+
+ struct crypto_shash *parent = pdesc->tfm;
+ int ds = crypto_shash_digestsize(parent);
+ int ss = crypto_shash_statesize(parent);
+ char *opad = crypto_shash_ctx_aligned(parent) + ss;
+ struct shash_desc *desc = shash_desc_ctx(pdesc);
+
+ desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ return crypto_shash_finup(desc, data, nbytes, out) ?:
+ crypto_shash_import(desc, opad) ?:
+ crypto_shash_finup(desc, out, ds, out);
+}
+
+static int hmac_init_tfm(struct crypto_tfm *tfm)
+{
+ struct crypto_shash *parent = __crypto_shash_cast(tfm);
+ struct crypto_shash *hash;
+ struct crypto_instance *inst = (void *)tfm->__crt_alg;
+ struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst);
+ struct hmac_ctx *ctx = hmac_ctx(parent);
+
+ hash = crypto_spawn_shash(spawn);
+ if (IS_ERR(hash))
+ return PTR_ERR(hash);
+
+ parent->descsize = sizeof(struct shash_desc) +
+ crypto_shash_descsize(hash);
+
+ ctx->hash = hash;
+ return 0;
+}
+
+static void hmac_exit_tfm(struct crypto_tfm *tfm)
+{
+ struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));
+ crypto_free_shash(ctx->hash);
+}
+
+static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
+{
+ struct shash_instance *inst;
+ struct crypto_alg *alg;
+ struct shash_alg *salg;
+ int err;
+ int ds;
+ int ss;
+
+ err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
+ if (err)
+ return err;
+
+ salg = shash_attr_alg(tb[1], 0, 0);
+ if (IS_ERR(salg))
+ return PTR_ERR(salg);
+
+ err = -EINVAL;
+ ds = salg->digestsize;
+ ss = salg->statesize;
+ alg = &salg->base;
+ if (ds > alg->cra_blocksize ||
+ ss < alg->cra_blocksize)
+ goto out_put_alg;
+
+ inst = shash_alloc_instance("hmac", alg);
+ err = PTR_ERR(inst);
+ if (IS_ERR(inst))
+ goto out_put_alg;
+
+ err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg,
+ shash_crypto_instance(inst));
+ if (err)
+ goto out_free_inst;
+
+ inst->alg.base.cra_priority = alg->cra_priority;
+ inst->alg.base.cra_blocksize = alg->cra_blocksize;
+ inst->alg.base.cra_alignmask = alg->cra_alignmask;
+
+ ss = ALIGN(ss, alg->cra_alignmask + 1);
+ inst->alg.digestsize = ds;
+ inst->alg.statesize = ss;
+
+ inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
+ ALIGN(ss * 2, crypto_tfm_ctx_alignment());
+
+ inst->alg.base.cra_init = hmac_init_tfm;
+ inst->alg.base.cra_exit = hmac_exit_tfm;
+
+ inst->alg.init = hmac_init;
+ inst->alg.update = hmac_update;
+ inst->alg.final = hmac_final;
+ inst->alg.finup = hmac_finup;
+ inst->alg.export = hmac_export;
+ inst->alg.import = hmac_import;
+ inst->alg.setkey = hmac_setkey;
+
+ err = shash_register_instance(tmpl, inst);
+ if (err) {
+out_free_inst:
+ shash_free_instance(shash_crypto_instance(inst));