Upgrade the random device to use a "real" hash instead of building

one out of a block cipher. This has 2 advantages:
1) The code is _much_ simpler
2) We aren't committing our security to one algorithm (much as we
   may think we trust AES).

While I'm here, make an explicit reseed do a slow reseed instead
of a fast; this is in line with what the original paper suggested.

1 files changed, 2 insertions, 6 deletions

diff --git a/sys/dev/random/hash.h b/sys/dev/random/hash.h
index 5a30821..b307bfc 100644
--- a/sys/dev/random/hash.h
+++ b/sys/dev/random/hash.h
@@ -26,14 +26,10 @@
  * $FreeBSD$
  */
 
-#define KEYSIZE		32		/* in bytes - 32 bytes == 256 bits */
+#define KEYSIZE		32		/* (in bytes) 32 bytes == 256 bits */
 
 struct yarrowhash {		/* Big! Make static! */
-	keyInstance hashkey;	/* Data cycles through here */
-	cipherInstance cipher;	/* Rijndael internal */
-	u_char hash[KEYSIZE];	/* Repeatedly encrypted */
-	char accum[KEYSIZE];	/* Accumulate partial chunks */
-	u_int partial;		/* Keep track of < KEYSIZE chunks */
+	SHA256_CTX	sha;
 };
 
 struct yarrowkey {		/* Big! Make static! */