// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Crypto API support for BLAKE2b
 *
 * Copyright 2025 Google LLC
 */
#include <crypto/blake2b.h>
#include <crypto/internal/hash.h>
#include <linux/kernel.h>
#include <linux/module.h>

struct blake2b_tfm_ctx {
        unsigned int keylen;
        u8 key[BLAKE2B_KEY_SIZE];
};

static int crypto_blake2b_setkey(struct crypto_shash *tfm,
                                 const u8 *key, unsigned int keylen)
{
        struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(tfm);

        if (keylen > BLAKE2B_KEY_SIZE)
                return -EINVAL;
        memcpy(tctx->key, key, keylen);
        tctx->keylen = keylen;
        return 0;
}

#define BLAKE2B_CTX(desc) ((struct blake2b_ctx *)shash_desc_ctx(desc))

static int crypto_blake2b_init(struct shash_desc *desc)
{
        const struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
        unsigned int digestsize = crypto_shash_digestsize(desc->tfm);

        blake2b_init_key(BLAKE2B_CTX(desc), digestsize,
                         tctx->key, tctx->keylen);
        return 0;
}

static int crypto_blake2b_update(struct shash_desc *desc,
                                 const u8 *data, unsigned int len)
{
        blake2b_update(BLAKE2B_CTX(desc), data, len);
        return 0;
}

static int crypto_blake2b_final(struct shash_desc *desc, u8 *out)
{
        blake2b_final(BLAKE2B_CTX(desc), out);
        return 0;
}

static int crypto_blake2b_digest(struct shash_desc *desc,
                                 const u8 *data, unsigned int len, u8 *out)
{
        const struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
        unsigned int digestsize = crypto_shash_digestsize(desc->tfm);

        blake2b(tctx->key, tctx->keylen, data, len, out, digestsize);
        return 0;
}

#define BLAKE2B_ALG(name, digest_size)                                  \
        {                                                               \
                .base.cra_name          = name,                         \
                .base.cra_driver_name   = name "-lib",                  \
                .base.cra_priority      = 300,                          \
                .base.cra_flags         = CRYPTO_ALG_OPTIONAL_KEY,      \
                .base.cra_blocksize     = BLAKE2B_BLOCK_SIZE,           \
                .base.cra_ctxsize       = sizeof(struct blake2b_tfm_ctx), \
                .base.cra_module        = THIS_MODULE,                  \
                .digestsize             = digest_size,                  \
                .setkey                 = crypto_blake2b_setkey,        \
                .init                   = crypto_blake2b_init,          \
                .update                 = crypto_blake2b_update,        \
                .final                  = crypto_blake2b_final,         \
                .digest                 = crypto_blake2b_digest,        \
                .descsize               = sizeof(struct blake2b_ctx),   \
        }

static struct shash_alg algs[] = {
        BLAKE2B_ALG("blake2b-160", BLAKE2B_160_HASH_SIZE),
        BLAKE2B_ALG("blake2b-256", BLAKE2B_256_HASH_SIZE),
        BLAKE2B_ALG("blake2b-384", BLAKE2B_384_HASH_SIZE),
        BLAKE2B_ALG("blake2b-512", BLAKE2B_512_HASH_SIZE),
};

static int __init crypto_blake2b_mod_init(void)
{
        return crypto_register_shashes(algs, ARRAY_SIZE(algs));
}
module_init(crypto_blake2b_mod_init);

static void __exit crypto_blake2b_mod_exit(void)
{
        crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
}
module_exit(crypto_blake2b_mod_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Crypto API support for BLAKE2b");

MODULE_ALIAS_CRYPTO("blake2b-160");
MODULE_ALIAS_CRYPTO("blake2b-160-lib");
MODULE_ALIAS_CRYPTO("blake2b-256");
MODULE_ALIAS_CRYPTO("blake2b-256-lib");
MODULE_ALIAS_CRYPTO("blake2b-384");
MODULE_ALIAS_CRYPTO("blake2b-384-lib");
MODULE_ALIAS_CRYPTO("blake2b-512");
MODULE_ALIAS_CRYPTO("blake2b-512-lib");