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 analysis 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@127.0.0.1:9050";
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 2.1.7 11 May 2018 APT-TRANSPORT-HTTP(1)