Alexander Færøy 7b2d10700f Use ((x + 7) >> 3) instead of (x >> 3) when converting from bits to bytes.
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
2020-07-06 16:19:16 -04:00
2020-03-18 12:15:32 -04:00
2019-02-08 10:43:38 -05:00
2019-01-16 12:32:32 -05:00
2018-07-05 11:22:33 +03:00
2018-07-31 19:46:00 -04:00
2018-07-05 11:22:33 +03:00
2018-07-03 16:34:52 +03:00
2019-01-16 12:32:32 -05:00

Tor protects your privacy on the internet by hiding the connection
between your Internet address and the services you use. We believe Tor
is reasonably secure, but please ensure you read the instructions and
configure it properly.

To build Tor from source:
        ./configure && make && make install

To build Tor from a just-cloned git repository:
        sh autogen.sh && ./configure && make && make install

Home page:
        https://www.torproject.org/

Download new versions:
        https://www.torproject.org/download/download.html

Documentation, including links to installation and setup instructions:
        https://www.torproject.org/docs/documentation.html

Making applications work with Tor:
        https://wiki.torproject.org/projects/tor/wiki/doc/TorifyHOWTO

Frequently Asked Questions:
        https://www.torproject.org/docs/faq.html


To get started working on Tor development:
        See the doc/HACKING directory.

Release timeline:
         https://trac.torproject.org/projects/tor/wiki/org/teams/NetworkTeam/CoreTorReleases
S
Description
No description provided
Readme 96 MiB
Languages
C 94.4%
Python 1.5%
C++ 1.1%
Shell 1.1%
M4 0.9%
Other 0.8%