upstream: when scp is in SFTP mode, try to deal better with ~

prefixed paths. ~user paths aren't supported, but ~/ paths will be accepted
and prefixed with the SFTP server starting directory (more to come)

prompted by and discussed with deraadt@
ok markus@

OpenBSD-Commit-ID: 263a071f14555c045fd03132a8fb6cbd983df00d

diff --git a/scp.c b/scp.c
index 21467c465888de714aed188abe3c5a9f30509310..fe3ac70118e30eeeb80a97a442e992f200e37da8 100644 (file)
--- a/scp.c
+++ b/scp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: scp.c,v 1.225 2021/08/09 07:21:01 djm Exp $ */
+/* $OpenBSD: scp.c,v 1.226 2021/08/09 23:44:32 djm Exp $ */
 /*
  * scp - secure remote copy.  This is basically patched BSD rcp which
  * uses ssh to do the data transfer (instead of using rcmd).
@@ -1253,6 +1253,29 @@ tolocal(int argc, char **argv, enum scp_mode_e mode, char *sftp_direct)
        free(src);
 }
 
+/* Canonicalise a remote path, handling ~ by assuming cwd is the homedir */
+static char *
+absolute_remote_path(const char *path, const char *remote_path)
+{
+       char *ret;
+
+       /* Handle ~ prefixed paths */
+       if (*path != '~')
+               ret = xstrdup(path);
+       else {
+               if (strcmp(path, "~") == 0)
+                       ret = xstrdup("");
+               else if (strncmp(path, "~/", 2) == 0)
+                       ret = xstrdup(path + 2);
+               else {
+                       /* XXX could be supported with protocol extension */
+                       error("~user paths are not currently supported");
+                       return NULL;
+               }
+       }
+       return make_absolute(ret, remote_path);
+}
+
 void
 source_sftp(int argc, char *src, char *targ,
     struct sftp_conn *conn, char **remote_path)
@@ -1273,8 +1296,8 @@ source_sftp(int argc, char *src, char *targ,
         * No need to glob here - the local shell already took care of
         * the expansions
         */
-       target = xstrdup(targ);
-       target = make_absolute(target, *remote_path);
+       if ((target = absolute_remote_path(targ, *remote_path)) == NULL)
+               cleanup_exit(255);
        target_is_dir = remote_is_dir(conn, target);
        if (targetshouldbedirectory && !target_is_dir) {
                fatal("Target is not a directory, but more files selected "
@@ -1471,6 +1494,7 @@ sink_sftp(int argc, char *dst, const char *src, struct sftp_conn *conn)
        char *filename, *tmp = NULL, *remote_path = NULL;
        int i, r, err = 0;
 
+       memset(&g, 0, sizeof(g));
        /*
         * Here, we need remote glob as SFTP can not depend on remote shell
         * expansions
@@ -1484,10 +1508,11 @@ sink_sftp(int argc, char *dst, const char *src, struct sftp_conn *conn)
                goto out;
        }
 
-       abs_src = xstrdup(src);
-       abs_src = make_absolute(abs_src, remote_path);
+       if ((abs_src = absolute_remote_path(src, remote_path)) == NULL) {
+               err = -1;
+               goto out;
+       }
        free(remote_path);
-       memset(&g, 0, sizeof(g));
 
        debug3_f("copying remote %s to local %s", abs_src, dst);
        if ((r = remote_glob(conn, abs_src, GLOB_MARK, NULL, &g)) != 0) {
@@ -1895,11 +1920,10 @@ throughlocal_sftp(struct sftp_conn *from, struct sftp_conn *to,
        if ((filename = basename(src)) == NULL)
                fatal("basename %s: %s", src, strerror(errno));
 
-       abs_src = xstrdup(src);
-       abs_src = make_absolute(abs_src, from_remote_path);
+       if ((abs_src = absolute_remote_path(src, from_remote_path)) == NULL ||
+           (target = absolute_remote_path(targ, *to_remote_path)) == NULL)
+               cleanup_exit(255);
        free(from_remote_path);
-       target = xstrdup(targ);
-       target = make_absolute(target, *to_remote_path);
        memset(&g, 0, sizeof(g));
 
        targetisdir = remote_is_dir(to, target);