The relay authentication used non-constant-time comparisons (strcasecmp,
strcmp) to verify password hashes and plaintext passwords, allowing an
attacker to derive the expected hash byte-by-byte from response timing
and then authenticate without knowing the password.
- SHA/PBKDF2 hex hash comparisons: normalize the client-supplied hash to
uppercase and compare in constant time over the fixed expected length.
- Plaintext password comparison: HMAC-SHA256 both passwords with a fresh
per-call random key and compare the fixed-size MACs in constant time,
hiding both per-byte timing and the password length.
Add string_memcmp_constant_time helper in core, exposed via the plugin
API. Bump WEECHAT_PLUGIN_API_VERSION accordingly.
Now the function utf8_next_char with an empty string returns NULL instead of
the next char, which is most of the time after an allocated buffer.
And the function utf8_char_size with an empty string now returns 0 instead of
1.
This indirectly fixes a buffer overflow in function eval_string_range_chars
when the input string is empty (for example when doing `/eval -n ${chars:}`).
At the moment, building WeeChat triggers several thousand -Wstrict-prototypes
diagnostics. This is due to its source code using an empty argument list for
functions and function pointers that take no arguments, instead of explicitly
declaring that they take no arguments by using a void list.
This commit replaces all empty argument lists with a void list.
Note that Ruby's headers also suffer the same problem, which WeeChat can't
do anything to fix. Thus, building WeeChat with the Ruby plugin enabled
will still issue approximately 30 such diagnostics.
This fixes a bug when writing configuration files with a wrong locale: now
UTF-8 is kept and written in files instead of string converted using a wrong
charset.
Sébastien Helleu