Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/cryptography/hazmat/backends/openssl/hashes.py

@@ -0,0 +1,82 @@
+# 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 __future__ import absolute_import, division, print_function
+
+
+from cryptography import utils
+from cryptography.exceptions import UnsupportedAlgorithm, _Reasons
+from cryptography.hazmat.primitives import hashes
+
+
+@utils.register_interface(hashes.HashContext)
+class _HashContext(object):
+    def __init__(self, backend, algorithm, ctx=None):
+        self._algorithm = algorithm
+
+        self._backend = backend
+
+        if ctx is None:
+            ctx = self._backend._lib.Cryptography_EVP_MD_CTX_new()
+            ctx = self._backend._ffi.gc(
+                ctx, self._backend._lib.Cryptography_EVP_MD_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,
+                )
+            res = self._backend._lib.EVP_DigestInit_ex(
+                ctx, evp_md, self._backend._ffi.NULL
+            )
+            self._backend.openssl_assert(res != 0)
+
+        self._ctx = ctx
+
+    algorithm = utils.read_only_property("_algorithm")
+
+    def copy(self):
+        copied_ctx = self._backend._lib.Cryptography_EVP_MD_CTX_new()
+        copied_ctx = self._backend._ffi.gc(
+            copied_ctx, self._backend._lib.Cryptography_EVP_MD_CTX_free
+        )
+        res = self._backend._lib.EVP_MD_CTX_copy_ex(copied_ctx, self._ctx)
+        self._backend.openssl_assert(res != 0)
+        return _HashContext(self._backend, self.algorithm, ctx=copied_ctx)
+
+    def update(self, data):
+        data_ptr = self._backend._ffi.from_buffer(data)
+        res = self._backend._lib.EVP_DigestUpdate(
+            self._ctx, data_ptr, len(data)
+        )
+        self._backend.openssl_assert(res != 0)
+
+    def finalize(self):
+        if isinstance(self.algorithm, hashes.ExtendableOutputFunction):
+            # extendable output functions use a different finalize
+            return self._finalize_xof()
+        else:
+            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.EVP_DigestFinal_ex(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 _finalize_xof(self):
+        buf = self._backend._ffi.new(
+            "unsigned char[]", self.algorithm.digest_size
+        )
+        res = self._backend._lib.EVP_DigestFinalXOF(
+            self._ctx, buf, self.algorithm.digest_size
+        )
+        self._backend.openssl_assert(res != 0)
+        return self._backend._ffi.buffer(buf)[: self.algorithm.digest_size]