kernel: dev: Add /dev/random

Introduce a prototype cryptographically secure (?) random number generator.

The RNG uses ChaCha20 seeded with a SipHash-processed entropy pool. Entropy is
collected only at read time and is mixed into the internal pool before each
ChaCha20 reseed. The design is still experimental.

Signed-off-by: Alex Funo <frost@osmora.org>
Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/sys/include/dev/random/siphash.h b/sys/include/dev/random/siphash.h
new file mode 100644
index 0000000..ecabb4a
--- /dev/null
+++ b/sys/include/dev/random/siphash.h
@@ -0,0 +1,34 @@
+/* <MIT License>
+ Copyright (c) 2013  Marek Majkowski <marek@popcount.org>
+
+ 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.
+ </MIT License>
+
+ Original location:
+    https://github.com/majek/csiphash/
+
+ Solution inspired by code from:
+    Samuel Neves (supercop/crypto_auth/siphash24/little)
+    djb (supercop/crypto_auth/siphash24/little2)
+    Jean-Philippe Aumasson (https://131002.net/siphash/siphash24.c)
+*/
+
+#include <stdint.h>
+
+uint64_t siphash24(const void *src, unsigned long src_sz, const char k[16]);