1 files changed, 158 insertions, 39 deletions

diff --git a/sshconnect.c b/sshconnect.c
index 3280b310d..15d8b807e 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.287 2017/09/14 04:32:21 djm Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.297 2018/02/23 15:58:38 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -23,6 +23,7 @@
 # include <sys/time.h>
 #endif
 
+#include <net/if.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
@@ -43,6 +44,9 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#ifdef HAVE_IFADDRS_H
+# include <ifaddrs.h>
+#endif
 
 #include "xmalloc.h"
 #include "key.h"
@@ -270,14 +274,83 @@ ssh_kill_proxy_command(void)
                 kill(proxy_command_pid, SIGHUP);
 }
 
+#ifdef HAVE_IFADDRS_H
+/*
+ * Search a interface address list (returned from getifaddrs(3)) for an
+ * address that matches the desired address family on the specifed interface.
+ * Returns 0 and fills in *resultp and *rlenp on success. Returns -1 on failure.
+ */
+static int
+check_ifaddrs(const char *ifname, int af, const struct ifaddrs *ifaddrs,
+    struct sockaddr_storage *resultp, socklen_t *rlenp)
+{
+        struct sockaddr_in6 *sa6;
+        struct sockaddr_in *sa;
+        struct in6_addr *v6addr;
+        const struct ifaddrs *ifa;
+        int allow_local;
+
+        /*
+         * Prefer addresses that are not loopback or linklocal, but use them
+         * if nothing else matches.
+         */
+        for (allow_local = 0; allow_local < 2; allow_local++) {
+                for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
+                        if (ifa->ifa_addr == NULL || ifa->ifa_name == NULL ||
+                            (ifa->ifa_flags & IFF_UP) == 0 ||
+                            ifa->ifa_addr->sa_family != af ||
+                            strcmp(ifa->ifa_name, options.bind_interface) != 0)
+                                continue;
+                        switch (ifa->ifa_addr->sa_family) {
+                        case AF_INET:
+                                sa = (struct sockaddr_in *)ifa->ifa_addr;
+                                if (!allow_local && sa->sin_addr.s_addr ==
+                                    htonl(INADDR_LOOPBACK))
+                                        continue;
+                                if (*rlenp < sizeof(struct sockaddr_in)) {
+                                        error("%s: v4 addr doesn't fit",
+                                            __func__);
+                                        return -1;
+                                }
+                                *rlenp = sizeof(struct sockaddr_in);
+                                memcpy(resultp, sa, *rlenp);
+                                return 0;
+                        case AF_INET6:
+                                sa6 = (struct sockaddr_in6 *)ifa->ifa_addr;
+                                v6addr = &sa6->sin6_addr;
+                                if (!allow_local &&
+                                    (IN6_IS_ADDR_LINKLOCAL(v6addr) ||
+                                    IN6_IS_ADDR_LOOPBACK(v6addr)))
+                                        continue;
+                                if (*rlenp < sizeof(struct sockaddr_in6)) {
+                                        error("%s: v6 addr doesn't fit",
+                                            __func__);
+                                        return -1;
+                                }
+                                *rlenp = sizeof(struct sockaddr_in6);
+                                memcpy(resultp, sa6, *rlenp);
+                                return 0;
+                        }
+                }
+        }
+        return -1;
+}
+#endif
+
 /*
  * Creates a (possibly privileged) socket for use as the ssh connection.
  */
 static int
 ssh_create_socket(int privileged, struct addrinfo *ai)
 {
-        int sock, r, gaierr;
+        int sock, r, oerrno;
+        struct sockaddr_storage bindaddr;
+        socklen_t bindaddrlen = 0;
         struct addrinfo hints, *res = NULL;
+#ifdef HAVE_IFADDRS_H
+        struct ifaddrs *ifaddrs = NULL;
+#endif
+        char ntop[NI_MAXHOST];
 
         sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
         if (sock < 0) {
@@ -287,22 +360,55 @@ ssh_create_socket(int privileged, struct addrinfo *ai)
         fcntl(sock, F_SETFD, FD_CLOEXEC);
 
         /* Bind the socket to an alternative local IP address */
-        if (options.bind_address == NULL && !privileged)
+        if (options.bind_address == NULL && options.bind_interface == NULL &&
+            !privileged)
                 return sock;
 
-        if (options.bind_address) {
+        if (options.bind_address != NULL) {
                 memset(&hints, 0, sizeof(hints));
                 hints.ai_family = ai->ai_family;
                 hints.ai_socktype = ai->ai_socktype;
                 hints.ai_protocol = ai->ai_protocol;
                 hints.ai_flags = AI_PASSIVE;
-                gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res);
-                if (gaierr) {
+                if ((r = getaddrinfo(options.bind_address, NULL,
+                    &hints, &res)) != 0) {
                         error("getaddrinfo: %s: %s", options.bind_address,
-                            ssh_gai_strerror(gaierr));
-                        close(sock);
-                        return -1;
+                            ssh_gai_strerror(r));
+                        goto fail;
+                }
+                if (res == NULL) {
+                        error("getaddrinfo: no addrs");
+                        goto fail;
                 }
+                if (res->ai_addrlen > sizeof(bindaddr)) {
+                        error("%s: addr doesn't fit", __func__);
+                        goto fail;
+                }
+                memcpy(&bindaddr, res->ai_addr, res->ai_addrlen);
+                bindaddrlen = res->ai_addrlen;
+        } else if (options.bind_interface != NULL) {
+#ifdef HAVE_IFADDRS_H
+                if ((r = getifaddrs(&ifaddrs)) != 0) {
+                        error("getifaddrs: %s: %s", options.bind_interface,
+                              strerror(errno));
+                        goto fail;
+                }
+                bindaddrlen = sizeof(bindaddr);
+                if (check_ifaddrs(options.bind_interface, ai->ai_family,
+                    ifaddrs, &bindaddr, &bindaddrlen) != 0) {
+                        logit("getifaddrs: %s: no suitable addresses",
+                              options.bind_interface);
+                        goto fail;
+                }
+#else
+                error("BindInterface not supported on this platform.");
+#endif
+        }
+        if ((r = getnameinfo((struct sockaddr *)&bindaddr, bindaddrlen,
+            ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST)) != 0) {
+                error("%s: getnameinfo failed: %s", __func__,
+                    ssh_gai_strerror(r));
+                goto fail;
         }
         /*
          * If we are running as root and want to connect to a privileged
@@ -310,25 +416,32 @@ ssh_create_socket(int privileged, struct addrinfo *ai)
          */
         if (privileged) {
                 PRIV_START;
-                r = bindresvport_sa(sock, res ? res->ai_addr : NULL);
+                r = bindresvport_sa(sock,
+                        bindaddrlen == 0 ? NULL : (struct sockaddr *)&bindaddr);
+                oerrno = errno;
                 PRIV_END;
                 if (r < 0) {
-                        error("bindresvport_sa: af=%d %s", ai->ai_family,
-                            strerror(errno));
+                        error("bindresvport_sa %s: %s", ntop,
+                            strerror(oerrno));
                         goto fail;
                 }
-        } else {
-                if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
-                        error("bind: %s: %s", options.bind_address,
-                            strerror(errno));
- fail:
-                        close(sock);
-                        freeaddrinfo(res);
-                        return -1;
-                }
+        } else if (bind(sock, (struct sockaddr *)&bindaddr, bindaddrlen) != 0) {
+                error("bind %s: %s", ntop, strerror(errno));
+                goto fail;
         }
+        debug("%s: bound to %s", __func__, ntop);
+        /* success */
+        goto out;
+fail:
+        close(sock);
+        sock = -1;
+ out:
         if (res != NULL)
                 freeaddrinfo(res);
+#ifdef HAVE_IFADDRS_H
+        if (ifaddrs != NULL)
+                freeifaddrs(ifaddrs);
+#endif
         return sock;
 }
 
@@ -344,7 +457,7 @@ waitrfd(int fd, int *timeoutp)
         struct timeval t_start;
         int oerrno, r;
 
-        gettimeofday(&t_start, NULL);
+        monotime_tv(&t_start);
         pfd.fd = fd;
         pfd.events = POLLIN;
         for (; *timeoutp >= 0;) {
@@ -416,7 +529,7 @@ ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop,
     int connection_attempts, int *timeout_ms, int want_keepalive, int needpriv)
 {
         int on = 1;
-        int sock = -1, attempt;
+        int oerrno, sock = -1, attempt;
         char ntop[NI_MAXHOST], strport[NI_MAXSERV];
         struct addrinfo *ai;
 
@@ -436,12 +549,16 @@ ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop,
                  */
                 for (ai = aitop; ai; ai = ai->ai_next) {
                         if (ai->ai_family != AF_INET &&
-                            ai->ai_family != AF_INET6)
+                            ai->ai_family != AF_INET6) {
+                                errno = EAFNOSUPPORT;
                                 continue;
+                        }
                         if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
                             ntop, sizeof(ntop), strport, sizeof(strport),
                             NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
+                                oerrno = errno;
                                 error("%s: getnameinfo failed", __func__);
+                                errno = oerrno;
                                 continue;
                         }
                         debug("Connecting to %.200s [%.100s] port %s.",
@@ -449,9 +566,11 @@ ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop,
 
                         /* Create a socket for connecting. */
                         sock = ssh_create_socket(needpriv, ai);
-                        if (sock < 0)
+                        if (sock < 0) {
                                 /* Any error is already output */
+                                errno = 0;
                                 continue;
+                        }
 
                         if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
                             timeout_ms) >= 0) {
@@ -459,10 +578,12 @@ ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop,
                                 memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
                                 break;
                         } else {
+                                oerrno = errno;
                                 debug("connect to address %s port %s: %s",
                                     ntop, strport, strerror(errno));
                                 close(sock);
                                 sock = -1;
+                                errno = oerrno;
                         }
                 }
                 if (sock != -1)
@@ -472,8 +593,8 @@ ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop,
         /* Return failure if we didn't get a successful connection. */
         if (sock == -1) {
                 error("ssh: connect to host %s port %s: %s",
-                    host, strport, strerror(errno));
-                return (-1);
+                    host, strport, errno == 0 ? "failure" : strerror(errno));
+                return -1;
         }
 
         debug("Connection established.");
@@ -610,9 +731,6 @@ ssh_exchange_identification(int timeout_ms)
         if (mismatch)
                 fatal("Protocol major versions differ: %d vs. %d",
                     PROTOCOL_MAJOR_2, remote_major);
-        if ((datafellows & SSH_BUG_DERIVEKEY) != 0)
-                fatal("Server version \"%.100s\" uses unsafe key agreement; "
-                    "refusing connection", remote_version);
         if ((datafellows & SSH_BUG_RSASIGMD5) != 0)
                 logit("Server version \"%.100s\" uses unsafe RSA signature "
                     "scheme; disabling use of RSA keys", remote_version);
@@ -631,11 +749,12 @@ confirm(const char *prompt)
                 return 0;
         for (msg = prompt;;msg = again) {
                 p = read_passphrase(msg, RP_ECHO);
-                if (p == NULL ||
-                    (p[0] == '\0') || (p[0] == '\n') ||
-                    strncasecmp(p, "no", 2) == 0)
+                if (p == NULL)
+                        return 0;
+                p[strcspn(p, "\n")] = '\0';
+                if (p[0] == '\0' || strcasecmp(p, "no") == 0)
                         ret = 0;
-                if (p && strncasecmp(p, "yes", 3) == 0)
+                else if (strcasecmp(p, "yes") == 0)
                         ret = 1;
                 free(p);
                 if (ret != -1)
@@ -1178,8 +1297,7 @@ fail:
                 host_key = raw_key;
                 goto retry;
         }
-        if (raw_key != NULL)
-                sshkey_free(raw_key);
+        sshkey_free(raw_key);
         free(ip);
         free(host);
         if (host_hostkeys != NULL)
@@ -1364,6 +1482,7 @@ show_other_keys(struct hostkeys *hostkeys, struct sshkey *key)
                 KEY_DSA,
                 KEY_ECDSA,
                 KEY_ED25519,
+                KEY_XMSS,
                 -1
         };
         int i, ret = 0;
@@ -1460,8 +1579,8 @@ ssh_local_cmd(const char *args)
 }
 
 void
-maybe_add_key_to_agent(char *authfile, struct sshkey *private, char *comment,
-    char *passphrase)
+maybe_add_key_to_agent(char *authfile, const struct sshkey *private,
+    char *comment, char *passphrase)
 {
         int auth_sock = -1, r;
 
@@ -1481,7 +1600,7 @@ maybe_add_key_to_agent(char *authfile, struct sshkey *private, char *comment,
         }
 
         if ((r = ssh_add_identity_constrained(auth_sock, private, comment, 0,
-            (options.add_keys_to_agent == 3))) == 0)
+            (options.add_keys_to_agent == 3), 0)) == 0)
                 debug("identity added to agent: %s", authfile);
         else
                 debug("could not add identity to agent: %s (%d)", authfile, r);