PKCS1.py 文件源码

def unpad_PKCS1(message : int, size_block : int) -> int:
    """
    PKCS1 unpadding function
    """

    pts = 0xff << (size_block - 24)

    while (pts & message != 0):
        pts = pts >> 8

    a = ~pts & ((1 << size_block) - 1)

    message = message & (~pts & ((1 << math.ceil(math.log2(pts))) - 1) )

    return message