diff options
Diffstat (limited to 'crypto/geniv.c')
| -rw-r--r-- | crypto/geniv.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/crypto/geniv.c b/crypto/geniv.c new file mode 100644 index 000000000000..b9e45a2a98b5 --- /dev/null +++ b/crypto/geniv.c @@ -0,0 +1,176 @@ +// 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); +} + +struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl, + struct rtattr **tb, u32 type, u32 mask) +{ + const char *name; + struct crypto_aead_spawn *spawn; + struct crypto_attr_type *algt; + struct aead_instance *inst; + struct aead_alg *alg; + unsigned int ivsize; + unsigned int maxauthsize; + int err; + + algt = crypto_get_attr_type(tb); + if (IS_ERR(algt)) + return ERR_CAST(algt); + + if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) + return ERR_PTR(-EINVAL); + + name = crypto_attr_alg_name(tb[1]); + if (IS_ERR(name)) + return ERR_CAST(name); + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return ERR_PTR(-ENOMEM); + + spawn = aead_instance_ctx(inst); + + /* Ignore async algorithms if necessary. */ + mask |= crypto_requires_sync(algt->type, algt->mask); + + crypto_set_aead_spawn(spawn, aead_crypto_instance(inst)); + err = crypto_grab_aead(spawn, name, type, 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_drop_alg; + + 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_drop_alg; + 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_drop_alg; + + inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC; + 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; + +out: + return inst; + +err_drop_alg: + crypto_drop_aead(spawn); +err_free_inst: + kfree(inst); + inst = ERR_PTR(err); + goto out; +} +EXPORT_SYMBOL_GPL(aead_geniv_alloc); + +void aead_geniv_free(struct aead_instance *inst) +{ + crypto_drop_aead(aead_instance_ctx(inst)); + kfree(inst); +} +EXPORT_SYMBOL_GPL(aead_geniv_free); + +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"); |