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Diffstat (limited to 'lib/Crypto/Hash/SHA384.py')
| -rw-r--r-- | lib/Crypto/Hash/SHA384.py | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/lib/Crypto/Hash/SHA384.py b/lib/Crypto/Hash/SHA384.py new file mode 100644 index 0000000..a98fa9a --- /dev/null +++ b/lib/Crypto/Hash/SHA384.py @@ -0,0 +1,186 @@ +# -*- 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) + +_raw_sha384_lib = load_pycryptodome_raw_lib("Crypto.Hash._SHA384", + """ + int SHA384_init(void **shaState); + int SHA384_destroy(void *shaState); + int SHA384_update(void *hs, + const uint8_t *buf, + size_t len); + int SHA384_digest(const void *shaState, + uint8_t *digest, + size_t digest_size); + int SHA384_copy(const void *src, void *dst); + + int SHA384_pbkdf2_hmac_assist(const void *inner, + const void *outer, + const uint8_t *first_digest, + uint8_t *final_digest, + size_t iterations, + size_t digest_size); + """) + +class SHA384Hash(object): + """A SHA-384 hash object. + Do not instantiate directly. Use the :func:`new` function. + + :ivar oid: ASN.1 Object ID + :vartype oid: string + + :ivar block_size: the size in bytes of the internal message block, + input to the compression function + :vartype block_size: integer + + :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 = 48 + # The internal block size of the hash algorithm in bytes. + block_size = 128 + # ASN.1 Object ID + oid = '2.16.840.1.101.3.4.2.2' + + def __init__(self, data=None): + state = VoidPointer() + result = _raw_sha384_lib.SHA384_init(state.address_of()) + if result: + raise ValueError("Error %d while instantiating SHA384" + % result) + self._state = SmartPointer(state.get(), + _raw_sha384_lib.SHA384_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. + """ + + result = _raw_sha384_lib.SHA384_update(self._state.get(), + c_uint8_ptr(data), + c_size_t(len(data))) + if result: + raise ValueError("Error %d while hashing data with SHA384" + % result) + + 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 + """ + + bfr = create_string_buffer(self.digest_size) + result = _raw_sha384_lib.SHA384_digest(self._state.get(), + bfr, + c_size_t(self.digest_size)) + if result: + raise ValueError("Error %d while making SHA384 digest" + % result) + + return get_raw_buffer(bfr) + + 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 = SHA384Hash() + result = _raw_sha384_lib.SHA384_copy(self._state.get(), + clone._state.get()) + if result: + raise ValueError("Error %d while copying SHA384" % result) + return clone + + def new(self, data=None): + """Create a fresh SHA-384 hash object.""" + + return SHA384Hash(data) + + +def new(data=None): + """Create a new hash object. + + :parameter data: + Optional. The very first chunk of the message to hash. + It is equivalent to an early call to :meth:`SHA384Hash.update`. + :type data: byte string/byte array/memoryview + + :Return: A :class:`SHA384Hash` hash object + """ + + return SHA384Hash().new(data) + + +# The size of the resulting hash in bytes. +digest_size = SHA384Hash.digest_size + +# The internal block size of the hash algorithm in bytes. +block_size = SHA384Hash.block_size + + +def _pbkdf2_hmac_assist(inner, outer, first_digest, iterations): + """Compute the expensive inner loop in PBKDF-HMAC.""" + + assert iterations > 0 + + bfr = create_string_buffer(len(first_digest)); + result = _raw_sha384_lib.SHA384_pbkdf2_hmac_assist( + inner._state.get(), + outer._state.get(), + first_digest, + bfr, + c_size_t(iterations), + c_size_t(len(first_digest))) + + if result: + raise ValueError("Error %d with PBKDF2-HMAC assist for SHA384" % result) + + return get_raw_buffer(bfr) |