ECIES: add ECIES-KEM. This version supports HKDF and ECDH with NIST curves.

Change-Id: I5af3215e96bb015049574aa18327cd7f7499dbd3

1 files changed, 61 insertions, 0 deletions

diff --git a/ecies_kem.h b/ecies_kem.h
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+++ b/ecies_kem.h
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+/*
+ * Copyright 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SYSTEM_KEYMASTER_ECIES_KEM_H_
+#define SYSTEM_KEYMASTER_ECIES_KEM_H_
+
+#include "kem.h"
+
+#include <UniquePtr.h>
+#include <openssl/ec.h>
+
+#include <keymaster/authorization_set.h>
+
+#include "hkdf.h"
+#include "key_exchange.h"
+
+namespace keymaster {
+
+/**
+ * EciesKem is an implementation of the key encapsulation mechanism ECIES-KEM described in
+ * ISO 18033-2 (http://www.shoup.net/iso/std6.pdf, http://www.shoup.net/papers/iso-2_1.pdf).
+ */
+class EciesKem : public Kem {
+  public:
+    virtual ~EciesKem() override {}
+    EciesKem(const AuthorizationSet& kem_description, keymaster_error_t* error);
+
+    /* Kem interface. */
+    bool Encrypt(const Buffer& peer_public_value, Buffer* output_clear_key,
+                 Buffer* output_encrypted_key) override;
+    bool Encrypt(const uint8_t* peer_public_value, size_t peer_public_value_len,
+                 Buffer* output_clear_key, Buffer* output_encrypted_key) override;
+
+    bool Decrypt(EC_KEY* private_key, const Buffer& encrypted_key, Buffer* output_key) override;
+    bool Decrypt(EC_KEY* private_key, const uint8_t* encrypted_key, size_t encrypted_key_len,
+                 Buffer* output_key) override;
+
+  private:
+    UniquePtr<KeyExchange> key_exchange_;
+    UniquePtr<Rfc5869Sha256Kdf> kdf_;
+    bool single_hash_mode_;
+    uint32_t key_bytes_to_generate_;
+    keymaster_ec_curve_t curve_;
+};
+
+}  // namespace keymaster
+
+#endif  // SYSTEM_KEYMASTER_ECIES_KEM_H_