altcp_mbedtls_mss(struct altcp_pcb *conn)
|
---|
1122 | {
|
---|
1123 | if (conn == NULL) {
|
---|
1124 | return 0;
|
---|
1125 | }
|
---|
1126 | /* @todo: LWIP_MIN(mss, mbedtls_ssl_get_max_frag_len()) ? */
|
---|
1127 | return altcp_mss(conn->inner_conn);
|
---|
1128 | }
|
---|
1129 |
|
---|
1130 | static void
|
---|
1131 | altcp_mbedtls_dealloc(struct altcp_pcb *conn)
|
---|
1132 | {
|
---|
1133 | /* clean up and free tls state */
|
---|
1134 | if (conn) {
|
---|
1135 | altcp_mbedtls_state_t *state = (altcp_mbedtls_state_t *)conn->state;
|
---|
1136 | if (state) {
|
---|
1137 | mbedtls_ssl_free(&state->ssl_context);
|
---|
1138 | state->flags = 0;
|
---|
1139 | if (state->rx) {
|
---|
1140 | /* free leftover (unhandled) rx pbufs */
|
---|
1141 | pbuf_free(state->rx);
|
---|
1142 | state->rx = NULL;
|
---|
1143 | }
|
---|
1144 | altcp_mbedtls_free(state->conf, state);
|
---|
1145 | conn->state = NULL;
|
---|
1146 | }
|
---|
1147 | }
|
---|
1148 | }
|
---|
1149 |
|
---|
1150 | const struct altcp_functions altcp_mbedtls_functions = {
|
---|
1151 | altcp_mbedtls_set_poll,
|
---|
1152 | altcp_mbedtls_recved,
|
---|
1153 | altcp_default_bind,
|
---|
1154 | altcp_mbedtls_connect,
|
---|
1155 | altcp_mbedtls_listen,
|
---|
1156 | altcp_mbedtls_abort,
|
---|
1157 | altcp_mbedtls_close,
|
---|
1158 | altcp_default_shutdown,
|
---|
1159 | altcp_mbedtls_write,
|
---|
1160 | altcp_default_output,
|
---|
1161 | altcp_mbedtls_mss,
|
---|
1162 | altcp_mbedtls_sndbuf,
|
---|
1163 | altcp_default_sndqueuelen,
|
---|
1164 | altcp_default_nagle_disable,
|
---|
1165 | altcp_default_nagle_enable,
|
---|
1166 | altcp_default_nagle_disabled,
|
---|
1167 | altcp_default_setprio,
|
---|
1168 | altcp_mbedtls_dealloc,
|
---|
1169 | altcp_default_get_tcp_addrinfo,
|
---|
1170 | altcp_default_get_ip,
|
---|
1171 | altcp_default_get_port
|
---|
1172 | #ifdef LWIP_DEBUG
|
---|
1173 | , altcp_default_dbg_get_tcp_state
|
---|
1174 | #endif
|
---|
1175 | };
|
---|
1176 |
|
---|
1177 | #endif /* LWIP_ALTCP_TLS && LWIP_ALTCP_TLS_MBEDTLS */
|
---|
1178 | #endif /* LWIP_ALTCP */
|
---|