===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/ssh-rsa.c,v
retrieving revision 1.72
retrieving revision 1.73
diff -u -r1.72 -r1.73
--- src/usr.bin/ssh/ssh-rsa.c	2022/10/28 00:39:29	1.72
+++ src/usr.bin/ssh/ssh-rsa.c	2022/10/28 00:41:17	1.73
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-rsa.c,v 1.72 2022/10/28 00:39:29 djm Exp $ */
+/* $OpenBSD: ssh-rsa.c,v 1.73 2022/10/28 00:41:17 djm Exp $ */
 /*
  * Copyright (c) 2000, 2003 Markus Friedl <markus@openbsd.org>
  *
@@ -125,6 +125,32 @@
 	return ret;
 }
 
+static int
+ssh_rsa_copy_public(const struct sshkey *from, struct sshkey *to)
+{
+	const BIGNUM *rsa_n, *rsa_e;
+	BIGNUM *rsa_n_dup = NULL, *rsa_e_dup = NULL;
+	int r = SSH_ERR_INTERNAL_ERROR;
+
+	RSA_get0_key(from->rsa, &rsa_n, &rsa_e, NULL);
+	if ((rsa_n_dup = BN_dup(rsa_n)) == NULL ||
+	    (rsa_e_dup = BN_dup(rsa_e)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (!RSA_set0_key(to->rsa, rsa_n_dup, rsa_e_dup, NULL)) {
+		r = SSH_ERR_LIBCRYPTO_ERROR;
+		goto out;
+	}
+	rsa_n_dup = rsa_e_dup = NULL; /* transferred */
+	/* success */
+	r = 0;
+ out:
+	BN_clear_free(rsa_n_dup);
+	BN_clear_free(rsa_e_dup);
+	return r;
+}
+
 static const char *
 rsa_hash_alg_ident(int hash_alg)
 {
@@ -540,6 +566,7 @@
 	/* .equal = */		ssh_rsa_equal,
 	/* .ssh_serialize_public = */ ssh_rsa_serialize_public,
 	/* .generate = */	ssh_rsa_generate,
+	/* .copy_public = */	ssh_rsa_copy_public,
 };
 
 const struct sshkey_impl sshkey_rsa_impl = {