]> andersk Git - openssh.git/blobdiff - sshd.c
- (djm) OpenBSD CVS Updates:
[openssh.git] / sshd.c
diff --git a/sshd.c b/sshd.c
index a13332cbddce8d01007ec384a696a1e1ba6678c5..cab0dd6f1b4b6b8c4949ef504023bcd6f18ea207 100644 (file)
--- a/sshd.c
+++ b/sshd.c
@@ -14,7 +14,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.116 2000/05/17 08:20:16 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.122 2000/07/11 08:11:34 deraadt Exp $");
 
 #include "xmalloc.h"
 #include "rsa.h"
@@ -88,6 +88,7 @@ char *av0;
 
 /* Saved arguments to main(). */
 char **saved_argv;
+int saved_argc;
 
 /*
  * The sockets that the server is listening; this is used in the SIGHUP
@@ -296,7 +297,7 @@ sshd_exchange_identification(int sock_in, int sock_out)
 
                /* Read other side\'s version identification. */
                for (i = 0; i < sizeof(buf) - 1; i++) {
-                       if (read(sock_in, &buf[i], 1) != 1) {
+                       if (atomicio(read, sock_in, &buf[i], 1) != 1) {
                                log("Did not receive ident string from %s.", get_remote_ipaddr());
                                fatal_cleanup();
                        }
@@ -349,7 +350,7 @@ sshd_exchange_identification(int sock_in, int sock_out)
                        break;
                }
                if (remote_minor < 3) {
-                       packet_disconnect("Your ssh version is too old and"
+                       packet_disconnect("Your ssh version is too old and "
                            "is no longer supported.  Please install a newer version.");
                } else if (remote_minor == 3) {
                        /* note that this disables agent-forwarding */
@@ -389,13 +390,19 @@ void
 destroy_sensitive_data(void)
 {
        /* Destroy the private and public keys.  They will no longer be needed. */
-       RSA_free(public_key);
-       RSA_free(sensitive_data.private_key);
-       RSA_free(sensitive_data.host_key);
+       if (public_key)
+               RSA_free(public_key);
+       if (sensitive_data.private_key)
+               RSA_free(sensitive_data.private_key);
+       if (sensitive_data.host_key)
+               RSA_free(sensitive_data.host_key);
        if (sensitive_data.dsa_host_key != NULL)
                key_free(sensitive_data.dsa_host_key);
 }
 
+int *startup_pipes = NULL;     /* options.max_startup sized array of fd ints */
+int startup_pipe;              /* in child */
+
 /*
  * Main program for the daemon.
  */
@@ -404,7 +411,7 @@ main(int ac, char **av)
 {
        extern char *optarg;
        extern int optind;
-       int opt, sock_in = 0, sock_out = 0, newsock, i, fdsetsz, on = 1;
+       int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
        pid_t pid;
        socklen_t fromlen;
        int silent = 0;
@@ -417,8 +424,13 @@ main(int ac, char **av)
        struct addrinfo *ai;
        char ntop[NI_MAXHOST], strport[NI_MAXSERV];
        int listen_sock, maxfd;
+       int startup_p[2];
+       int startups = 0;
+
+       init_rng();
 
        /* Save argv[0]. */
+       saved_argc = ac;
        saved_argv = av;
        if (strchr(av[0], '/'))
                av0 = strrchr(av[0], '/') + 1;
@@ -739,6 +751,7 @@ main(int ac, char **av)
 
                /* Arrange to restart on SIGHUP.  The handler needs listen_sock. */
                signal(SIGHUP, sighup_handler);
+
                signal(SIGTERM, sigterm_handler);
                signal(SIGQUIT, sigterm_handler);
 
@@ -746,12 +759,15 @@ main(int ac, char **av)
                signal(SIGCHLD, main_sigchld_handler);
 
                /* setup fd set for listen */
+               fdset = NULL;
                maxfd = 0;
                for (i = 0; i < num_listen_socks; i++)
                        if (listen_socks[i] > maxfd)
                                maxfd = listen_socks[i];
-               fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
-               fdset = (fd_set *)xmalloc(fdsetsz);
+               /* pipes connected to unauthenticated childs */
+               startup_pipes = xmalloc(options.max_startups * sizeof(int));
+               for (i = 0; i < options.max_startups; i++)
+                       startup_pipes[i] = -1;
 
                /*
                 * Stay listening for connections until the system crashes or
@@ -760,80 +776,129 @@ main(int ac, char **av)
                for (;;) {
                        if (received_sighup)
                                sighup_restart();
-                       /* Wait in select until there is a connection. */
+                       if (fdset != NULL)
+                               xfree(fdset);
+                       fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
+                       fdset = (fd_set *)xmalloc(fdsetsz);
                        memset(fdset, 0, fdsetsz);
+
                        for (i = 0; i < num_listen_socks; i++)
                                FD_SET(listen_socks[i], fdset);
+                       for (i = 0; i < options.max_startups; i++)
+                               if (startup_pipes[i] != -1)
+                                       FD_SET(startup_pipes[i], fdset);
+
+                       /* Wait in select until there is a connection. */
                        if (select(maxfd + 1, fdset, NULL, NULL, NULL) < 0) {
                                if (errno != EINTR)
                                        error("select: %.100s", strerror(errno));
                                continue;
                        }
+                       for (i = 0; i < options.max_startups; i++)
+                               if (startup_pipes[i] != -1 &&
+                                   FD_ISSET(startup_pipes[i], fdset)) {
+                                       /*
+                                        * the read end of the pipe is ready
+                                        * if the child has closed the pipe
+                                        * after successfull authentication
+                                        * or if the child has died
+                                        */
+                                       close(startup_pipes[i]);
+                                       startup_pipes[i] = -1;
+                                       startups--;
+                               }
                        for (i = 0; i < num_listen_socks; i++) {
                                if (!FD_ISSET(listen_socks[i], fdset))
                                        continue;
-                       fromlen = sizeof(from);
-                       newsock = accept(listen_socks[i], (struct sockaddr *)&from,
-                           &fromlen);
-                       if (newsock < 0) {
-                               if (errno != EINTR && errno != EWOULDBLOCK)
-                                       error("accept: %.100s", strerror(errno));
-                               continue;
-                       }
-                       if (fcntl(newsock, F_SETFL, 0) < 0) {
-                               error("newsock del O_NONBLOCK: %s", strerror(errno));
-                               continue;
-                       }
-                       /*
-                        * Got connection.  Fork a child to handle it, unless
-                        * we are in debugging mode.
-                        */
-                       if (debug_flag) {
-                               /*
-                                * In debugging mode.  Close the listening
-                                * socket, and start processing the
-                                * connection without forking.
-                                */
-                               debug("Server will not fork when running in debugging mode.");
-                               close_listen_socks();
-                               sock_in = newsock;
-                               sock_out = newsock;
-                               pid = getpid();
-                               break;
-                       } else {
+                               fromlen = sizeof(from);
+                               newsock = accept(listen_socks[i], (struct sockaddr *)&from,
+                                   &fromlen);
+                               if (newsock < 0) {
+                                       if (errno != EINTR && errno != EWOULDBLOCK)
+                                               error("accept: %.100s", strerror(errno));
+                                       continue;
+                               }
+                               if (fcntl(newsock, F_SETFL, 0) < 0) {
+                                       error("newsock del O_NONBLOCK: %s", strerror(errno));
+                                       continue;
+                               }
+                               if (startups >= options.max_startups) {
+                                       close(newsock);
+                                       continue;
+                               }
+                               if (pipe(startup_p) == -1) {
+                                       close(newsock);
+                                       continue;
+                               }
+
+                               for (j = 0; j < options.max_startups; j++)
+                                       if (startup_pipes[j] == -1) {
+                                               startup_pipes[j] = startup_p[0];
+                                               if (maxfd < startup_p[0])
+                                                       maxfd = startup_p[0];
+                                               startups++;
+                                               break;
+                                       }
+                               
                                /*
-                                * Normal production daemon.  Fork, and have
-                                * the child process the connection. The
-                                * parent continues listening.
+                                * Got connection.  Fork a child to handle it, unless
+                                * we are in debugging mode.
                                 */
-                               if ((pid = fork()) == 0) {
+                               if (debug_flag) {
                                        /*
-                                        * Child.  Close the listening socket, and start using the
-                                        * accepted socket.  Reinitialize logging (since our pid has
-                                        * changed).  We break out of the loop to handle the connection.
+                                        * In debugging mode.  Close the listening
+                                        * socket, and start processing the
+                                        * connection without forking.
                                         */
+                                       debug("Server will not fork when running in debugging mode.");
                                        close_listen_socks();
                                        sock_in = newsock;
                                        sock_out = newsock;
-                                       log_init(av0, options.log_level, options.log_facility, log_stderr);
+                                       startup_pipe = -1;
+                                       pid = getpid();
                                        break;
+                               } else {
+                                       /*
+                                        * Normal production daemon.  Fork, and have
+                                        * the child process the connection. The
+                                        * parent continues listening.
+                                        */
+                                       if ((pid = fork()) == 0) {
+                                               /*
+                                                * Child.  Close the listening and max_startup
+                                                * sockets.  Start using the accepted socket.
+                                                * Reinitialize logging (since our pid has
+                                                * changed).  We break out of the loop to handle
+                                                * the connection.
+                                                */
+                                               startup_pipe = startup_p[1];
+                                               for (j = 0; j < options.max_startups; j++)
+                                                       if (startup_pipes[j] != -1)
+                                                               close(startup_pipes[j]);
+                                               close_listen_socks();
+                                               sock_in = newsock;
+                                               sock_out = newsock;
+                                               log_init(av0, options.log_level, options.log_facility, log_stderr);
+                                               break;
+                                       }
                                }
-                       }
 
-                       /* Parent.  Stay in the loop. */
-                       if (pid < 0)
-                               error("fork: %.100s", strerror(errno));
-                       else
-                               debug("Forked child %d.", pid);
+                               /* Parent.  Stay in the loop. */
+                               if (pid < 0)
+                                       error("fork: %.100s", strerror(errno));
+                               else
+                                       debug("Forked child %d.", pid);
 
-                       /* Mark that the key has been used (it was "given" to the child). */
-                       key_used = 1;
+                               close(startup_p[1]);
 
-                       arc4random_stir();
+                               /* Mark that the key has been used (it was "given" to the child). */
+                               key_used = 1;
+
+                               arc4random_stir();
 
-                       /* Close the new socket (the child is now taking care of it). */
-                       close(newsock);
-                       } /* for (i = 0; i < num_listen_socks; i++) */
+                               /* Close the new socket (the child is now taking care of it). */
+                               close(newsock);
+                       }
                        /* child process check (or debug mode) */
                        if (num_listen_socks < 0)
                                break;
@@ -1156,7 +1221,6 @@ do_ssh2_kex()
        int payload_len, dlen;
        int slen;
        unsigned int klen, kout;
-       char *ptr;
        unsigned char *signature = NULL;
        unsigned char *server_host_key_blob = NULL;
        unsigned int sbloblen;
@@ -1168,7 +1232,6 @@ do_ssh2_kex()
        unsigned char *hash;
        Kex *kex;
        char *cprop[PROPOSAL_MAX];
-       char *sprop[PROPOSAL_MAX];
 
 /* KEXINIT */
 
@@ -1176,46 +1239,15 @@ do_ssh2_kex()
                myproposal[PROPOSAL_ENC_ALGS_CTOS] =
                myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
        }
-
-       debug("Sending KEX init.");
-
-       for (i = 0; i < PROPOSAL_MAX; i++)
-               sprop[i] = xstrdup(myproposal[i]);
-       server_kexinit = kex_init(sprop);
-       packet_start(SSH2_MSG_KEXINIT);
-       packet_put_raw(buffer_ptr(server_kexinit), buffer_len(server_kexinit)); 
-       packet_send();
-       packet_write_wait();
-
-       debug("done");
-
-       packet_read_expect(&payload_len, SSH2_MSG_KEXINIT);
-
-       /*
-        * save raw KEXINIT payload in buffer. this is used during
-        * computation of the session_id and the session keys.
-        */
+       server_kexinit = kex_init(myproposal);
        client_kexinit = xmalloc(sizeof(*client_kexinit));
        buffer_init(client_kexinit);
-       ptr = packet_get_raw(&payload_len);
-       buffer_append(client_kexinit, ptr, payload_len);
-
-       /* skip cookie */
-       for (i = 0; i < 16; i++)
-               (void) packet_get_char();
-       /* save kex init proposal strings */
-       for (i = 0; i < PROPOSAL_MAX; i++) {
-               cprop[i] = packet_get_string(NULL);
-               debug("got kexinit string: %s", cprop[i]);
-       }
-
-       i = (int) packet_get_char();
-       debug("first kex follow == %d", i);
-       i = packet_get_int();
-       debug("reserved == %d", i);
 
-       debug("done read kexinit");
-       kex = kex_choose_conf(cprop, sprop, 1);
+       /* algorithm negotiation */
+       kex_exchange_kexinit(server_kexinit, client_kexinit, cprop);
+       kex = kex_choose_conf(cprop, myproposal, 1);
+       for (i = 0; i < PROPOSAL_MAX; i++)
+               xfree(cprop[i]);
 
 /* KEXDH */
 
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