APT-TRANSPORT-HTTP(1) APT APT-TRANSPORT-HTTP(1)
NAME
apt-transport-https - APT transport for downloading via the HTTP Secure protocol (HTTPS)
DESCRIPTION
This APT transport allows the use of repositories accessed via the HTTP Secure protocol (HTTPS), also referred to as HTTP over TLS. It is
available by default since apt 1.5 and was available before that in the package apt-transport-https. Note that a transport is never called
directly by a user but used by APT tools based on user configuration.
HTTP is by itself an unencrypted transport protocol (compare apt-transport-http(1)), which, as indicated by the appended S, is wrapped in
an encrypted layer known as Transport Layer Security (TLS) to provide end-to-end encryption. A sufficiently capable attacker can still
observe the communication partners and deeper analyse of the encrypted communication might still reveal important details. An overview over
available alternative transport methods is given in sources.list(5).
OPTIONS
The HTTPS protocol is based on the HTTP protocol, so all options supported by apt-transport-http(1) are also available via Acquire::https
and will default to the same values specified for Acquire::http. This manpage will only document the options unique to https.
Server credentials
By default all certificates trusted by the system (see ca-certificates package) are used for the verification of the server certificate. An
alternative certificate authority (CA) can be configured with the Acquire::https::CAInfo option and its host-specific option
Acquire::https::CAInfo::host. The CAInfo option specifies a file made up of CA certificates (in PEM format) concatenated together to create
the chain which APT should use to verify the path from your self-signed root certificate. If the remote server provides the whole chain
during the exchange, the file need only contain the root certificate. Otherwise, the whole chain is required. If you need to support
multiple authorities, the only way is to concatenate everything.
A custom certificate revocation list (CRL) can be configured with the options Acquire::https::CRLFile and Acquire::https::CRLFile::host. As
with the previous option, a file in PEM format needs to be specified.
Disabling security
During server authentication, if certificate verification fails for some reason (expired, revoked, man in the middle, etc.), the connection
fails. This is obviously what you want in all cases and what the default value (true) of the option Acquire::https::Verify-Peer and its
host-specific variant provides. If you know exactly what you are doing, setting this option to "false" allows you to skip peer certificate
verification and make the exchange succeed. Again, this option is for debugging or testing purposes only as it removes all security
provided by the use of HTTPS.
Similarly the option Acquire::https::Verify-Host and its host-specific variant can be used to deactivate a security feature: The
certificate provided by the server includes the identity of the server which should match the DNS name used to access it. By default, as
requested by RFC 2818, the name of the mirror is checked against the identity found in the certificate. This default behavior is safe and
should not be changed, but if you know that the server you are using has a DNS name which does not match the identity in its certificate,
you can set the option to "false", which will prevent the comparison from being performed.
Client authentication
Besides supporting password-based authentication (see apt_auth.conf(5)) HTTPS also supports authentication based on client certificates via
Acquire::https::SSLCert and Acquire::https::SSLKey. These should be set respectively to the filename of the X.509 client certificate and
the associated (unencrypted) private key, both in PEM format. In practice the use of the host-specific variants of both options is highly
recommended.
EXAMPLES
Acquire::https {
Proxy::example.org "DIRECT";
Proxy "socks5h://apt:pass@localhost:9050";
Proxy-Auto-Detect "/usr/local/bin/apt-https-proxy-auto-detect";
No-Cache "true";
Max-Age "3600";
No-Store "true";
Timeout "10";
Dl-Limit "42";
Pipeline-Depth "0";
AllowRedirect "false";
User-Agent "My APT-HTTPS";
SendAccept "false";
CAInfo "/path/to/ca/certs.pem";
CRLFile "/path/to/all/crl.pem";
Verify-Peer "true";
Verify-Host::broken.example.org "false";
SSLCert::example.org "/path/to/client/cert.pem";
SSLKey::example.org "/path/to/client/key.pem"
};
SEE ALSO
apt-transport-http(1) apt.conf(5) apt_auth.conf(5) sources.list(5)
BUGS
APT bug page[1]. If you wish to report a bug in APT, please see /usr/share/doc/debian/bug-reporting.txt or the reportbug(1) command.
AUTHOR
APT team
NOTES
1. APT bug page
http://bugs.debian.org/src:apt
APT 1.6.3ubuntu0.1 20 August 2018 APT-TRANSPORT-HTTP(1)