1 files changed, 104 insertions, 21 deletions

diff --git a/sshd.c b/sshd.c
index d8faaebd5..4eddeb8d8 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.397 2013/02/11 21:21:58 dtucker Exp $ */
+/* $OpenBSD: sshd.c,v 1.404 2013/07/19 07:37:48 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -106,6 +106,7 @@
 #include "canohost.h"
 #include "hostfile.h"
 #include "auth.h"
+#include "authfd.h"
 #include "misc.h"
 #include "msg.h"
 #include "dispatch.h"
@@ -198,6 +199,10 @@ char *server_version_string = NULL;
 /* for rekeying XXX fixme */
 Kex *xxx_kex;
 
+/* Daemon's agent connection */
+AuthenticationConnection *auth_conn = NULL;
+int have_agent = 0;
+
 /*
  * Any really sensitive data in the application is contained in this
  * structure. The idea is that this structure could be locked into memory so
@@ -210,6 +215,7 @@ struct {
         Key     *server_key;            /* ephemeral server key */
         Key     *ssh1_host_key;         /* ssh1 host key */
         Key     **host_keys;            /* all private host keys */
+        Key     **host_pubkeys;         /* all public host keys */
         Key     **host_certificates;    /* all public host certificates */
         int     have_ssh1_key;
         int     have_ssh2_key;
@@ -657,6 +663,8 @@ privsep_preauth(Authctxt *authctxt)
                 debug2("Network child is on pid %ld", (long)pid);
 
                 pmonitor->m_pid = pid;
+                if (have_agent)
+                        auth_conn = ssh_get_authentication_connection();
                 if (box != NULL)
                         ssh_sandbox_parent_preauth(box, pid);
                 monitor_child_preauth(authctxt, pmonitor);
@@ -771,6 +779,8 @@ list_hostkey_types(void)
         for (i = 0; i < options.num_host_key_files; i++) {
                 key = sensitive_data.host_keys[i];
                 if (key == NULL)
+                        key = sensitive_data.host_pubkeys[i];
+                if (key == NULL)
                         continue;
                 switch (key->type) {
                 case KEY_RSA:
@@ -823,6 +833,8 @@ get_hostkey_by_type(int type, int need_private)
                         break;
                 default:
                         key = sensitive_data.host_keys[i];
+                        if (key == NULL && !need_private)
+                                key = sensitive_data.host_pubkeys[i];
                         break;
                 }
                 if (key != NULL && key->type == type)
@@ -852,6 +864,14 @@ get_hostkey_by_index(int ind)
         return (sensitive_data.host_keys[ind]);
 }
 
+Key *
+get_hostkey_public_by_index(int ind)
+{
+        if (ind < 0 || ind >= options.num_host_key_files)
+                return (NULL);
+        return (sensitive_data.host_pubkeys[ind]);
+}
+
 int
 get_hostkey_index(Key *key)
 {
@@ -864,6 +884,8 @@ get_hostkey_index(Key *key)
                 } else {
                         if (key == sensitive_data.host_keys[i])
                                 return (i);
+                        if (key == sensitive_data.host_pubkeys[i])
+                                return (i);
                 }
         }
         return (-1);
@@ -904,8 +926,9 @@ usage(void)
             SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
         fprintf(stderr,
 "usage: sshd [-46DdeiqTt] [-b bits] [-C connection_spec] [-c host_cert_file]\n"
-"            [-f config_file] [-g login_grace_time] [-h host_key_file]\n"
-"            [-k key_gen_time] [-o option] [-p port] [-u len]\n"
+"            [-E log_file] [-f config_file] [-g login_grace_time]\n"
+"            [-h host_key_file] [-k key_gen_time] [-o option] [-p port]\n"
+"            [-u len]\n"
         );
         exit(1);
 }
@@ -976,7 +999,7 @@ recv_rexec_state(int fd, Buffer *conf)
         cp = buffer_get_string(&m, &len);
         if (conf != NULL)
                 buffer_append(conf, cp, len + 1);
-        xfree(cp);
+        free(cp);
 
         if (buffer_get_int(&m)) {
                 if (sensitive_data.server_key != NULL)
@@ -1027,7 +1050,9 @@ server_accept_inetd(int *sock_in, int *sock_out)
         if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
                 dup2(fd, STDIN_FILENO);
                 dup2(fd, STDOUT_FILENO);
-                if (fd > STDOUT_FILENO)
+                if (!log_stderr)
+                        dup2(fd, STDERR_FILENO);
+                if (fd > (log_stderr ? STDERR_FILENO : STDOUT_FILENO))
                         close(fd);
         }
         debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out);
@@ -1138,7 +1163,7 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
                 if (received_sighup)
                         sighup_restart();
                 if (fdset != NULL)
-                        xfree(fdset);
+                        free(fdset);
                 fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS),
                     sizeof(fd_mask));
 
@@ -1187,8 +1212,8 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
                         *newsock = accept(listen_socks[i],
                             (struct sockaddr *)&from, &fromlen);
                         if (*newsock < 0) {
-                                if (errno != EINTR && errno != EAGAIN &&
-                                    errno != EWOULDBLOCK)
+                                if (errno != EINTR && errno != EWOULDBLOCK &&
+                                    errno != ECONNABORTED && errno != EAGAIN)
                                         error("accept: %.100s",
                                             strerror(errno));
                                 if (errno == EMFILE || errno == ENFILE)
@@ -1339,12 +1364,14 @@ main(int ac, char **av)
         int sock_in = -1, sock_out = -1, newsock = -1;
         const char *remote_ip;
         int remote_port;
-        char *line;
+        char *line, *logfile = NULL;
         int config_s[2] = { -1 , -1 };
         u_int n;
         u_int64_t ibytes, obytes;
         mode_t new_umask;
         Key *key;
+        Key *pubkey;
+        int keytype;
         Authctxt *authctxt;
         struct connection_info *connection_info = get_connection_info(0, 0);
 
@@ -1377,7 +1404,7 @@ main(int ac, char **av)
         initialize_server_options(&options);
 
         /* Parse command-line arguments. */
-        while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:C:dDeiqrtQRT46")) != -1) {
+        while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:C:dDeE:iqrtQRT46")) != -1) {
                 switch (opt) {
                 case '4':
                         options.address_family = AF_INET;
@@ -1406,6 +1433,9 @@ main(int ac, char **av)
                 case 'D':
                         no_daemon_flag = 1;
                         break;
+                case 'E':
+                        logfile = xstrdup(optarg);
+                        /* FALLTHROUGH */
                 case 'e':
                         log_stderr = 1;
                         break;
@@ -1484,7 +1514,7 @@ main(int ac, char **av)
                         if (process_server_config_line(&options, line,
                             "command-line", 0, NULL, NULL) != 0)
                                 exit(1);
-                        xfree(line);
+                        free(line);
                         break;
                 case '?':
                 default:
@@ -1503,6 +1533,11 @@ main(int ac, char **av)
 
         OpenSSL_add_all_algorithms();
 
+        /* If requested, redirect the logs to the specified logfile. */
+        if (logfile != NULL) {
+                log_redirect_stderr_to(logfile);
+                free(logfile);
+        }
         /*
          * Force logging to stderr until we have loaded the private host
          * key (unless started from inetd)
@@ -1611,27 +1646,50 @@ main(int ac, char **av)
         } else {
                 memset(privsep_pw->pw_passwd, 0, strlen(privsep_pw->pw_passwd));
                 privsep_pw = pwcopy(privsep_pw);
-                xfree(privsep_pw->pw_passwd);
+                free(privsep_pw->pw_passwd);
                 privsep_pw->pw_passwd = xstrdup("*");
         }
         endpwent();
 
-        /* load private host keys */
+        /* load host keys */
         sensitive_data.host_keys = xcalloc(options.num_host_key_files,
             sizeof(Key *));
-        for (i = 0; i < options.num_host_key_files; i++)
+        sensitive_data.host_pubkeys = xcalloc(options.num_host_key_files,
+            sizeof(Key *));
+        for (i = 0; i < options.num_host_key_files; i++) {
                 sensitive_data.host_keys[i] = NULL;
+                sensitive_data.host_pubkeys[i] = NULL;
+        }
+
+        if (options.host_key_agent) {
+                if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME))
+                        setenv(SSH_AUTHSOCKET_ENV_NAME,
+                            options.host_key_agent, 1);
+                have_agent = ssh_agent_present();
+        }
 
         for (i = 0; i < options.num_host_key_files; i++) {
                 key = key_load_private(options.host_key_files[i], "", NULL);
+                pubkey = key_load_public(options.host_key_files[i], NULL);
                 sensitive_data.host_keys[i] = key;
-                if (key == NULL) {
+                sensitive_data.host_pubkeys[i] = pubkey;
+
+                if (key == NULL && pubkey != NULL && pubkey->type != KEY_RSA1 &&
+                    have_agent) {
+                        debug("will rely on agent for hostkey %s",
+                            options.host_key_files[i]);
+                        keytype = pubkey->type;
+                } else if (key != NULL) {
+                        keytype = key->type;
+                } else {
                         error("Could not load host key: %s",
                             options.host_key_files[i]);
                         sensitive_data.host_keys[i] = NULL;
+                        sensitive_data.host_pubkeys[i] = NULL;
                         continue;
                 }
-                switch (key->type) {
+
+                switch (keytype) {
                 case KEY_RSA1:
                         sensitive_data.ssh1_host_key = key;
                         sensitive_data.have_ssh1_key = 1;
@@ -1642,8 +1700,8 @@ main(int ac, char **av)
                         sensitive_data.have_ssh2_key = 1;
                         break;
                 }
-                debug("private host key: #%d type %d %s", i, key->type,
-                    key_type(key));
+                debug("private host key: #%d type %d %s", i, keytype,
+                    key_type(key ? key : pubkey));
         }
         if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
                 logit("Disabling protocol version 1. Could not load host key");
@@ -1813,7 +1871,8 @@ main(int ac, char **av)
 
         /* Chdir to the root directory so that the current disk can be
            unmounted if desired. */
-        chdir("/");
+        if (chdir("/") == -1)
+                error("chdir(\"/\"): %s", strerror(errno));
 
         /* ignore SIGPIPE */
         signal(SIGPIPE, SIG_IGN);
@@ -2069,9 +2128,11 @@ main(int ac, char **av)
         buffer_init(&loginmsg);
         auth_debug_reset();
 
-        if (use_privsep)
+        if (use_privsep) {
                 if (privsep_preauth(authctxt) == 1)
                         goto authenticated;
+        } else if (compat20 && have_agent)
+                auth_conn = ssh_get_authentication_connection();
 
         /* perform the key exchange */
         /* authenticate user and start session */
@@ -2358,7 +2419,7 @@ do_ssh1_kex(void)
                 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
                 MD5_Final(session_key + 16, &md);
                 memset(buf, 0, bytes);
-                xfree(buf);
+                free(buf);
                 for (i = 0; i < 16; i++)
                         session_id[i] = session_key[i] ^ session_key[i + 16];
         }
@@ -2385,6 +2446,23 @@ do_ssh1_kex(void)
         packet_write_wait();
 }
 
+void
+sshd_hostkey_sign(Key *privkey, Key *pubkey, u_char **signature, u_int *slen,
+    u_char *data, u_int dlen)
+{
+        if (privkey) {
+                if (PRIVSEP(key_sign(privkey, signature, slen, data, dlen) < 0))
+                        fatal("%s: key_sign failed", __func__);
+        } else if (use_privsep) {
+                if (mm_key_sign(pubkey, signature, slen, data, dlen) < 0)
+                        fatal("%s: pubkey_sign failed", __func__);
+        } else {
+                if (ssh_agent_sign(auth_conn, pubkey, signature, slen, data,
+                    dlen))
+                        fatal("%s: ssh_agent_sign failed", __func__);
+        }
+}
+
 /*
  * SSH2 key exchange: diffie-hellman-group1-sha1
  */
@@ -2416,6 +2494,10 @@ do_ssh2_kex(void)
         if (options.kex_algorithms != NULL)
                 myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
 
+        if (options.rekey_limit || options.rekey_interval)
+                packet_set_rekey_limits((u_int32_t)options.rekey_limit,
+                    (time_t)options.rekey_interval);
+
         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
 
 #ifdef GSSAPI
@@ -2480,6 +2562,7 @@ do_ssh2_kex(void)
         kex->load_host_public_key=&get_hostkey_public_by_type;
         kex->load_host_private_key=&get_hostkey_private_by_type;
         kex->host_key_index=&get_hostkey_index;
+        kex->sign = sshd_hostkey_sign;
 
         xxx_kex = kex;