Incorporate sha2 code from sphlib 3.0

Changes from upstream are limited to change #include paths so that I
can place header files and included "c" files in a subdirectory.  I
didn't keep the unit tests from sphlib but instead verified them by
running them manually.  I will implement the same tests using the
Pl_SHA2 pipeline except that sphlib's sha2 implementation supports
partial bytes, which I will not exercise in qpdf or our tests.

1 files changed, 27 insertions, 0 deletions

diff --git a/README b/README
index 2d82a22a..77e44600 100644
--- a/README
+++ b/README
@@ -48,6 +48,33 @@ obtained from
   http://www.efgh.com/software/rijndael.htm
   http://www.efgh.com/software/rijndael.txt
 
+The embedded sha2 code comes from sphlib 3.0
+
+  http://www.saphir2.com/sphlib/
+
+That code has the following license:
+
+  Copyright (c) 2007-2011  Projet RNRT SAPHIR
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
 
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