cbc_keysched
encrypt(ctx->cbc_keysched, blockp, blockp);
encrypt(ctx->cbc_keysched, lastp, lastp);
decrypt(ctx->cbc_keysched, blockp,
decrypt(ctx->cbc_keysched, blockp, blockp);
encrypt_block(cbc_ctx->cbc_keysched, buf, buf);
encrypt_block(cbc_ctx->cbc_keysched, M_last, M_last);
encrypt_block(cbc_ctx->cbc_keysched, M_last, M_last);
cbc_ctx->cbc_keysched = key_sched;
cbc_ctx->cbc_keysched = key_sched;