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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 09:59:15 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 09:59:15 +0000 |
commit | 8de1ee1b2b676b0d07586f0752750dd6b0fb7511 (patch) | |
tree | dd46fd7dc3863045696cd0e48032d8a36fa0daf5 /common/sexp-parse.h | |
parent | Initial commit. (diff) | |
download | gnupg2-upstream.tar.xz gnupg2-upstream.zip |
Adding upstream version 2.2.27.upstream/2.2.27upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'common/sexp-parse.h')
-rw-r--r-- | common/sexp-parse.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/common/sexp-parse.h b/common/sexp-parse.h new file mode 100644 index 0000000..4f77f14 --- /dev/null +++ b/common/sexp-parse.h @@ -0,0 +1,137 @@ +/* sexp-parse.h - S-expression helper functions + * Copyright (C) 2002, 2003, 2007 Free Software Foundation, Inc. + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of either + * + * - the GNU Lesser General Public License as published by the Free + * Software Foundation; either version 3 of the License, or (at + * your option) any later version. + * + * or + * + * - 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. + * + * or both in parallel, as here. + * + * This file 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, see <https://www.gnu.org/licenses/>. + */ + +#ifndef SEXP_PARSE_H +#define SEXP_PARSE_H + +#include <gpg-error.h> + + +/* Return the length of the next S-Exp part and update the pointer to + the first data byte. 0 is returned on error */ +static inline size_t +snext (unsigned char const **buf) +{ + const unsigned char *s; + int n; + + s = *buf; + for (n=0; *s && *s != ':' && (*s >= '0' && *s <= '9'); s++) + n = n*10 + (*s - '0'); + 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 character 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 condition. */ +static inline gpg_error_t +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 gpg_error (GPG_ERR_INV_SEXP); + n = snext (&s); + if (!n) + return gpg_error (GPG_ERR_INV_SEXP); + s += n; + } + } + *buf = s; + *depth = d; + return 0; +} + + +/* Check whether the string at the address BUF points to matches + the token. Return true on match and update BUF to point behind the + token. Return false and do not update the buffer if it does not + match. */ +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; +} + +/* Format VALUE for use as the length indicatior of an S-expression. + The caller needs to provide a buffer HELP_BUFFER wth a length of + HELP_BUFLEN. The return value is a pointer into HELP_BUFFER with + the formatted length string. The colon and a trailing nul are + appended. HELP_BUFLEN must be at least 3 - a more useful value is + 15. If LENGTH is not NULL, the LENGTH of the resulting string + (excluding the terminating nul) is stored at that address. */ +static inline char * +smklen (char *help_buffer, size_t help_buflen, size_t value, size_t *length) +{ + char *p = help_buffer + help_buflen; + + if (help_buflen >= 3) + { + *--p = 0; + *--p = ':'; + do + { + *--p = '0' + (value % 10); + value /= 10; + } + while (value && p > help_buffer); + } + + if (length) + *length = (help_buffer + help_buflen) - p; + return p; +} + + +#endif /*SEXP_PARSE_H*/ |