Put ssh back into the repository
Change-Id: I23324372188fa6ed3f93a32b84365f5df6367590
diff --git a/authfd.c b/authfd.c
new file mode 100644
index 0000000..f037e83
--- /dev/null
+++ b/authfd.c
@@ -0,0 +1,708 @@
+/* $OpenBSD: authfd.c,v 1.86 2011/07/06 18:09:21 tedu Exp $ */
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ * Functions for connecting the local authentication agent.
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ * SSH2 implementation,
+ * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+
+#include <openssl/evp.h>
+
+#include <openssl/crypto.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "xmalloc.h"
+#include "ssh.h"
+#include "rsa.h"
+#include "buffer.h"
+#include "key.h"
+#include "authfd.h"
+#include "cipher.h"
+#include "kex.h"
+#include "compat.h"
+#include "log.h"
+#include "atomicio.h"
+#include "misc.h"
+
+static int agent_present = 0;
+
+/* helper */
+int decode_reply(int type);
+
+/* macro to check for "agent failure" message */
+#define agent_failed(x) \
+ ((x == SSH_AGENT_FAILURE) || (x == SSH_COM_AGENT2_FAILURE) || \
+ (x == SSH2_AGENT_FAILURE))
+
+int
+ssh_agent_present(void)
+{
+ int authfd;
+
+ if (agent_present)
+ return 1;
+ if ((authfd = ssh_get_authentication_socket()) == -1)
+ return 0;
+ else {
+ ssh_close_authentication_socket(authfd);
+ return 1;
+ }
+}
+
+/* Returns the number of the authentication fd, or -1 if there is none. */
+
+int
+ssh_get_authentication_socket(void)
+{
+ const char *authsocket;
+ int sock;
+ struct sockaddr_un sunaddr;
+
+ authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
+ if (!authsocket)
+ return -1;
+
+ bzero(&sunaddr, sizeof(sunaddr));
+ sunaddr.sun_family = AF_UNIX;
+ strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
+
+ sock = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (sock < 0)
+ return -1;
+
+ /* close on exec */
+ if (fcntl(sock, F_SETFD, FD_CLOEXEC) == -1) {
+ close(sock);
+ return -1;
+ }
+ if (connect(sock, (struct sockaddr *)&sunaddr, sizeof sunaddr) < 0) {
+ close(sock);
+ return -1;
+ }
+ agent_present = 1;
+ return sock;
+}
+
+static int
+ssh_request_reply(AuthenticationConnection *auth, Buffer *request, Buffer *reply)
+{
+ u_int l, len;
+ char buf[1024];
+
+ /* Get the length of the message, and format it in the buffer. */
+ len = buffer_len(request);
+ put_u32(buf, len);
+
+ /* Send the length and then the packet to the agent. */
+ if (atomicio(vwrite, auth->fd, buf, 4) != 4 ||
+ atomicio(vwrite, auth->fd, buffer_ptr(request),
+ buffer_len(request)) != buffer_len(request)) {
+ error("Error writing to authentication socket.");
+ return 0;
+ }
+ /*
+ * Wait for response from the agent. First read the length of the
+ * response packet.
+ */
+ if (atomicio(read, auth->fd, buf, 4) != 4) {
+ error("Error reading response length from authentication socket.");
+ return 0;
+ }
+
+ /* Extract the length, and check it for sanity. */
+ len = get_u32(buf);
+ if (len > 256 * 1024)
+ fatal("Authentication response too long: %u", len);
+
+ /* Read the rest of the response in to the buffer. */
+ buffer_clear(reply);
+ while (len > 0) {
+ l = len;
+ if (l > sizeof(buf))
+ l = sizeof(buf);
+ if (atomicio(read, auth->fd, buf, l) != l) {
+ error("Error reading response from authentication socket.");
+ return 0;
+ }
+ buffer_append(reply, buf, l);
+ len -= l;
+ }
+ return 1;
+}
+
+/*
+ * Closes the agent socket if it should be closed (depends on how it was
+ * obtained). The argument must have been returned by
+ * ssh_get_authentication_socket().
+ */
+
+void
+ssh_close_authentication_socket(int sock)
+{
+ if (getenv(SSH_AUTHSOCKET_ENV_NAME))
+ close(sock);
+}
+
+/*
+ * Opens and connects a private socket for communication with the
+ * authentication agent. Returns the file descriptor (which must be
+ * shut down and closed by the caller when no longer needed).
+ * Returns NULL if an error occurred and the connection could not be
+ * opened.
+ */
+
+AuthenticationConnection *
+ssh_get_authentication_connection(void)
+{
+ AuthenticationConnection *auth;
+ int sock;
+
+ sock = ssh_get_authentication_socket();
+
+ /*
+ * Fail if we couldn't obtain a connection. This happens if we
+ * exited due to a timeout.
+ */
+ if (sock < 0)
+ return NULL;
+
+ auth = xmalloc(sizeof(*auth));
+ auth->fd = sock;
+ buffer_init(&auth->identities);
+ auth->howmany = 0;
+
+ return auth;
+}
+
+/*
+ * Closes the connection to the authentication agent and frees any associated
+ * memory.
+ */
+
+void
+ssh_close_authentication_connection(AuthenticationConnection *auth)
+{
+ buffer_free(&auth->identities);
+ close(auth->fd);
+ xfree(auth);
+}
+
+/* Lock/unlock agent */
+int
+ssh_lock_agent(AuthenticationConnection *auth, int lock, const char *password)
+{
+ int type;
+ Buffer msg;
+
+ buffer_init(&msg);
+ buffer_put_char(&msg, lock ? SSH_AGENTC_LOCK : SSH_AGENTC_UNLOCK);
+ buffer_put_cstring(&msg, password);
+
+ if (ssh_request_reply(auth, &msg, &msg) == 0) {
+ buffer_free(&msg);
+ return 0;
+ }
+ type = buffer_get_char(&msg);
+ buffer_free(&msg);
+ return decode_reply(type);
+}
+
+/*
+ * Returns the first authentication identity held by the agent.
+ */
+
+int
+ssh_get_num_identities(AuthenticationConnection *auth, int version)
+{
+ int type, code1 = 0, code2 = 0;
+ Buffer request;
+
+ switch (version) {
+ case 1:
+ code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
+ code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
+ break;
+ case 2:
+ code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
+ code2 = SSH2_AGENT_IDENTITIES_ANSWER;
+ break;
+ default:
+ return 0;
+ }
+
+ /*
+ * Send a message to the agent requesting for a list of the
+ * identities it can represent.
+ */
+ buffer_init(&request);
+ buffer_put_char(&request, code1);
+
+ buffer_clear(&auth->identities);
+ if (ssh_request_reply(auth, &request, &auth->identities) == 0) {
+ buffer_free(&request);
+ return 0;
+ }
+ buffer_free(&request);
+
+ /* Get message type, and verify that we got a proper answer. */
+ type = buffer_get_char(&auth->identities);
+ if (agent_failed(type)) {
+ return 0;
+ } else if (type != code2) {
+ fatal("Bad authentication reply message type: %d", type);
+ }
+
+ /* Get the number of entries in the response and check it for sanity. */
+ auth->howmany = buffer_get_int(&auth->identities);
+ if ((u_int)auth->howmany > 1024)
+ fatal("Too many identities in authentication reply: %d",
+ auth->howmany);
+
+ return auth->howmany;
+}
+
+Key *
+ssh_get_first_identity(AuthenticationConnection *auth, char **comment, int version)
+{
+ /* get number of identities and return the first entry (if any). */
+ if (ssh_get_num_identities(auth, version) > 0)
+ return ssh_get_next_identity(auth, comment, version);
+ return NULL;
+}
+
+Key *
+ssh_get_next_identity(AuthenticationConnection *auth, char **comment, int version)
+{
+ int keybits;
+ u_int bits;
+ u_char *blob;
+ u_int blen;
+ Key *key = NULL;
+
+ /* Return failure if no more entries. */
+ if (auth->howmany <= 0)
+ return NULL;
+
+ /*
+ * Get the next entry from the packet. These will abort with a fatal
+ * error if the packet is too short or contains corrupt data.
+ */
+ switch (version) {
+ case 1:
+ key = key_new(KEY_RSA1);
+ bits = buffer_get_int(&auth->identities);
+ buffer_get_bignum(&auth->identities, key->rsa->e);
+ buffer_get_bignum(&auth->identities, key->rsa->n);
+ *comment = buffer_get_string(&auth->identities, NULL);
+ keybits = BN_num_bits(key->rsa->n);
+ if (keybits < 0 || bits != (u_int)keybits)
+ logit("Warning: identity keysize mismatch: actual %d, announced %u",
+ BN_num_bits(key->rsa->n), bits);
+ break;
+ case 2:
+ blob = buffer_get_string(&auth->identities, &blen);
+ *comment = buffer_get_string(&auth->identities, NULL);
+ key = key_from_blob(blob, blen);
+ xfree(blob);
+ break;
+ default:
+ return NULL;
+ }
+ /* Decrement the number of remaining entries. */
+ auth->howmany--;
+ return key;
+}
+
+/*
+ * Generates a random challenge, sends it to the agent, and waits for
+ * response from the agent. Returns true (non-zero) if the agent gave the
+ * correct answer, zero otherwise. Response type selects the style of
+ * response desired, with 0 corresponding to protocol version 1.0 (no longer
+ * supported) and 1 corresponding to protocol version 1.1.
+ */
+
+int
+ssh_decrypt_challenge(AuthenticationConnection *auth,
+ Key* key, BIGNUM *challenge,
+ u_char session_id[16],
+ u_int response_type,
+ u_char response[16])
+{
+ Buffer buffer;
+ int success = 0;
+ int i;
+ int type;
+
+ if (key->type != KEY_RSA1)
+ return 0;
+ if (response_type == 0) {
+ logit("Compatibility with ssh protocol version 1.0 no longer supported.");
+ return 0;
+ }
+ buffer_init(&buffer);
+ buffer_put_char(&buffer, SSH_AGENTC_RSA_CHALLENGE);
+ buffer_put_int(&buffer, BN_num_bits(key->rsa->n));
+ buffer_put_bignum(&buffer, key->rsa->e);
+ buffer_put_bignum(&buffer, key->rsa->n);
+ buffer_put_bignum(&buffer, challenge);
+ buffer_append(&buffer, session_id, 16);
+ buffer_put_int(&buffer, response_type);
+
+ if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
+ buffer_free(&buffer);
+ return 0;
+ }
+ type = buffer_get_char(&buffer);
+
+ if (agent_failed(type)) {
+ logit("Agent admitted failure to authenticate using the key.");
+ } else if (type != SSH_AGENT_RSA_RESPONSE) {
+ fatal("Bad authentication response: %d", type);
+ } else {
+ success = 1;
+ /*
+ * Get the response from the packet. This will abort with a
+ * fatal error if the packet is corrupt.
+ */
+ for (i = 0; i < 16; i++)
+ response[i] = (u_char)buffer_get_char(&buffer);
+ }
+ buffer_free(&buffer);
+ return success;
+}
+
+/* ask agent to sign data, returns -1 on error, 0 on success */
+int
+ssh_agent_sign(AuthenticationConnection *auth,
+ Key *key,
+ u_char **sigp, u_int *lenp,
+ u_char *data, u_int datalen)
+{
+ extern int datafellows;
+ Buffer msg;
+ u_char *blob;
+ u_int blen;
+ int type, flags = 0;
+ int ret = -1;
+
+ if (key_to_blob(key, &blob, &blen) == 0)
+ return -1;
+
+ if (datafellows & SSH_BUG_SIGBLOB)
+ flags = SSH_AGENT_OLD_SIGNATURE;
+
+ buffer_init(&msg);
+ buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST);
+ buffer_put_string(&msg, blob, blen);
+ buffer_put_string(&msg, data, datalen);
+ buffer_put_int(&msg, flags);
+ xfree(blob);
+
+ if (ssh_request_reply(auth, &msg, &msg) == 0) {
+ buffer_free(&msg);
+ return -1;
+ }
+ type = buffer_get_char(&msg);
+ if (agent_failed(type)) {
+ logit("Agent admitted failure to sign using the key.");
+ } else if (type != SSH2_AGENT_SIGN_RESPONSE) {
+ fatal("Bad authentication response: %d", type);
+ } else {
+ ret = 0;
+ *sigp = buffer_get_string(&msg, lenp);
+ }
+ buffer_free(&msg);
+ return ret;
+}
+
+/* Encode key for a message to the agent. */
+
+static void
+ssh_encode_identity_rsa1(Buffer *b, RSA *key, const char *comment)
+{
+ buffer_put_int(b, BN_num_bits(key->n));
+ buffer_put_bignum(b, key->n);
+ buffer_put_bignum(b, key->e);
+ buffer_put_bignum(b, key->d);
+ /* To keep within the protocol: p < q for ssh. in SSL p > q */
+ buffer_put_bignum(b, key->iqmp); /* ssh key->u */
+ buffer_put_bignum(b, key->q); /* ssh key->p, SSL key->q */
+ buffer_put_bignum(b, key->p); /* ssh key->q, SSL key->p */
+ buffer_put_cstring(b, comment);
+}
+
+static void
+ssh_encode_identity_ssh2(Buffer *b, Key *key, const char *comment)
+{
+ buffer_put_cstring(b, key_ssh_name(key));
+ switch (key->type) {
+ case KEY_RSA:
+ buffer_put_bignum2(b, key->rsa->n);
+ buffer_put_bignum2(b, key->rsa->e);
+ buffer_put_bignum2(b, key->rsa->d);
+ buffer_put_bignum2(b, key->rsa->iqmp);
+ buffer_put_bignum2(b, key->rsa->p);
+ buffer_put_bignum2(b, key->rsa->q);
+ break;
+ case KEY_RSA_CERT_V00:
+ case KEY_RSA_CERT:
+ if (key->cert == NULL || buffer_len(&key->cert->certblob) == 0)
+ fatal("%s: no cert/certblob", __func__);
+ buffer_put_string(b, buffer_ptr(&key->cert->certblob),
+ buffer_len(&key->cert->certblob));
+ buffer_put_bignum2(b, key->rsa->d);
+ buffer_put_bignum2(b, key->rsa->iqmp);
+ buffer_put_bignum2(b, key->rsa->p);
+ buffer_put_bignum2(b, key->rsa->q);
+ break;
+ case KEY_DSA:
+ buffer_put_bignum2(b, key->dsa->p);
+ buffer_put_bignum2(b, key->dsa->q);
+ buffer_put_bignum2(b, key->dsa->g);
+ buffer_put_bignum2(b, key->dsa->pub_key);
+ buffer_put_bignum2(b, key->dsa->priv_key);
+ break;
+ case KEY_DSA_CERT_V00:
+ case KEY_DSA_CERT:
+ if (key->cert == NULL || buffer_len(&key->cert->certblob) == 0)
+ fatal("%s: no cert/certblob", __func__);
+ buffer_put_string(b, buffer_ptr(&key->cert->certblob),
+ buffer_len(&key->cert->certblob));
+ buffer_put_bignum2(b, key->dsa->priv_key);
+ break;
+#ifdef OPENSSL_HAS_ECC
+ case KEY_ECDSA:
+ buffer_put_cstring(b, key_curve_nid_to_name(key->ecdsa_nid));
+ buffer_put_ecpoint(b, EC_KEY_get0_group(key->ecdsa),
+ EC_KEY_get0_public_key(key->ecdsa));
+ buffer_put_bignum2(b, EC_KEY_get0_private_key(key->ecdsa));
+ break;
+ case KEY_ECDSA_CERT:
+ if (key->cert == NULL || buffer_len(&key->cert->certblob) == 0)
+ fatal("%s: no cert/certblob", __func__);
+ buffer_put_string(b, buffer_ptr(&key->cert->certblob),
+ buffer_len(&key->cert->certblob));
+ buffer_put_bignum2(b, EC_KEY_get0_private_key(key->ecdsa));
+ break;
+#endif
+ }
+ buffer_put_cstring(b, comment);
+}
+
+/*
+ * Adds an identity to the authentication server. This call is not meant to
+ * be used by normal applications.
+ */
+
+int
+ssh_add_identity_constrained(AuthenticationConnection *auth, Key *key,
+ const char *comment, u_int life, u_int confirm)
+{
+ Buffer msg;
+ int type, constrained = (life || confirm);
+
+ buffer_init(&msg);
+
+ switch (key->type) {
+ case KEY_RSA1:
+ type = constrained ?
+ SSH_AGENTC_ADD_RSA_ID_CONSTRAINED :
+ SSH_AGENTC_ADD_RSA_IDENTITY;
+ buffer_put_char(&msg, type);
+ ssh_encode_identity_rsa1(&msg, key->rsa, comment);
+ break;
+ case KEY_RSA:
+ case KEY_RSA_CERT:
+ case KEY_RSA_CERT_V00:
+ case KEY_DSA:
+ case KEY_DSA_CERT:
+ case KEY_DSA_CERT_V00:
+ case KEY_ECDSA:
+ case KEY_ECDSA_CERT:
+ type = constrained ?
+ SSH2_AGENTC_ADD_ID_CONSTRAINED :
+ SSH2_AGENTC_ADD_IDENTITY;
+ buffer_put_char(&msg, type);
+ ssh_encode_identity_ssh2(&msg, key, comment);
+ break;
+ default:
+ buffer_free(&msg);
+ return 0;
+ }
+ if (constrained) {
+ if (life != 0) {
+ buffer_put_char(&msg, SSH_AGENT_CONSTRAIN_LIFETIME);
+ buffer_put_int(&msg, life);
+ }
+ if (confirm != 0)
+ buffer_put_char(&msg, SSH_AGENT_CONSTRAIN_CONFIRM);
+ }
+ if (ssh_request_reply(auth, &msg, &msg) == 0) {
+ buffer_free(&msg);
+ return 0;
+ }
+ type = buffer_get_char(&msg);
+ buffer_free(&msg);
+ return decode_reply(type);
+}
+
+/*
+ * Removes an identity from the authentication server. This call is not
+ * meant to be used by normal applications.
+ */
+
+int
+ssh_remove_identity(AuthenticationConnection *auth, Key *key)
+{
+ Buffer msg;
+ int type;
+ u_char *blob;
+ u_int blen;
+
+ buffer_init(&msg);
+
+ if (key->type == KEY_RSA1) {
+ buffer_put_char(&msg, SSH_AGENTC_REMOVE_RSA_IDENTITY);
+ buffer_put_int(&msg, BN_num_bits(key->rsa->n));
+ buffer_put_bignum(&msg, key->rsa->e);
+ buffer_put_bignum(&msg, key->rsa->n);
+ } else if (key_type_plain(key->type) == KEY_DSA ||
+ key_type_plain(key->type) == KEY_RSA ||
+ key_type_plain(key->type) == KEY_ECDSA) {
+ key_to_blob(key, &blob, &blen);
+ buffer_put_char(&msg, SSH2_AGENTC_REMOVE_IDENTITY);
+ buffer_put_string(&msg, blob, blen);
+ xfree(blob);
+ } else {
+ buffer_free(&msg);
+ return 0;
+ }
+ if (ssh_request_reply(auth, &msg, &msg) == 0) {
+ buffer_free(&msg);
+ return 0;
+ }
+ type = buffer_get_char(&msg);
+ buffer_free(&msg);
+ return decode_reply(type);
+}
+
+int
+ssh_update_card(AuthenticationConnection *auth, int add,
+ const char *reader_id, const char *pin, u_int life, u_int confirm)
+{
+ Buffer msg;
+ int type, constrained = (life || confirm);
+
+ if (add) {
+ type = constrained ?
+ SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED :
+ SSH_AGENTC_ADD_SMARTCARD_KEY;
+ } else
+ type = SSH_AGENTC_REMOVE_SMARTCARD_KEY;
+
+ buffer_init(&msg);
+ buffer_put_char(&msg, type);
+ buffer_put_cstring(&msg, reader_id);
+ buffer_put_cstring(&msg, pin);
+
+ if (constrained) {
+ if (life != 0) {
+ buffer_put_char(&msg, SSH_AGENT_CONSTRAIN_LIFETIME);
+ buffer_put_int(&msg, life);
+ }
+ if (confirm != 0)
+ buffer_put_char(&msg, SSH_AGENT_CONSTRAIN_CONFIRM);
+ }
+
+ if (ssh_request_reply(auth, &msg, &msg) == 0) {
+ buffer_free(&msg);
+ return 0;
+ }
+ type = buffer_get_char(&msg);
+ buffer_free(&msg);
+ return decode_reply(type);
+}
+
+/*
+ * Removes all identities from the agent. This call is not meant to be used
+ * by normal applications.
+ */
+
+int
+ssh_remove_all_identities(AuthenticationConnection *auth, int version)
+{
+ Buffer msg;
+ int type;
+ int code = (version==1) ?
+ SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
+ SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
+
+ buffer_init(&msg);
+ buffer_put_char(&msg, code);
+
+ if (ssh_request_reply(auth, &msg, &msg) == 0) {
+ buffer_free(&msg);
+ return 0;
+ }
+ type = buffer_get_char(&msg);
+ buffer_free(&msg);
+ return decode_reply(type);
+}
+
+int
+decode_reply(int type)
+{
+ switch (type) {
+ case SSH_AGENT_FAILURE:
+ case SSH_COM_AGENT2_FAILURE:
+ case SSH2_AGENT_FAILURE:
+ logit("SSH_AGENT_FAILURE");
+ return 0;
+ case SSH_AGENT_SUCCESS:
+ return 1;
+ default:
+ fatal("Bad response from authentication agent: %d", type);
+ }
+ /* NOTREACHED */
+ return 0;
+}