The recently added TLS client session cache used
SSL_SESSION_is_resumable() to avoid polluting the cache with
non-resumable sessions. However, it turned out that we cannot provide
a shim for this function across the whole range of OpenSSL versions
due to the fact that OpenSSL 1.1.0 does uses opaque pointers for
SSL_SESSION objects.
The commit replaces the shim for SSL_SESSION_is_resumable() with a non
public approximation of it on systems shipped with OpenSSL 1.1.0. It
is not turned into a proper shim because it does not fully emulate the
behaviour of SSL_SESSION_is_resumable(), but in our case it is good
enough, as it still helps to protect the cache from pollution.
For systems shipped with OpenSSL 1.0.X and derivatives (e.g. older
versions of LibreSSL), the provided replacement perfectly mimics the
function it is intended to replace.
The implementation is done on top of the reference counting
functionality found in OpenSSL/LibreSSL, which allows for avoiding
wrapping the object.
Adding this function allows using reference counting for TLS contexts
in BIND 9's codebase.
This commit converts the license handling to adhere to the REUSE
specification. It specifically:
1. Adds used licnses to LICENSES/ directory
2. Add "isc" template for adding the copyright boilerplate
3. Changes all source files to include copyright and SPDX license
header, this includes all the C sources, documentation, zone files,
configuration files. There are notes in the doc/dev/copyrights file
on how to add correct headers to the new files.
4. Handle the rest that can't be modified via .reuse/dep5 file. The
binary (or otherwise unmodifiable) files could have license places
next to them in <foo>.license file, but this would lead to cluttered
repository and most of the files handled in the .reuse/dep5 file are
system test files.
This prevents a direct leak in OPENSSL_init_crypto (called from
OPENSSL_init_ssl).
Add shim version of OPENSSL_cleanup because it is missing in LibreSSL on
OpenBSD.
The EVP_MD_CTX_new() and EVP_MD_CTX_free() functions are renamed APIs
which were previously available as EVP_MD_CTX_create() and
EVP_MD_CTX_destroy() respectively, which means that we can use them
instead of providing our own shim functions.
* Following the example set in 634bdfb16d8, the tlsdns netmgr
module now uses libuv and SSL primitives directly, rather than
opening a TLS socket which opens a TCP socket, as the previous
model was difficult to debug. Closes#2335.
* Remove the netmgr tls layer (we will have to re-add it for DoH)
* Add isc_tls API to wrap the OpenSSL SSL_CTX object into libisc
library; move the OpenSSL initialization/deinitialization from dstapi
needed for OpenSSL 1.0.x to the isc_tls_{initialize,destroy}()
* Add couple of new shims needed for OpenSSL 1.0.x
* When LibreSSL is used, require at least version 2.7.0 that
has the best OpenSSL 1.1.x compatibility and auto init/deinit
* Enforce OpenSSL 1.1.x usage on Windows
* Added a TLSDNS unit test and implemented a simple TLSDNS echo
server and client.
