Gilles Peskine 42a1acfd0e get_len_step: Fix end-of-buffer calculation when buffer_size==0
Fix get_len_step when buffer_size==0. The intent of this test is to
ensure (via static or runtime buffer overflow analysis) that
mbedtls_asn1_get_len does not attempt to access beyond the end of the
buffer. When buffer_size is 0 (reached from get_len when parsing a
1-byte buffer), the buffer is buf[1..1] because allocating a 0-byte
buffer might yield a null pointer rather than a valid pointer. In this
case the end of the buffer is p==buf+1, not buf+buffer_size which is
buf+0.

The test passed because calling mbedtls_asn1_get_len(&p,end,...) with
end < p happens to work, but this is not guaranteed.
2020-01-21 16:12:07 +01:00
..
2015-04-08 13:25:31 +02:00