sha
— SHA-1 消息摘要算法
¶
从 2.5 版起弃用：
使用
hashlib
模块代替。
This module implements the interface to NIST’s secure hash algorithm, known as SHA-1. SHA-1 is an improved version of the original SHA hash algorithm. It is used in the same way as the
md5
module: use
new()
to create an sha object, then feed this object with arbitrary strings using the
update()
method, and at any point you can ask it for the
digest
of the concatenation of the strings fed to it so far. SHA-1 digests are 160 bits instead of MD5’s 128 bits.
sha.
new
(
[
string
]
)
¶
返回新 SHA 对象。若
string
is present, the method call
update(string)
is made.
The following values are provided as constants in the module and as attributes of the sha objects returned by
new()
:
sha.
blocksize
¶
Size of the blocks fed into the hash function; this is always
1
. This size is used to allow an arbitrary string to be hashed.
sha.
digest_size
¶
The size of the resulting digest in bytes. This is always
20
.
SHA 对象拥有如 MD5 对象的相同方法：
sha.
update
(
arg
)
¶
Update the sha object with the string
arg
. Repeated calls are equivalent to a single call with the concatenation of all the arguments:
m.update(a);
m.update(b)
相当于
m.update(a+b)
.
sha.
digest
(
)
¶
Return the digest of the strings passed to the
update()
method so far. This is a 20-byte string which may contain non-ASCII characters, including null bytes.
sha.
hexdigest
(
)
¶
像
digest()
except the digest is returned as a string of length 40, containing only hexadecimal digits. This may be used to exchange the value safely in email or other non-binary environments.
sha.
copy
(
)
¶
Return a copy (“clone”) of the sha object. This can be used to efficiently compute the digests of strings that share a common initial substring.
另请参阅
安全哈希算法由 NIST 文档 FIPS PUB 180-2 定义： 安全哈希标准 , published in August 2002.
从 NIST 链接到有关安全哈希的各种信息。