From 191f54fa2f3a7d4a6c69e00dd31bbd134870eea3 Mon Sep 17 00:00:00 2001
From: Jake <jake@weave.works>
Date: Thu, 24 Feb 2022 14:46:14 +0000
Subject: [PATCH] add support for ed25519 keys

---
 pkg/pki/sshkey.go      | 44 +++++++++++++++++-------------------------
 pkg/pki/sshkey_test.go | 12 ++++++------
 2 files changed, 24 insertions(+), 32 deletions(-)

diff --git a/pkg/pki/sshkey.go b/pkg/pki/sshkey.go
index 74b31b69bc5a0..a27879bf0cfea 100644
--- a/pkg/pki/sshkey.go
+++ b/pkg/pki/sshkey.go
@@ -73,13 +73,19 @@ func ComputeAWSKeyFingerprint(publicKey string) (string, error) {
 		return "", err
 	}
 
-	der, err := toDER(sshPublicKey)
-	if err != nil {
-		return "", fmt.Errorf("error computing fingerprint for SSH public key: %v", err)
+	switch fmt.Sprintf("%T", sshPublicKey) {
+	case "*ssh.rsaPublicKey":
+		der, err := rsaToDER(sshPublicKey)
+		if err != nil {
+			return "", fmt.Errorf("error computing fingerprint for SSH public key: %v", err)
+		}
+		h := md5.Sum(der)
+		return colonSeparatedHex(h[:]), nil
+	case "ssh.ed25519PublicKey":
+		return ssh.FingerprintSHA256(sshPublicKey), nil
 	}
-	h := md5.Sum(der)
 
-	return colonSeparatedHex(h[:]), nil
+	return "", fmt.Errorf("unexpected type of SSH key (%T); AWS can only import RSA and ed25519 keys", sshPublicKey)
 }
 
 // ComputeOpenSSHKeyFingerprint computes the OpenSSH fingerprint of the SSH public key
@@ -93,30 +99,16 @@ func ComputeOpenSSHKeyFingerprint(publicKey string) (string, error) {
 	return colonSeparatedHex(h[:]), nil
 }
 
-// toDER gets the DER encoding of the SSH public key
+// rsaToDER gets the DER encoding of the SSH public key
 // Annoyingly, the ssh code wraps the actual crypto keys, so we have to use reflection tricks
-func toDER(pubkey ssh.PublicKey) ([]byte, error) {
-	pubkeyValue := reflect.ValueOf(pubkey)
-	typeName := fmt.Sprintf("%T", pubkey)
-
+func rsaToDER(pubkey ssh.PublicKey) ([]byte, error) {
 	var cryptoKey crypto.PublicKey
-	switch typeName {
-	case "*ssh.rsaPublicKey":
-		var rsaPublicKey *rsa.PublicKey
-		targetType := reflect.ValueOf(rsaPublicKey).Type()
-		rsaPublicKey = pubkeyValue.Convert(targetType).Interface().(*rsa.PublicKey)
-		cryptoKey = rsaPublicKey
-
-	// case "*dsaPublicKey":
-	//	var dsaPublicKey *dsa.PublicKey
-	//	targetType := reflect.ValueOf(dsaPublicKey).Type()
-	//	dsaPublicKey = pubkeyValue.Convert(targetType).Interface().(*dsa.PublicKey)
-	//	cryptoKey = dsaPublicKey
-
-	default:
-		return nil, fmt.Errorf("unexpected type of SSH key (%q); AWS can only import RSA keys", typeName)
-	}
+	var rsaPublicKey *rsa.PublicKey
 
+	pubkeyValue := reflect.ValueOf(pubkey)
+	targetType := reflect.ValueOf(rsaPublicKey).Type()
+	rsaPublicKey = pubkeyValue.Convert(targetType).Interface().(*rsa.PublicKey)
+	cryptoKey = rsaPublicKey
 	der, err := x509.MarshalPKIXPublicKey(cryptoKey)
 	if err != nil {
 		return nil, fmt.Errorf("error marshaling SSH public key: %v", err)
diff --git a/pkg/pki/sshkey_test.go b/pkg/pki/sshkey_test.go
index 21b4ea676e2ec..36c081c7229cb 100644
--- a/pkg/pki/sshkey_test.go
+++ b/pkg/pki/sshkey_test.go
@@ -54,6 +54,11 @@ func Test_AWSFingerprint_RsaKeyEncrypted(t *testing.T) {
 	checkAWSFingerprintEqual(t, key, "c9:c5:05:5e:ea:54:fc:a4:7c:7c:75:5c:d2:71:5e:40")
 }
 
+func Test_AWSFingerprint_Ed25519Key(t *testing.T) {
+	key := "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBoB6Gtu8zPAPO1yF4OwysWUD8ZSEQYzMpOT0YvF9qJV user@example"
+	checkAWSFingerprintEqual(t, key, "SHA256:HvE7+gmH78VS53+iPuRDh/gKjVo26OzYU/qOnJWAgyk")
+}
+
 func Test_AWSFingerprint_TrickyWhitespace(t *testing.T) {
 	// No name, \r instead of whitespace
 	key := "ssh-rsa\rAAAAB3NzaC1yc2EAAAADAQABAAABAQCySdqIU+FhCWl3BNrAvPaOe5VfL2aCARUWwy91ZP+T7LBwFa9lhdttfjp/VX1D1/PVwntn2EhN079m8c2kfdmiZ/iCHqrLyIGSd+BOiCz0lT47znvANSfxYjLUuKrWWWeaXqerJkOsAD4PHchRLbZGPdbfoBKwtb/WT4GMRQmb9vmiaZYjsfdPPM9KkWI9ECoWFGjGehA8D+iYIPR711kRacb1xdYmnjHqxAZHFsb5L8wDWIeAyhy49cBD+lbzTiioq2xWLorXuFmXh6Do89PgzvHeyCLY6816f/kCX6wIFts8A2eaEHFL4rAOsuh6qHmSxGCR9peSyuRW8DxV725x\r"
@@ -62,12 +67,7 @@ func Test_AWSFingerprint_TrickyWhitespace(t *testing.T) {
 
 func Test_AWSFingerprint_DsaKey(t *testing.T) {
 	key := "ssh-dss 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 justin@machine"
-	checkAWSFingerprintError(t, key, "AWS can only import RSA keys")
-}
-
-func Test_AWSFingerprint_Ed25519Key(t *testing.T) {
-	key := "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFpyraYd4rUFftiEKzUO4wKFAgTkXxuJcRZwVcsuZJ8G justin@machine"
-	checkAWSFingerprintError(t, key, "AWS can only import RSA keys")
+	checkAWSFingerprintError(t, key, "AWS can only import RSA and ed25519 keys")
 }
 
 func checkOpenSSHFingerprintEqual(t *testing.T, publicKey string, fingerprint string) {