From 04e846f33403058cd4b0e5c951c5a08e836782fd Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Wed, 14 Feb 2018 23:45:20 -0800 Subject: [PROPOSED 2/2] Allow specialized usage without TZDIR Suggested by Manuela Friedrich for MS-Windows in: https://mm.icann.org/pipermail/tz/2018-February/026228.html * localtime.c (tzloadbody) [SUPPRESS_TZDIR]: Do not prepend TZDIR/ to relative names if TZDIR is empty. --- Makefile | 2 ++ NEWS | 5 +++++ localtime.c | 6 ++++++ 3 files changed, 13 insertions(+) diff --git a/Makefile b/Makefile index ad3b123..47acbbd 100644 --- a/Makefile +++ b/Makefile @@ -208,6 +208,8 @@ LDLIBS= # -DRESERVE_STD_EXT_IDS if your platform reserves standard identifiers # with external linkage, e.g., applications cannot define 'localtime'. # -Dssize_t=long on hosts like MS-Windows that lack ssize_t +# -DSUPPRESS_TZDIR to not prepend TZDIR to file names; this has +# security implemencations and is not recommended for general use # -DTHREAD_SAFE to make localtime.c thread-safe, as POSIX requires; # not needed by the main-program tz code, which is single-threaded. # Append other compiler flags as needed, e.g., -pthread on GNU/Linux. diff --git a/NEWS b/NEWS index 09ee326..999522b 100644 --- a/NEWS +++ b/NEWS @@ -50,6 +50,11 @@ Unreleased, experimental changes already can use vanguard.zi; in this respect, current tzcode is bleeding-edge. + When built with -DSUPPRESS_TZDIR, the tzcode library no longer + prepends TZDIR/ to file names that do not begin with '/'. This is + not recommended for general use, due to its security implications. + (From a suggestion by Manuela Friedrich.) + Changes to code zic now accepts subsecond precision in expressions like diff --git a/localtime.c b/localtime.c index 6f5aa76..b6b82bb 100644 --- a/localtime.c +++ b/localtime.c @@ -400,7 +400,13 @@ tzloadbody(char const *name, struct state *sp, bool doextend, if (name[0] == ':') ++name; +#ifdef SUPPRESS_TZDIR + /* Do not prepend TZDIR. This is intended for specialized + applications only, due to its security implications. */ + doaccess = true; +#else doaccess = name[0] == '/'; +#endif if (!doaccess) { size_t namelen = strlen(name); if (sizeof lsp->fullname - sizeof tzdirslash <= namelen) -- 2.7.4