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gnupg/kbx/backend-cache.c
Daniel Kahn Gillmor 0904b8ef34 Spelling cleanup. 
No functional changes, just fixing minor spelling issues.

---

Most of these were identified from the command line by running:

  codespell \
    --ignore-words-list fpr,stati,keyserver,keyservers,asign,cas,iff,ifset \
    --skip '*.po,ChangeLog*,help.*.txt,*.jpg,*.eps,*.pdf,*.png,*.gpg,*.asc' \
    doc g13 g10 kbx agent artwork scd tests tools am common dirmngr sm \
    NEWS README README.maint TODO

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2020-02-18 18:07:46 -05:00

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This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* backend-cache.c - Cache backend for keyboxd
* Copyright (C) 2019 g10 Code GmbH
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-3.0-or-later
*/
/*
* This cache backend is designed to be queried first and to deliver
* cached items (which may also be not-found). A set a maintenance
* functions is used used by the frontend to fill the cache.
* FIXME: Support x.509
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include "keyboxd.h"
#include "../common/i18n.h"
#include "../common/host2net.h"
#include "backend.h"
#include "keybox-defs.h"
/* Standard values for the number of buckets and the threshold we use
* to flush items. */
#define NO_OF_KEY_ITEM_BUCKETS 383
#define KEY_ITEMS_PER_BUCKET_THRESHOLD 40
#define NO_OF_BLOB_BUCKETS 383
#define BLOBS_PER_BUCKET_THRESHOLD 20
/* Our definition of the backend handle. */
struct backend_handle_s
{
enum database_types db_type; /* Always DB_TYPE_CACHE. */
unsigned int backend_id; /* Always the id the backend. */
};
/* The object holding a blob. */
typedef struct blob_s
{
struct blob_s *next;
enum pubkey_types pktype;
unsigned int refcount;
unsigned int usecount;
unsigned int datalen;
unsigned char *data; /* The actual data of length DATALEN. */
unsigned char ubid[UBID_LEN];
} *blob_t;
static blob_t *blob_table; /* Hash table with the blobs. */
static size_t blob_table_size; /* Number of allocated buckets. */
static unsigned int blob_table_threshold; /* Max. # of items per bucket. */
static unsigned int blob_table_added; /* Number of items added. */
static unsigned int blob_table_dropped; /* Number of items dropped. */
static blob_t blob_attic; /* List of freed blobs. */
/* A list item to blob data. This is so that a next operation on a
* cached key item can actually work. Things are complicated because
* we do not want to force caching all object before we get a next
* request from the client. To accomplish this we keep a flag
* indicating that the search needs to continue instead of delivering
* the previous item from the cache. */
typedef struct bloblist_s
{
struct bloblist_s *next;
unsigned int final_kid:1; /* The final blob for KID searches. */
unsigned int final_fpr:1; /* The final blob for FPR searches. */
unsigned int ubid_valid:1; /* The blobid below is valid. */
unsigned int subkey:1; /* The entry is for a subkey. */
unsigned int fprlen:8; /* The length of the fingerprint or 0. */
char fpr[32]; /* The buffer for the fingerprint. */
unsigned char ubid[UBID_LEN]; /* The Unique-Blob-ID of the blob. */
} *bloblist_t;
static bloblist_t bloblist_attic; /* List of freed items. */
/* The cache object. For indexing we could use the fingerprint
* directly as a hash value. However, we use the keyid instead
* because the keyid is used by OpenPGP in encrypted packets and older
* signatures to identify a key. Since v4 OpenPGP keys the keyid is
* anyway a part of the fingerprint so it quickly extracted from a
* fingerprint. Note that v3 keys are not supported by gpg.
* FIXME: Add support for X.509.
*/
typedef struct key_item_s
{
struct key_item_s *next;
bloblist_t blist; /* List of blobs or NULL for not-found. */
unsigned int usecount;
unsigned int refcount; /* Reference counter for this item. */
u32 kid_h; /* Upper 4 bytes of the keyid. */
u32 kid_l; /* Lower 4 bytes of the keyid. */
} *key_item_t;
static key_item_t *key_table; /* Hash table with the keys. */
static size_t key_table_size; /* Number of allocated buckets. */
static unsigned int key_table_threshold; /* Max. # of items per bucket. */
static unsigned int key_table_added; /* Number of items added. */
static unsigned int key_table_dropped; /* Number of items dropped. */
static key_item_t key_item_attic; /* List of freed items. */
/* The hash function we use for the key_table. Must not call a system
* function. */
static inline unsigned int
blob_table_hasher (const unsigned char *ubid)
{
return (ubid[0] << 16 | ubid[1]) % blob_table_size;
}
/* Runtime allocation of the key table. This allows us to eventually
* add an option to control the size. */
static gpg_error_t
blob_table_init (void)
{
if (blob_table)
return 0;
blob_table_size = NO_OF_BLOB_BUCKETS;
blob_table_threshold = BLOBS_PER_BUCKET_THRESHOLD;
blob_table = xtrycalloc (blob_table_size, sizeof *blob_table);
if (!blob_table)
return gpg_error_from_syserror ();
return 0;
}
/* Free a blob. This is done by moving it to the attic list. */
static void
blob_unref (blob_t blob)
{
void *p;
if (!blob)
return;
log_assert (blob->refcount);
if (!--blob->refcount)
{
p = blob->data;
blob->data = NULL;
blob->next = blob_attic;
blob_attic = blob;
xfree (p);
}
}
/* Given the hash value and the ubid, find the blob in the bucket.
* Returns NULL if not found or the blob item if found. Always
* returns the the number of items searched, which is in the case of a
* not-found the length of the chain. */
static blob_t
find_blob (unsigned int hash, const unsigned char *ubid,
unsigned int *r_count)
{
blob_t b;
unsigned int count = 0;
for (b = blob_table[hash]; b; b = b->next, count++)
if (!memcmp (b->ubid, ubid, UBID_LEN))
break;
if (r_count)
*r_count = count;
return b;
}
/* Helper for the qsort in key_table_put. */
static int
compare_blobs (const void *arg_a, const void *arg_b)
{
const blob_t a = *(const blob_t *)arg_a;
const blob_t b = *(const blob_t *)arg_b;
/* Reverse sort on the usecount. */
if (a->usecount > b->usecount)
return -1;
else if (a->usecount == b->usecount)
return 0;
else
return 1;
}
/* Put the blob (BLOBDATA, BLOBDATALEN) into the cache using UBID as
* the index. If it is already in the cache nothing happens. */
static void
blob_table_put (const unsigned char *ubid, enum pubkey_types pktype,
const void *blobdata, unsigned int blobdatalen)
{
unsigned int hash;
blob_t b;
unsigned int count, n;
void *blobdatacopy = NULL;
hash = blob_table_hasher (ubid);
find_again:
b = find_blob (hash, ubid, &count);
if (b)
{
xfree (blobdatacopy);
return; /* Already got this blob. */
}
/* Create a copy of the blob if not yet done. */
if (!blobdatacopy)
{
blobdatacopy = xtrymalloc (blobdatalen);
if (!blobdatacopy)
{
log_info ("Note: malloc failed while copying blob to the cache: %s\n",
gpg_strerror (gpg_error_from_syserror ()));
return; /* Out of core - ignore. */
}
memcpy (blobdatacopy, blobdata, blobdatalen);
}
/* If the bucket is full remove a couple of items. */
if (count >= blob_table_threshold)
{
blob_t list_head, *list_tailp, b_next;
blob_t *array;
int narray, idx;
/* Unlink from the global list so that other threads don't
* disturb us. If another thread adds or removes something only
* one will be the winner. Bad luck for the dropped cache items
* but after all it is just a cache. */
list_head = blob_table[hash];
blob_table[hash] = NULL;
/* Put all items into an array for sorting. */
array = xtrycalloc (count, sizeof *array);
if (!array)
{
/* That's bad; give up all items of the bucket. */
log_info ("Note: malloc failed while purging blobs from the "
"cache: %s\n", gpg_strerror (gpg_error_from_syserror ()));
goto leave_drop;
}
narray = 0;
for (b = list_head; b; b = b_next)
{
b_next = b->next;
array[narray++] = b;
b->next = NULL;
}
log_assert (narray == count);
/* Sort the array and put half of it onto a new list. */
qsort (array, narray, sizeof *array, compare_blobs);
list_head = NULL;
list_tailp = &list_head;
for (idx=0; idx < narray/2; idx++)
{
*list_tailp = array[idx];
list_tailp = &array[idx]->next;
}
/* Put the new list into the bucket. */
b = blob_table[hash];
blob_table[hash] = list_head;
list_head = b;
/* Free the remaining items and the array. */
for (; idx < narray; idx++)
{
blob_unref (array[idx]);
blob_table_dropped++;
}
xfree (array);
leave_drop:
/* Free any items added in the meantime by other threads. This
* is also used in case of a malloc problem (which won't update
* the counters, though). */
for ( ; list_head; list_head = b_next)
{
b_next = list_head->next;
blob_unref (list_head);
}
}
/* Add an item to the bucket. We allocate a whole block of items
* for cache performance reasons. */
if (!blob_attic)
{
blob_t b_block;
int b_blocksize = 256;
b_block = xtrymalloc (b_blocksize * sizeof *b_block);
if (!b_block)
{
log_info ("Note: malloc failed while adding blob to the cache: %s\n",
gpg_strerror (gpg_error_from_syserror ()));
xfree (blobdatacopy);
return; /* Out of core - ignore. */
}
for (n = 0; n < b_blocksize; n++)
{
b = b_block + n;
b->next = blob_attic;
blob_attic = b;
}
/* During the malloc another thread might have changed the
* bucket. Thus we need to start over. */
goto find_again;
}
/* We now know that there is an item in the attic. Put it into the
* chain. Note that we may not use any system call here. */
b = blob_attic;
blob_attic = b->next;
b->next = NULL;
b->pktype = pktype;
b->data = blobdatacopy;
b->datalen = blobdatalen;
memcpy (b->ubid, ubid, UBID_LEN);
b->usecount = 1;
b->refcount = 1;
b->next = blob_table[hash];
blob_table[hash] = b;
blob_table_added++;
}
/* Given the UBID return a cached blob item. The caller must
* release that item using blob_unref. */
static blob_t
blob_table_get (const unsigned char *ubid)
{
unsigned int hash;
blob_t b;
hash = blob_table_hasher (ubid);
b = find_blob (hash, ubid, NULL);
if (b)
{
b->usecount++;
b->refcount++;
return b; /* Found */
}
return NULL;
}
/* The hash function we use for the key_table. Must not call a system
* function. */
static inline unsigned int
key_table_hasher (u32 kid_l)
{
return kid_l % key_table_size;
}
/* Runtime allocation of the key table. This allows us to eventually
* add an option to control the size. */
static gpg_error_t
key_table_init (void)
{
if (key_table)
return 0;
key_table_size = NO_OF_KEY_ITEM_BUCKETS;
key_table_threshold = KEY_ITEMS_PER_BUCKET_THRESHOLD;
key_table = xtrycalloc (key_table_size, sizeof *key_table);
if (!key_table)
return gpg_error_from_syserror ();
return 0;
}
/* Free a key_item. This is done by moving it to the attic list. */
static void
key_item_unref (key_item_t ki)
{
bloblist_t bl, bl2;
if (!ki)
return;
log_assert (ki->refcount);
if (!--ki->refcount)
{
bl = ki->blist;
ki->blist = NULL;
ki->next = key_item_attic;
key_item_attic = ki;
if (bl)
{
for (bl2 = bl; bl2->next; bl2 = bl2->next)
;
bl2->next = bloblist_attic;
bloblist_attic = bl;
}
}
}
/* Given the hash value and the search info, find the key item in the
* bucket. Return NULL if not found or the key item if found. Always
* returns the the number of items searched, which is in the case of a
* not-found the length of the chain. Note that FPR may only be NULL
* if FPRLEN is 0. */
static key_item_t
find_in_chain (unsigned int hash, u32 kid_h, u32 kid_l,
unsigned int *r_count)
{
key_item_t ki = key_table[hash];
unsigned int count = 0;
for (; ki; ki = ki->next, count++)
if (ki->kid_h == kid_h && ki->kid_l == kid_l)
break;
if (r_count)
*r_count = count;
return ki;
}
/* Helper for the qsort in key_table_put. */
static int
compare_key_items (const void *arg_a, const void *arg_b)
{
const key_item_t a = *(const key_item_t *)arg_a;
const key_item_t b = *(const key_item_t *)arg_b;
/* Reverse sort on the usecount. */
if (a->usecount > b->usecount)
return -1;
else if (a->usecount == b->usecount)
return 0;
else
return 1;
}
/* Allocate new key items. They are put to the attic so that the
* caller can take them from there. On allocation failure a note
* is printed and an error returned. */
static gpg_error_t
alloc_more_key_items (void)
{
gpg_error_t err;
key_item_t kiblock, ki;
int kiblocksize = 256;
unsigned int n;
kiblock = xtrymalloc (kiblocksize * sizeof *kiblock);
if (!kiblock)
{
err = gpg_error_from_syserror ();
log_info ("Note: malloc failed while adding to the cache: %s\n",
gpg_strerror (err));
return err;
}
for (n = 0; n < kiblocksize; n++)
{
ki = kiblock + n;
ki->next = key_item_attic;
key_item_attic = ki;
}
return 0;
}
/* Allocate new bloblist items. They are put to the attic so that the
* caller can take them from there. On allocation failure a note is
* printed and an error returned. */
static gpg_error_t
alloc_more_bloblist_items (void)
{
gpg_error_t err;
bloblist_t bl;
bloblist_t blistblock;
int blistblocksize = 256;
unsigned int n;
blistblock = xtrymalloc (blistblocksize * sizeof *blistblock);
if (!blistblock)
{
err = gpg_error_from_syserror ();
log_info ("Note: malloc failed while adding to the cache: %s\n",
gpg_strerror (err));
return err;
}
for (n = 0; n < blistblocksize; n++)
{
bl = blistblock + n;
bl->next = bloblist_attic;
bloblist_attic = bl;
}
return 0;
}
/* Helper for key_table_put. This function assumes that
* bloblist_attaci is not NULL. Returns a new bloblist item. Be
* aware that no system calls may be done - even not log
* functions! */
static bloblist_t
new_bloblist_item (const unsigned char *fpr, unsigned int fprlen,
const unsigned char *ubid, int subkey)
{
bloblist_t bl;
bl = bloblist_attic;
bloblist_attic = bl->next;
bl->next = NULL;
if (ubid)
memcpy (bl->ubid, ubid, UBID_LEN);
else
memset (bl->ubid, 0, UBID_LEN);
bl->ubid_valid = 1;
bl->final_kid = 0;
bl->final_fpr = 0;
bl->subkey = !!subkey;
bl->fprlen = fprlen;
memcpy (bl->fpr, fpr, fprlen);
return bl;
}
/* If the list of key item in the bucken HASH is full remove a couple
* of them. On error a diagnostic is printed and an error code
* return. Note that the error code GPG_ERR_TRUE is returned if any
* flush and thus system calls were done.
*/
static gpg_error_t
maybe_flush_some_key_buckets (unsigned int hash, unsigned int count)
{
gpg_error_t err;
key_item_t ki, list_head, *list_tailp, ki_next;
key_item_t *array;
int narray, idx;
if (count < key_table_threshold)
return 0; /* Nothing to do. */
/* Unlink from the global list so that other threads don't disturb
* us. If another thread adds or removes something only one will be
* the winner. Bad luck for the dropped cache items but after all
* it is just a cache. */
list_head = key_table[hash];
key_table[hash] = NULL;
/* Put all items into an array for sorting. */
array = xtrycalloc (count, sizeof *array);
if (!array)
{
/* That's bad; give up all items of the bucket. */
err = gpg_error_from_syserror ();
log_info ("Note: malloc failed while purging from the cache: %s\n",
gpg_strerror (err));
goto leave;
}
narray = 0;
for (ki = list_head; ki; ki = ki_next)
{
ki_next = ki->next;
array[narray++] = ki;
ki->next = NULL;
}
log_assert (narray == count);
/* Sort the array and put half of it onto a new list. */
qsort (array, narray, sizeof *array, compare_key_items);
list_head = NULL;
list_tailp = &list_head;
for (idx=0; idx < narray/2; idx++)
{
*list_tailp = array[idx];
list_tailp = &array[idx]->next;
}
/* Put the new list into the bucket. */
ki = key_table[hash];
key_table[hash] = list_head;
list_head = ki;
/* Free the remaining items and the array. */
for (; idx < narray; idx++)
{
key_item_unref (array[idx]);
key_table_dropped++;
}
xfree (array);
err = gpg_error (GPG_ERR_TRUE);
leave:
/* Free any items added in the meantime by other threads. This is
* also used in case of a malloc problem (which won't update the
* counters, though). */
for ( ; list_head; list_head = ki_next)
{
ki_next = list_head->next;
key_item_unref (list_head);
}
return err;
}
/* This is the core of
* key_table_put,
* key_table_put_no_fpr,
* key_table_put_no_kid.
*/
static void
do_key_table_put (u32 kid_h, u32 kid_l,
const unsigned char *fpr, unsigned int fprlen,
const unsigned char *ubid, int subkey)
{
unsigned int hash;
key_item_t ki;
bloblist_t bl, bl_tail;
unsigned int count;
int do_find_again;
int mark_not_found = !fpr;
hash = key_table_hasher (kid_l);
find_again:
do_find_again = 0;
ki = find_in_chain (hash, kid_h, kid_l, &count);
if (ki)
{
if (mark_not_found)
return; /* Can't put the mark because meanwhile a entry was
* added. */
for (bl = ki->blist; bl; bl = bl->next)
if (bl->fprlen
&& bl->fprlen == fprlen
&& !memcmp (bl->fpr, fpr, fprlen))
break;
if (bl)
return; /* Already in the bloblist for the keyid */
/* Append to the list. */
if (!bloblist_attic)
{
if (alloc_more_bloblist_items ())
return; /* Out of core - ignore. */
goto find_again; /* Need to start over due to the malloc. */
}
for (bl_tail = NULL, bl = ki->blist; bl; bl_tail = bl, bl = bl->next)
;
bl = new_bloblist_item (fpr, fprlen, ubid, subkey);
if (bl_tail)
bl_tail->next = bl;
else
ki->blist = bl;
return;
}
/* If the bucket is full remove a couple of items. */
if (maybe_flush_some_key_buckets (hash, count))
{
/* During the function call another thread might have changed
* the bucket. Thus we need to start over. */
do_find_again = 1;
}
if (!key_item_attic)
{
if (alloc_more_key_items ())
return; /* Out of core - ignore. */
do_find_again = 1;
}
if (!bloblist_attic)
{
if (alloc_more_bloblist_items ())
return; /* Out of core - ignore. */
do_find_again = 1;
}
if (do_find_again)
goto find_again;
/* We now know that there are items in the attics. Put them into
* the chain. Note that we may not use any system call here. */
ki = key_item_attic;
key_item_attic = ki->next;
ki->next = NULL;
if (mark_not_found)
ki->blist = NULL;
else
ki->blist = new_bloblist_item (fpr, fprlen, ubid, subkey);
ki->kid_h = kid_h;
ki->kid_l = kid_l;
ki->usecount = 1;
ki->refcount = 1;
ki->next = key_table[hash];
key_table[hash] = ki;
key_table_added++;
}
/* Given the fingerprint (FPR,FPRLEN) put the UBID into the cache.
* SUBKEY indicates that the fingerprint is from a subkey. */
static void
key_table_put (const unsigned char *fpr, unsigned int fprlen,
const unsigned char *ubid, int subkey)
{
u32 kid_h, kid_l;
if (fprlen < 20 || fprlen > 32)
return; /* No support for v3 keys or unknown key versions. */
if (fprlen == 20) /* v4 key */
{
kid_h = buf32_to_u32 (fpr+12);
kid_l = buf32_to_u32 (fpr+16);
}
else /* v5 or later key */
{
kid_h = buf32_to_u32 (fpr);
kid_l = buf32_to_u32 (fpr+4);
}
do_key_table_put (kid_h, kid_l, fpr, fprlen, ubid, subkey);
}
/* Given the fingerprint (FPR,FPRLEN) put a flag into the cache that
* this fingerprint was not found. */
static void
key_table_put_no_fpr (const unsigned char *fpr, unsigned int fprlen)
{
u32 kid_h, kid_l;
if (fprlen < 20 || fprlen > 32)
return; /* No support for v3 keys or unknown key versions. */
if (fprlen == 20) /* v4 key */
{
kid_h = buf32_to_u32 (fpr+12);
kid_l = buf32_to_u32 (fpr+16);
}
else /* v5 or later key */
{
kid_h = buf32_to_u32 (fpr);
kid_l = buf32_to_u32 (fpr+4);
}
/* Note that our not-found chaching is only based on the keyid. */
do_key_table_put (kid_h, kid_l, NULL, 0, NULL, 0);
}
/* Given the keyid (KID_H, KID_L) put a flag into the cache that this
* keyid was not found. */
static void
key_table_put_no_kid (u32 kid_h, u32 kid_l)
{
do_key_table_put (kid_h, kid_l, NULL, 0, NULL, 0);
}
/* Given the keyid or the fingerprint return the key item from the
* cache. The caller must release the result using key_item_unref.
* NULL is returned if not found. */
static key_item_t
key_table_get (u32 kid_h, u32 kid_l)
{
unsigned int hash;
key_item_t ki;
hash = key_table_hasher (kid_l);
ki = find_in_chain (hash, kid_h, kid_l, NULL);
if (ki)
{
ki->usecount++;
ki->refcount++;
return ki; /* Found */
}
return NULL;
}
/* Return a key item by searching for the keyid. The caller must use
* key_item_unref on it. */
static key_item_t
query_by_kid (u32 kid_h, u32 kid_l)
{
return key_table_get (kid_h, kid_l);
}
/* Return a key item by searching for the fingerprint. The caller
* must use key_item_unref on it. Note that the returned key item may
* not actually carry the fingerprint; the caller needs to scan the
* bloblist of the keyitem. We can't do that here because the
* reference counting is done on the keyitem s and thus this needs to
* be returned. */
static key_item_t
query_by_fpr (const unsigned char *fpr, unsigned int fprlen)
{
u32 kid_h, kid_l;
if (fprlen < 20 || fprlen > 32 )
return NULL; /* No support for v3 keys or unknown key versions. */
if (fprlen == 20) /* v4 key */
{
kid_h = buf32_to_u32 (fpr+12);
kid_l = buf32_to_u32 (fpr+16);
}
else /* v5 or later key */
{
kid_h = buf32_to_u32 (fpr);
kid_l = buf32_to_u32 (fpr+4);
}
return key_table_get (kid_h, kid_l);
}
/* Make sure the tables are initialized. */
gpg_error_t
be_cache_initialize (void)
{
gpg_error_t err;
err = blob_table_init ();
if (!err)
err = key_table_init ();
return err;
}
/* Install a new resource and return a handle for that backend. */
gpg_error_t
be_cache_add_resource (ctrl_t ctrl, backend_handle_t *r_hd)
{
gpg_error_t err;
backend_handle_t hd;
(void)ctrl;
*r_hd = NULL;
hd = xtrycalloc (1, sizeof *hd);
if (!hd)
return gpg_error_from_syserror ();
hd->db_type = DB_TYPE_CACHE;
hd->backend_id = be_new_backend_id ();
/* Just in case make sure we are initialized. */
err = be_cache_initialize ();
if (err)
goto leave;
*r_hd = hd;
hd = NULL;
leave:
xfree (hd);
return err;
}
/* Release the backend handle HD and all its resources. HD is not
* valid after a call to this function. */
void
be_cache_release_resource (ctrl_t ctrl, backend_handle_t hd)
{
(void)ctrl;
if (!hd)
return;
hd->db_type = DB_TYPE_NONE;
/* Fixme: Free the key_table. */
xfree (hd);
}
/* Search for the keys described by (DESC,NDESC) and return them to
* the caller. BACKEND_HD is the handle for this backend and REQUEST
* is the current database request object. On a cache hit either 0 or
* GPG_ERR_NOT_FOUND is returned. The former returns the item; the
* latter indicates that the cache has known that the item won't be
* found in any databases. On a cache miss GPG_ERR_EOF is
* returned. */
gpg_error_t
be_cache_search (ctrl_t ctrl, backend_handle_t backend_hd, db_request_t request,
KEYDB_SEARCH_DESC *desc, unsigned int ndesc)
{
gpg_error_t err;
db_request_part_t reqpart;
unsigned int n;
blob_t b;
key_item_t ki;
bloblist_t bl;
int not_found = 0;
int descidx = 0;
int found_bykid = 0;
log_assert (backend_hd && backend_hd->db_type == DB_TYPE_CACHE);
log_assert (request);
err = be_find_request_part (backend_hd, request, &reqpart);
if (err)
goto leave;
if (!desc)
{
/* Reset operation. */
request->last_cached_valid = 0;
request->last_cached_final = 0;
reqpart->cache_seqno.fpr = 0;
reqpart->cache_seqno.kid = 0;
reqpart->cache_seqno.grip = 0;
reqpart->cache_seqno.ubid = 0;
err = 0;
goto leave;
}
for (ki = NULL, n=0; n < ndesc && !ki; n++)
{
descidx = n;
switch (desc[n].mode)
{
case KEYDB_SEARCH_MODE_LONG_KID:
ki = query_by_kid (desc[n].u.kid[0], desc[n].u.kid[1]);
if (ki && ki->blist)
{
not_found = 0;
/* Note that in a bloblist all keyids are the same. */
for (n=0, bl = ki->blist; bl; bl = bl->next)
if (n++ == reqpart->cache_seqno.kid)
break;
if (!bl)
{
key_item_unref (ki);
ki = NULL;
}
else
{
found_bykid = 1;
reqpart->cache_seqno.kid++;
}
}
else if (ki)
not_found = 1;
break;
case KEYDB_SEARCH_MODE_FPR:
ki = query_by_fpr (desc[n].u.fpr, desc[n].fprlen);
if (ki && ki->blist)
{
not_found = 0;
for (n=0, bl = ki->blist; bl; bl = bl->next)
if (bl->fprlen
&& bl->fprlen == desc[n].fprlen
&& !memcmp (bl->fpr, desc[n].u.fpr, desc[n].fprlen)
&& n++ == reqpart->cache_seqno.fpr)
break;
if (!bl)
{
key_item_unref (ki);
ki = NULL;
}
else
reqpart->cache_seqno.fpr++;
}
else if (ki)
not_found = 1;
break;
/* case KEYDB_SEARCH_MODE_KEYGRIP: */
/* ki = query_by_grip (desc[n].u.fpr, desc[n].fprlen); */
/* break; */
case KEYDB_SEARCH_MODE_UBID:
/* This is the quite special UBID mode: If this is
* encountered in the search list we will return just this
* one and obviously look only into the blob cache. */
if (reqpart->cache_seqno.ubid)
err = gpg_error (GPG_ERR_NOT_FOUND);
else
{
b = blob_table_get (desc[n].u.ubid);
if (b)
{
err = be_return_pubkey (ctrl, b->data, b->datalen,
b->pktype, desc[n].u.ubid);
blob_unref (b);
reqpart->cache_seqno.ubid++;
}
else
err = gpg_error (GPG_ERR_EOF);
}
goto leave;
default:
ki = NULL;
break;
}
}
if (not_found)
{
err = gpg_error (GPG_ERR_NOT_FOUND);
key_item_unref (ki);
}
else if (ki)
{
if (bl && bl->ubid_valid)
{
memcpy (request->last_cached_ubid, bl->ubid, UBID_LEN);
request->last_cached_valid = 1;
request->last_cached_fprlen = desc[descidx].fprlen;
memcpy (request->last_cached_fpr,
desc[descidx].u.fpr, desc[descidx].fprlen);
request->last_cached_kid_h = ki->kid_h;
request->last_cached_kid_l = ki->kid_l;
request->last_cached_valid = 1;
if ((bl->final_kid && found_bykid)
|| (bl->final_fpr && !found_bykid))
request->last_cached_final = 1;
else
request->last_cached_final = 0;
b = blob_table_get (bl->ubid);
if (b)
{
err = be_return_pubkey (ctrl, b->data, b->datalen,
PUBKEY_TYPE_OPGP, bl->ubid);
blob_unref (b);
}
else
{
/* FIXME - return a different code so that the caller
* can lookup using the UBID. */
err = gpg_error (GPG_ERR_MISSING_VALUE);
}
}
else if (bl)
err = gpg_error (GPG_ERR_MISSING_VALUE);
else
err = gpg_error (GPG_ERR_NOT_FOUND);
key_item_unref (ki);
}
else
err = gpg_error (GPG_ERR_EOF);
leave:
return err;
}
/* Mark the last cached item as the final item. This is called when
* the actual database returned EOF in respond to a restart from the
* last cached UBID. */
void
be_cache_mark_final (ctrl_t ctrl, db_request_t request)
{
key_item_t ki;
bloblist_t bl, blfound;
(void)ctrl;
log_assert (request);
if (!request->last_cached_valid)
return;
if (!request->last_cached_fprlen) /* Was cached via keyid. */
{
ki = query_by_kid (request->last_cached_kid_h,
request->last_cached_kid_l);
if (ki && (bl = ki->blist))
{
for (blfound=NULL; bl; bl = bl->next)
blfound = bl;
if (blfound)
blfound->final_kid = 1;
}
key_item_unref (ki);
}
else /* Was cached via fingerprint. */
{
ki = query_by_fpr (request->last_cached_fpr,
request->last_cached_fprlen);
if (ki && (bl = ki->blist))
{
for (blfound=NULL; bl; bl = bl->next)
if (bl->fprlen
&& bl->fprlen == request->last_cached_fprlen
&& !memcmp (bl->fpr, request->last_cached_fpr,
request->last_cached_fprlen))
blfound = bl;
if (blfound)
blfound->final_fpr = 1;
}
key_item_unref (ki);
}
request->last_cached_valid = 0;
}
/* Put the key (BLOB,BLOBLEN) of PUBKEY_TYPE into the cache. */
void
be_cache_pubkey (ctrl_t ctrl, const unsigned char *ubid,
const void *blob, unsigned int bloblen,
enum pubkey_types pubkey_type)
{
gpg_error_t err;
(void)ctrl;
if (pubkey_type == PUBKEY_TYPE_OPGP)
{
struct _keybox_openpgp_info info;
struct _keybox_openpgp_key_info *kinfo;
err = _keybox_parse_openpgp (blob, bloblen, NULL, &info);
if (err)
{
log_info ("cache: error parsing OpenPGP blob: %s\n",
gpg_strerror (err));
return;
}
blob_table_put (ubid, pubkey_type, blob, bloblen);
kinfo = &info.primary;
key_table_put (kinfo->fpr, kinfo->fprlen, ubid, 0);
if (info.nsubkeys)
for (kinfo = &info.subkeys; kinfo; kinfo = kinfo->next)
key_table_put (kinfo->fpr, kinfo->fprlen, ubid, 1);
_keybox_destroy_openpgp_info (&info);
}
}
/* Put the a non-found mark for PUBKEY_TYPE into the cache. The
* indices are taken from the search descriptors (DESC,NDESC). */
void
be_cache_not_found (ctrl_t ctrl, enum pubkey_types pubkey_type,
KEYDB_SEARCH_DESC *desc, unsigned int ndesc)
{
unsigned int n;
(void)ctrl;
(void)pubkey_type;
for (n=0; n < ndesc; n++)
{
switch (desc->mode)
{
case KEYDB_SEARCH_MODE_LONG_KID:
key_table_put_no_kid (desc[n].u.kid[0], desc[n].u.kid[1]);
break;
case KEYDB_SEARCH_MODE_FPR:
key_table_put_no_fpr (desc[n].u.fpr, desc[n].fprlen);
break;
default:
break;
}
}
}
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