Fix handling very large pointer values (32-bit) (pyca#8602)

alex · web-flow · commit 0f0247198dec · 2023-03-25T00:51:14.000Z
diff --git a/src/cryptography/hazmat/backends/openssl/backend.py b/src/cryptography/hazmat/backends/openssl/backend.py
@@ -650,7 +650,7 @@ def _evp_pkey_to_private_key(
             return _X448PrivateKey(self, evp_pkey)
         elif key_type == self._lib.EVP_PKEY_X25519:
             return rust_openssl.x25519.private_key_from_ptr(
-                int(self._ffi.cast("intptr_t", evp_pkey))
+                int(self._ffi.cast("uintptr_t", evp_pkey))
             )
         elif key_type == getattr(self._lib, "EVP_PKEY_ED448", None):
             # EVP_PKEY_ED448 is not present in CRYPTOGRAPHY_IS_LIBRESSL
@@ -709,7 +709,7 @@ def _evp_pkey_to_public_key(self, evp_pkey) -> PublicKeyTypes:
             return _X448PublicKey(self, evp_pkey)
         elif key_type == self._lib.EVP_PKEY_X25519:
             return rust_openssl.x25519.public_key_from_ptr(
-                int(self._ffi.cast("intptr_t", evp_pkey))
+                int(self._ffi.cast("uintptr_t", evp_pkey))
             )
         elif key_type == getattr(self._lib, "EVP_PKEY_ED448", None):
             # EVP_PKEY_ED448 is not present in CRYPTOGRAPHY_IS_LIBRESSL
diff --git a/src/cryptography/utils.py b/src/cryptography/utils.py
@@ -46,7 +46,7 @@ def _extract_buffer_length(obj: typing.Any) -> typing.Tuple[int, int]:
     from cryptography.hazmat.bindings._rust import _openssl
 
     buf = _openssl.ffi.from_buffer(obj)
-    return int(_openssl.ffi.cast("intptr_t", buf)), len(buf)
+    return int(_openssl.ffi.cast("uintptr_t", buf)), len(buf)
 
 
 class InterfaceNotImplemented(Exception):
