Migrate AES-CCM to Rust (#10279)

src/cryptography/hazmat/backends/openssl/backend.py

@@ -11,7 +11,6 @@
 
 from cryptography import utils, x509
 from cryptography.exceptions import UnsupportedAlgorithm
-from cryptography.hazmat.backends.openssl import aead
 from cryptography.hazmat.backends.openssl.ciphers import _CipherContext
 from cryptography.hazmat.bindings._rust import openssl as rust_openssl
 from cryptography.hazmat.bindings.openssl import binding
@@ -561,9 +560,6 @@ def ed448_supported(self) -> bool:
             and not self._lib.CRYPTOGRAPHY_IS_BORINGSSL
         )
 
-    def aead_cipher_supported(self, cipher) -> bool:
-        return aead._aead_cipher_supported(self, cipher)
-
     def _zero_data(self, data, length: int) -> None:
         # We clear things this way because at the moment we're not
         # sure of a better way that can guarantee it overwrites the

src/cryptography/hazmat/bindings/_rust/openssl/aead.pyi

@@ -36,6 +36,23 @@ class ChaCha20Poly1305:
         associated_data: bytes | None,
     ) -> bytes: ...
 
+class AESCCM:
+    def __init__(self, key: bytes, tag_length: int = 16) -> None: ...
+    @staticmethod
+    def generate_key(key_size: int) -> bytes: ...
+    def encrypt(
+        self,
+        nonce: bytes,
+        data: bytes,
+        associated_data: bytes | None,
+    ) -> bytes: ...
+    def decrypt(
+        self,
+        nonce: bytes,
+        data: bytes,
+        associated_data: bytes | None,
+    ) -> bytes: ...
+
 class AESSIV:
     def __init__(self, key: bytes) -> None: ...
     @staticmethod