This adds most basic operation for doing DNSSEC validation on the
client side. However, it does not actually add the verification logic to
the resolver. Specifically, this patch only includes:
- Verifying DNSKEY RRs against a DS RRs
- Verifying RRSets against a combination of RRSIG and DNSKEY RRs
- Matching up RRSIG RRs and DNSKEY RRs
- Matching up RR keys and RRSIG RRs
- Calculating the DNSSEC key tag from a DNSKEY RR
All currently used DNSSEC combinations of SHA and RSA are implemented. Support
for MD5 hashing and DSA or EC cyphers are not. MD5 and DSA are probably
obsolete, and shouldn't be added. EC should probably be added
eventually, if it actually is deployed on the Internet.
Now that we have dns_resource_record_to_wire_format() we can generate
the RR serialization we return to bus clients in ResolveRecord() with
it. We pass the RR data along in the original form, not the DNSSEC
canonical form, since that would mean we'd lose RR name casing, which is
however important to keep for DNS-SD services and similar.
This adds dns_resource_record_to_wire_format() that generates the raw
wire-format of a single DnsResourceRecord object, and caches it in the
object, optionally in DNSSEC canonical form. This call is used later to
generate the RR serialization of RRs to verify.
This adds four new fields to DnsResourceRecord objects:
- wire_format points to the buffer with the wire-format version of the
RR
- wire_format_size stores the size of that buffer
- wire_format_rdata_offset specifies the index into the buffer where the
RDATA of the RR begins (i.e. the size of the key part of the RR).
- wire_format_canonical is a boolean that stores whether the cached wire
format is in DNSSEC canonical form or not.
Note that this patch adds a mode where a DnsPacket is allocated on the
stack (instead of on the heap), so that it is cheaper to reuse the
DnsPacket object for generating this wire format. After all we reuse the
DnsPacket object for this, since it comes with all the dynamic memory
management, and serialization calls we need anyway.
When verifying signatures we need to be able to verify the original
data we got for an RR set, and that means we cannot simply drop flags
bits or consider RRs invalid too eagerly. Hence, instead of parsing the
DNSKEY flags store them as-is. Similar, accept the protocol field as it
is, and don't consider it a parsing error if it is not 3.
Of course, this means that the DNSKEY handling code later on needs to
check explicit for protocol != 3.
We need to check the same thing in multiple tests. Use a shared
macro to make it easier to update the list of errnos.
Change the errno code for "unitialized cgroup fs" for ENOMEDIUM.
Exec format error looks like something more serious.
This fixes test-execute invocation in mock.
Let's merge access_init() and mac_selinux_access_init(), and only call
mac_selinux_use() once, inside the merged function, instead of multiple
times, including in the caller.
See comments on:
https://github.com/systemd/systemd/pull/2053
Make sure dns_name_normalize(), dns_name_concat(), dns_name_is_valid()
do not accept/generate invalidly long hostnames, i.e. longer than 253
characters.
Labels of zero length are not OK, refuse them early on. The concept of a
"zero-length label" doesn't exist, a zero-length full domain name
however does (representing the root domain). See RFC 2181, Section 11.
When we have non-owner user or group entries, we need the mask
for the acl to be valid. But acl_calc_mask() calculates the mask
to include all permissions, even those that were masked before.
Apparently this happens when we inherit *:r-x permissions from
a parent directory — the kernel sets *:r-x, mask:r--, effectively
masking the executable bit. acl_calc_mask() would set the mask:r-x,
effectively enabling the bit. To avoid this, be more conservative when
to add the mask entry: first iterate over all entries, and do nothing
if a mask.
This returns the code closer to J.A.Steffens' original version
in v204-90-g23ad4dd884.
Should fix https://github.com/systemd/systemd/issues/1977.
For now, only add_acls_for_user is tested. When run under root, it
actually sets the acls. When run under non-root, it sets the acls for
the user, which does nothing, but at least calls the functions.
Most of the function is moved to acl-util.c to make it possible to
add tests in subsequent commit.
Setting of the mode in server_fix_perms is removed:
- we either just created the file ourselves, and the permission be better right,
- or the file was already there, and we should not modify the permissions.
server_fix_perms is renamed to server_fix_acls to better reflect new
meaning, and made static because it is only used in one file.
This renames __useless_struct_to_allow_trailing_semicolon__ everywhere
to _sd_useless_struct_to_allow_trailing_semicolon_, to follow our usual
rule of prefixing stuff from public headers that should be considered
internal with "_sd_".
While we are at it, also to be safe: when the struct is used in the C++
protector macros make sure to use two different names depending on
whether it appears in the C++ or C side of things. After all, there
might be compilers that don't consider C++ and C structs the same.
See https://github.com/systemd/systemd/pull/2052#discussion_r46067059
Let's distuingish the cases where our code takes an active role in
selinux management, or just passively reports whatever selinux
properties are set.
mac_selinux_have() now checks whether selinux is around for the passive
stuff, and mac_selinux_use() for the active stuff. The latter checks the
former, plus also checks UID == 0, under the assumption that only when
we run priviliged selinux management really makes sense.
Fixes: #1941
The header file defines some helpers for GLIBC NSS and doesn't include
anything else but glibc headers, hence there's little reason to keep it
in shared/.
See: #2008
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.
With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.
The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).
This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.
Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:
#define _cleanup_(function) __attribute__((cleanup(function)))
Or similar, to make the gcc feature easier to use.
Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.
See #2008.
If pid < 0 after fork(), 0 is always returned because r =
exec_context_load_environment() has exited successfully.
This will make the caller of exec_spawn() not able to handle
the fork() error case and make systemd abort assert() possibly.
