加密解密 - asp实例

加密前为:1234567890
加密后为:MTIzNDU2Nzg5MA
解密后为:1234567890
源码:
<%
OPTION EXPLICIT
const BASE_64_MAP_INIT = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
dim newline
dim Base64EncMap(63)
dim Base64DecMap(127)
'初始化函数
PUBLIC SUB initCodecs()
' 初始化变量
newline = "<P>" & chr(13) & chr(10)
dim max, idx
max = len(BASE_64_MAP_INIT)
for idx = 0 to max - 1
Base64EncMap(idx) = mid(BASE_64_MAP_INIT, idx + 1, 1)
next
for idx = 0 to max - 1
Base64DecMap(ASC(Base64EncMap(idx))) = idx
next
END SUB
'Base64加密函数
PUBLIC FUNCTION base64Encode(plain)
if len(plain) = 0 then
base64Encode = ""
exit function
end if
dim ret, ndx, by3, first, second, third
by3 = (len(plain) 3) * 3
ndx = 1
do while ndx <= by3
first = asc(mid(plain, ndx+0, 1))
second = asc(mid(plain, ndx+1, 1))
third = asc(mid(plain, ndx+2, 1))
ret = ret & Base64EncMap( (first 4) AND 63 )
ret = ret & Base64EncMap( ((first * 16) AND 48) + ((second 16) AND 15 ) )
ret = ret & Base64EncMap( ((second * 4) AND 60) + ((third 64) AND 3 ) )
ret = ret & Base64EncMap( third AND 63)
ndx = ndx + 3
loop
if by3 < len(plain) then
first = asc(mid(plain, ndx+0, 1))
ret = ret & Base64EncMap( (first 4) AND 63 )
if (len(plain) MOD 3 ) = 2 then
second = asc(mid(plain, ndx+1, 1))
ret = ret & Base64EncMap( ((first * 16) AND 48) + ((second 16) AND 15 ) )
ret = ret & Base64EncMap( ((second * 4) AND 60) )
else
ret = ret & Base64EncMap( (first * 16) AND 48)
ret = ret '& "="
end if
ret = ret '& "="
end if
base64Encode = ret
END FUNCTION
'Base64解密函数
PUBLIC FUNCTION base64Decode(scrambled)
if len(scrambled) = 0 then
base64Decode = ""
exit function

补充：asp教程,高级应用