util: import sha1 implementation from OpenBSD17.0-branchpoint

At the moment we support 5+ different implementations each with varying
amount of bugs - from thread safely problems [1], to outright broken
implementation(s) [2]

In order to accommodate these we have 150+ lines of configure script and
extra two configure toggles. Whist an actual implementation being
~200loc and our current compat wrapping ~250.

Let's not forget that different people use different code paths, thus
effectively makes it harder to test and debug since the default
implementation is automatically detected.

To minimise all these lovely experiences, import the "100% Public
Domain" OpenBSD sha1 implementation. Clearly document any changes needed
to get building correctly, since many/most of those can be upstreamed
making future syncs easier.

As an added bonus this will avoid all the 'fun' experiences trying to
integrate it with the Android and SCons builds.

v2: Manually expand __BEGIN_DECLS/__END_DECLS and document (Tapani).

Furthermore it seems that some games (or surrounding runtime) static
link against OpenSSL resulting in conflicts. For more information see
the discussion thread [3]

Bugzilla [1]: https://bugs.freedesktop.org/show_bug.cgi?id=94904
Bugzilla [2]: https://bugs.freedesktop.org/show_bug.cgi?id=97967
[3] https://lists.freedesktop.org/archives/mesa-dev/2017-January/140748.html
Cc: Mark Janes <[email protected]>
Cc: Vinson Lee <[email protected]>
Cc: Tapani Pälli <[email protected]>
Cc: Jonathan Gray <[email protected]>
Tested-by: Jonathan Gray <[email protected]>
Signed-off-by: Emil Velikov <[email protected]>
Acked-by: Tapani Pälli <[email protected]> (v1)
Acked-by: Jason Ekstrand <[email protected]> (v1)

1 files changed, 59 insertions, 0 deletions

diff --git a/src/util/sha1/README b/src/util/sha1/README
new file mode 100644
index 00000000000..f13baf9d1a8
--- /dev/null
+++ b/src/util/sha1/README
@@ -0,0 +1,59 @@
+This local copy of a SHA1 implementation based on the sources below.
+
+Why:
+ - Some libraries suffer from race condition and other issues. For example see
+commit ade3108bb5b0 ("util: Fix race condition on libgcrypt initialization").
+
+ - Fold the handling and detection of _eight_ implementations at configure
+stage and _seven_ different codepaths.
+
+ - Have a single, uniform, code used by developers, testers and users.
+
+ - Avoid conflicts when using software which ships with it's own SHA1 library.
+The latter of which conflicting with the one mesa is build against.
+
+
+
+Source:
+The SHA1 implementation is copied verbatim from the following links.
+At the time of checkout HEAD is 1.25 and 1.24 respectively.
+
+http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/lib/libc/hash/sha1.c?rev=HEAD
+http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/include/sha1.h?rev=HEAD
+
+
+Notes:
+ - The files should not have any local changes. If there are any they should be
+clearly documented below and one should aim to upstream them where possible.
+ 
+ - Files will be periodically syncronised with the respective upstream sources.
+Updates will be made regularly, but since the code is _not_ aimed as a
+cryptography solution any issues found should not be considered security ones.
+
+
+Local changes:
+ - Removed __bounded__ attribute qualifiers. Unavailable on platforms targeted
+by Mesa. Upstream status: TBD (N/A ?)
+
+ - Pick the sha1.h header from the current folder, by using "" over <> in the
+include directive. Upstream status: TBD
+
+ - Remove unused function prototypes - SHA1End, SHA1File, SHA1FileChunk and
+SHA1Data. Upstream status: TBD
+
+ - Use stdint.h integer types - u_int{8,16,32}_t -> uint{8,16,32}_t and
+u_int -> uint32_t, change header include. Upstream status: TBD
+
+ - Revert sha1.c rev 1.26 change (introduce DEF_WEAK).
+Upstream status: TBD (N/A ?)
+
+ - Add stdint.h include in sha1.h for uint*_t types. Upstream status: TBD
+
+ - Add stddef.h include in sha1.h for size_t type. Upstream status: TBD
+
+ - Use memset over explicit_bzero, since memset_s once isn't widely available.
+Upstream status: TBD (N/A ?)
+
+ - Manually expand __BEGIN_DECLS/__END_DECLS and make sure that they include
+the struct declaration.
+Upstream status: TBD