TOP5流行的加密算法#

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import struct
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def tea_encrypt(plaintext, key, rounds=32):
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    v0, v1 = struct.unpack('>2I', plaintext)
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    k0, k1, k2, k3 = struct.unpack('>4I', key)
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    delta = 0x9E3779B9
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    sum_val = 0
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    mask = 0xFFFFFFFF
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    for _ in range(rounds):
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        sum_val = (sum_val + delta) & mask
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        v0 = (v0 + (((v1 << 4) + k0) ^ (v1 + sum_val) ^ ((v1 >> 5) + k1))) & mask
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        v1 = (v1 + (((v0 << 4) + k2) ^ (v0 + sum_val) ^ ((v0 >> 5) + k3))) & mask
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    return struct.pack('>2I', v0, v1)
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def tea_decrypt(ciphertext, key, rounds=32):
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    v0, v1 = struct.unpack('>2I', ciphertext)
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    k0, k1, k2, k3 = struct.unpack('>4I', key)
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    delta = 0x9E3779B9
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    sum_val = (delta * rounds) & 0xFFFFFFFF
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    mask = 0xFFFFFFFF
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    for _ in range(rounds):
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        v1 = (v1 - (((v0 << 4) + k2) ^ (v0 + sum_val) ^ ((v0 >> 5) + k3))) & mask
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        v0 = (v0 - (((v1 << 4) + k0) ^ (v1 + sum_val) ^ ((v1 >> 5) + k1))) & mask
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        sum_val = (sum_val - delta) & mask
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    return struct.pack('>2I', v0, v1)
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if __name__ == "__main__":
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    plaintext = b'Hello!!!'  # 8 字节明文
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    key = b'0123456789ABCDEF'  # 16 字节密钥
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    print(f"明文: {plaintext}")
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    print(f"密钥: {key}")
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    # 加密
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    ciphertext = tea_encrypt(plaintext, key)
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    print(f"密文 (hex): {ciphertext.hex()}")
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    # 解密
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    decrypted = tea_decrypt(ciphertext, key)
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    print(f"解密: {decrypted}")

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def rc4(data, key):
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    S = list(range(256))
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    j = 0
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    for i in range(256):
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        j = (j + S[i] + key[i % len(key)]) % 256
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        S[i], S[j] = S[j], S[i]
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    i = 0
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    j = 0
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    out = bytearray()
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    for b in data:
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        i = (i + 1) % 256
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        j = (j + S[i]) % 256
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        S[i], S[j] = S[j], S[i]
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        out.append(b ^ S[(S[i] + S[j]) % 256])
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    return bytes(out)
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if __name__ == "__main__":
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    key = b"coka cola espuma"
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    cipher = bytes.fromhex("91 A5 F9 17 24 64 9A A7 75 A7 51 84 8B")
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    print(rc4(cipher, key).decode())

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import base64
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def b64_encrypt(text):
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    return base64.b64encode(text.encode()).decode()
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def b64_decrypt(text):
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    return base64.b64decode(text).decode()
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# 用例
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plain = "BV1UW4y1N79w"
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cipher = b64_encrypt(plain)
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print(f"Base64: {b64_decrypt(cipher) == plain}")

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def xor_crypt(text, key_byte):
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    return "".join(chr(ord(c) ^ key_byte) for c in text)
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key = 0x2A
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plain = "mamashengde"
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cipher = xor_crypt(plain, key)
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print(f"XOR: {xor_crypt(cipher, key) == plain}")

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import struct
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def xtea_encrypt(text, key, rounds=42):
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    v0, v1 = struct.unpack("<II", text)
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    k = struct.unpack("<IIII", key)
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    delta = 0x9E3779B9
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    sum_val = 0
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    for _ in range(rounds):
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        v0 = (v0 + ((((v1 << 4) & 0xFFFFFFFF) ^ (v1 >> 5)) + v1) ^ (sum_val + k[sum_val & 3])) & 0xFFFFFFFF
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        sum_val = (sum_val + delta) & 0xFFFFFFFF
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        v1 = (v1 + ((((v0 << 4) & 0xFFFFFFFF) ^ (v0 >> 5)) + v0) ^ (sum_val + k[(sum_val >> 11) & 3])) & 0xFFFFFFFF
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    return struct.pack("<II", v0, v1)
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def xtea_decrypt(text, key, rounds=42):
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    v0, v1 = struct.unpack("<II", text)
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    k = struct.unpack("<IIII", key)
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    delta = 0x9E3779B9
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    sum_val = (delta * rounds) & 0xFFFFFFFF
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    for _ in range(rounds):
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        v1 = (v1 - ((((v0 << 4) & 0xFFFFFFFF) ^ (v0 >> 5)) + v0) ^ (sum_val + k[(sum_val >> 11) & 3])) & 0xFFFFFFFF
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        sum_val = (sum_val - delta) & 0xFFFFFFFF
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        v0 = (v0 - ((((v1 << 4) & 0xFFFFFFFF) ^ (v1 >> 5)) + v1) ^ (sum_val + k[sum_val & 3])) & 0xFFFFFFFF
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    return struct.pack("<II", v0, v1)
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key = b"coka cola espuma"
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plain = b"TOP5+enc"
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cipher = xtea_encrypt(plain, key)
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print(f"XTEA: {xtea_decrypt(cipher, key) == plain}")