import base64

s1 = base64.encodestring('hello world')
s2 = base64.decodestring(s1)
print s1,s2

# aGVsbG8gd29ybGQ=\n
# hello world

import win32com.client
def encrypt(key,content): # key:密钥,content:明文
    EncryptedData = win32com.client.Dispatch('CAPICOM.EncryptedData')
    EncryptedData.Algorithm.KeyLength = 5
    EncryptedData.Algorithm.Name = 2
    EncryptedData.SetSecret(key)
    EncryptedData.Content = content
    return EncryptedData.Encrypt()

def decrypt(key,content): # key:密钥,content:密文
    EncryptedData = win32com.client.Dispatch('CAPICOM.EncryptedData')
    EncryptedData.Algorithm.KeyLength = 5
    EncryptedData.Algorithm.Name = 2
    EncryptedData.SetSecret(key)
    EncryptedData.Decrypt(content)
    str = EncryptedData.Content
    return str

s1 = encrypt('lovebread', 'hello world')
s2 = decrypt('lovebread', s1)
print s1,s2

# MGEGCSsGAQQBgjdYA6BUMFIGCisGAQQBgjdYAwGgRDBCAgMCAAECAmYBAgFABAgq
# GpllWj9cswQQh/fnBUZ6ijwKDTH9DLZmBgQYmfaZ3VFyS/lq391oDtjlcRFGnXpx
# lG7o
# hello world

def encrypt(key, s):
    b = bytearray(str(s).encode("gbk"))
    n = len(b) # 求出 b 的字节数
    c = bytearray(n*2)
    j = 0
    for i in range(0, n):
        b1 = b[i]
        b2 = b1 ^ key # b1 = b2^ key
        c1 = b2 % 16
        c2 = b2 // 16 # b2 = c2*16 + c1
        c1 = c1 + 65
        c2 = c2 + 65 # c1,c2都是0~15之间的数,加上65就变成了A-P 的字符的编码
        c[j] = c1
        c[j+1] = c2
        j = j+2
    return c.decode("gbk")

def decrypt(key, s):
    c = bytearray(str(s).encode("gbk"))
    n = len(c) # 计算 b 的字节数
    if n % 2 != 0 :
        return ""
    n = n // 2
    b = bytearray(n)
    j = 0
    for i in range(0, n):
        c1 = c[j]
        c2 = c[j+1]
        j = j+2
        c1 = c1 - 65
        c2 = c2 - 65
        b2 = c2*16 + c1
        b1 = b2^ key
        b[i]= b1
    try:
        return b.decode("gbk")
    except:
        return "failed"

key = 15
s1 = encrypt(key, 'hello world')
s2 = decrypt(key, s1)
print s1,'\n',s2

# HGKGDGDGAGPCIHAGNHDGLG
# hello world