From ad73bac98f5c78f311da7a09da65b0c44363c88a Mon Sep 17 00:00:00 2001
From: Andrew Cady <d@jerkface.net>
Date: Fri, 7 Feb 2020 17:27:11 -0500
Subject: key-specific dyndns commands

---
 src/dyndns-command.sh                          | 59 ++++++++++++++++++++++++++
 src/dyndns.ecdsa-sha2-nistp256.cryptonomic.net |  1 +
 src/dyndns.ssh-dss.cryptonomic.net             |  1 +
 src/dyndns.ssh-ed25519.cryptonomic.net         |  1 +
 4 files changed, 62 insertions(+)
 create mode 100755 src/dyndns-command.sh
 create mode 120000 src/dyndns.ecdsa-sha2-nistp256.cryptonomic.net
 create mode 120000 src/dyndns.ssh-dss.cryptonomic.net
 create mode 120000 src/dyndns.ssh-ed25519.cryptonomic.net

diff --git a/src/dyndns-command.sh b/src/dyndns-command.sh
new file mode 100755
index 0000000..1061b31
--- /dev/null
+++ b/src/dyndns-command.sh
@@ -0,0 +1,59 @@
+#!/bin/bash
+subdomain=${SSH_REMOTE_FINGERPRINT//:/}
+ip_address=${SSH_CLIENT%% *}
+lan_address="$SSH_ORIGINAL_COMMAND"
+
+domain=ssh.cryptonomic.net 
+
+sqlescape()
+{
+	printf '%s' "'${1/\'/\'\'}'"
+}
+
+add()
+{
+	local newdomain="$(sqlescape "$1.$domain")" ip_address="$(sqlescape "$2")" domain="$(sqlescape "$domain")"
+
+	sqlite3 /etc/powerdns/powerdns.sqlite3 <<END
+BEGIN;
+	delete from records where type='A' and name=$newdomain;
+
+	insert into records
+
+		(domain_id,
+		name,
+		type,
+		content,
+		ttl,
+		prio)
+
+		select
+			id,
+			$newdomain,
+			'A',
+			$ip_address,
+			3600,
+			0
+		from domains
+		where name=$domain;
+COMMIT;
+END
+	if [ $? = 0 ]; then
+		printf '%s\n' "$1 $2"
+	fi
+}
+
+add "$subdomain" "$ip_address"
+
+set -- $lan_address
+while [ $# -ge 2 ]; do
+	d=$1
+	ip=$2
+	shift 2
+	
+	case "$d" in
+		*.*) continue;;
+	esac
+	
+	add "$d.$subdomain" "$ip"
+done
diff --git a/src/dyndns.ecdsa-sha2-nistp256.cryptonomic.net b/src/dyndns.ecdsa-sha2-nistp256.cryptonomic.net
new file mode 120000
index 0000000..e46be55
--- /dev/null
+++ b/src/dyndns.ecdsa-sha2-nistp256.cryptonomic.net
@@ -0,0 +1 @@
+dyndns.ssh-rsa.cryptonomic.net
\ No newline at end of file
diff --git a/src/dyndns.ssh-dss.cryptonomic.net b/src/dyndns.ssh-dss.cryptonomic.net
new file mode 120000
index 0000000..e46be55
--- /dev/null
+++ b/src/dyndns.ssh-dss.cryptonomic.net
@@ -0,0 +1 @@
+dyndns.ssh-rsa.cryptonomic.net
\ No newline at end of file
diff --git a/src/dyndns.ssh-ed25519.cryptonomic.net b/src/dyndns.ssh-ed25519.cryptonomic.net
new file mode 120000
index 0000000..e46be55
--- /dev/null
+++ b/src/dyndns.ssh-ed25519.cryptonomic.net
@@ -0,0 +1 @@
+dyndns.ssh-rsa.cryptonomic.net
\ No newline at end of file
-- 
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