Diff: Devices/DS28C36_DS2476.cpp

Revision:

6:a8c83a2e6fa4

Parent:

3:f818ea5172ed

Child:

7:471901a04573

diff -r caf56f265a13 -r a8c83a2e6fa4 Devices/DS28C36_DS2476.cpp
--- a/Devices/DS28C36_DS2476.cpp	Fri Jan 19 10:25:02 2018 -0600
+++ b/Devices/DS28C36_DS2476.cpp	Wed Jan 23 13:11:04 2019 -0600
@@ -1,731 +1,709 @@
-/*******************************************************************************
-* Copyright (C) 2017 Maxim Integrated Products, Inc., All Rights Reserved.
-*
-* Permission is hereby granted, free of charge, to any person obtaining a
-* copy of this software and associated documentation files (the "Software"),
-* to deal in the Software without restriction, including without limitation
-* the rights to use, copy, modify, merge, publish, distribute, sublicense,
-* and/or sell copies of the Software, and to permit persons to whom the
-* Software is furnished to do so, subject to the following conditions:
-*
-* The above copyright notice and this permission notice shall be included
-* in all copies or substantial portions of the Software.
-*
-* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
-* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
-* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
-* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
-* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
-* OTHER DEALINGS IN THE SOFTWARE.
-*
-* Except as contained in this notice, the name of Maxim Integrated
-* Products, Inc. shall not be used except as stated in the Maxim Integrated
-* Products, Inc. Branding Policy.
-*
-* The mere transfer of this software does not imply any licenses
-* of trade secrets, proprietary technology, copyrights, patents,
-* trademarks, maskwork rights, or any other form of intellectual
-* property whatsoever. Maxim Integrated Products, Inc. retains all
-* ownership rights.
-*******************************************************************************/
-
-#include <MaximInterface/Links/I2CMaster.hpp>
-#include <MaximInterface/Utilities/Error.hpp>
-#include <MaximInterface/Utilities/RomId.hpp>
-#include "DS28C36_DS2476.hpp"
-
-using std::copy;
-
-namespace MaximInterface {
-using namespace Ecc256;
-
-// DS28C36 commands.
-enum Command {
-  WriteMemory = 0x96,
-  ReadMemory = 0x69,
-  WriteBuffer = 0x87,
-  ReadBuffer = 0x5A,
-  ReadPageProtection = 0xAA,
-  SetPageProtection = 0xC3,
-  DecrementCounter = 0xC9,
-  ReadRng = 0xD2,
-  EncryptedReadMemory = 0x4B,
-  ComputeAndReadPathAuthentication = 0xA5,
-  AuthenticatedSha2WriteMemory = 0x99,
-  ComputeAndLockSha2Secret = 0x3C,
-  GenerateEcc256KeyPair = 0xCB,
-  ComputeMultiblockHash = 0x33,
-  VerifyEcdsaSignature = 0x59,
-  AuthenticateEcdsaPublicKey = 0xA8,
-  AuthenticatedEcdsaWriteMemory = 0x89
-};
-
-static error_code convertResultByte(uint_least8_t resultByte) {
-  error_code errorCode;
-  if (resultByte != 0xAA) {
-    errorCode.assign((resultByte == 0x00)
-                         ? static_cast<int>(DS28C36::AuthenticationError)
-                         : resultByte,
-                     DS28C36::errorCategory());
-  }
-  return errorCode;
-}
-
-error_code DS28C36::writeMemory(int pageNum, const Page & page) {
-  if (pageNum < 0 || pageNum >= memoryPages) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  array<uint_least8_t, 1 + Page::csize> buffer;
-  buffer[0] = pageNum;
-  copy(page.begin(), page.end(), buffer.begin() + 1);
-  error_code result = writeCommand(WriteMemory, buffer.data(), buffer.size());
-  if (!result) {
-    sleep(writeMemoryTimeMs);
-    result = readFixedLengthResponse(buffer.data(), 1);
-    if (!result) {
-      result = convertResultByte(buffer[0]);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::readMemory(int pageNum, Page & page) {
-  if (pageNum < 0 || pageNum >= memoryPages) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  const uint_least8_t parameter = pageNum;
-  error_code result = writeCommand(ReadMemory, &parameter, 1);
-  if (!result) {
-    sleep(readMemoryTimeMs);
-    array<uint_least8_t, 1 + Page::csize> response;
-    result = readFixedLengthResponse(response.data(), response.size());
-    if (!result) {
-      result = convertResultByte(response[0]);
-      copy(response.begin() + 1, response.end(), page.begin());
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::writeBuffer(const uint_least8_t * data, size_t dataSize) {
-  return writeCommand(WriteBuffer, data, dataSize);
-}
-
-error_code DS28C36::readBuffer(std::vector<uint_least8_t> & data) {
-  error_code result = writeCommand(ReadBuffer);
-  if (!result) {
-    data.resize(80);
-    size_t dataSize = data.size();
-    result = readVariableLengthResponse(&data[0], dataSize);
-    if (result) {
-      data.clear();
-    } else {
-      data.resize(dataSize);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::readPageProtection(int pageNum,
-                                       PageProtection & protection) {
-  if (pageNum < 0 || pageNum >= memoryPages) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  uint_least8_t buffer = pageNum;
-  error_code result = writeCommand(ReadPageProtection, &buffer, 1);
-  if (!result) {
-    sleep(readMemoryTimeMs);
-    result = readFixedLengthResponse(&buffer, 1);
-    if (!result) {
-      protection = buffer;
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::setPageProtection(int pageNum,
-                                      const PageProtection & protection) {
-  if (pageNum < 0 || pageNum >= memoryPages) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  array<uint_least8_t, 2> buffer = {
-      static_cast<uint_least8_t>(pageNum),
-      static_cast<uint_least8_t>(protection.to_ulong())};
-  error_code result =
-      writeCommand(SetPageProtection, buffer.data(), buffer.size());
-  if (!result) {
-    sleep(writeMemoryTimeMs);
-    result = readFixedLengthResponse(buffer.data(), 1);
-    if (!result) {
-      result = convertResultByte(buffer[0]);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::decrementCounter() {
-  error_code result = writeCommand(DecrementCounter);
-  if (!result) {
-    sleep(writeMemoryTimeMs);
-    uint_least8_t response;
-    result = readFixedLengthResponse(&response, 1);
-    if (!result) {
-      result = convertResultByte(response);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::readRng(uint_least8_t * data, size_t dataSize) {
-  if ((dataSize < 1) || (dataSize > 64)) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  data[0] = static_cast<uint_least8_t>(dataSize - 1);
-  error_code result = writeCommand(ReadRng, data, 1);
-  if (!result) {
-    sleep(sha256ComputationTimeMs);
-    result = readFixedLengthResponse(data, dataSize);
-  }
-  return result;
-}
-
-error_code DS28C36::encryptedReadMemory(int pageNum, SecretNum secretNum,
-                                        EncryptedPage & page) {
-  if (pageNum < 0 || pageNum >= memoryPages) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  const uint_least8_t parameter = (secretNum << 6) | pageNum;
-  error_code result = writeCommand(EncryptedReadMemory, &parameter, 1);
-  if (!result) {
-    sleep(readMemoryTimeMs + sha256ComputationTimeMs);
-    typedef array<uint_least8_t, 1 + EncryptedPage::size> Response;
-    Response response;
-    result = readFixedLengthResponse(response.data(), response.size());
-    if (!result) {
-      result = convertResultByte(response[0]);
-      Response::const_iterator begin = response.begin() + 1;
-      Response::const_iterator end = begin + page.challenge.size();
-      copy(begin, end, page.challenge.begin());
-      begin = end;
-      end = begin + page.data.size();
-      copy(begin, end, page.data.begin());
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::computeAndReadPageAuthentication(int pageNum,
-                                                     AuthType authType) {
-  if (pageNum < 0 || pageNum >= memoryPages) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  const uint_least8_t parameter = (authType << 5) | pageNum;
-  return writeCommand(ComputeAndReadPathAuthentication, &parameter, 1);
-}
-
-error_code
-DS28C36::computeAndReadEcdsaPageAuthentication(int pageNum, KeyNum keyNum,
-                                               Signature & signature) {
-  AuthType authType;
-  switch (keyNum) {
-  case KeyNumA:
-    authType = EcdsaWithKeyA;
-    break;
-  case KeyNumB:
-    authType = EcdsaWithKeyB;
-    break;
-  case KeyNumC:
-    authType = EcdsaWithKeyC;
-    break;
-  default:
-    return make_error_code(InvalidParameterError);
-  }
-  error_code result = computeAndReadPageAuthentication(pageNum, authType);
-  if (!result) {
-    sleep(sha256ComputationTimeMs);
-    typedef array<uint_least8_t, 1 + Signature::size> Response;
-    Response response;
-    result = readFixedLengthResponse(response.data(), response.size());
-    if (!result) {
-      result = convertResultByte(response[0]);
-      Response::const_iterator begin = response.begin() + 1;
-      Response::const_iterator end = begin + signature.s.size();
-      copy(begin, end, signature.s.begin());
-      begin = end;
-      end = begin + signature.r.size();
-      copy(begin, end, signature.r.begin());
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::computeAndReadHmacPageAuthentication(int pageNum,
-                                                         SecretNum secretNum,
-                                                         Sha256::Hash & hmac) {
-  AuthType authType;
-  switch (secretNum) {
-  case SecretNumA:
-    authType = HmacWithSecretA;
-    break;
-  case SecretNumB:
-    authType = HmacWithSecretB;
-    break;
-  case SecretNumS:
-    authType = HmacWithSecretS;
-    break;
-  default:
-    return make_error_code(InvalidParameterError);
-  }
-  error_code result = computeAndReadPageAuthentication(pageNum, authType);
-  if (!result) {
-    sleep(generateEcdsaSignatureTimeMs);
-    array<uint_least8_t, 1 + Sha256::Hash::csize> response;
-    result = readFixedLengthResponse(response.data(), response.size());
-    if (!result) {
-      result = convertResultByte(response[0]);
-      copy(response.begin() + 1, response.end(), hmac.begin());
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::authenticatedSha2WriteMemory(int pageNum,
-                                                 SecretNum secretNum,
-                                                 const Page & page) {
-  if (pageNum < 0 || pageNum >= memoryPages) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  array<uint_least8_t, 1 + Page::csize> buffer;
-  buffer[0] = (secretNum << 6) | pageNum;
-  copy(page.begin(), page.end(), buffer.begin() + 1);
-  error_code result =
-      writeCommand(AuthenticatedSha2WriteMemory, buffer.data(), buffer.size());
-  if (!result) {
-    sleep(writeMemoryTimeMs + (2 * sha256ComputationTimeMs));
-    result = readFixedLengthResponse(buffer.data(), 1);
-    if (!result) {
-      result = convertResultByte(buffer[0]);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::computeAndLockSha2Secret(int pageNum, SecretNum msecretNum,
-                                             SecretNum dsecretNum,
-                                             bool writeProtectEnable) {
-  // User pages only
-  if (pageNum < UserData0 || pageNum > UserData15) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  array<uint_least8_t, 2> buffer = {
-      static_cast<uint_least8_t>((dsecretNum << 6) | (msecretNum << 4) |
-                                 pageNum),
-      static_cast<uint_least8_t>(writeProtectEnable ? 0x80 : 0x00)};
-  error_code result =
-      writeCommand(ComputeAndLockSha2Secret, buffer.data(), buffer.size());
-  if (!result) {
-    sleep(sha256ComputationTimeMs +
-          ((writeProtectEnable ? 2 : 1) * writeMemoryTimeMs));
-    result = readFixedLengthResponse(buffer.data(), 1);
-    if (!result) {
-      result = convertResultByte(buffer[0]);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::generateEcc256KeyPair(KeyNum keyNum,
-                                          bool writeProtectEnable) {
-  if (keyNum == KeyNumS) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  uint_least8_t buffer = keyNum;
-  if (writeProtectEnable) {
-    buffer |= 0x80;
-  }
-  error_code result = writeCommand(GenerateEcc256KeyPair, &buffer, 1);
-  if (!result) {
-    sleep(generateEccKeyPairTimeMs);
-    result = readFixedLengthResponse(&buffer, 1);
-    if (!result) {
-      result = convertResultByte(buffer);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::computeMultiblockHash(bool firstBlock, bool lastBlock,
-                                          const uint_least8_t * data,
-                                          size_t dataSize) {
-  const size_t maxDataSize = 64;
-
-  if (dataSize < 1 || dataSize > maxDataSize) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  array<uint_least8_t, 1 + maxDataSize> buffer;
-  buffer[0] = 0;
-  if (firstBlock) {
-    buffer[0] |= 0x40;
-  }
-  if (lastBlock) {
-    buffer[0] |= 0x80;
-  }
-  copy(data, data + dataSize, buffer.begin() + 1);
-  error_code result =
-      writeCommand(ComputeMultiblockHash, buffer.data(), dataSize + 1);
-  if (!result) {
-    sleep(sha256ComputationTimeMs);
-    result = readFixedLengthResponse(buffer.data(), 1);
-    if (!result) {
-      result = convertResultByte(buffer[0]);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::verifyEcdsaSignature(KeyNum keyNum, HashType hashType,
-                                         const Signature & signature,
-                                         PioState pioa, PioState piob) {
-  typedef array<uint_least8_t, 1 + Signature::size> Buffer;
-  Buffer buffer;
-  buffer[0] = keyNum | (hashType << 2);
-  if (pioa != Unchanged) {
-    buffer[0] |= 0x20;
-  }
-  if (pioa == Conducting) {
-    buffer[0] |= 0x10;
-  }
-  if (piob != Unchanged) {
-    buffer[0] |= 0x80;
-  }
-  if (piob == Conducting) {
-    buffer[0] |= 0x40;
-  }
-  Buffer::iterator bufferIt =
-      copy(signature.r.begin(), signature.r.end(), buffer.begin() + 1);
-  copy(signature.s.begin(), signature.s.end(), bufferIt);
-  error_code result =
-      writeCommand(VerifyEcdsaSignature, buffer.data(), buffer.size());
-  if (!result) {
-    sleep(verifyEsdsaSignatureOrComputeEcdhTimeMs +
-          ((hashType == DataInBuffer) ? sha256ComputationTimeMs : 0));
-    result = readFixedLengthResponse(buffer.data(), 1);
-    if (!result) {
-      result = convertResultByte(buffer[0]);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::authenticateEcdsaPublicKey(bool authWrites, bool ecdh,
-                                               KeyNum keyNum, int csOffset,
-                                               const Signature & signature) {
-  if (((keyNum != KeyNumA) && (keyNum != KeyNumB)) || (csOffset < 0) ||
-      (csOffset > 31)) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  typedef array<uint_least8_t, 1 + Signature::size> Buffer;
-  Buffer buffer;
-  buffer[0] = (csOffset << 3) | (keyNum << 2);
-  if (ecdh) {
-    buffer[0] |= 0x02;
-  }
-  if (authWrites) {
-    buffer[0] |= 0x01;
-  }
-  Buffer::iterator bufferIt =
-      copy(signature.r.begin(), signature.r.end(), buffer.begin() + 1);
-  copy(signature.s.begin(), signature.s.end(), bufferIt);
-  error_code result =
-      writeCommand(AuthenticateEcdsaPublicKey, buffer.data(), buffer.size());
-  if (!result) {
-    sleep((ecdh ? 2 : 1) * verifyEsdsaSignatureOrComputeEcdhTimeMs);
-    result = readFixedLengthResponse(buffer.data(), 1);
-    if (!result) {
-      result = convertResultByte(buffer[0]);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::authenticatedEcdsaWriteMemory(int pageNum,
-                                                  const Page & page) {
-  if (pageNum < 0 || pageNum >= memoryPages) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  array<uint_least8_t, 1 + Page::csize> buffer;
-  buffer[0] = pageNum;
-  copy(page.begin(), page.end(), buffer.begin() + 1);
-  error_code result =
-      writeCommand(AuthenticatedEcdsaWriteMemory, buffer.data(), buffer.size());
-  if (!result) {
-    sleep(verifyEsdsaSignatureOrComputeEcdhTimeMs + writeMemoryTimeMs +
-          sha256ComputationTimeMs);
-    result = readFixedLengthResponse(buffer.data(), 1);
-    if (!result) {
-      result = convertResultByte(buffer[0]);
-    }
-  }
-  return result;
-}
-
-error_code DS28C36::writeCommand(uint_least8_t command,
-                                 const uint_least8_t * parameters,
-                                 size_t parametersSize) {
-  error_code result = master->start(address_);
-  if (result) {
-    master->stop();
-    return result;
-  }
-  result = master->writeByte(command);
-  if (result) {
-    master->stop();
-    return result;
-  }
-  if (parameters) {
-    result = master->writeByte(static_cast<uint_least8_t>(parametersSize));
-    if (result) {
-      master->stop();
-      return result;
-    }
-    result = master->writeBlock(parameters, parametersSize);
-    if (result) {
-      master->stop();
-      return result;
-    }
-  }
-  result = master->stop();
-  return result;
-}
-
-error_code DS28C36::readVariableLengthResponse(uint_least8_t * response,
-                                               size_t & responseSize) {
-  error_code result = master->start(address_ | 1);
-  if (result) {
-    master->stop();
-    return result;
-  }
-  uint_least8_t length;
-  result = master->readByte(I2CMaster::Ack, length);
-  if (result) {
-    master->stop();
-    return result;
-  }
-  if (length > responseSize) {
-    master->stop();
-    return make_error_code(InvalidResponseError);
-  }
-  if (length > 0) {
-    result = master->readBlock(I2CMaster::Nack, response, length);
-    if (result) {
-      master->stop();
-      return result;
-    }
-  }
-  responseSize = length;
-  result = master->stop();
-  return result;
-}
-
-error_code DS28C36::readFixedLengthResponse(uint_least8_t * response,
-                                            size_t responseSize) {
-  const size_t requestedResponseSize = responseSize;
-  error_code result = readVariableLengthResponse(response, responseSize);
-  if (!result && responseSize != requestedResponseSize) {
-    result = make_error_code(InvalidResponseError);
-  }
-  return result;
-}
-
-DS28C36::PageAuthenticationData
-DS28C36::createPageAuthenticationData(const RomId & romId, const Page & page,
-                                      const Page & challenge, int pageNum,
-                                      const ManId & manId) {
-  PageAuthenticationData data;
-  PageAuthenticationData::iterator dataIt = data.begin();
-  dataIt = copy(romId.begin(), romId.end(), dataIt);
-  dataIt = copy(page.begin(), page.end(), dataIt);
-  dataIt = copy(challenge.begin(), challenge.end(), dataIt);
-  *dataIt = static_cast<uint_least8_t>(pageNum);
-  ++dataIt;
-  copy(manId.begin(), manId.end(), dataIt);
-  return data;
-}
-
-const error_category & DS28C36::errorCategory() {
-  static class : public error_category {
-  public:
-    virtual const char * name() const { return "DS28C36"; }
-
-    virtual std::string message(int condition) const {
-      switch (condition) {
-      case ProtectionError:
-        return "Protection Error";
-
-      case InvalidParameterError:
-        return "Invalid Parameter Error";
-
-      case InvalidSequenceError:
-        return "Invalid Sequence Error";
-
-      case InvalidEcdsaInputOrResultError:
-        return "Invalid ECDSA Input or Result Error";
-
-      case AuthenticationError:
-        return "Authentication Error";
-
-      case InvalidResponseError:
-        return "Invalid Response Error";
-
-      default:
-        return defaultErrorMessage(condition);
-      }
-    }
-  } instance;
-  return instance;
-}
-
-error_code readRomIdAndManId(DS28C36 & ds28c36, RomId * romId, ManId * manId) {
-  DS28C36::Page page;
-  const error_code result = ds28c36.readMemory(DS28C36::RomOptions, page);
-  if (!result) {
-    DS28C36::Page::const_iterator pageIt = page.begin() + 22;
-    if (manId) {
-      copy(pageIt, pageIt + ManId::size(), manId->begin());
-    }
-    pageIt += ManId::size();
-    if (romId) {
-      copy(pageIt, pageIt + RomId::size(), romId->begin());
-    }
-  }
-  return result;
-}
-
-error_code computeMultiblockHash(DS28C36 & ds28c36, const uint_least8_t * data,
-                                 const size_t dataSize) {
-  error_code result;
-  size_t remainingSize = dataSize;
-  while ((remainingSize > 0) && !result) {
-    const size_t chunkSize = std::min<size_t>(remainingSize, 64);
-    result = ds28c36.computeMultiblockHash(
-        remainingSize == dataSize, remainingSize == chunkSize, data, chunkSize);
-    data += chunkSize;
-    remainingSize -= chunkSize;
-  }
-  return result;
-}
-
-error_code verifyEcdsaSignature(DS28C36 & ds28c36, DS28C36::KeyNum publicKey,
-                                const uint_least8_t * data, size_t dataSize,
-                                const Signature & signature,
-                                DS28C36::PioState pioa,
-                                DS28C36::PioState piob) {
-  error_code result = computeMultiblockHash(ds28c36, data, dataSize);
-  if (!result) {
-    result = ds28c36.verifyEcdsaSignature(publicKey, DS28C36::THASH, signature,
-                                          pioa, piob);
-  }
-  return result;
-}
-
-error_code verifyEcdsaSignature(DS28C36 & ds28c36, const PublicKey & publicKey,
-                                const uint_least8_t * data, size_t dataSize,
-                                const Signature & signature,
-                                DS28C36::PioState pioa,
-                                DS28C36::PioState piob) {
-  error_code result = ds28c36.writeMemory(DS28C36::PublicKeySX, publicKey.x);
-  if (!result) {
-    result = ds28c36.writeMemory(DS28C36::PublicKeySY, publicKey.y);
-  }
-  if (!result) {
-    result = verifyEcdsaSignature(ds28c36, DS28C36::KeyNumS, data, dataSize,
-                                  signature, pioa, piob);
-  }
-  return result;
-}
-
-// DS2476 additional commands.
-enum DS2476_Command {
-  GenerateEcdsaSignature = 0x1E,
-  ComputeSha2UniqueSecret = 0x55,
-  ComputeSha2Hmac = 0x2D
-};
-
-error_code DS2476::generateEcdsaSignature(KeyNum keyNum,
-                                          Signature & signature) {
-  if (keyNum == KeyNumS) {
-    return make_error_code(InvalidParameterError);
-  }
-
-  const uint_least8_t parameter = keyNum;
-  error_code result = writeCommand(GenerateEcdsaSignature, &parameter, 1);
-  if (!result) {
-    sleep(generateEcdsaSignatureTimeMs);
-    typedef array<uint_least8_t, 1 + Signature::size> Response;
-    Response response;
-    result = readFixedLengthResponse(response.data(), response.size());
-    if (!result) {
-      result = convertResultByte(response[0]);
-      Response::const_iterator begin = response.begin() + 1;
-      Response::const_iterator end = begin + signature.s.size();
-      copy(begin, end, signature.s.begin());
-      begin = end;
-      end = begin + signature.r.size();
-      copy(begin, end, signature.r.begin());
-    }
-  }
-  return result;
-}
-
-error_code DS2476::computeSha2UniqueSecret(SecretNum msecretNum) {
-  uint_least8_t buffer = msecretNum << 4;
-  error_code result = writeCommand(ComputeSha2UniqueSecret, &buffer, 1);
-  if (!result) {
-    sleep(sha256ComputationTimeMs);
-    result = readFixedLengthResponse(&buffer, 1);
-    if (!result) {
-      convertResultByte(buffer);
-    }
-  }
-  return result;
-}
-
-error_code DS2476::computeSha2Hmac(Sha256::Hash & hmac) {
-  error_code result = writeCommand(ComputeSha2Hmac);
-  if (!result) {
-    sleep(sha256ComputationTimeMs);
-    array<uint_least8_t, 1 + Sha256::Hash::csize> response;
-    result = readFixedLengthResponse(response.data(), response.size());
-    if (!result) {
-      result = convertResultByte(response[0]);
-      copy(response.begin() + 1, response.end(), hmac.begin());
-    }
-  }
-  return result;
-}
-
-error_code enableCoprocessor(DS2476 & ds2476) {
-  DS2476::Page gpioControl;
-  error_code result = ds2476.readMemory(DS2476::GpioControl, gpioControl);
-  if (!result && gpioControl[0] != 0xAA) {
-    gpioControl[0] = 0xAA;
-    result = ds2476.writeMemory(DS2476::GpioControl, gpioControl);
-  }
-  return result;
-}
-
-} // namespace MaximInterface
+/*******************************************************************************
+* Copyright (C) 2017 Maxim Integrated Products, Inc., All Rights Reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a
+* copy of this software and associated documentation files (the "Software"),
+* to deal in the Software without restriction, including without limitation
+* the rights to use, copy, modify, merge, publish, distribute, sublicense,
+* and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included
+* in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
+* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+* OTHER DEALINGS IN THE SOFTWARE.
+*
+* Except as contained in this notice, the name of Maxim Integrated
+* Products, Inc. shall not be used except as stated in the Maxim Integrated
+* Products, Inc. Branding Policy.
+*
+* The mere transfer of this software does not imply any licenses
+* of trade secrets, proprietary technology, copyrights, patents,
+* trademarks, maskwork rights, or any other form of intellectual
+* property whatsoever. Maxim Integrated Products, Inc. retains all
+* ownership rights.
+*******************************************************************************/
+
+#include <algorithm>
+#include <MaximInterface/Links/I2CMaster.hpp>
+#include <MaximInterface/Utilities/Error.hpp>
+#include <MaximInterface/Utilities/RomId.hpp>
+#include "DS28C36_DS2476.hpp"
+
+namespace MaximInterface {
+
+using namespace Ecc256;
+using std::copy;
+
+static error_code convertResultByte(uint_least8_t resultByte) {
+  error_code errorCode;
+  if (resultByte != 0xAA) {
+    errorCode.assign((resultByte == 0x00)
+                         ? static_cast<int>(DS28C36::AuthenticationError)
+                         : resultByte,
+                     DS28C36::errorCategory());
+  }
+  return errorCode;
+}
+
+const int DS28C36::publicKeyAxPage;
+const int DS28C36::publicKeyAyPage;
+const int DS28C36::publicKeyBxPage;
+const int DS28C36::publicKeyByPage;
+const int DS28C36::publicKeyCxPage;
+const int DS28C36::publicKeyCyPage;
+const int DS28C36::privateKeyAPage;
+const int DS28C36::privateKeyBPage;
+const int DS28C36::privateKeyCPage;
+const int DS28C36::secretAPage;
+const int DS28C36::secretBPage;
+const int DS28C36::decrementCounterPage;
+const int DS28C36::romOptionsPage;
+const int DS28C36::gpioControlPage;
+const int DS28C36::publicKeySxPage;
+const int DS28C36::publicKeySyPage;
+const int DS28C36::memoryPages;
+
+error_code DS28C36::writeMemory(int pageNum, Page::const_span page) {
+  if (pageNum < 0 || pageNum >= memoryPages) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  uint_least8_t buffer[1 + Page::size];
+  buffer[0] = pageNum;
+  copy(page.begin(), page.end(), buffer + 1);
+  error_code result = writeCommand(0x96, buffer);
+  if (!result) {
+    sleep(writeMemoryTimeMs);
+    result = readFixedLengthResponse(make_span(buffer, 1));
+    if (!result) {
+      result = convertResultByte(buffer[0]);
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::readMemory(int pageNum, Page::span page) {
+  if (pageNum < 0 || pageNum >= memoryPages) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  const uint_least8_t parameter = pageNum;
+  error_code result = writeCommand(0x69, make_span(&parameter, 1));
+  if (!result) {
+    sleep(readMemoryTimeMs);
+    array<uint_least8_t, 1 + Page::size> response;
+    result = readFixedLengthResponse(response);
+    if (!result) {
+      result = convertResultByte(response[0]);
+      copy(response.begin() + 1, response.end(), page.begin());
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::writeBuffer(span<const uint_least8_t> data) {
+  return writeCommand(0x87, data);
+}
+
+error_code DS28C36::readBuffer(std::vector<uint_least8_t> & data) {
+  error_code result = writeCommand(0x5A);
+  if (!result) {
+    data.resize(80);
+    span<uint_least8_t> dataSpan(data);
+    result = readVariableLengthResponse(dataSpan);
+    if (result) {
+      data.clear();
+    } else {
+      data.resize(dataSpan.size());
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::readPageProtection(int pageNum,
+                                       PageProtection & protection) {
+  if (pageNum < 0 || pageNum >= memoryPages) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  uint_least8_t buffer = pageNum;
+  error_code result = writeCommand(0xAA, make_span(&buffer, 1));
+  if (!result) {
+    sleep(readMemoryTimeMs);
+    result = readFixedLengthResponse(make_span(&buffer, 1));
+    if (!result) {
+      protection = buffer;
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::setPageProtection(int pageNum,
+                                      const PageProtection & protection) {
+  if (pageNum < 0 || pageNum >= memoryPages) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  uint_least8_t buffer[] = {static_cast<uint_least8_t>(pageNum),
+                            static_cast<uint_least8_t>(protection.to_ulong())};
+  error_code result = writeCommand(0xC3, buffer);
+  if (!result) {
+    sleep(writeMemoryTimeMs);
+    result = readFixedLengthResponse(make_span(buffer, 1));
+    if (!result) {
+      result = convertResultByte(buffer[0]);
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::decrementCounter() {
+  error_code result = writeCommand(0xC9);
+  if (!result) {
+    sleep(writeMemoryTimeMs);
+    uint_least8_t response;
+    result = readFixedLengthResponse(make_span(&response, 1));
+    if (!result) {
+      result = convertResultByte(response);
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::readRng(span<uint_least8_t> data) {
+  if ((data.size() < 1) || (data.size() > 64)) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  data[0] = static_cast<uint_least8_t>(data.size() - 1);
+  error_code result = writeCommand(0xD2, data.first(1));
+  if (!result) {
+    sleep(sha256ComputationTimeMs);
+    result = readFixedLengthResponse(data);
+  }
+  return result;
+}
+
+error_code DS28C36::encryptedReadMemory(int pageNum, SecretNum secretNum,
+                                        EncryptionChallenge::span challenge,
+                                        Page::span data) {
+  if (pageNum < 0 || pageNum >= memoryPages) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  const uint_least8_t parameter = (secretNum << 6) | pageNum;
+  error_code result = writeCommand(0x4B, make_span(&parameter, 1));
+  if (!result) {
+    sleep(readMemoryTimeMs + sha256ComputationTimeMs);
+    uint_least8_t response[1 + EncryptionChallenge::size + Page::size];
+    result = readFixedLengthResponse(response);
+    if (!result) {
+      result = convertResultByte(response[0]);
+      const uint_least8_t * begin = response + 1;
+      const uint_least8_t * end = begin + challenge.size();
+      copy(begin, end, challenge.begin());
+      begin = end;
+      end = begin + data.size();
+      copy(begin, end, data.begin());
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::computeAndReadPageAuthentication(int pageNum,
+                                                     AuthType authType) {
+  if (pageNum < 0 || pageNum >= memoryPages) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  const uint_least8_t parameter = (authType << 5) | pageNum;
+  return writeCommand(0xA5, make_span(&parameter, 1));
+}
+
+error_code
+DS28C36::computeAndReadPageAuthentication(int pageNum, KeyNum keyNum,
+                                          Signature::span signature) {
+  AuthType authType;
+  switch (keyNum) {
+  case KeyNumA:
+    authType = EcdsaWithKeyA;
+    break;
+  case KeyNumB:
+    authType = EcdsaWithKeyB;
+    break;
+  case KeyNumC:
+    authType = EcdsaWithKeyC;
+    break;
+  default:
+    return make_error_code(InvalidParameterError);
+  }
+  error_code result = computeAndReadPageAuthentication(pageNum, authType);
+  if (!result) {
+    sleep(readMemoryTimeMs + generateEcdsaSignatureTimeMs);
+    uint_least8_t response[1 + 2 * Scalar::size];
+    result = readFixedLengthResponse(response);
+    if (!result) {
+      result = convertResultByte(response[0]);
+      const uint_least8_t * begin = response + 1;
+      const uint_least8_t * end = begin + signature.s.size();
+      copy(begin, end, signature.s.begin());
+      begin = end;
+      end = begin + signature.r.size();
+      copy(begin, end, signature.r.begin());
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::computeAndReadPageAuthentication(int pageNum,
+                                                     SecretNum secretNum,
+                                                     Sha256::Hash::span hmac) {
+  AuthType authType;
+  switch (secretNum) {
+  case SecretNumA:
+    authType = HmacWithSecretA;
+    break;
+  case SecretNumB:
+    authType = HmacWithSecretB;
+    break;
+  case SecretNumS:
+    authType = HmacWithSecretS;
+    break;
+  default:
+    return make_error_code(InvalidParameterError);
+  }
+  error_code result = computeAndReadPageAuthentication(pageNum, authType);
+  if (!result) {
+    sleep(readMemoryTimeMs + sha256ComputationTimeMs);
+    array<uint_least8_t, 1 + Sha256::Hash::size> response;
+    result = readFixedLengthResponse(response);
+    if (!result) {
+      result = convertResultByte(response[0]);
+      copy(response.begin() + 1, response.end(), hmac.begin());
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::authenticatedSha2WriteMemory(int pageNum,
+                                                 SecretNum secretNum,
+                                                 Page::const_span page) {
+  if (pageNum < 0 || pageNum >= memoryPages) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  uint_least8_t buffer[1 + Page::size];
+  buffer[0] = (secretNum << 6) | pageNum;
+  copy(page.begin(), page.end(), buffer + 1);
+  error_code result = writeCommand(0x99, buffer);
+  if (!result) {
+    sleep(writeMemoryTimeMs + (2 * sha256ComputationTimeMs));
+    result = readFixedLengthResponse(make_span(buffer, 1));
+    if (!result) {
+      result = convertResultByte(buffer[0]);
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::computeAndLockSha2Secret(int pageNum, SecretNum msecretNum,
+                                             SecretNum dsecretNum,
+                                             bool writeProtectEnable) {
+  // User pages only
+  if (pageNum < 0 || pageNum > 15) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  uint_least8_t buffer[] = {
+      static_cast<uint_least8_t>((dsecretNum << 6) | (msecretNum << 4) |
+                                 pageNum),
+      static_cast<uint_least8_t>(writeProtectEnable ? 0x80 : 0x00)};
+  error_code result = writeCommand(0x3C, buffer);
+  if (!result) {
+    sleep(sha256ComputationTimeMs +
+          ((writeProtectEnable ? 2 : 1) * writeMemoryTimeMs));
+    result = readFixedLengthResponse(make_span(buffer, 1));
+    if (!result) {
+      result = convertResultByte(buffer[0]);
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::generateEcc256KeyPair(KeyNum keyNum,
+                                          bool writeProtectEnable) {
+  if (keyNum == KeyNumS) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  uint_least8_t buffer = keyNum;
+  if (writeProtectEnable) {
+    buffer |= 0x80;
+  }
+  error_code result = writeCommand(0xCB, make_span(&buffer, 1));
+  if (!result) {
+    sleep(generateEccKeyPairTimeMs);
+    result = readFixedLengthResponse(make_span(&buffer, 1));
+    if (!result) {
+      result = convertResultByte(buffer);
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::computeMultiblockHash(bool firstBlock, bool lastBlock,
+                                          span<const uint_least8_t> data) {
+  const span<const uint_least8_t>::index_type maxDataSize = 64;
+
+  if (data.size() < 1 || data.size() > maxDataSize) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  uint_least8_t buffer[1 + maxDataSize];
+  buffer[0] = 0;
+  if (firstBlock) {
+    buffer[0] |= 0x40;
+  }
+  if (lastBlock) {
+    buffer[0] |= 0x80;
+  }
+  copy(data.begin(), data.end(), buffer + 1);
+  error_code result = writeCommand(0x33, make_span(buffer, data.size() + 1));
+  if (!result) {
+    sleep(sha256ComputationTimeMs);
+    result = readFixedLengthResponse(make_span(buffer, 1));
+    if (!result) {
+      result = convertResultByte(buffer[0]);
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::verifyEcdsaSignature(KeyNum keyNum, HashType hashType,
+                                         Signature::const_span signature,
+                                         PioState pioa, PioState piob) {
+  uint_least8_t buffer[1 + 2 * Scalar::size];
+  buffer[0] = keyNum | (hashType << 2);
+  if (pioa != Unchanged) {
+    buffer[0] |= 0x20;
+  }
+  if (pioa == Conducting) {
+    buffer[0] |= 0x10;
+  }
+  if (piob != Unchanged) {
+    buffer[0] |= 0x80;
+  }
+  if (piob == Conducting) {
+    buffer[0] |= 0x40;
+  }
+  uint_least8_t * bufferIt =
+      copy(signature.r.begin(), signature.r.end(), buffer + 1);
+  copy(signature.s.begin(), signature.s.end(), bufferIt);
+  error_code result = writeCommand(0x59, buffer);
+  if (!result) {
+    sleep(verifyEsdsaSignatureOrComputeEcdhTimeMs +
+          ((hashType == DataInBuffer) ? sha256ComputationTimeMs : 0));
+    result = readFixedLengthResponse(make_span(buffer, 1));
+    if (!result) {
+      result = convertResultByte(buffer[0]);
+    }
+  }
+  return result;
+}
+
+error_code
+DS28C36::authenticateEcdsaPublicKey(bool authWrites, bool ecdh, KeyNum keyNum,
+                                    int csOffset,
+                                    Signature::const_span signature) {
+  if (((keyNum != KeyNumA) && (keyNum != KeyNumB)) || (csOffset < 0) ||
+      (csOffset > 31)) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  uint_least8_t buffer[1 + 2 * Scalar::size];
+  buffer[0] = (csOffset << 3) | (keyNum << 2);
+  if (ecdh) {
+    buffer[0] |= 0x02;
+  }
+  if (authWrites) {
+    buffer[0] |= 0x01;
+  }
+  uint_least8_t * bufferIt =
+      copy(signature.r.begin(), signature.r.end(), buffer + 1);
+  copy(signature.s.begin(), signature.s.end(), bufferIt);
+  error_code result = writeCommand(0xA8, buffer);
+  if (!result) {
+    sleep((ecdh ? 2 : 1) * verifyEsdsaSignatureOrComputeEcdhTimeMs);
+    result = readFixedLengthResponse(make_span(buffer, 1));
+    if (!result) {
+      result = convertResultByte(buffer[0]);
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::authenticatedEcdsaWriteMemory(int pageNum,
+                                                  Page::const_span page) {
+  if (pageNum < 0 || pageNum >= memoryPages) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  uint_least8_t buffer[1 + Page::size];
+  buffer[0] = pageNum;
+  copy(page.begin(), page.end(), buffer + 1);
+  error_code result = writeCommand(0x89, buffer);
+  if (!result) {
+    sleep(verifyEsdsaSignatureOrComputeEcdhTimeMs + writeMemoryTimeMs +
+          sha256ComputationTimeMs);
+    result = readFixedLengthResponse(make_span(buffer, 1));
+    if (!result) {
+      result = convertResultByte(buffer[0]);
+    }
+  }
+  return result;
+}
+
+error_code DS28C36::writeCommand(uint_least8_t command,
+                                 span<const uint_least8_t> parameters) {
+  error_code result = master->start(address_);
+  if (result) {
+    master->stop();
+    return result;
+  }
+  result = master->writeByte(command);
+  if (result) {
+    master->stop();
+    return result;
+  }
+  if (!parameters.empty()) {
+    result = master->writeByte(static_cast<uint_least8_t>(parameters.size()));
+    if (result) {
+      master->stop();
+      return result;
+    }
+    result = master->writeBlock(parameters);
+    if (result) {
+      master->stop();
+      return result;
+    }
+  }
+  result = master->stop();
+  return result;
+}
+
+error_code DS28C36::readVariableLengthResponse(span<uint_least8_t> & response) {
+  error_code result = master->start(address_ | 1);
+  if (result) {
+    master->stop();
+    return result;
+  }
+  uint_least8_t length;
+  result = master->readByte(I2CMaster::Ack, length);
+  if (result) {
+    master->stop();
+    return result;
+  }
+  if (length > response.size()) {
+    master->stop();
+    return make_error_code(InvalidResponseError);
+  }
+  response = response.first(length);
+  if (!response.empty()) {
+    result = master->readBlock(I2CMaster::Nack, response);
+    if (result) {
+      master->stop();
+      return result;
+    }
+  }
+  result = master->stop();
+  return result;
+}
+
+error_code DS28C36::readFixedLengthResponse(span<uint_least8_t> response) {
+  const span<uint_least8_t>::index_type requestedResponseSize = response.size();
+  error_code result = readVariableLengthResponse(response);
+  if (!result && response.size() != requestedResponseSize) {
+    result = make_error_code(InvalidResponseError);
+  }
+  return result;
+}
+
+const error_category & DS28C36::errorCategory() {
+  static class : public error_category {
+  public:
+    virtual const char * name() const { return "DS28C36"; }
+
+    virtual std::string message(int condition) const {
+      switch (condition) {
+      case ProtectionError:
+        return "Protection Error";
+
+      case InvalidParameterError:
+        return "Invalid Parameter Error";
+
+      case InvalidSequenceError:
+        return "Invalid Sequence Error";
+
+      case InvalidEcdsaInputOrResultError:
+        return "Invalid ECDSA Input or Result Error";
+
+      case AuthenticationError:
+        return "Authentication Error";
+
+      case InvalidResponseError:
+        return "Invalid Response Error";
+
+      default:
+        return defaultErrorMessage(condition);
+      }
+    }
+  } instance;
+  return instance;
+}
+
+error_code DS2476::generateEcdsaSignature(KeyNum keyNum,
+                                          Signature::span signature) {
+  if (keyNum == KeyNumS) {
+    return make_error_code(InvalidParameterError);
+  }
+
+  const uint_least8_t parameter = keyNum;
+  error_code result = writeCommand(0x1E, make_span(&parameter, 1));
+  if (!result) {
+    sleep(generateEcdsaSignatureTimeMs);
+    uint_least8_t response[1 + 2 * Scalar::size];
+    result = readFixedLengthResponse(response);
+    if (!result) {
+      result = convertResultByte(response[0]);
+      const uint_least8_t * begin = response + 1;
+      const uint_least8_t * end = begin + signature.s.size();
+      copy(begin, end, signature.s.begin());
+      begin = end;
+      end = begin + signature.r.size();
+      copy(begin, end, signature.r.begin());
+    }
+  }
+  return result;
+}
+
+error_code DS2476::computeSha2UniqueSecret(SecretNum msecretNum) {
+  uint_least8_t buffer = msecretNum << 4;
+  error_code result = writeCommand(0x55, make_span(&buffer, 1));
+  if (!result) {
+    sleep(sha256ComputationTimeMs);
+    result = readFixedLengthResponse(make_span(&buffer, 1));
+    if (!result) {
+      convertResultByte(buffer);
+    }
+  }
+  return result;
+}
+
+error_code DS2476::computeSha2Hmac(Sha256::Hash::span hmac) {
+  error_code result = writeCommand(0x2D);
+  if (!result) {
+    sleep(sha256ComputationTimeMs);
+    array<uint_least8_t, 1 + Sha256::Hash::size> response;
+    result = readFixedLengthResponse(response);
+    if (!result) {
+      result = convertResultByte(response[0]);
+      copy(response.begin() + 1, response.end(), hmac.begin());
+    }
+  }
+  return result;
+}
+
+error_code computeMultiblockHash(DS28C36 & ds28c36,
+                                 span<const uint_least8_t> data) {
+  error_code result;
+  span<const uint_least8_t>::index_type dataIdx = 0;
+  while (dataIdx < data.size() && !result) {
+    const span<const uint_least8_t>::index_type remainingSize =
+        data.size() - dataIdx;
+    const span<const uint_least8_t>::index_type chunkSize =
+        std::min<span<const uint_least8_t>::index_type>(remainingSize, 64);
+    result =
+        ds28c36.computeMultiblockHash(dataIdx == 0, remainingSize == chunkSize,
+                                      data.subspan(dataIdx, chunkSize));
+    dataIdx += chunkSize;
+  }
+  return result;
+}
+
+error_code verifyEcdsaSignature(DS28C36 & ds28c36, DS28C36::KeyNum publicKey,
+                                span<const uint_least8_t> data,
+                                Signature::const_span signature,
+                                DS28C36::PioState pioa,
+                                DS28C36::PioState piob) {
+  error_code result = computeMultiblockHash(ds28c36, data);
+  if (!result) {
+    result = ds28c36.verifyEcdsaSignature(publicKey, DS28C36::THASH, signature,
+                                          pioa, piob);
+  }
+  return result;
+}
+
+error_code verifyEcdsaSignature(DS28C36 & ds28c36,
+                                PublicKey::const_span publicKey,
+                                span<const uint_least8_t> data,
+                                Signature::const_span signature,
+                                DS28C36::PioState pioa,
+                                DS28C36::PioState piob) {
+  error_code result =
+      ds28c36.writeMemory(DS28C36::publicKeySxPage, publicKey.x);
+  if (!result) {
+    result = ds28c36.writeMemory(DS28C36::publicKeySyPage, publicKey.y);
+  }
+  if (!result) {
+    result = verifyEcdsaSignature(ds28c36, DS28C36::KeyNumS, data, signature,
+                                  pioa, piob);
+  }
+  return result;
+}
+
+error_code readRomIdAndManId(DS28C36 & ds28c36, RomId::span romId,
+                             ManId::span manId) {
+  DS28C36::RomOptions romOptions;
+  error_code result = ds28c36.readMemory(DS28C36::romOptionsPage, romOptions);
+  if (!result) {
+    copy(romOptions.romId(), romId);
+    copy(romOptions.manId(), manId);
+  }
+  return result;
+}
+
+error_code enableCoprocessor(DS2476 & ds2476) {
+  DS2476::GpioControl gpioControl;
+  error_code result = ds2476.readMemory(DS2476::gpioControlPage, gpioControl);
+  if (!result) {
+    if (!gpioControl.pioaConducting()) {
+      gpioControl.setPioaConducting(true);
+      result = ds2476.writeMemory(DS2476::gpioControlPage, gpioControl);
+    }
+  }
+  return result;
+}
+
+static void setAnonymous(RomId::span romId) {
+  std::fill(romId.begin(), romId.end(), 0xFF);
+}
+
+DS28C36::PageAuthenticationData &
+DS28C36::PageAuthenticationData::setAnonymousRomId() {
+  setAnonymous(romId());
+  return *this;
+}
+
+DS28C36::EncryptionHmacData & DS28C36::EncryptionHmacData::setAnonymousRomId() {
+  setAnonymous(romId());
+  return *this;
+}
+
+} // namespace MaximInterface