Create SHA3_512.py

audit/SHA3_512.py

@@ -0,0 +1,172 @@
+# -*- coding: utf-8 -*-
+#
+# ===================================================================
+# The contents of this file are dedicated to the public domain.  To
+# the extent that dedication to the public domain is not available,
+# everyone is granted a worldwide, perpetual, royalty-free,
+# non-exclusive license to exercise all rights associated with the
+# contents of this file for any purpose whatsoever.
+# No rights are reserved.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+# ===================================================================
+
+from Crypto.Util.py3compat import bord
+
+from Crypto.Util._raw_api import (load_pycryptodome_raw_lib,
+                                  VoidPointer, SmartPointer,
+                                  create_string_buffer,
+                                  get_raw_buffer, c_size_t,
+                                  c_uint8_ptr)
+
+from Crypto.Hash.keccak import _raw_keccak_lib
+
+class SHA3_512_Hash(object):
+    """A SHA3-512 hash object.
+    Do not instantiate directly.
+    Use the :func:`new` function.
+
+    :ivar oid: ASN.1 Object ID
+    :vartype oid: string
+
+    :ivar digest_size: the size in bytes of the resulting hash
+    :vartype digest_size: integer
+    """
+
+    # The size of the resulting hash in bytes.
+    digest_size = 64
+
+    # ASN.1 Object ID
+    oid = "2.16.840.1.101.3.4.2.10"
+
+    # Input block size for HMAC
+    block_size = 72
+
+    def __init__(self, data, update_after_digest):
+        self._update_after_digest = update_after_digest
+        self._digest_done = False
+
+        state = VoidPointer()
+        result = _raw_keccak_lib.keccak_init(state.address_of(),
+                                             c_size_t(self.digest_size * 2),
+                                             0x06)
+        if result:
+            raise ValueError("Error %d while instantiating SHA-3/512"
+                             % result)
+        self._state = SmartPointer(state.get(),
+                                   _raw_keccak_lib.keccak_destroy)
+        if data:
+            self.update(data)
+
+    def update(self, data):
+        """Continue hashing of a message by consuming the next chunk of data.
+
+        Args:
+            data (byte string/byte array/memoryview): The next chunk of the message being hashed.
+        """
+
+        if self._digest_done and not self._update_after_digest:
+            raise TypeError("You can only call 'digest' or 'hexdigest' on this object")
+
+        result = _raw_keccak_lib.keccak_absorb(self._state.get(),
+                                               c_uint8_ptr(data),
+                                               c_size_t(len(data)))
+        if result:
+            raise ValueError("Error %d while updating SHA-3/512"
+                             % result)
+        return self
+
+    def digest(self):
+
+        """Return the **binary** (non-printable) digest of the message that has been hashed so far.
+
+        :return: The hash digest, computed over the data processed so far.
+                 Binary form.
+        :rtype: byte string
+        """
+
+        self._digest_done = True
+
+        bfr = create_string_buffer(self.digest_size)
+        result = _raw_keccak_lib.keccak_digest(self._state.get(),
+                                               bfr,
+                                               c_size_t(self.digest_size))
+        if result:
+            raise ValueError("Error %d while instantiating SHA-3/512"
+                             % result)
+
+        self._digest_value = get_raw_buffer(bfr)
+        return self._digest_value
+
+    def hexdigest(self):
+        """Return the **printable** digest of the message that has been hashed so far.
+
+        :return: The hash digest, computed over the data processed so far.
+                 Hexadecimal encoded.
+        :rtype: string
+        """
+
+        return "".join(["%02x" % bord(x) for x in self.digest()])
+
+    def copy(self):
+        """Return a copy ("clone") of the hash object.
+
+        The copy will have the same internal state as the original hash
+        object.
+        This can be used to efficiently compute the digests of strings that
+        share a common initial substring.
+
+        :return: A hash object of the same type
+        """
+
+        clone = self.new()
+        result = _raw_keccak_lib.keccak_copy(self._state.get(),
+                                             clone._state.get())
+        if result:
+            raise ValueError("Error %d while copying SHA3-512" % result)
+        return clone
+
+    def new(self, data=None):
+        """Create a fresh SHA3-521 hash object."""
+
+        return type(self)(data, self._update_after_digest)
+
+
+def new(*args, **kwargs):
+    """Create a new hash object.
+
+    Args:
+        data (byte string/byte array/memoryview):
+            The very first chunk of the message to hash.
+            It is equivalent to an early call to :meth:`update`.
+        update_after_digest (boolean):
+            Whether :meth:`digest` can be followed by another :meth:`update`
+            (default: ``False``).
+
+    :Return: A :class:`SHA3_512_Hash` hash object
+    """
+
+    data = kwargs.pop("data", None)
+    update_after_digest = kwargs.pop("update_after_digest", False)
+    if len(args) == 1:
+        if data:
+            raise ValueError("Initial data for hash specified twice")
+        data = args[0]
+
+    if kwargs:
+        raise TypeError("Unknown parameters: " + str(kwargs))
+
+    return SHA3_512_Hash(data, update_after_digest)
+
+# The size of the resulting hash in bytes.
+digest_size = SHA3_512_Hash.digest_size
+
+# Input block size for HMAC
+block_size = 72