The manpage mentions the trick to use PostUp to read the PrivateKey (or PresharedKey) from a command (or file). However, when you actually use that you notice that this is currently not fully supported. The issue is that
```Shell wg syncconf wgnet0 <(wg-quick strip wgnet0) ``` from the manpage now breaks the VPN because it *removes* the private key from the WireGuard interface. The reason is that `strip` removes PostUp of course. This patch tries to add full support to read WireGuard keys from files or command outputs by evaluating PostUp using a best effort approach (using regex). It will not work for everything but when you follow the manpage closely, it will work. I also propose to update the systemd template to make seamless use of this. This is not a must because the sysadmin can easily change the ExecReload using systemd drop-in files. Note that the patchset is incomplete (currently only for Linux). I don’t have all the other OSes laying around. When the patch looks ok, I can apply it to the other versions also. Example use of this patch: https://github.com/ypid/ansible-wireguard/tree/prepare-for-debops Signed-off-by: Robin Schneider <y...@riseup.net> --- src/man/wg-quick.8 | 9 +++++++++ src/systemd/wg-quick@.service | 2 +- src/wg-quick/linux.bash | 36 ++++++++++++++++++++++++++++++++--- 3 files changed, 43 insertions(+), 4 deletions(-) diff --git a/src/man/wg-quick.8 b/src/man/wg-quick.8 index b84eb64..f620704 100644 --- a/src/man/wg-quick.8 +++ b/src/man/wg-quick.8 @@ -13,6 +13,8 @@ wg-quick - set up a WireGuard interface simply .I save | .I strip +| +.I strip-and-eval ] [ .I CONFIG_FILE | @@ -34,6 +36,7 @@ with all .BR wg-quick (8)-specific options removed, suitable for use with .BR wg (8). +Use \fIstrip-and-eval\fP in case you use `PostUp' to read PrivateKey or PresharedKey from a file or command and need them in the output. \fICONFIG_FILE\fP is a configuration file, whose filename is the interface name followed by `.conf'. Otherwise, \fIINTERFACE\fP is an interface name, with configuration @@ -256,6 +259,12 @@ sessions: \fB # wg syncconf wgnet0 <(wg-quick strip wgnet0)\fP +\fIstrip-and-eval\fP additionally extracts PrivateKey and PresharedKey from `PostUp` statements and translates them into configuration that +.BR wg (8) +does understand: + +\fB # wg syncconf wgnet0 <(wg-quick strip-and-eval wgnet0)\fP + .SH SEE ALSO .BR wg (8), .BR ip (8), diff --git a/src/systemd/wg-quick@.service b/src/systemd/wg-quick@.service index dbdab44..1d59446 100644 --- a/src/systemd/wg-quick@.service +++ b/src/systemd/wg-quick@.service @@ -15,7 +15,7 @@ Type=oneshot RemainAfterExit=yes ExecStart=/usr/bin/wg-quick up %i ExecStop=/usr/bin/wg-quick down %i -ExecReload=/bin/bash -c 'exec /usr/bin/wg syncconf %i <(exec /usr/bin/wg-quick strip %i)' +ExecReload=/bin/bash -c 'exec /usr/bin/wg syncconf %i <(exec /usr/bin/wg-quick strip-and-eval %i)' Environment=WG_ENDPOINT_RESOLUTION_RETRIES=infinity [Install] diff --git a/src/wg-quick/linux.bash b/src/wg-quick/linux.bash index e4d4c4f..89f9ef9 100755 --- a/src/wg-quick/linux.bash +++ b/src/wg-quick/linux.bash @@ -38,8 +38,11 @@ die() { } parse_options() { + local parsing_mode part_of_command peer_pubkey local interface_section=0 line key value stripped v + declare -A peer_pubkey_to_psk CONFIG_FILE="$1" + parsing_mode="${2:-safe}" [[ $CONFIG_FILE =~ ^[a-zA-Z0-9_=+.-]{1,15}$ ]] && CONFIG_FILE="/etc/wireguard/$CONFIG_FILE.conf" [[ -e $CONFIG_FILE ]] || die "\`$CONFIG_FILE' does not exist" [[ $CONFIG_FILE =~ (^|/)([a-zA-Z0-9_=+.-]{1,15})\.conf$ ]] || die "The config file must be a valid interface name, followed by .conf" @@ -63,12 +66,35 @@ parse_options() { Table) TABLE="$value"; continue ;; PreUp) PRE_UP+=( "$value" ); continue ;; PreDown) PRE_DOWN+=( "$value" ); continue ;; - PostUp) POST_UP+=( "$value" ); continue ;; + PostUp) POST_UP+=( "$value" ); + if [[ $parsing_mode == "unsafe" ]]; then + part_of_command="" + if [[ $value =~ ^wg\ +set\ +%i\ +private-key\ +(.+)$ ]]; then + key='PrivateKey' + part_of_command="${BASH_REMATCH[1]}" + elif [[ $value =~ ^wg\ +set\ +%i\ +peer\ +(.+)\ +preshared-key\ +(.+)$ ]]; then + key='PresharedKey' + peer_pubkey="${BASH_REMATCH[1]}" + part_of_command="${BASH_REMATCH[2]}" + fi + if [[ -n "$part_of_command" ]]; then + part_of_command="${part_of_command//%i/$INTERFACE}" + value="$(eval "cat $part_of_command")" + case "$key" in + PresharedKey) peer_pubkey_to_psk["$peer_pubkey"]="$value" ;; + *) WG_CONFIG+="$key = $value"$'\n' ;; + esac + fi + fi + continue ;; PostDown) POST_DOWN+=( "$value" ); continue ;; SaveConfig) read_bool SAVE_CONFIG "$value"; continue ;; esac fi WG_CONFIG+="$line"$'\n' + if [[ $interface_section -eq 0 && $key == 'PublicKey' && -n "${peer_pubkey_to_psk[$value]}" ]]; then + WG_CONFIG+="PresharedKey = ${peer_pubkey_to_psk[$value]}"$'\n' + fi done < "$CONFIG_FILE" shopt -u nocasematch } @@ -224,7 +250,7 @@ add_default() { cmd ip $proto rule add not fwmark $table table $table cmd ip $proto rule add table main suppress_prefixlength 0 - local marker="-m comment --comment \"wg-quick(8) rule for $INTERFACE\"" restore=$'*raw\n' nftable="wg-quick-$INTERFACE" nftcmd + local marker="-m comment --comment \"wg-quick(8) rule for $INTERFACE\"" restore=$'*raw\n' nftable="wg-quick-$INTERFACE" nftcmd printf -v nftcmd '%sadd table %s %s\n' "$nftcmd" "$pf" "$nftable" printf -v nftcmd '%sadd chain %s %s preraw { type filter hook prerouting priority -300; }\n' "$nftcmd" "$pf" "$nftable" printf -v nftcmd '%sadd chain %s %s premangle { type filter hook prerouting priority -150; }\n' "$nftcmd" "$pf" "$nftable" @@ -298,7 +324,7 @@ execute_hooks() { cmd_usage() { cat >&2 <<-_EOF - Usage: $PROGRAM [ up | down | save | strip ] [ CONFIG_FILE | INTERFACE ] + Usage: $PROGRAM [ up | down | save | strip | strip-and-eval ] [ CONFIG_FILE | INTERFACE ] CONFIG_FILE is a configuration file, whose filename is the interface name followed by \`.conf'. Otherwise, INTERFACE is an interface name, with @@ -381,6 +407,10 @@ elif [[ $# -eq 2 && $1 == strip ]]; then auto_su parse_options "$2" cmd_strip +elif [[ $# -eq 2 && $1 == strip-and-eval ]]; then + auto_su + parse_options "$2" "unsafe" + cmd_strip else cmd_usage exit 1 -- 2.20.1
