{"id":4559,"date":"2025-03-17T15:08:23","date_gmt":"2025-03-17T14:08:23","guid":{"rendered":"https:\/\/andreas-klingler.de\/infosec\/?p=4559"},"modified":"2025-03-17T15:09:55","modified_gmt":"2025-03-17T14:09:55","slug":"tls-server-response-fingerprint","status":"publish","type":"post","link":"https:\/\/infosec.andreas-klingler.de\/?p=4559","title":{"rendered":"<span class=\"caps\">TLS<\/span> Server Response Fingerprint"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\"><span class=\"caps\">JA4S<\/span> is a sys\u00adtem to hash the con\u00adfig\u00adu\u00adra\u00adtion of a <span class=\"caps\">TLS<\/span> con\u00adnec\u00adtion. More: <a href=\"https:\/\/github.com\/FoxIO-LLC\/ja4\/blob\/main\/technical_details\/README.md\">ja4\/technical_details\/<span class=\"caps\">README<\/span>.md at main \u00b7 FoxIO-LLC\/\u00adja4 \u00b7 GitHub<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pos\u00adsi\u00adble use&nbsp;cases:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Scan the net\u00adwork for this ja4s fin\u00adger\u00adprints and see if expect\u00aded <span class=\"caps\">TLS<\/span> fin\u00adger\u00adprints appear. Our sys\u00adtems nor\u00admal\u00adly should have only a known sub\u00adset of fingerprints.<\/li>\n\n\n\n<li>Block\u00ading of requests on fire\u00adwalls when hav\u00ading a dis\u00adtrib\u00aduted attack\u00ader, but its tool can be iden\u00adti\u00adfied by the request fingerprint.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p><span class=\"caps\">JA4S<\/span> is a sys\u00adtem to hash the con\u00adfig\u00adu\u00adra\u00adtion of a <span class=\"caps\">TLS<\/span> con\u00adnec\u00adtion. More: ja4\/technical_details\/<span class=\"caps\">README<\/span>.md at main \u00b7 FoxIO-LLC\/\u00ad\u00adja4 \u00b7 GitHub Pos\u00adsi\u00adble use&nbsp;cases:<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"wp_typography_post_enhancements_disabled":false,"footnotes":""},"categories":[476],"tags":[514,520,519,395],"class_list":["post-4559","post","type-post","status-publish","format-standard","hentry","category-defence-tool","tag-incident-response","tag-intruder-detection","tag-ja4s","tag-tls"],"_links":{"self":[{"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/posts\/4559","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4559"}],"version-history":[{"count":3,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/posts\/4559\/revisions"}],"predecessor-version":[{"id":4563,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/posts\/4559\/revisions\/4563"}],"wp:attachment":[{"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4559"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4559"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4559"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}