From 71ad7c65189b9f8ff6226de297732257ba91040b Mon Sep 17 00:00:00 2001
From: djm <djm@openbsd.org>
Date: Wed, 11 Oct 2023 22:41:05 +0000
Subject: [PATCH] add support for reading ED25519 private keys in PEM PKCS8
 format; ok markus@ tb@

---
 usr.bin/ssh/sshkey.c | 37 +++++++++++++++++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/usr.bin/ssh/sshkey.c b/usr.bin/ssh/sshkey.c
index c3c3c513502..f41018c1872 100644
--- a/usr.bin/ssh/sshkey.c
+++ b/usr.bin/ssh/sshkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.c,v 1.138 2023/08/21 04:36:46 djm Exp $ */
+/* $OpenBSD: sshkey.c,v 1.139 2023/10/11 22:41:05 djm Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
@@ -3367,6 +3367,7 @@ sshkey_parse_private_pem_fileblob(struct sshbuf *blob, int type,
 	struct sshkey *prv = NULL;
 	BIO *bio = NULL;
 	int r;
+	size_t len;
 
 	if (keyp != NULL)
 		*keyp = NULL;
@@ -3442,6 +3443,39 @@ sshkey_parse_private_pem_fileblob(struct sshbuf *blob, int type,
 #ifdef DEBUG_PK
 		if (prv != NULL && prv->ecdsa != NULL)
 			sshkey_dump_ec_key(prv->ecdsa);
+#endif
+	} else if (EVP_PKEY_base_id(pk) == EVP_PKEY_ED25519 &&
+	    (type == KEY_UNSPEC || type == KEY_ED25519)) {
+		if ((prv = sshkey_new(KEY_UNSPEC)) == NULL ||
+		    (prv->ed25519_sk = calloc(1, ED25519_SK_SZ)) == NULL ||
+		    (prv->ed25519_pk = calloc(1, ED25519_PK_SZ)) == NULL) {
+			r = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+		prv->type = KEY_ED25519;
+		len = ED25519_PK_SZ;
+		if (!EVP_PKEY_get_raw_public_key(pk, prv->ed25519_pk, &len)) {
+			r = SSH_ERR_LIBCRYPTO_ERROR;
+			goto out;
+		}
+		if (len != ED25519_PK_SZ) {
+			r = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+		len = ED25519_SK_SZ - ED25519_PK_SZ;
+		if (!EVP_PKEY_get_raw_private_key(pk, prv->ed25519_sk, &len)) {
+			r = SSH_ERR_LIBCRYPTO_ERROR;
+			goto out;
+		}
+		if (len != ED25519_SK_SZ - ED25519_PK_SZ) {
+			r = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+		/* Append the public key to our private key */
+		memcpy(prv->ed25519_sk + (ED25519_SK_SZ - ED25519_PK_SZ),
+		    prv->ed25519_pk, ED25519_PK_SZ);
+#ifdef DEBUG_PK
+		sshbuf_dump_data(prv->ed25519_sk, ED25519_SK_SZ, stderr);
 #endif
 	} else {
 		r = SSH_ERR_INVALID_FORMAT;
@@ -3472,7 +3506,6 @@ sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
 		*commentp = NULL;
 
 	switch (type) {
-	case KEY_ED25519:
 	case KEY_XMSS:
 		/* No fallback for new-format-only keys */
 		return sshkey_parse_private2(blob, type, passphrase,
-- 
2.20.1