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2026-10-16
Most HTTPS problems boil down to a few reasons: incomplete certificate chain, expired certificate, incorrect name in the certificate, mismatch of versions or ciphers, or interference by intermediate equipment. The …
Read more2026-10-14
curl is a command-line HTTP client available on Linux, macOS and Windows 10 and newer. For debugging it is more convenient than a browser: it shows the full request and response, allows you to set any header and method, …
Read more2026-10-12
JA3 and JA4 — methods to obtain a short TLS client fingerprint from its initial ClientHello message. Different programs — Chrome, Firefox, curl, the Python requests library, the Go client, a malicious program — form …
Read more2026-10-09
The user types example.ru in the address bar without a scheme, follows an old http://… link, or opens a decade-old bookmark. In all these cases the first request may go over plain HTTP, and the site owner’s job is …
Read more2026-10-07
ECH (Encrypted Client Hello) — a TLS 1.3 extension that encrypts the first handshake message, ClientHello. The main thing it hides is the site name in the SNI field. Without ECH any node between you and the server can …
Read more2026-10-05
Under the phrase “TLS type” people usually mean different things: protocol version (1.2 or 1.3), cipher suite, certificate type (DV, OV, EV) or a scheme where the client also presents a certificate (mTLS). In this part — …
Read more2026-10-02
HTTPS — this is HTTP transmitted inside a TLS (Transport Layer Security) connection. TLS solves three problems: it encrypts data so they cannot be read in transit; it verifies integrity so they cannot be altered; and it …
Read more2026-09-30
HTTP has three versions in active use: HTTP/1.1, HTTP/2, and HTTP/3. Methods, headers, and status codes are the same across them, so an application usually doesn’t care which version a request arrived with. The …
Read more2026-09-28
Headers are the metadata of an HTTP message: lines like Name: value between the start-line and the body. From them the server understands which site is requested, in what format and language to return the response, who …
Read more2026-09-25
HTTP (HyperText Transfer Protocol) — an application-layer protocol by which a browser, mobile app, or script requests a resource from a server and receives a response. A resource can be an HTML page, an image, JSON from …
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