예제 #1
0
int
mm_answer_gss_checkmic(int sock, Buffer *m)
{
	gss_buffer_desc gssbuf, mic;
	OM_uint32 ret;
	u_int len;

	gssbuf.value = buffer_get_string(m, &len);
	gssbuf.length = len;
	mic.value = buffer_get_string(m, &len);
	mic.length = len;

	ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);

	xfree(gssbuf.value);
	xfree(mic.value);

	buffer_clear(m);
	buffer_put_int(m, ret);

	mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);

	if (!GSS_ERROR(ret))
		monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);

	return (0);
}
예제 #2
0
파일: auth2-gss.c 프로젝트: janetuk/openssh
/* 
 * The 'gssapi_keyex' userauth mechanism.
 */
static int
userauth_gsskeyex(Authctxt *authctxt)
{
	int authenticated = 0;
	Buffer b;
	gss_buffer_desc mic, gssbuf;
	u_int len;

	mic.value = packet_get_string(&len);
	mic.length = len;

	packet_check_eom();

	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
	    "gssapi-keyex");

	gssbuf.value = buffer_ptr(&b);
	gssbuf.length = buffer_len(&b);

	gssapi_set_username(authctxt);

	/* gss_kex_context is NULL with privsep, so we can't check it here */
	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context, 
	    &gssbuf, &mic))))
		authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
		    authctxt->pw));
	
	buffer_free(&b);
	xfree(mic.value);

	return (authenticated);
}
예제 #3
0
파일: monitor.c 프로젝트: djmdjm/libopenssh
int
mm_answer_gss_checkmic(int sock, struct sshbuf *m)
{
	gss_buffer_desc gssbuf, mic;
	OM_uint32 ret;
	size_t len;
	int r;
	u_char *p;

	if ((r = sshbuf_get_string(m, &p, &len)) != 0)
		fatal("%s: buffer error: %s", __func__, ssh_err(r));
	gssbuf.value = p;
	gssbuf.length = len;
	if ((r = sshbuf_get_string(m, &p, &len)) != 0)
		fatal("%s: buffer error: %s", __func__, ssh_err(r));
	mic.value = p;
	mic.length = len;

	ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);

	free(gssbuf.value);
	free(mic.value);

	sshbuf_reset(m);
	if ((r = sshbuf_put_u32(m, ret)) != 0)
		fatal("%s: buffer error: %s", __func__, ssh_err(r));

	mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);

	if (!GSS_ERROR(ret))
		monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);

	return 0;
}
예제 #4
0
static int
input_gssapi_mic(int type, u_int32_t plen, struct ssh *ssh)
{
	Authctxt *authctxt = ssh->authctxt;
	Gssctxt *gssctxt;
	int r, authenticated = 0;
	struct sshbuf *b;
	gss_buffer_desc mic, gssbuf;
	const char *displayname;
	u_char *p;
	size_t len;

	if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
		fatal("No authentication or GSSAPI context");

	gssctxt = authctxt->methoddata;

	if ((r = sshpkt_get_string(ssh, &p, &len)) != 0)
		fatal("%s: %s", __func__, ssh_err(r));
	if ((b = sshbuf_new()) == NULL)
		fatal("%s: sshbuf_new failed", __func__);
	mic.value = p;
	mic.length = len;
	ssh_gssapi_buildmic(b, authctxt->user, authctxt->service,
	    "gssapi-with-mic");

	if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
		fatal("%s: sshbuf_mutable_ptr failed", __func__);
	gssbuf.length = sshbuf_len(b);

	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
		authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	else
		logit("GSSAPI MIC check failed");

	sshbuf_free(b);
	free(mic.value);

	if ((!use_privsep || mm_is_monitor()) &&
	    (displayname = ssh_gssapi_displayname()) != NULL)
		auth2_record_info(authctxt, "%s", displayname);

	authctxt->postponed = 0;
	ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
	ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
	ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	userauth_finish(ssh, authenticated, "gssapi-with-mic", NULL);
	return 0;
}
예제 #5
0
static int
input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Gssctxt *gssctxt;
	int authenticated = 0;
	Buffer b;
	gss_buffer_desc mic, gssbuf;
	u_int len;

	if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
		fatal("No authentication or GSSAPI context");

	gssctxt = authctxt->methoddata;

	mic.value = packet_get_string(&len);
	mic.length = len;

	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
	    "gssapi-with-mic");

	gssbuf.value = buffer_ptr(&b);
	gssbuf.length = buffer_len(&b);

	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
		authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	else
		logit("GSSAPI MIC check failed");

	if (authenticated)
		authctxt->last_details = ssh_gssapi_get_displayname();

	buffer_free(&b);
	free(mic.value);

	authctxt->postponed = 0;
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	userauth_finish(authctxt, authenticated, "gssapi-with-mic", NULL);
	return 0;
}
예제 #6
0
파일: kexgssc.c 프로젝트: GarthSnyder/apple
void
kexgss_client(Kex *kex) {
	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	gss_buffer_desc recv_tok, gssbuf, msg_tok, *token_ptr;
	Gssctxt *ctxt;
	OM_uint32 maj_status, min_status, ret_flags;
	u_int klen, kout, slen = 0, hashlen, strlen;
	DH *dh; 
	BIGNUM *dh_server_pub = NULL;
	BIGNUM *shared_secret = NULL;
	BIGNUM *p = NULL;
	BIGNUM *g = NULL;	
	u_char *kbuf, *hash;
	u_char *serverhostkey = NULL;
	u_char *empty = "";
	char *msg;
	char *lang;
	int type = 0;
	int first = 1;
	int nbits = 0, min = DH_GRP_MIN, max = DH_GRP_MAX;

	/* Initialise our GSSAPI world */	
	ssh_gssapi_build_ctx(&ctxt);
	if (ssh_gssapi_id_kex(ctxt, kex->name, kex->kex_type) 
	    == GSS_C_NO_OID)
		fatal("Couldn't identify host exchange");

	if (ssh_gssapi_import_name(ctxt, kex->gss_host))
		fatal("Couldn't import hostname");

	if (kex->gss_client && 
	    ssh_gssapi_client_identity(ctxt, kex->gss_client))
		fatal("Couldn't acquire client credentials");

	switch (kex->kex_type) {
	case KEX_GSS_GRP1_SHA1:
		dh = dh_new_group1();
		break;
	case KEX_GSS_GRP14_SHA1:
		dh = dh_new_group14();
		break;
	case KEX_GSS_GEX_SHA1:
		debug("Doing group exchange\n");
		nbits = dh_estimate(kex->we_need * 8);
		packet_start(SSH2_MSG_KEXGSS_GROUPREQ);
		packet_put_int(min);
		packet_put_int(nbits);
		packet_put_int(max);

		packet_send();

		packet_read_expect(SSH2_MSG_KEXGSS_GROUP);

		if ((p = BN_new()) == NULL)
			fatal("BN_new() failed");
		packet_get_bignum2(p);
		if ((g = BN_new()) == NULL)
			fatal("BN_new() failed");
		packet_get_bignum2(g);
		packet_check_eom();

		if (BN_num_bits(p) < min || BN_num_bits(p) > max)
			fatal("GSSGRP_GEX group out of range: %d !< %d !< %d",
			    min, BN_num_bits(p), max);

		dh = dh_new_group(g, p);
		break;
	default:
		fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
	}
	
	/* Step 1 - e is dh->pub_key */
	dh_gen_key(dh, kex->we_need * 8);

	/* This is f, we initialise it now to make life easier */
	dh_server_pub = BN_new();
	if (dh_server_pub == NULL)
		fatal("dh_server_pub == NULL");

	token_ptr = GSS_C_NO_BUFFER;
			 
	do {
		debug("Calling gss_init_sec_context");
		
		maj_status = ssh_gssapi_init_ctx(ctxt,
		    kex->gss_deleg_creds, token_ptr, &send_tok,
		    &ret_flags);

		if (GSS_ERROR(maj_status)) {
			if (send_tok.length != 0) {
				packet_start(SSH2_MSG_KEXGSS_CONTINUE);
				packet_put_string(send_tok.value,
				    send_tok.length);
			}
			fatal("gss_init_context failed");
		}

		/* If we've got an old receive buffer get rid of it */
		if (token_ptr != GSS_C_NO_BUFFER)
			xfree(recv_tok.value);

		if (maj_status == GSS_S_COMPLETE) {
			/* If mutual state flag is not true, kex fails */
			if (!(ret_flags & GSS_C_MUTUAL_FLAG))
				fatal("Mutual authentication failed");

			/* If integ avail flag is not true kex fails */
			if (!(ret_flags & GSS_C_INTEG_FLAG))
				fatal("Integrity check failed");
		}

		/* 
		 * If we have data to send, then the last message that we
		 * received cannot have been a 'complete'. 
		 */
		if (send_tok.length != 0) {
			if (first) {
				packet_start(SSH2_MSG_KEXGSS_INIT);
				packet_put_string(send_tok.value,
				    send_tok.length);
				packet_put_bignum2(dh->pub_key);
				first = 0;
			} else {
				packet_start(SSH2_MSG_KEXGSS_CONTINUE);
				packet_put_string(send_tok.value,
				    send_tok.length);
			}
			packet_send();
			gss_release_buffer(&min_status, &send_tok);

			/* If we've sent them data, they should reply */
			do {	
				type = packet_read();
				if (type == SSH2_MSG_KEXGSS_HOSTKEY) {
					debug("Received KEXGSS_HOSTKEY");
					if (serverhostkey)
						fatal("Server host key received more than once");
					serverhostkey = 
					    packet_get_string(&slen);
				}
			} while (type == SSH2_MSG_KEXGSS_HOSTKEY);

			switch (type) {
			case SSH2_MSG_KEXGSS_CONTINUE:
				debug("Received GSSAPI_CONTINUE");
				if (maj_status == GSS_S_COMPLETE) 
					fatal("GSSAPI Continue received from server when complete");
				recv_tok.value = packet_get_string(&strlen);
				recv_tok.length = strlen; 
				break;
			case SSH2_MSG_KEXGSS_COMPLETE:
				debug("Received GSSAPI_COMPLETE");
				packet_get_bignum2(dh_server_pub);
				msg_tok.value =  packet_get_string(&strlen);
				msg_tok.length = strlen; 

				/* Is there a token included? */
				if (packet_get_char()) {
					recv_tok.value=
					    packet_get_string(&strlen);
					recv_tok.length = strlen;
					/* If we're already complete - protocol error */
					if (maj_status == GSS_S_COMPLETE)
						packet_disconnect("Protocol error: received token when complete");
					} else {
						/* No token included */
						if (maj_status != GSS_S_COMPLETE)
							packet_disconnect("Protocol error: did not receive final token");
				}
				break;
			case SSH2_MSG_KEXGSS_ERROR:
				debug("Received Error");
				maj_status = packet_get_int();
				min_status = packet_get_int();
				msg = packet_get_string(NULL);
				lang = packet_get_string(NULL);
				fatal("GSSAPI Error: \n%.400s",msg);
			default:
				packet_disconnect("Protocol error: didn't expect packet type %d",
		    		type);
			}
			token_ptr = &recv_tok;
		} else {
			/* No data, and not complete */
			if (maj_status != GSS_S_COMPLETE)
				fatal("Not complete, and no token output");
		}
	} while (maj_status & GSS_S_CONTINUE_NEEDED);

	/* 
	 * We _must_ have received a COMPLETE message in reply from the 
	 * server, which will have set dh_server_pub and msg_tok 
	 */

	if (type != SSH2_MSG_KEXGSS_COMPLETE)
		fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it");

	/* Check f in range [1, p-1] */
	if (!dh_pub_is_valid(dh, dh_server_pub))
		packet_disconnect("bad server public DH value");

	/* compute K=f^x mod p */
	klen = DH_size(dh);
	kbuf = xmalloc(klen);
	kout = DH_compute_key(kbuf, dh_server_pub, dh);
	if (kout < 0)
		fatal("DH_compute_key: failed");

	shared_secret = BN_new();
	if (shared_secret == NULL)
		fatal("kexgss_client: BN_new failed");

	if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
		fatal("kexdh_client: BN_bin2bn failed");

	memset(kbuf, 0, klen);
	xfree(kbuf);

	switch (kex->kex_type) {
	case KEX_GSS_GRP1_SHA1:
	case KEX_GSS_GRP14_SHA1:
		kex_dh_hash( kex->client_version_string, 
		    kex->server_version_string,
		    buffer_ptr(&kex->my), buffer_len(&kex->my),
		    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
		    (serverhostkey ? serverhostkey : empty), slen,
		    dh->pub_key,	/* e */
		    dh_server_pub,	/* f */
		    shared_secret,	/* K */
		    &hash, &hashlen
		);
		break;
	case KEX_GSS_GEX_SHA1:
		kexgex_hash(
		    kex->evp_md,
		    kex->client_version_string,
		    kex->server_version_string,
		    buffer_ptr(&kex->my), buffer_len(&kex->my),
		    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
		    (serverhostkey ? serverhostkey : empty), slen,
 		    min, nbits, max,
		    dh->p, dh->g,
		    dh->pub_key,
		    dh_server_pub,
		    shared_secret,
		    &hash, &hashlen
		);
		break;
	default:
		fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
	}

	gssbuf.value = hash;
	gssbuf.length = hashlen;

	/* Verify that the hash matches the MIC we just got. */
	if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok)))
		packet_disconnect("Hash's MIC didn't verify");

	xfree(msg_tok.value);

	DH_free(dh);
	if (serverhostkey)
		xfree(serverhostkey);
	BN_clear_free(dh_server_pub);

	/* save session id */
	if (kex->session_id == NULL) {
		kex->session_id_len = hashlen;
		kex->session_id = xmalloc(kex->session_id_len);
		memcpy(kex->session_id, hash, kex->session_id_len);
	}

	if (kex->gss_deleg_creds)
		ssh_gssapi_credentials_updated(ctxt);

	if (gss_kex_context == NULL)
		gss_kex_context = ctxt;
	else
		ssh_gssapi_delete_ctx(&ctxt);

	kex_derive_keys(kex, hash, hashlen, shared_secret);
	BN_clear_free(shared_secret);
	kex_finish(kex);
}