Appliquer la notion
L'objectif de l'exercice va être de trouver les certificats inclus dans votre navigateur, et comprendre comment le site "librecours.net" peut proposer du HTTPS à votre navigateur. On utilisera ici Firefox.
Question
Dans Firefox, trouvez les certificats qui sont dits "de confiance".
Indice
Ça se passe dans l'onglet Vie privée et sécurité des Préférences
Indice
On peut écrire about:preferences dans la barre d'adresse puis choisir le menu vie privée et sécurité.
Indice
On peut aussi écrire directement about:preferences#privacy dans la barre d'adresse.
Solution
La section sécurité propose d'afficher les certificats.
Ce qui ouvre une fenêtre avec la liste de tous les certificats intégrés dans le navigateur.
Question
En vous rendant sur le site https://librecours.net identifiez la chaîne de confiance du certificat.
Indice
Pour accéder au certificat d'un site web, cliquer sur le cadenas dans la barre d'adresse.
Solution
librecours.net → Let's Encrypt → Internet Security Research Group
Complément :
Vous pouvez lire le certificat du site directement en entrant l'adresse suivante dans votre navigateur Firefox
1
about:certificate?cert=MIIEdDCCA1ygAwIBAgISBD0fp4fOUBcJOYSRuwevPppZMA0GCSqGSIb3DQEBCwUAMDIxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MQswCQYDVQQDEwJSMzAeFw0yMTA1MDUxMzA0NTRaFw0yMTA4MDMxMzA0NTRaMBkxFzAVBgNVBAMTDmxpYnJlY291cnMubmV0MHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEWLY%2BQJXhCnV5tf9n%2FOzQIJInmf46YsUm%2B%2B%2B1YGBf69QUuHj5siZNEcLevWeqsImQ2GRGiphcwI6mWSBX5SpRXX9DBvmrmcQylyfa9uPVF6oV2gBDCZhN67zU74W9j7kUo4ICSTCCAkUwDgYDVR0PAQH%2FBAQDAgeAMB0GA1UdJQQWMBQGCCsGAQUFBwMBBggrBgEFBQcDAjAMBgNVHRMBAf8EAjAAMB0GA1UdDgQWBBTjW3%2FkjIKsidx6eROh5lJGOdlKmjAfBgNVHSMEGDAWgBQULrMXt1hWy65QCUDmH6%2BdixTCxjBVBggrBgEFBQcBAQRJMEcwIQYIKwYBBQUHMAGGFWh0dHA6Ly9yMy5vLmxlbmNyLm9yZzAiBggrBgEFBQcwAoYWaHR0cDovL3IzLmkubGVuY3Iub3JnLzAZBgNVHREEEjAQgg5saWJyZWNvdXJzLm5ldDBMBgNVHSAERTBDMAgGBmeBDAECATA3BgsrBgEEAYLfEwEBATAoMCYGCCsGAQUFBwIBFhpodHRwOi8vY3BzLmxldHNlbmNyeXB0Lm9yZzCCAQQGCisGAQQB1nkCBAIEgfUEgfIA8AB2AJQgvB6O1Y1siHMfgosiLA3R2k1ebE%2BUPWHbTi9YTaLCAAABeTzYiJAAAAQDAEcwRQIhAMFimwZzlKKOO0P24CIWbM2WyEgwXpJQjmksJT61eJkCAiAqoi9dDPnL3Oq8SMeYVzM5Hf6zVzZ1HuHY0c5pbCMh1wB2AH0%2B8viP%2F4hVaCTCwMqeUol5K8UOeAl%2FLmqXaJl%2BIvDXAAABeTzYiLYAAAQDAEcwRQIhANY0%2BIq9robikbwzQ3VNgPT0uRN6dfjEQeyLtptN7hHQAiBznuuofCPbkS2umE%2FnKTJV9biIAxWsd2YNAZ9R9%2Bf3ZjANBgkqhkiG9w0BAQsFAAOCAQEAtLuzrMlvkN3d3IflMgYqd%2Fe47GUP%2F%2FhPRh1mEmq%2F3mughW1F86qsrC71AK16Ynq2fGJUZ1vjmUbk97r0iz1BxyIp%2Bfscj9leRwlrLDr2NI4ekPlTMMYyarw5smVd2P13EquwHyC5wfWNUkLb%2B9TkooSUuESlRcBIUCjK4T0zBedOBGQw3DiDxnfclv%2Fy0JWNxQlaNRiMiEG6xdq5CnaXZQrd%2BM4HgP7eZtuRFwnHtQr06kXPRlnFKBoVQS0VaJGckd4Acegz3ArDaSeFiOw%2BGIgippbOv%2B2sZlXu3CkFfLEyJiUV2BpWuukuy6YWvneoO2pdHVwCb7mLwUKAauMg%2Bw%3D%3D&cert=MIIFFjCCAv6gAwIBAgIRAJErCErPDBinU%2FbWLiWnX1owDQYJKoZIhvcNAQELBQAwTzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2VhcmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMjAwOTA0MDAwMDAwWhcNMjUwOTE1MTYwMDAwWjAyMQswCQYDVQQGEwJVUzEWMBQGA1UEChMNTGV0J3MgRW5jcnlwdDELMAkGA1UEAxMCUjMwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQC7AhUozPaglNMPEuyNVZLD%2BILxmaZ6QoinXSaqtSu5xUyxr45r%2BXXIo9cPR5QUVTVXjJ6oojkZ9YI8QqlObvU7wy7bjcCwXPNZOOftz2nwWgsbvsCUJCWH%2BjdxsxPnHKzhm%2B%2Fb5DtFUkWWqcFTzjTIUu61ru2P3mBw4qVUq7ZtDpelQDRrK9O8ZutmNHz6a4uPVymZ%2BDAXXbpyb%2FuBxa3Shlg9F8fnCbvxK%2FeG3MHacV3URuPMrSXBiLxgZ3Vms%2FEY96Jc5lP%2FOoi2R6X%2FExjqmAl3P51T%2Bc8B5fWmcBcUr2Ok%2F5mzk53cU6cG%2FkiFHaFpriV1uxPMUgP17VGhi9sVAgMBAAGjggEIMIIBBDAOBgNVHQ8BAf8EBAMCAYYwHQYDVR0lBBYwFAYIKwYBBQUHAwIGCCsGAQUFBwMBMBIGA1UdEwEB%2FwQIMAYBAf8CAQAwHQYDVR0OBBYEFBQusxe3WFbLrlAJQOYfr52LFMLGMB8GA1UdIwQYMBaAFHm0WeZ7tuXkAXOACIjIGlj26ZtuMDIGCCsGAQUFBwEBBCYwJDAiBggrBgEFBQcwAoYWaHR0cDovL3gxLmkubGVuY3Iub3JnLzAnBgNVHR8EIDAeMBygGqAYhhZodHRwOi8veDEuYy5sZW5jci5vcmcvMCIGA1UdIAQbMBkwCAYGZ4EMAQIBMA0GCysGAQQBgt8TAQEBMA0GCSqGSIb3DQEBCwUAA4ICAQCFyk5HPqP3hUSFvNVneLKYY611TR6WPTNlclQtgaDqw%2B34IL9fzLdwALduO%2FZelN7kIJ%2Bm74uyA%2BeitRY8kc607TkC53wlikfmZW4%2FRvTZ8M6UK%2B5UzhK8jCdLuMGYL6KvzXGRSgi3yLgjewQtCPkIVz6D2QQzCkcheAmCJ8MqyJu5zlzyZMjAvnnAT45tRAxekrsu94sQ4egdRCnbWSDtY7kh%2BBImlJNXoB1lBMEKIq4QDUOXoRgffuDghje1WrG9ML%2BHbisq%2FyFOGwXD9RiX8F6sw6W4avAuvDszue5L3sz85K%2BEC4Y%2FwFVDNvZo4TYXao6Z0f%2BlQKc0t8DQYzk1OXVu8rp2yJMC6alLbBfODALZvYH7n7do1AZls4I9d1P4jnkDrQoxB3UqQ9hVl3LEKQ73xF1OyK5GhDDX8oVfGKF5u%2BdecIsH4YaTw7mP3GFxJSqv3%2B0lUFJoi5Lc5da149p90IdshCExroL1%2B7mryIkXPeFM5TgO9r0rvZaBFOvV2z0gp35Z0%2BL4WPlbuEjN%2FlxPFin%2BHlUjr8gRsI3qfJOQFy%2F9rKIJR0Y%2F8Omwt%2F8oTWgy1mdeHmmjk7j1nYsvC9JSQ6ZvMldlTTKB3zhThV1%2BXWYp6rjd5JW1zbVWEkLNxE7GJThEUG3szgBVGP7pSWTUTsqXnLRbwHOoq7hHwg%3D%3D&cert=MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAwTzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2VhcmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMTUwNjA0MTEwNDM4WhcNMzUwNjA0MTEwNDM4WjBPMQswCQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJuZXQgU2VjdXJpdHkgUmVzZWFyY2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBYMTCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIBAK3oJHP0FDfzm54rVygch77ct984kIxuPOZXoHj3dcKi%2FvVqbvYATyjb3miGbESTtrFj%2FRQSa78f0uoxmyF%2B0TM8ukj13Xnfs7j%2FEvEhmkvBioZxaUpmZmyPfjxwv60pIgbz5MDmgK7iS4%2B3mX6UA5%2FTR5d8mUgjU%2Bg4rk8Kb4Mu0UlXjIB0ttov0DiNewNwIRt18jA8%2Bo%2Bu3dpjq%2BsWT8KOEUt%2Bzwvo%2F7V3LvSye0rgTBIlDHCNAymg4VMk7BPZ7hm%2FELNKjD%2BJo2FR3qyHB5T0Y3HsLuJvW5iB4YlcNHlsdu87kGJ55tukmi8mxdAQ4Q7e2RCOFvu396j3x%2BUCB5iPNgiV5%2BI3lg02dZ77DnKxHZu8A%2FlJBdiB3QW0KtZB6awBdpUKD9jf1b0SHzUvKBds0pjBqAlkd25HN7rOrFleaJ1%2FctaJxQZBKT5ZPt0m9STJEadao0xAH0ahmbWnOlFuhjuefXKnEgV4We0%2BUXgVCwOPjdAvBbI%2Be0ocS3MFEvzG6uBQE3xDk3SzynTnjh8BCNAw1FtxNrQHusEwMFxIt4I7mKZ9YIqioymCzLq9gwQbooMDQaHWBfEbwrbwqHyGO0aoSCqI3Haadr8faqU9GY%2FrOPNk3sgrDQoo%2F%2Ffb4hVC1CLQJ13hef4Y53CIrU7m2Ys6xt0nUW7%2FvGT1M0NPAgMBAAGjQjBAMA4GA1UdDwEB%2FwQEAwIBBjAPBgNVHRMBAf8EBTADAQH%2FMB0GA1UdDgQWBBR5tFnme7bl5AFzgAiIyBpY9umbbjANBgkqhkiG9w0BAQsFAAOCAgEAVR9YqbyyqFDQDLHYGmkgJykIrGF1XIpu%2BILlaS%2FV9lZLubhzEFnTIZd%2B50xx%2B7LSYK05qAvqFyFWhfFQDlnrzuBZ6brJFe%2BGnY%2BEgPbk6ZGQ3BebYhtF8GaV0nxvwuo77x%2FPy9auJ%2FGpsMiu%2FX1%2BmvoiBOv%2F2X%2FqkSsisRcOj%2FKKNFtY2PwByVS5uCbMiogziUwthDyC3%2B6WVwW6LLv3xLfHTjuCvjHIInNzktHCgKQ5ORAzI4JMPJ%2BGslWYHb4phowim57iaztXOoJwTdwJx4nLCgdNbOhdjsnvzqvHu7UrTkXWStAmzOVyyghqpZXjFaH3pO3JLF%2Bl%2B%2F%2BsKAIuvtd7u%2BNxe5AW0wdeRlN8NwdCjNPElpzVmbUq4JUagEiuTDkHzsxHpFKVK7q4%2B63SM1N95R1NbdWhscdCb%2BZAJzVcoyi3B43njTOQ5yOf%2B1CceWxG1bQVs5ZufpsMljq4Ui0%2F1lvh%2BwjChP4kqKOJ2qxq4RgqsahDYVvTH9w7jXbyLeiNdd8XM2w9U%2Ft7y0Ff%2F9yi0GE44Za4rF2LN9d11TPAmRGunUHBcnWEvgJBQl9nJEiU0Zsnvgc%2FubhPgXRR4Xq37Z0j4r7g1SgEEzwxA57demyPxgcYxn%2FeR44%2FKJ4EBs%2BlVDR3veyJm%2BkXQ99b21%2F%2Bjh5Xos1AnX5iItreGCc%3D
Question
Trouvez le certificat, inclus dans le navigateur, qui permet de valider la confiance dans le certificat du site Librecours.
Solution
On constate que le certificat Let's Encrypt, qui a signé le certificat de Librecours, est présent dans notre navigateur.