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486 lines
17 KiB
Python
486 lines
17 KiB
Python
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# Copyright 2017 Donald Stufft and individual contributors
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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from __future__ import absolute_import, division, print_function
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from nacl import exceptions as exc
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from nacl._sodium import ffi, lib
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from nacl.exceptions import ensure
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"""
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Implementations of authenticated encription with associated data (*AEAD*)
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constructions building on the chacha20 stream cipher and the poly1305
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authenticator
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"""
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crypto_aead_chacha20poly1305_ietf_KEYBYTES = \
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lib.crypto_aead_chacha20poly1305_ietf_keybytes()
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crypto_aead_chacha20poly1305_ietf_NSECBYTES = \
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lib.crypto_aead_chacha20poly1305_ietf_nsecbytes()
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crypto_aead_chacha20poly1305_ietf_NPUBBYTES = \
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lib.crypto_aead_chacha20poly1305_ietf_npubbytes()
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crypto_aead_chacha20poly1305_ietf_ABYTES = \
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lib.crypto_aead_chacha20poly1305_ietf_abytes()
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crypto_aead_chacha20poly1305_ietf_MESSAGEBYTES_MAX = \
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lib.crypto_aead_chacha20poly1305_ietf_messagebytes_max()
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_aead_chacha20poly1305_ietf_CRYPTBYTES_MAX = \
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crypto_aead_chacha20poly1305_ietf_MESSAGEBYTES_MAX + \
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crypto_aead_chacha20poly1305_ietf_ABYTES
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crypto_aead_chacha20poly1305_KEYBYTES = \
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lib.crypto_aead_chacha20poly1305_keybytes()
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crypto_aead_chacha20poly1305_NSECBYTES = \
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lib.crypto_aead_chacha20poly1305_nsecbytes()
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crypto_aead_chacha20poly1305_NPUBBYTES = \
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lib.crypto_aead_chacha20poly1305_npubbytes()
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crypto_aead_chacha20poly1305_ABYTES = \
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lib.crypto_aead_chacha20poly1305_abytes()
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crypto_aead_chacha20poly1305_MESSAGEBYTES_MAX = \
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lib.crypto_aead_chacha20poly1305_messagebytes_max()
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_aead_chacha20poly1305_CRYPTBYTES_MAX = \
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crypto_aead_chacha20poly1305_MESSAGEBYTES_MAX + \
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crypto_aead_chacha20poly1305_ABYTES
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crypto_aead_xchacha20poly1305_ietf_KEYBYTES = \
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lib.crypto_aead_xchacha20poly1305_ietf_keybytes()
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crypto_aead_xchacha20poly1305_ietf_NSECBYTES = \
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lib.crypto_aead_xchacha20poly1305_ietf_nsecbytes()
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crypto_aead_xchacha20poly1305_ietf_NPUBBYTES = \
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lib.crypto_aead_xchacha20poly1305_ietf_npubbytes()
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crypto_aead_xchacha20poly1305_ietf_ABYTES = \
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lib.crypto_aead_xchacha20poly1305_ietf_abytes()
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crypto_aead_xchacha20poly1305_ietf_MESSAGEBYTES_MAX = \
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lib.crypto_aead_xchacha20poly1305_ietf_messagebytes_max()
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_aead_xchacha20poly1305_ietf_CRYPTBYTES_MAX = \
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crypto_aead_xchacha20poly1305_ietf_MESSAGEBYTES_MAX + \
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crypto_aead_xchacha20poly1305_ietf_ABYTES
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def crypto_aead_chacha20poly1305_ietf_encrypt(message, aad, nonce, key):
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"""
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Encrypt the given ``message`` using the IETF ratified chacha20poly1305
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construction described in RFC7539.
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:param message:
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:type message: bytes
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:param aad:
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:type aad: bytes
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:param nonce:
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:type nonce: bytes
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:param key:
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:type key: bytes
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:return: authenticated ciphertext
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:rtype: bytes
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"""
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ensure(isinstance(message, bytes), 'Input message type must be bytes',
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raising=exc.TypeError)
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mlen = len(message)
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ensure(mlen <= crypto_aead_chacha20poly1305_ietf_MESSAGEBYTES_MAX,
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'Message must be at most {0} bytes long'.format(
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crypto_aead_chacha20poly1305_ietf_MESSAGEBYTES_MAX),
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raising=exc.ValueError)
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ensure(isinstance(aad, bytes) or (aad is None),
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'Additional data must be bytes or None',
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raising=exc.TypeError)
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ensure(isinstance(nonce, bytes) and
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len(nonce) == crypto_aead_chacha20poly1305_ietf_NPUBBYTES,
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'Nonce must be a {0} bytes long bytes sequence'.format(
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crypto_aead_chacha20poly1305_ietf_NPUBBYTES),
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raising=exc.TypeError)
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ensure(isinstance(key, bytes) and
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len(key) == crypto_aead_chacha20poly1305_ietf_KEYBYTES,
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'Key must be a {0} bytes long bytes sequence'.format(
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crypto_aead_chacha20poly1305_ietf_KEYBYTES),
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raising=exc.TypeError)
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if aad:
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_aad = aad
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aalen = len(aad)
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else:
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_aad = ffi.NULL
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aalen = 0
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mxout = mlen + crypto_aead_chacha20poly1305_ietf_ABYTES
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clen = ffi.new("unsigned long long *")
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ciphertext = ffi.new("unsigned char[]", mxout)
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res = lib.crypto_aead_chacha20poly1305_ietf_encrypt(ciphertext,
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clen,
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message,
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mlen,
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_aad,
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aalen,
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ffi.NULL,
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nonce,
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key)
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ensure(res == 0, "Encryption failed.", raising=exc.CryptoError)
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return ffi.buffer(ciphertext, clen[0])[:]
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def crypto_aead_chacha20poly1305_ietf_decrypt(ciphertext, aad, nonce, key):
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"""
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Decrypt the given ``ciphertext`` using the IETF ratified chacha20poly1305
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construction described in RFC7539.
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:param ciphertext:
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:type ciphertext: bytes
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:param aad:
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:type aad: bytes
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:param nonce:
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:type nonce: bytes
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:param key:
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:type key: bytes
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:return: message
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:rtype: bytes
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"""
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ensure(isinstance(ciphertext, bytes),
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'Input ciphertext type must be bytes',
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raising=exc.TypeError)
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clen = len(ciphertext)
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ensure(clen <= _aead_chacha20poly1305_ietf_CRYPTBYTES_MAX,
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'Ciphertext must be at most {0} bytes long'.format(
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_aead_chacha20poly1305_ietf_CRYPTBYTES_MAX),
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raising=exc.ValueError)
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ensure(isinstance(aad, bytes) or (aad is None),
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'Additional data must be bytes or None',
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raising=exc.TypeError)
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ensure(isinstance(nonce, bytes) and
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len(nonce) == crypto_aead_chacha20poly1305_ietf_NPUBBYTES,
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'Nonce must be a {0} bytes long bytes sequence'.format(
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crypto_aead_chacha20poly1305_ietf_NPUBBYTES),
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raising=exc.TypeError)
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ensure(isinstance(key, bytes) and
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len(key) == crypto_aead_chacha20poly1305_ietf_KEYBYTES,
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'Key must be a {0} bytes long bytes sequence'.format(
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crypto_aead_chacha20poly1305_ietf_KEYBYTES),
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raising=exc.TypeError)
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mxout = clen - crypto_aead_chacha20poly1305_ietf_ABYTES
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mlen = ffi.new("unsigned long long *")
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message = ffi.new("unsigned char[]", mxout)
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if aad:
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_aad = aad
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aalen = len(aad)
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else:
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_aad = ffi.NULL
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aalen = 0
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res = lib.crypto_aead_chacha20poly1305_ietf_decrypt(message,
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mlen,
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ffi.NULL,
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ciphertext,
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clen,
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_aad,
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aalen,
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nonce,
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key)
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ensure(res == 0, "Decryption failed.", raising=exc.CryptoError)
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return ffi.buffer(message, mlen[0])[:]
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def crypto_aead_chacha20poly1305_encrypt(message, aad, nonce, key):
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"""
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Encrypt the given ``message`` using the "legacy" construction
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described in draft-agl-tls-chacha20poly1305.
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:param message:
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:type message: bytes
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:param aad:
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:type aad: bytes
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:param nonce:
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:type nonce: bytes
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:param key:
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:type key: bytes
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:return: authenticated ciphertext
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:rtype: bytes
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"""
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ensure(isinstance(message, bytes), 'Input message type must be bytes',
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raising=exc.TypeError)
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mlen = len(message)
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ensure(mlen <= crypto_aead_chacha20poly1305_MESSAGEBYTES_MAX,
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'Message must be at most {0} bytes long'.format(
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crypto_aead_chacha20poly1305_MESSAGEBYTES_MAX),
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raising=exc.ValueError)
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ensure(isinstance(aad, bytes) or (aad is None),
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'Additional data must be bytes or None',
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raising=exc.TypeError)
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ensure(isinstance(nonce, bytes) and
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len(nonce) == crypto_aead_chacha20poly1305_NPUBBYTES,
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'Nonce must be a {0} bytes long bytes sequence'.format(
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crypto_aead_chacha20poly1305_NPUBBYTES),
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raising=exc.TypeError)
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ensure(isinstance(key, bytes) and
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len(key) == crypto_aead_chacha20poly1305_KEYBYTES,
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'Key must be a {0} bytes long bytes sequence'.format(
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crypto_aead_chacha20poly1305_KEYBYTES),
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raising=exc.TypeError)
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if aad:
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_aad = aad
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aalen = len(aad)
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else:
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_aad = ffi.NULL
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aalen = 0
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mlen = len(message)
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mxout = mlen + crypto_aead_chacha20poly1305_ietf_ABYTES
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clen = ffi.new("unsigned long long *")
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ciphertext = ffi.new("unsigned char[]", mxout)
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res = lib.crypto_aead_chacha20poly1305_encrypt(ciphertext,
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clen,
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message,
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mlen,
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_aad,
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aalen,
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ffi.NULL,
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nonce,
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key)
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ensure(res == 0, "Encryption failed.", raising=exc.CryptoError)
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return ffi.buffer(ciphertext, clen[0])[:]
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def crypto_aead_chacha20poly1305_decrypt(ciphertext, aad, nonce, key):
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"""
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Decrypt the given ``ciphertext`` using the "legacy" construction
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described in draft-agl-tls-chacha20poly1305.
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:param ciphertext: authenticated ciphertext
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:type ciphertext: bytes
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:param aad:
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:type aad: bytes
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:param nonce:
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:type nonce: bytes
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:param key:
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:type key: bytes
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:return: message
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:rtype: bytes
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"""
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ensure(isinstance(ciphertext, bytes),
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'Input ciphertext type must be bytes',
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raising=exc.TypeError)
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clen = len(ciphertext)
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ensure(clen <= _aead_chacha20poly1305_CRYPTBYTES_MAX,
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'Ciphertext must be at most {0} bytes long'.format(
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_aead_chacha20poly1305_CRYPTBYTES_MAX),
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raising=exc.ValueError)
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ensure(isinstance(aad, bytes) or (aad is None),
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'Additional data must be bytes or None',
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raising=exc.TypeError)
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ensure(isinstance(nonce, bytes) and
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len(nonce) == crypto_aead_chacha20poly1305_NPUBBYTES,
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'Nonce must be a {0} bytes long bytes sequence'.format(
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crypto_aead_chacha20poly1305_NPUBBYTES),
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raising=exc.TypeError)
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ensure(isinstance(key, bytes) and
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len(key) == crypto_aead_chacha20poly1305_KEYBYTES,
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'Key must be a {0} bytes long bytes sequence'.format(
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crypto_aead_chacha20poly1305_KEYBYTES),
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raising=exc.TypeError)
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mxout = clen - crypto_aead_chacha20poly1305_ABYTES
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mlen = ffi.new("unsigned long long *")
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message = ffi.new("unsigned char[]", mxout)
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if aad:
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_aad = aad
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aalen = len(aad)
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else:
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_aad = ffi.NULL
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aalen = 0
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res = lib.crypto_aead_chacha20poly1305_decrypt(message,
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mlen,
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ffi.NULL,
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ciphertext,
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clen,
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_aad,
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aalen,
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nonce,
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key)
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ensure(res == 0, "Decryption failed.", raising=exc.CryptoError)
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return ffi.buffer(message, mlen[0])[:]
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def crypto_aead_xchacha20poly1305_ietf_encrypt(message, aad, nonce, key):
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"""
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Encrypt the given ``message`` using the long-nonces xchacha20poly1305
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construction.
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:param message:
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:type message: bytes
|
||
|
|
:param aad:
|
||
|
|
:type aad: bytes
|
||
|
|
:param nonce:
|
||
|
|
:type nonce: bytes
|
||
|
|
:param key:
|
||
|
|
:type key: bytes
|
||
|
|
:return: authenticated ciphertext
|
||
|
|
:rtype: bytes
|
||
|
|
"""
|
||
|
|
ensure(isinstance(message, bytes), 'Input message type must be bytes',
|
||
|
|
raising=exc.TypeError)
|
||
|
|
|
||
|
|
mlen = len(message)
|
||
|
|
|
||
|
|
ensure(mlen <= crypto_aead_xchacha20poly1305_ietf_MESSAGEBYTES_MAX,
|
||
|
|
'Message must be at most {0} bytes long'.format(
|
||
|
|
crypto_aead_xchacha20poly1305_ietf_MESSAGEBYTES_MAX),
|
||
|
|
raising=exc.ValueError)
|
||
|
|
|
||
|
|
ensure(isinstance(aad, bytes) or (aad is None),
|
||
|
|
'Additional data must be bytes or None',
|
||
|
|
raising=exc.TypeError)
|
||
|
|
|
||
|
|
ensure(isinstance(nonce, bytes) and
|
||
|
|
len(nonce) == crypto_aead_xchacha20poly1305_ietf_NPUBBYTES,
|
||
|
|
'Nonce must be a {0} bytes long bytes sequence'.format(
|
||
|
|
crypto_aead_xchacha20poly1305_ietf_NPUBBYTES),
|
||
|
|
raising=exc.TypeError)
|
||
|
|
|
||
|
|
ensure(isinstance(key, bytes) and
|
||
|
|
len(key) == crypto_aead_xchacha20poly1305_ietf_KEYBYTES,
|
||
|
|
'Key must be a {0} bytes long bytes sequence'.format(
|
||
|
|
crypto_aead_xchacha20poly1305_ietf_KEYBYTES),
|
||
|
|
raising=exc.TypeError)
|
||
|
|
|
||
|
|
if aad:
|
||
|
|
_aad = aad
|
||
|
|
aalen = len(aad)
|
||
|
|
else:
|
||
|
|
_aad = ffi.NULL
|
||
|
|
aalen = 0
|
||
|
|
|
||
|
|
mlen = len(message)
|
||
|
|
mxout = mlen + crypto_aead_xchacha20poly1305_ietf_ABYTES
|
||
|
|
|
||
|
|
clen = ffi.new("unsigned long long *")
|
||
|
|
|
||
|
|
ciphertext = ffi.new("unsigned char[]", mxout)
|
||
|
|
|
||
|
|
res = lib.crypto_aead_xchacha20poly1305_ietf_encrypt(ciphertext,
|
||
|
|
clen,
|
||
|
|
message,
|
||
|
|
mlen,
|
||
|
|
_aad,
|
||
|
|
aalen,
|
||
|
|
ffi.NULL,
|
||
|
|
nonce,
|
||
|
|
key)
|
||
|
|
|
||
|
|
ensure(res == 0, "Encryption failed.", raising=exc.CryptoError)
|
||
|
|
return ffi.buffer(ciphertext, clen[0])[:]
|
||
|
|
|
||
|
|
|
||
|
|
def crypto_aead_xchacha20poly1305_ietf_decrypt(ciphertext, aad, nonce, key):
|
||
|
|
"""
|
||
|
|
Decrypt the given ``ciphertext`` using the long-nonces xchacha20poly1305
|
||
|
|
construction.
|
||
|
|
|
||
|
|
:param ciphertext: authenticated ciphertext
|
||
|
|
:type ciphertext: bytes
|
||
|
|
:param aad:
|
||
|
|
:type aad: bytes
|
||
|
|
:param nonce:
|
||
|
|
:type nonce: bytes
|
||
|
|
:param key:
|
||
|
|
:type key: bytes
|
||
|
|
:return: message
|
||
|
|
:rtype: bytes
|
||
|
|
"""
|
||
|
|
ensure(isinstance(ciphertext, bytes),
|
||
|
|
'Input ciphertext type must be bytes',
|
||
|
|
raising=exc.TypeError)
|
||
|
|
|
||
|
|
clen = len(ciphertext)
|
||
|
|
|
||
|
|
ensure(clen <= _aead_xchacha20poly1305_ietf_CRYPTBYTES_MAX,
|
||
|
|
'Ciphertext must be at most {0} bytes long'.format(
|
||
|
|
_aead_xchacha20poly1305_ietf_CRYPTBYTES_MAX),
|
||
|
|
raising=exc.ValueError)
|
||
|
|
|
||
|
|
ensure(isinstance(aad, bytes) or (aad is None),
|
||
|
|
'Additional data must be bytes or None',
|
||
|
|
raising=exc.TypeError)
|
||
|
|
|
||
|
|
ensure(isinstance(nonce, bytes) and
|
||
|
|
len(nonce) == crypto_aead_xchacha20poly1305_ietf_NPUBBYTES,
|
||
|
|
'Nonce must be a {0} bytes long bytes sequence'.format(
|
||
|
|
crypto_aead_xchacha20poly1305_ietf_NPUBBYTES),
|
||
|
|
raising=exc.TypeError)
|
||
|
|
|
||
|
|
ensure(isinstance(key, bytes) and
|
||
|
|
len(key) == crypto_aead_xchacha20poly1305_ietf_KEYBYTES,
|
||
|
|
'Key must be a {0} bytes long bytes sequence'.format(
|
||
|
|
crypto_aead_xchacha20poly1305_ietf_KEYBYTES),
|
||
|
|
raising=exc.TypeError)
|
||
|
|
|
||
|
|
mxout = clen - crypto_aead_xchacha20poly1305_ietf_ABYTES
|
||
|
|
mlen = ffi.new("unsigned long long *")
|
||
|
|
message = ffi.new("unsigned char[]", mxout)
|
||
|
|
|
||
|
|
if aad:
|
||
|
|
_aad = aad
|
||
|
|
aalen = len(aad)
|
||
|
|
else:
|
||
|
|
_aad = ffi.NULL
|
||
|
|
aalen = 0
|
||
|
|
|
||
|
|
res = lib.crypto_aead_xchacha20poly1305_ietf_decrypt(message,
|
||
|
|
mlen,
|
||
|
|
ffi.NULL,
|
||
|
|
ciphertext,
|
||
|
|
clen,
|
||
|
|
_aad,
|
||
|
|
aalen,
|
||
|
|
nonce,
|
||
|
|
key)
|
||
|
|
|
||
|
|
ensure(res == 0, "Decryption failed.", raising=exc.CryptoError)
|
||
|
|
|
||
|
|
return ffi.buffer(message, mlen[0])[:]
|