[HICN-534] Major rework on libtransport organization

Change-Id: I361b83a18b4fd59be136d5f0817fc28e17e89884
Signed-off-by: Mauro Sardara <msardara@cisco.com>

1 files changed, 241 insertions, 0 deletions

diff --git a/libtransport/src/security/verifier.cc b/libtransport/src/security/verifier.cc
new file mode 100644
index 000000000..19796f718
--- /dev/null
+++ b/libtransport/src/security/verifier.cc
@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * 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.
+ */
+
+#include <hicn/transport/core/packet.h>
+#include <hicn/transport/errors/malformed_ahpacket_exception.h>
+#include <hicn/transport/portability/portability.h>
+#include <hicn/transport/security/key_id.h>
+#include <hicn/transport/security/verifier.h>
+#include <hicn/transport/utils/log.h>
+
+extern "C" {
+#ifndef _WIN32
+TRANSPORT_CLANG_DISABLE_WARNING("-Wextern-c-compat")
+#endif
+#include <hicn/hicn.h>
+}
+
+#include <sys/stat.h>
+
+namespace utils {
+
+TRANSPORT_ALWAYS_INLINE bool file_exists(const std::string &name) {
+  struct stat buffer;
+  return (stat(name.c_str(), &buffer) == 0);
+}
+
+uint8_t Verifier::zeros[200] = {0};
+
+Verifier::Verifier() {
+  parcSecurity_Init();
+  PARCInMemoryVerifier *in_memory_verifier = parcInMemoryVerifier_Create();
+  this->verifier_ =
+      parcVerifier_Create(in_memory_verifier, PARCInMemoryVerifierAsVerifier);
+}
+
+Verifier::~Verifier() {
+  if (key_) parcKey_Release(&key_);
+  if (keyId_) parcKeyId_Release(&keyId_);
+  if (signer_) parcSigner_Release(&signer_);
+  if (symmetricKeyStore_) parcSymmetricKeyStore_Release(&symmetricKeyStore_);
+  if (key_buffer_) parcBuffer_Release(&key_buffer_);
+  if (composer_) parcBufferComposer_Release(&composer_);
+  if (certificate_) parcCertificate_Release(&certificate_);
+  if (factory_) parcCertificateFactory_Release(&factory_);
+  if (verifier_) parcVerifier_Release(&verifier_);
+  parcSecurity_Fini();
+}
+
+/*
+ * TODO: Unsupported in libparc
+ */
+bool Verifier::hasKey(PARCKeyId *keyId) { return false; }
+
+/*
+ * TODO: signal errors without trap.
+ */
+bool Verifier::addKey(PARCKey *key) {
+  parcVerifier_AddKey(this->verifier_, key);
+  return true;
+}
+
+PARCKeyId *Verifier::addKeyFromPassphrase(const std::string &passphrase,
+                                          CryptoSuite suite) {
+  composer_ = parcBufferComposer_Create();
+  parcBufferComposer_PutString(composer_, passphrase.c_str());
+  key_buffer_ = parcBufferComposer_ProduceBuffer(composer_);
+
+  symmetricKeyStore_ = parcSymmetricKeyStore_Create(key_buffer_);
+  signer_ = parcSigner_Create(
+      parcSymmetricKeySigner_Create(
+          symmetricKeyStore_,
+          parcCryptoSuite_GetCryptoHash(static_cast<PARCCryptoSuite>(suite))),
+      PARCSymmetricKeySignerAsSigner);
+  keyId_ = parcSigner_CreateKeyId(signer_);
+  key_ = parcKey_CreateFromSymmetricKey(
+      keyId_, parcSigner_GetSigningAlgorithm(signer_), key_buffer_);
+
+  addKey(key_);
+  return keyId_;
+}
+
+PARCKeyId *Verifier::addKeyFromCertificate(const std::string &file_name) {
+  factory_ = parcCertificateFactory_Create(PARCCertificateType_X509,
+                                           PARCContainerEncoding_PEM);
+  parcAssertNotNull(factory_, "Expected non-NULL factory");
+
+  if (!file_exists(file_name)) {
+    TRANSPORT_LOGW("Warning! The certificate %s file does not exist",
+                   file_name.c_str());
+    return nullptr;
+  }
+
+  certificate_ = parcCertificateFactory_CreateCertificateFromFile(
+      factory_, (char *)file_name.c_str(), NULL);
+  PARCBuffer *derEncodedVersion =
+      parcCertificate_GetDEREncodedPublicKey(certificate_);
+  PARCCryptoHash *keyDigest = parcCertificate_GetPublicKeyDigest(certificate_);
+  keyId_ = parcKeyId_Create(parcCryptoHash_GetDigest(keyDigest));
+  key_ = parcKey_CreateFromDerEncodedPublicKey(keyId_, PARCSigningAlgorithm_RSA,
+                                               derEncodedVersion);
+
+  addKey(key_);
+  return keyId_;
+}
+
+int Verifier::verify(const Packet &packet) {
+  // to initialize packet.payload_head_
+  const_cast<Packet *>(&packet)->separateHeaderPayload();
+  bool valid = false;
+
+  // initialize packet.payload_head_
+  const_cast<Packet *>(&packet)->separateHeaderPayload();
+  // header chain points to the IP + TCP hicn header
+  // utils::MemBuf *header_chain = packet.header_head_;
+  // utils::MemBuf *payload_chain = packet.payload_head_;
+  // uint8_t *hicn_packet = header_chain->writableData();
+  Packet::Format format = packet.getFormat();
+
+  if (!(packet.format_ & HFO_AH)) {
+    throw errors::MalformedAHPacketException();
+  }
+
+  // Copy IP+TCP/ICMP header before zeroing them
+  hicn_header_t header_copy;
+  hicn_packet_copy_header(format, (const hicn_header_t *)packet.packet_start_,
+                          &header_copy, false);
+
+  PARCCryptoSuite suite =
+      static_cast<PARCCryptoSuite>(packet.getValidationAlgorithm());
+  PARCCryptoHashType hashtype = parcCryptoSuite_GetCryptoHash(suite);
+  KeyId _key_id = packet.getKeyId();
+  PARCBuffer *buffer =
+      parcBuffer_Wrap(_key_id.first, _key_id.second, 0, _key_id.second);
+  PARCKeyId *key_id = parcKeyId_Create(buffer);
+  parcBuffer_Release(&buffer);
+
+  int ah_payload_len = (int)packet.getSignatureSize();
+  uint8_t *_signature = packet.getSignature();
+  uint8_t *signature = new uint8_t[ah_payload_len];
+  // TODO Remove signature copy at this point, by not setting to zero
+  // the validation payload.
+  std::memcpy(signature, _signature, ah_payload_len);
+
+  std::shared_ptr<CryptoHasher> hasher;
+  switch (CryptoSuite(suite)) {
+    case CryptoSuite::DSA_SHA256:
+    case CryptoSuite::RSA_SHA256:
+    case CryptoSuite::RSA_SHA512:
+    case CryptoSuite::ECDSA_256K1: {
+      hasher = std::make_shared<CryptoHasher>(
+          parcVerifier_GetCryptoHasher(verifier_, key_id, hashtype));
+      break;
+    }
+    case CryptoSuite::HMAC_SHA256:
+    case CryptoSuite::HMAC_SHA512: {
+      if (!signer_) return false;
+      hasher =
+          std::make_shared<CryptoHasher>(parcSigner_GetCryptoHasher(signer_));
+      break;
+    }
+    default: { return false; }
+  }
+  CryptoHash hash_computed_locally = getPacketHash(packet, hasher);
+
+  PARCBuffer *bits =
+      parcBuffer_Wrap(signature, ah_payload_len, 0, ah_payload_len);
+  parcBuffer_Rewind(bits);
+
+  /* IF the signature algo is ECDSA, the signature might be shorter than the
+   * signature field */
+  PARCSigningAlgorithm algo = parcCryptoSuite_GetSigningAlgorithm(suite);
+  while (algo == PARCSigningAlgorithm_ECDSA && parcBuffer_HasRemaining(bits) &&
+         parcBuffer_GetUint8(bits) == 0)
+    ;
+
+  if (algo == PARCSigningAlgorithm_ECDSA) {
+    parcBuffer_SetPosition(bits, parcBuffer_Position(bits) - 1);
+  }
+
+  if (!parcBuffer_HasRemaining(bits)) {
+    parcKeyId_Release(&key_id);
+    parcBuffer_Release(&bits);
+    return valid;
+  }
+
+  PARCSignature *signatureToVerify = parcSignature_Create(
+      parcCryptoSuite_GetSigningAlgorithm(suite), hashtype, bits);
+
+  if (algo == PARCSigningAlgorithm_RSA) {
+    parcBuffer_SetPosition(bits, 0);
+  }
+
+  valid = parcVerifier_VerifyDigestSignature(
+      verifier_, key_id, hash_computed_locally.hash_, suite, signatureToVerify);
+
+  /* Restore the resetted fields */
+  hicn_packet_copy_header(format, &header_copy,
+                          (hicn_header_t *)packet.packet_start_, false);
+
+  delete[] signature;
+  parcKeyId_Release(&key_id);
+  parcBuffer_Release(&bits);
+  parcSignature_Release(&signatureToVerify);
+
+  return valid;
+}
+
+CryptoHash Verifier::getPacketHash(const Packet &packet,
+                                   std::shared_ptr<CryptoHasher> hasher) {
+  MemBuf *header_chain = packet.header_head_;
+  MemBuf *payload_chain = packet.payload_head_;
+  Packet::Format format = packet.getFormat();
+  int ah_payload_len = (int)packet.getSignatureSize();
+  uint8_t *hicn_packet = header_chain->writableData();
+  std::size_t header_len = Packet::getHeaderSizeFromFormat(format);
+
+  // Reset fields that should not appear in the signature
+  const_cast<Packet &>(packet).resetForHash();
+  hasher->init().updateBytes(hicn_packet, header_len + ah_payload_len);
+
+  for (MemBuf *current = payload_chain; current != header_chain;
+       current = current->next()) {
+    hasher->updateBytes(current->data(), current->length());
+  }
+
+  return hasher->finalize();
+}
+
+}  // namespace utils