Cleanup, MIT license

LICENSE

@@ -0,0 +1,20 @@
+Copyright 2018 Steven Dee
+
+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.

README.md

@@ -1,4 +1,8 @@
-libent is a simple cross-platform entropy gathering library. It tries
-to use the best available source of randomness, and is meant to be used
-in applications that need high-quality entropy, e.g. for generating
-cryptographic keys.
+libent is a cross-platform wrapper around `getentropy(2)`. It exports
+one symbol, `ent_getentropy`, which expands to `getentropy` if the
+latter is available. Otherwise, it tries to use the next best source of
+entropy -- /dev/urandom on *nix, BCryptGenRandom on Windows.
+
+References:
+* [OpenBSD getentropy](https://man.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man2/getentropy.2)
+* [djb on entropy gathering](https://blog.cr.yp.to/20140205-entropy.html)

include/ent/ent.h

@@ -1,10 +1,10 @@
 #ifndef _ENT_H
 #define _ENT_H
 
-#include <ent/config.h>
-
 #include <stddef.h>
 
+#include <ent/config.h>
+
 #if defined(ENT_GETENTROPY)
 # if defined(ENT_GE_SYSRANDOM)
 #   include <inttypes.h>  /* OSX sys/random.h needs Availability.h from this */
@@ -32,4 +32,16 @@ ent_getentropy(void* buf, size_t buflen);
 # error "libent: platform not supported"
 #endif
 
+#ifdef ENT_GETENTROPY
+#undef ENT_GETENTROPY
+#endif
+
+#ifdef ENT_GE_SYSRANDOM
+#undef ENT_GE_SYSRANDOM
+#endif
+
+#ifdef ENT_GE_UNISTD
+#undef ENT_GE_UNISTD
+#endif
+
 #endif /* _ENT_H */