python实现维吉尼亚解密

# -*-coding:UTF-8-*-
from sys import  stdout
miwen = "KCCPKBGUFDPHQTYAVINRRTMVGRKDNBVFDETDGILTXRGUD DKOTFMBPVGEGLTGCKQRACQCWDNAWCRXIZAKFTLEWRPTYCQKYVXCHKFTPONCQQRHJVAJUWETMCMSPKQDYHJVDAHCTRLSVSKCGCZQQDZXGSFRLSWCWSJTBHAFSIASPRJAHKJRJUMVGKMITZHFPDISPZLVLGWTFPLKKEBDPGCEBSHCTJRWXBAFSPEZQNRWXCVYCGAONWDDKACKAWBBIKFTIOVKCGGHJVLNHIFFSQESVYCLACNVRWBBIREPBBVFEXOSCDYGZWPFDTKFQIY CWHJVLNHIQIBTKHJVNPIST"
Ix = 0.065
ziranpinlv=[0.081,0.014,0.038,0.039,0.122,0.022,0.017,0.045,0.071,0.001,0.004,0.037,0.034,0.070,0.072,0.028,0.000,0.068,0.063,0.094, 0.025,0.010,0.015,0.002,0.015,0.000]
print ziranpinlv.__len__()
huifufenzu = []
huifupianduan = ""
def keylength(miwen): #计算秘钥长度
    miwen = miwen.replace(" ", "") #替换掉密文中的空格
    chushimiwenlen = miwen.__len__()
    fenzumiwenlen = chushimiwenlen
    left = 0
    right = 0
    max_pinlv = 0
    key_len = 0
    for i in range(2,8):#安装ｋｅｙ不同长度进行分组
        while 0!=(fenzumiwenlen%i):
            fenzumiwenlen=fenzumiwenlen-1
        jianju =  i
        right = i
        fenzu=[]
        while(right<=fenzumiwenlen):
            fenzu.append(miwen[left:right])
            left = right
            right = right+jianju
        left = 0
        right = 0
        jianju = 0
        mm = ""
        for m in range(1, chushimiwenlen - fenzumiwenlen + 1):
            mm = miwen[-m] + mm
        fenzu.append(mm)
        fenzumiwenlen = chushimiwenlen
        mm = ""
        xinfenzu = []
        for q in range(i):
            xinfenzu.append("")
        for w in range(i):
            for y in range(fenzu.__len__()):
                if  fenzu[y].__len__()>= w+1:
                    xinfenzu[w] = xinfenzu[w]+ fenzu[y][w]
        pinlv = []
        for pp in range(xinfenzu.__len__()):
            pinlv.append(0)
        fenzupinlv = []
        fenzupinlv = jisuanpinlv(xinfenzu,fenzupinlv)
        for ppp  in range(xinfenzu.__len__()):
            for pppp in range(ppp*26,(ppp+1)*26):
                pinlv[ppp] = round(pinlv[ppp]+ fenzupinlv[pppp]*fenzupinlv[pppp],3)
        pingjun = 0
        for oo in range(pinlv.__len__()):
            pingjun = pingjun + pinlv[oo]
        pingjun = round(pingjun/pinlv.__len__(),5)
        if pingjun > max_pinlv:
            max_pinlv = pingjun
            key_len = pinlv.__len__()
    decrypt(miwen,chushimiwenlen,key_len)
def jisuanpinlv(xinfenzu,fenzupinlv):#
    for l in range(xinfenzu.__len__()):
        for a in range(65, 91):
            zimuchuxiancishu = 0
            for zimu in xinfenzu[l]:
                if chr(a) == zimu:
                    zimuchuxiancishu = zimuchuxiancishu + 1
            fenzupinlv.append(round(float(zimuchuxiancishu)/float(xinfenzu[l].__len__()),3))
    return fenzupinlv
def decrypt(miwen,chushimiwenlen,key_len):
        i = key_len #进行分组
        xinfenzu = []
        fenzumiwenlen = chushimiwenlen
        while 0!=(fenzumiwenlen%i):
            fenzumiwenlen -= 1
        jianju =  i
        right = i
        fenzu=[]
        left = 0
        while(right<=fenzumiwenlen):
            fenzu.append(miwen[left:right])
            left = right
            right = right+jianju
        mm = ""
        for m in range(1, chushimiwenlen - fenzumiwenlen + 1):
            mm = miwen[-m] + mm
        fenzu.append(mm)
        fenzumiwenlen = chushimiwenlen
        xinfenzu = []
        for q in range(i):
            xinfenzu.append("")
        for w in range(i):
            for y in range(fenzu.__len__()):
                if  fenzu[y].__len__()>= w+1:
                    xinfenzu[w] = xinfenzu[w]+ fenzu[y][w]
        print xinfenzu
        plaintext(xinfenzu)
def plaintext(xinfenzu):
    fenzupinlv = []
    for l in range(xinfenzu.__len__()):
        for a in range(65, 91):
            zimuchuxiancishu = 0
            for zimu in xinfenzu[l]:
                if chr(a) == zimu:
                    zimuchuxiancishu = zimuchuxiancishu + 1
            fenzupinlv.append(round(float(zimuchuxiancishu)/float(xinfenzu[l].__len__()),3))
        k = shift(fenzupinlv[l*26:(l+1)*26])
        mingwenpianduan = shuchumingwen(xinfenzu[l],k)
        global huifufenzu
        huifufenzu.append(mingwenpianduan)
    print huifufenzu
    huifu()
def shift(fenzupinlv):
    Mg = 0
    max_k = 0
    fenzu_k = []
    for i in range(26):
        for j  in range(26):
            Mg = Mg + round(fenzupinlv[(j+i)%26]*ziranpinlv[j],3)

        fenzu_k.append(round(Mg,3))
        Mg = 0
    return fenzu_k.index(max(fenzu_k))
def shuchumingwen(xinfenzu,k):
    global huifupianduan
    huifupianduan= ""
    for hh in range(xinfenzu.__len__()):
            if ord(xinfenzu[hh])-k>=65:
                huifupianduan = huifupianduan + chr(ord(xinfenzu[hh])-k)
            if ord(xinfenzu[hh])-k<65:
                huifupianduan = huifupianduan + chr((ord(xinfenzu[hh])-65-k)%91)
    return huifupianduan
def huifu():
    global huifufenzu
    mingwen = ""
    for i in range(huifufenzu.__len__()):
        if i == 0:
            mingwen = mingwen + huifufenzu[i][:56]
        else:
            mingwen = mingwen +huifufenzu[i]
    for k in range(56):
        for j in range(k,mingwen.__len__(),56):
            stdout.write(mingwen[j])
    stdout.write(huifufenzu[0][-1:])
keylength(miwen)