upstream: factor out reading/writing sshbufs to dedicated

functions; feedback and ok markus@

OpenBSD-Commit-ID: dc09e5f1950b7acc91b8fdf8015347782d2ecd3d

1 files changed, 118 insertions, 0 deletions

diff --git a/sshbuf-io.c b/sshbuf-io.c
new file mode 100644
index 000000000..65f745858
--- /dev/null
+++ b/sshbuf-io.c
@@ -0,0 +1,118 @@
+/*      $OpenBSD: sshbuf-io.c,v 1.1 2020/01/25 23:02:14 djm Exp $ */
+/*
+ * Copyright (c) 2011 Damien Miller
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "ssherr.h"
+#define SSHBUF_INTERNAL
+#include "sshbuf.h"
+#include "atomicio.h"
+
+/* Load a file from a fd into a buffer */
+int
+sshbuf_load_fd(int fd, struct sshbuf **blobp)
+{
+        u_char buf[4096];
+        size_t len;
+        struct stat st;
+        int r;
+        struct sshbuf *blob;
+
+        *blobp = NULL;
+
+        if (fstat(fd, &st) == -1)
+                return SSH_ERR_SYSTEM_ERROR;
+        if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
+            st.st_size > SSHBUF_SIZE_MAX)
+                return SSH_ERR_INVALID_FORMAT;
+        if ((blob = sshbuf_new()) == NULL)
+                return SSH_ERR_ALLOC_FAIL;
+        for (;;) {
+                if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {
+                        if (errno == EPIPE)
+                                break;
+                        r = SSH_ERR_SYSTEM_ERROR;
+                        goto out;
+                }
+                if ((r = sshbuf_put(blob, buf, len)) != 0)
+                        goto out;
+                if (sshbuf_len(blob) > SSHBUF_SIZE_MAX) {
+                        r = SSH_ERR_INVALID_FORMAT;
+                        goto out;
+                }
+        }
+        if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
+            st.st_size != (off_t)sshbuf_len(blob)) {
+                r = SSH_ERR_FILE_CHANGED;
+                goto out;
+        }
+        /* success */
+        *blobp = blob;
+        blob = NULL; /* transferred */
+        r = 0;
+ out:
+        explicit_bzero(buf, sizeof(buf));
+        sshbuf_free(blob);
+        return r;
+}
+
+int
+sshbuf_load_file(const char *path, struct sshbuf **bufp)
+{
+        int r, fd, oerrno;
+
+        *bufp = NULL;
+        if ((fd = open(path, O_RDONLY)) == -1)
+                return SSH_ERR_SYSTEM_ERROR;
+        if ((r = sshbuf_load_fd(fd, bufp)) != 0)
+                goto out;
+        /* success */
+        r = 0;
+ out:
+        oerrno = errno;
+        close(fd);
+        if (r != 0)
+                errno = oerrno;
+        return r;
+}
+
+int
+sshbuf_write_file(const char *path, struct sshbuf *buf)
+{
+        int fd, oerrno;
+
+        if ((fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644)) == -1)
+                return SSH_ERR_SYSTEM_ERROR;
+        if (atomicio(vwrite, fd, sshbuf_mutable_ptr(buf),
+            sshbuf_len(buf)) != sshbuf_len(buf) || close(fd) != 0) {
+                oerrno = errno;
+                close(fd);
+                unlink(path);
+                errno = oerrno;
+                return SSH_ERR_SYSTEM_ERROR;
+        }
+        return 0;
+}
+