diff --git a/modules/safe.py b/modules/safe.py
index ff5a4ca4..fe771c1b 100644
--- a/modules/safe.py
+++ b/modules/safe.py
@@ -1,39 +1,194 @@
+# this code is adapted from the script contributed by anon from /h/
+
+import pickle
+import collections
+
 import torch
-import contextlib
+import numpy
+import _codecs
+import zipfile
+import re
 
-TypedStorage = None
 
+# PyTorch 1.13 and later have _TypedStorage renamed to TypedStorage
+from modules import errors
+
+TypedStorage = torch.storage.TypedStorage if hasattr(torch.storage, 'TypedStorage') else torch.storage._TypedStorage
 
 def encode(*args):
-    pass
+    out = _codecs.encode(*args)
+    return out
 
 
-class RestrictedUnpickler:
-    pass
+class RestrictedUnpickler(pickle.Unpickler):
+    extra_handler = None
+
+    def persistent_load(self, saved_id):
+        assert saved_id[0] == 'storage'
+
+        try:
+            return TypedStorage(_internal=True)
+        except TypeError:
+            return TypedStorage()  # PyTorch before 2.0 does not have the _internal argument
+
+    def find_class(self, module, name):
+        if self.extra_handler is not None:
+            res = self.extra_handler(module, name)
+            if res is not None:
+                return res
+
+        if module == 'collections' and name == 'OrderedDict':
+            return getattr(collections, name)
+        if module == 'torch._utils' and name in ['_rebuild_tensor_v2', '_rebuild_parameter', '_rebuild_device_tensor_from_numpy']:
+            return getattr(torch._utils, name)
+        if module == 'torch' and name in ['FloatStorage', 'HalfStorage', 'IntStorage', 'LongStorage', 'DoubleStorage', 'ByteStorage', 'float32', 'BFloat16Storage']:
+            return getattr(torch, name)
+        if module == 'torch.nn.modules.container' and name in ['ParameterDict']:
+            return getattr(torch.nn.modules.container, name)
+        if module == 'numpy.core.multiarray' and name in ['scalar', '_reconstruct']:
+            return getattr(numpy.core.multiarray, name)
+        if module == 'numpy' and name in ['dtype', 'ndarray']:
+            return getattr(numpy, name)
+        if module == '_codecs' and name == 'encode':
+            return encode
+        if module == "pytorch_lightning.callbacks" and name == 'model_checkpoint':
+            import pytorch_lightning.callbacks
+            return pytorch_lightning.callbacks.model_checkpoint
+        if module == "pytorch_lightning.callbacks.model_checkpoint" and name == 'ModelCheckpoint':
+            import pytorch_lightning.callbacks.model_checkpoint
+            return pytorch_lightning.callbacks.model_checkpoint.ModelCheckpoint
+        if module == "__builtin__" and name == 'set':
+            return set
+
+        # Forbid everything else.
+        raise Exception(f"global '{module}/{name}' is forbidden")
 
 
-allowed_zip_names_re = None
-data_pkl_re = None
-
+# Regular expression that accepts 'dirname/version', 'dirname/data.pkl', and 'dirname/data/<number>'
+allowed_zip_names_re = re.compile(r"^([^/]+)/((data/\d+)|version|(data\.pkl))$")
+data_pkl_re = re.compile(r"^([^/]+)/data\.pkl$")
 
 def check_zip_filenames(filename, names):
-    pass
+    for name in names:
+        if allowed_zip_names_re.match(name):
+            continue
+
+        raise Exception(f"bad file inside {filename}: {name}")
 
 
 def check_pt(filename, extra_handler):
-    pass
+    try:
+
+        # new pytorch format is a zip file
+        with zipfile.ZipFile(filename) as z:
+            check_zip_filenames(filename, z.namelist())
+
+            # find filename of data.pkl in zip file: '<directory name>/data.pkl'
+            data_pkl_filenames = [f for f in z.namelist() if data_pkl_re.match(f)]
+            if len(data_pkl_filenames) == 0:
+                raise Exception(f"data.pkl not found in {filename}")
+            if len(data_pkl_filenames) > 1:
+                raise Exception(f"Multiple data.pkl found in {filename}")
+            with z.open(data_pkl_filenames[0]) as file:
+                unpickler = RestrictedUnpickler(file)
+                unpickler.extra_handler = extra_handler
+                unpickler.load()
+
+    except zipfile.BadZipfile:
+
+        # if it's not a zip file, it's an old pytorch format, with five objects written to pickle
+        with open(filename, "rb") as file:
+            unpickler = RestrictedUnpickler(file)
+            unpickler.extra_handler = extra_handler
+            for _ in range(5):
+                unpickler.load()
 
 
 def load(filename, *args, **kwargs):
-    pass
+    return load_with_extra(filename, *args, extra_handler=global_extra_handler, **kwargs)
 
 
 def load_with_extra(filename, extra_handler=None, *args, **kwargs):
-    pass
+    """
+    this function is intended to be used by extensions that want to load models with
+    some extra classes in them that the usual unpickler would find suspicious.
+
+    Use the extra_handler argument to specify a function that takes module and field name as text,
+    and returns that field's value:
+
+    ```python
+    def extra(module, name):
+        if module == 'collections' and name == 'OrderedDict':
+            return collections.OrderedDict
+
+        return None
+
+    safe.load_with_extra('model.pt', extra_handler=extra)
+    ```
+
+    The alternative to this is just to use safe.unsafe_torch_load('model.pt'), which as the name implies is
+    definitely unsafe.
+    """
+
+    from modules import shared
+
+    try:
+        if not shared.cmd_opts.disable_safe_unpickle:
+            check_pt(filename, extra_handler)
+
+    except pickle.UnpicklingError:
+        errors.report(
+            f"Error verifying pickled file from {filename}\n"
+            "-----> !!!! The file is most likely corrupted !!!! <-----\n"
+            "You can skip this check with --disable-safe-unpickle commandline argument, but that is not going to help you.\n\n",
+            exc_info=True,
+        )
+        return None
+    except Exception:
+        errors.report(
+            f"Error verifying pickled file from {filename}\n"
+            f"The file may be malicious, so the program is not going to read it.\n"
+            f"You can skip this check with --disable-safe-unpickle commandline argument.\n\n",
+            exc_info=True,
+        )
+        return None
+
+    return unsafe_torch_load(filename, *args, **kwargs)
 
 
-def Extra(*args, **kwargs):
-    return contextlib.nullcontext()
+class Extra:
+    """
+    A class for temporarily setting the global handler for when you can't explicitly call load_with_extra
+    (because it's not your code making the torch.load call). The intended use is like this:
+
+```
+import torch
+from modules import safe
+
+def handler(module, name):
+    if module == 'torch' and name in ['float64', 'float16']:
+        return getattr(torch, name)
+
+    return None
+
+with safe.Extra(handler):
+    x = torch.load('model.pt')
+```
+    """
+
+    def __init__(self, handler):
+        self.handler = handler
+
+    def __enter__(self):
+        global global_extra_handler
+
+        assert global_extra_handler is None, 'already inside an Extra() block'
+        global_extra_handler = self.handler
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        global global_extra_handler
+
+        global_extra_handler = None
 
 
 unsafe_torch_load = torch.load