A new acme process is created that communicates with the acme servers.
This process does not hold any of your private keys (no account keys,
no domain keys etc).
Whenever the acme process requires a signed payload it will ask the keymgr
process to do the signing with the relevant keys.
This process is also sandboxed with pledge+unveil on OpenBSD and seccomp
syscall filtering on Linux.
The implementation only supports the tls-alpn-01 challenge. This means that
you do not need to open additional ports on your machine.
http-01 and dns-01 are currently not supported (no wildcard support).
A new configuration option "acme_provider" is available and can be set
to the acme server its directory. By default this will point to the
live letsencrypt environment:
https://acme-v02.api.letsencrypt.org/directory
The acme process can be controlled via the following config options:
- acme_root (where the acme process will chroot/chdir into).
- acme_runas (the user the acme process will run as).
If none are set, the values from 'root' and 'runas' are taken.
If you want to turn on acme for domains you do it as follows:
domain kore.io {
acme yes
}
You do not need to specify certkey/certfile anymore, if they are present
still
they will be overwritten by the acme system.
The keymgr will store all certificates and keys under its root
(keymgr_root), the account key is stored as "/account-key.pem" and all
obtained certificates go under "certificates/<domain>/fullchain.pem" while
keys go under "certificates/<domain>/key.pem".
Kore will automatically renew certificates if they will expire in 7 days
or less.
If set to "yes" then Kore will trace its child processes and properly
notify you of seccomp violations while still allowing the syscalls.
This can be very useful when running Kore on new platforms that have
not been properly tested with seccomp, allowing me to adjust the default
policies as we move further.
A new hook in the koreapp class is called right before seccomp
is enabled. This hook receives a Kore seccomp object which has
the following methods:
seccomp.allow("syscall")
seccomp.allow_arg("syscall", arg, value)
seccomp.allow_flag("syscall", arg, flag)
seccomp.allow_mask("syscall", arg, mask)
seccomp.deny("syscall")
seccomp.deny_arg("syscall", arg, value, errno=EACCES)
seccomp.deny_flag("syscall", arg, flag, errno=EACCES)
seccomp.deny_mask("syscall", arg, mask, errno=EACCES)
This allows you to finetune the seccomp filters for your application
from inside your koreapp.
Before kore needed to be built with NOTLS=1 to be able to do non TLS
connections. This has been like this for years.
It is time to allow non TLS listeners without having to rebuild Kore.
This commit changes your configuration format and will break existing
applications their config.
Configurations now get listener {} contexts:
listen default {
bind 127.0.0.1 8888
}
The above will create a listener on 127.0.0.1, port 8888 that will serve
TLS (still the default).
If you want to turn off TLS on that listener, specify "tls no" in that
context.
Domains now need to be attached to a listener:
Eg:
domain * {
attach default
}
For the Python API this kills kore.bind(), and kore.bind_unix(). They are
replaced with:
kore.listen("name", ip=None, port=None, path=None, tls=True).
More BPF helper macros, more helper for granular syscall checking.
Use these throughout kore where it makes sense.
The new helpers:
- KORE_SYSCALL_DENY_ARG(name, arg, value, errno):
Deny the system call with errno if the argument matches value.
- KORE_SYSCALL_DENY_MASK(name, arg, mask, errno):
Deny the system call with errno if the mask argument does not match
the exact mask given.
- KORE_SYSCALL_DENY_WITH_FLAG(name, arg, flag, errno):
Deny the system call with errno if the argument contains the
given flag.
The reverse also exists:
- KORE_SYSCALL_ALLOW_ARG()
- KORE_SYSCALL_ALLOW_MASK()
- KORE_SYSCALL_ALLOW_WITH_FLAG()
With this commit all Kore processes (minus the parent) are running
under seccomp.
The worker processes get the bare minimum allowed syscalls while each module
like curl, pgsql, etc will add their own filters to allow what they require.
New API functions:
int kore_seccomp_filter(const char *name, void *filter, size_t len);
Adds a filter into the seccomp system (must be called before
seccomp is enabled).
New helpful macro:
define KORE_SYSCALL_ALLOW(name)
Allow the syscall with a given name, should be used in
a sock_filter data structure.
New hooks:
void kore_seccomp_hook(void);
Called before seccomp is enabled, allows developers to add their
own BPF filters into seccomp.
Joris Vink
Joris Vink
Frederic Cambus