This patch adds an interface to wrap aead algorithms with an
arbitrary crypto template. This is useful to make a certain
version of an aead algorithm the system default of that algorithm.
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
---
crypto/aead.c | 286 +++++++++++++++++++++++++++++++++++++++-
include/crypto/internal/aead.h | 8 +
include/linux/crypto.h | 10 +-
3 files changed, 295 insertions(+), 9 deletions(-)
diff --git a/crypto/aead.c b/crypto/aead.c
index d9aa733..f45e27a 100644
--- a/crypto/aead.c
+++ b/crypto/aead.c
@@ -286,6 +286,7 @@ struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
+ inst->alg.cra_aead.wrapper = alg->cra_aead.wrapper;
inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
@@ -407,6 +408,262 @@ out:
return err;
}
+static int crypto_init_wrapaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
+{
+ struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
+ struct aead_tfm *crt = &tfm->crt_aead;
+
+ if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
+ return -EINVAL;
+
+ crt->setkey = alg->setkey;
+ crt->encrypt = alg->encrypt;
+ crt->decrypt = alg->decrypt;
+ crt->givencrypt = alg->givencrypt ?: no_givcrypt;
+ crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
+ crt->base = __crypto_aead_cast(tfm);
+ crt->ivsize = alg->ivsize;
+ crt->authsize = alg->maxauthsize;
+
+ return 0;
+}
+
+static void crypto_wrapaead_show(struct seq_file *m, struct crypto_alg *alg)
+ __attribute__ ((unused));
+static void crypto_wrapaead_show(struct seq_file *m, struct crypto_alg *alg)
+{
+ struct aead_alg *aead = &alg->cra_aead;
+
+ seq_printf(m, "type : wrapped aead\n");
+ seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
+ "yes" : "no");
+ seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
+ seq_printf(m, "ivsize : %u\n", aead->ivsize);
+ seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
+ seq_printf(m, "geniv : %s\n", aead->geniv ?: "<built-in>");
+ seq_printf(m, "wrapper : %s\n", alg->cra_flags & CRYPTO_ALG_WRAP ?
+ aead->wrapper : "<built-in>");
+}
+
+const struct crypto_type crypto_wrapaead_type = {
+ .ctxsize = crypto_aead_ctxsize,
+ .init = crypto_init_wrapaead_ops,
+#ifdef CONFIG_PROC_FS
+ .show = crypto_wrapaead_show,
+#endif
+};
+EXPORT_SYMBOL_GPL(crypto_wrapaead_type);
+
+static int crypto_grab_wrapaead(struct crypto_aead_spawn *spawn,
+ const char *name, u32 type, u32 mask)
+{
+ struct crypto_alg *alg;
+ int err;
+
+ type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_WRAP);
+ type |= CRYPTO_ALG_TYPE_AEAD;
+ mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_WRAP;
+
+ alg = crypto_alg_mod_lookup(name, type, mask);
+ if (IS_ERR(alg))
+ return PTR_ERR(alg);
+
+ err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
+ crypto_mod_put(alg);
+ return err;
+}
+
+struct crypto_instance *aead_wrap_alloc(struct crypto_template *tmpl,
+ struct rtattr **tb,
+ unsigned int ctx_size, u32 type,
+ u32 mask)
+{
+ const char *name;
+ struct crypto_aead_spawn *spawn;
+ struct crypto_attr_type *algt;
+ struct crypto_instance *inst;
+ struct crypto_alg *alg;
+ int err;
+
+ algt = crypto_get_attr_type(tb);
+ err = PTR_ERR(algt);
+ if (IS_ERR(algt))
+ return ERR_PTR(err);
+
+ if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_WRAP)) &
+ algt->mask)
+ return ERR_PTR(-EINVAL);
+
+ name = crypto_attr_alg_name(tb[1]);
+ err = PTR_ERR(name);
+ if (IS_ERR(name))
+ return ERR_PTR(err);
+
+ inst = kzalloc(sizeof(*inst) + ctx_size, GFP_KERNEL);
+ if (!inst)
+ return ERR_PTR(-ENOMEM);
+
+ spawn = crypto_instance_ctx(inst);
+
+ /* Ignore async algorithms if necessary. */
+ mask |= crypto_requires_sync(algt->type, algt->mask);
+
+ crypto_set_aead_spawn(spawn, inst);
+ err = crypto_grab_wrapaead(spawn, name, type, mask);
+ if (err)
+ goto err_free_inst;
+
+ alg = crypto_aead_spawn_alg(spawn);
+
+ err = -EINVAL;
+ if (alg->cra_type != &crypto_aead_type)
+ goto err_drop_alg;
+
+ if (algt->mask & CRYPTO_ALG_WRAP) {
+ if (strcmp(tmpl->name, alg->cra_aead.wrapper))
+ goto err_drop_alg;
+
+ memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
+ memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
+ CRYPTO_MAX_ALG_NAME);
+ } else {
+ err = -ENAMETOOLONG;
+ if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
+ "%s(%s)", tmpl->name, alg->cra_name) >=
+ CRYPTO_MAX_ALG_NAME)
+ goto err_drop_alg;
+ if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+ "%s(%s)", tmpl->name, alg->cra_driver_name) >=
+ CRYPTO_MAX_ALG_NAME)
+ goto err_drop_alg;
+ }
+
+ inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_WRAP;
+ inst->alg.cra_flags |= alg->cra_flags
+ & (CRYPTO_ALG_GENIV | CRYPTO_ALG_ASYNC);
+ inst->alg.cra_blocksize = alg->cra_blocksize;
+ inst->alg.cra_alignmask = alg->cra_alignmask;
+ inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
+ inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
+ inst->alg.cra_type = &crypto_wrapaead_type;
+ inst->alg.cra_aead.wrapper = alg->cra_aead.wrapper;
+ inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
+ inst->alg.cra_priority = alg->cra_priority + 100;
+
+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_wrap_alloc);
+
+void aead_wrap_free(struct crypto_instance *inst)
+{
+ crypto_drop_aead(crypto_instance_ctx(inst));
+ kfree(inst);
+}
+EXPORT_SYMBOL_GPL(aead_wrap_free);
+
+int aead_wrap_init(struct crypto_tfm *tfm)
+{
+ struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
+ struct crypto_aead *aead;
+
+ aead = crypto_spawn_aead(crypto_instance_ctx(inst));
+ if (IS_ERR(aead))
+ return PTR_ERR(aead);
+
+ tfm->crt_aead.base = aead;
+ tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(aead_wrap_init);
+
+void aead_wrap_exit(struct crypto_tfm *tfm)
+{
+ crypto_free_aead(tfm->crt_aead.base);
+}
+EXPORT_SYMBOL_GPL(aead_wrap_exit);
+
+static int crypto_wrapaead_default(struct crypto_alg *alg, u32 type, u32 mask)
+{
+ struct rtattr *tb[3];
+ struct {
+ struct rtattr attr;
+ struct crypto_attr_type data;
+ } ptype;
+ struct {
+ struct rtattr attr;
+ struct crypto_attr_alg data;
+ } palg;
+ struct crypto_template *tmpl;
+ struct crypto_instance *inst;
+ struct crypto_alg *larval;
+ const char *wrapper;
+ int err;
+
+ larval = crypto_larval_lookup(alg->cra_driver_name,
+ CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_WRAP,
+ CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_WRAP);
+ err = PTR_ERR(larval);
+ if (IS_ERR(larval))
+ goto out;
+
+ err = -EAGAIN;
+ if (!crypto_is_larval(larval))
+ goto drop_larval;
+
+ ptype.attr.rta_len = sizeof(ptype);
+ ptype.attr.rta_type = CRYPTOA_TYPE;
+ ptype.data.type = type | CRYPTO_ALG_WRAP;
+ ptype.data.mask = mask | CRYPTO_ALG_WRAP;
+ tb[0] = &ptype.attr;
+
+ palg.attr.rta_len = sizeof(palg);
+ palg.attr.rta_type = CRYPTOA_ALG;
+ /* Must use the exact name to locate ourselves. */
+ memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
+ tb[1] = &palg.attr;
+
+ tb[2] = NULL;
+
+ wrapper = alg->cra_aead.wrapper;
+
+ tmpl = crypto_lookup_template(wrapper);
+ err = -ENOENT;
+ if (!tmpl)
+ goto kill_larval;
+
+ inst = tmpl->alloc(tb);
+ err = PTR_ERR(inst);
+ if (IS_ERR(inst))
+ goto put_tmpl;
+
+ if ((err = crypto_register_instance(tmpl, inst))) {
+ tmpl->free(inst);
+ goto put_tmpl;
+ }
+
+ /* Redo the lookup to use the instance we just registered. */
+ err = -EAGAIN;
+
+put_tmpl:
+ crypto_tmpl_put(tmpl);
+kill_larval:
+ crypto_larval_kill(larval);
+drop_larval:
+ crypto_mod_put(larval);
+out:
+ crypto_mod_put(alg);
+ return err;
+}
+
static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
u32 mask)
{
@@ -416,10 +673,13 @@ static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
if (IS_ERR(alg))
return alg;
- if (alg->cra_type == &crypto_aead_type)
+ if (alg->cra_type == &crypto_wrapaead_type)
return alg;
- if (!alg->cra_aead.ivsize)
+ if ((alg->cra_type == &crypto_aead_type) && !alg->cra_aead.wrapper)
+ return alg;
+
+ if (!alg->cra_aead.ivsize && !alg->cra_aead.wrapper)
return alg;
crypto_mod_put(alg);
@@ -428,7 +688,7 @@ static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
if (IS_ERR(alg))
return alg;
- if (alg->cra_type == &crypto_aead_type) {
+ if (alg->cra_type == &crypto_wrapaead_type) {
if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
crypto_mod_put(alg);
alg = ERR_PTR(-ENOENT);
@@ -436,6 +696,18 @@ static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
return alg;
}
+ if (alg->cra_type == &crypto_aead_type) {
+ if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
+ crypto_mod_put(alg);
+ alg = ERR_PTR(-ENOENT);
+ }
+
+ if (!alg->cra_aead.wrapper)
+ return alg;
+
+ return ERR_PTR(crypto_wrapaead_default(alg, type, mask));
+ }
+
BUG_ON(!alg->cra_aead.ivsize);
return ERR_PTR(crypto_nivaead_default(alg, type, mask));
@@ -447,9 +719,9 @@ int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
struct crypto_alg *alg;
int err;
- type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
+ type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV | CRYPTO_ALG_WRAP);
type |= CRYPTO_ALG_TYPE_AEAD;
- mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
+ mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV | CRYPTO_ALG_WRAP);
mask |= CRYPTO_ALG_TYPE_MASK;
alg = crypto_lookup_aead(name, type, mask);
@@ -467,9 +739,9 @@ struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
struct crypto_tfm *tfm;
int err;
- type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
+ type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV | CRYPTO_ALG_WRAP);
type |= CRYPTO_ALG_TYPE_AEAD;
- mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
+ mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV | CRYPTO_ALG_WRAP);
mask |= CRYPTO_ALG_TYPE_MASK;
for (;;) {
diff --git a/include/crypto/internal/aead.h b/include/crypto/internal/aead.h
index d838c94..4bf8a50 100644
--- a/include/crypto/internal/aead.h
+++ b/include/crypto/internal/aead.h
@@ -65,6 +65,14 @@ static inline struct crypto_aead *aead_geniv_base(struct crypto_aead *geniv)
return crypto_aead_crt(geniv)->base;
}
+struct crypto_instance *aead_wrap_alloc(struct crypto_template *tmpl,
+ struct rtattr **tb,
+ unsigned int ctx_size, u32 type,
+ u32 mask);
+void aead_wrap_free(struct crypto_instance *inst);
+int aead_wrap_init(struct crypto_tfm *tfm);
+void aead_wrap_exit(struct crypto_tfm *tfm);
+
static inline void *aead_givcrypt_reqctx(struct aead_givcrypt_request *req)
{
return aead_request_ctx(&req->areq);
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index ec29fa2..2548bf0 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -71,6 +71,8 @@
#define CRYPTO_ALG_TESTED 0x00000400
+#define CRYPTO_ALG_WRAP 0x00000800
+
/*
* Transform masks and values (for crt_flags).
*/
@@ -242,6 +244,7 @@ struct aead_alg {
int (*givdecrypt)(struct aead_givcrypt_request *req);
const char *geniv;
+ const char *wrapper;
unsigned int ivsize;
unsigned int maxauthsize;
@@ -881,9 +884,12 @@ static inline unsigned int crypto_aead_reqsize(struct crypto_aead *tfm)
}
static inline void aead_request_set_tfm(struct aead_request *req,
- struct crypto_aead *tfm)
+ struct crypto_aead *aead)
{
- req->base.tfm = crypto_aead_tfm(crypto_aead_crt(tfm)->base);
+ struct crypto_tfm *tfm = crypto_aead_tfm(aead);
+
+ req->base.tfm = tfm->__crt_alg->cra_flags & CRYPTO_ALG_WRAP ?
+ tfm : crypto_aead_tfm(crypto_aead_crt(aead)->base);
}
static inline struct aead_request *aead_request_alloc(struct crypto_aead *tfm,
--
1.5.4.2
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