使用Python实现RC4算法

Python代码：

'''

Created on 2011-6-21

@author: shanks

'''

def rc4(data, key):

    '''

        data:    data that to be encrypted or decrypted.

        key:     key to encrypt or decrypt. 

    '''

    #some parameters check here ...

    #if the data is a string, convert to hex format.

    if(type(data) is type("string")):

        tmpData=data

        data=[]

        for tmp in tmpData:

            data.append(ord(tmp))

    #if the key is a string, convert to hex format.

    if(type(key) is type("string")):

        tmpKey=key

        key=[]

        for tmp in tmpKey:

            key.append(ord(tmp))

    #the Key-Scheduling Algorithm

    x = 0

    box= list(range(256))

    for i in range(256):

        x = (x + box[i] + key[i % len(key)]) % 256

        box[i], box[x] = box[x], box[i]

    #the Pseudo-Random Generation Algorithm

    x = 0

    y = 0

    out = []

    for c in data:

        x = (x + 1) % 256

        y = (y + box[x]) % 256

        box[x], box[y] = box[y], box[x]

        out.append(c ^ box[(box[x] + box[y]) % 256])

    result=""

    printable=True

    for tmp in out:

        if(tmp<;0x21 or tmp>0x7e):

            # there is non-printable character

            printable=False

            break

        result += chr(tmp)

    if(printable==False):

        result=""

        #convert to hex string   

        for tmp in out:

            result += "{0:02X}".format(tmp)

    return result

测试代码：

out=rc4("shanks", "vulnhunt")

print("shanks encryption:{}".format(out))

out=rc4([0xA0,0xD8,0x56,0x83,0xF0,0x9D], "vulnhunt")

print("[0xA0,0xD8,0x56,0x83,0xF0,0x9D] decryption:{}".format(out))

out=rc4("shanks", [0xA0,0xD8,0x56,0x83,0xF0,0x9D])

print("shanks encryption:{}".format(out))

out=rc4([0x3C,0x51,0x8F,0x52,0xA1,0x91], [0xA0,0xD8,0x56,0x83,0xF0,0x9D])

print("[0x3C,0x51,0x8F,0x52,0xA1,0x91] decryption:{}".format(out))

out=rc4([0xA0,0xD8,0x56,0x83,0xF0,0x9D], [0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09])

print("[0xA0,0xD8,0x56,0x83,0xF0,0x9D] encryption:{}".format(out))

out=rc4([0x18,0x48,0x33,0xc8,0x50,0xB3], [0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09])

print("[0x18,0x48,0x33,0xc8,0x50,0xB3] decryption:{}".format(out))

执行结果：