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

2026-04-24 00:00:05 +08:00 · 2020-02-24 14:43:11 +03:00
parent 133b3756e6 86cc97e55f
commit 32f1555929
655 changed files with 146468 additions and 0 deletions
@@ -0,0 +1,135 @@
+//    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/>.
+
+// Wrap the mbed TLS Cryptographic Random API defined in <mbedtls/ctr_drbg.h>
+// so that it can be used as the primary source of cryptographic entropy by
+// the OpenVPN core.
+
+#ifndef OPENVPN_MBEDTLS_UTIL_RAND_H
+#define OPENVPN_MBEDTLS_UTIL_RAND_H
+
+#include <mbedtls/entropy.h>
+#include <mbedtls/entropy_poll.h>
+#include <mbedtls/ctr_drbg.h>
+
+#include <openvpn/random/randapi.hpp>
+#include <openvpn/mbedtls/util/error.hpp>
+
+namespace openvpn {
+
+  class MbedTLSRandom : public RandomAPI
+  {
+  public:
+    OPENVPN_EXCEPTION(rand_error_mbedtls);
+
+    typedef RCPtr<MbedTLSRandom> Ptr;
+
+    MbedTLSRandom(const bool prng, RandomAPI::Ptr entropy_source)
+      : entropy(std::move(entropy_source))
+    {
+      // Init RNG context
+      mbedtls_ctr_drbg_init(&ctx);
+
+      // Seed RNG
+      const int errnum = mbedtls_ctr_drbg_seed(&ctx, entropy_poll, entropy.get(), nullptr, 0);
+      if (errnum < 0)
+	throw MbedTLSException("mbedtls_ctr_drbg_seed", errnum);
+
+      // If prng is set, configure for higher performance
+      // by reseeding less frequently.
+      if (prng)
+	mbedtls_ctr_drbg_set_reseed_interval(&ctx, 1000000);
+    }
+
+    MbedTLSRandom(const bool prng)
+      : MbedTLSRandom(prng, RandomAPI::Ptr()) { }
+
+    virtual ~MbedTLSRandom()
+    {
+      // Free RNG context
+      mbedtls_ctr_drbg_free(&ctx);
+    }
+
+    // Random algorithm name
+    virtual std::string name() const
+    {
+      const std::string n = "mbedTLS-CTR_DRBG";
+      if (entropy)
+	return n + '+' + entropy->name();
+      else
+	return n;
+    }
+
+    // Return true if algorithm is crypto-strength
+    virtual bool is_crypto() const
+    {
+      return true;
+    }
+
+    // Fill buffer with random bytes
+    virtual void rand_bytes(unsigned char *buf, size_t size)
+    {
+      const int errnum = rndbytes(buf, size);
+      if (errnum < 0)
+	throw MbedTLSException("mbedtls_ctr_drbg_random", errnum);
+    }
+
+    // Like rand_bytes, but don't throw exception.
+    // Return true on successs, false on fail.
+    virtual bool rand_bytes_noexcept(unsigned char *buf, size_t size)
+    {
+      return rndbytes(buf, size) >= 0;
+    }
+
+  private:
+    int rndbytes(unsigned char *buf, size_t size)
+    {
+      return mbedtls_ctr_drbg_random(&ctx, buf, size);
+    }
+
+    static int entropy_poll(void *arg, unsigned char *output, size_t len)
+    {
+      if (arg)
+      {
+	RandomAPI* entropy = (RandomAPI*)arg;
+	if (entropy->rand_bytes_noexcept(output, len))
+	  return 0;
+	else
+	  return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
+      }
+      else
+      {
+#ifndef OPENVPN_DISABLE_MBEDTLS_PLATFORM_ENTROPY_POLL
+	size_t olen;
+	return mbedtls_platform_entropy_poll(nullptr, output, len, &olen);
+#else
+	return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
+#endif
+      }
+    }
+
+    mbedtls_ctr_drbg_context ctx;
+    RandomAPI::Ptr entropy;
+  };
+
+}
+
+#endif