晋太元中,武陵人捕鱼为业。缘溪行,忘路之远近。忽逢桃花林,夹岸数百步,中无杂树,芳草鲜美,落英缤纷。渔人甚异之,复前行,欲穷其林。 林尽水源,便得一山,山有小口,仿佛若有光。便舍船,从口入。初极狭,才通人。复行数十步,豁然开朗。土地平旷,屋舍俨然,有良田、美池、桑竹之属。阡陌交通,鸡犬相闻。其中往来种作,男女衣着,悉如外人。黄发垂髫,并怡然自乐。 见渔人,乃大惊,问所从来。具答之。便要还家,设酒杀鸡作食。村中闻有此人,咸来问讯。自云先世避秦时乱,率妻子邑人来此绝境,不复出焉,遂与外人间隔。问今是何世,乃不知有汉,无论魏晋。此人一一为具言所闻,皆叹惋。余人各复延至其家,皆出酒食。停数日,辞去。此中人语云:“不足为外人道也。”(间隔 一作:隔绝) 既出,得其船,便扶向路,处处志之。及郡下,诣太守,说如此。太守即遣人随其往,寻向所志,遂迷,不复得路。 南阳刘子骥,高尚士也,闻之,欣然规往。未果,寻病终。后遂无问津者。
|
Server : Apache System : Linux srv.rainic.com 4.18.0-553.47.1.el8_10.x86_64 #1 SMP Wed Apr 2 05:45:37 EDT 2025 x86_64 User : rainic ( 1014) PHP Version : 7.4.33 Disable Function : exec,passthru,shell_exec,system Directory : /lib64/python3.6/site-packages/cryptography/hazmat/backends/openssl/ |
Upload File : |
# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.
from __future__ import absolute_import, division, print_function
from cryptography import utils
from cryptography.exceptions import (
InvalidSignature,
UnsupportedAlgorithm,
_Reasons,
)
from cryptography.hazmat.primitives import constant_time, hashes, mac
@utils.register_interface(mac.MACContext)
@utils.register_interface(hashes.HashContext)
class _HMACContext(object):
def __init__(self, backend, key, algorithm, ctx=None):
self._algorithm = algorithm
self._backend = backend
if ctx is None:
ctx = self._backend._lib.Cryptography_HMAC_CTX_new()
self._backend.openssl_assert(ctx != self._backend._ffi.NULL)
ctx = self._backend._ffi.gc(
ctx, self._backend._lib.Cryptography_HMAC_CTX_free
)
evp_md = self._backend._evp_md_from_algorithm(algorithm)
if evp_md == self._backend._ffi.NULL:
raise UnsupportedAlgorithm(
"{} is not a supported hash on this backend".format(
algorithm.name
),
_Reasons.UNSUPPORTED_HASH,
)
key_ptr = self._backend._ffi.from_buffer(key)
res = self._backend._lib.HMAC_Init_ex(
ctx, key_ptr, len(key), evp_md, self._backend._ffi.NULL
)
self._backend.openssl_assert(res != 0)
self._ctx = ctx
self._key = key
algorithm = utils.read_only_property("_algorithm")
def copy(self):
copied_ctx = self._backend._lib.Cryptography_HMAC_CTX_new()
self._backend.openssl_assert(copied_ctx != self._backend._ffi.NULL)
copied_ctx = self._backend._ffi.gc(
copied_ctx, self._backend._lib.Cryptography_HMAC_CTX_free
)
res = self._backend._lib.HMAC_CTX_copy(copied_ctx, self._ctx)
self._backend.openssl_assert(res != 0)
return _HMACContext(
self._backend, self._key, self.algorithm, ctx=copied_ctx
)
def update(self, data):
data_ptr = self._backend._ffi.from_buffer(data)
res = self._backend._lib.HMAC_Update(self._ctx, data_ptr, len(data))
self._backend.openssl_assert(res != 0)
def finalize(self):
buf = self._backend._ffi.new(
"unsigned char[]", self._backend._lib.EVP_MAX_MD_SIZE
)
outlen = self._backend._ffi.new("unsigned int *")
res = self._backend._lib.HMAC_Final(self._ctx, buf, outlen)
self._backend.openssl_assert(res != 0)
self._backend.openssl_assert(outlen[0] == self.algorithm.digest_size)
return self._backend._ffi.buffer(buf)[: outlen[0]]
def verify(self, signature):
digest = self.finalize()
if not constant_time.bytes_eq(digest, signature):
raise InvalidSignature("Signature did not match digest.")