]> andersk Git - openssh.git/blobdiff - sshconnect.c
- deraadt@cvs.openbsd.org 2006/03/20 18:42:27
[openssh.git] / sshconnect.c
index 95bb527b2a123d3f4b051e1a87666135aed5481f..33961e4dc169e264846726e03c15bfc19af8c25e 100644 (file)
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect.c,v 1.157 2004/05/08 00:21:31 djm Exp $");
 
-#include <openssl/bn.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+
+#include <ctype.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
 
 #include "ssh.h"
 #include "xmalloc.h"
@@ -31,13 +37,12 @@ RCSID("$OpenBSD: sshconnect.c,v 1.157 2004/05/08 00:21:31 djm Exp $");
 #include "readconf.h"
 #include "atomicio.h"
 #include "misc.h"
-
 #include "dns.h"
 
 char *client_version_string = NULL;
 char *server_version_string = NULL;
 
-int matching_host_key_dns = 0;
+static int matching_host_key_dns = 0;
 
 /* import */
 extern Options options;
@@ -59,12 +64,11 @@ static void warn_changed_key(Key *);
 static int
 ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
 {
-       Buffer command;
-       const char *cp;
-       char *command_string;
+       char *command_string, *tmp;
        int pin[2], pout[2];
        pid_t pid;
        char strport[NI_MAXSERV];
+       size_t len;
 
        /* Convert the port number into a string. */
        snprintf(strport, sizeof strport, "%hu", port);
@@ -76,31 +80,13 @@ ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
         * Use "exec" to avoid "sh -c" processes on some platforms
         * (e.g. Solaris)
         */
-       buffer_init(&command);
-       buffer_append(&command, "exec ", 5);
-
-       for (cp = proxy_command; *cp; cp++) {
-               if (cp[0] == '%' && cp[1] == '%') {
-                       buffer_append(&command, "%", 1);
-                       cp++;
-                       continue;
-               }
-               if (cp[0] == '%' && cp[1] == 'h') {
-                       buffer_append(&command, host, strlen(host));
-                       cp++;
-                       continue;
-               }
-               if (cp[0] == '%' && cp[1] == 'p') {
-                       buffer_append(&command, strport, strlen(strport));
-                       cp++;
-                       continue;
-               }
-               buffer_append(&command, cp, 1);
-       }
-       buffer_append(&command, "\0", 1);
-
-       /* Get the final command string. */
-       command_string = buffer_ptr(&command);
+       len = strlen(proxy_command) + 6;
+       tmp = xmalloc(len);
+       strlcpy(tmp, "exec ", len);
+       strlcat(tmp, proxy_command, len);
+       command_string = percent_expand(tmp, "h", host,
+           "p", strport, (char *)NULL);
+       xfree(tmp);
 
        /* Create pipes for communicating with the proxy. */
        if (pipe(pin) < 0 || pipe(pout) < 0)
@@ -154,7 +140,7 @@ ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
        close(pout[1]);
 
        /* Free the command name. */
-       buffer_free(&command);
+       xfree(command_string);
 
        /* Set the connection file descriptors. */
        packet_set_connection(pout[0], pin[1]);
@@ -247,13 +233,13 @@ timeout_connect(int sockfd, const struct sockaddr *serv_addr,
        tv.tv_sec = timeout;
        tv.tv_usec = 0;
 
-       for(;;) {
+       for (;;) {
                rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
                if (rc != -1 || errno != EINTR)
                        break;
        }
 
-       switch(rc) {
+       switch (rc) {
        case 0:
                /* Timed out */
                errno = ETIMEDOUT;
@@ -297,12 +283,6 @@ timeout_connect(int sockfd, const struct sockaddr *serv_addr,
  * second).  If proxy_command is non-NULL, it specifies the command (with %h
  * and %p substituted for host and port, respectively) to use to contact
  * the daemon.
- * Return values:
- *    0 for OK
- *    ECONNREFUSED if we got a "Connection Refused" by the peer on any address
- *    ECONNABORTED if we failed without a "Connection refused"
- * Suitable error messages for the connection failure will already have been
- * printed.
  */
 int
 ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
@@ -314,24 +294,9 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
        int sock = -1, attempt;
        char ntop[NI_MAXHOST], strport[NI_MAXSERV];
        struct addrinfo hints, *ai, *aitop;
-       struct servent *sp;
-       /*
-        * Did we get only other errors than "Connection refused" (which
-        * should block fallback to rsh and similar), or did we get at least
-        * one "Connection refused"?
-        */
-       int full_failure = 1;
 
        debug2("ssh_connect: needpriv %d", needpriv);
 
-       /* Get default port if port has not been set. */
-       if (port == 0) {
-               sp = getservbyname(SSH_SERVICE_NAME, "tcp");
-               if (sp)
-                       port = ntohs(sp->s_port);
-               else
-                       port = SSH_DEFAULT_PORT;
-       }
        /* If a proxy command is given, connect using it. */
        if (proxy_command != NULL)
                return ssh_proxy_connect(host, port, proxy_command);
@@ -381,8 +346,6 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
                                memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
                                break;
                        } else {
-                               if (errno == ECONNREFUSED)
-                                       full_failure = 0;
                                debug("connect to address %s port %s: %s",
                                    ntop, strport, strerror(errno));
                                /*
@@ -408,9 +371,9 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
 
        /* Return failure if we didn't get a successful connection. */
        if (attempt >= connection_attempts) {
-               logit("ssh: connect to host %s port %s: %s",
+               error("ssh: connect to host %s port %s: %s",
                    host, strport, strerror(errno));
-               return full_failure ? ECONNABORTED : ECONNREFUSED;
+               return (-1);
        }
 
        debug("Connection established.");
@@ -435,19 +398,21 @@ static void
 ssh_exchange_identification(void)
 {
        char buf[256], remote_version[256];     /* must be same size! */
-       int remote_major, remote_minor, i, mismatch;
+       int remote_major, remote_minor, mismatch;
        int connection_in = packet_get_connection_in();
        int connection_out = packet_get_connection_out();
        int minor1 = PROTOCOL_MINOR_1;
+       u_int i;
 
-       /* Read other side\'s version identification. */
+       /* Read other side's version identification. */
        for (;;) {
                for (i = 0; i < sizeof(buf) - 1; i++) {
-                       int len = atomicio(read, connection_in, &buf[i], 1);
-                       if (len < 0)
-                               fatal("ssh_exchange_identification: read: %.100s", strerror(errno));
-                       if (len != 1)
+                       size_t len = atomicio(read, connection_in, &buf[i], 1);
+
+                       if (len != 1 && errno == EPIPE)
                                fatal("ssh_exchange_identification: Connection closed by remote host");
+                       else if (len != 1)
+                               fatal("ssh_exchange_identification: read: %.100s", strerror(errno));
                        if (buf[i] == '\r') {
                                buf[i] = '\n';
                                buf[i + 1] = 0;
@@ -568,7 +533,7 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
        char hostline[1000], *hostp, *fp;
        HostStatus host_status;
        HostStatus ip_status;
-       int local = 0, host_ip_differ = 0;
+       int r, local = 0, host_ip_differ = 0;
        int salen;
        char ntop[NI_MAXHOST];
        char msg[1024];
@@ -587,7 +552,7 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
        switch (hostaddr->sa_family) {
        case AF_INET:
                local = (ntohl(((struct sockaddr_in *)hostaddr)->
-                  sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
+                   sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
                salen = sizeof(struct sockaddr_in);
                break;
        case AF_INET6:
@@ -644,7 +609,7 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
        file_key = key_new(host_key->type);
 
        /*
-        * Check if the host key is present in the user\'s list of known
+        * Check if the host key is present in the user's list of known
         * hosts or in the systemwide list.
         */
        host_file = user_hostfile;
@@ -692,7 +657,7 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
                                    "'%.128s' not in list of known hosts.",
                                    type, ip);
                        else if (!add_host_to_hostfile(user_hostfile, ip,
-                           host_key))
+                           host_key, options.hash_known_hosts))
                                logit("Failed to add the %s host key for IP "
                                    "address '%.128s' to the list of known "
                                    "hosts (%.30s).", type, ip, user_hostfile);
@@ -720,8 +685,8 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
 
                        if (show_other_keys(host, host_key))
                                snprintf(msg1, sizeof(msg1),
-                                  "\nbut keys of different type are already"
-                                  " known for this host.");
+                                   "\nbut keys of different type are already"
+                                   " known for this host.");
                        else
                                snprintf(msg1, sizeof(msg1), ".");
                        /* The default */
@@ -748,17 +713,33 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
                        if (!confirm(msg))
                                goto fail;
                }
-               if (options.check_host_ip && ip_status == HOST_NEW) {
-                       snprintf(hostline, sizeof(hostline), "%s,%s", host, ip);
-                       hostp = hostline;
-               } else
-                       hostp = host;
-
                /*
                 * If not in strict mode, add the key automatically to the
                 * local known_hosts file.
                 */
-               if (!add_host_to_hostfile(user_hostfile, hostp, host_key))
+               if (options.check_host_ip && ip_status == HOST_NEW) {
+                       snprintf(hostline, sizeof(hostline), "%s,%s",
+                           host, ip);
+                       hostp = hostline;
+                       if (options.hash_known_hosts) {
+                               /* Add hash of host and IP separately */
+                               r = add_host_to_hostfile(user_hostfile, host,
+                                   host_key, options.hash_known_hosts) &&
+                                   add_host_to_hostfile(user_hostfile, ip,
+                                   host_key, options.hash_known_hosts);
+                       } else {
+                               /* Add unhashed "host,ip" */
+                               r = add_host_to_hostfile(user_hostfile,
+                                   hostline, host_key,
+                                   options.hash_known_hosts);
+                       }
+               } else {
+                       r = add_host_to_hostfile(user_hostfile, host, host_key,
+                           options.hash_known_hosts);
+                       hostp = host;
+               }
+
+               if (!r)
                        logit("Failed to add the host to the list of known "
                            "hosts (%.500s).", user_hostfile);
                else
@@ -767,19 +748,19 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
                break;
        case HOST_CHANGED:
                if (options.check_host_ip && host_ip_differ) {
-                       char *msg;
+                       char *key_msg;
                        if (ip_status == HOST_NEW)
-                               msg = "is unknown";
+                               key_msg = "is unknown";
                        else if (ip_status == HOST_OK)
-                               msg = "is unchanged";
+                               key_msg = "is unchanged";
                        else
-                               msg = "has a different value";
+                               key_msg = "has a different value";
                        error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
                        error("@       WARNING: POSSIBLE DNS SPOOFING DETECTED!          @");
                        error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
                        error("The %s host key for %s has changed,", type, host);
                        error("and the key for the according IP address %s", ip);
-                       error("%s. This could either mean that", msg);
+                       error("%s. This could either mean that", key_msg);
                        error("DNS SPOOFING is happening or the IP address for the host");
                        error("and its host key have changed at the same time.");
                        if (ip_status != HOST_NEW)
@@ -946,7 +927,7 @@ ssh_login(Sensitive *sensitive, const char *orighost,
        host = xstrdup(orighost);
        for (cp = host; *cp; cp++)
                if (isupper(*cp))
-                       *cp = tolower(*cp);
+                       *cp = (char)tolower(*cp);
 
        /* Exchange protocol version identification strings with the server. */
        ssh_exchange_identification();
@@ -1059,3 +1040,39 @@ warn_changed_key(Key *host_key)
 
        xfree(fp);
 }
+
+/*
+ * Execute a local command
+ */
+int
+ssh_local_cmd(const char *args)
+{
+       char *shell;
+       pid_t pid;
+       int status;
+
+       if (!options.permit_local_command ||
+           args == NULL || !*args)
+               return (1);
+
+       if ((shell = getenv("SHELL")) == NULL)
+               shell = _PATH_BSHELL;
+
+       pid = fork();
+       if (pid == 0) {
+               debug3("Executing %s -c \"%s\"", shell, args);
+               execl(shell, shell, "-c", args, (char *)NULL);
+               error("Couldn't execute %s -c \"%s\": %s",
+                   shell, args, strerror(errno));
+               _exit(1);
+       } else if (pid == -1)
+               fatal("fork failed: %.100s", strerror(errno));
+       while (waitpid(pid, &status, 0) == -1)
+               if (errno != EINTR)
+                       fatal("Couldn't wait for child: %s", strerror(errno));
+
+       if (!WIFEXITED(status))
+               return (1);
+
+       return (WEXITSTATUS(status));
+}
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