We found this in #40076, after we started using buf_move_all() in
more places. Fixes bug #40076; bugfix on 0.3.3.1-alpha. As far as
I know, the crash only affects master, but I think this warrants a
backport, "just in case".
This patch changes our bits-to-bytes conversion logic in the NSS
implementation of `tor_tls_cert_matches_key()` from using (x >> 3) to
((x + 7) >> 3) since DER bit-strings are allowed to contain a number of
bits that is not a multiple of 8.
Additionally, we add a comment on why we cannot use the
`DER_ConvertBitString()` macro from NSS, as we would potentially apply
the bits-to-bytes conversion logic twice, which would lead to an
insignificant amount of bytes being compared in
`SECITEM_ItemsAreEqual()` and thus turn the logic into being a
prefix match instead of a full match.
The `DER_ConvertBitString()` macro is defined in NSS as:
/*
** Macro to convert der decoded bit string into a decoded octet
** string. All it needs to do is fiddle with the length code.
*/
#define DER_ConvertBitString(item) \
{ \
(item)->len = ((item)->len + 7) >> 3; \
}
Thanks to Taylor Yu for spotting this problem.
This patch is part of the fix for TROVE-2020-001.
See: https://bugs.torproject.org/33119
We add constness to `peer_info_orig_len` and `cert_info_orig_len` in
`tor_tls_cert_matches_key` to ensure that we don't accidentally alter
the variables.
This patch is part of the fix for TROVE-2020-001.
See: https://bugs.torproject.org/33119
This patch fixes an out-of-bound memory read in
`tor_tls_cert_matches_key()` when Tor is compiled to use Mozilla's NSS
instead of OpenSSL.
The NSS library stores some length fields in bits instead of bytes, but
the comparison function found in `SECITEM_ItemsAreEqual()` needs the
length to be encoded in bytes. This means that for a 140-byte,
DER-encoded, SubjectPublicKeyInfo struct (with a 1024-bit RSA public key
in it), we would ask `SECITEM_ItemsAreEqual()` to compare the first 1120
bytes instead of 140 (140bytes * 8bits = 1120bits).
This patch fixes the issue by converting from bits to bytes before
calling `SECITEM_ItemsAreEqual()` and convert the `len`-fields back to
bits before we leave the function.
This patch is part of the fix for TROVE-2020-001.
See: https://bugs.torproject.org/33119
This patch lifts the `tor_tls_cert_matches_key()` tests out of the
OpenSSL specific TLS test suite and moves it into the generic TLS test
suite that is executed for both OpenSSL and NSS.
This patch is largely a code movement, but we had to rewrite parts of
the test to avoid using OpenSSL specific data-types (such as `X509 *`)
and replace it with the generic Tor abstraction type
(`tor_x509_cert_impl_t *`).
This patch is part of the fix for TROVE-2020-001.
See: https://bugs.torproject.org/33119
This is not actually a bug! It can happen for a bunch of reasons,
which all boil down to "trying to add an extrainfo for which we no
longer have the corresponding routerinfo".
Fixes#16016; bugfix on 0.2.6.3-alpha.
