upstream: refactor sshkey_from_blob_internal()

feedback/ok markus@

OpenBSD-Commit-ID: 1f46c0cbb8060ee9666a02749594ad6658c8e283

1 files changed, 36 insertions, 4 deletions

diff --git a/ssh-xmss.c b/ssh-xmss.c
index ef0fed167..039436b43 100644
--- a/ssh-xmss.c
+++ b/ssh-xmss.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-xmss.c,v 1.10 2022/10/28 00:41:17 djm Exp $*/
+/* $OpenBSD: ssh-xmss.c,v 1.11 2022/10/28 00:41:52 djm Exp $*/
 /*
  * Copyright (c) 2017 Stefan-Lukas Gazdag.
  * Copyright (c) 2017 Markus Friedl.
@@ -65,15 +65,14 @@ ssh_xmss_equal(const struct sshkey *a, const struct sshkey *b)
 
 static int
 ssh_xmss_serialize_public(const struct sshkey *key, struct sshbuf *b,
-    const char *typename, enum sshkey_serialize_rep opts)
+    enum sshkey_serialize_rep opts)
 {
 	int r;
 
 	if (key->xmss_name == NULL || key->xmss_pk == NULL ||
 	    sshkey_xmss_pklen(key) == 0)
 		return SSH_ERR_INVALID_ARGUMENT;
-	if ((r = sshbuf_put_cstring(b, typename)) != 0 ||
-	    (r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
+	if ((r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
 	    (r = sshbuf_put_string(b, key->xmss_pk,
 	    sshkey_xmss_pklen(key))) != 0 ||
 	    (r = sshkey_xmss_serialize_pk_info(key, b, opts)) != 0)
@@ -107,6 +106,38 @@ ssh_xmss_copy_public(const struct sshkey *from, struct sshkey *to)
 	return 0;
 }
 
+static int
+ssh_xmss_deserialize_public(const char *ktype, struct sshbuf *b,
+    struct sshkey *key)
+{
+	size_t len = 0;
+	char *xmss_name = NULL;
+	u_char *pk = NULL;
+	int ret = SSH_ERR_INTERNAL_ERROR;
+
+	if ((ret = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0)
+		goto out;
+	if ((ret = sshkey_xmss_init(key, xmss_name)) != 0)
+		goto out;
+	if ((ret = sshbuf_get_string(b, &pk, &len)) != 0)
+		goto out;
+	if (len == 0 || len != sshkey_xmss_pklen(key)) {
+		ret = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+	key->xmss_pk = pk;
+	pk = NULL;
+	if (!sshkey_is_cert(key) &&
+	    (ret = sshkey_xmss_deserialize_pk_info(key, b)) != 0)
+		goto out;
+	/* success */
+	ret = 0;
+ out:
+	free(xmss_name);
+	freezero(pk, len);
+	return ret;
+}
+
 int
 ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
     const u_char *data, size_t datalen, u_int compat)
@@ -261,6 +292,7 @@ static const struct sshkey_impl_funcs sshkey_xmss_funcs = {
 	/* .cleanup = */	ssh_xmss_cleanup,
 	/* .equal = */		ssh_xmss_equal,
 	/* .ssh_serialize_public = */ ssh_xmss_serialize_public,
+	/* .ssh_deserialize_public = */ ssh_xmss_deserialize_public,
 	/* .generate = */	sshkey_xmss_generate_private_key,
 	/* .copy_public = */	ssh_xmss_copy_public,
 };