Avoid negative indices, especially with unsigned types

This commit is contained in:
Frank Denis 2019-01-03 22:28:42 +01:00
parent 1cd6641cde
commit 32385c6b9a

View File

@ -742,7 +742,7 @@ sodium_pad(size_t *padded_buflen_p, unsigned char *buf,
for (i = 0; i < blocksize; i++) {
barrier_mask = (unsigned char) (((i ^ xpadlen) - 1U)
>> ((sizeof(size_t) - 1) * CHAR_BIT));
tail[-i] = (tail[-i] & mask) | (0x80 & barrier_mask);
*(tail - i) = ((*(tail - i)) & mask) | (0x80 & barrier_mask);
mask |= barrier_mask;
}
return 0;
@ -766,7 +766,7 @@ sodium_unpad(size_t *unpadded_buflen_p, const unsigned char *buf,
tail = &buf[padded_buflen - 1U];
for (i = 0U; i < blocksize; i++) {
c = tail[-i];
c = *(tail - i);
is_barrier =
(( (acc - 1U) & (pad_len - 1U) & ((c ^ 0x80) - 1U) ) >> 8) & 1U;
acc |= c;