Merge commit '86cc97e55fe346502462284d2e636a2b3708163e' as 'Sources/OpenVPN3'

Sources/OpenVPN3/openvpn/applecrypto/crypto/hmac.hpp

@@ -0,0 +1,145 @@
+//    OpenVPN -- An application to securely tunnel IP networks
+//               over a single port, with support for SSL/TLS-based
+//               session authentication and key exchange,
+//               packet encryption, packet authentication, and
+//               packet compression.
+//
+//    Copyright (C) 2012-2017 OpenVPN Inc.
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Affero General Public License Version 3
+//    as published by the Free Software Foundation.
+//
+//    This program is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Affero General Public License for more details.
+//
+//    You should have received a copy of the GNU Affero General Public License
+//    along with this program in the COPYING file.
+//    If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef OPENVPN_APPLECRYPTO_CRYPTO_HMAC_H
+#define OPENVPN_APPLECRYPTO_CRYPTO_HMAC_H
+
+// Wrap the Apple HMAC API defined in <CommonCrypto/CommonHMAC.h> so that
+// it can be used as part of the crypto layer of the OpenVPN core.
+
+#include <string>
+#include <cstring>
+
+#include <CommonCrypto/CommonHMAC.h>
+
+#include <openvpn/common/size.hpp>
+#include <openvpn/common/exception.hpp>
+#include <openvpn/applecrypto/crypto/digest.hpp>
+
+namespace openvpn {
+  namespace AppleCrypto {
+    class HMACContext
+    {
+      HMACContext(const HMACContext&) = delete;
+      HMACContext& operator=(const HMACContext&) = delete;
+
+    public:
+      OPENVPN_EXCEPTION(digest_cannot_be_used_with_hmac);
+      OPENVPN_SIMPLE_EXCEPTION(hmac_uninitialized);
+      OPENVPN_SIMPLE_EXCEPTION(hmac_keysize_error);
+
+      enum {
+	MAX_HMAC_SIZE = DigestContext::MAX_DIGEST_SIZE,
+	MAX_HMAC_KEY_SIZE = 128,
+      };
+
+      HMACContext()
+      {
+	state = PRE;
+      }
+
+      HMACContext(const CryptoAlgs::Type digest, const unsigned char *key, const size_t key_size)
+      {
+	init(digest, key, key_size);
+      }
+
+      ~HMACContext()
+      {
+      }
+
+      void init(const CryptoAlgs::Type digest, const unsigned char *key, const size_t key_size)
+      {
+	state = PRE;
+	info = DigestContext::digest_type(digest);
+	digest_size_ = CryptoAlgs::size(digest);
+	hmac_alg = info->hmac_alg();
+	if (hmac_alg == DigestInfo::NO_HMAC_ALG)
+	  throw digest_cannot_be_used_with_hmac(info->name());
+	if (key_size > MAX_HMAC_KEY_SIZE)
+	  throw hmac_keysize_error();
+	std::memcpy(key_, key, key_size_ = key_size);
+	state = PARTIAL;
+      }
+
+      void reset() // Apple HMAC API is missing reset method, so we have to reinit
+      {
+	cond_reset(true);
+      }
+
+      void update(const unsigned char *in, const size_t size)
+      {
+	cond_reset(false);
+	CCHmacUpdate(&ctx, in, size);
+      }
+
+      size_t final(unsigned char *out)
+      {
+	cond_reset(false);
+	CCHmacFinal(&ctx, out);
+	return digest_size_;
+      }
+
+      size_t size() const
+      {
+	if (!is_initialized())
+	  throw hmac_uninitialized();
+	return digest_size_;
+      }
+
+      bool is_initialized() const
+      {
+	return state >= PARTIAL;
+      }
+
+    private:
+      void cond_reset(const bool force_init)
+      {
+	switch (state)
+	  {
+	  case PRE:
+	    throw hmac_uninitialized();
+	  case READY:
+	    if (!force_init)
+	      return;
+	  case PARTIAL:
+	    CCHmacInit(&ctx, hmac_alg, key_, key_size_);
+	    state = READY;
+	  }
+      }
+
+      enum State {
+	PRE=0,
+	PARTIAL,
+	READY
+      };
+      int state;
+
+      const DigestInfo *info;
+      CCHmacAlgorithm hmac_alg;
+      size_t key_size_;
+      size_t digest_size_;
+      unsigned char key_[MAX_HMAC_KEY_SIZE];
+      CCHmacContext ctx;
+    };
+  }
+}
+
+#endif