lwip/contrib/examples/httpd/https_example/https_example.c
2019-08-06 22:34:17 +02:00

145 lines
4.9 KiB
C

/**
* @file
* HTTPD https example
*
* This file demonstrates how to initialize httpd for https.
* To do this, it needs 2 files:
* - server certificate
* - server private key
*
* In addition to that, watch out for resource shortage. You'll need plenty of
* heap (start with MEM_SIZE >= 200 KByte or monitor its err counters) and be
* sure to at least set the following settings high enough (monitor
* lwip_stats for an idea of what's needed):
* - MEMP_NUM_TCP_PCB/MEMP_NUM_ALTCP_PCB
* - MEMP_NUM_TCPIP_MSG_INPKT
* - MEMP_NUM_TCP_SEG
*/
/*
* Copyright (c) 2017-2019 Simon Goldschmidt
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Simon Goldschmidt <goldsimon@gmx.de>
*
*/
#include "lwip/opt.h"
#include "https_example.h"
#include "lwip/altcp_tls.h"
#include "lwip/apps/httpd.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/** define LWIP_HTTPD_EXAMPLE_HTTPS to 1 to enable this file system */
#ifndef LWIP_HTTPD_EXAMPLE_HTTPS
#define LWIP_HTTPD_EXAMPLE_HTTPS 0
#endif
#if LWIP_HTTPD_EXAMPLE_HTTPS && LWIP_ALTCP_TLS
#ifndef LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE
#error "define LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE to the created server private key"
#endif
/* If the key file is password-protected, define LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE_PASS */
#ifdef LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE_PASS
#ifndef LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE_PASS_LEN
#define LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE_PASS_LEN strlen(LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE_PASS)
#endif
#else
#define LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE_PASS NULL
#define LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE_PASS_LEN 0
#endif
#ifndef LWIP_HTTPD_EXAMPLE_HTTPS_CERT_FILE
#error "define LWIP_HTTPD_EXAMPLE_HTTPS_CERT_FILE to the created server certificate"
#endif
static u8_t *read_file(const char *filename, size_t *file_size)
{
u8_t *buf;
long fsize;
FILE *f = fopen(filename, "rb");
if (!f) {
return NULL;
}
fseek(f, 0, SEEK_END);
fsize = ftell(f);
fseek(f, 0, SEEK_SET);
buf = (u8_t *)malloc(fsize + 1);
if (!buf) {
fclose(f);
return NULL;
}
fread(buf, 1, fsize, f);
fclose(f);
buf[fsize] = 0;
if (file_size) {
/* Note: the '+ 1' is required for mbedTLS to correctly parse the buffer */
*file_size = (size_t)(fsize + 1);
}
return buf;
}
/** This function loads a server certificate and private key as x509 from disk.
* For information how to create such files, see mbedTLS tutorial ("How to
* generate a self-signed certificate") or OpenSSL documentation ("How to
* generate a self-signed certificate and private key using OpenSSL"), e.g.
* 'openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout privateKey.key -out certificate.crt'
* Copy the resulting files and define the path to them
*/
void
https_ex_init(void)
{
struct altcp_tls_config *conf;
u8_t *privkey, *cert;
size_t privkey_size, cert_size;
privkey = read_file(LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE, &privkey_size);
LWIP_ASSERT("Failed to open https server private key", privkey != NULL);
cert = read_file(LWIP_HTTPD_EXAMPLE_HTTPS_CERT_FILE, &cert_size);
LWIP_ASSERT("Failed to open https server certificate", cert != NULL);
conf = altcp_tls_create_config_server_privkey_cert(privkey, privkey_size,
LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE_PASS, LWIP_HTTPD_EXAMPLE_HTTPS_KEY_FILE_PASS_LEN, cert, cert_size);
LWIP_ASSERT("Failed to create https server config", conf != NULL);
httpd_inits(conf);
/* secure erase should be done in production environment */
free(privkey);
free(cert);
}
#endif /* LWIP_HTTPD_EXAMPLE_HTTPS */