From f2e4bb875741843f17c0061756e4aea56968ec21 Mon Sep 17 00:00:00 2001
From: Neale Pickett <neale@lanl.gov>
Date: Wed, 19 Jan 2011 17:21:07 -0700
Subject: [PATCH] Add arc4 hashing

---
 include/arc4.c | 13 +++++++++++++
 include/arc4.h |  5 ++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/include/arc4.c b/include/arc4.c
index 63306ad..32d706b 100644
--- a/include/arc4.c
+++ b/include/arc4.c
@@ -51,3 +51,16 @@ arc4_crypt_buffer(uint8_t const *key, size_t keylen,
   arc4_init(&ctx, key, keylen);
   arc4_crypt(&ctx, buf, buf, buflen);
 }
+
+void
+arc4_hash(uint8_t const *buf, size_t buflen,
+          uint8_t *hash)
+{
+  struct arc4_ctx ctx;
+  int             i;
+
+  arc4_init(&ctx, buf, buflen);
+  for (i = 0; i < ARC4_HASHLEN; i += 1) {
+    hash[i] = arc4_pad(&ctx);
+  }
+}
diff --git a/include/arc4.h b/include/arc4.h
index 7aa7428..c917184 100644
--- a/include/arc4.h
+++ b/include/arc4.h
@@ -4,6 +4,8 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+#define ARC4_HASHLEN 16
+
 struct arc4_ctx {
   uint8_t S[256];
   uint8_t i;
@@ -16,5 +18,6 @@ void arc4_crypt(struct arc4_ctx *ctx,
                 uint8_t *obuf, uint8_t const *ibuf, size_t buflen);
 void arc4_crypt_buffer(uint8_t const *key, size_t keylen,
                        uint8_t *buf, size_t buflen);
-
+void arc4_hash(uint8_t const *buf, size_t buflen,
+               uint8_t *hash);
 #endif