upstream: refactor and simplify sshkey_read()

feedback/ok markus@

OpenBSD-Commit-ID: 0d93b7a56e31cd06a8bb0d2191d084ce254b0971

1 files changed, 24 insertions, 122 deletions

diff --git a/sshkey.c b/sshkey.c
index b4130f2a..31419299 100644
--- a/sshkey.c
+++ b/sshkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.c,v 1.125 2022/10/28 00:37:24 djm Exp $ */
+/* $OpenBSD: sshkey.c,v 1.126 2022/10/28 00:38:58 djm Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
@@ -192,12 +192,20 @@ sshkey_impl_from_type_nid(int type, int nid)
 	return NULL;
 }
 
+static const struct sshkey_impl *
+sshkey_impl_from_key(const struct sshkey *k)
+{
+	if (k == NULL)
+		return NULL;
+	return sshkey_impl_from_type_nid(k->type, k->ecdsa_nid);
+}
+
 const char *
 sshkey_type(const struct sshkey *k)
 {
 	const struct sshkey_impl *impl;
 
-	if ((impl = sshkey_impl_from_type(k->type)) == NULL)
+	if ((impl = sshkey_impl_from_key(k)) == NULL)
 		return "unknown";
 	return impl->shortname;
 }
@@ -376,7 +384,7 @@ sshkey_size(const struct sshkey *k)
 {
 	const struct sshkey_impl *impl;
 
-	if ((impl = sshkey_impl_from_type_nid(k->type, k->ecdsa_nid)) == NULL)
+	if ((impl = sshkey_impl_from_key(k)) == NULL)
 		return 0;
 	if (impl->funcs->size != NULL)
 		return impl->funcs->size(k);
@@ -607,8 +615,8 @@ sshkey_sk_cleanup(struct sshkey *k)
 	k->sk_key_handle = k->sk_reserved = NULL;
 }
 
-void
-sshkey_free(struct sshkey *k)
+static void
+sshkey_free_contents(struct sshkey *k)
 {
 	const struct sshkey_impl *impl;
 
@@ -624,6 +632,13 @@ sshkey_free(struct sshkey *k)
 	freezero(k, sizeof(*k));
 }
 
+void
+sshkey_free(struct sshkey *k)
+{
+	sshkey_free_contents(k);
+	freezero(k, sizeof(*k));
+}
+
 static int
 cert_compare(struct sshkey_cert *a, struct sshkey_cert *b)
 {
@@ -1134,29 +1149,8 @@ sshkey_read(struct sshkey *ret, char **cpp)
 
 	if (ret == NULL)
 		return SSH_ERR_INVALID_ARGUMENT;
-
-	switch (ret->type) {
-	case KEY_UNSPEC:
-	case KEY_RSA:
-	case KEY_DSA:
-	case KEY_ECDSA:
-	case KEY_ECDSA_SK:
-	case KEY_ED25519:
-	case KEY_ED25519_SK:
-	case KEY_DSA_CERT:
-	case KEY_ECDSA_CERT:
-	case KEY_ECDSA_SK_CERT:
-	case KEY_RSA_CERT:
-	case KEY_ED25519_CERT:
-	case KEY_ED25519_SK_CERT:
-#ifdef WITH_XMSS
-	case KEY_XMSS:
-	case KEY_XMSS_CERT:
-#endif /* WITH_XMSS */
-		break; /* ok */
-	default:
+	if (ret->type != KEY_UNSPEC && sshkey_impl_from_type(ret->type) == NULL)
 		return SSH_ERR_INVALID_ARGUMENT;
-	}
 
 	/* Decode type */
 	cp = *cpp;
@@ -1209,107 +1203,15 @@ sshkey_read(struct sshkey *ret, char **cpp)
 	}
 
 	/* Fill in ret from parsed key */
-	ret->type = type;
-	if (sshkey_is_cert(ret)) {
-		if (!sshkey_is_cert(k)) {
-			sshkey_free(k);
-			return SSH_ERR_EXPECTED_CERT;
-		}
-		if (ret->cert != NULL)
-			cert_free(ret->cert);
-		ret->cert = k->cert;
-		k->cert = NULL;
-	}
-	switch (sshkey_type_plain(ret->type)) {
-#ifdef WITH_OPENSSL
-	case KEY_RSA:
-		RSA_free(ret->rsa);
-		ret->rsa = k->rsa;
-		k->rsa = NULL;
-#ifdef DEBUG_PK
-		RSA_print_fp(stderr, ret->rsa, 8);
-#endif
-		break;
-	case KEY_DSA:
-		DSA_free(ret->dsa);
-		ret->dsa = k->dsa;
-		k->dsa = NULL;
-#ifdef DEBUG_PK
-		DSA_print_fp(stderr, ret->dsa, 8);
-#endif
-		break;
-# ifdef OPENSSL_HAS_ECC
-	case KEY_ECDSA:
-		EC_KEY_free(ret->ecdsa);
-		ret->ecdsa = k->ecdsa;
-		ret->ecdsa_nid = k->ecdsa_nid;
-		k->ecdsa = NULL;
-		k->ecdsa_nid = -1;
-#ifdef DEBUG_PK
-		sshkey_dump_ec_key(ret->ecdsa);
-#endif
-		break;
-	case KEY_ECDSA_SK:
-		EC_KEY_free(ret->ecdsa);
-		ret->ecdsa = k->ecdsa;
-		ret->ecdsa_nid = k->ecdsa_nid;
-		ret->sk_application = k->sk_application;
-		k->ecdsa = NULL;
-		k->ecdsa_nid = -1;
-		k->sk_application = NULL;
-#ifdef DEBUG_PK
-		sshkey_dump_ec_key(ret->ecdsa);
-		fprintf(stderr, "App: %s\n", ret->sk_application);
-#endif
-		break;
-# endif /* OPENSSL_HAS_ECC */
-#endif /* WITH_OPENSSL */
-	case KEY_ED25519:
-		freezero(ret->ed25519_pk, ED25519_PK_SZ);
-		ret->ed25519_pk = k->ed25519_pk;
-		k->ed25519_pk = NULL;
-#ifdef DEBUG_PK
-		/* XXX */
-#endif
-		break;
-	case KEY_ED25519_SK:
-		freezero(ret->ed25519_pk, ED25519_PK_SZ);
-		ret->ed25519_pk = k->ed25519_pk;
-		ret->sk_application = k->sk_application;
-		k->ed25519_pk = NULL;
-		k->sk_application = NULL;
-		break;
-#ifdef WITH_XMSS
-	case KEY_XMSS:
-		free(ret->xmss_pk);
-		ret->xmss_pk = k->xmss_pk;
-		k->xmss_pk = NULL;
-		free(ret->xmss_state);
-		ret->xmss_state = k->xmss_state;
-		k->xmss_state = NULL;
-		free(ret->xmss_name);
-		ret->xmss_name = k->xmss_name;
-		k->xmss_name = NULL;
-		free(ret->xmss_filename);
-		ret->xmss_filename = k->xmss_filename;
-		k->xmss_filename = NULL;
-#ifdef DEBUG_PK
-		/* XXX */
-#endif
-		break;
-#endif /* WITH_XMSS */
-	default:
-		sshkey_free(k);
-		return SSH_ERR_INTERNAL_ERROR;
-	}
-	sshkey_free(k);
+	sshkey_free_contents(ret);
+	*ret = *k;
+	freezero(k, sizeof(*k));
 
 	/* success */
 	*cpp = cp;
 	return 0;
 }
 
-
 int
 sshkey_to_base64(const struct sshkey *key, char **b64p)
 {