Remove base64_decode_nopad() because it is redundant now that
base64_decode() correctly handles both padded and unpadded base64
encodings with "right-sized" output buffers.
base64_decode() was applying an overly conservative check on the
output buffer length that could incorrectly produce an error if the
input encoding contained padding or newlines. Fix this by checking
the output buffer length against the actual decoded length produced
during decoding.
When we "fixed" #18280 in 4e4a7d2b0c
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.
It looks like 32_encoded_size/64_encode_size APIs are inconsistent
not only in the number of "d"s they have, but also in whether they
count the terminating NUL. Taylor noted this in 86477f4e3f,
but I think we should note the inconsistently more loudly in order
to avoid trouble.
(I ran into trouble with this when writing 30b13fd82e243713c6a0d.)
Make sure to memset(0) the destination buffer so we don't leave any
uninitialized data.
Fixes#19462
Signed-off-by: David Goulet <dgoulet@torproject.org>
base16_decodes() now returns the number of decoded bytes. It's interface
changes from returning a "int" to a "ssize_t". Every callsite now checks the
returned value.
Fixes#14013
Signed-off-by: David Goulet <dgoulet@torproject.org>
The base64 and base32 functions used to be in crypto.c;
crypto_format.h had no header; some general-purpose functions were in
crypto_curve25519.c.
This patch makes a {crypto,util}_format.[ch], and puts more functions
there. Small modules are beautiful!
