PACKAGE(5)

NAME
package - format for OpenBSD binary packages

DESCRIPTION
Binary packages for OpenBSD can be created using pkg_create(1) and are usually manipulated using pkg_add(1), pkg_mklocatedb(1), or pkg_info(1).

The basic underlying format is an archive following the ustar specification that can be handled with tar(1) and compressed using gzip(1).

Package names always end in “.tgz”; the file name itself should conform to packages-specs(7).

Note that the base distribution tarballs of OpenBSD (e.g. baseXX.tgz, compXX.tgz, ...) are not binary packages fit for pkg_add(1).

All types of archive contents can be present in a package, including files, directories, hardlinks, symlinks, fifos, block and character devices.

In order to allow just-in-time extraction, packages always begin with a table of contents, named +CONTENTS. This table of contents can be read using the API described in OpenBSD::PackingList(3p).

All the remaining information in the archive should be referenced in the packing-list, including all relevant information: symlinks destinations, special permissions, and file owners ( pkg_create(1) and pkg_add(1) actually enforce this). See pkg_create(1) for annotation details.

This table of contents is always followed by a few special files, some of which are optional: the package description (+DESC), a display message (+DISPLAY), etc.

The basic ustar format has some limitations with respect to file names. Packages now use the "extended record specification" (header type x) for long links and long file names. Other extended ustar headers are currently recognized, but not supported.

Starting with OpenBSD 5.5, the compressed archive may be composed of several gzip(1) archives concatenated together. gzip(1) doesn't mind, and tar(1) is happy as long as the uncompressed stream is sane. This allows for faster signing and better rsync properties.

Starting with OpenBSD 5.6, tarballs are stored "out-of-order": each archive entry will match an entry in the packing-list (and all file-like entries will be matched), but the order will be adjusted so that most recently changed files come first, in order to allow faster updates.

PACKING LIST ANNOTATIONS
User annotations are described in pkg_create(1). The following annotations are automatically inserted during package creation and installations:

@arch arches
    List of architectures for which this package is intended. This corresponds to -A arches of pkg_create(1)

@comment pkgpath=path cdrom=yes/no ftp=yes/no
    Historical accident. This specific comment encodes the actual -D FULLPKGPATH, -D CDROM, and -D FTP arguments to pkg_create(1).

    @depend pkgpath: pkgspec: default Record a dependency declared using the option -P of pkg_create(1).

    @digital-signature style: date: b64sig Record a digital signature of the packing-list, corresponding to pkg_create(1)'s -s option.

@link name
    Added after a file entry by package to record that the entry is actually a hard link.

@localbase base
    Used internally to record the settings of -L option.

@name pkgname
    Set the name of the package. This name is potentially different than the name of the file it came in, and is used when keeping track of the package for later deinstallation. pkg_create(1) will derive this field from the package file name.

@option name
    Some options are automatically inserted by the package tools:

    firmware
        Set by fw_update(1) to trigger firmware-specific handling. In particular, firmware is hidden from normal updates.

    manual-installation
        Record that a package has been explicitly installed by the user, and not as a result of a dependency look-up. Refer to pkg_add(1)'s -a option for details.

@sha
    Added after a file entry by pkg_create(1) to record the files's cryptographic checksum, as a sha256 digest encoded in base64.

@signer
    Internal annotation necessary to identify packages signed with signify(1) keys, as those keys don't carry any identity.

@size
    Added after a file entry by pkg_create(1) to record a file size.

@symlink name
    Added after a file entry by pkg_create(1) to record that the entry is actually a symbolic link.

@url
    Original location of the package, automatically recorded in installed packages by pkg_add(1).

@ts timestamp
    Added after a file entry to record the actual file timestamp. The package tools read and process that annotation correctly. Starting with OpenBSD 5.7, pkg_create(1) will migrate timestamps from the tarball meta-info to the packing-list to better create unchanging archive chunks.

@wantlib libspec
    Record a library requirement declared using the option -W of pkg_create(1).

PACKAGE SIGNATURES
All information within a package is checksummed, using SHA256 since OpenBSD 4.4. During creation and installation, meta-information, such as file owners and permissions, are also checked: any important stuff that isn't recorded in the packing-list is an error.

Packing-lists can be signed. If a signature is found, then it will be checked during installation, and failure to verify will prevent the package from installing correctly. Currently, signify(1) and X.509-style signatures are supported. X.509 signatures rely on a certificate authority file being present as /etc/ssl/pkgca.pem and all signatures will be checked against it. Once the packing-list signature is checked, all individual packing elements will be checksummed, resulting in a ‘just-in-time’ signature checking.

Fat packages were removed in OpenBSD 5.1, since no practical application was found.

SEE ALSO
pkg_add(1), pkg_create(1), pkg_info(1), pkg_sign(1), packages(7), packages-specs(7)

STANDARDS
Packages are valid gzip'ed ustar archives that can be extracted using tar(1). In particular, hardlink names should be valid, and all items will extract to different names. However, it may be a bit difficult to make sense of the package contents without peeking at the packing-list.