Merge pull request #110 from abachman/abachman-update-IO-tls-fingerprint

update IO TLS fingerprint

Author: ladyada

examples/adafruitio_secure_esp8266/adafruitio_secure_esp8266.ino

@@ -40,8 +40,9 @@ WiFiClientSecure client;
 // Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.
 Adafruit_MQTT_Client mqtt(&client, AIO_SERVER, AIO_SERVERPORT, AIO_USERNAME, AIO_KEY);
 
-// io.adafruit.com SHA1 fingerprint
-const char* fingerprint = "AD 4B 64 B3 67 40 B5 FC 0E 51 9B BD 25 E9 7F 88 B6 2A A3 5B";
+// io.adafruit.com SHA1 fingerprint. Current fingerprint can be verified via: 
+//   echo | openssl s_client -connect io.adafruit.com:443 |& openssl x509 -fingerprint -noout
+#define AIO_SSL_FINGERPRINT "77 00 54 2D DA E7 D8 03 27 31 23 99 EB 27 DB CB A5 4C 57 18"
 
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