[ptxdist] [PATCH 2/8] dropbear: Add ed25519 hostkey/public key support

[Alexander Dahl <ada@thorsis.com>]

This is supported by dropbear since version 2020.79, but was not used by
ptxdist yet.

Signed-off-by: Alexander Dahl <ada@thorsis.com>
---
 projectroot/etc/init.d/dropbear      |  3 +++
 projectroot/etc/rc.once.d/dropbear   |  3 +++
 projectroot/usr/lib/init/dropbear.sh |  1 +
 rules/dropbear.in                    | 12 ++++++++++++
 rules/dropbear.make                  | 11 +++++++++++
 5 files changed, 30 insertions(+)

diff --git a/projectroot/etc/init.d/dropbear b/projectroot/etc/init.d/dropbear
index 2039340b2..1b16de20a 100644
--- a/projectroot/etc/init.d/dropbear
+++ b/projectroot/etc/init.d/dropbear
@@ -25,6 +25,9 @@ dropbear_start() {
             ecdsa)
                 test -f "$DROPBEAR_ECDSAKEY" && KEY_ARGS="$KEY_ARGS -r $DROPBEAR_ECDSAKEY"
                 ;;
+            ed25519)
+                test -f "$DROPBEAR_ED25519KEY" && KEY_ARGS="$KEY_ARGS -r $DROPBEAR_ED25519KEY"
+                ;;
             *)
                 echo "Key type '$keytype' not supported"
                 ;;
diff --git a/projectroot/etc/rc.once.d/dropbear b/projectroot/etc/rc.once.d/dropbear
index a8725616a..191f6c61b 100644
--- a/projectroot/etc/rc.once.d/dropbear
+++ b/projectroot/etc/rc.once.d/dropbear
@@ -28,6 +28,9 @@ gen_keys() {
 			ecdsa)
 				gen_key ecdsa "$DROPBEAR_ECDSAKEY" || return
 				;;
+			ed25519)
+				gen_key ed25519 "$DROPBEAR_ED25519KEY" || return
+				;;
 			*)
 				echo "Key type '$keytype' not supported"
 				;;
diff --git a/projectroot/usr/lib/init/dropbear.sh b/projectroot/usr/lib/init/dropbear.sh
index 12fd6e5ce..aa375fe3c 100644
--- a/projectroot/usr/lib/init/dropbear.sh
+++ b/projectroot/usr/lib/init/dropbear.sh
@@ -2,4 +2,5 @@
 
 DROPBEAR_RSAKEY='@KEYDIR@/dropbear_rsa_host_key'
 DROPBEAR_ECDSAKEY='@KEYDIR@/dropbear_ecdsa_host_key'
+DROPBEAR_ED25519KEY='@KEYDIR@/dropbear_ed25519_host_key'
 DROPBEAR_KEYTYPES='@KEYTYPES@'
diff --git a/rules/dropbear.in b/rules/dropbear.in
index 553e0268c..a7698ba20 100644
--- a/rules/dropbear.in
+++ b/rules/dropbear.in
@@ -256,6 +256,18 @@ config DROPBEAR_ECDSA
 	  ECDSA stands for Elliptic Curve Digital Signature Algorithm.
 	  ECDSA is significantly faster than RSA.
 
+config DROPBEAR_ED25519
+	bool
+	prompt "ed25519"
+	default y
+	help
+	  Ed25519 is the EdDSA signature scheme using SHA-512 (SHA-2)
+	  and Curve25519.
+	  Ed25519 is intended to provide attack resistance comparable to
+	  quality 128-bit symmetric ciphers.
+	  Public keys are 256 bits long and signatures are 512 bits
+	  long.
+
 comment "Key exchange algorithm ---"
 
 config DROPBEAR_ECDH
diff --git a/rules/dropbear.make b/rules/dropbear.make
index 3a434e2c8..a5ff02c9e 100644
--- a/rules/dropbear.make
+++ b/rules/dropbear.make
@@ -202,6 +202,14 @@ else
 	@echo "#define DROPBEAR_ECDSA 0" >> $(DROPBEAR_LOCALOPTIONS)
 endif
 
+ifdef PTXCONF_DROPBEAR_ED25519
+	@echo "ptxdist: enabling ed25519"
+	@echo "#define DROPBEAR_ED25519 1" >> $(DROPBEAR_LOCALOPTIONS)
+else
+	@echo "ptxdist: disabling ed25519"
+	@echo "#define DROPBEAR_ED25519 0" >> $(DROPBEAR_LOCALOPTIONS)
+endif
+
 	@echo "ptxdist: disabling u2f security key support"
 	@echo "#define DROPBEAR_SK_ECDSA 0" >> $(DROPBEAR_LOCALOPTIONS)
 	@echo "#define DROPBEAR_SK_ED25519 0" >> $(DROPBEAR_LOCALOPTIONS)
@@ -263,6 +271,9 @@ endif
 ifdef PTXCONF_DROPBEAR_ECDSA
 DROPBEAR_KEY_TYPES	+= ecdsa
 endif
+ifdef PTXCONF_DROPBEAR_ED25519
+DROPBEAR_KEY_TYPES	+= ed25519
+endif
 
 $(STATEDIR)/dropbear.targetinstall:
 	@$(call targetinfo)
-- 
2.30.2