+
+ if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
+ drbg->core->backend_cra_name) >= CRYPTO_MAX_ALG_NAME) {
+ drbg_fini_sym_kernel(drbg);
+ return -EINVAL;
+ }
+ sk_tfm = crypto_alloc_skcipher(ctr_name, 0, 0);
+ if (IS_ERR(sk_tfm)) {
+ pr_info("DRBG: could not allocate CTR cipher TFM handle: %s\n",
+ ctr_name);
+ drbg_fini_sym_kernel(drbg);
+ return PTR_ERR(sk_tfm);
+ }
+ drbg->ctr_handle = sk_tfm;
+
+ req = skcipher_request_alloc(sk_tfm, GFP_KERNEL);
+ if (!req) {
+ pr_info("DRBG: could not allocate request queue\n");
+ drbg_fini_sym_kernel(drbg);
+ return PTR_ERR(req);
+ }
+ drbg->ctr_req = req;
+ skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ drbg_skcipher_cb, drbg);
+
+ alignmask = crypto_skcipher_alignmask(sk_tfm);
+ drbg->ctr_null_value_buf = kzalloc(DRBG_CTR_NULL_LEN + alignmask,
+ GFP_KERNEL);
+ if (!drbg->ctr_null_value_buf) {
+ drbg_fini_sym_kernel(drbg);
+ return -ENOMEM;
+ }
+ drbg->ctr_null_value = (u8 *)PTR_ALIGN(drbg->ctr_null_value_buf,
+ alignmask + 1);
+
+ return alignmask;