src/util/sha1/README

   1 This local copy of a SHA1 implementation based on the sources below.
   2
   3 Why:
   4  - Some libraries suffer from race condition and other issues. For example see
   5 commit ade3108bb5b0 ("util: Fix race condition on libgcrypt initialization").
   6
   7  - Fold the handling and detection of _eight_ implementations at configure
   8 stage and _seven_ different codepaths.
   9
  10  - Have a single, uniform, code used by developers, testers and users.
  11
  12  - Avoid conflicts when using software which ships with it's own SHA1 library.
  13 The latter of which conflicting with the one mesa is build against.
  14
  15
  16
  17 Source:
  18 The SHA1 implementation is copied verbatim from the following links.
  19 At the time of checkout HEAD is 1.25 and 1.24 respectively.
  20
  21 http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/lib/libc/hash/sha1.c?rev=HEAD
  22 http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/include/sha1.h?rev=HEAD
  23
  24
  25 Notes:
  26  - The files should not have any local changes. If there are any they should be
  27 clearly documented below and one should aim to upstream them where possible.
  28
  29  - Files will be periodically syncronised with the respective upstream sources.
  30 Updates will be made regularly, but since the code is _not_ aimed as a
  31 cryptography solution any issues found should not be considered security ones.
  32
  33
  34 Local changes:
  35  - Removed __bounded__ attribute qualifiers. Unavailable on platforms targeted
  36 by Mesa. Upstream status: TBD (N/A ?)
  37
  38  - Pick the sha1.h header from the current folder, by using "" over <> in the
  39 include directive. Upstream status: TBD
  40
  41  - Remove unused function prototypes - SHA1End, SHA1File, SHA1FileChunk and
  42 SHA1Data. Upstream status: TBD
  43
  44  - Use stdint.h integer types - u_int{8,16,32}_t -> uint{8,16,32}_t and
  45 u_int -> uint32_t, change header include. Upstream status: TBD
  46
  47  - Revert sha1.c rev 1.26 change (introduce DEF_WEAK).
  48 Upstream status: TBD (N/A ?)
  49
  50  - Add stdint.h include in sha1.h for uint*_t types. Upstream status: TBD
  51
  52  - Add stddef.h include in sha1.h for size_t type. Upstream status: TBD
  53
  54  - Use memset over explicit_bzero, since memset_s once isn't widely available.
  55 Upstream status: TBD (N/A ?)
  56
  57  - Manually expand __BEGIN_DECLS/__END_DECLS and make sure that they include
  58 the struct declaration.
  59 Upstream status: TBD