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author | Paul Kehrer <paul.l.kehrer@gmail.com> | 2017-01-05 14:11:17 -0500 |
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committer | Alex Gaynor <alex.gaynor@gmail.com> | 2017-01-05 14:11:17 -0500 |
commit | d74ba3298ddd4d3558224af85768e28f4c7f8d0d (patch) | |
tree | 82dcb0f34338310fa70163b5290f2ca1c775c5c2 /src | |
parent | 1c2458e0ceb1685b80dfe115a796926d3f1f4d86 (diff) | |
download | cryptography-d74ba3298ddd4d3558224af85768e28f4c7f8d0d.tar.gz cryptography-d74ba3298ddd4d3558224af85768e28f4c7f8d0d.tar.bz2 cryptography-d74ba3298ddd4d3558224af85768e28f4c7f8d0d.zip |
add memory limit check for scrypt (#3328)
* add memory limit check for scrypt
fixes #3323
* test a pass
* move _MEM_LIMIT to the scrypt module
Diffstat (limited to 'src')
-rw-r--r-- | src/cryptography/hazmat/backends/openssl/backend.py | 9 | ||||
-rw-r--r-- | src/cryptography/hazmat/primitives/kdf/scrypt.py | 7 |
2 files changed, 12 insertions, 4 deletions
diff --git a/src/cryptography/hazmat/backends/openssl/backend.py b/src/cryptography/hazmat/backends/openssl/backend.py index 76ecc08c..397a0210 100644 --- a/src/cryptography/hazmat/backends/openssl/backend.py +++ b/src/cryptography/hazmat/backends/openssl/backend.py @@ -9,7 +9,6 @@ import calendar import collections import contextlib import itertools -import sys from contextlib import contextmanager import six @@ -59,6 +58,7 @@ from cryptography.hazmat.primitives.ciphers.algorithms import ( from cryptography.hazmat.primitives.ciphers.modes import ( CBC, CFB, CFB8, CTR, ECB, GCM, OFB ) +from cryptography.hazmat.primitives.kdf import scrypt _MemoryBIO = collections.namedtuple("_MemoryBIO", ["bio", "char_ptr"]) @@ -1833,9 +1833,10 @@ class Backend(object): def derive_scrypt(self, key_material, salt, length, n, r, p): buf = self._ffi.new("unsigned char[]", length) - res = self._lib.EVP_PBE_scrypt(key_material, len(key_material), salt, - len(salt), n, r, p, sys.maxsize // 2, - buf, length) + res = self._lib.EVP_PBE_scrypt( + key_material, len(key_material), salt, len(salt), n, r, p, + scrypt._MEM_LIMIT, buf, length + ) self.openssl_assert(res == 1) return self._ffi.buffer(buf)[:] diff --git a/src/cryptography/hazmat/primitives/kdf/scrypt.py b/src/cryptography/hazmat/primitives/kdf/scrypt.py index 20935409..77dcf9ab 100644 --- a/src/cryptography/hazmat/primitives/kdf/scrypt.py +++ b/src/cryptography/hazmat/primitives/kdf/scrypt.py @@ -4,6 +4,8 @@ from __future__ import absolute_import, division, print_function +import sys + from cryptography import utils from cryptography.exceptions import ( AlreadyFinalized, InvalidKey, UnsupportedAlgorithm, _Reasons @@ -13,6 +15,11 @@ from cryptography.hazmat.primitives import constant_time from cryptography.hazmat.primitives.kdf import KeyDerivationFunction +# This is used by the scrypt tests to skip tests that require more memory +# than the MEM_LIMIT +_MEM_LIMIT = sys.maxsize // 2 + + @utils.register_interface(KeyDerivationFunction) class Scrypt(object): def __init__(self, salt, length, n, r, p, backend): |