parser: security: UTF-8 and NUL handling in literals.

A null byte in regex and string literals is being processed as
a #\nul instead of correctly turning into #\pnul. Bad UTF-8 is
not being rejected.

* parser.l (REGCHAR, LITCHAR): Use utf8_from_buffer to
properly convert yytext using its true length, rather than
utf8_from which assumes a null-terminated string. Thus
null bytes (including the case of a yytext being single NUL)
are handled properly. Check that the result is exactly one
character (null-terminated buffer, two characters wide).

* utf8.c (utf8_from): Unused function removed.

* utf8.h (utf8_from): Declaration removed.

1 files changed, 0 insertions, 6 deletions

diff --git a/utf8.c b/utf8.c
index 620c6bdb..c5f9f3dc 100644
--- a/utf8.c
+++ b/utf8.c
@@ -139,12 +139,6 @@ size_t utf8_from_buf(wchar_t *wdst, const unsigned char *src, size_t nbytes)
   return nchar;
 }
 
-size_t utf8_from(wchar_t *wdst, const char *src)
-{
-  size_t nbytes = strlen(src);
-  return utf8_from_buf(wdst, coerce(const unsigned char *, src), nbytes);
-}
-
 size_t utf8_to_buf(unsigned char *dst, const wchar_t *wsrc, int null_term)
 {
   size_t nbyte = 0;