1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * geniv: Shared IV generator code
5 * This file provides common code to IV generators such as seqiv.
7 * Copyright (c) 2007-2019 Herbert Xu <herbert@gondor.apana.org.au>
10 #include <crypto/internal/geniv.h>
11 #include <crypto/internal/rng.h>
12 #include <crypto/null.h>
13 #include <linux/err.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/rtnetlink.h>
17 #include <linux/slab.h>
19 static int aead_geniv_setkey(struct crypto_aead *tfm,
20 const u8 *key, unsigned int keylen)
22 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
24 return crypto_aead_setkey(ctx->child, key, keylen);
27 static int aead_geniv_setauthsize(struct crypto_aead *tfm,
28 unsigned int authsize)
30 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
32 return crypto_aead_setauthsize(ctx->child, authsize);
35 static void aead_geniv_free(struct aead_instance *inst)
37 crypto_drop_aead(aead_instance_ctx(inst));
41 struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
42 struct rtattr **tb, u32 type, u32 mask)
44 struct crypto_aead_spawn *spawn;
45 struct crypto_attr_type *algt;
46 struct aead_instance *inst;
49 unsigned int maxauthsize;
52 algt = crypto_get_attr_type(tb);
54 return ERR_CAST(algt);
56 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
57 return ERR_PTR(-EINVAL);
59 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
61 return ERR_PTR(-ENOMEM);
63 spawn = aead_instance_ctx(inst);
65 /* Ignore async algorithms if necessary. */
66 mask |= crypto_requires_sync(algt->type, algt->mask);
68 err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
69 crypto_attr_alg_name(tb[1]), type, mask);
73 alg = crypto_spawn_aead_alg(spawn);
75 ivsize = crypto_aead_alg_ivsize(alg);
76 maxauthsize = crypto_aead_alg_maxauthsize(alg);
79 if (ivsize < sizeof(u64))
83 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
84 "%s(%s)", tmpl->name, alg->base.cra_name) >=
87 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
88 "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
92 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
93 inst->alg.base.cra_priority = alg->base.cra_priority;
94 inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
95 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
96 inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
98 inst->alg.setkey = aead_geniv_setkey;
99 inst->alg.setauthsize = aead_geniv_setauthsize;
101 inst->alg.ivsize = ivsize;
102 inst->alg.maxauthsize = maxauthsize;
104 inst->free = aead_geniv_free;
110 aead_geniv_free(inst);
114 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
116 int aead_init_geniv(struct crypto_aead *aead)
118 struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
119 struct aead_instance *inst = aead_alg_instance(aead);
120 struct crypto_aead *child;
123 spin_lock_init(&ctx->lock);
125 err = crypto_get_default_rng();
129 err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
130 crypto_aead_ivsize(aead));
131 crypto_put_default_rng();
135 ctx->sknull = crypto_get_default_null_skcipher();
136 err = PTR_ERR(ctx->sknull);
137 if (IS_ERR(ctx->sknull))
140 child = crypto_spawn_aead(aead_instance_ctx(inst));
141 err = PTR_ERR(child);
146 crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
147 sizeof(struct aead_request));
155 crypto_put_default_null_skcipher();
158 EXPORT_SYMBOL_GPL(aead_init_geniv);
160 void aead_exit_geniv(struct crypto_aead *tfm)
162 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
164 crypto_free_aead(ctx->child);
165 crypto_put_default_null_skcipher();
167 EXPORT_SYMBOL_GPL(aead_exit_geniv);
169 MODULE_LICENSE("GPL");
170 MODULE_DESCRIPTION("Shared IV generator code");