When encoding a legacy ESTABLISH_INTRO cell, we were using the sizeof() on a
pointer instead of using the real size of the destination buffer leading to an
overflow passing an enormous value to the signing digest function.
Fortunately, that value was only used to make sure the destination buffer
length was big enough for the key size and in this case it always was because
of the overflow.
Fixes#21553
Signed-off-by: David Goulet <dgoulet@torproject.org>
This patch adds checks for expected log messages for failure cases of
different ill-formed ESTABLISH_INTRO cell's.
See: https://bugs.torproject.org/21266
This commit adds 3 unit tests which validates a wrong signature length, a
wrong authentication key length and a wrong MAC in the cell.
Closes#20992
Signed-off-by: David Goulet <dgoulet@torproject.org>
