absl::Status SignHash()

in kmscng/main/bridge.cc [400:454]
47 lines of code
5 McCabe index (conditional complexity)

absl::Status SignHash(__in NCRYPT_PROV_HANDLE hProvider,
                      __in NCRYPT_KEY_HANDLE hKey, __in_opt VOID* pPaddingInfo,
                      __in_bcount(cbHashValue) PBYTE pbHashValue,
                      __in DWORD cbHashValue,
                      __out_bcount_part_opt(cbSignature, *pcbResult)
                          PBYTE pbSignature,
                      __in DWORD cbSignature, __out DWORD* pcbResult,
                      __in DWORD dwFlags) {
  LOG_IF(INFO, std::getenv(kVerboseLoggingEnvVariable))
      << "SignHash invoked\n"
      << "Provider: " << hProvider << "\n"
      << "Key: " << hKey << "\n"
      << "Padding info: " << uintptr_t(pPaddingInfo) << "\n"
      << "Hash value: " << uintptr_t(pbHashValue) << "\n"
      << "Hash value size: " << cbHashValue << "\n"
      << "Signature: " << uintptr_t(pbSignature) << "\n"
      << "Signature size: " << cbSignature << "\n"
      << "Signature result size: " << uintptr_t(pcbResult) << "\n"
      << "Flags: " << dwFlags << "\n\n";
  ASSIGN_OR_RETURN(Object * object, ValidateKeyHandle(hProvider, hKey));
  if (!pbHashValue) {
    return NewInvalidArgumentError("pbHashValue cannot be null",
                                   NTE_INVALID_PARAMETER, SOURCE_LOCATION);
  }
  if (!pcbResult) {
    return NewInvalidArgumentError("pcbResult cannot be null",
                                   NTE_INVALID_PARAMETER, SOURCE_LOCATION);
  }
  RETURN_IF_ERROR(ValidateFlags(dwFlags));

  // Check key properties against the expected AlgorithmDetails.
  RETURN_IF_ERROR(ValidateKeyPreconditions(object));

  ASSIGN_OR_RETURN(size_t signature_length, SignatureLength(object));
  *pcbResult = static_cast<uint32_t>(signature_length);

  // Return size required to hold the signature if output buffer is null.
  if (!pbSignature) {
    return absl::OkStatus();
  }

  // Check provided buffer size to ensure the property value fits.
  if (cbSignature < *pcbResult) {
    return NewOutOfRangeError(
        absl::StrFormat("cbSignature size=%u not large enough to fit "
                        "property value of size %u",
                        cbSignature, *pcbResult),
        SOURCE_LOCATION);
  }

  RETURN_IF_ERROR(
      SignDigest(object, absl::Span<const uint8_t>(pbHashValue, cbHashValue),
                 absl::Span<uint8_t>(pbSignature, cbSignature)));
  return absl::OkStatus();
}