From 23eb8d5bce2a178ebcfb574e1bc0ffbd70acda19 Mon Sep 17 00:00:00 2001
From: Eggert Jung <eggert.s.jung@wischhof13.de>
Date: Thu, 7 Dec 2023 04:05:33 +0100
Subject: [PATCH] add https from example

---
 main/https.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 main/https.h |   1 +
 2 files changed, 109 insertions(+)
 create mode 100644 main/https.c
 create mode 100644 main/https.h

diff --git a/main/https.c b/main/https.c
new file mode 100644
index 0000000..0288827
--- /dev/null
+++ b/main/https.c
@@ -0,0 +1,108 @@
+#include "esp_tls.h"
+#include "esp_log.h"
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+
+#include "esp_crt_bundle.h"
+
+static const char *TAG = "https";
+
+static void https_get_request(esp_tls_cfg_t cfg, const char *WEB_SERVER_URL, const char *REQUEST)
+{
+    char buf[512];
+    int ret, len;
+
+    esp_tls_t *tls = esp_tls_init();
+    if (!tls) {
+        ESP_LOGE(TAG, "Failed to allocate esp_tls handle!");
+        goto exit;
+    }
+
+    if (esp_tls_conn_http_new_sync(WEB_SERVER_URL, &cfg, tls) == 1) {
+        ESP_LOGI(TAG, "Connection established...");
+    } else {
+        ESP_LOGE(TAG, "Connection failed...");
+        int esp_tls_code = 0, esp_tls_flags = 0;
+        esp_tls_error_handle_t tls_e = NULL;
+        esp_tls_get_error_handle(tls, &tls_e);
+        /* Try to get TLS stack level error and certificate failure flags, if any */
+        ret = esp_tls_get_and_clear_last_error(tls_e, &esp_tls_code, &esp_tls_flags);
+        if (ret == ESP_OK) {
+            ESP_LOGE(TAG, "TLS error = -0x%x, TLS flags = -0x%x", esp_tls_code, esp_tls_flags);
+        }
+        goto cleanup;
+    }
+
+#ifdef CONFIG_EXAMPLE_CLIENT_SESSION_TICKETS
+    /* The TLS session is successfully established, now saving the session ctx for reuse */
+    if (save_client_session) {
+        esp_tls_free_client_session(tls_client_session);
+        tls_client_session = esp_tls_get_client_session(tls);
+    }
+#endif
+
+    size_t written_bytes = 0;
+    do {
+        ret = esp_tls_conn_write(tls,
+                                 REQUEST + written_bytes,
+                                 strlen(REQUEST) - written_bytes);
+        if (ret >= 0) {
+            ESP_LOGI(TAG, "%d bytes written", ret);
+            written_bytes += ret;
+        } else if (ret != ESP_TLS_ERR_SSL_WANT_READ  && ret != ESP_TLS_ERR_SSL_WANT_WRITE) {
+            ESP_LOGE(TAG, "esp_tls_conn_write  returned: [0x%02X](%s)", ret, esp_err_to_name(ret));
+            goto cleanup;
+        }
+    } while (written_bytes < strlen(REQUEST));
+
+    ESP_LOGI(TAG, "Reading HTTP response...");
+    do {
+        len = sizeof(buf) - 1;
+        memset(buf, 0x00, sizeof(buf));
+        ret = esp_tls_conn_read(tls, (char *)buf, len);
+
+        if (ret == ESP_TLS_ERR_SSL_WANT_WRITE  || ret == ESP_TLS_ERR_SSL_WANT_READ) {
+            continue;
+        } else if (ret < 0) {
+            ESP_LOGE(TAG, "esp_tls_conn_read  returned [-0x%02X](%s)", -ret, esp_err_to_name(ret));
+            break;
+        } else if (ret == 0) {
+            ESP_LOGI(TAG, "connection closed");
+            break;
+        }
+
+        len = ret;
+        ESP_LOGD(TAG, "%d bytes read", len);
+        /* Print response directly to stdout as it is read */
+        for (int i = 0; i < len; i++) {
+            putchar(buf[i]);
+        }
+        putchar('\n'); // JSON output doesn't have a newline at end
+    } while (1);
+
+cleanup:
+    esp_tls_conn_destroy(tls);
+exit:
+    for (int countdown = 10; countdown >= 0; countdown--) {
+        ESP_LOGI(TAG, "%d...", countdown);
+        vTaskDelay(1000 / portTICK_PERIOD_MS);
+    }
+}
+
+#define WEB_SERVER "www.howsmyssl.com"
+#define WEB_PORT "443"
+#define WEB_URL "https://www.howsmyssl.com/a/check"
+
+static const char HOWSMYSSL_REQUEST[] = "GET " WEB_URL " HTTP/1.1\r\n"
+                             "Host: "WEB_SERVER"\r\n"
+                             "User-Agent: esp-idf/1.0 esp32\r\n"
+                             "\r\n";
+
+void https_get_request_using_crt_bundle(void)
+{
+    ESP_LOGI(TAG, "https_request using crt bundle");
+    esp_tls_cfg_t cfg = {
+        .crt_bundle_attach = esp_crt_bundle_attach,
+    };
+    https_get_request(cfg, WEB_URL, HOWSMYSSL_REQUEST);
+}
diff --git a/main/https.h b/main/https.h
new file mode 100644
index 0000000..0fe1a4c
--- /dev/null
+++ b/main/https.h
@@ -0,0 +1 @@
+void https_get_request_using_crt_bundle(void);