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Earle F. Philhower, III e3c970210f
Add BearSSL client and server, support true bidir, lower memory, modern SSL (#4273)
BearSSL (https://www.bearssl.org) is a TLS(SSL) library written by
Thomas Pornin that is optimized for lower-memory embedded systems
like the ESP8266. It supports a wide variety of modern ciphers and
is unique in that it doesn't perform any memory allocations during
operation (which is the unfortunate bane of the current axTLS).

BearSSL is also absolutely focused on security and by default performs
all its security checks on x.509 certificates during the connection
phase (but if you want to be insecure and dangerous, that's possible
too).

While it does support unidirectional SSL buffers, like axTLS,
as implemented the ESP8266 wrappers only support bidirectional
buffers. These bidirectional buffers avoid deadlocks in protocols
which don't have well separated receive and transmit periods.

This patch adds several classes which allow connecting to TLS servers
using this library in almost the same way as axTLS:
BearSSL::WiFiClientSecure - WiFiClient that supports TLS
BearSSL::WiFiServerSecure - WiFiServer supporting TLS and client certs

It also introduces objects for PEM/DER encoded keys and certificates:
BearSSLX509List - x.509 Certificate (list) for general use
BearSSLPrivateKey - RSA or EC private key
BearSSLPublicKey - RSA or EC public key (i.e. from a public website)

Finally, it adds a Certificate Authority store object which lets
BearSSL access a set of trusted CA certificates on SPIFFS to allow it
to verify the identity of any remote site on the Internet, without
requiring RAM except for the single matching certificate.
CertStoreSPIFFSBearSSL - Certificate store utility

Client certificates are supported for the BearSSL::WiFiClientSecure, and
what's more the BearSSL::WiFiServerSecure can also *require* remote clients
to have a trusted certificate signed by a specific CA (or yourself with
self-signing CAs).

Maximum Fragment Length Negotiation probing and usage are supported, but
be aware that most sites on the Internet don't support it yet.  When
available, you can reduce the memory footprint of the SSL client or server
dramatically (i.e. down to 2-8KB vs. the ~22KB required for a full 16K
receive fragment and 512b send fragment).  You can also manually set a
smaller fragment size and guarantee at your protocol level all data will
fit within it.

Examples are included to show the usage of these new features.

axTLS has been moved to its own namespace, "axtls".  A default "using"
clause allows existing apps to run using axTLS without any changes.

The BearSSL::WiFi{client,server}Secure implements the axTLS
client/server API which lets many end user applications take advantage
of BearSSL with few or no changes.

The BearSSL static library used presently is stored at
https://github.com/earlephilhower/bearssl-esp8266 and can be built
using the standard ESP8266 toolchain.
2018-05-14 20:46:47 -07:00

178 lines
6.5 KiB
C++

/*
Demonstrate the usage of WiFiServerBearSSL.
By Earle F. Philhower, III
A simple HTTPS server is implemented with a self-signed
certificate for the ESP8266.
This is NOT the best way to implement a HTTPS website on the
ESP8266. Please see the ESP8266WebServerBearSSL example for
a much better way of doing this!
IMPORTANT NOTES ABOUT SSL CERTIFICATES
1. USE/GENERATE YOUR OWN CERTIFICATES
While a sample, self-signed certificate is included in this example,
it is ABSOLUTELY VITAL that you use your own SSL certificate in any
real-world deployment. Anyone with the certificate and key may be
able to decrypt your traffic, so your own keys should be kept in a
safe manner, not accessible on any public network.
2. HOW TO GENERATE YOUR OWN CERTIFICATE/KEY PAIR
It is easy to use OpenSSL to generate a self-signed certificate
openssl req -x509 -nodes -newkey rsa:2048 -keyout key.pem -out cert.pem -days 4096
You may also, of course, use a commercial, trusted SSL provider to
generate your certificate.
Included with this example are *SAMPLE* certs and keys. They are NOT
SECURE, since they're shared with all copies of the repo, so
DO NOT USE THE SAMPLE CERTS, KEYS, OR CAS IN YOUR OWN PROJECT!!!
Run this example and then try connecting to the server https://IP.
This example is released into the public domain.
*/
#include <ESP8266WiFi.h>
#include <time.h>
const char *ssid = "....";
const char *pass = "....";
// The HTTPS server
BearSSL::WiFiServerSecure server(443);
// The server's private key which must be kept secret
const char server_private_key[] PROGMEM = R"EOF(
-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----
)EOF";
// The server's public certificate which must be shared
const char server_cert[] PROGMEM = R"EOF(
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
)EOF";
void setup() {
Serial.begin(115200);
Serial.println();
Serial.println();
// We start by connecting to a WiFi network
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, pass);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
// Attach the server private cert/key combo
BearSSLX509List *serverCertList = new BearSSLX509List(server_cert);
BearSSLPrivateKey *serverPrivKey = new BearSSLPrivateKey(server_private_key);
server.setRSACert(serverCertList, serverPrivKey);
// Actually start accepting connections
server.begin();
}
static const char *HTTP_RES =
"HTTP/1.0 200 OK\r\n"
"Connection: close\r\n"
"Content-Length: 62\r\n"
"Content-Type: text/html; charset=iso-8859-1\r\n"
"\r\n"
"<html>\r\n"
"<body>\r\n"
"<p>Hello from ESP8266!</p>\r\n"
"</body>\r\n"
"</html>\r\n";
void loop() {
BearSSL::WiFiClientSecure incoming = server.available();
if (!incoming) {
return;
}
Serial.println("Incoming connection...\n");
// Ugly way to wait for \r\n (i.e. end of HTTP request which we don't actually parse here)
uint32_t timeout=millis() + 1000;
int lcwn = 0;
for (;;) {
unsigned char x=0;
if ((millis() > timeout) || (incoming.available() && incoming.read(&x, 1) < 0)) {
incoming.stop();
Serial.printf("Connection error, closed\n");
return;
} else if (!x) {
yield();
continue;
} else if (x == 0x0D) {
continue;
} else if (x == 0x0A) {
if (lcwn) {
break;
}
lcwn = 1;
} else
lcwn = 0;
}
incoming.write((uint8_t*)HTTP_RES, strlen(HTTP_RES));
incoming.flush();
incoming.stop();
Serial.printf("Connection closed.\n");
}