doc/man1/openssl-ech.pod.in

=pod
{- OpenSSL::safe::output_do_not_edit_headers(); -}

=head1 NAME

openssl-ech - ECH key generation

=head1 SYNOPSIS

B<openssl> B<ech>
[B<-help>]
[B<-verbose>]
[B<-in> I<files>]
[B<-out> I<file>]
[B<-public_name> I<name>]
[B<-max_name_len> I<len>]
[B<-suite> I<suite_str>]
[B<-ech_version> I<version>]
[B<-select> I<number>]
[B<-text>]

=head1 DESCRIPTION

The L<openssl-ech(1)> command generates Encrypted Client Hello (ECH) key pairs
in the ECHConfig PEM file format as specified in
L<https://datatracker.ietf.org/doc/rfc9934>.

That format consists of an optional private key in PKCS#8 format and a base64
encoded ECHConfigList containing an entry with a matching public value (and
possibly other entries as well).

=head1 OPTIONS

The following options are supported:

=over 4

=item B<-help>

Print out a usage message.

=item B<-verbose>

Print more verbosely.

=item B<-in>

Provide an input ECH PEM file for printing or merging. Up to five
input files can be provided via use of multiple B<in> arguments.

=item B<-out> I<file>

Name of output ECHConfig PEM file.  If a new key pair was generated the output
file will contain the private key and encoded ECHConfigList.  If one or more
input files was provided the output file will contain a set of ECHConfigList
values with public keys from the inputs, and no private key(s).

=item B<-text>

Provide human-readable text output.

=item B<-public_name> I<name>

The DNS name to use in the "public_name" field of the ECHConfig.

=item B<-max_name_len> I<num>

Maximum name length field value to use in the ECHConfig.

=item B<-suite> I<str>

HPKE suite to use in the ECHConfig.

=item B<-ech_version> I<version>

The ECH version to use in the ECHConfig. Only 0xfe0d is supported in this version.

=item B<-select> I<number>

Select the N-th ECHConfig/public key from the set of input ECH PEM files and output
that.

=back

=head1 NOTES

Ciphersuites are specified using a comma-separated list of IANA-registered
codes/numbers e.g. "-c 0x20,1,3" or a comma-separated list of strings from:
- KEMs: p256, p384, p521, x25519, x448
- KDFs: hkdf-sha256, hkdf-sha384, hkdf-sha512
- AEADs: aes128gcm, aes256gcm, chachapoly1305

For example the default is: x25519, hkdf-sha256, aes128gcm
See L<OSSL_HPKE_CTX_new(3)> for details.

=head1 SEE ALSO

L<openssl(1)>,
L<openssl-s_client(1)>,
L<openssl-s_server(1)>,
L<SSL_set1_echstore(3)>

=head1 HISTORY

This functionality described here was added in OpenSSL 4.0.

=head1 COPYRIGHT

Copyright 2024 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.

=cut