1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Long: ech 5Arg: <config> 6Help: Configure ECH 7Added: 8.8.0 8Category: tls 9Protocols: HTTPS 10Multi: single 11See-also: 12 - doh-url 13Example: 14 - --ech true $URL 15--- 16 17# `--ech` 18 19Specifies how to do ECH (Encrypted Client Hello). 20 21The values allowed for \<config\> can be: 22 23## "false" (default) 24 25Do not attempt ECH 26 27## "grease" 28 29Send a GREASE ECH extension 30 31## "true" 32 33Attempt ECH if possible, but do not fail if ECH is not attempted. 34(The connection fails if ECH is attempted but fails.) 35 36## "hard" 37 38Attempt ECH and fail if that is not possible. 39ECH only works with TLS 1.3 and also requires using 40DoH or providing an ECHConfigList on the command line. 41 42## "ecl:<b64val>" 43 44A base64 encoded ECHConfigList that is used for ECH. 45 46## "pn:<name>" 47 48A name to use to over-ride the `public_name` field of an ECHConfigList 49(only available with OpenSSL TLS support) 50 51## Errors 52 53Most errors cause error 54*CURLE_ECH_REQUIRED* (101). 55
