moving to scripts

asq-env/lib/python3.9/site-packages/cryptography/hazmat/backends/openssl/hmac.py

@@ -0,0 +1,76 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+
+
+from cryptography.exceptions import (
+    InvalidSignature,
+    UnsupportedAlgorithm,
+    _Reasons,
+)
+from cryptography.hazmat.primitives import constant_time, hashes
+
+
+class _HMACContext(hashes.HashContext):
+    def __init__(
+        self, backend, key: bytes, algorithm: hashes.HashAlgorithm, ctx=None
+    ):
+        self._algorithm = algorithm
+        self._backend = backend
+
+        if ctx is None:
+            ctx = self._backend._lib.HMAC_CTX_new()
+            self._backend.openssl_assert(ctx != self._backend._ffi.NULL)
+            ctx = self._backend._ffi.gc(ctx, self._backend._lib.HMAC_CTX_free)
+            evp_md = self._backend._evp_md_from_algorithm(algorithm)
+            if evp_md == self._backend._ffi.NULL:
+                raise UnsupportedAlgorithm(
+                    "{} is not a supported hash on this backend".format(
+                        algorithm.name
+                    ),
+                    _Reasons.UNSUPPORTED_HASH,
+                )
+            key_ptr = self._backend._ffi.from_buffer(key)
+            res = self._backend._lib.HMAC_Init_ex(
+                ctx, key_ptr, len(key), evp_md, self._backend._ffi.NULL
+            )
+            self._backend.openssl_assert(res != 0)
+
+        self._ctx = ctx
+        self._key = key
+
+    @property
+    def algorithm(self) -> hashes.HashAlgorithm:
+        return self._algorithm
+
+    def copy(self) -> "_HMACContext":
+        copied_ctx = self._backend._lib.HMAC_CTX_new()
+        self._backend.openssl_assert(copied_ctx != self._backend._ffi.NULL)
+        copied_ctx = self._backend._ffi.gc(
+            copied_ctx, self._backend._lib.HMAC_CTX_free
+        )
+        res = self._backend._lib.HMAC_CTX_copy(copied_ctx, self._ctx)
+        self._backend.openssl_assert(res != 0)
+        return _HMACContext(
+            self._backend, self._key, self.algorithm, ctx=copied_ctx
+        )
+
+    def update(self, data: bytes) -> None:
+        data_ptr = self._backend._ffi.from_buffer(data)
+        res = self._backend._lib.HMAC_Update(self._ctx, data_ptr, len(data))
+        self._backend.openssl_assert(res != 0)
+
+    def finalize(self) -> bytes:
+        buf = self._backend._ffi.new(
+            "unsigned char[]", self._backend._lib.EVP_MAX_MD_SIZE
+        )
+        outlen = self._backend._ffi.new("unsigned int *")
+        res = self._backend._lib.HMAC_Final(self._ctx, buf, outlen)
+        self._backend.openssl_assert(res != 0)
+        self._backend.openssl_assert(outlen[0] == self.algorithm.digest_size)
+        return self._backend._ffi.buffer(buf)[: outlen[0]]
+
+    def verify(self, signature: bytes) -> None:
+        digest = self.finalize()
+        if not constant_time.bytes_eq(digest, signature):
+            raise InvalidSignature("Signature did not match digest.")