我在 python 中实现 AESENC x86 指令时遇到问题。
我正在对独立视频游戏的解密进行逆向工程。他们使用 AES 但他们异或一些生成的数据并且密钥扩展不是标准的，所以我需要使用自定义轮密钥。我几乎完成了，但我很难过游戏使用 AESENC x86 指令，该指令执行单轮 AES。这似乎很容易实现，但我没有得到相同的结果。
更准确地说，在设置断点和查看内存时
AESENC(E98E03FAEAD91A951F6269D0D4DAFAD6, C62E6AD8CC162D7E210D91A142F2927B)
返回：
AABCA9C13C842D3112C48E822B050CF8
虽然我的 python 实现返回：
aabca9c13b88ae173e2ea2680d02007b
这似乎只匹配前 4 个字节。我的猜测是 mix_columns 步骤做错了，我尝试了其他实现，但似乎没有一个与 x86 指令匹配。我正在使用The Design of Rijndael Section 4.1.2一书中的实现
我在 AESENC 上找到的唯一文档是here，不幸的是，它没有详细说明这些功能是如何实现的。如果有人知道我可以在哪里获得 AESENC 的实现细节，请执行 :)
到目前为止，这是我对 AESENC 的完整 Python 实现：
SBOX = (
0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16,
)
def list2hex(list):
hex = ""
for e in list:
hex += "{:02x}".format(e)
return hex
def hex2list(hex):
lst = []
if len(hex) % 2 == 0:
for i in range(len(hex)/2):
lst.append(int(hex[i*2:i*2+2], 16))
return lst
def xor(bytelist1, bytelist2):
res = []
length = min(len(bytelist1), len(bytelist2))
for i in range(length):
res.append(bytelist1[i] ^ bytelist2[i])
return res
def aesenc(state, roundkey, last=False):
def shift_rows(state):
state[4], state[5], state[6], state[7] = state[5], state[6], state[7], state[4]
state[8], state[9], state[10], state[11] = state[10], state[11], state[8], state[9]
state[12], state[13], state[14], state[15] = state[15], state[12], state[13], state[14]
def sub_bytes(state):
for i in range(16):
state[i] = SBOX[state[i]]
def mix_columns(state):
xtime = lambda a: (((a << 1) ^ 0x1B) & 0xFF) if (a & 0x80) else (a << 1)
def mix_column(col):
t = col[0] ^ col[1] ^ col[2] ^ col[3]
u = col[0]
col[0] ^= t ^ xtime(col[0] ^ col[1])
col[1] ^= t ^ xtime(col[1] ^ col[2])
col[2] ^= t ^ xtime(col[2] ^ col[3])
col[3] ^= t ^ xtime(col[3] ^ u)
return _col
return mix_column(state[0::4]) + \
mix_column(state[1::4]) + \
mix_column(state[2::4]) + \
mix_column(state[3::4])
sub_bytes(state)
shift_rows(state)
if not last:
state = mix_columns(state)
return xor(state, roundkey)
data = hex2list("E98E03FAEAD91A951F6269D0D4DAFAD6")
key = hex2list("C62E6AD8CC162D7E210D91A142F2927B")
res = aesenc(data, key)
print list2hex(res)