3 files changed, 142 insertions, 0 deletions
diff --git a/src/crypto/CMakeLists.txt b/src/crypto/CMakeLists.txt
index 84f002929..d22d59b36 100644
--- a/src/crypto/CMakeLists.txt
+++ b/src/crypto/CMakeLists.txt
@@ -39,6 +39,7 @@ set(crypto_sources
   hash-extra-jh.c
   hash-extra-skein.c
   hash.c
+  hmac-keccak.c
   jh.c
   keccak.c
   oaes_lib.c
@@ -64,6 +65,7 @@ set(crypto_private_headers
   groestl_tables.h
   hash-ops.h
   hash.h
+  hmac-keccak.h
   initializer.h
   jh.h
   keccak.h
diff --git a/src/crypto/hmac-keccak.c b/src/crypto/hmac-keccak.c
new file mode 100644
index 000000000..edcb2065e
--- /dev/null
+++ b/src/crypto/hmac-keccak.c
@@ -0,0 +1,81 @@
+// Copyright (c) 2014-2018, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "hmac-keccak.h"
+#include "memwipe.h"
+
+#define KECCAK_BLOCKLEN 136
+#define HASH_SIZE 32
+
+void hmac_keccak_init(hmac_keccak_state *S, const uint8_t *_key, size_t keylen) {
+  const uint8_t *key = _key;
+  uint8_t keyhash[HASH_SIZE];
+  uint8_t pad[KECCAK_BLOCKLEN];
+  uint64_t i;
+
+  if (keylen > KECCAK_BLOCKLEN) {
+    keccak(key, keylen, keyhash, HASH_SIZE);
+    key = keyhash;
+    keylen = HASH_SIZE;
+  }
+
+  keccak_init(&S->inner);
+  memset(pad, 0x36, KECCAK_BLOCKLEN);
+  for (i = 0; i < keylen; ++i) {
+    pad[i] ^= key[i];
+  }
+  keccak_update(&S->inner, pad, KECCAK_BLOCKLEN);
+
+  keccak_init(&S->outer);
+  memset(pad, 0x5c, KECCAK_BLOCKLEN);
+  for (i = 0; i < keylen; ++i) {
+    pad[i] ^= key[i];
+  }
+  keccak_update(&S->outer, pad, KECCAK_BLOCKLEN);
+
+  memwipe(keyhash, HASH_SIZE);
+}
+
+void hmac_keccak_update(hmac_keccak_state *S, const uint8_t *data, size_t datalen) {
+  keccak_update(&S->inner, data, datalen);
+}
+
+void hmac_keccak_finish(hmac_keccak_state *S, uint8_t *digest) {
+  uint8_t ihash[HASH_SIZE];
+  keccak_finish(&S->inner, ihash);
+  keccak_update(&S->outer, ihash, HASH_SIZE);
+  keccak_finish(&S->outer, digest);
+  memwipe(ihash, HASH_SIZE);
+}
+
+void hmac_keccak_hash(uint8_t *out, const uint8_t *key, size_t keylen, const uint8_t *in, size_t inlen) {
+  hmac_keccak_state S;
+  hmac_keccak_init(&S, key, keylen);
+  hmac_keccak_update(&S, in, inlen);
+  hmac_keccak_finish(&S, out);
+}
diff --git a/src/crypto/hmac-keccak.h b/src/crypto/hmac-keccak.h
new file mode 100644
index 000000000..c450860d4
--- /dev/null
+++ b/src/crypto/hmac-keccak.h
@@ -0,0 +1,59 @@
+// Copyright (c) 2014-2018, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef HMAC_KECCAK_H
+#define HMAC_KECCAK_H
+
+#include "keccak.h"
+
+// HMAC RFC 2104 with Keccak-256 base hash function
+//
+// B = KECCAK_BLOCKLEN = 136 B
+// L = HASH_SIZE = 32 B
+//
+// Note this is not HMAC-SHA3 as SHA3 and Keccak differs in
+// the padding constant.
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+  KECCAK_CTX inner;
+  KECCAK_CTX outer;
+} hmac_keccak_state;
+
+void hmac_keccak_init(hmac_keccak_state *S, const uint8_t *_key, size_t keylen);
+void hmac_keccak_update(hmac_keccak_state *S, const uint8_t *data, size_t datalen);
+void hmac_keccak_finish(hmac_keccak_state *S, uint8_t *digest);
+void hmac_keccak_hash(uint8_t *out, const uint8_t *key, size_t keylen, const uint8_t *in, size_t inlen);
+
+#ifdef __cplusplus
+}
+#endif
+#endif //HMAC_KECCAK_H