Decryptor/Decryptor/Decryptor.cpp

#include "../TrustedInclude/Decryptor.h"
#include "sgx_tseal.h"
#include "sgx_tcrypto.h"
#include "sgx_dh.h"
#include "../TrustedInclude/error_codes.h"


        ECDSASignatureBox Decryptor::signatureBox;
        HybridEncryptionBox Decryptor::hybridEncryptionBoxClient;
        SymmetricEncryptionBox Decryptor::symmetricEncryptionBoxApache;
        SymmetricEncryptionBox Decryptor::symmetricEncryptionBoxVerifier;
        uint8_t Decryptor::verifier_mr_enclave[32] = {0};
        uint8_t Decryptor::apache_mr_signer[32] = {0};
        unsigned int successful_la_count;
        uint8_t Decryptor::plaintext_mitigator_header_H[ECDH_PUBLIC_KEY_SIZE + 32 + 64] = {0};
        uint8_t Decryptor::first_decryption_output[1092] = {0};
        uint8_t Decryptor::plaintext_client_data[1000] = {0};


  // INTERNAL
  uint32_t Decryptor::create_mitigator_token_M(uint8_t* token)
  {
    uint32_t internal_return_status;
    uint32_t counter;
    // create short-term ECDH key pair
    internal_return_status = hybridEncryptionBoxClient.generate_keypair();
    if(internal_return_status != 0)
      return internal_return_status;
    hybridEncryptionBoxClient.get_public_key(token);

    // create token: concatenate short-term keypair with verifiers mrenclave.
    for(counter=0;counter<32;counter++)
      *(token + counter + ECDH_PUBLIC_KEY_SIZE) = verifier_mr_enclave[counter];

    return 0;
  }

  // INTERNAL
  uint32_t Decryptor::create_mitigator_header_H(uint8_t* signature_data_and_signature)
  {
    uint32_t internal_return_status;
    uint8_t local_signature_data_and_signature[ECDH_PUBLIC_KEY_SIZE + 32 + 64];
    uint32_t counter;
    internal_return_status = Decryptor::create_mitigator_token_M(local_signature_data_and_signature);
    if(internal_return_status != 0x0)
      return internal_return_status;

    internal_return_status = signatureBox.sign(local_signature_data_and_signature, ECDH_PUBLIC_KEY_SIZE + 32, local_signature_data_and_signature + ECDH_PUBLIC_KEY_SIZE + 32);
    if(internal_return_status != 0x0)
      return internal_return_status;
    for(counter=0;counter<ECDH_PUBLIC_KEY_SIZE + 32 + 64;counter++)
      signature_data_and_signature[counter] = local_signature_data_and_signature[counter];
    return 0;
  }

  // EXTERNAL ECALL.
  uint32_t Decryptor::create_and_encrypt_mitigator_header_H(uint8_t* ciphertext_token_H_plus_tag, uint32_t* op_length)
  {
      uint32_t temp_ciphertext_token_H_iv_tag_length;
    	uint32_t internal_return_status;
        uint8_t plaintext_mitigator_header_H[ECDH_PUBLIC_KEY_SIZE + 32 + 64] = {0x42};

      if(successful_la_count != 2)
        return 0x33;

      internal_return_status = create_mitigator_header_H(plaintext_mitigator_header_H);
      if(internal_return_status != 0)
        return internal_return_status;

      internal_return_status = symmetricEncryptionBoxApache.encrypt_decrypt(1, plaintext_mitigator_header_H, ECDH_PUBLIC_KEY_SIZE + 32 + 64, ciphertext_token_H_plus_tag, &temp_ciphertext_token_H_iv_tag_length);
	*op_length = temp_ciphertext_token_H_iv_tag_length;
    	return internal_return_status;
    }

  // INTERNAL. done. But there might be one more return statement for the case when get_keypair returns sth (it is non void).
  uint32_t Decryptor::create_long_term_signing_keypair(uint8_t* private_public_key_string)
  {
    uint32_t internal_return_status;
    internal_return_status = signatureBox.generate_keypair();
    if(internal_return_status != 0)
      return internal_return_status;

    signatureBox.get_keypair(private_public_key_string);
    return 0;
  }

  // INTERNAL.
  uint32_t Decryptor::initialize_symmetric_key_decrypt_client_data(
          uint8_t* client_public_key_plus_ciphertext_fields, uint32_t* client_public_key_plus_ciphertext_fields_lengths,
          uint32_t number_of_ciphertext_fields,
          uint8_t* plaintext_fields, uint32_t* plaintext_field_lengths)
  {
    uint8_t *ciphertext_field_ptr, *plaintext_field_ptr;
    uint32_t plaintext_field_length, ciphertext_field_length, internal_return_status, counter;

    // I will derive a shared key from the plaintext_client_public_key
    internal_return_status = hybridEncryptionBoxClient.initialize_symmetric_key(client_public_key_plus_ciphertext_fields);
    if(internal_return_status != 0)
      return internal_return_status;

    // and then I will decrypt the rest of the client data with that key.
    ciphertext_field_ptr = client_public_key_plus_ciphertext_fields + client_public_key_plus_ciphertext_fields_lengths[0]; // tag = 16 bytes, iv = 12 bytes.
    plaintext_field_ptr = plaintext_fields;
    for(counter=0; counter<number_of_ciphertext_fields; counter++)
    {
        ciphertext_field_length = client_public_key_plus_ciphertext_fields_lengths[counter+1];
        internal_return_status = hybridEncryptionBoxClient.encrypt_decrypt(0, ciphertext_field_ptr,
              ciphertext_field_length, plaintext_field_ptr, &plaintext_field_length);
        if(internal_return_status != 0)
            return internal_return_status;
        plaintext_field_ptr += plaintext_field_length;
        ciphertext_field_ptr += ciphertext_field_length;

        plaintext_field_lengths[counter] = plaintext_field_length;
    }
    return internal_return_status;
  }

  void Decryptor::testing_long_term_verification_key(uint8_t* output)
  {
	uint8_t keypair[ECDH_PUBLIC_KEY_SIZE + ECDH_PRIVATE_KEY_SIZE];
	uint32_t counter;
	signatureBox.get_keypair(keypair);
	for(counter=0;counter<ECDH_PUBLIC_KEY_SIZE; counter++)
		output[counter]=keypair[ECDH_PRIVATE_KEY_SIZE+counter];
  }

  // EXTERNAL. DONE.
  uint32_t Decryptor::create_and_seal_long_term_signing_key_pair(size_t* sealed_data_length, uint8_t* sealed_data)
  {
        uint32_t sgx_libcall_status;
        uint32_t internal_return_status;
        uint32_t temp_sealed_data_length;
        uint8_t* temp_sealed_data;
        uint8_t private_public_key_string[ECDH_PUBLIC_KEY_SIZE + ECDH_PRIVATE_KEY_SIZE];
        uint32_t counter;

        temp_sealed_data_length = sgx_calc_sealed_data_size(0, ECDH_PUBLIC_KEY_SIZE + ECDH_PRIVATE_KEY_SIZE);
        if(temp_sealed_data_length == 0xFFFFFFFF)
          return 0x01;


        temp_sealed_data = (uint8_t*) malloc(temp_sealed_data_length);

        internal_return_status = create_long_term_signing_keypair(private_public_key_string);
      	if(internal_return_status != 0)
      	{
      		free(temp_sealed_data);
      		return internal_return_status;
      	}

        sgx_libcall_status = sgx_seal_data(0, NULL, 3*SGX_ECP256_KEY_SIZE, private_public_key_string, temp_sealed_data_length, (sgx_sealed_data_t*) temp_sealed_data);
        if(sgx_libcall_status != SGX_SUCCESS)
        {
          free(temp_sealed_data);
          return sgx_libcall_status;
        }

        for(counter=0;counter<temp_sealed_data_length;counter++)
    			*(sealed_data + counter)= *(temp_sealed_data + counter);
	      *sealed_data_length = temp_sealed_data_length;
        free(temp_sealed_data);

        return 0;
    }

  // EXTERNAL. DONE.
  uint32_t Decryptor::unseal_and_restore_long_term_signing_key_pair(uint8_t* sealed_data, size_t* sgx_sealed_data_length)
  {
      uint32_t temp_plaintext_length;
      uint8_t* temp_plaintext;
      uint32_t counter;
      uint32_t ret_status;
      uint8_t* temp_sealed_data ;

      temp_sealed_data = (uint8_t*) malloc(*sgx_sealed_data_length);
      for(counter=0;counter<*sgx_sealed_data_length;counter++)
        *(temp_sealed_data+counter)=*(sealed_data+counter);

      temp_plaintext_length = sgx_get_encrypt_txt_len((sgx_sealed_data_t*)sealed_data);
      if(temp_plaintext_length == 0xffffffff)
        return 0xFFFFFFFF;
      temp_plaintext = (uint8_t*)malloc( temp_plaintext_length );

      ret_status = sgx_unseal_data((sgx_sealed_data_t*)temp_sealed_data, NULL, 0, temp_plaintext, &temp_plaintext_length);
      free(temp_sealed_data);
      if(ret_status != SGX_SUCCESS)
      {
        free(temp_plaintext);
        return ret_status;
      }

      signatureBox.set_private_public_key(temp_plaintext, temp_plaintext + ECDH_PRIVATE_KEY_SIZE);
      free(temp_plaintext);
      return 0;
    }

  uint32_t Decryptor::process_verifiers_message(uint8_t* input_ciphertext_plus_tag, uint32_t length)
  {
        uint8_t first_decryption_output[150];
        uint32_t first_decryption_output_length;
        uint32_t  internal_return_status;
        uint32_t counter;
        if(successful_la_count != 1) // else, the untrusted application can call this on the first message by apache and cause the verifier to set its mrsigner.
          return 0x23;

        internal_return_status = symmetricEncryptionBoxVerifier.encrypt_decrypt(0, input_ciphertext_plus_tag, length, first_decryption_output, &first_decryption_output_length);
        if(internal_return_status != 0)
	  return internal_return_status;

        if(first_decryption_output_length != 32)
          return 0x33;

        for(counter=0; counter<32; counter++)
          apache_mr_signer[counter] = *(first_decryption_output + counter);


        return 0;
  }

  // INTERNAL.
    uint32_t Decryptor::encrypt_decrypt_to_apache(uint32_t encrypt_decrypt,
                                                    uint8_t* double_ciphertext,
                                                  uint32_t* double_ciphertext_fields_lengths,
                                                  uint32_t number_of_double_ciphertext_fields,
                                                  uint8_t* ciphertext,
                                                  uint32_t* ciphertext_length,
                                                  uint32_t* ciphertext_fields_lengths)
    {
        uint32_t ciphertext_field_length, field_counter, temp_total_ciphertext_length, internal_return_status;
        unsigned char *ciphertext_arr_ptr, *double_ciphertext_arr_ptr;

        double_ciphertext_arr_ptr = double_ciphertext;
        ciphertext_arr_ptr = ciphertext;

        // decrypt each set of bytes of length input_sizes_array[counter] of the input_ciphertext
        for(field_counter=0; field_counter<number_of_double_ciphertext_fields; field_counter++)
        {
            internal_return_status = symmetricEncryptionBoxApache.encrypt_decrypt(encrypt_decrypt, double_ciphertext_arr_ptr,
                                                                                  double_ciphertext_fields_lengths[field_counter],
                                                                                  ciphertext_arr_ptr, &ciphertext_field_length);
            if(internal_return_status != 0)
                return internal_return_status;

            double_ciphertext_arr_ptr += double_ciphertext_fields_lengths[field_counter];
            ciphertext_arr_ptr += ciphertext_field_length;
            ciphertext_fields_lengths[field_counter] = ciphertext_field_length;
            temp_total_ciphertext_length += ciphertext_field_length;
        }

        *ciphertext_length = temp_total_ciphertext_length;
        return 0;
    }

  uint32_t Decryptor::process_apache_message_generate_response(
            uint8_t* double_ciphertext,
            uint32_t double_ciphertext_length,
            uint32_t* double_ciphertext_fields_lengths,
            uint32_t number_of_double_ciphertext_fields,
            uint8_t* output_ciphertext,
            uint32_t* output_sizes_array)
{
      unsigned char *incoming_ciphertext, *plaintext;
      uint32_t *incoming_ciphertext_fields_lengths, *plaintext_fields_lengths;
      uint32_t internal_return_status, output_ciphertext_length, ciphertext_length;

      // UPPER BOUND - technically: double_ciphertext_length - (number_of_double_ciphertext_fields * 28)
      incoming_ciphertext = (unsigned char*) malloc(double_ciphertext_length);
      incoming_ciphertext_fields_lengths = (uint32_t*) malloc(number_of_double_ciphertext_fields);

      internal_return_status = encrypt_decrypt_to_apache(0,
              double_ciphertext,
              double_ciphertext_fields_lengths,
              number_of_double_ciphertext_fields,
              incoming_ciphertext,
              &ciphertext_length,
              incoming_ciphertext_fields_lengths);

      if(internal_return_status != 0)
      {
          free(incoming_ciphertext);
          free(incoming_ciphertext_fields_lengths);
          return internal_return_status;
      }

      plaintext = (unsigned char*) malloc(ciphertext_length);
      plaintext_fields_lengths = (uint32_t*) malloc(number_of_double_ciphertext_fields); // -1 technically.
      internal_return_status=initialize_symmetric_key_decrypt_client_data(
            incoming_ciphertext, incoming_ciphertext_fields_lengths,
            number_of_double_ciphertext_fields - 1,
            plaintext, plaintext_fields_lengths);
      free(incoming_ciphertext);
      free(incoming_ciphertext_fields_lengths);
      if(internal_return_status != 0)
      {
        free(plaintext);
        free(plaintext_fields_lengths);
        return internal_return_status;
      }

      internal_return_status = encrypt_decrypt_to_apache(1,
                                                       plaintext,
                                                       plaintext_fields_lengths,
                                                       number_of_double_ciphertext_fields-1,
                                                       output_ciphertext,
                                                       &output_ciphertext_length,
                                                       output_sizes_array);
      free(plaintext);
      free(plaintext_fields_lengths);
      return internal_return_status;
  }


    /*
    // EXTERNAL. DONE.
  uint32_t Decryptor::process_apache_message_generate_response(uint8_t* input_ciphertext, uint32_t input_ciphertext_plus_tag_length, uint8_t* output_ciphertext_plus_tag, uint32_t* output_ciphertext_plus_tag_length)
  {
      uint32_t first_decryption_output_length, plaintext_client_data_length;
      uint32_t internal_return_status;
      // TODO: May be have temporary variables for input ciphertext as they can't be passed directly to functions?
      // first, I decrypt the message from the target enclave, to get the client's public key and ciphertext data (and tag and IV)
      internal_return_status = symmetricEncryptionBoxApache.encrypt_decrypt(0, input_ciphertext, input_ciphertext_plus_tag_length,
              first_decryption_output, &first_decryption_output_length);
      if(internal_return_status != 0)
      	return internal_return_status;

	// then I obtain the plaintext client data, using the client's public key and own key to ultimately decrypt the client's ciphertext data
      internal_return_status = initialize_symmetric_key_decrypt_client_data(first_decryption_output, first_decryption_output_length, plaintext_client_data, &plaintext_client_data_length);
      if(internal_return_status != 0)
        return internal_return_status;

      // then I will encrypt the plaintext data to the target enclave.
      internal_return_status = symmetricEncryptionBoxApache.encrypt_decrypt(1, plaintext_client_data, plaintext_client_data_length, output_ciphertext_plus_tag, output_ciphertext_plus_tag_length);
	return internal_return_status;
    }
    */

  // INTERNAL.
  uint32_t Decryptor::verify_peer_enclave_trust(uint8_t* given_mr_enclave, uint8_t* given_mr_signer, uint8_t* dhaek)
  {
        uint32_t count;
        uint32_t internal_return_status;
        if(successful_la_count == 0) // verifier enclave
        {
                for(count=0; count<SGX_HASH_SIZE; count++)
                        verifier_mr_enclave[count] = given_mr_enclave[count];
		            symmetricEncryptionBoxVerifier.set_symmetric_key(dhaek);
        }
        else // apache enclave
        {
                for(count=0; count<SGX_HASH_SIZE; count++)
                {
                        if( given_mr_signer[count] != apache_mr_signer[count] )
                                return ENCLAVE_TRUST_ERROR;
                }
		            symmetricEncryptionBoxApache.set_symmetric_key(dhaek);
        }
        successful_la_count ++;
        return SGX_SUCCESS;
  }

  void Decryptor::calculate_sealed_keypair_size(size_t* output_length)
  {
	*output_length = sgx_calc_sealed_data_size(0, ECDH_PUBLIC_KEY_SIZE + ECDH_PRIVATE_KEY_SIZE);
}

    void Decryptor::testing_get_verifier_mrenclave_apache_mrsigner(uint8_t* output)
	{
		uint32_t counter;
		for(counter=0; counter<32;counter++)
		{
			output[counter]=verifier_mr_enclave[counter];
			output[counter+32]=apache_mr_signer[counter];
		}
	}
	void Decryptor::testing_get_short_term_public_key(uint8_t* output)
	{
		hybridEncryptionBoxClient.get_public_key(output);
	}


void Decryptor::testing_get_apache_iv(uint8_t* op)
{
	//	symmetricEncryptionBoxApache.get_iv(op);
}

uint32_t Decryptor::session_request(sgx_dh_msg1_t *dh_msg1, uint32_t *session_id)
{
    return LA::session_request(dh_msg1, session_id);
}

    uint32_t Decryptor::exchange_report(sgx_dh_msg2_t *dh_msg2, sgx_dh_msg3_t *dh_msg3, uint32_t *session_id)
    {
        sgx_key_128bit_t dh_aek;
        sgx_dh_session_enclave_identity_t initiator_identity;
        uint32_t la_ret_status = LA::exchange_report(dh_msg2, dh_msg3, session_id, &dh_aek, &initiator_identity);
      if(la_ret_status == 0)
      {
        return Decryptor::verify_peer_enclave_trust(initiator_identity.mr_enclave.m,
                initiator_identity.mr_signer.m,
                dh_aek);
      }
      else
          return la_ret_status;

    }