/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
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* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <sys/zfs_context.h>
#include <sys/crypto/common.h>
#include <sys/crypto/api.h>
#include <sys/crypto/impl.h>
/* Cryptographic mechanisms tables and their access functions */
/*
* Internal numbers assigned to mechanisms are coded as follows:
*
* +----------------+----------------+
* | mech. class | mech. index |
* <--- 32-bits --->+<--- 32-bits --->
*
* the mech_class identifies the table the mechanism belongs to.
* mech_index is the index for that mechanism in the table.
* A mechanism belongs to exactly 1 table.
* The tables are:
* . digest_mechs_tab[] for the msg digest mechs.
* . cipher_mechs_tab[] for encrypt/decrypt and wrap/unwrap mechs.
* . mac_mechs_tab[] for MAC mechs.
* . sign_mechs_tab[] for sign & verify mechs.
* . keyops_mechs_tab[] for key/key pair generation, and key derivation.
* . misc_mechs_tab[] for mechs that don't belong to any of the above.
*
* There are no holes in the tables.
*/
/*
* Locking conventions:
* --------------------
* A mutex is associated with every entry of the tables.
* The mutex is acquired whenever the entry is accessed for
* 1) retrieving the mech_id (comparing the mech name)
* 2) finding a provider for an xxx_init() or atomic operation.
* 3) altering the mechs entry to add or remove a provider.
*
* In 2), after a provider is chosen, its prov_desc is held and the
* entry's mutex must be dropped. The provider's working function (SPI) is
* called outside the mech_entry's mutex.
*
* The number of providers for a particular mechanism is not expected to be
* long enough to justify the cost of using rwlocks, so the per-mechanism
* entry mutex won't be very *hot*.
*
*/
/* Mechanisms tables */
/* RFE 4687834 Will deal with the extensibility of these tables later */
static kcf_mech_entry_t kcf_digest_mechs_tab[KCF_MAXDIGEST];
static kcf_mech_entry_t kcf_cipher_mechs_tab[KCF_MAXCIPHER];
static kcf_mech_entry_t kcf_mac_mechs_tab[KCF_MAXMAC];
const kcf_mech_entry_tab_t kcf_mech_tabs_tab[KCF_LAST_OPSCLASS + 1] = {
{0, NULL}, /* No class zero */
{KCF_MAXDIGEST, kcf_digest_mechs_tab},
{KCF_MAXCIPHER, kcf_cipher_mechs_tab},
{KCF_MAXMAC, kcf_mac_mechs_tab},
};
static avl_tree_t kcf_mech_hash;
static int
kcf_mech_hash_compar(const void *lhs, const void *rhs)
{
const kcf_mech_entry_t *l = lhs, *r = rhs;
int cmp = strncmp(l->me_name, r->me_name, CRYPTO_MAX_MECH_NAME);
return ((0 < cmp) - (cmp < 0));
}
void
kcf_destroy_mech_tabs(void)
{
for (void *cookie = NULL; avl_destroy_nodes(&kcf_mech_hash, &cookie); )
;
avl_destroy(&kcf_mech_hash);
}
/*
* kcf_init_mech_tabs()
*
* Called by the misc/kcf's _init() routine to initialize the tables
* of mech_entry's.
*/
void
kcf_init_mech_tabs(void)
{
avl_create(&kcf_mech_hash, kcf_mech_hash_compar,
sizeof (kcf_mech_entry_t), offsetof(kcf_mech_entry_t, me_node));
}
/*
* kcf_create_mech_entry()
*
* Arguments:
* . The class of mechanism.
* . the name of the new mechanism.
*
* Description:
* Creates a new mech_entry for a mechanism not yet known to the
* framework.
* This routine is called by kcf_add_mech_provider, which is
* in turn invoked for each mechanism supported by a provider.
* The'class' argument depends on the crypto_func_group_t bitmask
* in the registering provider's mech_info struct for this mechanism.
* When there is ambiguity in the mapping between the crypto_func_group_t
* and a class (dual ops, ...) the KCF_MISC_CLASS should be used.
*
* Context:
* User context only.
*
* Returns:
* KCF_INVALID_MECH_CLASS or KCF_INVALID_MECH_NAME if the class or
* the mechname is bogus.
* KCF_MECH_TAB_FULL when there is no room left in the mech. tabs.
* KCF_SUCCESS otherwise.
*/
static int
kcf_create_mech_entry(kcf_ops_class_t class, const char *mechname)
{
if ((class < KCF_FIRST_OPSCLASS) || (class > KCF_LAST_OPSCLASS))
return (KCF_INVALID_MECH_CLASS);
if ((mechname == NULL) || (mechname[0] == 0))
return (KCF_INVALID_MECH_NAME);
/*
* First check if the mechanism is already in one of the tables.
* The mech_entry could be in another class.
*/
avl_index_t where = 0;
kcf_mech_entry_t tmptab;
strlcpy(tmptab.me_name, mechname, CRYPTO_MAX_MECH_NAME);
if (avl_find(&kcf_mech_hash, &tmptab, &where) != NULL)
return (KCF_SUCCESS);
/* Now take the next unused mech entry in the class's tab */
kcf_mech_entry_t *me_tab = kcf_mech_tabs_tab[class].met_tab;
int size = kcf_mech_tabs_tab[class].met_size;
for (int i = 0; i < size; ++i)
if (me_tab[i].me_name[0] == 0) {
/* Found an empty spot */
strlcpy(me_tab[i].me_name, mechname,
CRYPTO_MAX_MECH_NAME);
me_tab[i].me_mechid = KCF_MECHID(class, i);
/* Add the new mechanism to the hash table */
avl_insert(&kcf_mech_hash, &me_tab[i], where);
return (KCF_SUCCESS);
}
return (KCF_MECH_TAB_FULL);
}
/*
* kcf_add_mech_provider()
*
* Arguments:
* . An index in to the provider mechanism array
* . A pointer to the provider descriptor
* . A storage for the kcf_prov_mech_desc_t the entry was added at.
*
* Description:
* Adds a new provider of a mechanism to the mechanism's mech_entry
* chain.
*
* Context:
* User context only.
*
* Returns
* KCF_SUCCESS on success
* KCF_MECH_TAB_FULL otherwise.
*/
int
kcf_add_mech_provider(short mech_indx,
kcf_provider_desc_t *prov_desc, kcf_prov_mech_desc_t **pmdpp)
{
int error;
kcf_mech_entry_t *mech_entry = NULL;
const crypto_mech_info_t *mech_info;
crypto_mech_type_t kcf_mech_type;
kcf_prov_mech_desc_t *prov_mech;
mech_info = &prov_desc->pd_mechanisms[mech_indx];
/*
* A mechanism belongs to exactly one mechanism table.
* Find the class corresponding to the function group flag of
* the mechanism.
*/
kcf_mech_type = crypto_mech2id(mech_info->cm_mech_name);
if (kcf_mech_type == CRYPTO_MECH_INVALID) {
crypto_func_group_t fg = mech_info->cm_func_group_mask;
kcf_ops_class_t class;
if (fg & CRYPTO_FG_DIGEST || fg & CRYPTO_FG_DIGEST_ATOMIC)
class = KCF_DIGEST_CLASS;
else if (fg & CRYPTO_FG_ENCRYPT || fg & CRYPTO_FG_DECRYPT ||
fg & CRYPTO_FG_ENCRYPT_ATOMIC ||
fg & CRYPTO_FG_DECRYPT_ATOMIC)
class = KCF_CIPHER_CLASS;
else if (fg & CRYPTO_FG_MAC || fg & CRYPTO_FG_MAC_ATOMIC)
class = KCF_MAC_CLASS;
else
__builtin_unreachable();
/*
* Attempt to create a new mech_entry for the specified
* mechanism. kcf_create_mech_entry() can handle the case
* where such an entry already exists.
*/
if ((error = kcf_create_mech_entry(class,
mech_info->cm_mech_name)) != KCF_SUCCESS) {
return (error);
}
/* get the KCF mech type that was assigned to the mechanism */
kcf_mech_type = crypto_mech2id(mech_info->cm_mech_name);
ASSERT(kcf_mech_type != CRYPTO_MECH_INVALID);
}
error = kcf_get_mech_entry(kcf_mech_type, &mech_entry);
ASSERT(error == KCF_SUCCESS);
/* allocate and initialize new kcf_prov_mech_desc */
prov_mech = kmem_zalloc(sizeof (kcf_prov_mech_desc_t), KM_SLEEP);
bcopy(mech_info, &prov_mech->pm_mech_info, sizeof (crypto_mech_info_t));
prov_mech->pm_prov_desc = prov_desc;
prov_desc->pd_mech_indx[KCF_MECH2CLASS(kcf_mech_type)]
[KCF_MECH2INDEX(kcf_mech_type)] = mech_indx;
KCF_PROV_REFHOLD(prov_desc);
KCF_PROV_IREFHOLD(prov_desc);
/*
* Add new kcf_prov_mech_desc at the front of HW providers
* chain.
*/
if (mech_entry->me_sw_prov != NULL) {
/*
* There is already a provider for this mechanism.
* Since we allow only one provider per mechanism,
* report this condition.
*/
cmn_err(CE_WARN, "The cryptographic provider "
"\"%s\" will not be used for %s. The provider "
"\"%s\" will be used for this mechanism "
"instead.", prov_desc->pd_description,
mech_info->cm_mech_name,
mech_entry->me_sw_prov->pm_prov_desc->
pd_description);
KCF_PROV_REFRELE(prov_desc);
kmem_free(prov_mech, sizeof (kcf_prov_mech_desc_t));
prov_mech = NULL;
} else {
/*
* Set the provider as the provider for
* this mechanism.
*/
mech_entry->me_sw_prov = prov_mech;
}
*pmdpp = prov_mech;
return (KCF_SUCCESS);
}
/*
* kcf_remove_mech_provider()
*
* Arguments:
* . mech_name: the name of the mechanism.
* . prov_desc: The provider descriptor
*
* Description:
* Removes a provider from chain of provider descriptors.
* The provider is made unavailable to kernel consumers for the specified
* mechanism.
*
* Context:
* User context only.
*/
void
kcf_remove_mech_provider(const char *mech_name, kcf_provider_desc_t *prov_desc)
{
crypto_mech_type_t mech_type;
kcf_prov_mech_desc_t *prov_mech = NULL;
kcf_mech_entry_t *mech_entry;
/* get the KCF mech type that was assigned to the mechanism */
if ((mech_type = crypto_mech2id(mech_name)) ==
CRYPTO_MECH_INVALID) {
/*
* Provider was not allowed for this mech due to policy or
* configuration.
*/
return;
}
/* get a ptr to the mech_entry that was created */
if (kcf_get_mech_entry(mech_type, &mech_entry) != KCF_SUCCESS) {
/*
* Provider was not allowed for this mech due to policy or
* configuration.
*/
return;
}
if (mech_entry->me_sw_prov == NULL ||
mech_entry->me_sw_prov->pm_prov_desc != prov_desc) {
/* not the provider for this mechanism */
return;
}
prov_mech = mech_entry->me_sw_prov;
mech_entry->me_sw_prov = NULL;
/* free entry */
KCF_PROV_REFRELE(prov_mech->pm_prov_desc);
KCF_PROV_IREFRELE(prov_mech->pm_prov_desc);
kmem_free(prov_mech, sizeof (kcf_prov_mech_desc_t));
}
/*
* kcf_get_mech_entry()
*
* Arguments:
* . The framework mechanism type
* . Storage for the mechanism entry
*
* Description:
* Retrieves the mechanism entry for the mech.
*
* Context:
* User and interrupt contexts.
*
* Returns:
* KCF_MECHANISM_XXX appropriate error code.
* KCF_SUCCESS otherwise.
*/
int
kcf_get_mech_entry(crypto_mech_type_t mech_type, kcf_mech_entry_t **mep)
{
kcf_ops_class_t class;
int index;
const kcf_mech_entry_tab_t *me_tab;
ASSERT(mep != NULL);
class = KCF_MECH2CLASS(mech_type);
if ((class < KCF_FIRST_OPSCLASS) || (class > KCF_LAST_OPSCLASS)) {
/* the caller won't need to know it's an invalid class */
return (KCF_INVALID_MECH_NUMBER);
}
me_tab = &kcf_mech_tabs_tab[class];
index = KCF_MECH2INDEX(mech_type);
if ((index < 0) || (index >= me_tab->met_size)) {
return (KCF_INVALID_MECH_NUMBER);
}
*mep = &((me_tab->met_tab)[index]);
return (KCF_SUCCESS);
}
/*
* crypto_mech2id()
*
* Arguments:
* . mechname: A null-terminated string identifying the mechanism name.
*
* Description:
* Walks the mechanisms tables, looking for an entry that matches the
* mechname. Once it find it, it builds the 64-bit mech_type and returns
* it.
*
* Context:
* Process and interruption.
*
* Returns:
* The unique mechanism identified by 'mechname', if found.
* CRYPTO_MECH_INVALID otherwise.
*/
/*
* Lookup the hash table for an entry that matches the mechname.
* If there are no providers for the mechanism,
* but there is an unloaded provider, this routine will attempt
* to load it.
*/
crypto_mech_type_t
crypto_mech2id(const char *mechname)
{
kcf_mech_entry_t tmptab, *found;
strlcpy(tmptab.me_name, mechname, CRYPTO_MAX_MECH_NAME);
if ((found = avl_find(&kcf_mech_hash, &tmptab, NULL))) {
ASSERT(found->me_mechid != CRYPTO_MECH_INVALID);
return (found->me_mechid);
}
return (CRYPTO_MECH_INVALID);
}
#if defined(_KERNEL)
EXPORT_SYMBOL(crypto_mech2id);
#endif