memset((*ctx)+KEYSIZE_B, 0, 35-KEYSIZE_B);
memcpy((*ctx), key, KEYSIZE_B);
memcpy((*ctx)+12, iv, IVSIZE_B); /* iv0 is at s96, must shift to s93 */
memset((*ctx)+KEYSIZE_B, 0, 35-KEYSIZE_B);
memcpy((*ctx), key, KEYSIZE_B);
memcpy((*ctx)+12, iv, IVSIZE_B); /* iv0 is at s96, must shift to s93 */