pyc文件。
文件头有问题。修改一下文件头，然后编译成py文件
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from ctypes import *
from Crypto.Util.number import bytes_to_long
from Crypto.Util.number import long_to_bytes
def encrypt(v, k):
v0 = c_uint32(v[0])
v1 = c_uint32(v[1])
sum1 = c_uint32(0)
delta = 195935983
for i in range(32):
v0.value += (v1.value << 4 ^ v1.value >> 7) + v1.value ^ sum1.value + k[(sum1.value & 3)]
sum1.value += delta
v1.value += (v0.value << 4 ^ v0.value >> 7) + v0.value ^ sum1.value + k[(sum1.value >> 9 & 3)]
return (
v0.value, v1.value)
if __name__ == '__main__':
flag = input('please input your flag:')
k = [255, 187, 51, 68]
if len(flag) != 32:
print('wrong!')
exit(-1)
a = []
for i in range(0, 32, 8):
v1 = bytes_to_long(bytes(flag[i:i + 4], 'ascii'))
v2 = bytes_to_long(bytes(flag[i + 4:i + 8], 'ascii'))
a += encrypt([v1, v2], k)
enc = [
4006073346, 2582197823, 2235293281, 558171287, 2425328816, 1715140098, 986348143, 1948615354]
for i in range(8):
if enc[i] != a[i]:
print('wrong!')
exit(-1)
print('flag is flag{%s}' % flag)
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v1 = bytes_to_long(bytes(flag[i:i + 4], 'ascii'))
v2 = bytes_to_long(bytes(flag[i + 4:i + 8], 'ascii'))
a += encrypt([v1, v2], k)
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这个代码就是把flag拆分一下。
for i in range(32):
v0.value += (v1.value << 4 ^ v1.value >> 7) + v1.value ^ sum1.value + k[(sum1.value & 3)]
sum1.value += delta
v1.value += (v0.value << 4 ^ v0.value >> 7) + v0.value ^ sum1.value + k[(sum1.value >> 9 & 3)]
这里是一个类似于tea加密的方式。【但不是tea】
先将flag，char类型化成2个int类型为一组的数据。然后将2个int类型的数据进行tea加密。
解密：将2个int类型的数据进行解密，得到2个解密后的int类型，再将他转化成char类型。
解密：
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int main()
{
u_int enc[] = { 4006073346, 2582197823, 2235293281, 558171287,
2425328816, 1715140098, 986348143, 1948615354 };
u_int k[] = { 255, 187, 51, 68 };
for (int i = 0; i < 8; i += 2)
{
u_int delta = 195935983;
u_int s1 = delta * 32; //因为加密代码中 是+了32次，这里需要--，所以就先*32
for (int j = 0; j < 32; j++)
{
enc[i + 1] -= (enc[i] << 4 ^ enc[i] >> 7) + enc[i] ^ s1 + k[s1 >> 9 & 3];
s1 -= delta;
enc[i] -= (enc[i + 1] << 4 ^ enc[i + 1] >> 7) + enc[i + 1] ^ s1 + k[s1 & 3];
}
}
char flag[32] = { 0 };
for (int i = 0; i < 8; i++)
{//下面是int类型转成char类型
flag[4 * i] = enc[i] >> 24;
flag[4 * i + 1] = (enc[i] >> 16) ^ 0xFF000000;
flag[4 * i + 2] = (enc[i] >> 8) ^ 0xFF000000;
flag[4 * i + 3] = enc[i] ^ 0xFF000000;
}
for (int i = 0; i < 32; i++)
{
printf("%c", flag[i]);
}
}
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