这篇文章主要介绍了经典PHP加密解密函数Authcode()修复版代码,需要的朋友可以参考下
Authcode这个函数很多人都使用，这函数来自Discuz程序，用于加密解密字符串，可以设置钥匙（key）和过期时间，在很多时候都用得着。原版的函数代码可能会生成+、/、&这样的字符，导致通过URL传值取回时被转义，导致无法解密。火端网络稍加修改，把这几个字符替换成其它字符，解密时再替换回去，这样就完美了！
代码如下：
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function
authcode(
$string
,
$operation
=
'DECODE'
,
$key
=
''
,
$expiry
= 0){
if
(
$operation
==
'DECODE'
) {
$string
=
str_replace
(
'[a]'
,
'+'
,
$string
);
$string
=
str_replace
(
'[b]'
,
'&'
,
$string
);
$string
=
str_replace
(
'[c]'
,
'/'
,
$string
);
}
$ckey_length
= 4;
$key
= md5(
$key
?
$key
:
'livcmsencryption '
);
$keya
= md5(
substr
(
$key
, 0, 16));
$keyb
= md5(
substr
(
$key
, 16, 16));
$keyc
=
$ckey_length
? (
$operation
==
'DECODE'
?
substr
(
$string
, 0,
$ckey_length
):
substr
(md5(microtime()), -
$ckey_length
)) :
''
;
$cryptkey
=
$keya
.md5(
$keya
.
$keyc
);
$key_length
=
strlen
(
$cryptkey
);
$string
=
$operation
==
'DECODE'
?
base64_decode
(
substr
(
$string
,
$ckey_length
)) : sprintf(
'%010d'
,
$expiry
?
$expiry
+ time() : 0).
substr
(md5(
$string
.
$keyb
), 0, 16).
$string
;
$string_length
=
strlen
(
$string
);
$result
=
''
;
$box
= range(0, 255);
$rndkey
=
array
();
for
(
$i
= 0;
$i
<= 255;
$i
++) {
$rndkey
[
$i
] = ord(
$cryptkey
[
$i
%
$key_length
]);
}
for
(
$j
=
$i
= 0;
$i
< 256;
$i
++) {
$j
= (
$j
+
$box
[
$i
] +
$rndkey
[
$i
]) % 256;
$tmp
=
$box
[
$i
];
$box
[
$i
] =
$box
[
$j
];
$box
[
$j
] =
$tmp
;
}
for
(
$a
=
$j
=
$i
= 0;
$i
<
$string_length
;
$i
++) {
$a
= (
$a
+ 1) % 256;
$j
= (
$j
+
$box
[
$a
]) % 256;
$tmp
=
$box
[
$a
];
$box
[
$a
] =
$box
[
$j
];
$box
[
$j
] =
$tmp
;
$result
.=
chr
(ord(
$string
[
$i
]) ^ (
$box
[(
$box
[
$a
] +
$box
[
$j
]) % 256]));
}
if
(
$operation
==
'DECODE'
) {
if
((
substr
(
$result
, 0, 10) == 0 ||
substr
(
$result
, 0, 10) - time() > 0) &&
substr
(
$result
, 10, 16) ==
substr
(md5(
substr
(
$result
, 26).
$keyb
), 0, 16)) {
return
substr
(
$result
, 26);
}
else
{
return
''
;
}
}
else
{
$ustr
=
$keyc
.
str_replace
(
'='
,
''
,
base64_encode
(
$result
));
$ustr
=
str_replace
(
'+'
,
'[a]'
,
$ustr
);
$ustr
=
str_replace
(
'&'
,
'[b]'
,
$ustr
);
$ustr
=
str_replace
(
'/'
,
'[c]'
,
$ustr
);
return
$ustr
;
}
}
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