python模块介绍 hashlib

出自：http://blog.csdn.net/oychw/article/details/8921553

2013-05-13 磁针石

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9.1 hashlib

hashlib用来替换md5和sha模块，并使他们的API一致。它由OpenSSL支持，支持如下算法：md5,sha1, sha224, sha256, sha384, sha512.

9.1.1 示例数据

importhashlib

lorem = ’’’Loremipsum dolor sit amet, consectetur adipisicing elit,

sed doeiusmod tempor incididunt ut labore et dolore magna aliqua. Ut

enim ad minimveniam, quis nostrud exercitation ullamco laboris nisi

ut aliquip exea commodo consequat. Duis aute irure dolor in

reprehenderitin voluptate velit esse cillum dolore eu fugiat nulla

pariatur.Excepteur sint occaecat cupidatat non proident, sunt in

culpa quiofficia deserunt mollit anim id est laborum.’’’

9.1.2 MD5

importhashlib

fromhashlib_data import lorem

h =hashlib.md5()

h.update(lorem)

print h.hexdigest()

执行结果：

$ pythonhashlib_md5.py

1426f365574592350315090e295ac273

9.1.3 SHA1

importhashlib

fromhashlib_data import lorem

h =hashlib.sha1()

h.update(lorem)

printh.hexdigest()

执行结果：

$ pythonhashlib_sha1.py

8173396ba8a560b89a3f3e2fcc024b044bc83d0a

9.1.4 new

使用new可以指定加密的类型。

#end_pymotw_header

importhashlib

import sys

try:

hash_name = sys.argv[1]

exceptIndexError:

print 'Specify the hash name as the firstargument.'

else:

try:

data = sys.argv[2]

except IndexError:

from hashlib_data import lorem as data

h = hashlib.new(hash_name)

h.update(data)

printh.hexdigest()

执行结果：

$ pythonhashlib_new.py sha1

8173396ba8a560b89a3f3e2fcc024b044bc83d0a

$ pythonhashlib_new.py sha256

dca37495608c68ec23bbb54ab9675bf0152db63e5a51ab1061dc9982b843e767

$ pythonhashlib_new.py sha512

0e3d4bc1cbc117382fa077b147a7ff6363f6cbc7508877460f978a566a0adb6dbb4c8

b89f56514da98eb94d7135e1b7ad7fc4a2d747c02af67fcd4e571bd54de

$ pythonhashlib_new.py md5

1426f365574592350315090e295ac273

9.1.5 增量更新

文件太大的时候，可以分多次读入：

#end_pymotw_header

importhashlib

fromhashlib_data import lorem

h =hashlib.md5()

h.update(lorem)

all_at_once =h.hexdigest()

defchunkize(size, text):

"Return parts of the text insize-based increments."

start = 0

while start < len(text):

chunk = text[start:start+size]

yield chunk

start += size

return

h =hashlib.md5()

for chunk inchunkize(64, lorem):

h.update(chunk)

line_by_line= h.hexdigest()

print 'All atonce :', all_at_once

print 'Lineby line:', line_by_line

print'Same :', (all_at_once ==line_by_line)

执行结果：

$ pythonhashlib_update.py

All at once :1426f365574592350315090e295ac273

Line by line:1426f365574592350315090e295ac273

Same : True

参考资料：

hashlib(http://docs.python.org/library/hashlib.html) The standard librarydocumentation

for thismodule.

Voidspace:IronPython and hashlib

(www.voidspace.org.uk/python/weblog/arch_d7_2006_10_07.shtml#e497)A

wrapper for hashlibthat works with IronPython.

hmac (page473) The hmac module.

OpenSSL(http://www.openssl.org/) An open source encryption toolkit.

zlib包含adler32 和 crc32哈希。

手册中的示例：

>>> import hashlib

>>> m = hashlib.md5()

>>> m.update("Nobodyinspects")

>>> m.update("the spammish repetition")

>>> m.digest()

'\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9'

>>> m.digest_size

>>> m.block_size

>>> hashlib.sha224("Nobodyinspects the spammish repetition").hexdigest()

'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2'

属性hashlib.algorithms包含支持的算法。

属性hash.digest_size ：结果hash的大小

属性hash. block_size ： hash内部块的大小