1 files changed, 88 insertions, 0 deletions
diff --git a/src/crypto/siphash.h b/src/crypto/siphash.h
new file mode 100644
index 0000000..90777b8
--- /dev/null
+++ b/src/crypto/siphash.h
@@ -0,0 +1,88 @@
+/* Copyright (C) 2015-2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * SipHash: a fast short-input PRF
+ * https://131002.net/siphash/
+ *
+ * This implementation is specifically for SipHash2-4.
+ */
+
+#ifndef SIPHASH_H
+#define SIPHASH_H
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+
+#define SIPHASH_ALIGNMENT 8
+typedef u64 siphash_key_t[2];
+
+u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t key);
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t key);
+#endif
+
+u64 siphash_1u64(const u64 a, const siphash_key_t key);
+u64 siphash_2u64(const u64 a, const u64 b, const siphash_key_t key);
+u64 siphash_3u64(const u64 a, const u64 b, const u64 c,
+		 const siphash_key_t key);
+u64 siphash_4u64(const u64 a, const u64 b, const u64 c, const u64 d,
+		 const siphash_key_t key);
+
+static inline u64 ___siphash_aligned(const u64 *data, size_t len, const siphash_key_t key)
+{
+	if (__builtin_constant_p(len) && len == 8)
+		return siphash_1u64(data[0], key);
+	if (__builtin_constant_p(len) && len == 16)
+		return siphash_2u64(data[0], data[1], key);
+	if (__builtin_constant_p(len) && len == 24)
+		return siphash_3u64(data[0], data[1], data[2], key);
+	if (__builtin_constant_p(len) && len == 32)
+		return siphash_4u64(data[0], data[1], data[2], data[3], key);
+	return __siphash_aligned(data, len, key);
+}
+
+/**
+ * siphash - compute 64-bit siphash PRF value
+ * @data: buffer to hash
+ * @size: size of @data
+ * @key: the siphash key
+ */
+static inline u64 siphash(const void *data, size_t len, const siphash_key_t key)
+{
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+	if (!IS_ALIGNED((unsigned long)data, SIPHASH_ALIGNMENT))
+		return __siphash_unaligned(data, len, key);
+#endif
+	return ___siphash_aligned(data, len, key);
+}
+
+static inline u64 siphash_2u32(const u32 a, const u32 b, const siphash_key_t key)
+{
+	return siphash_1u64((u64)b << 32 | a, key);
+}
+
+static inline u64 siphash_4u32(const u32 a, const u32 b, const u32 c, const u32 d,
+			       const siphash_key_t key)
+{
+	return siphash_2u64((u64)b << 32 | a, (u64)d << 32 | c, key);
+}
+
+static inline u64 siphash_6u32(const u32 a, const u32 b, const u32 c, const u32 d,
+			       const u32 e, const u32 f, const siphash_key_t key)
+{
+	return siphash_3u64((u64)b << 32 | a, (u64)d << 32 | c, (u64)f << 32 | e,
+			    key);
+}
+
+static inline u64 siphash_8u32(const u32 a, const u32 b, const u32 c, const u32 d,
+			       const u32 e, const u32 f, const u32 g, const u32 h,
+			       const siphash_key_t key)
+{
+	return siphash_4u64((u64)b << 32 | a, (u64)d << 32 | c, (u64)f << 32 | e,
+			    (u64)h << 32 | g, key);
+}
+
+#ifdef DEBUG
+bool siphash_selftest(void);
+#endif
+
+#endif /* SIPHASH_H */