tor/changes/bug21894_029

  o Minor bugfixes (crash prevention):
    - Fix an (currently untriggerable, but potentially dangerous) crash
      bug when base32-encoding inputs whose sizes are not a multiple of
      5. Fixes bug 21894; bugfix on 0.2.9.1-alpha.
Never read off the end of a buffer in base32_encode() When we "fixed" #18280 in 4e4a7d2b0c199227252a742541461ec4cc35d358 in 0291 it appears that we introduced a bug: The base32_encode function can read off the end of the input buffer, if the input buffer size modulo 5 is not equal to 0 or 3. This is not completely horrible, for two reasons: * The extra bits that are read are never actually used: so this is only a crash when asan is enabled, in the worst case. Not a data leak. * The input sizes passed to base32_encode are only ever multiples of 5. They are all either DIGEST_LEN (20), REND_SERVICE_ID_LEN (10), sizeof(rand_bytes) in addressmap.c (10), or an input in crypto.c that is forced to a multiple of 5. So this bug can't actually trigger in today's Tor. Closes bug 21894; bugfix on 0.2.9.1-alpha. 2017-04-07 16:47:16 +02:00			`o Minor bugfixes (crash prevention):`
			`- Fix an (currently untriggerable, but potentially dangerous) crash`
			`bug when base32-encoding inputs whose sizes are not a multiple of`
			`5. Fixes bug 21894; bugfix on 0.2.9.1-alpha.`