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Diffstat (limited to '.venv/lib/python3.12/site-packages/nacl/pwhash/scrypt.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/nacl/pwhash/scrypt.py | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/nacl/pwhash/scrypt.py b/.venv/lib/python3.12/site-packages/nacl/pwhash/scrypt.py new file mode 100644 index 00000000..55bdf498 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/nacl/pwhash/scrypt.py @@ -0,0 +1,211 @@ +# Copyright 2013 Donald Stufft and individual contributors +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +from typing import cast + +import nacl.bindings +import nacl.encoding +from nacl import exceptions as exc +from nacl.exceptions import ensure + +_strbytes_plus_one = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_STRBYTES + +AVAILABLE = nacl.bindings.has_crypto_pwhash_scryptsalsa208sha256 + +STRPREFIX = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_STRPREFIX + +SALTBYTES = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_SALTBYTES + +PASSWD_MIN = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_PASSWD_MIN +PASSWD_MAX = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_PASSWD_MAX + +PWHASH_SIZE = _strbytes_plus_one - 1 + +BYTES_MIN = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_BYTES_MIN +BYTES_MAX = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_BYTES_MAX + +MEMLIMIT_MIN = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_MEMLIMIT_MIN +MEMLIMIT_MAX = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_MEMLIMIT_MAX +OPSLIMIT_MIN = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_OPSLIMIT_MIN +OPSLIMIT_MAX = nacl.bindings.crypto_pwhash_scryptsalsa208sha256_OPSLIMIT_MAX + +OPSLIMIT_INTERACTIVE = ( + nacl.bindings.crypto_pwhash_scryptsalsa208sha256_OPSLIMIT_INTERACTIVE +) +MEMLIMIT_INTERACTIVE = ( + nacl.bindings.crypto_pwhash_scryptsalsa208sha256_MEMLIMIT_INTERACTIVE +) +OPSLIMIT_SENSITIVE = ( + nacl.bindings.crypto_pwhash_scryptsalsa208sha256_OPSLIMIT_SENSITIVE +) +MEMLIMIT_SENSITIVE = ( + nacl.bindings.crypto_pwhash_scryptsalsa208sha256_MEMLIMIT_SENSITIVE +) + +OPSLIMIT_MODERATE = 8 * OPSLIMIT_INTERACTIVE +MEMLIMIT_MODERATE = 8 * MEMLIMIT_INTERACTIVE + + +def kdf( + size: int, + password: bytes, + salt: bytes, + opslimit: int = OPSLIMIT_SENSITIVE, + memlimit: int = MEMLIMIT_SENSITIVE, + encoder: nacl.encoding.Encoder = nacl.encoding.RawEncoder, +) -> bytes: + """ + Derive a ``size`` bytes long key from a caller-supplied + ``password`` and ``salt`` pair using the scryptsalsa208sha256 + memory-hard construct. + + + the enclosing module provides the constants + + - :py:const:`.OPSLIMIT_INTERACTIVE` + - :py:const:`.MEMLIMIT_INTERACTIVE` + - :py:const:`.OPSLIMIT_SENSITIVE` + - :py:const:`.MEMLIMIT_SENSITIVE` + - :py:const:`.OPSLIMIT_MODERATE` + - :py:const:`.MEMLIMIT_MODERATE` + + as a guidance for correct settings respectively for the + interactive login and the long term key protecting sensitive data + use cases. + + :param size: derived key size, must be between + :py:const:`.BYTES_MIN` and + :py:const:`.BYTES_MAX` + :type size: int + :param password: password used to seed the key derivation procedure; + it length must be between + :py:const:`.PASSWD_MIN` and + :py:const:`.PASSWD_MAX` + :type password: bytes + :param salt: **RANDOM** salt used in the key derivation procedure; + its length must be exactly :py:const:`.SALTBYTES` + :type salt: bytes + :param opslimit: the time component (operation count) + of the key derivation procedure's computational cost; + it must be between + :py:const:`.OPSLIMIT_MIN` and + :py:const:`.OPSLIMIT_MAX` + :type opslimit: int + :param memlimit: the memory occupation component + of the key derivation procedure's computational cost; + it must be between + :py:const:`.MEMLIMIT_MIN` and + :py:const:`.MEMLIMIT_MAX` + :type memlimit: int + :rtype: bytes + :raises nacl.exceptions.UnavailableError: If called when using a + minimal build of libsodium. + + .. versionadded:: 1.2 + """ + ensure( + AVAILABLE, + "Not available in minimal build", + raising=exc.UnavailableError, + ) + + ensure( + len(salt) == SALTBYTES, + "The salt must be exactly %s, not %s bytes long" + % (SALTBYTES, len(salt)), + raising=exc.ValueError, + ) + + n_log2, r, p = nacl.bindings.nacl_bindings_pick_scrypt_params( + opslimit, memlimit + ) + maxmem = memlimit + (2 ** 16) + + return encoder.encode( + nacl.bindings.crypto_pwhash_scryptsalsa208sha256_ll( + password, + salt, + # Cast safety: n_log2 is a positive integer, and so 2 ** n_log2 is also + # a positive integer. Mypy+typeshed can't deduce this, because there's no + # way to for them to know that n_log2: int is positive. + cast(int, 2 ** n_log2), + r, + p, + maxmem=maxmem, + dklen=size, + ) + ) + + +def str( + password: bytes, + opslimit: int = OPSLIMIT_INTERACTIVE, + memlimit: int = MEMLIMIT_INTERACTIVE, +) -> bytes: + """ + Hashes a password with a random salt, using the memory-hard + scryptsalsa208sha256 construct and returning an ascii string + that has all the needed info to check against a future password + + The default settings for opslimit and memlimit are those deemed + correct for the interactive user login case. + + :param bytes password: + :param int opslimit: + :param int memlimit: + :rtype: bytes + :raises nacl.exceptions.UnavailableError: If called when using a + minimal build of libsodium. + + .. versionadded:: 1.2 + """ + ensure( + AVAILABLE, + "Not available in minimal build", + raising=exc.UnavailableError, + ) + + return nacl.bindings.crypto_pwhash_scryptsalsa208sha256_str( + password, opslimit, memlimit + ) + + +def verify(password_hash: bytes, password: bytes) -> bool: + """ + Takes the output of scryptsalsa208sha256 and compares it against + a user provided password to see if they are the same + + :param password_hash: bytes + :param password: bytes + :rtype: boolean + :raises nacl.exceptions.UnavailableError: If called when using a + minimal build of libsodium. + + .. versionadded:: 1.2 + """ + ensure( + AVAILABLE, + "Not available in minimal build", + raising=exc.UnavailableError, + ) + + ensure( + len(password_hash) == PWHASH_SIZE, + "The password hash must be exactly %s bytes long" + % nacl.bindings.crypto_pwhash_scryptsalsa208sha256_STRBYTES, + raising=exc.ValueError, + ) + + return nacl.bindings.crypto_pwhash_scryptsalsa208sha256_str_verify( + password_hash, password + ) |