Attachment #3559 for bug #3375




		free(ext);
	}

	/* Check whether client supports rsa-sha2 algorithms */
	if (kex->server && (kex->flags & KEX_INITIAL)) {
		char *ext;

		ext = match_list("rsa-sha2-256", peer[PROPOSAL_SERVER_HOST_KEY_ALGS], NULL);
		if (ext) {
			kex->flags |= KEX_RSA_SHA2_256_SUPPORTED;
			free(ext);
		}

		ext = match_list("rsa-sha2-512", peer[PROPOSAL_SERVER_HOST_KEY_ALGS], NULL);
		if (ext) {
			kex->flags |= KEX_RSA_SHA2_512_SUPPORTED;
			free(ext);
		}

		ext = match_list("rsa-sha2-256-cert-v01@openssh.com", peer[PROPOSAL_SERVER_HOST_KEY_ALGS], NULL);
		if (ext) {
			kex->flags |= KEX_RSA_SHA2_256_SUPPORTED;
			free(ext);
		}

		ext = match_list("rsa-sha2-512-cert-v01@openssh.com", peer[PROPOSAL_SERVER_HOST_KEY_ALGS], NULL);
		if (ext) {
			kex->flags |= KEX_RSA_SHA2_512_SUPPORTED;
			free(ext);
		}
	}

	/* Algorithm Negotiation */
	if ((r = choose_kex(kex, cprop[PROPOSAL_KEX_ALGS],
	    sprop[PROPOSAL_KEX_ALGS])) != 0) {

Lines 109-114 enum kex_exchange { Link Here

(-)a/kex.h (+2 lines)
109	#define KEX_INIT_SENT 0x0001	109	#define KEX_INIT_SENT 0x0001
110	#define KEX_INITIAL 0x0002	110	#define KEX_INITIAL 0x0002
111	#define KEX_HAS_PUBKEY_HOSTBOUND 0x0004	111	#define KEX_HAS_PUBKEY_HOSTBOUND 0x0004
		112	#define KEX_RSA_SHA2_256_SUPPORTED 0x0008
		113	#define KEX_RSA_SHA2_512_SUPPORTED 0x0010
112		114
113	struct sshenc {	115	struct sshenc {
114	char *name;	116	char *name;

Lines 684-690 server_input_hostkeys_prove(struct ssh ssh, struct sshbuf *respp) Link Here

(-)a/serverloop.c (-6 / +13 lines)
684	struct sshbuf *resp = NULL;	684	struct sshbuf *resp = NULL;
685	struct sshbuf *sigbuf = NULL;	685	struct sshbuf *sigbuf = NULL;
686	struct sshkey key = NULL, key_pub = NULL, *key_prv = NULL;	686	struct sshkey key = NULL, key_pub = NULL, *key_prv = NULL;
687	int r, ndx, kexsigtype, use_kexsigtype, success = 0;	687	int r, ndx, success = 0;
688	const u_char *blob;	688	const u_char *blob;
689	u_char *sig = 0;	689	u_char *sig = 0;
690	size_t blen, slen;	690	size_t blen, slen;
Lines 692-700 server_input_hostkeys_prove(struct ssh ssh, struct sshbuf *respp) Link Here
692	if ((resp = sshbuf_new()) == NULL \|\| (sigbuf = sshbuf_new()) == NULL)	692	if ((resp = sshbuf_new()) == NULL \|\| (sigbuf = sshbuf_new()) == NULL)
693	fatal_f("sshbuf_new");	693	fatal_f("sshbuf_new");
694		694
695	kexsigtype = sshkey_type_plain(
696	sshkey_type_from_name(ssh->kex->hostkey_alg));
697	while (ssh_packet_remaining(ssh) > 0) {	695	while (ssh_packet_remaining(ssh) > 0) {
		696	const char *pkexstr = NULL;
		697	const char *rsa_sha2_256 = "rsa-sha2-256";
		698	const char *rsa_sha2_512 = "rsa-sha2-512";
		699
698	sshkey_free(key);	700	sshkey_free(key);
699	key = NULL;	701	key = NULL;
700	if ((r = sshpkt_get_string_direct(ssh, &blob, &blen)) != 0 \|\|	702	if ((r = sshpkt_get_string_direct(ssh, &blob, &blen)) != 0 \|\|
Lines 726-733 server_input_hostkeys_prove(struct ssh ssh, struct sshbuf *respp) Link Here
726	* For RSA keys, prefer to use the signature type negotiated	728	* For RSA keys, prefer to use the signature type negotiated
727	* during KEX to the default (SHA1).	729	* during KEX to the default (SHA1).
728	*/	730	*/
729	use_kexsigtype = kexsigtype == KEY_RSA &&	731	if (sshkey_type_plain(key->type) == KEY_RSA) {
730	sshkey_type_plain(key->type) == KEY_RSA;	732	if (ssh->kex->flags & KEX_RSA_SHA2_512_SUPPORTED)
		733	pkexstr = rsa_sha2_512;
		734	else if (ssh->kex->flags & KEX_RSA_SHA2_256_SUPPORTED)
		735	pkexstr = rsa_sha2_256;
		736	}
		737
731	if ((r = sshbuf_put_cstring(sigbuf,	738	if ((r = sshbuf_put_cstring(sigbuf,
732	"hostkeys-prove-00@openssh.com")) != 0 \|\|	739	"hostkeys-prove-00@openssh.com")) != 0 \|\|
733	(r = sshbuf_put_stringb(sigbuf,	740	(r = sshbuf_put_stringb(sigbuf,
Lines 735-741 server_input_hostkeys_prove(struct ssh ssh, struct sshbuf *respp) Link Here
735	(r = sshkey_puts(key, sigbuf)) != 0 \|\|	742	(r = sshkey_puts(key, sigbuf)) != 0 \|\|
736	(r = ssh->kex->sign(ssh, key_prv, key_pub, &sig, &slen,	743	(r = ssh->kex->sign(ssh, key_prv, key_pub, &sig, &slen,
737	sshbuf_ptr(sigbuf), sshbuf_len(sigbuf),	744	sshbuf_ptr(sigbuf), sshbuf_len(sigbuf),
738	use_kexsigtype ? ssh->kex->hostkey_alg : NULL)) != 0 \|\|	745	pkexstr)) != 0 \|\|
739	(r = sshbuf_put_string(resp, sig, slen)) != 0) {	746	(r = sshbuf_put_string(resp, sig, slen)) != 0) {
740	error_fr(r, "assemble signature");	747	error_fr(r, "assemble signature");
741	goto out;	748	goto out;

Return to bug 3375

Lines 935-940 kex_choose_conf(struct ssh *ssh) Link Here

(-)a/kex.c (+29 lines)
935	free(ext);	935	free(ext);
936	}	936	}
937		937
		938	/* Check whether client supports rsa-sha2 algorithms */
		939	if (kex->server && (kex->flags & KEX_INITIAL)) {
		940	char *ext;
		941
		942	ext = match_list("rsa-sha2-256", peer[PROPOSAL_SERVER_HOST_KEY_ALGS], NULL);
		943	if (ext) {
		944	kex->flags \|= KEX_RSA_SHA2_256_SUPPORTED;
		945	free(ext);
		946	}
		947
		948	ext = match_list("rsa-sha2-512", peer[PROPOSAL_SERVER_HOST_KEY_ALGS], NULL);
		949	if (ext) {
		950	kex->flags \|= KEX_RSA_SHA2_512_SUPPORTED;
		951	free(ext);
		952	}
		953
		954	ext = match_list("rsa-sha2-256-cert-v01@openssh.com", peer[PROPOSAL_SERVER_HOST_KEY_ALGS], NULL);
		955	if (ext) {
		956	kex->flags \|= KEX_RSA_SHA2_256_SUPPORTED;
		957	free(ext);
		958	}
		959
		960	ext = match_list("rsa-sha2-512-cert-v01@openssh.com", peer[PROPOSAL_SERVER_HOST_KEY_ALGS], NULL);
		961	if (ext) {
		962	kex->flags \|= KEX_RSA_SHA2_512_SUPPORTED;
		963	free(ext);
		964	}
		965	}
		966
938	/* Algorithm Negotiation */	967	/* Algorithm Negotiation */
939	if ((r = choose_kex(kex, cprop[PROPOSAL_KEX_ALGS],	968	if ((r = choose_kex(kex, cprop[PROPOSAL_KEX_ALGS],
940	sprop[PROPOSAL_KEX_ALGS])) != 0) {	969	sprop[PROPOSAL_KEX_ALGS])) != 0) {