feat(pre_encrypted_ota): Added HTTPS server in pytest

1. Added the python based HTTPS server in pytest to start the https
server locally.
2. Updated the README.md file
3. Fixed some cosmetic changes in test_local_server_ota.c

esp_encrypted_img/examples/pre_encrypted_ota/README.md

@@ -52,6 +52,30 @@ idf.py build flash
 
 * An encrypted image is automatically generated by build system. Upload the generated encrypted image (`build/pre_encrypted_ota_secure.bin`) to a server for performing OTA update.
 
+### Configure and start python based HTTPS Server
+
+After a successful build, we need to create a self-signed certificate and run a simple HTTPS server as follows:
+
+![create_self_signed_certificate](https://raw.githubusercontent.com/espressif/idf-extra-components/master/esp_encrypted_img/examples/pre_encrypted_ota/docs/ota_self_signature.gif)
+
+* Create server_certs directory, Navigate to server_certs directory `cd server_certs`.
+* To create a new self-signed certificate and key, run the command `openssl req -x509 -newkey rsa:2048 -keyout ca_key.pem -out ca_cert.pem -days 365 -nodes`.
+  * When prompted for the `Common Name (CN)`, enter the name of the server that the "ESP-Dev-Board" will connect to. When running this example from a development machine, this is probably the IP address. The HTTPS client will check that the `CN` matches the address given in the HTTPS URL.
+
+You can start the server using following instructions:
+
+After the successful build, start the local python based HTTPS server using the certificate and key present in the 'server_certs' directory (certificate: ca_cert.pem and key: ca_key.pem).
+
+To start the server use the following command -
+```
+python pytest_pre_encrypted_ota.py build 8070 server_certs
+```
+
+1. build - build directory (where the new firmware image is present) will be exposed
+2. 8070 - server port (user can use any port)
+3. server_certs - cert directory where the certificate and key is present (here same ca_cert.pem is used in main/pre_encrypted_ota.c and server_certs dir). If user wants to use own certificate and key just pass the directory name, in which the certificate and key is present.
+
+* Note - If you don't want to create certificates then just run the `pytest_pre_encrypted_ota.py` without passing `server_certs` directory, the server will use the hardcoded certificates present in `pytest_pre_encrypted_ota.py`
 
 ## Configuration
 

esp_encrypted_img/examples/pre_encrypted_ota/main/tests/test_local_server_ota.c

@@ -145,13 +145,13 @@ static esp_err_t root_head_handler(httpd_req_t *req)
     return httpd_resp_send(req, NULL, binary_size); // No body for HEAD method
 }
 
-static const httpd_uri_t root = {
+static const httpd_uri_t get_root = {
     .uri       = "/",
     .method    = HTTP_GET,
     .handler   = root_get_handler
 };
 
-static const httpd_uri_t root1 = {
+static const httpd_uri_t head_root = {
     .uri       = "/",
     .method    = HTTP_HEAD,
     .handler   = root_head_handler
@@ -184,7 +184,7 @@ esp_err_t example_test_start_webserver(void)
 
     // Set URI handlers
     ESP_LOGI(TAG, "Registering URI handlers");
-    httpd_register_uri_handler(server, &root);
-    httpd_register_uri_handler(server, &root1);
+    httpd_register_uri_handler(server, &get_root);
+    httpd_register_uri_handler(server, &head_root);
     return ESP_OK;
 }

esp_encrypted_img/examples/pre_encrypted_ota/pytest_pre_encrypted_ota.py

@@ -3,8 +3,11 @@
 import http.server
 import multiprocessing
 import os
+import sys
+
 import socket
 import ssl
+from typing import Optional
 from typing import Callable
 
 import pexpect
@@ -17,6 +20,78 @@
 host_ip = '127.0.0.1'
 server_port = 443
 
+server_cert = '-----BEGIN CERTIFICATE-----\n'\
+             'MIIDKzCCAhOgAwIBAgIUBxM3WJf2bP12kAfqhmhhjZWv0ukwDQYJKoZIhvcNAQEL\n'\
+             'BQAwJTEjMCEGA1UEAwwaRVNQMzIgSFRUUFMgc2VydmVyIGV4YW1wbGUwHhcNMTgx\n'\
+             'MDE3MTEzMjU3WhcNMjgxMDE0MTEzMjU3WjAlMSMwIQYDVQQDDBpFU1AzMiBIVFRQ\n'\
+             'UyBzZXJ2ZXIgZXhhbXBsZTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEB\n'\
+             'ALBint6nP77RCQcmKgwPtTsGK0uClxg+LwKJ3WXuye3oqnnjqJCwMEneXzGdG09T\n'\
+             'sA0SyNPwrEgebLCH80an3gWU4pHDdqGHfJQa2jBL290e/5L5MB+6PTs2NKcojK/k\n'\
+             'qcZkn58MWXhDW1NpAnJtjVniK2Ksvr/YIYSbyD+JiEs0MGxEx+kOl9d7hRHJaIzd\n'\
+             'GF/vO2pl295v1qXekAlkgNMtYIVAjUy9CMpqaQBCQRL+BmPSJRkXBsYk8GPnieS4\n'\
+             'sUsp53DsNvCCtWDT6fd9D1v+BB6nDk/FCPKhtjYOwOAZlX4wWNSZpRNr5dfrxKsb\n'\
+             'jAn4PCuR2akdF4G8WLUeDWECAwEAAaNTMFEwHQYDVR0OBBYEFMnmdJKOEepXrHI/\n'\
+             'ivM6mVqJgAX8MB8GA1UdIwQYMBaAFMnmdJKOEepXrHI/ivM6mVqJgAX8MA8GA1Ud\n'\
+             'EwEB/wQFMAMBAf8wDQYJKoZIhvcNAQELBQADggEBADiXIGEkSsN0SLSfCF1VNWO3\n'\
+             'emBurfOcDq4EGEaxRKAU0814VEmU87btIDx80+z5Dbf+GGHCPrY7odIkxGNn0DJY\n'\
+             'W1WcF+DOcbiWoUN6DTkAML0SMnp8aGj9ffx3x+qoggT+vGdWVVA4pgwqZT7Ybntx\n'\
+             'bkzcNFW0sqmCv4IN1t4w6L0A87ZwsNwVpre/j6uyBw7s8YoJHDLRFT6g7qgn0tcN\n'\
+             'ZufhNISvgWCVJQy/SZjNBHSpnIdCUSJAeTY2mkM4sGxY0Widk8LnjydxZUSxC3Nl\n'\
+             'hb6pnMh3jRq4h0+5CZielA4/a+TdrNPv/qok67ot/XJdY3qHCCd8O2b14OVq9jo=\n'\
+             '-----END CERTIFICATE-----\n'
+
+server_key = '-----BEGIN PRIVATE KEY-----\n'\
+             'MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQCwYp7epz++0QkH\n'\
+             'JioMD7U7BitLgpcYPi8Cid1l7snt6Kp546iQsDBJ3l8xnRtPU7ANEsjT8KxIHmyw\n'\
+             'h/NGp94FlOKRw3ahh3yUGtowS9vdHv+S+TAfuj07NjSnKIyv5KnGZJ+fDFl4Q1tT\n'\
+             'aQJybY1Z4itirL6/2CGEm8g/iYhLNDBsRMfpDpfXe4URyWiM3Rhf7ztqZdveb9al\n'\
+             '3pAJZIDTLWCFQI1MvQjKamkAQkES/gZj0iUZFwbGJPBj54nkuLFLKedw7DbwgrVg\n'\
+             '0+n3fQ9b/gQepw5PxQjyobY2DsDgGZV+MFjUmaUTa+XX68SrG4wJ+DwrkdmpHReB\n'\
+             'vFi1Hg1hAgMBAAECggEAaTCnZkl/7qBjLexIryC/CBBJyaJ70W1kQ7NMYfniWwui\n'\
+             'f0aRxJgOdD81rjTvkINsPp+xPRQO6oOadjzdjImYEuQTqrJTEUnntbu924eh+2D9\n'\
+             'Mf2CAanj0mglRnscS9mmljZ0KzoGMX6Z/EhnuS40WiJTlWlH6MlQU/FDnwC6U34y\n'\
+             'JKy6/jGryfsx+kGU/NRvKSru6JYJWt5v7sOrymHWD62IT59h3blOiP8GMtYKeQlX\n'\
+             '49om9Mo1VTIFASY3lrxmexbY+6FG8YO+tfIe0tTAiGrkb9Pz6tYbaj9FjEWOv4Vc\n'\
+             '+3VMBUVdGJjgqvE8fx+/+mHo4Rg69BUPfPSrpEg7sQKBgQDlL85G04VZgrNZgOx6\n'\
+             'pTlCCl/NkfNb1OYa0BELqWINoWaWQHnm6lX8YjrUjwRpBF5s7mFhguFjUjp/NW6D\n'\
+             '0EEg5BmO0ePJ3dLKSeOA7gMo7y7kAcD/YGToqAaGljkBI+IAWK5Su5yldrECTQKG\n'\
+             'YnMKyQ1MWUfCYEwHtPvFvE5aPwKBgQDFBWXekpxHIvt/B41Cl/TftAzE7/f58JjV\n'\
+             'MFo/JCh9TDcH6N5TMTRS1/iQrv5M6kJSSrHnq8pqDXOwfHLwxetpk9tr937VRzoL\n'\
+             'CuG1Ar7c1AO6ujNnAEmUVC2DppL/ck5mRPWK/kgLwZSaNcZf8sydRgphsW1ogJin\n'\
+             '7g0nGbFwXwKBgQCPoZY07Pr1TeP4g8OwWTu5F6dSvdU2CAbtZthH5q98u1n/cAj1\n'\
+             'noak1Srpa3foGMTUn9CHu+5kwHPIpUPNeAZZBpq91uxa5pnkDMp3UrLIRJ2uZyr8\n'\
+             '4PxcknEEh8DR5hsM/IbDcrCJQglM19ZtQeW3LKkY4BsIxjDf45ymH407IQKBgE/g\n'\
+             'Ul6cPfOxQRlNLH4VMVgInSyyxWx1mODFy7DRrgCuh5kTVh+QUVBM8x9lcwAn8V9/\n'\
+             'nQT55wR8E603pznqY/jX0xvAqZE6YVPcw4kpZcwNwL1RhEl8GliikBlRzUL3SsW3\n'\
+             'q30AfqEViHPE3XpE66PPo6Hb1ymJCVr77iUuC3wtAoGBAIBrOGunv1qZMfqmwAY2\n'\
+             'lxlzRgxgSiaev0lTNxDzZkmU/u3dgdTwJ5DDANqPwJc6b8SGYTp9rQ0mbgVHnhIB\n'\
+             'jcJQBQkTfq6Z0H6OoTVi7dPs3ibQJFrtkoyvYAbyk36quBmNRjVh6rc8468bhXYr\n'\
+             'v/t+MeGJP/0Zw8v/X2CFll96\n'\
+             '-----END PRIVATE KEY-----\n'
+
+def start_https_server(ota_image_dir: str, server_ip: str, port: int, server_file: Optional[str] = None, key_file: Optional[str] = None) -> None:
+    os.chdir(ota_image_dir)
+
+    if server_file is None:
+        server_file = os.path.join(ota_image_dir, 'server_cert.pem')
+        cert_file_handle = open(server_file, 'w+')
+        cert_file_handle.write(server_cert)
+        cert_file_handle.close()
+
+    if key_file is None:
+        key_file = os.path.join(ota_image_dir, 'server_key.pem')
+        key_file_handle = open('server_key.pem', 'w+')
+        key_file_handle.write(server_key)
+        key_file_handle.close()
+
+    httpd = http.server.HTTPServer((server_ip, port), http.server.SimpleHTTPRequestHandler)
+
+    ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+    ssl_context.load_cert_chain(certfile=server_file, keyfile=key_file)
+
+    httpd.socket = ssl_context.wrap_socket(httpd.socket, server_side=True)
+    httpd.serve_forever()
+
 @pytest.mark.generic
 def test_examples_protocol_pre_encrypted_ota_example(dut: Dut) -> None:
     bin_path = os.path.join(dut.app.binary_path, enc_bin_name)
@@ -36,3 +111,20 @@ def test_examples_protocol_pre_encrypted_ota_example(dut: Dut) -> None:
     finally:
         pass
 
+if __name__ == '__main__':
+    if sys.argv[2:]: # if two or more arguments are provided
+        # Usage: python pytest_pre_encrypted_ota.py <image_dir> <server_port> <cert_dir>
+        this_dir = os.path.dirname(os.path.realpath(__file__))
+        bin_dir = os.path.join(this_dir, sys.argv[1])
+        port = int(sys.argv[2])
+        cert_dir = bin_dir if not sys.argv[3:] else os.path.join(this_dir, sys.argv[3])  # optional argument
+        print(f'Starting HTTPS server at "https://0.0.0.0:{port}"')
+        server_file=os.path.join(cert_dir, 'ca_cert.pem')
+        key_file=os.path.join(cert_dir, 'ca_key.pem')
+        #check if file exits
+        if not os.path.exists(server_file):
+            server_file = None
+        if not os.path.exists(key_file):
+            key_file = None
+
+        start_https_server(bin_dir, '', port, server_file, key_file)