key-chain.hpp

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
#ifndef NDN_SECURITY_KEY_CHAIN_HPP
#define NDN_SECURITY_KEY_CHAIN_HPP

#include "identity-certificate.hpp"
#include "public-key.hpp"
#include "signature-sha256-with-rsa.hpp"
#include "signature-sha256.hpp"
#include "secured-bag.hpp"
#include "../interest.hpp"
#include "../util/random.hpp"
#include "../util/crypto.hpp"

//PublicInfo
#include "sec-public-info-sqlite3.hpp"
#include "sec-public-info-memory.hpp"
//TPM
#include "sec-tpm-file.hpp"
#include "sec-tpm-memory.hpp"

#ifdef NDN_CPP_HAVE_OSX_SECURITY
#include "sec-tpm-osx.hpp"
#endif


namespace ndn {

template<class Info, class Tpm>
class KeyChainImpl : public Info, public Tpm
{
  typedef SecPublicInfo::Error InfoError;
  typedef SecTpm::Error TpmError;
public:
  Name
  createIdentity(const Name& identityName)
  {
    Info::addIdentity(identityName);

    Name keyName;
    try
      {
        keyName = Info::getDefaultKeyNameForIdentity(identityName);
      }
    catch (InfoError& e)
      {
        keyName = generateRSAKeyPairAsDefault(identityName, true);
      }

    Name certName;
    try
      {
        certName = Info::getDefaultCertificateNameForKey(keyName);
      }
    catch (InfoError& e)
      {
        shared_ptr<IdentityCertificate> selfCert = selfSign(keyName);
        Info::addCertificateAsIdentityDefault(*selfCert);
        certName = selfCert->getName();
      }

    return certName;
  }

  Name
  generateRSAKeyPair(const Name& identityName, bool isKsk = false, int keySize = 2048)
  {
    return generateKeyPair(identityName, isKsk, KEY_TYPE_RSA, keySize);
  }

  Name
  generateRSAKeyPairAsDefault(const Name& identityName, bool isKsk = false, int keySize = 2048)
  {
    Name keyName = generateKeyPair(identityName, isKsk, KEY_TYPE_RSA, keySize);

    Info::setDefaultKeyNameForIdentity(keyName);

    return keyName;
  }

  shared_ptr<IdentityCertificate>
  prepareUnsignedIdentityCertificate(const Name& keyName,
                                     const Name& signingIdentity,
                                     const time::system_clock::TimePoint& notBefore,
                                     const time::system_clock::TimePoint& notAfter,
                                     const std::vector<CertificateSubjectDescription>& subjectDescription)

  {
    if (keyName.size() < 1)
      return shared_ptr<IdentityCertificate>();

    std::string keyIdPrefix = keyName.get(-1).toEscapedString().substr(0, 4);
    if (keyIdPrefix != "ksk-" && keyIdPrefix != "dsk-")
      return shared_ptr<IdentityCertificate>();

    shared_ptr<IdentityCertificate> certificate = make_shared<IdentityCertificate>();
    Name certName;

    if (signingIdentity.isPrefixOf(keyName))
      {
        certName.append(signingIdentity)
          .append("KEY")
          .append(keyName.getSubName(signingIdentity.size()))
          .append("ID-CERT")
          .appendVersion();
      }
    else
      {
        certName.append(keyName.getPrefix(-1))
          .append("KEY")
          .append(keyName.get(-1))
          .append("ID-CERT")
          .appendVersion();
      }

    certificate->setName(certName);
    certificate->setNotBefore(notBefore);
    certificate->setNotAfter(notAfter);

    shared_ptr<PublicKey> publicKey;
    try
      {
        publicKey = Info::getPublicKey(keyName);
      }
    catch (InfoError& e)
      {
        return shared_ptr<IdentityCertificate>();
      }
    certificate->setPublicKeyInfo(*publicKey);

    if (subjectDescription.empty())
      {
        CertificateSubjectDescription subDescryptName("2.5.4.41", keyName.getPrefix(-1).toUri());
        certificate->addSubjectDescription(subDescryptName);
      }
    else
      {
        std::vector<CertificateSubjectDescription>::const_iterator sdIt =
          subjectDescription.begin();
        std::vector<CertificateSubjectDescription>::const_iterator sdEnd =
          subjectDescription.end();
        for(; sdIt != sdEnd; sdIt++)
          certificate->addSubjectDescription(*sdIt);
      }

    certificate->encode();

    return certificate;
  }

  template<typename T>
  void
  sign(T& packet)
  {
    if (!static_cast<bool>(Info::defaultCertificate()))
      {
        Info::refreshDefaultCertificate();

        if (!static_cast<bool>(Info::defaultCertificate()))
          {
            Name defaultIdentity;
            try
              {
                defaultIdentity = Info::getDefaultIdentity();
              }
            catch (InfoError& e)
              {
                uint32_t random = random::generateWord32();
                defaultIdentity.append("tmp-identity")
                  .append(reinterpret_cast<uint8_t*>(&random), 4);
              }
            createIdentity(defaultIdentity);
            Info::setDefaultIdentity(defaultIdentity);
            Info::refreshDefaultCertificate();
          }
      }

    sign(packet, *Info::defaultCertificate());
  }

  template<typename T>
  void
  sign(T& packet, const Name& certificateName)
  {
    if (!Info::doesCertificateExist(certificateName))
      throw InfoError("Requested certificate [" + certificateName.toUri() + "] doesn't exist");

    SignatureSha256WithRsa signature;
    // implicit conversion should take care
    signature.setKeyLocator(certificateName.getPrefix(-1));

    // For temporary usage, we support RSA + SHA256 only, but will support more.
    signPacketWrapper(packet, signature,
                      IdentityCertificate::certificateNameToPublicKeyName(certificateName),
                      DIGEST_ALGORITHM_SHA256);
  }

  Signature
  sign(const uint8_t* buffer, size_t bufferLength, const Name& certificateName)
  {
    if (!Info::doesCertificateExist(certificateName))
      throw InfoError("Requested certificate [" + certificateName.toUri() + "] doesn't exist");

    Name keyName = IdentityCertificate::certificateNameToPublicKeyName(certificateName);

    SignatureSha256WithRsa signature;
    // implicit conversion should take care
    signature.setKeyLocator(certificateName.getPrefix(-1));

    // For temporary usage, we support RSA + SHA256 only, but will support more.
    signature.setValue(Tpm::signInTpm(buffer, bufferLength, keyName, DIGEST_ALGORITHM_SHA256));
    return signature;
  }

  template<typename T>
  void
  signByIdentity(T& packet, const Name& identityName)
  {
    Name signingCertificateName;
    try
      {
        signingCertificateName = Info::getDefaultCertificateNameForIdentity(identityName);
      }
    catch (InfoError& e)
      {
        signingCertificateName = createIdentity(identityName);
        // Ideally, no exception will be thrown out, unless something goes wrong in the TPM, which
        // is a fatal error.
      }

    // We either get or create the signing certificate, sign packet! (no exception unless fatal
    // error in TPM)
    sign(packet, signingCertificateName);
  }

  Signature
  signByIdentity(const uint8_t* buffer, size_t bufferLength, const Name& identityName)
  {
    Name signingCertificateName;
    try
      {
        signingCertificateName = Info::getDefaultCertificateNameForIdentity(identityName);
      }
    catch (InfoError& e)
      {
        signingCertificateName = createIdentity(identityName);
        // Ideally, no exception will be thrown out, unless something goes wrong in the TPM, which
        // is a fatal error.
      }

    // We either get or create the signing certificate, sign data! (no exception unless fatal error
    // in TPM)
    return sign(buffer, bufferLength, signingCertificateName);
  }

  void
  signWithSha256(Data& data)
  {
    SignatureSha256 sig;
    data.setSignature(sig);

    Block sigValue(Tlv::SignatureValue,
                   crypto::sha256(data.wireEncode().value(),
                                  data.wireEncode().value_size() -
                                  data.getSignature().getValue().size()));
    data.setSignatureValue(sigValue);
  }

  shared_ptr<IdentityCertificate>
  selfSign(const Name& keyName)
  {
    shared_ptr<PublicKey> pubKey;
    try
      {
        pubKey = Info::getPublicKey(keyName); // may throw an exception.
      }
    catch (InfoError& e)
      {
        return shared_ptr<IdentityCertificate>();
      }

    shared_ptr<IdentityCertificate> certificate = make_shared<IdentityCertificate>();

    Name certificateName = keyName.getPrefix(-1);
    certificateName.append("KEY").append(keyName.get(-1)).append("ID-CERT").appendVersion();

    certificate->setName(certificateName);
    certificate->setNotBefore(time::system_clock::now());
    certificate->setNotAfter(time::system_clock::now() + time::days(7300)/* ~20 years*/);
    certificate->setPublicKeyInfo(*pubKey);
    certificate->addSubjectDescription(CertificateSubjectDescription("2.5.4.41", keyName.toUri()));
    certificate->encode();

    selfSign(*certificate);
    return certificate;
  }

  void
  selfSign (IdentityCertificate& cert)
  {
    Name keyName = IdentityCertificate::certificateNameToPublicKeyName(cert.getName());
    if (!Tpm::doesKeyExistInTpm(keyName, KEY_CLASS_PRIVATE))
      throw TpmError("private key does not exist!");

    SignatureSha256WithRsa signature;
    signature.setKeyLocator(cert.getName().getPrefix(-1)); // implicit conversion should take care

    // For temporary usage, we support RSA + SHA256 only, but will support more.
    signPacketWrapper(cert, signature, keyName, DIGEST_ALGORITHM_SHA256);
  }

  void
  deleteCertificate (const Name& certificateName)
  {
    try
      {
        if (Info::getDefaultCertificateName() == certificateName)
          return;
      }
    catch (InfoError& e)
      {
        // Not a real error, just try to delete the certificate
      }

    Info::deleteCertificateInfo(certificateName);
  }

  void
  deleteKey (const Name& keyName)
  {
    try
      {
        if (Info::getDefaultKeyNameForIdentity(Info::getDefaultIdentity()) == keyName)
          return;
      }
    catch (InfoError& e)
      {
        // Not a real error, just try to delete the key
      }

    Info::deletePublicKeyInfo(keyName);
    Tpm::deleteKeyPairInTpm(keyName);
  }

  void
  deleteIdentity (const Name& identity)
  {
    try
      {
        if (Info::getDefaultIdentity() == identity)
          return;
      }
    catch (InfoError& e)
      {
        // Not a real error, just try to delete the identity
      }

    std::vector<Name> nameList;
    Info::getAllKeyNamesOfIdentity(identity, nameList, true);
    Info::getAllKeyNamesOfIdentity(identity, nameList, false);

    Info::deleteIdentityInfo(identity);

    std::vector<Name>::const_iterator it = nameList.begin();
    for(; it != nameList.end(); it++)
      Tpm::deleteKeyPairInTpm(*it);
  }

  shared_ptr<SecuredBag>
  exportIdentity(const Name& identity, const std::string& passwordStr)
  {
    if (!Info::doesIdentityExist(identity))
      throw InfoError("Identity does not exist!");

    Name keyName = Info::getDefaultKeyNameForIdentity(identity);

    ConstBufferPtr pkcs5;
    try
      {
        pkcs5 = Tpm::exportPrivateKeyPkcs5FromTpm(keyName, passwordStr);
      }
    catch (TpmError& e)
      {
        throw InfoError("Fail to export PKCS5 of private key");
      }

    shared_ptr<IdentityCertificate> cert;
    try
      {
        cert = Info::getCertificate(Info::getDefaultCertificateNameForKey(keyName));
      }
    catch (InfoError& e)
      {
        cert = selfSign(keyName);
        Info::addCertificateAsIdentityDefault(*cert);
      }

    shared_ptr<SecuredBag> secureBag = make_shared<SecuredBag>(boost::cref(*cert),
                                                               boost::cref(pkcs5));

    return secureBag;
  }

  void
  importIdentity(const SecuredBag& securedBag, const std::string& passwordStr)
  {
    Name certificateName = securedBag.getCertificate().getName();
    Name keyName = IdentityCertificate::certificateNameToPublicKeyName(certificateName);
    Name identity = keyName.getPrefix(-1);

    // Add identity
    Info::addIdentity(identity);

    // Add key
    Tpm::importPrivateKeyPkcs5IntoTpm(keyName,
                                      securedBag.getKey()->buf(),
                                      securedBag.getKey()->size(),
                                      passwordStr);

    shared_ptr<PublicKey> pubKey = Tpm::getPublicKeyFromTpm(keyName.toUri());
    // HACK! We should set key type according to the pkcs8 info.
    Info::addPublicKey(keyName, KEY_TYPE_RSA, *pubKey);
    Info::setDefaultKeyNameForIdentity(keyName);

    // Add cert
    Info::addCertificateAsIdentityDefault(securedBag.getCertificate());
  }


private:
  template<typename T>
  void
  sign(T& packet, const IdentityCertificate& certificate)
  {
    SignatureSha256WithRsa signature;
    signature.setKeyLocator(certificate.getName().getPrefix(-1));

    // For temporary usage, we support RSA + SHA256 only, but will support more.
    signPacketWrapper(packet, signature, certificate.getPublicKeyName(), DIGEST_ALGORITHM_SHA256);
  }

  Name
  generateKeyPair(const Name& identityName, bool isKsk = false,
                  KeyType keyType = KEY_TYPE_RSA, int keySize = 2048)
  {
    Name keyName = Info::getNewKeyName(identityName, isKsk);

    Tpm::generateKeyPairInTpm(keyName.toUri(), keyType, keySize);

    shared_ptr<PublicKey> pubKey = Tpm::getPublicKeyFromTpm(keyName.toUri());
    Info::addPublicKey(keyName, keyType, *pubKey);

    return keyName;
  }

  void
  signPacketWrapper(Data& data, const SignatureSha256WithRsa& signature,
                    const Name& keyName, DigestAlgorithm digestAlgorithm)
  {
    data.setSignature(signature);
    data.setSignatureValue(Tpm::signInTpm(data.wireEncode().value(),
                                          data.wireEncode().value_size() -
                                          data.getSignature().getValue().size(),
                                          keyName, digestAlgorithm));
  }

  void
  signPacketWrapper(Interest& interest, const SignatureSha256WithRsa& signature,
                    const Name& keyName, DigestAlgorithm digestAlgorithm)
  {
    Name signedName = interest.getName();
    signedName.append(signature.getInfo());

    Block sigValue = Tpm::signInTpm(signedName.wireEncode().value(),
                                    signedName.wireEncode().value_size(),
                                    keyName,
                                    DIGEST_ALGORITHM_SHA256);
    sigValue.encode();
    signedName.append(sigValue);
    interest.setName(signedName);
  }

};

} // namespace ndn



#if defined(NDN_CPP_HAVE_OSX_SECURITY) and defined(NDN_CPP_WITH_OSX_KEYCHAIN)

namespace ndn {

typedef KeyChainImpl<SecPublicInfoSqlite3, SecTpmOsx> KeyChain;

} // namespace ndn

#else

namespace ndn {

typedef KeyChainImpl<SecPublicInfoSqlite3, SecTpmFile> KeyChain;

} // namespace ndn

#endif //NDN_CPP_HAVE_OSX_SECURITY

#endif //NDN_SECURITY_KEY_CHAIN_HPP