xref: /freebsd/crypto/openssl/crypto/property/defn_cache.c (revision f25b8c9fb4f58cf61adb47d7570abe7caa6d385d)
1 /*
2  * Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.
3  * Copyright (c) 2019, Oracle and/or its affiliates.  All rights reserved.
4  *
5  * Licensed under the Apache License 2.0 (the "License").  You may not use
6  * this file except in compliance with the License.  You can obtain a copy
7  * in the file LICENSE in the source distribution or at
8  * https://www.openssl.org/source/license.html
9  */
10 
11 #include <string.h>
12 #include <openssl/err.h>
13 #include <openssl/lhash.h>
14 #include "internal/propertyerr.h"
15 #include "internal/property.h"
16 #include "internal/core.h"
17 #include "property_local.h"
18 #include "crypto/context.h"
19 
20 /*
21  * Implement a property definition cache.
22  * These functions assume that they are called under a write lock.
23  * No attempt is made to clean out the cache, except when it is shut down.
24  */
25 
26 typedef struct {
27     const char *prop;
28     OSSL_PROPERTY_LIST *defn;
29     char body[1];
30 } PROPERTY_DEFN_ELEM;
31 
32 DEFINE_LHASH_OF_EX(PROPERTY_DEFN_ELEM);
33 
property_defn_hash(const PROPERTY_DEFN_ELEM * a)34 static unsigned long property_defn_hash(const PROPERTY_DEFN_ELEM *a)
35 {
36     return OPENSSL_LH_strhash(a->prop);
37 }
38 
property_defn_cmp(const PROPERTY_DEFN_ELEM * a,const PROPERTY_DEFN_ELEM * b)39 static int property_defn_cmp(const PROPERTY_DEFN_ELEM *a,
40     const PROPERTY_DEFN_ELEM *b)
41 {
42     return strcmp(a->prop, b->prop);
43 }
44 
property_defn_free(PROPERTY_DEFN_ELEM * elem)45 static void property_defn_free(PROPERTY_DEFN_ELEM *elem)
46 {
47     ossl_property_free(elem->defn);
48     OPENSSL_free(elem);
49 }
50 
ossl_property_defns_free(void * vproperty_defns)51 void ossl_property_defns_free(void *vproperty_defns)
52 {
53     LHASH_OF(PROPERTY_DEFN_ELEM) *property_defns = vproperty_defns;
54 
55     if (property_defns != NULL) {
56         lh_PROPERTY_DEFN_ELEM_doall(property_defns,
57             &property_defn_free);
58         lh_PROPERTY_DEFN_ELEM_free(property_defns);
59     }
60 }
61 
ossl_property_defns_new(OSSL_LIB_CTX * ctx)62 void *ossl_property_defns_new(OSSL_LIB_CTX *ctx)
63 {
64     return lh_PROPERTY_DEFN_ELEM_new(&property_defn_hash, &property_defn_cmp);
65 }
66 
ossl_prop_defn_get(OSSL_LIB_CTX * ctx,const char * prop)67 OSSL_PROPERTY_LIST *ossl_prop_defn_get(OSSL_LIB_CTX *ctx, const char *prop)
68 {
69     PROPERTY_DEFN_ELEM elem, *r;
70     LHASH_OF(PROPERTY_DEFN_ELEM) *property_defns;
71 
72     property_defns = ossl_lib_ctx_get_data(ctx,
73         OSSL_LIB_CTX_PROPERTY_DEFN_INDEX);
74     if (!ossl_assert(property_defns != NULL) || !ossl_lib_ctx_read_lock(ctx))
75         return NULL;
76 
77     elem.prop = prop;
78     r = lh_PROPERTY_DEFN_ELEM_retrieve(property_defns, &elem);
79     ossl_lib_ctx_unlock(ctx);
80     if (r == NULL || !ossl_assert(r->defn != NULL))
81         return NULL;
82     return r->defn;
83 }
84 
85 /*
86  * Cache the property list for a given property string *pl.
87  * If an entry already exists in the cache *pl is freed and
88  * overwritten with the existing entry from the cache.
89  */
ossl_prop_defn_set(OSSL_LIB_CTX * ctx,const char * prop,OSSL_PROPERTY_LIST ** pl)90 int ossl_prop_defn_set(OSSL_LIB_CTX *ctx, const char *prop,
91     OSSL_PROPERTY_LIST **pl)
92 {
93     PROPERTY_DEFN_ELEM elem, *old, *p = NULL;
94     size_t len;
95     LHASH_OF(PROPERTY_DEFN_ELEM) *property_defns;
96     int res = 1;
97 
98     property_defns = ossl_lib_ctx_get_data(ctx,
99         OSSL_LIB_CTX_PROPERTY_DEFN_INDEX);
100     if (property_defns == NULL)
101         return 0;
102 
103     if (prop == NULL)
104         return 1;
105 
106     if (!ossl_lib_ctx_write_lock(ctx))
107         return 0;
108     elem.prop = prop;
109     if (pl == NULL) {
110         lh_PROPERTY_DEFN_ELEM_delete(property_defns, &elem);
111         goto end;
112     }
113     /* check if property definition is in the cache already */
114     if ((p = lh_PROPERTY_DEFN_ELEM_retrieve(property_defns, &elem)) != NULL) {
115         ossl_property_free(*pl);
116         *pl = p->defn;
117         goto end;
118     }
119     len = strlen(prop);
120     p = OPENSSL_malloc(sizeof(*p) + len);
121     if (p != NULL) {
122         p->prop = p->body;
123         p->defn = *pl;
124         memcpy(p->body, prop, len + 1);
125         old = lh_PROPERTY_DEFN_ELEM_insert(property_defns, p);
126         if (!ossl_assert(old == NULL))
127             /* This should not happen. An existing entry is handled above. */
128             goto end;
129         if (!lh_PROPERTY_DEFN_ELEM_error(property_defns))
130             goto end;
131     }
132     OPENSSL_free(p);
133     res = 0;
134 end:
135     ossl_lib_ctx_unlock(ctx);
136     return res;
137 }
138