-doh and -dot mode use uTLS to camouflage their TLS Client Hello
fingerprint. The fingerprint to use is chosen randomly from a weighted
distribution. You can control this distribution using the new -utls
option. This change means that it is no longer possible to use a proxy
in -doh mode by setting the HTTP_PROXY or HTTPS_PROXY environment
variables; this was an undocumented side effect of using the Go net/http
package with no TLS camouflage.


## v1.20210812.0

Fixed an injection vulnerability in the dnstt-server log message
"NXDOMAIN: not authoritative for %s". This log message contains a
potentially attacker-controlled name. Because DNS labels may contain any
byte value, the log message allowed an attacker to write arbitrary bytes
to the dnstt-server log, with a variety of effects:
* A label containing a newline could break the format of the log, or be
  used to inject false log lines.
* Log output to a terminal could contain terminal escape sequences which
  could, for example, change the color of text, or have worse effects
  with older terminal emulators (https://seclists.org/bugtraq/2003/Feb/315).
* DNS names with a label that contained the dot character (\x2e) would
  be logged in an ambiguous way, with the intra-label dot appearing as a
  label separator.
DNS names are now logged using backslash hex escapes for unusual bytes.
This vulnerability was called to mind by "Injection Attacks Reloaded:
Tunnelling Malicious Payloads over DNS" by Jeitner and Shulman.
https://www.usenix.org/conference/usenixsecurity21/presentation/jeitner

Inhibited some "io: read/write on closed pipe" log messages.


## v1.20210803.0

Performance tuning. Enlarge some buffers and network receive windows to
permit faster downloads in some configurations. Adjusted the dynamic
polling model to work more as intended, and tweaked the server send loop
to continue bundling outgoing packets as long as some are immediately
available.

Reduce idle timeout from 10 minutes to 2 minutes. Terminated sessions
will be reclaimed more quickly.

Documentation updates.


## v0.20210424.0

dnstt was part of a software security audit done by Cure53. The report
found issues of severity levels Low–Medium in dnstt and in one of its
dependencies, a package used for Noise cryptography. This release fixes
the following issues:
 * UCB-02-002: Memory leak in acceptStreams() routine of dnstt server (Low)
 * UCB-02-003: Potential nonce overflow in Noise protocol (Medium)
 * UCB-02-004: Deprecated DH25519 Golang API used by Noise (Low)
 * UCB-02-006: DoS due to unconditional nonce increment (Low)
 * UCB-02-007: DoS due to missing socket timeouts (Low)
Unaddressed in this release are:
 * UCB-02-005: Client ID security considerations & Noise authenticated data (Low)
 * UCB-02-008: Lack of rate limiting in Snowflake and dnstt (Info)
Two other issues in the report, UCB-02-001 and UCB-02-009, do not have
to do with dnstt. For more details and the text of the report, see
https://www.bamsoftware.com/software/dnstt/security.html#cure53-turbotunnel-2021

Added man pages for dnstt-client and dnstt-server.


## v0.20200506.0

Documentation updates.


## v0.20200504.0

Documentation updates and link to web page.
https://www.bamsoftware.com/software/dnstt/


## v0.20200430.0

Send leftover packets (those that were too big to fit in the current DNS
response) to the correct client in the future. Before, such leftover
packets were included in the next response to be sent, regardless of the
client it was intended for.

Fix the loop that packs packets into responses in the server. Before, if
there were not a packet immediately available, the response would always
be empty. Now, a packet has until the response timeout to be included.

Buffer the DoT transport in the client so that length prefixes and DNS
queries happen in the same send.

Don't look for encoded packets in a response that was too short to
contain a ClientID.


## v0.20200426.0

Added the -mtu command-line option to the server.

Documentation fixes.


## v0.20200419.0

Initial public release and announcement.
https://github.com/net4people/bbs/issues/30