__init__.py 文件源码

def _gen_key_initctr(cls, b_password, b_salt):
        # 16 for AES 128, 32 for AES256
        keylength = 32

        # match the size used for counter.new to avoid extra work
        ivlength = 16

        if HAS_PBKDF2HMAC:
            backend = default_backend()
            kdf = PBKDF2HMAC(
                algorithm=c_SHA256(),
                length=2 * keylength + ivlength,
                salt=b_salt,
                iterations=10000,
                backend=backend)
            b_derivedkey = kdf.derive(b_password)
        else:
            b_derivedkey = cls._create_key(b_password, b_salt, keylength, ivlength)

        b_key1 = b_derivedkey[:keylength]
        b_key2 = b_derivedkey[keylength:(keylength * 2)]
        b_iv = b_derivedkey[(keylength * 2):(keylength * 2) + ivlength]

        return b_key1, b_key2, hexlify(b_iv)