NAME

tacd — TLS-ALPN Challenge Daemon

SYNOPSIS

DESCRIPTION

tacd is a server that will listen to incoming Transport Layer Security (TLS) connections and, if the acme-tls/1 protocol has been declared during the Application-Layer Protocol Negotiation (ALPN), present a self-signed certificate in order to attempt to solve the TLS-ALPN-01 challenge. It then drops the connection.

In order to generate the self-signed certificate, it is required to specify both the domain name to validate and the acmeIdentifier extension. If one of those values is not specified using the available options, it is read from the standard input. When reading from the standard input, a new line character is expected at the end. In the case both values needs to be read from the standard input, the domain name is read first, then the acmeIdentifier extension.

The options are as follows:

-e, --acme-ext STRING

The acmeIdentifier extension to set in the self-signed certificate.

--acme-ext-file FILE

File from which is read the acmeIdentifier extension to set in the self-signed certificate.

--crt-digest STRING

Set the certificate's digest algorithm. Possible values are:

• sha256
• sha384
• sha512

--crt-signature-alg STRING

Set the certificate's signature algorithm. Possible values depends on the cryptographic library support and can be listed using the --help flag.

-d, --domain STRING

The domain that is being validated.

--domain-file STRING

File from which is read the domain that is being validated.

-f, --foreground

Runs in the foreground.

-h, --help

Prints help information.

-i, --listen host:port | unix:path

Specifies the host and port combination or the unix socket to listen on.

--log-stderr

Prints log messages to the standard error output.

--log-syslog

Sends log messages via syslog.

--log-level LEVEL

Specify the log level. Possible values: error, warn, info, debug and trace.

--no-pid-file

Do not create any PID file

--pid-file FILE

Specifies the location of the PID file.

-V, --version

Prints version information.

SEE ALSO

acmed.toml(5)

STANDARDS

R.B. Shoemaker, Automated Certificate Management Environment (ACME) TLS Application-Layer Protocol Negotiation (ALPN) Challenge Extension, RFC 8737, February 2020.

AUTHORS

Rodolphe Bréard ⟨rodolphe@breard.tf⟩