diff options
Diffstat (limited to 'crypto/geniv.c')
| -rw-r--r-- | crypto/geniv.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/crypto/geniv.c b/crypto/geniv.c new file mode 100644 index 000000000..bee4621b4 --- /dev/null +++ b/crypto/geniv.c @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * geniv: Shared IV generator code + * + * This file provides common code to IV generators such as seqiv. + * + * Copyright (c) 2007-2019 Herbert Xu <herbert@gondor.apana.org.au> + */ + +#include <crypto/internal/geniv.h> +#include <crypto/internal/rng.h> +#include <crypto/null.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/rtnetlink.h> +#include <linux/slab.h> + +static int aead_geniv_setkey(struct crypto_aead *tfm, + const u8 *key, unsigned int keylen) +{ + struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm); + + return crypto_aead_setkey(ctx->child, key, keylen); +} + +static int aead_geniv_setauthsize(struct crypto_aead *tfm, + unsigned int authsize) +{ + struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm); + + return crypto_aead_setauthsize(ctx->child, authsize); +} + +static void aead_geniv_free(struct aead_instance *inst) +{ + crypto_drop_aead(aead_instance_ctx(inst)); + kfree(inst); +} + +struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl, + struct rtattr **tb) +{ + struct crypto_aead_spawn *spawn; + struct aead_instance *inst; + struct aead_alg *alg; + unsigned int ivsize; + unsigned int maxauthsize; + u32 mask; + int err; + + err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); + if (err) + return ERR_PTR(err); + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return ERR_PTR(-ENOMEM); + + spawn = aead_instance_ctx(inst); + + err = crypto_grab_aead(spawn, aead_crypto_instance(inst), + crypto_attr_alg_name(tb[1]), 0, mask); + if (err) + goto err_free_inst; + + alg = crypto_spawn_aead_alg(spawn); + + ivsize = crypto_aead_alg_ivsize(alg); + maxauthsize = crypto_aead_alg_maxauthsize(alg); + + err = -EINVAL; + if (ivsize < sizeof(u64)) + goto err_free_inst; + + err = -ENAMETOOLONG; + if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, + "%s(%s)", tmpl->name, alg->base.cra_name) >= + CRYPTO_MAX_ALG_NAME) + goto err_free_inst; + if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "%s(%s)", tmpl->name, alg->base.cra_driver_name) >= + CRYPTO_MAX_ALG_NAME) + goto err_free_inst; + + inst->alg.base.cra_priority = alg->base.cra_priority; + inst->alg.base.cra_blocksize = alg->base.cra_blocksize; + inst->alg.base.cra_alignmask = alg->base.cra_alignmask; + inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx); + + inst->alg.setkey = aead_geniv_setkey; + inst->alg.setauthsize = aead_geniv_setauthsize; + + inst->alg.ivsize = ivsize; + inst->alg.maxauthsize = maxauthsize; + + inst->free = aead_geniv_free; + +out: + return inst; + +err_free_inst: + aead_geniv_free(inst); + inst = ERR_PTR(err); + goto out; +} +EXPORT_SYMBOL_GPL(aead_geniv_alloc); + +int aead_init_geniv(struct crypto_aead *aead) +{ + struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead); + struct aead_instance *inst = aead_alg_instance(aead); + struct crypto_aead *child; + int err; + + spin_lock_init(&ctx->lock); + + err = crypto_get_default_rng(); + if (err) + goto out; + + err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt, + crypto_aead_ivsize(aead)); + crypto_put_default_rng(); + if (err) + goto out; + + ctx->sknull = crypto_get_default_null_skcipher(); + err = PTR_ERR(ctx->sknull); + if (IS_ERR(ctx->sknull)) + goto out; + + child = crypto_spawn_aead(aead_instance_ctx(inst)); + err = PTR_ERR(child); + if (IS_ERR(child)) + goto drop_null; + + ctx->child = child; + crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) + + sizeof(struct aead_request)); + + err = 0; + +out: + return err; + +drop_null: + crypto_put_default_null_skcipher(); + goto out; +} +EXPORT_SYMBOL_GPL(aead_init_geniv); + +void aead_exit_geniv(struct crypto_aead *tfm) +{ + struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm); + + crypto_free_aead(ctx->child); + crypto_put_default_null_skcipher(); +} +EXPORT_SYMBOL_GPL(aead_exit_geniv); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Shared IV generator code"); |