Diff: MaximInterfaceDevices/DS28C36_DS2476.cpp

Revision:

7:9cd16581b578

Child:

8:5ea891c7d1a1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MaximInterfaceDevices/DS28C36_DS2476.cpp	Mon Jul 22 11:44:07 2019 -0500
@@ -0,0 +1,725 @@
+/*******************************************************************************
+* 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 <MaximInterfaceCore/Error.hpp>
+#include <MaximInterfaceCore/I2CMaster.hpp>
+#include <MaximInterfaceCore/RomId.hpp>
+#include "DS28C36_DS2476.hpp"
+
+namespace MaximInterfaceDevices {
+
+using namespace Core;
+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,
+                                                     Page::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 + Page::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(Page::span hmac) {
+  error_code result = writeCommand(0x2D);
+  if (!result) {
+    sleep(sha256ComputationTimeMs);
+    array<uint_least8_t, 1 + Page::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::Page::array page;
+  error_code result = ds28c36.readMemory(DS28C36::romOptionsPage, page);
+  if (!result) {
+    const DS28C36::RomOptions romOptions(page);
+    copy(romOptions.romId(), romId);
+    copy(romOptions.manId(), manId);
+  }
+  return result;
+}
+
+error_code enableCoprocessor(DS2476 & ds2476) {
+  DS2476::Page::array page;
+  error_code result = ds2476.readMemory(DS2476::gpioControlPage, page);
+  if (!result) {
+    DS2476::GpioControl gpioControl(page);
+    if (!gpioControl.pioaConducting()) {
+      gpioControl.setPioaConducting(true);
+      result = ds2476.writeMemory(DS2476::gpioControlPage, page);
+    }
+  }
+  return result;
+}
+
+error_code enableRomId(DS2476 & ds2476) {
+  DS2476::Page::array page;
+  error_code result = ds2476.readMemory(DS2476::romOptionsPage, page);
+  if (!result) {
+    DS2476::RomOptions romOptions(page);
+    if (!romOptions.romBlockDisable()) {
+      romOptions.setRomBlockDisable(true);
+      result = ds2476.writeMemory(DS2476::romOptionsPage, page);
+    }
+  }
+  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 MaximInterfaceDevices