diff --git a/agent/sexp-parse.h b/agent/sexp-parse.h new file mode 100644 index 000000000..6baca08cf --- /dev/null +++ b/agent/sexp-parse.h @@ -0,0 +1,98 @@ +/* sexp-parse.h - S-Exp helper functions + * Copyright (C) 2002 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * GnuPG is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#ifndef SEXP_PARSE_H +#define SEXP_PARSE_H + +#include "../common/util.h" + +/* Return the length of the next S-Exp part and update the pointer to + the first data byte. 0 is return on error */ +static inline size_t +snext (unsigned char const **buf) +{ + const unsigned char *s; + int n; + + s = *buf; + for (n=0; *s && *s != ':' && digitp (s); s++) + n = n*10 + atoi_1 (s); + if (!n || *s != ':') + return 0; /* we don't allow empty lengths */ + *buf = s+1; + return n; +} + +/* Skip over the S-Expression BUF points to and update BUF to point to + the chacter right behind. DEPTH gives the initial number of open + lists and may be passed as a positive number to skip over the + remainder of an S-Expression if the current position is somewhere + in an S-Expression. The function may return an error code if it + encounters an impossible conditions */ +static inline int +sskip (unsigned char const **buf, int *depth) +{ + const unsigned char *s = *buf; + size_t n; + int d = *depth; + + while (d > 0) + { + if (*s == '(') + { + d++; + s++; + } + else if (*s == ')') + { + d--; + s++; + } + else + { + if (!d) + return GNUPG_Invalid_Sexp; + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + s += n; + } + } + *buf = s; + *depth = d; + return 0; +} + + +/* Check whether the the string at the address BUF points to matches + the token. Return true on match and update BUF to point behind the + token. */ +static inline int +smatch (unsigned char const **buf, size_t buflen, const char *token) +{ + size_t toklen = strlen (token); + + if (buflen != toklen || memcmp (*buf, token, toklen)) + return 0; + *buf += toklen; + return 1; +} + +#endif /*SEXP_PARSE_H*/