diff -uprk.orig openssh-3.6.1p1.orig/ssh-agent.1 openssh-3.6.1p1/ssh-agent.1

--- openssh-3.6.1p1.orig/ssh-agent.1	2003-04-01 15:42:14 +0400

+++ openssh-3.6.1p1/ssh-agent.1	2003-04-11 19:09:40 +0400

@@ -45,6 +45,7 @@

 .Op Fl a Ar bind_address

 .Op Fl c Li | Fl s

 .Op Fl t Ar life

+.Op Fl u

 .Op Fl d

 .Op Ar command Op Ar args ...

 .Nm ssh-agent

@@ -95,6 +96,8 @@ A lifetime specified for an identity wit

 .Xr ssh-add 1

 overrides this value.

 Without this option the default maximum lifetime is forever.

+.It Fl u

+Run the agent in unique mode.

 .It Fl d

 Debug mode.

 When this option is specified

@@ -174,6 +177,7 @@ Contains the protocol version 2 DSA auth

 .It Pa $HOME/.ssh/id_rsa

 Contains the protocol version 2 RSA authentication identity of the user.

 .It Pa /tmp/ssh-XXXXXXXX/agent.<ppid>

+.It Pa ~/.ssh/agent

 Unix-domain sockets used to contain the connection to the

 authentication agent.

 These sockets should only be readable by the owner.

diff -uprk.orig openssh-3.6.1p1.orig/ssh-agent.c openssh-3.6.1p1/ssh-agent.c

--- openssh-3.6.1p1.orig/ssh-agent.c	2003-04-11 18:58:18 +0400

+++ openssh-3.6.1p1/ssh-agent.c	2003-04-11 19:19:53 +0400

@@ -971,6 +971,30 @@ check_parent_exists(int sig)

 	errno = save_errno;

 }

+static int

+check_auth_socket(const char *authsocket)

+{

+	int sock, len, ret;

+	struct sockaddr_un sunaddr;

+

+	sunaddr.sun_family = AF_UNIX;

+	strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));

+#ifdef HAVE_SUN_LEN_IN_SOCKADDR_UN

+	sunaddr.sun_len = len = SUN_LEN(&sunaddr)+1;

+#else /* HAVE_SUN_LEN_IN_SOCKADDR_UN */

+	len = SUN_LEN(&sunaddr)+1;

+#endif /* HAVE_SUN_LEN_IN_SOCKADDR_UN */

+

+	sock = socket(AF_UNIX, SOCK_STREAM, 0);

+	if (sock < 0)

+		return -1;

+

+	ret = connect(sock, (struct sockaddr *) & sunaddr, len);

+	close(sock);

+

+	return ret;

+}

+

 static void

 usage(void)

 {

@@ -980,6 +1004,7 @@ usage(void)

 	fprintf(stderr, "  -c          Generate C-shell commands on stdout.\n");

 	fprintf(stderr, "  -s          Generate Bourne shell commands on stdout.\n");

 	fprintf(stderr, "  -k          Kill the current agent.\n");

+	fprintf(stderr, "  -u          Unique mode.\n");

 	fprintf(stderr, "  -d          Debug mode.\n");

 	fprintf(stderr, "  -a socket   Bind agent socket to given name.\n");

 	fprintf(stderr, "  -t life     Default identity lifetime (seconds).\n");

@@ -989,7 +1014,7 @@ usage(void)

 int

 main(int ac, char **av)

 {

-	int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;

+	int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0, u_flag = 0, already_running = 0;

 	int sock, fd,  ch, nalloc;

 	char *shell, *format, *pidstr, *agentsocket = NULL;

 	fd_set *readsetp = NULL, *writesetp = NULL;

@@ -997,13 +1022,10 @@ main(int ac, char **av)

 #ifdef HAVE_SETRLIMIT

 	struct rlimit rlim;

 #endif

-#ifdef HAVE_CYGWIN

 	int prev_mask;

-#endif

 	extern int optind;

 	extern char *optarg;

 	pid_t pid;

-	char pidstrbuf[1 + 3 * sizeof pid];

 	/* drop */

 	setegid(getgid());

@@ -1027,7 +1049,7 @@ main(int ac, char **av)

 	init_rng();

 	seed_rng();

-	while ((ch = getopt(ac, av, "cdksa:t:")) != -1) {

+	while ((ch = getopt(ac, av, "cdksua:t:")) != -1) {

 		switch (ch) {

 		case 'c':

 			if (s_flag)

@@ -1042,6 +1064,9 @@ main(int ac, char **av)

 				usage();

 			s_flag++;

 			break;

+		case 'u':

+			u_flag++;

+			break;

 		case 'd':

 			if (d_flag)

 				usage();

@@ -1063,7 +1088,10 @@ main(int ac, char **av)

 	ac -= optind;

 	av += optind;

-	if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))

+	if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || u_flag))

+		usage();

+

+	if (u_flag && (k_flag || agentsocket))

 		usage();

 	if (ac == 0 && !c_flag && !s_flag) {

@@ -1074,19 +1102,16 @@ main(int ac, char **av)

 	if (k_flag) {

 		pidstr = getenv(SSH_AGENTPID_ENV_NAME);

 		if (pidstr == NULL) {

-			fprintf(stderr, "%s not set, cannot kill agent\n",

-			    SSH_AGENTPID_ENV_NAME);

-			exit(1);

+			fatal("%s: %s not set, cannot kill agent",

+			    __progname, SSH_AGENTPID_ENV_NAME);

 		}

 		pid = atoi(pidstr);

 		if (pid < 1) {

-			fprintf(stderr, "%s=\"%s\", which is not a good PID\n",

-			    SSH_AGENTPID_ENV_NAME, pidstr);

-			exit(1);

+			fatal("%s: %s=\"%s\", which is not a good PID",

+			    __progname, SSH_AGENTPID_ENV_NAME, pidstr);

 		}

 		if (kill(pid, SIGTERM) == -1) {

-			perror("kill");

-			exit(1);

+			fatal("%s: kill: %s", __progname, strerror(errno));

 		}

 		format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";

 		printf(format, SSH_AUTHSOCKET_ENV_NAME);

@@ -1096,12 +1121,17 @@ main(int ac, char **av)

 	}

 	parent_pid = getpid();

-	if (agentsocket == NULL) {

+	if (u_flag) {

+		struct passwd *pw = getpwuid(geteuid());

+		if (!pw)

+			fatal("%s: getpwuid: %s", __progname, strerror(errno));

+		snprintf(socket_name, sizeof socket_name, "%s/.ssh/agent", pw->pw_dir);

+	}

+	else if (agentsocket == NULL) {

 		/* Create private directory for agent socket */

 		strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir);

 		if (mkdtemp(socket_dir) == NULL) {

-			perror("mkdtemp: private socket dir");

-			exit(1);

+			fatal("%s: mkdtemp: private socket dir: %s", __progname, strerror(errno));

 		}

 		snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,

 		    (long)parent_pid);

@@ -1117,27 +1147,51 @@ main(int ac, char **av)

 	 */

 	sock = socket(AF_UNIX, SOCK_STREAM, 0);

 	if (sock < 0) {

-		perror("socket");

+		error("%s: socket: %s", __progname, strerror(errno));

 		cleanup_exit(1);

 	}

 	memset(&sunaddr, 0, sizeof(sunaddr));

 	sunaddr.sun_family = AF_UNIX;

 	strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));

-#ifdef HAVE_CYGWIN

 	prev_mask = umask(0177);

-#endif

 	if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) {

-		perror("bind");

-#ifdef HAVE_CYGWIN

-		umask(prev_mask);

-#endif

-		cleanup_exit(1);

+		if (u_flag && (EADDRINUSE == errno)) {

+			if (check_auth_socket(socket_name) >= 0)

+				already_running = 1;

+			else {

+				unlink(socket_name);

+				if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) {

+					error("%s: bind: %s: %s", __progname, socket_name, strerror(errno));

+					cleanup_exit(1);

+				}

+			}

+		}

+		else {

+			error("%s: bind: %s: %s", __progname, socket_name, strerror(errno));

+			cleanup_exit(1);

+		}

 	}

-#ifdef HAVE_CYGWIN

 	umask(prev_mask);

-#endif

+

+	if (already_running) {

+		close(sock);

+		if (ac == 0) {

+			format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";

+			printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,

+			    SSH_AUTHSOCKET_ENV_NAME);

+			exit(0);

+		}

+		if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) < 0) {

+			error("%s: setenv: %s", __progname, strerror(errno));

+			exit(1);

+		}

+		execvp(av[0], av);

+		perror(av[0]);

+		exit(1);

+	}

+

 	if (listen(sock, 128) < 0) {

-		perror("listen");

+		error("%s: listen: %s", __progname, strerror(errno));

 		cleanup_exit(1);

 	}

@@ -1155,10 +1209,11 @@ main(int ac, char **av)

 	}

 	pid = fork();

 	if (pid == -1) {

-		perror("fork");

+		error("%s: fork: %s", __progname, strerror(errno));

 		cleanup_exit(1);

 	}

 	if (pid != 0) {		/* Parent - execute the given command. */

+		char pidstrbuf[1 + 3 * sizeof pid];

 		close(sock);

 		snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);

 		if (ac == 0) {

@@ -1172,8 +1227,7 @@ main(int ac, char **av)

 		}

 		if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||

 		    setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {

-			perror("setenv");

-			exit(1);

+			fatal("%s: setenv: %s", __progname, strerror(errno));

 		}

 		log_done();

 		execvp(av[0], av);

@@ -1210,7 +1264,7 @@ main(int ac, char **av)

 skip:

 	fatal_add_cleanup(cleanup_socket, NULL);

 	new_socket(AUTH_SOCKET, sock);

-	if (ac > 0) {

+	if (!u_flag && ac > 0) {

 		signal(SIGALRM, check_parent_exists);

 		alarm(10);

 	}