(split_3): Take an additional parameter, S_LEN.

Adapt caller.
Map translated NEWLINE-containing filename back into the original
NEWLINE-containing name.
(md5_check): Translate NEWLINE bytes to NUL bytes in filename.

diff --git a/src/md5sum.c b/src/md5sum.c
index 2cdb459..9ebe04c 100644 (file)
--- a/src/md5sum.c
+++ b/src/md5sum.c
@@ -121,10 +121,8 @@ text), and name for each FILE.\n"),
   exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
 }
 
-/* FIXME: this format loses with filenames containing newline.  */
-
 static int
-split_3 (char *s, char **u, int *binary, char **w)
+split_3 (char *s, size_t s_len, char **u, int *binary, char **w)
 {
   size_t i;
 
@@ -136,13 +134,13 @@ split_3 (char *s, char **u, int *binary, char **w)
 
   /* The line has to be at least 35 characters long to contain correct
      message digest information.  */
-  if (strlen (&s[i]) >= 35)
+  if (s_len >= 32 + 2 + 1)
     {
       *u = &s[i];
 
       /* The first field has to be the 32-character hexadecimal
-        representation of the message digest.  If it not immediately
-        followed by a white space it's an error.  */
+        representation of the message digest.  If it is not followed
+        immediately by a white space it's an error.  */
       i += 32;
       if (!ISWHITE (s[i]))
        return 1;
@@ -151,15 +149,20 @@ split_3 (char *s, char **u, int *binary, char **w)
 
       if (s[i] != ' ' && s[i] != '*')
        return 1;
-      *binary = s[i++] == '*';
+      *binary = (s[i++] == '*');
 
       /* All characters between the type indicator and end of line are
         significant -- that includes leading and trailing white space.  */
       *w = &s[i];
 
-      /* So this line is valid as long as there is at least one character
-        for the filename.  */
-      return (**w ? 0 : 1);
+      /* Translate each NUL byte in the file name to a NEWLINE.
+         But not the last.  */
+      for (/* empty */ ; i < s_len; ++i)
+       {
+         if (s[i] == '\0')
+           s[i] = '\n';
+       }
+      return 0;
     }
   return 1;
 }
@@ -274,7 +277,9 @@ md5_check (const char *checkfile_name, int binary)
       if (line[line_length - 1] == '\n')
        line[--line_length] = '\0';
 
-      err = split_3 (line, &md5num, &type_flag, &filename);
+      /* FIXME: filename might contain NUL bytes.  Map then to NEWLINEs
+        in split_3.  */
+      err = split_3 (line, line_length, &md5num, &type_flag, &filename);
       if (err || !hex_digits (md5num))
        {
          if (warn)
@@ -507,15 +512,42 @@ main (int argc, char **argv)
        {
          size_t i;
          int fail;
+         char *file = argv[optind];
 
-         fail = md5_file (argv[optind], binary, md5buffer);
+         fail = md5_file (file, binary, md5buffer);
          err |= fail;
          if (!fail)
            {
+             size_t filename_len;
+
+             if (strchr (file, '\n'))
+               error (0, 0,
+                      _("\
+warning: filename contains a NEWLINE character `%s';  \
+you will not be able to verify this checksum using `md5sum --check'"),
+                      file);
+
              for (i = 0; i < 16; ++i)
                printf ("%02x", md5buffer[i]);
 
-             printf (" %c%s\n", binary ? '*' : ' ', argv[optind]);
+             putchar (' ');
+             if (binary)
+               putchar ('*');
+             else
+               putchar (' ');
+
+             /* Translate NEWLINE bytes to NUL bytes.
+                But first record the length of the filename, FILE.  */
+             filename_len = strlen (file);
+             for (i = 0; i < strlen (file); ++i)
+               {
+                 if (file[i] == '\n')
+                   file[i] = '\0';
+               }
+             /* Use fwrite, not printf, to output FILE --
+                now it may contain NUL bytes.  */
+             fwrite (file, sizeof (char), filename_len, stdout);
+             putchar ('\n');
            }
        }
     }