Hi,
I am trying to make an HTTPS request using an ESP32 development board.
- I am using the HTTPClient library to make the request.
- I have an API token for this request.
- The documentation of the server I am trying to query states that the API key should be included as a header in all requests in the following format.
auth-token: myapitoken
What code am I using? Full code is uploaded below. I have used the library example "BasicHttpsClient" and added the following line.
https.addHeader("Authorization", "auth_token: uJU7AL0FbiGW9TgMt8lHOu8cLs31eFgZ");
What error am I getting? The code returns the error "connection refused".
[HTTPS] GET... failed, error: connection refused.
Steps that I have tested:
- I have confirmed that my API token is valid by sending the request using curl in my computer shell. I can then access the data as intended. See screenshot below.
- I have tested changing the URL for a resource that do not not require authentification: https://api.electricitymap.org/v3/zones. I confirmed that the code then worked as intended.
- I don't quite understand how the HTTPClient library work. have tested the following different syntaxes for the addHeader method with no success.
https.addHeader("Authorization", "auth_token: uJU7AL0FbiGW9TgMt8lHOu8cLs31eFgZ"); //alternative 1
https.addHeader("auth_token", "uJU7AL0FbiGW9TgMt8lHOu8cLs31eFgZ"); //alternative 2
https.addHeader("Authorization", "uJU7AL0FbiGW9TgMt8lHOu8cLs31eFgZ"); //alternative 3
Full code below
#include <Arduino.h>
#include <WiFi.h>
#include <WiFiMulti.h>
#include <HTTPClient.h>
#include <WiFiClientSecure.h>
const char* ssid = "My wifi ssid";
const char* password = "My password";
const char* server = "api.electricitymap.org"; // Server URL
const char* rootCACertificate= \
"-----BEGIN CERTIFICATE-----\n" \
"MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw\n" \
"TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh\n" \
"cmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMTUwNjA0MTEwNDM4\n" \
"WhcNMzUwNjA0MTEwNDM4WjBPMQswCQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJu\n" \
"ZXQgU2VjdXJpdHkgUmVzZWFyY2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBY\n" \
"MTCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIBAK3oJHP0FDfzm54rVygc\n" \
"h77ct984kIxuPOZXoHj3dcKi/vVqbvYATyjb3miGbESTtrFj/RQSa78f0uoxmyF+\n" \
"0TM8ukj13Xnfs7j/EvEhmkvBioZxaUpmZmyPfjxwv60pIgbz5MDmgK7iS4+3mX6U\n" \
"A5/TR5d8mUgjU+g4rk8Kb4Mu0UlXjIB0ttov0DiNewNwIRt18jA8+o+u3dpjq+sW\n" \
"T8KOEUt+zwvo/7V3LvSye0rgTBIlDHCNAymg4VMk7BPZ7hm/ELNKjD+Jo2FR3qyH\n" \
"B5T0Y3HsLuJvW5iB4YlcNHlsdu87kGJ55tukmi8mxdAQ4Q7e2RCOFvu396j3x+UC\n" \
"B5iPNgiV5+I3lg02dZ77DnKxHZu8A/lJBdiB3QW0KtZB6awBdpUKD9jf1b0SHzUv\n" \
"KBds0pjBqAlkd25HN7rOrFleaJ1/ctaJxQZBKT5ZPt0m9STJEadao0xAH0ahmbWn\n" \
"OlFuhjuefXKnEgV4We0+UXgVCwOPjdAvBbI+e0ocS3MFEvzG6uBQE3xDk3SzynTn\n" \
"jh8BCNAw1FtxNrQHusEwMFxIt4I7mKZ9YIqioymCzLq9gwQbooMDQaHWBfEbwrbw\n" \
"qHyGO0aoSCqI3Haadr8faqU9GY/rOPNk3sgrDQoo//fb4hVC1CLQJ13hef4Y53CI\n" \
"rU7m2Ys6xt0nUW7/vGT1M0NPAgMBAAGjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNV\n" \
"HRMBAf8EBTADAQH/MB0GA1UdDgQWBBR5tFnme7bl5AFzgAiIyBpY9umbbjANBgkq\n" \
"hkiG9w0BAQsFAAOCAgEAVR9YqbyyqFDQDLHYGmkgJykIrGF1XIpu+ILlaS/V9lZL\n" \
"ubhzEFnTIZd+50xx+7LSYK05qAvqFyFWhfFQDlnrzuBZ6brJFe+GnY+EgPbk6ZGQ\n" \
"3BebYhtF8GaV0nxvwuo77x/Py9auJ/GpsMiu/X1+mvoiBOv/2X/qkSsisRcOj/KK\n" \
"NFtY2PwByVS5uCbMiogziUwthDyC3+6WVwW6LLv3xLfHTjuCvjHIInNzktHCgKQ5\n" \
"ORAzI4JMPJ+GslWYHb4phowim57iaztXOoJwTdwJx4nLCgdNbOhdjsnvzqvHu7Ur\n" \
"TkXWStAmzOVyyghqpZXjFaH3pO3JLF+l+/+sKAIuvtd7u+Nxe5AW0wdeRlN8NwdC\n" \
"jNPElpzVmbUq4JUagEiuTDkHzsxHpFKVK7q4+63SM1N95R1NbdWhscdCb+ZAJzVc\n" \
"oyi3B43njTOQ5yOf+1CceWxG1bQVs5ZufpsMljq4Ui0/1lvh+wjChP4kqKOJ2qxq\n" \
"4RgqsahDYVvTH9w7jXbyLeiNdd8XM2w9U/t7y0Ff/9yi0GE44Za4rF2LN9d11TPA\n" \
"mRGunUHBcnWEvgJBQl9nJEiU0Zsnvgc/ubhPgXRR4Xq37Z0j4r7g1SgEEzwxA57d\n" \
"emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc=\n" \
"-----END CERTIFICATE-----\n";
void setClock() {
configTime(0, 0, "pool.ntp.org");
Serial.print(F("Waiting for NTP time sync: "));
time_t nowSecs = time(nullptr);
while (nowSecs < 8 * 3600 * 2) {
delay(500);
Serial.print(F("."));
yield();
nowSecs = time(nullptr);
}
Serial.println();
struct tm timeinfo;
gmtime_r(&nowSecs, &timeinfo);
Serial.print(F("Current time: "));
Serial.print(asctime(&timeinfo));
}
WiFiMulti WiFiMulti;
void setup() {
Serial.begin(115200);
// Serial.setDebugOutput(true);
Serial.println();
Serial.println();
Serial.println();
WiFi.mode(WIFI_STA);
WiFiMulti.addAP(ssid, password);
// wait for WiFi connection
Serial.print("Waiting for WiFi to connect...");
while ((WiFiMulti.run() != WL_CONNECTED)) {
Serial.print(".");
}
Serial.println(" connected");
setClock();
}
void loop() {
WiFiClientSecure *client = new WiFiClientSecure;
if(client) {
client -> setCACert(rootCACertificate);
{
// Add a scoping block for HTTPClient https to make sure it is destroyed before WiFiClientSecure *client is
HTTPClient https;
Serial.print("[HTTPS] begin...\n");
if (https.begin(*client, "https://api-access.electricitymaps.com/2w97h07rvxvuaa1g/carbon-intensity/latest?zone=NL")) { // HTTPS //https://api.electricitymap.org/v3/zones
Serial.print("[HTTPS] GET...\n");
// start connection and send HTTP header
https.addHeader("Authorization", "auth-token: uJU7AL0FbiGW9TgMt8lHOu8cLs31eFgZ");
int httpCode = https.GET();
// httpCode will be negative on error
if (httpCode > 0) {
// HTTP header has been send and Server response header has been handled
Serial.printf("[HTTPS] GET... code: %d\n", httpCode);
// file found at server
if (httpCode == HTTP_CODE_OK || httpCode == HTTP_CODE_MOVED_PERMANENTLY) {
String payload = https.getString();
Serial.println(payload);
}
} else {
Serial.printf("[HTTPS] GET... failed, error: %s\n", https.errorToString(httpCode).c_str());
}
https.end();
} else {
Serial.printf("[HTTPS] Unable to connect\n");
}
// End extra scoping block
}
delete client;
} else {
Serial.println("Unable to create client");
}
Serial.println();
Serial.println("Waiting 10s before the next round...");
delay(10000);
}
Screenshot from request done from shell:
