PHP的等價物Mcrypt

Question

我在PHP中編寫了下面的DES加密方案。它採用了靜態初始化向量，以確保輸出和輸入是一對一的映射

PHP代碼：

function encrypt($plaintext, $key) 
{ 
    # use an explicit encoding for the plain text 
    $plaintext_utf8 = utf8_encode($plaintext); 

    # create a random IV to use with CBC encoding 
    # $iv_size = mcrypt_get_iv_size(MCRYPT_DES, MCRYPT_MODE_CBC); 
    # $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); 
    # defining a constant IV to use with CBC encoding 
    $iv = "kritanj "; 

    # creates the DES cipher text 
    $ciphertext = mcrypt_encrypt(MCRYPT_DES, $key, $plaintext_utf8, MCRYPT_MODE_CBC, $iv); 
    # prepend the IV for it to be available for decryption 
    $ciphertext = $iv . $ciphertext; 

    # encode the resulting cipher text so it can be represented by a string 
    $ciphertext_base64 = base64_encode($ciphertext); 

    return $ciphertext_base64; 
} 

function decrypt($ciphertext_base64, $key) 
{ 
    $ciphertext_dec = base64_decode($ciphertext_base64); 

    # retrieves the IV, iv_size should be created using mcrypt_get_iv_size() 
    # $iv_size = mcrypt_get_iv_size(MCRYPT_DES, MCRYPT_MODE_CBC); 
    # $iv = substr($ciphertext_dec, 0, $iv_size); 
    $iv = "kritanj "; 

    # retrieves the cipher text (everything except the $iv_size in the front) 
    $ciphertext_dec = substr($ciphertext_dec, $iv_size); 

    # decrypting the DES cipher text 
    $plaintext_utf8_dec = mcrypt_decrypt(MCRYPT_DES, $key, $ciphertext_dec, MCRYPT_MODE_CBC, $iv); 
    return $plaintext_utf8_dec; 
} 

$plaintext = "The secret message is : " ; 
$key = "7chrkey" ; 
$ciphertext = encrypt($plaintext, $key); 
echo "Encrypted: ".$ciphertext ."<br>"; 
$plaintext1 = decrypt($ciphertext, $key); 
echo "Decrypted: ".$plaintext1 ; 

輸出：

Encrypted: a3JpdGFuaiB3DY63WHnE9led43FyFe53HlhUEr+vVJg= 
Decrypted: The secret message is : 

現在我試着寫一個等效代碼python 這是我管理的

Python代碼：

import binascii 
def conv_sevnCharKey_to_64bit_DESkey(key): 
    st = bin(int(binascii.hexlify(key), 16)) 
    st = st[2:] 
    des_key = '' 
    for i in xrange(8) : 
    parity = 0 
    sevnBits = st[i*7:i*7+7] 
    for c in sevnBits : 
     if c in '1' : 
     parity += 1 
    if parity % 2 == 0 : 
     eigthBytes = sevnBits + '1' 
    else : 
     eigthBytes = sevnBits + '0' 
    des_key += eigthBytes 

    n = int('0b'+des_key, 2) 
    DESkey = binascii.unhexlify('%x' % n) 

    return DESkey 

from pyDes import * 
plaintext = "The secret message is : " 
iv = 'kritanj ' 
key = conv_sevnCharKey_to_64bit_DESkey('7chrkey') 

plaintext_utf8 = plaintext.encode('utf-8') 
# iniltalizing DES in cbc mode  
k = des(key, CBC, iv) 
# encrypting 
ciphertext = k.encrypt(plaintext_utf8) 
# prepending the IV 
ciphertext = iv + ciphertext; 
# encoding to base64 
ciphertext_base64 = ciphertext.encode('base64','strict') 

print "Encrypted: ", ciphertext_base64 

# decoding base64 
ciphertext= ciphertext_base64.decode('base64','strict') 
# striping the IV and decrypting 
plaintext_utf8 = k.decrypt(ciphertext[8:]) 
# decoding utf-8 (if nessacary) 
plaintext1 = plaint`ext_utf8.decode('utf-8') 

print "Decrypted: ", plaintext1 

assert plaintext1== plaintext 

輸出：

Encrypted: a3JpdGFuaiD+sGHb2GfZSXDac1r6mH+JDx7535yxL9k= 

Decrypted: The secret message is : 

爲什麼是密文有什麼不同？有沒有辦法確保它們是相同的？

[我想在使用上面的php代碼的雙DES加密下加密的文本中發生'中間相遇'攻擊。 但因爲我不能重現我不能實施攻擊]

Answer 1

看起來你的方案墊加密從PHP代碼的關鍵不同：

from pyDes import * 
plaintext = "The secret message is : " 
iv = 'kritanj ' 
key = '7chrkey' 
plaintext = plaintext.encode("utf-8") 
iv = 'kritanj ' 
k = des(key+'\0', CBC, iv) 
print (iv + k.encrypt(plaintext)).encode("base64", "strict") 

輸出：

'a3JpdGFuaiB3DY63WHnE9led43FyFe53HlhUEr+vVJg=\n' 

在簡而言之：用NULL字節填充加密密鑰將產生與您的PHP代碼相同的結果。