openssl/crypto/engine/eng_table.c
2001-09-26 11:38:57 +00:00

361 lines
12 KiB
C

/* ====================================================================
* Copyright (c) 2000 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include <openssl/evp.h>
#include <openssl/engine.h>
#include "eng_int.h"
/* This is the type of item in the 'implementation' table. Each 'nid' hashes to
* a (potentially NULL) ENGINE_PILE structure which contains a stack of ENGINE*
* pointers. These pointers aren't references, because they're inserted and
* removed during ENGINE creation and ENGINE destruction. They point to ENGINEs
* that *exist* (ie. have a structural reference count greater than zero) rather
* than ENGINEs that are *functional*. Each pointer in those stacks are to
* ENGINEs that implements the algorithm corresponding to each 'nid'. */
/* The type of the items in the table */
typedef struct st_engine_pile
{
/* The 'nid' of the algorithm/mode this ENGINE_PILE structure represents
* */
int nid;
/* A stack of ENGINE pointers for ENGINEs that support this
* algorithm/mode. In the event that 'funct' is NULL, the first entry in
* this stack that initialises will be set as 'funct' and assumed as the
* default for operations of this type. */
STACK_OF(ENGINE) *sk;
/* The default ENGINE to perform this algorithm/mode. */
ENGINE *funct;
/* This value optimises engine_table_select(). If it is called it sets
* this value to 1. Any changes to this ENGINE_PILE resets it to zero.
* As such, no ENGINE_init() thrashing is done unless ENGINEs
* continually register (and/or unregister). */
int uptodate;
} ENGINE_PILE;
/* The type of the hash table of ENGINE_PILE structures such that each are
* unique and keyed by the 'nid' value. */
struct st_engine_table
{
LHASH piles;
}; /* ENGINE_TABLE */
/* This value stores global options controlling behaviour of (mostly) the
* engine_table_select() function. It's a bitmask of flag values of the form
* ENGINE_TABLE_FLAG_*** (as defined in engine.h) and is controlled by the
* ENGINE_[get|set]_table_flags() function. */
static unsigned int table_flags = 0;
/* API function manipulating 'table_flags' */
unsigned int ENGINE_get_table_flags(void)
{
return table_flags;
}
void ENGINE_set_table_flags(unsigned int flags)
{
table_flags = flags;
}
/* Internal functions for the "piles" hash table */
static unsigned long engine_pile_hash(const ENGINE_PILE *c)
{
return c->nid;
}
static int engine_pile_cmp(const ENGINE_PILE *a, const ENGINE_PILE *b)
{
return a->nid - b->nid;
}
static IMPLEMENT_LHASH_HASH_FN(engine_pile_hash, const ENGINE_PILE *)
static IMPLEMENT_LHASH_COMP_FN(engine_pile_cmp, const ENGINE_PILE *)
static int int_table_check(ENGINE_TABLE **t, int create)
{
LHASH *lh;
if(*t)
return 1;
if(!create)
return 0;
if((lh = lh_new(LHASH_HASH_FN(engine_pile_hash),
LHASH_COMP_FN(engine_pile_cmp))) == NULL)
return 0;
*t = (ENGINE_TABLE *)lh;
return 1;
}
/* Privately exposed (via eng_int.h) functions for adding and/or removing
* ENGINEs from the implementation table */
int engine_table_register(ENGINE_TABLE **table, ENGINE_CLEANUP_CB cleanup,
ENGINE *e, const int *nids, int num_nids, int setdefault)
{
int ret = 0, added = 0;
ENGINE_PILE tmplate, *fnd;
CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
if(!(*table))
added = 1;
if(!int_table_check(table, 1))
goto end;
if(added)
/* The cleanup callback needs to be added */
engine_cleanup_add_first(cleanup);
while(num_nids--)
{
tmplate.nid = *nids;
fnd = lh_retrieve(&(*table)->piles, &tmplate);
if(!fnd)
{
fnd = OPENSSL_malloc(sizeof(ENGINE_PILE));
if(!fnd)
goto end;
fnd->uptodate = 1;
fnd->nid = *nids;
fnd->sk = sk_ENGINE_new_null();
if(!fnd->sk)
{
OPENSSL_free(fnd);
goto end;
}
fnd->funct= NULL;
lh_insert(&(*table)->piles, fnd);
}
/* A registration shouldn't add duplciate entries */
sk_ENGINE_delete_ptr(fnd->sk, e);
/* if 'setdefault', this ENGINE goes to the head of the list */
if(!sk_ENGINE_push(fnd->sk, e))
goto end;
/* "touch" this ENGINE_PILE */
fnd->uptodate = 0;
if(setdefault)
{
if(!engine_unlocked_init(e))
{
ENGINEerr(ENGINE_F_ENGINE_TABLE_REGISTER,
ENGINE_R_INIT_FAILED);
goto end;
}
if(fnd->funct)
engine_unlocked_finish(fnd->funct, 0);
fnd->funct = e;
}
nids++;
}
ret = 1;
end:
CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
return ret;
}
static void int_unregister_cb(ENGINE_PILE *pile, ENGINE *e)
{
int n;
/* Iterate the 'c->sk' stack removing any occurance of 'e' */
while((n = sk_ENGINE_find(pile->sk, e)) >= 0)
{
sk_ENGINE_delete(pile->sk, n);
/* "touch" this ENGINE_CIPHER */
pile->uptodate = 0;
}
if(pile->funct == e)
{
engine_unlocked_finish(e, 0);
pile->funct = NULL;
}
}
static IMPLEMENT_LHASH_DOALL_ARG_FN(int_unregister_cb,ENGINE_PILE *,ENGINE *)
void engine_table_unregister(ENGINE_TABLE **table, ENGINE *e)
{
CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
if(int_table_check(table, 0))
lh_doall_arg(&(*table)->piles,
LHASH_DOALL_ARG_FN(int_unregister_cb), e);
CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
}
static void int_cleanup_cb(ENGINE_PILE *p)
{
sk_ENGINE_free(p->sk);
if(p->funct)
engine_unlocked_finish(p->funct, 0);
OPENSSL_free(p);
}
static IMPLEMENT_LHASH_DOALL_FN(int_cleanup_cb,ENGINE_PILE *)
void engine_table_cleanup(ENGINE_TABLE **table)
{
CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
if(*table)
{
lh_doall(&(*table)->piles, LHASH_DOALL_FN(int_cleanup_cb));
lh_free(&(*table)->piles);
*table = NULL;
}
CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
}
/* Exposed API function to get a functional reference from the implementation
* table (ie. try to get a functional reference from the tabled structural
* references) for a given cipher 'nid' */
#ifndef ENGINE_TABLE_DEBUG
ENGINE *engine_table_select(ENGINE_TABLE **table, int nid)
#else
ENGINE *engine_table_select_tmp(ENGINE_TABLE **table, int nid, const char *f, int l)
#endif
{
ENGINE *ret = NULL;
ENGINE_PILE tmplate, *fnd=NULL;
int initres, loop = 0;
/* If 'engine_ciphers' is NULL, then it's absolutely *sure* that no
* ENGINEs have registered any implementations! */
if(!(*table))
{
#ifdef ENGINE_TABLE_DEBUG
fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, no "
"registered for anything!\n", f, l, nid);
#endif
return NULL;
}
CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
/* Check again inside the lock otherwise we could race against cleanup
* operations. But don't worry about a fprintf(stderr). */
if(!int_table_check(table, 0))
goto end;
tmplate.nid = nid;
fnd = lh_retrieve(&(*table)->piles, &tmplate);
if(!fnd)
goto end;
if(fnd->funct && engine_unlocked_init(fnd->funct))
{
#ifdef ENGINE_TABLE_DEBUG
fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
"ENGINE '%s' cached\n", f, l, nid, fnd->funct->id);
#endif
ret = fnd->funct;
goto end;
}
if(fnd->uptodate)
{
ret = fnd->funct;
goto end;
}
trynext:
ret = sk_ENGINE_value(fnd->sk, loop++);
if(!ret)
{
#ifdef ENGINE_TABLE_DEBUG
fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, no "
"registered implementations would initialise\n",
f, l, nid);
#endif
goto end;
}
#if 0
/* Don't need to get a reference if we hold the lock. If the locking has
* to change in future, that would be different ... */
ret->struct_ref++; engine_ref_debug(ret, 0, 1)
#endif
/* Try and initialise the ENGINE if it's already functional *or* if the
* ENGINE_TABLE_FLAG_NOINIT flag is not set. */
if((ret->funct_ref > 0) || !(table_flags & ENGINE_TABLE_FLAG_NOINIT))
initres = engine_unlocked_init(ret);
else
initres = 0;
#if 0
/* Release the structural reference */
ret->struct_ref--; engine_ref_debug(ret, 0, -1);
#endif
if(initres)
{
/* If we didn't have a default (functional reference) for this
* 'nid' (or we had one but for whatever reason we're now
* initialising a different one), use this opportunity to set
* 'funct'. */
if((fnd->funct != ret) && engine_unlocked_init(ret))
{
/* If there was a previous default we release it. */
if(fnd->funct)
engine_unlocked_finish(fnd->funct, 0);
/* We got an extra functional reference for the
* per-'nid' default */
fnd->funct = ret;
#ifdef ENGINE_TABLE_DEBUG
fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, "
"setting default to '%s'\n", f, l, nid, ret->id);
#endif
}
#ifdef ENGINE_TABLE_DEBUG
fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
"newly initialised '%s'\n", f, l, nid, ret->id);
#endif
goto end;
}
goto trynext;
end:
/* Whatever happened - we should "untouch" our uptodate file seeing as
* we have tried our best to find a functional reference for 'nid'. If
* it failed, it is unlikely to succeed again until some future
* registrations (or unregistrations) have taken place that affect that
* 'nid'. */
if(fnd)
fnd->uptodate = 1;
#ifdef ENGINE_TABLE_DEBUG
if(ret)
fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
"ENGINE '%s'\n", f, l, nid, ret->id);
else
fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
"'no matching ENGINE'\n", f, l, nid);
#endif
CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
/* Whatever happened, any failed init()s are not failures in this
* context, so clear our error state. */
ERR_clear_error();
return ret;
}