* add IPv6 reject packet generation (ICMPv6 Destination Unreachable and TCP RST)
* use ICMPv6 code 1 (administratively prohibited) and cap body at 1000 bytes
* cleanup, use ICMP error code 13 for ipv4
* better docs
* cleanup
* add sshd.sandbox_dir config option
Sanitize SSH profile paths (ssh.go:514,683,719) — restrict os.Create(a[0]) to a safe directory.
Add a config option in the config file to specify the sandbox directory. For backwards compatibility, if the config is not specified, keep the current behavior.
* update default and example
* use os.TempDir() for sshd.sandbox_dir default
* split sandbox path validation into separate conditionals
Separate the combined && check in sshSanitizeFilePath into two distinct
conditionals with specific error messages: one for paths resolving to the
sandbox directory itself, and one for paths outside the sandbox.
Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com>
* fix: trim leading zeros from p256 signature swap result
bigmod.Nat.Bytes() returns fixed-size 32-byte slices, but ASN.1 INTEGER
parsing strips leading zeros. This caused a flaky test failure (~1/256
chance) when the S value's high byte was zero.
Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com>
---------
Co-authored-by: Claude <svc-devxp-claude@slack-corp.com>
- Accept certs signed by trusted CAs
- Username must match the cert principal if set
- Any username can be used if cert principal is empty
- Don't allow removed pubkeys/CAs to be used after reload
* add calculated_remotes
This setting allows us to "guess" what the remote might be for a host
while we wait for the lighthouse response. For networks that hard
designed with in mind, it can help speed up handshake performance, as well as
improve resiliency in the case that all lighthouses are down.
Example:
lighthouse:
# ...
calculated_remotes:
# For any Nebula IPs in 10.0.10.0/24, this will apply the mask and add
# the calculated IP as an initial remote (while we wait for the response
# from the lighthouse). Both CIDRs must have the same mask size.
# For example, Nebula IP 10.0.10.123 will have a calculated remote of
# 192.168.1.123
10.0.10.0/24:
- mask: 192.168.1.0/24
port: 4242
* figure out what is up with this test
* add test
* better logic for sending handshakes
Keep track of the last light of hosts we sent handshakes to. Only log
handshake sent messages if the list has changed.
Remove the test Test_NewHandshakeManagerTrigger because it is faulty and
makes no sense. It relys on the fact that no handshake packets actually
get sent, but with these changes we would send packets now (which it
should!)
* use atomic.Pointer
* cleanup to make it clearer
* fix typo in example
* firewall: add option to send REJECT replies
This change allows you to configure the firewall to send REJECT packets
when a packet is denied.
firewall:
# Action to take when a packet is not allowed by the firewall rules.
# Can be one of:
# `drop` (default): silently drop the packet.
# `reject`: send a reject reply.
# - For TCP, this will be a RST "Connection Reset" packet.
# - For other protocols, this will be an ICMP port unreachable packet.
outbound_action: drop
inbound_action: drop
These packets are only sent to established tunnels, and only on the
overlay network (currently IPv4 only).
$ ping -c1 192.168.100.3
PING 192.168.100.3 (192.168.100.3) 56(84) bytes of data.
From 192.168.100.3 icmp_seq=2 Destination Port Unreachable
--- 192.168.100.3 ping statistics ---
2 packets transmitted, 0 received, +1 errors, 100% packet loss, time 31ms
$ nc -nzv 192.168.100.3 22
(UNKNOWN) [192.168.100.3] 22 (?) : Connection refused
This change also modifies the smoke test to capture tcpdump pcaps from
both the inside and outside to inspect what is going on over the wire.
It also now does TCP and UDP packet tests using the Nmap version of
ncat.
* calculate seq and ack the same was as the kernel
The logic a bit confusing, so we copy it straight from how the kernel
does iptables `--reject-with tcp-reset`:
- https://github.com/torvalds/linux/blob/v5.19/net/ipv4/netfilter/nf_reject_ipv4.c#L193-L221
* cleanup
* Add nss-lookup to the systemd wants to ensure DNS is running before starting nebula
* Add Ansible & example service scripts
* Fix#797
* Align Ansible scripts and examples
Co-authored-by: John Maguire <contact@johnmaguire.me>
By default, Nebula replies to packets it has no tunnel for with a `recv_error` packet. This packet helps speed up re-connection
in the case that Nebula on either side did not shut down cleanly. This response can be abused as a way to discover if Nebula is running
on a host though. This option lets you configure if you want to send `recv_error` packets always, never, or only to private network remotes.
valid values: always, never, private
This setting is reloadable with SIGHUP.
Wade Simmons