Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1349 insertions, 0 deletions

diff --git a/third_party/rlbox/include/rlbox.hpp b/third_party/rlbox/include/rlbox.hpp
new file mode 100644
index 0000000000..96daaac233
--- /dev/null
+++ b/third_party/rlbox/include/rlbox.hpp
@@ -0,0 +1,1349 @@
+#pragma once
+
+#include <array>
+#include <cstring>
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+#include "rlbox_app_pointer.hpp"
+#include "rlbox_conversion.hpp"
+#include "rlbox_helpers.hpp"
+#include "rlbox_policy_types.hpp"
+#include "rlbox_range.hpp"
+#include "rlbox_sandbox.hpp"
+#include "rlbox_stdlib.hpp"
+#include "rlbox_struct_support.hpp"
+#include "rlbox_type_traits.hpp"
+#include "rlbox_types.hpp"
+#include "rlbox_unwrap.hpp"
+#include "rlbox_wrapper_traits.hpp"
+
+namespace rlbox {
+
+template<template<typename, typename> typename T_Wrap,
+         typename T,
+         typename T_Sbx>
+class tainted_base_impl
+{
+  KEEP_CLASSES_FRIENDLY
+  KEEP_CAST_FRIENDLY
+
+public:
+  inline auto& impl() { return *static_cast<T_Wrap<T, T_Sbx>*>(this); }
+  inline auto& impl() const
+  {
+    return *static_cast<const T_Wrap<T, T_Sbx>*>(this);
+  }
+
+  /**
+   * @brief Unwrap a tainted value without verification. This is an unsafe
+   * operation and should be used with care.
+   */
+  inline auto UNSAFE_unverified() const { return impl().get_raw_value(); }
+  /**
+   * @brief Like UNSAFE_unverified, but get the underlying sandbox
+   * representation.
+   *
+   * @param sandbox Reference to sandbox.
+   *
+   * For the Wasm-based sandbox, this function additionally validates the
+   * unwrapped value against the machine model of the sandbox (LP32).
+   */
+  inline auto UNSAFE_sandboxed(rlbox_sandbox<T_Sbx>& sandbox) const
+  {
+    return impl().get_raw_sandbox_value(sandbox);
+  }
+
+  /**
+   * @brief Unwrap a tainted value without verification. This function should
+   * be used when unwrapping is safe.
+   *
+   * @param reason An explanation why the unverified unwrapping is safe.
+   */
+  template<size_t N>
+  inline auto unverified_safe_because(const char (&reason)[N]) const
+  {
+    RLBOX_UNUSED(reason);
+    static_assert(!std::is_pointer_v<T>,
+                  "unverified_safe_because does not support pointers. Use "
+                  "unverified_safe_pointer_because.");
+    return UNSAFE_unverified();
+  }
+
+  template<size_t N>
+  inline auto unverified_safe_pointer_because(size_t count,
+                                              const char (&reason)[N]) const
+  {
+    RLBOX_UNUSED(reason);
+
+    static_assert(std::is_pointer_v<T>, "Expected pointer type");
+    using T_Pointed = std::remove_pointer_t<T>;
+    if_constexpr_named(cond1, std::is_pointer_v<T_Pointed>)
+    {
+      rlbox_detail_static_fail_because(
+        cond1,
+        "There is no way to use unverified_safe_pointer_because for "
+        "'pointers to pointers' safely. Use copy_and_verify instead.");
+      return nullptr;
+    }
+
+    auto ret = UNSAFE_unverified();
+    if (ret != nullptr) {
+      size_t bytes = sizeof(T) * count;
+      detail::check_range_doesnt_cross_app_sbx_boundary<T_Sbx>(ret, bytes);
+    }
+    return ret;
+  }
+
+  inline auto INTERNAL_unverified_safe() const { return UNSAFE_unverified(); }
+
+#define BinaryOpValAndPtr(opSymbol)                                            \
+  template<typename T_Rhs>                                                     \
+  inline constexpr auto operator opSymbol(const T_Rhs& rhs)                    \
+    const->tainted<decltype(std::declval<T>() opSymbol std::declval<           \
+                            detail::rlbox_remove_wrapper_t<T_Rhs>>()),         \
+                   T_Sbx>                                                      \
+  {                                                                            \
+    static_assert(detail::is_basic_type_v<T>,                                  \
+                  "Operator " #opSymbol                                        \
+                  " only supported for primitive and pointer types");          \
+                                                                               \
+    auto raw_rhs = detail::unwrap_value(rhs);                                  \
+                                                                               \
+    if constexpr (std::is_pointer_v<T>) {                                      \
+      static_assert(std::is_integral_v<decltype(raw_rhs)>,                     \
+                    "Can only operate on numeric types");                      \
+      auto ptr = impl().get_raw_value();                                       \
+      detail::dynamic_check(ptr != nullptr,                                    \
+                            "Pointer arithmetic on a null pointer");           \
+      /* increment the target by size of the data structure */                 \
+      auto target =                                                            \
+        reinterpret_cast<uintptr_t>(ptr) opSymbol raw_rhs * sizeof(*impl());   \
+      auto no_overflow = rlbox_sandbox<T_Sbx>::is_in_same_sandbox(             \
+        reinterpret_cast<const void*>(ptr),                                    \
+        reinterpret_cast<const void*>(target));                                \
+      detail::dynamic_check(                                                   \
+        no_overflow,                                                           \
+        "Pointer arithmetic overflowed a pointer beyond sandbox memory");      \
+                                                                               \
+      return tainted<T, T_Sbx>::internal_factory(reinterpret_cast<T>(target)); \
+    } else {                                                                   \
+      auto raw = impl().get_raw_value();                                       \
+      auto ret = raw opSymbol raw_rhs;                                         \
+      using T_Ret = decltype(ret);                                             \
+      return tainted<T_Ret, T_Sbx>::internal_factory(ret);                     \
+    }                                                                          \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+  BinaryOpValAndPtr(+);
+  BinaryOpValAndPtr(-);
+
+#undef BinaryOpValAndPtr
+
+#define BinaryOp(opSymbol)                                                     \
+  template<typename T_Rhs>                                                     \
+  inline constexpr auto operator opSymbol(const T_Rhs& rhs)                    \
+    const->tainted<decltype(std::declval<T>() opSymbol std::declval<           \
+                            detail::rlbox_remove_wrapper_t<T_Rhs>>()),         \
+                   T_Sbx>                                                      \
+  {                                                                            \
+    static_assert(detail::is_fundamental_or_enum_v<T>,                         \
+                  "Operator " #opSymbol                                        \
+                  " only supported for primitive  types");                     \
+                                                                               \
+    auto raw = impl().get_raw_value();                                         \
+    auto raw_rhs = detail::unwrap_value(rhs);                                  \
+    static_assert(std::is_integral_v<decltype(raw_rhs)>                        \
+                  || std::is_floating_point_v<decltype(raw_rhs)>,              \
+                  "Can only operate on numeric types");                        \
+                                                                               \
+    auto ret = raw opSymbol raw_rhs;                                           \
+    using T_Ret = decltype(ret);                                               \
+    return tainted<T_Ret, T_Sbx>::internal_factory(ret);                       \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+  BinaryOp(*);
+  BinaryOp(/);
+  BinaryOp(%);
+  BinaryOp(^);
+  BinaryOp(&);
+  BinaryOp(|);
+  BinaryOp(<<);
+  BinaryOp(>>);
+
+#undef BinaryOp
+
+#define CompoundAssignmentOp(opSymbol)                                         \
+  template<typename T_Rhs>                                                     \
+  inline constexpr T_Wrap<T, T_Sbx>& operator opSymbol##=(const T_Rhs& rhs)    \
+  {                                                                            \
+    auto& this_ref = impl();                                                   \
+    this_ref = this_ref opSymbol rhs;                                          \
+    return this_ref;                                                           \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+  CompoundAssignmentOp(+);
+  CompoundAssignmentOp(-);
+  CompoundAssignmentOp(*);
+  CompoundAssignmentOp(/);
+  CompoundAssignmentOp(%);
+  CompoundAssignmentOp(^);
+  CompoundAssignmentOp(&);
+  CompoundAssignmentOp(|);
+  CompoundAssignmentOp(<<);
+  CompoundAssignmentOp(>>);
+
+#undef CompoundAssignmentOp
+
+#define PreIncDecOps(opSymbol)                                                 \
+  inline constexpr T_Wrap<T, T_Sbx>& operator opSymbol##opSymbol()             \
+  {                                                                            \
+    auto& this_ref = impl();                                                   \
+    this_ref = this_ref opSymbol 1;                                            \
+    return this_ref;                                                           \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+  PreIncDecOps(+);
+  PreIncDecOps(-);
+
+#undef PreIncDecOps
+
+#define PostIncDecOps(opSymbol)                                                \
+  inline constexpr T_Wrap<T, T_Sbx> operator opSymbol##opSymbol(int)           \
+  {                                                                            \
+    tainted<T, T_Sbx> ret = impl();                                            \
+    operator++();                                                              \
+    return ret;                                                                \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+  PostIncDecOps(+);
+  PostIncDecOps(-);
+
+#undef PostIncDecOps
+
+#define BooleanBinaryOp(opSymbol)                                              \
+  template<typename T_Rhs>                                                     \
+  inline constexpr auto operator opSymbol(const T_Rhs& rhs)                    \
+    const->tainted<decltype(std::declval<T>() opSymbol std::declval<           \
+                            detail::rlbox_remove_wrapper_t<T_Rhs>>()),         \
+                   T_Sbx>                                                      \
+  {                                                                            \
+    static_assert(detail::is_fundamental_or_enum_v<T>,                         \
+                  "Operator " #opSymbol                                        \
+                  " only supported for primitive  types");                     \
+                                                                               \
+    auto raw = impl().get_raw_value();                                         \
+    auto raw_rhs = detail::unwrap_value(rhs);                                  \
+    static_assert(std::is_integral_v<decltype(raw_rhs)>,                       \
+                  "Can only operate on numeric types");                        \
+                                                                               \
+    auto ret = raw opSymbol raw_rhs;                                           \
+    using T_Ret = decltype(ret);                                               \
+    return tainted<T_Ret, T_Sbx>::internal_factory(ret);                       \
+  }                                                                            \
+                                                                               \
+  template<typename T_Rhs>                                                     \
+  inline constexpr auto operator opSymbol(const T_Rhs&&)                       \
+    const->tainted<decltype(std::declval<T>() opSymbol std::declval<           \
+                            detail::rlbox_remove_wrapper_t<T_Rhs>>()),         \
+                   T_Sbx>                                                      \
+  {                                                                            \
+    rlbox_detail_static_fail_because(                                          \
+      detail::true_v<T_Rhs>,                                                   \
+      "C++ does not permit safe overloading of && and || operations as this "  \
+      "affects the short circuiting behaviour of these operations. RLBox "     \
+      "does let you use && and || with tainted in limited situations - when "  \
+      "all arguments starting from the second are local variables. It does "   \
+      "not allow it if arguments starting from the second  are expressions.\n" \
+      "For example the following is not allowed\n"                             \
+      "\n"                                                                     \
+      "tainted<bool, T_Sbx> a = true;\n"                                       \
+      "auto r = a && true && sandbox.invoke_sandbox_function(getBool);\n"      \
+      "\n"                                                                     \
+      "However the following would be allowed\n"                               \
+      "tainted<bool, T_Sbx> a = true;\n"                                       \
+      "auto b = true\n"                                                        \
+      "auto c = sandbox.invoke_sandbox_function(getBool);\n"                   \
+      "auto r = a && b && c;\n"                                                \
+      "\n"                                                                     \
+      "Note that these 2 programs are not identical. The first program may "   \
+      "or may not call getBool, while second program always calls getBool");   \
+    return tainted<bool, T_Sbx>(false);                                        \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+  BooleanBinaryOp(&&);
+  BooleanBinaryOp(||);
+
+#undef BooleanBinaryOp
+
+#define UnaryOp(opSymbol)                                                      \
+  inline auto operator opSymbol()                                              \
+  {                                                                            \
+    static_assert(detail::is_fundamental_or_enum_v<T>,                         \
+                  "Operator " #opSymbol " only supported for primitive");      \
+                                                                               \
+    auto raw = impl().get_raw_value();                                         \
+    auto ret = opSymbol raw;                                                   \
+    using T_Ret = decltype(ret);                                               \
+    return tainted<T_Ret, T_Sbx>::internal_factory(ret);                       \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+  UnaryOp(-);
+  UnaryOp(~);
+
+#undef UnaryOp
+
+/**
+ * @brief Comparison operators. Comparisons to values in sandbox memory can
+ * only return a "tainted_boolean_hint" as the values in memory can be
+ * incorrect or malicously change in the future.
+ *
+ * @tparam T_Rhs
+ * @param rhs
+ * @return One of either a bool, tainted<bool>, or a tainted_boolean_hint
+ * depending on the arguments to the binary expression.
+ */
+#define CompareOp(opSymbol, permit_pointers)                                   \
+  template<typename T_Rhs>                                                     \
+  inline constexpr auto operator opSymbol(const T_Rhs& rhs) const              \
+  {                                                                            \
+    using T_RhsNoQ = detail::remove_cv_ref_t<T_Rhs>;                           \
+    constexpr bool check_rhs_hint =                                            \
+      detail::rlbox_is_tainted_volatile_v<T_RhsNoQ> ||                         \
+      detail::rlbox_is_tainted_boolean_hint_v<T_RhsNoQ>;                       \
+    constexpr bool check_lhs_hint =                                            \
+      detail::rlbox_is_tainted_volatile_v<T_Wrap<T, T_Sbx>>;                   \
+    constexpr bool is_hint = check_lhs_hint || check_rhs_hint;                 \
+                                                                               \
+    constexpr bool is_unwrapped =                                              \
+      detail::rlbox_is_tainted_v<T_Wrap<T, T_Sbx>> &&                          \
+      std::is_null_pointer_v<T_RhsNoQ>;                                        \
+                                                                               \
+    /* Sanity check - can't be a hint and unwrapped */                         \
+    static_assert(is_hint ? !is_unwrapped : true,                              \
+                  "Internal error: Could not deduce type for comparison. "     \
+                  "Please file a bug.");                                       \
+                                                                               \
+    if constexpr (!permit_pointers && std::is_pointer_v<T>) {                  \
+      rlbox_detail_static_fail_because(                                        \
+        std::is_pointer_v<T>,                                                  \
+        "Only == and != comparisons are allowed for pointers");                \
+    }                                                                          \
+                                                                               \
+    bool ret = (impl().get_raw_value() opSymbol detail::unwrap_value(rhs));    \
+                                                                               \
+    if constexpr (is_hint) {                                                   \
+      return tainted_boolean_hint(ret);                                        \
+    } else if constexpr (is_unwrapped) {                                       \
+      return ret;                                                              \
+    } else {                                                                   \
+      return tainted<bool, T_Sbx>(ret);                                        \
+    }                                                                          \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+  CompareOp(==, true /* permit_pointers */);
+  CompareOp(!=, true /* permit_pointers */);
+  CompareOp(<, false /* permit_pointers */);
+  CompareOp(<=, false /* permit_pointers */);
+  CompareOp(>, false /* permit_pointers */);
+  CompareOp(>=, false /* permit_pointers */);
+
+#undef CompareOp
+
+private:
+  using T_OpSubscriptArrRet = std::conditional_t<
+    std::is_pointer_v<T>,
+    tainted_volatile<detail::dereference_result_t<T>, T_Sbx>, // is_pointer
+    T_Wrap<detail::dereference_result_t<T>, T_Sbx>            // is_array
+    >;
+
+public:
+  template<typename T_Rhs>
+  inline const T_OpSubscriptArrRet& operator[](T_Rhs&& rhs) const
+  {
+    static_assert(std::is_pointer_v<T> || detail::is_c_or_std_array_v<T>,
+                  "Operator [] supports pointers and arrays only");
+
+    auto raw_rhs = detail::unwrap_value(rhs);
+    static_assert(std::is_integral_v<decltype(raw_rhs)>,
+                  "Can only index with numeric types");
+
+    if constexpr (std::is_pointer_v<T>) {
+      auto ptr = this->impl().get_raw_value();
+
+      // increment the target by size of the data structure
+      auto target =
+        reinterpret_cast<uintptr_t>(ptr) + raw_rhs * sizeof(*this->impl());
+      auto no_overflow = rlbox_sandbox<T_Sbx>::is_in_same_sandbox(
+        ptr, reinterpret_cast<const void*>(target));
+      detail::dynamic_check(
+        no_overflow,
+        "Pointer arithmetic overflowed a pointer beyond sandbox memory");
+
+      auto target_wrap = tainted<const T, T_Sbx>::internal_factory(
+        reinterpret_cast<const T>(target));
+      return *target_wrap;
+    } else {
+      using T_Rhs_Unsigned = std::make_unsigned_t<decltype(raw_rhs)>;
+      detail::dynamic_check(
+        raw_rhs >= 0 && static_cast<T_Rhs_Unsigned>(raw_rhs) <
+                          std::extent_v<detail::std_array_to_c_arr_t<T>, 0>,
+        "Static array indexing overflow");
+
+      const void* target_ptr;
+      if constexpr (detail::rlbox_is_tainted_v<T_Wrap<T, T_Sbx>>) {
+        auto& data_ref = impl().get_raw_value_ref();
+        target_ptr = &(data_ref[raw_rhs]);
+      } else {
+        auto& data_ref = impl().get_sandbox_value_ref();
+        auto target_ptr_vol = &(data_ref[raw_rhs]);
+        // target_ptr is a volatile... remove this.
+        // Safe as we will return a tainted_volatile if this is the case
+        target_ptr = detail::remove_volatile_from_ptr_cast(target_ptr_vol);
+      }
+
+      using T_Target = const T_Wrap<detail::dereference_result_t<T>, T_Sbx>;
+      auto wrapped_target_ptr = reinterpret_cast<T_Target*>(target_ptr);
+      return *wrapped_target_ptr;
+    }
+  }
+
+  template<typename T_Rhs>
+  inline T_OpSubscriptArrRet& operator[](T_Rhs&& rhs)
+  {
+    return const_cast<T_OpSubscriptArrRet&>(std::as_const(*this)[rhs]);
+  }
+
+private:
+  using T_OpDerefRet = tainted_volatile<std::remove_pointer_t<T>, T_Sbx>;
+
+public:
+  inline T_OpDerefRet& operator*() const
+  {
+    static_assert(std::is_pointer_v<T>, "Operator * only allowed on pointers");
+    auto ret_ptr_const =
+      reinterpret_cast<const T_OpDerefRet*>(impl().get_raw_value());
+    // Safe - If T_OpDerefRet is not a const ptr, this is trivially safe
+    //        If T_OpDerefRet is a const ptr, then the const is captured
+    //        inside the wrapper
+    auto ret_ptr = const_cast<T_OpDerefRet*>(ret_ptr_const);
+    return *ret_ptr;
+  }
+
+  // We need to implement the -> operator even if T is not a struct
+  // So that we can support code patterns such as the below
+  // tainted<T*> a;
+  // a->UNSAFE_unverified();
+  inline const T_OpDerefRet* operator->() const
+  {
+    static_assert(std::is_pointer_v<T>,
+                  "Operator -> only supported for pointer types");
+    return reinterpret_cast<const T_OpDerefRet*>(impl().get_raw_value());
+  }
+
+  inline T_OpDerefRet* operator->()
+  {
+    return const_cast<T_OpDerefRet*>(std::as_const(*this).operator->());
+  }
+
+  inline auto operator!()
+  {
+    if_constexpr_named(cond1, std::is_pointer_v<T>)
+    {
+      return impl() == nullptr;
+    }
+    else if_constexpr_named(cond2, std::is_same_v<std::remove_cv_t<T>, bool>)
+    {
+      return impl() == false;
+    }
+    else
+    {
+      auto unknownCase = !(cond1 || cond2);
+      rlbox_detail_static_fail_because(
+        unknownCase,
+        "Operator ! only permitted for pointer or boolean types. For other"
+        "types, unwrap the tainted value with the copy_and_verify API and then"
+        "use operator !");
+    }
+  }
+
+  /**
+   * @brief Copy tainted value from sandbox and verify it.
+   *
+   * @param verifier Function used to verify the copied value.
+   * @tparam T_Func the type of the verifier.
+   * @return Whatever the verifier function returns.
+   */
+  template<typename T_Func>
+  inline auto copy_and_verify(T_Func verifier) const
+  {
+    using T_Deref = std::remove_cv_t<std::remove_pointer_t<T>>;
+
+    if_constexpr_named(cond1, detail::is_fundamental_or_enum_v<T>)
+    {
+      auto val = impl().get_raw_value();
+      return verifier(val);
+    }
+    else if_constexpr_named(
+      cond2, detail::is_one_level_ptr_v<T> && !std::is_class_v<T_Deref>)
+    {
+      // Some paths don't use the verifier
+      RLBOX_UNUSED(verifier);
+
+      if_constexpr_named(subcond1, std::is_void_v<T_Deref>)
+      {
+        rlbox_detail_static_fail_because(
+          subcond1,
+          "copy_and_verify not recommended for void* as it could lead to some "
+          "anti-patterns in verifiers. Cast it to a different tainted pointer "
+          "with sandbox_reinterpret_cast and then call copy_and_verify. "
+          "Alternately, you can use the UNSAFE_unverified API to do this "
+          "without casting.");
+        return nullptr;
+      }
+      // Test with detail::is_func_ptr_v to check for member funcs also
+      else if_constexpr_named(subcond2, detail::is_func_ptr_v<T>)
+      {
+        rlbox_detail_static_fail_because(
+          subcond2,
+          "copy_and_verify cannot be applied to function pointers as this "
+          "makes a deep copy. This is not possible for function pointers. "
+          "Consider copy_and_verify_address instead.");
+        return nullptr;
+      }
+      else
+      {
+        auto val = impl().get_raw_value();
+        if (val == nullptr) {
+          return verifier(nullptr);
+        } else {
+          // Important to assign to a local variable (i.e. make a copy)
+          // Else, for tainted_volatile, this will allow a
+          // time-of-check-time-of-use attack
+          auto val_copy = std::make_unique<T_Deref>();
+          *val_copy = *val;
+          return verifier(std::move(val_copy));
+        }
+      }
+    }
+    else if_constexpr_named(
+      cond3, detail::is_one_level_ptr_v<T> && std::is_class_v<T_Deref>)
+    {
+      auto val_copy = std::make_unique<tainted<T_Deref, T_Sbx>>(*impl());
+      return verifier(std::move(val_copy));
+    }
+    else if_constexpr_named(cond4, std::is_array_v<T>)
+    {
+      static_assert(
+        detail::is_fundamental_or_enum_v<std::remove_all_extents_t<T>>,
+        "copy_and_verify on arrays is only safe for fundamental or enum types. "
+        "For arrays of other types, apply copy_and_verify on each element "
+        "individually --- a[i].copy_and_verify(...)");
+
+      auto copy = impl().get_raw_value();
+      return verifier(copy);
+    }
+    else
+    {
+      auto unknownCase = !(cond1 || cond2 || cond3 || cond4);
+      rlbox_detail_static_fail_because(
+        unknownCase,
+        "copy_and_verify not supported for this type as it may be unsafe");
+    }
+  }
+
+private:
+  using T_CopyAndVerifyRangeEl =
+    detail::valid_array_el_t<std::remove_cv_t<std::remove_pointer_t<T>>>;
+
+  // Template needed to ensure that function isn't instantiated for unsupported
+  // types like function pointers which causes compile errors...
+  template<typename T2 = T>
+  inline const void* verify_range_helper(std::size_t count) const
+  {
+    static_assert(std::is_pointer_v<T>);
+    static_assert(detail::is_fundamental_or_enum_v<T_CopyAndVerifyRangeEl>);
+
+    detail::dynamic_check(
+      count != 0,
+      "Called copy_and_verify_range/copy_and_verify_string with count 0");
+
+    auto start = reinterpret_cast<const void*>(impl().get_raw_value());
+    if (start == nullptr) {
+      return nullptr;
+    }
+
+    detail::check_range_doesnt_cross_app_sbx_boundary<T_Sbx>(
+      start, count * sizeof(T_CopyAndVerifyRangeEl));
+
+    return start;
+  }
+
+  template<typename T2 = T>
+  inline std::unique_ptr<T_CopyAndVerifyRangeEl[]> copy_and_verify_range_helper(
+    std::size_t count) const
+  {
+    const void* start = verify_range_helper(count);
+    if (start == nullptr) {
+      return nullptr;
+    }
+
+    auto target = std::make_unique<T_CopyAndVerifyRangeEl[]>(count);
+
+    for (size_t i = 0; i < count; i++) {
+      auto p_src_i_tainted = &(impl()[i]);
+      auto p_src_i = p_src_i_tainted.get_raw_value();
+      detail::convert_type_fundamental_or_array(target[i], *p_src_i);
+    }
+
+    return target;
+  }
+
+public:
+  /**
+   * @brief Copy a range of tainted values from sandbox and verify them.
+   *
+   * @param verifier Function used to verify the copied value.
+   * @param count Number of elements to copy.
+   * @tparam T_Func the type of the verifier. If the tainted type is ``int*``
+   * then ``T_Func = T_Ret(*)(unique_ptr<int[]>)``.
+   * @return Whatever the verifier function returns.
+   */
+  template<typename T_Func>
+  inline auto copy_and_verify_range(T_Func verifier, std::size_t count) const
+  {
+    static_assert(std::is_pointer_v<T>,
+                  "Can only call copy_and_verify_range on pointers");
+
+    static_assert(
+      detail::is_fundamental_or_enum_v<T_CopyAndVerifyRangeEl>,
+      "copy_and_verify_range is only safe for ranges of "
+      "fundamental or enum types. For other types, call "
+      "copy_and_verify on each element --- a[i].copy_and_verify(...)");
+
+    std::unique_ptr<T_CopyAndVerifyRangeEl[]> target =
+      copy_and_verify_range_helper(count);
+    return verifier(std::move(target));
+  }
+
+  /**
+   * @brief Copy a tainted string from sandbox and verify it.
+   *
+   * @param verifier Function used to verify the copied value.
+   * @tparam T_Func the type of the verifier either
+   * ``T_Ret(*)(unique_ptr<char[]>)`` or ``T_Ret(*)(std::string)``
+   * @return Whatever the verifier function returns.
+   */
+  template<typename T_Func>
+  inline auto copy_and_verify_string(T_Func verifier) const
+  {
+    static_assert(std::is_pointer_v<T>,
+                  "Can only call copy_and_verify_string on pointers");
+
+    static_assert(std::is_same_v<char, T_CopyAndVerifyRangeEl>,
+                  "copy_and_verify_string only allows char*");
+
+    using T_VerifParam = detail::func_first_arg_t<T_Func>;
+
+    auto start = impl().get_raw_value();
+    if_constexpr_named(
+      cond1,
+      std::is_same_v<T_VerifParam, std::unique_ptr<char[]>> ||
+        std::is_same_v<T_VerifParam, std::unique_ptr<const char[]>>)
+    {
+      if (start == nullptr) {
+        return verifier(nullptr);
+      }
+
+      // it is safe to run strlen on a tainted<string> as worst case, the string
+      // does not have a null and we try to copy all the memory out of the
+      // sandbox however, copy_and_verify_range ensures that we never copy
+      // memory outsider the range
+      auto str_len = std::strlen(start) + 1;
+      std::unique_ptr<T_CopyAndVerifyRangeEl[]> target =
+        copy_and_verify_range_helper(str_len);
+
+      // ensure the string has a trailing null
+      target[str_len - 1] = '\0';
+
+      return verifier(std::move(target));
+    }
+    else if_constexpr_named(cond2, std::is_same_v<T_VerifParam, std::string>)
+    {
+      if (start == nullptr) {
+        std::string param = "";
+        return verifier(param);
+      }
+
+      // it is safe to run strlen on a tainted<string> as worst case, the string
+      // does not have a null and we try to copy all the memory out of the
+      // sandbox however, copy_and_verify_range ensures that we never copy
+      // memory outsider the range
+      auto str_len = std::strlen(start) + 1;
+
+      const char* checked_start = (const char*)verify_range_helper(str_len);
+      if (checked_start == nullptr) {
+        std::string param = "";
+        return verifier(param);
+      }
+
+      std::string copy(checked_start, str_len - 1);
+      return verifier(std::move(copy));
+    }
+    else
+    {
+      constexpr bool unknownCase = !(cond1 || cond2);
+      rlbox_detail_static_fail_because(
+        unknownCase,
+        "copy_and_verify_string verifier parameter should either be "
+        "unique_ptr<char[]>, unique_ptr<const char[]> or std::string");
+    }
+  }
+
+  /**
+   * @brief Copy a tainted pointer from sandbox and verify the address.
+   *
+   * This function is useful if you need to verify physical bits representing
+   * the address of a pointer. Other APIs such as copy_and_verify performs a
+   * deep copy and changes the address bits.
+   *
+   * @param verifier Function used to verify the copied value.
+   * @tparam T_Func the type of the verifier ``T_Ret(*)(uintptr_t)``
+   * @return Whatever the verifier function returns.
+   */
+  template<typename T_Func>
+  inline auto copy_and_verify_address(T_Func verifier) const
+  {
+    static_assert(std::is_pointer_v<T>,
+                  "copy_and_verify_address must be used on pointers");
+    auto val = reinterpret_cast<uintptr_t>(impl().get_raw_value());
+    return verifier(val);
+  }
+
+  /**
+   * @brief Copy a tainted pointer to a buffer from sandbox and verify the
+   * address.
+   *
+   * This function is useful if you need to verify physical bits representing
+   * the address of a buffer. Other APIs such as copy_and_verify performs a
+   * deep copy and changes the address bits.
+   *
+   * @param verifier Function used to verify the copied value.
+   * @param size Size of the buffer. Buffer with length size is expected to fit
+   * inside sandbox memory.
+   * @tparam T_Func the type of the verifier ``T_Ret(*)(uintptr_t)``
+   * @return Whatever the verifier function returns.
+   */
+  template<typename T_Func>
+  inline auto copy_and_verify_buffer_address(T_Func verifier,
+                                             std::size_t size) const
+  {
+    static_assert(std::is_pointer_v<T>,
+                  "copy_and_verify_address must be used on pointers");
+    auto val = reinterpret_cast<uintptr_t>(verify_range_helper(size));
+    return verifier(val);
+  }
+};
+
+#define BinaryOpWrappedRhs(opSymbol)                                           \
+  template<template<typename, typename> typename T_Wrap,                       \
+           typename T,                                                         \
+           typename T_Sbx,                                                     \
+           typename T_Lhs,                                                     \
+           RLBOX_ENABLE_IF(!detail::rlbox_is_wrapper_v<T_Lhs> &&               \
+                           !detail::rlbox_is_tainted_boolean_hint_v<T_Lhs>)>   \
+  inline constexpr auto operator opSymbol(                                     \
+    const T_Lhs& lhs, const tainted_base_impl<T_Wrap, T, T_Sbx>& rhs)          \
+  {                                                                            \
+    /* Handles the case for "3 + tainted", where + is a binary op */           \
+    /* Technically pointer arithmetic can be performed as 3 + tainted_ptr */   \
+    /* as well. However, this is unusual and to keep the code simple we do */  \
+    /* not support this. */                                                    \
+    static_assert(                                                             \
+      std::is_arithmetic_v<T_Lhs>,                                             \
+      "Binary expressions between an non tainted type and tainted"             \
+      "type is only permitted if the first value is the tainted type. Try "    \
+      "changing the order of the binary expression accordingly");              \
+    auto ret = tainted<T_Lhs, T_Sbx>(lhs) opSymbol rhs.impl();                 \
+    return ret;                                                                \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+BinaryOpWrappedRhs(+);
+BinaryOpWrappedRhs(-);
+BinaryOpWrappedRhs(*);
+BinaryOpWrappedRhs(/);
+BinaryOpWrappedRhs(%);
+BinaryOpWrappedRhs(^);
+BinaryOpWrappedRhs(&);
+BinaryOpWrappedRhs(|);
+BinaryOpWrappedRhs(<<);
+BinaryOpWrappedRhs(>>);
+BinaryOpWrappedRhs(==);
+BinaryOpWrappedRhs(!=);
+BinaryOpWrappedRhs(<);
+BinaryOpWrappedRhs(<=);
+BinaryOpWrappedRhs(>);
+BinaryOpWrappedRhs(>=);
+#undef BinaryOpWrappedRhs
+
+#define BooleanBinaryOpWrappedRhs(opSymbol)                                    \
+  template<template<typename, typename> typename T_Wrap,                       \
+           typename T,                                                         \
+           typename T_Sbx,                                                     \
+           typename T_Lhs,                                                     \
+           RLBOX_ENABLE_IF(!detail::rlbox_is_wrapper_v<T_Lhs> &&               \
+                           !detail::rlbox_is_tainted_boolean_hint_v<T_Lhs>)>   \
+  inline constexpr auto operator opSymbol(                                     \
+    const T_Lhs& lhs, const tainted_base_impl<T_Wrap, T, T_Sbx>& rhs)          \
+  {                                                                            \
+    static_assert(                                                             \
+      std::is_arithmetic_v<T_Lhs>,                                             \
+      "Binary expressions between an non tainted type and tainted"             \
+      "type is only permitted if the first value is the tainted type. Try "    \
+      "changing the order of the binary expression accordingly");              \
+    auto ret = tainted<T_Lhs, T_Sbx>(lhs) opSymbol rhs.impl();                 \
+    return ret;                                                                \
+  }                                                                            \
+                                                                               \
+  template<template<typename, typename> typename T_Wrap,                       \
+           typename T,                                                         \
+           typename T_Sbx,                                                     \
+           typename T_Lhs,                                                     \
+           RLBOX_ENABLE_IF(!detail::rlbox_is_wrapper_v<T_Lhs> &&               \
+                           !detail::rlbox_is_tainted_boolean_hint_v<T_Lhs>)>   \
+  inline constexpr auto operator opSymbol(                                     \
+    const T_Lhs&, const tainted_base_impl<T_Wrap, T, T_Sbx>&&)                 \
+  {                                                                            \
+    rlbox_detail_static_fail_because(                                          \
+      detail::true_v<T_Lhs>,                                                   \
+      "C++ does not permit safe overloading of && and || operations as this "  \
+      "affects the short circuiting behaviour of these operations. RLBox "     \
+      "does let you use && and || with tainted in limited situations - when "  \
+      "all arguments starting from the second are local variables. It does "   \
+      "not allow it if arguments starting from the second  are expressions.\n" \
+      "For example the following is not allowed\n"                             \
+      "\n"                                                                     \
+      "tainted<bool, T_Sbx> a = true;\n"                                       \
+      "auto r = a && true && sandbox.invoke_sandbox_function(getBool);\n"      \
+      "\n"                                                                     \
+      "However the following would be allowed\n"                               \
+      "tainted<bool, T_Sbx> a = true;\n"                                       \
+      "auto b = true\n"                                                        \
+      "auto c = sandbox.invoke_sandbox_function(getBool);\n"                   \
+      "auto r = a && b && c;\n"                                                \
+      "\n"                                                                     \
+      "Note that these 2 programs are not identical. The first program may "   \
+      "or may not call getBool, while second program always calls getBool");   \
+    return tainted<bool, T_Sbx>(false);                                        \
+  }                                                                            \
+  RLBOX_REQUIRE_SEMI_COLON
+
+BooleanBinaryOpWrappedRhs(&&);
+BooleanBinaryOpWrappedRhs(||);
+#undef BooleanBinaryOpWrappedRhs
+
+namespace tainted_detail {
+  template<typename T, typename T_Sbx>
+  using tainted_repr_t = detail::c_to_std_array_t<T>;
+
+  template<typename T, typename T_Sbx>
+  using tainted_vol_repr_t =
+    detail::c_to_std_array_t<std::add_volatile_t<typename rlbox_sandbox<
+      T_Sbx>::template convert_to_sandbox_equivalent_nonclass_t<T>>>;
+}
+
+/**
+ * @brief Tainted values represent untrusted values that originate from the
+ * sandbox.
+ */
+template<typename T, typename T_Sbx>
+class tainted : public tainted_base_impl<tainted, T, T_Sbx>
+{
+  KEEP_CLASSES_FRIENDLY
+  KEEP_CAST_FRIENDLY
+
+  // Classes recieve their own specialization
+  static_assert(
+    !std::is_class_v<T>,
+    "Missing definition for class T. This error occurs for one "
+    "of 2 reasons.\n"
+    "  1) Make sure you have include a call rlbox_load_structs_from_library "
+    "for this library with this class included.\n"
+    "  2) Make sure you run (re-run) the struct-dump tool to list "
+    "all structs in use by your program.\n");
+
+  static_assert(
+    detail::is_basic_type_v<T> || std::is_array_v<T>,
+    "Tainted types only support fundamental, enum, pointer, array and struct "
+    "types. Please file a bug if more support is needed.");
+
+private:
+  using T_ClassBase = tainted_base_impl<tainted, T, T_Sbx>;
+  using T_AppType = tainted_detail::tainted_repr_t<T, T_Sbx>;
+  using T_SandboxedType = tainted_detail::tainted_vol_repr_t<T, T_Sbx>;
+  T_AppType data;
+
+  inline auto& get_raw_value_ref() noexcept { return data; }
+  inline auto& get_raw_value_ref() const noexcept { return data; }
+
+  inline std::remove_cv_t<T_AppType> get_raw_value() const noexcept
+  {
+    return data;
+  }
+
+  inline std::remove_cv_t<T_SandboxedType> get_raw_sandbox_value(
+    rlbox_sandbox<T_Sbx>& sandbox) const
+  {
+    std::remove_cv_t<T_SandboxedType> ret;
+
+    using namespace detail;
+    convert_type_non_class<T_Sbx,
+                           adjust_type_direction::TO_SANDBOX,
+                           adjust_type_context::SANDBOX>(
+      ret, data, nullptr /* example_unsandboxed_ptr */, &sandbox);
+    return ret;
+  };
+
+  inline const void* find_example_pointer_or_null() const noexcept
+  {
+    if constexpr (std::is_array_v<T>) {
+      auto& data_ref = get_raw_value_ref();
+
+      for (size_t i = 0; i < std::extent_v<T>; i++) {
+        const void* ret = data[i].find_example_pointer_or_null();
+        if (ret != nullptr) {
+          return ret;
+        }
+      }
+    } else if constexpr (std::is_pointer_v<T> && !detail::is_func_ptr_v<T>) {
+      auto data = get_raw_value();
+      return data;
+    }
+    return nullptr;
+  }
+
+  // Initializing with a pointer is dangerous and permitted only internally
+  template<typename T2 = T, RLBOX_ENABLE_IF(std::is_pointer_v<T2>)>
+  tainted(T2 val, const void* /* internal_tag */)
+    : data(val)
+  {
+    // Sanity check
+    static_assert(std::is_pointer_v<T>);
+  }
+
+  template<typename T_Rhs>
+  static inline tainted<T, T_Sbx> internal_factory(T_Rhs&& rhs)
+  {
+    if constexpr (std::is_pointer_v<std::remove_reference_t<T_Rhs>>) {
+      const void* internal_tag = nullptr;
+      return tainted(std::forward<T_Rhs>(rhs), internal_tag);
+    } else {
+      return tainted(std::forward<T_Rhs>(rhs));
+    }
+  }
+
+public:
+  tainted() = default;
+  tainted(const tainted<T, T_Sbx>& p) = default;
+
+  tainted(const tainted_volatile<T, T_Sbx>& p)
+  {
+    // Need to construct an example_unsandboxed_ptr for pointers or arrays of
+    // pointers. Since tainted_volatile is the type of data in sandbox memory,
+    // the address of data (&data) refers to a location in sandbox memory and
+    // can thus be the example_unsandboxed_ptr
+    const volatile void* p_data_ref = &p.get_sandbox_value_ref();
+    const void* example_unsandboxed_ptr = const_cast<const void*>(p_data_ref);
+    using namespace detail;
+    convert_type_non_class<T_Sbx,
+                           adjust_type_direction::TO_APPLICATION,
+                           adjust_type_context::EXAMPLE>(
+      get_raw_value_ref(),
+      p.get_sandbox_value_ref(),
+      example_unsandboxed_ptr,
+      nullptr /* sandbox_ptr */);
+  }
+
+  // Initializing with a pointer is dangerous and permitted only internally
+  template<typename T2 = T, RLBOX_ENABLE_IF(std::is_pointer_v<T2>)>
+  tainted(T2 val)
+    : data(val)
+  {
+    rlbox_detail_static_fail_because(
+      std::is_pointer_v<T2>,
+      "Assignment of pointers is not safe as it could\n "
+      "1) Leak pointers from the appliction to the sandbox which may break "
+      "ASLR\n "
+      "2) Pass inaccessible pointers to the sandbox leading to crash\n "
+      "3) Break sandboxes that require pointers to be swizzled first\n "
+      "\n "
+      "Instead, if you want to pass in a pointer, do one of the following\n "
+      "1) Allocate with malloc_in_sandbox, and pass in a tainted pointer\n "
+      "2) For pointers that point to functions in the application, register "
+      "with sandbox.register_callback(\"foo\"), and pass in the registered "
+      "value\n "
+      "3) For pointers that point to functions in the sandbox, get the "
+      "address with get_sandbox_function_address(sandbox, foo), and pass in "
+      "the "
+      "address\n "
+      "4) For raw pointers, use assign_raw_pointer which performs required "
+      "safety checks\n ");
+  }
+
+  tainted(
+    const sandbox_callback<
+      detail::function_ptr_t<T> // Need to ensure we never generate code that
+                                // creates a sandbox_callback of a non function
+      ,
+      T_Sbx>&)
+  {
+    rlbox_detail_static_fail_because(
+      detail::true_v<T>,
+      "RLBox does not support assigning sandbox_callback values to tainted "
+      "types (i.e. types that live in application memory).\n"
+      "If you still want to do this, consider changing your code to store the "
+      "value in sandbox memory as follows. Convert\n\n"
+      "sandbox_callback<T_Func, Sbx> cb = ...;\n"
+      "tainted<T_Func, Sbx> foo = cb;\n\n"
+      "to\n\n"
+      "tainted<T_Func*, Sbx> foo_ptr = sandbox.malloc_in_sandbox<T_Func*>();\n"
+      "*foo_ptr = cb;\n\n"
+      "This would keep the assignment in sandbox memory");
+  }
+
+  tainted(const std::nullptr_t& arg)
+    : data(arg)
+  {
+    static_assert(std::is_pointer_v<T>);
+  }
+
+  // We explicitly disable this constructor if it has one of the signatures
+  // above, so that we give the above constructors a higher priority. We only
+  // allow this for fundamental types as this is potentially unsafe for pointers
+  // and structs
+  template<typename T_Arg,
+           RLBOX_ENABLE_IF(
+             !detail::rlbox_is_wrapper_v<std::remove_reference_t<T_Arg>> &&
+             detail::is_fundamental_or_enum_v<T> &&
+             detail::is_fundamental_or_enum_v<std::remove_reference_t<T_Arg>>)>
+  tainted(T_Arg&& arg)
+    : data(std::forward<T_Arg>(arg))
+  {}
+
+  template<typename T_Rhs>
+  void assign_raw_pointer(rlbox_sandbox<T_Sbx>& sandbox, T_Rhs val)
+  {
+    static_assert(std::is_pointer_v<T_Rhs>, "Must be a pointer");
+    static_assert(std::is_assignable_v<T&, T_Rhs>,
+                  "Should assign pointers of compatible types.");
+    // Maybe a function pointer, so we need to cast
+    const void* cast_val = reinterpret_cast<const void*>(val);
+    bool safe = sandbox.is_pointer_in_sandbox_memory(cast_val);
+    detail::dynamic_check(
+      safe,
+      "Tried to assign a pointer that is not in the sandbox.\n "
+      "This is not safe as it could\n "
+      "1) Leak pointers from the appliction to the sandbox which may break "
+      "ASLR\n "
+      "2) Pass inaccessible pointers to the sandbox leading to crash\n "
+      "3) Break sandboxes that require pointers to be swizzled first\n "
+      "\n "
+      "Instead, if you want to pass in a pointer, do one of the following\n "
+      "1) Allocate with malloc_in_sandbox, and pass in a tainted pointer\n "
+      "2) For pointers that point to functions in the application, register "
+      "with sandbox.register_callback(\"foo\"), and pass in the registered "
+      "value\n "
+      "3) For pointers that point to functions in the sandbox, get the "
+      "address with get_sandbox_function_address(sandbox, foo), and pass in "
+      "the "
+      "address\n ");
+    data = val;
+  }
+
+  inline tainted_opaque<T, T_Sbx> to_opaque()
+  {
+    return *reinterpret_cast<tainted_opaque<T, T_Sbx>*>(this);
+  }
+
+  template<typename T_Dummy = void>
+  operator bool() const
+  {
+    if_constexpr_named(cond1, std::is_pointer_v<T>)
+    {
+      // We return this without the tainted wrapper as the checking for null
+      // doesn't really "induce" tainting in the application If the
+      // application is checking this pointer for null, then it is robust to
+      // this pointer being null or not null
+      return get_raw_value() != nullptr;
+    }
+    else
+    {
+      auto unknownCase = !(cond1);
+      rlbox_detail_static_fail_because(
+        unknownCase,
+        "Implicit conversion to bool is only permitted for pointer types. For "
+        "other types, unwrap the tainted value with the copy_and_verify API "
+        "and then perform the required checks");
+    }
+  }
+};
+
+template<typename T, typename T_Sbx>
+inline tainted<T, T_Sbx> from_opaque(tainted_opaque<T, T_Sbx> val)
+{
+  return *reinterpret_cast<tainted<T, T_Sbx>*>(&val);
+}
+
+/**
+ * @brief Tainted volatile values are like tainted values but still point to
+ * sandbox memory. Dereferencing a tainted pointer produces a tainted_volatile.
+ */
+template<typename T, typename T_Sbx>
+class tainted_volatile : public tainted_base_impl<tainted_volatile, T, T_Sbx>
+{
+  KEEP_CLASSES_FRIENDLY
+  KEEP_CAST_FRIENDLY
+
+  // Classes recieve their own specialization
+  static_assert(
+    !std::is_class_v<T>,
+    "Missing definition for class T. This error occurs for one "
+    "of 2 reasons.\n"
+    "  1) Make sure you have include a call rlbox_load_structs_from_library "
+    "for this library with this class included.\n"
+    "  2) Make sure you run (re-run) the struct-dump tool to list "
+    "all structs in use by your program.\n");
+
+  static_assert(
+    detail::is_basic_type_v<T> || std::is_array_v<T>,
+    "Tainted types only support fundamental, enum, pointer, array and struct "
+    "types. Please file a bug if more support is needed.");
+
+private:
+  using T_ClassBase = tainted_base_impl<tainted_volatile, T, T_Sbx>;
+  using T_AppType = tainted_detail::tainted_repr_t<T, T_Sbx>;
+  using T_SandboxedType = tainted_detail::tainted_vol_repr_t<T, T_Sbx>;
+  T_SandboxedType data;
+
+  inline auto& get_sandbox_value_ref() noexcept { return data; }
+  inline auto& get_sandbox_value_ref() const noexcept { return data; }
+
+  inline std::remove_cv_t<T_AppType> get_raw_value() const
+  {
+    std::remove_cv_t<T_AppType> ret;
+    // Need to construct an example_unsandboxed_ptr for pointers or arrays of
+    // pointers. Since tainted_volatile is the type of data in sandbox memory,
+    // the address of data (&data) refers to a location in sandbox memory and
+    // can thus be the example_unsandboxed_ptr
+    const volatile void* data_ref = &data;
+    const void* example_unsandboxed_ptr = const_cast<const void*>(data_ref);
+    using namespace detail;
+    convert_type_non_class<T_Sbx,
+                           adjust_type_direction::TO_APPLICATION,
+                           adjust_type_context::EXAMPLE>(
+      ret, data, example_unsandboxed_ptr, nullptr /* sandbox_ptr */);
+    return ret;
+  }
+
+  inline std::remove_cv_t<T_SandboxedType> get_raw_sandbox_value()
+    const noexcept
+  {
+    return data;
+  };
+
+  inline std::remove_cv_t<T_SandboxedType> get_raw_sandbox_value(
+    rlbox_sandbox<T_Sbx>& sandbox) const noexcept
+  {
+    RLBOX_UNUSED(sandbox);
+    return data;
+  };
+
+  tainted_volatile() = default;
+  tainted_volatile(const tainted_volatile<T, T_Sbx>& p) = default;
+
+public:
+  inline tainted<const T*, T_Sbx> operator&() const noexcept
+  {
+    auto ref =
+      detail::remove_volatile_from_ptr_cast(&this->get_sandbox_value_ref());
+    auto ref_cast = reinterpret_cast<const T*>(ref);
+    return tainted<const T*, T_Sbx>::internal_factory(ref_cast);
+  }
+
+  inline tainted<T*, T_Sbx> operator&() noexcept
+  {
+    return sandbox_const_cast<T*>(&std::as_const(*this));
+  }
+
+  // Needed as the definition of unary & above shadows the base's binary &
+  rlbox_detail_forward_binop_to_base(&, T_ClassBase);
+
+  template<typename T_RhsRef>
+  inline tainted_volatile<T, T_Sbx>& operator=(T_RhsRef&& val)
+  {
+    using T_Rhs = std::remove_reference_t<T_RhsRef>;
+    using T_Rhs_El = std::remove_all_extents_t<T_Rhs>;
+
+    // Need to construct an example_unsandboxed_ptr for pointers or arrays of
+    // pointers. Since tainted_volatile is the type of data in sandbox memory,
+    // the address of data (&data) refers to a location in sandbox memory and
+    // can thus be the example_unsandboxed_ptr
+    const volatile void* data_ref = &get_sandbox_value_ref();
+    const void* example_unsandboxed_ptr = const_cast<const void*>(data_ref);
+    // Some branches don't use this
+    RLBOX_UNUSED(example_unsandboxed_ptr);
+
+    if_constexpr_named(
+      cond1, std::is_same_v<std::remove_const_t<T_Rhs>, std::nullptr_t>)
+    {
+      static_assert(std::is_pointer_v<T>,
+                    "Null pointer can only be assigned to pointers");
+      // assign using an integer instead of nullptr, as the pointer field may be
+      // represented as integer
+      data = 0;
+    }
+    else if_constexpr_named(cond2, detail::rlbox_is_tainted_v<T_Rhs>)
+    {
+      using namespace detail;
+      convert_type_non_class<T_Sbx,
+                             adjust_type_direction::TO_SANDBOX,
+                             adjust_type_context::EXAMPLE>(
+        get_sandbox_value_ref(),
+        val.get_raw_value_ref(),
+        example_unsandboxed_ptr,
+        nullptr /* sandbox_ptr */);
+    }
+    else if_constexpr_named(cond3, detail::rlbox_is_tainted_volatile_v<T_Rhs>)
+    {
+      using namespace detail;
+      convert_type_non_class<T_Sbx,
+                             adjust_type_direction::NO_CHANGE,
+                             adjust_type_context::EXAMPLE>(
+        get_sandbox_value_ref(),
+        val.get_sandbox_value_ref(),
+        example_unsandboxed_ptr,
+        nullptr /* sandbox_ptr */);
+    }
+    else if_constexpr_named(cond4, detail::rlbox_is_sandbox_callback_v<T_Rhs>)
+    {
+      using T_RhsFunc = detail::rlbox_remove_wrapper_t<T_Rhs>;
+
+      // need to perform some typechecking to ensure we are assigning compatible
+      // function pointer types only
+      if_constexpr_named(subcond1, !std::is_assignable_v<T&, T_RhsFunc>)
+      {
+        rlbox_detail_static_fail_because(
+          subcond1,
+          "Trying to assign function pointer to field of incompatible types");
+      }
+      else
+      {
+        // Need to reinterpret_cast as the representation of the signature of a
+        // callback uses the machine model of the sandbox, while the field uses
+        // that of the application. But we have already checked above that this
+        // is safe.
+        auto func = val.get_raw_sandbox_value();
+        using T_Cast = std::remove_volatile_t<T_SandboxedType>;
+        get_sandbox_value_ref() = (T_Cast)func;
+      }
+    }
+    else if_constexpr_named(
+      cond5,
+      detail::is_fundamental_or_enum_v<T> ||
+        (std::is_array_v<T> && !std::is_pointer_v<T_Rhs_El>))
+    {
+      detail::convert_type_fundamental_or_array(get_sandbox_value_ref(), val);
+    }
+    else if_constexpr_named(
+      cond6, std::is_pointer_v<T_Rhs> || std::is_pointer_v<T_Rhs_El>)
+    {
+      rlbox_detail_static_fail_because(
+        cond6,
+        "Assignment of pointers is not safe as it could\n "
+        "1) Leak pointers from the appliction to the sandbox which may break "
+        "ASLR\n "
+        "2) Pass inaccessible pointers to the sandbox leading to crash\n "
+        "3) Break sandboxes that require pointers to be swizzled first\n "
+        "\n "
+        "Instead, if you want to pass in a pointer, do one of the following\n "
+        "1) Allocate with malloc_in_sandbox, and pass in a tainted pointer\n "
+        "2) For pointers that point to functions in the application, register "
+        "with sandbox.register_callback(\"foo\"), and pass in the registered "
+        "value\n "
+        "3) For pointers that point to functions in the sandbox, get the "
+        "address with get_sandbox_function_address(sandbox, foo), and pass in "
+        "the "
+        "address\n "
+        "4) For raw pointers, use assign_raw_pointer which performs required "
+        "safety checks\n ");
+    }
+    else
+    {
+      auto unknownCase =
+        !(cond1 || cond2 || cond3 || cond4 || cond5 /* || cond6 */);
+      rlbox_detail_static_fail_because(
+        unknownCase, "Assignment of the given type of value is not supported");
+    }
+
+    return *this;
+  }
+
+  template<typename T_Rhs>
+  void assign_raw_pointer(rlbox_sandbox<T_Sbx>& sandbox, T_Rhs val)
+  {
+    static_assert(std::is_pointer_v<T_Rhs>, "Must be a pointer");
+    static_assert(std::is_assignable_v<T&, T_Rhs>,
+                  "Should assign pointers of compatible types.");
+    // Maybe a function pointer, so we need to cast
+    const void* cast_val = reinterpret_cast<const void*>(val);
+    bool safe = sandbox.is_pointer_in_sandbox_memory(cast_val);
+    detail::dynamic_check(
+      safe,
+      "Tried to assign a pointer that is not in the sandbox.\n "
+      "This is not safe as it could\n "
+      "1) Leak pointers from the appliction to the sandbox which may break "
+      "ASLR\n "
+      "2) Pass inaccessible pointers to the sandbox leading to crash\n "
+      "3) Break sandboxes that require pointers to be swizzled first\n "
+      "\n "
+      "Instead, if you want to pass in a pointer, do one of the following\n "
+      "1) Allocate with malloc_in_sandbox, and pass in a tainted pointer\n "
+      "2) For pointers that point to functions in the application, register "
+      "with sandbox.register_callback(\"foo\"), and pass in the registered "
+      "value\n "
+      "3) For pointers that point to functions in the sandbox, get the "
+      "address with get_sandbox_function_address(sandbox, foo), and pass in "
+      "the "
+      "address\n ");
+    get_sandbox_value_ref() =
+      sandbox.template get_sandboxed_pointer<T_Rhs>(cast_val);
+  }
+
+  template<typename T_Dummy = void>
+  operator bool() const
+  {
+    rlbox_detail_static_fail_because(
+      detail::true_v<T_Dummy>,
+      "Cannot apply implicit conversion to bool on values that are located in "
+      "sandbox memory. This error occurs if you compare a dereferenced value "
+      "such as the code shown below\n\n"
+      "tainted<int**> a = ...;\n"
+      "assert(*a);\n\n"
+      "Instead you can write this code as \n"
+      "tainted<int*> temp = *a;\n"
+      "assert(temp);\n");
+    return false;
+  }
+};
+
+}