Add support for parameterized SipHash

The core SipHash supports either 8 or 16-byte output and a configurable
number of rounds.
The default behavior, as added to EVP, is to use 16-byte output and
2,4 rounds, which matches the behavior of most implementations.
There is an EVP_PKEY_CTRL that can control the output size.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2216)

1 files changed, 24 insertions, 0 deletions

diff --git a/crypto/include/internal/siphash.h b/crypto/include/internal/siphash.h
new file mode 100644
index 0000000000..e086859622
--- /dev/null
+++ b/crypto/include/internal/siphash.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <stddef.h>
+
+#define SIPHASH_BLOCK_SIZE        8
+#define SIPHASH_KEY_SIZE         16
+#define SIPHASH_MIN_DIGEST_SIZE   8
+#define SIPHASH_MAX_DIGEST_SIZE  16
+
+typedef struct siphash_st SIPHASH;
+
+size_t SipHash_ctx_size(void);
+size_t SipHash_hash_size(SIPHASH *ctx);
+int SipHash_Init(SIPHASH *ctx, const unsigned char *k, int hash_size,
+                 int crounds, int drounds);
+void SipHash_Update(SIPHASH *ctx, const unsigned char *in, size_t inlen);
+int SipHash_Final(SIPHASH *ctx, unsigned char *out, size_t outlen);