{"id":5644,"date":"2023-08-25T00:00:00","date_gmt":"2023-08-25T00:00:00","guid":{"rendered":"https:\/\/tech-lib.eu\/tech\/jak-napsat-captcha-kod\/"},"modified":"2023-08-25T00:00:00","modified_gmt":"2023-08-25T00:00:00","slug":"jak-napsat-captcha-kod","status":"publish","type":"post","link":"https:\/\/tech-lib.eu\/tech\/jak-napsat-captcha-kod\/","title":{"rendered":"Jak napsat CAPTCHA k\u00f3d"},"content":{"rendered":"
\n
Co je Zakliknut\u00ed CAPTCHA?<\/div>\n
Co je Captcha? Jak v\u011bt\u0161ina z v\u00e1s z\u0159ejm\u011b v\u00ed, Captcha je lidov\u011b zn\u00e1ma jako antispamov\u00e1 ochrana formul\u00e1\u0159\u016f, kde mus\u00ed u\u017eivatel pro dokon\u010den\u00ed akce (p\u0159i psan\u00ed diskuzn\u00edho p\u0159\u00edsp\u011bvku nebo odesl\u00e1n\u00ed kontaktn\u00edho formul\u00e1\u0159e) opsat zobrazen\u00fd text nebo zakliknout, \u017ee nen\u00ed robot. Cached<\/div>\n
\n\t\t\t\t\t Dal\u0161\u00ed informace najdete na<\/span> blog.eshop-rychle.cz<\/a>\n\t\t\t\t<\/div>\n<\/p><\/div>\n
Jako bezpe\u010dnostn\u00ed opat\u0159en\u00ed pou\u017e\u00edvaj\u00ed webov\u00e9 str\u00e1nky CAPTCHA (Completely Automated Public Turing Test to Tell Computers and Humans Apart), aby rozli\u0161ily mezi lidsk\u00fdmi u\u017eivateli a automatizovan\u00fdmi roboty. Pom\u00e1h\u00e1 p\u0159edch\u00e1zet spamu, \u00fatok\u016fm hrubou silou a dal\u0161\u00edm \u0161kodliv\u00fdm praktik\u00e1m. Tento \u010dl\u00e1nek se bude zab\u00fdvat k\u00f3dov\u00e1n\u00edm CAPTCHA a nab\u00eddne p\u0159\u00edklady v n\u011bkolika po\u010d\u00edta\u010dov\u00fdch jazyc\u00edch. <\/p>\n
Jak vypad\u00e1 k\u00f3d CAPTCHA? <\/div>\n

Typick\u00fd k\u00f3d CAPTCHA se skl\u00e1d\u00e1 ze zkreslen\u00e9ho obr\u00e1zku s abecedn\u00edmi znaky, kter\u00e9 mus\u00ed u\u017eivatel\u00e9 p\u0159esn\u011b zadat, aby se ov\u011b\u0159ila jejich lidsk\u00e1 identita. Vedle k\u00f3du je \u010dasto vid\u011bt textov\u00e9 pole, do kter\u00e9ho spot\u0159ebitel\u00e9 zad\u00e1vaj\u00ed svou odpov\u011b\u010f. Aby bylo pro roboty obt\u00ed\u017en\u00e9 k\u00f3d p\u0159e\u010d\u00edst a pochopit, jsou znaky na obr\u00e1zku n\u00e1hodn\u011b rozm\u00edst\u011bny a pok\u0159iveny. <\/p>\n

Jak vytvo\u0159it HTML CAPTCHA? <\/div>\n

Pro vytvo\u0159en\u00ed CAPTCHA v jazyce HTML m\u016f\u017eete kombinovat jazyky HTML, CSS a JavaScript. Zde je podrobn\u00fd n\u00e1vod: <\/p>\n

<\/div>\n

1. Navrhn\u011bte formul\u00e1\u0159 HTML obsahuj\u00edc\u00ed pole pro vstup u\u017eivatele, zna\u010dku obr\u00e1zku pro obr\u00e1zek CAPTCHA a tla\u010d\u00edtko pro odesl\u00e1n\u00ed formul\u00e1\u0159e. 2. Vytvo\u0159te n\u00e1hodn\u00fd \u0159et\u011bzec znak\u016f, kter\u00fd pou\u017eijete jako k\u00f3d CAPTCHA. 3. Pro ozdoben\u00ed obr\u00e1zku CAPTCHA pou\u017eijte CSS a v p\u0159\u00edpad\u011b pot\u0159eby p\u0159idejte efekty zkreslen\u00ed. <\/p>\n

<\/div>\n

4. P\u0159i odes\u00edl\u00e1n\u00ed formul\u00e1\u0159e pou\u017eijte JavaScript k ov\u011b\u0159en\u00ed odpov\u011bdi u\u017eivatele a aktualizujte zdroj obr\u00e1zku s vytvo\u0159en\u00fdm k\u00f3dem CAPTCHA. <\/p>\n

<\/div>\n

Pro implementaci CAPTCHA v HTML je nutn\u00e1 z\u00e1kladn\u00ed znalost t\u011bchto technologi\u00ed a je nezbytn\u00e9 zajistit, aby byl k\u00f3d CAPTCHA generov\u00e1n bezpe\u010dn\u011b a znemo\u017enil tak robot\u016fm jeho snadn\u00e9 rozlu\u0161t\u011bn\u00ed. <\/p>\n

<\/div>\n

Jak vytvo\u0159it CAPTCHA v jazyce C? Pro vytvo\u0159en\u00ed CAPTCHA v jazyce C je t\u0159eba vygenerovat n\u00e1hodnou sekvenci znak\u016f, vykreslit ji jako obr\u00e1zek a ov\u011b\u0159it odpov\u011b\u010f u\u017eivatele. Zde je obecn\u00fd rozpis postup\u016f: <\/p>\n

<\/div>\n

Chcete-li vytvo\u0159it k\u00f3d CAPTCHA, vytvo\u0159te nejprve n\u00e1hodn\u00fd \u0159et\u011bzec znak\u016f. <\/p>\n

<\/div>\n

2. Chcete-li vytvo\u0159it obr\u00e1zek, kter\u00fd zobraz\u00ed k\u00f3d CAPTCHA, pou\u017eijte grafick\u00fd bal\u00edk, nap\u0159\u00edklad OpenCV nebo Cairo. 3. Do obr\u00e1zku p\u0159idejte n\u00e1hodn\u00e1 zkreslen\u00ed, nap\u0159\u00edklad oto\u010den\u00ed, \u0161k\u00e1lov\u00e1n\u00ed a \u0161um. 4. Obr\u00e1zek CAPTCHA m\u016f\u017eete bu\u010f ihned vykreslit na webov\u00e9 str\u00e1nce, nebo jej ulo\u017eit do souboru. 5. Chcete-li potvrdit lidskou identitu u\u017eivatele, porovnejte jeho dodanou odpov\u011b\u010f s vytvo\u0159en\u00fdm k\u00f3dem CAPTCHA. <\/p>\n

<\/div>\n

Porozum\u011bn\u00ed knihovn\u00e1m a metod\u00e1m zpracov\u00e1n\u00ed obr\u00e1zk\u016f je nezbytn\u00e9 pro vytvo\u0159en\u00ed CAPTCHA v jazyce C. Je t\u0159eba pou\u017e\u00edt metody siln\u00e9ho zkreslen\u00ed, aby bylo pro roboty obt\u00ed\u017en\u00e9 k\u00f3d rozlu\u0161tit. <\/p>\n

Co je to k\u00f3d CAPTCHA, kter\u00fd je neplatn\u00fd? <\/div>\n

Pokud odpov\u011b\u010f neodpov\u00edd\u00e1 zam\u00fd\u0161len\u00e9mu zad\u00e1n\u00ed, je k\u00f3d CAPTCHA pova\u017eov\u00e1n za nespr\u00e1vn\u00fd. U\u017eivatel m\u016f\u017ee b\u00fdt bot nebo se dopustil chyby, pokud jeho odeslan\u00e1 odpov\u011b\u010f neodpov\u00edd\u00e1 zobrazen\u00e9mu k\u00f3du CAPTCHA. Chcete-li zastavit automatick\u00e9 odes\u00edl\u00e1n\u00ed formul\u00e1\u0159\u016f nebo podez\u0159el\u00e9 aktivity, pou\u017e\u00edvejte neplatn\u00e9 k\u00f3dy CAPTCHA. <\/p>\n

<\/div>\n

Shrneme-li to, vytv\u00e1\u0159en\u00ed n\u00e1hodn\u00fdch znak\u016f, jejich zkreslov\u00e1n\u00ed do obr\u00e1zk\u016f a vyhodnocov\u00e1n\u00ed u\u017eivatelsk\u00fdch vstup\u016f jsou sou\u010d\u00e1st\u00ed tvorby k\u00f3du CAPTCHA. P\u0159i implementaci CAPTCHA je z\u00e1sadn\u00ed zajistit, aby byl k\u00f3d u\u017eivatelsky p\u0159\u00edv\u011btiv\u00fd a z\u00e1rove\u0148 dostate\u010dn\u011b odoln\u00fd pro roboty, a\u0165 u\u017e pou\u017e\u00edv\u00e1te jazyk HTML nebo C. Va\u0161e online aplikace mohou b\u00fdt d\u00edky implementaci CAPTCHA bezpe\u010dn\u011bj\u0161\u00ed a chr\u00e1n\u011bn\u00e9 p\u0159ed \u0161kodlivou \u010dinnost\u00ed.<\/p><\/div>\n

\n
FAQ<\/div>\n
\n
Kolik \u010d\u00edslic m\u00e1 k\u00f3d CAPTCHA?<\/div>\n

K\u00f3d CAPTCHA m\u016f\u017ee m\u00edt libovolnou d\u00e9lku, ale nej\u010dast\u011bji se jedn\u00e1 o 4 a\u017e 6 alfanumerick\u00fdch znak\u016f. <\/p>\n<\/div>\n

\n
Co je nespr\u00e1vn\u00fd k\u00f3d CAPTCHA?<\/div>\n

Kdy\u017e se u\u017eivatel pokus\u00ed vy\u0159e\u0161it k\u00f3d CAPTCHA, ale nepoda\u0159\u00ed se mu to nebo ud\u011bl\u00e1 chybu p\u0159i zad\u00e1v\u00e1n\u00ed po\u017eadovan\u00fdch znak\u016f nebo symbol\u016f, ozna\u010duje se to jako nespr\u00e1vn\u00fd k\u00f3d CAPTCHA. K tomu m\u016f\u017ee doj\u00edt z n\u011bkolika d\u016fvod\u016f, v\u010detn\u011b nepochopen\u00ed k\u00f3dovan\u00fdch nebo maskovan\u00fdch znak\u016f, zad\u00e1n\u00ed chybn\u00fdch znak\u016f nebo odesl\u00e1n\u00ed odpov\u011bdi v nespr\u00e1vn\u00e9m form\u00e1tu. <\/p>\n<\/div>\n

\n
Co je reCAPTCHA v HTML?<\/div>\n

Typ k\u00f3du CAPTCHA (Completely Automated Public Turing Test to Tell Computers and Humans Apart) nazvan\u00fd reCAPTCHA se v HTML pou\u017e\u00edv\u00e1 k ur\u010den\u00ed, zda je u\u017eivatel \u010dlov\u011bk, nebo po\u010d\u00edta\u010dov\u00fd program. Jedn\u00e1 se o bezplatn\u00fd n\u00e1stroj nab\u00edzen\u00fd spole\u010dnost\u00ed Google, kter\u00fd pom\u00e1h\u00e1 zastavit automatizovan\u00e9 zneu\u017e\u00edv\u00e1n\u00ed webov\u00fdch str\u00e1nek, nap\u0159\u00edklad spam a trestnou \u010dinnost. Aby se ov\u011b\u0159ilo, \u017ee u\u017eivatel je skute\u010dn\u00e1 osoba, a nikoli po\u010d\u00edta\u010dov\u00fd program, je k\u00f3d reCAPTCHA \u010dasto sou\u010d\u00e1st\u00ed webov\u00fdch formul\u00e1\u0159\u016f nebo p\u0159ihla\u0161ovac\u00edch str\u00e1nek. U\u017eivatel\u00e9 dost\u00e1vaj\u00ed \u00fakoly, jako je identifikace konkr\u00e9tn\u00edch v\u011bc\u00ed na obr\u00e1zc\u00edch nebo \u0159e\u0161en\u00ed h\u00e1danek, kter\u00e9 jsou jednoduch\u00e9 pro lidi, ale n\u00e1ro\u010dn\u00e9 pro roboty. Majitel\u00e9 webov\u00fdch str\u00e1nek mohou integrac\u00ed k\u00f3du reCAPTCHA do jazyka HTML pos\u00edlit sv\u00e9 bezpe\u010dnostn\u00ed protokoly a ochr\u00e1nit sv\u00e9 platformy p\u0159ed automatizovan\u00fdmi \u00fatoky.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Co je Zakliknut\u00ed CAPTCHA? Co je Captcha? Jak v\u011bt\u0161ina z v\u00e1s z\u0159ejm\u011b v\u00ed, Captcha je lidov\u011b zn\u00e1ma jako antispamov\u00e1 ochrana formul\u00e1\u0159\u016f, kde mus\u00ed u\u017eivatel pro dokon\u010den\u00ed akce (p\u0159i psan\u00ed diskuzn\u00edho p\u0159\u00edsp\u011bvku nebo odesl\u00e1n\u00ed kontaktn\u00edho formul\u00e1\u0159e) opsat zobrazen\u00fd text nebo zakliknout, \u017ee nen\u00ed robot. Cached Dal\u0161\u00ed informace najdete na blog.eshop-rychle.cz Jako bezpe\u010dnostn\u00ed opat\u0159en\u00ed pou\u017e\u00edvaj\u00ed webov\u00e9 str\u00e1nky … \u010c\u00edst d\u00e1l<\/a><\/p>\n","protected":false},"author":1756,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2283],"tags":[],"class_list":["post-5644","post","type-post","status-publish","format-standard","hentry","category-captcha-kod"],"_links":{"self":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/5644","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/users\/1756"}],"replies":[{"embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/comments?post=5644"}],"version-history":[{"count":0,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/5644\/revisions"}],"wp:attachment":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/media?parent=5644"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/categories?post=5644"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/tags?post=5644"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}