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, 16 insertions, 1 deletions

diff --git a/crypto/evp/p_lib.c b/crypto/evp/p_lib.c
index 047e832637..b5e5206778 100644
--- a/crypto/evp/p_lib.c
+++ b/crypto/evp/p_lib.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 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
@@ -263,6 +263,21 @@ const unsigned char *EVP_PKEY_get0_poly1305(const EVP_PKEY *pkey, size_t *len)
 }
 #endif
 
+#ifndef OPENSSL_NO_SIPHASH
+const unsigned char *EVP_PKEY_get0_siphash(const EVP_PKEY *pkey, size_t *len)
+{
+    ASN1_OCTET_STRING *os = NULL;
+
+    if (pkey->type != EVP_PKEY_SIPHASH) {
+        EVPerr(EVP_F_EVP_PKEY_GET0_SIPHASH, EVP_R_EXPECTING_A_SIPHASH_KEY);
+        return NULL;
+    }
+    os = EVP_PKEY_get0(pkey);
+    *len = os->length;
+    return os->data;
+}
+#endif
+
 #ifndef OPENSSL_NO_RSA
 int EVP_PKEY_set1_RSA(EVP_PKEY *pkey, RSA *key)
 {