crypto/context.c

   1 /*
   2  * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include "internal/cryptlib.h"
  11 #include "internal/thread_once.h"
  12
  13 struct openssl_ctx_onfree_list_st {
  14     openssl_ctx_onfree_fn *fn;
  15     struct openssl_ctx_onfree_list_st *next;
  16 };
  17
  18 struct openssl_ctx_st {
  19     CRYPTO_RWLOCK *lock;
  20     CRYPTO_EX_DATA data;
  21
  22     /*
  23      * For most data in the OPENSSL_CTX we just use ex_data to store it. But
  24      * that doesn't work for ex_data itself - so we store that directly.
  25      */
  26     OSSL_EX_DATA_GLOBAL global;
  27
  28     /* Map internal static indexes to dynamically created indexes */
  29     int dyn_indexes[OPENSSL_CTX_MAX_INDEXES];
  30
  31     CRYPTO_RWLOCK *oncelock;
  32     int run_once_done[OPENSSL_CTX_MAX_RUN_ONCE];
  33     int run_once_ret[OPENSSL_CTX_MAX_RUN_ONCE];
  34     struct openssl_ctx_onfree_list_st *onfreelist;
  35 };
  36
  37 #ifndef FIPS_MODE
  38 static OPENSSL_CTX default_context_int;
  39
  40 /* Always points at default_context_int if it has been initialised */
  41 static OPENSSL_CTX *default_context = NULL;
  42 #endif
  43
  44 static int context_init(OPENSSL_CTX *ctx)
  45 {
  46     size_t i;
  47
  48     ctx->lock = CRYPTO_THREAD_lock_new();
  49     if (ctx->lock == NULL)
  50         return 0;
  51
  52     ctx->oncelock = CRYPTO_THREAD_lock_new();
  53     if (ctx->oncelock == NULL)
  54         goto err;
  55
  56     for (i = 0; i < OPENSSL_CTX_MAX_INDEXES; i++)
  57         ctx->dyn_indexes[i] = -1;
  58
  59     if (!do_ex_data_init(ctx))
  60         goto err;
  61
  62     if (!crypto_new_ex_data_ex(ctx, CRYPTO_EX_INDEX_OPENSSL_CTX, NULL,
  63                                &ctx->data)) {
  64         crypto_cleanup_all_ex_data_int(ctx);
  65         goto err;
  66     }
  67
  68     return 1;
  69  err:
  70     CRYPTO_THREAD_lock_free(ctx->oncelock);
  71     CRYPTO_THREAD_lock_free(ctx->lock);
  72     ctx->lock = NULL;
  73     return 0;
  74 }
  75
  76 static int context_deinit(OPENSSL_CTX *ctx)
  77 {
  78     struct openssl_ctx_onfree_list_st *tmp, *onfree;
  79
  80     if (ctx == NULL)
  81         return 1;
  82
  83     onfree = ctx->onfreelist;
  84     while (onfree != NULL) {
  85         onfree->fn(ctx);
  86         tmp = onfree;
  87         onfree = onfree->next;
  88         OPENSSL_free(tmp);
  89     }
  90     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_OPENSSL_CTX, NULL, &ctx->data);
  91     crypto_cleanup_all_ex_data_int(ctx);
  92     CRYPTO_THREAD_lock_free(ctx->oncelock);
  93     CRYPTO_THREAD_lock_free(ctx->lock);
  94     ctx->lock = NULL;
  95     return 1;
  96 }
  97
  98 #ifndef FIPS_MODE
  99 void openssl_ctx_default_deinit(void)
 100 {
 101     context_deinit(default_context);
 102 }
 103
 104 static CRYPTO_ONCE default_context_init = CRYPTO_ONCE_STATIC_INIT;
 105 DEFINE_RUN_ONCE_STATIC(do_default_context_init)
 106 {
 107     if (context_init(&default_context_int))
 108         default_context = &default_context_int;
 109
 110     return 1;
 111 }
 112 #endif
 113
 114 OPENSSL_CTX *OPENSSL_CTX_new(void)
 115 {
 116     OPENSSL_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
 117
 118     if (ctx != NULL && !context_init(ctx)) {
 119         OPENSSL_CTX_free(ctx);
 120         ctx = NULL;
 121     }
 122     return ctx;
 123 }
 124
 125 void OPENSSL_CTX_free(OPENSSL_CTX *ctx)
 126 {
 127     if (ctx != NULL)
 128         context_deinit(ctx);
 129     OPENSSL_free(ctx);
 130 }
 131
 132 static void openssl_ctx_generic_new(void *parent_ign, void *ptr_ign,
 133                                     CRYPTO_EX_DATA *ad, int index,
 134                                     long argl_ign, void *argp)
 135 {
 136     const OPENSSL_CTX_METHOD *meth = argp;
 137     void *ptr = meth->new_func(crypto_ex_data_get_openssl_ctx(ad));
 138
 139     if (ptr != NULL)
 140         CRYPTO_set_ex_data(ad, index, ptr);
 141 }
 142 static void openssl_ctx_generic_free(void *parent_ign, void *ptr,
 143                                      CRYPTO_EX_DATA *ad, int index,
 144                                      long argl_ign, void *argp)
 145 {
 146     const OPENSSL_CTX_METHOD *meth = argp;
 147
 148     meth->free_func(ptr);
 149 }
 150
 151 /* Non-static so we can use it in context_internal_test */
 152 static int openssl_ctx_init_index(OPENSSL_CTX *ctx, int static_index,
 153                                   const OPENSSL_CTX_METHOD *meth)
 154 {
 155     int idx;
 156
 157 #ifndef FIPS_MODE
 158     if (ctx == NULL) {
 159         if (!RUN_ONCE(&default_context_init, do_default_context_init))
 160             return 0;
 161         ctx = default_context;
 162     }
 163 #endif
 164     if (ctx == NULL)
 165         return 0;
 166
 167     idx = crypto_get_ex_new_index_ex(ctx, CRYPTO_EX_INDEX_OPENSSL_CTX, 0,
 168                                      (void *)meth,
 169                                      openssl_ctx_generic_new,
 170                                      NULL, openssl_ctx_generic_free);
 171     if (idx < 0)
 172         return 0;
 173
 174     ctx->dyn_indexes[static_index] = idx;
 175     return 1;
 176 }
 177
 178 void *openssl_ctx_get_data(OPENSSL_CTX *ctx, int index,
 179                            const OPENSSL_CTX_METHOD *meth)
 180 {
 181     void *data = NULL;
 182
 183 #ifndef FIPS_MODE
 184     if (ctx == NULL) {
 185         if (!RUN_ONCE(&default_context_init, do_default_context_init))
 186             return NULL;
 187         ctx = default_context;
 188     }
 189 #endif
 190     if (ctx == NULL)
 191         return NULL;
 192
 193     CRYPTO_THREAD_read_lock(ctx->lock);
 194
 195     if (ctx->dyn_indexes[index] == -1
 196             && !openssl_ctx_init_index(ctx, index, meth)) {
 197         CRYPTO_THREAD_unlock(ctx->lock);
 198         return NULL;
 199     }
 200
 201     /* The alloc call ensures there's a value there */
 202     if (CRYPTO_alloc_ex_data(CRYPTO_EX_INDEX_OPENSSL_CTX, NULL,
 203                              &ctx->data, ctx->dyn_indexes[index]))
 204         data = CRYPTO_get_ex_data(&ctx->data, ctx->dyn_indexes[index]);
 205
 206     CRYPTO_THREAD_unlock(ctx->lock);
 207
 208     return data;
 209 }
 210
 211 OSSL_EX_DATA_GLOBAL *openssl_ctx_get_ex_data_global(OPENSSL_CTX *ctx)
 212 {
 213     /*
 214      * The default context code is not needed in FIPS_MODE and ctx should never
 215      * be NULL in the FIPS provider. However we compile this code out to ensure
 216      * we fail immediately if ctx == NULL in FIPS_MODE
 217      */
 218 #ifndef FIPS_MODE
 219     if (ctx == NULL) {
 220         if (!RUN_ONCE(&default_context_init, do_default_context_init))
 221             return NULL;
 222         ctx = default_context;
 223     }
 224 #endif
 225     if (ctx == NULL)
 226         return NULL;
 227     return &ctx->global;
 228 }
 229
 230 int openssl_ctx_run_once(OPENSSL_CTX *ctx, unsigned int idx,
 231                          openssl_ctx_run_once_fn run_once_fn)
 232 {
 233     int done = 0, ret = 0;
 234
 235 #ifndef FIPS_MODE
 236     if (ctx == NULL) {
 237         if (!RUN_ONCE(&default_context_init, do_default_context_init))
 238             return 0;
 239         ctx = default_context;
 240     }
 241 #endif
 242     if (ctx == NULL)
 243         return 0;
 244
 245     CRYPTO_THREAD_read_lock(ctx->oncelock);
 246     done = ctx->run_once_done[idx];
 247     if (done)
 248         ret = ctx->run_once_ret[idx];
 249     CRYPTO_THREAD_unlock(ctx->oncelock);
 250
 251     if (done)
 252         return ret;
 253
 254     CRYPTO_THREAD_write_lock(ctx->oncelock);
 255     if (ctx->run_once_done[idx]) {
 256         ret = ctx->run_once_ret[idx];
 257         CRYPTO_THREAD_unlock(ctx->oncelock);
 258         return ret;
 259     }
 260
 261     ret = run_once_fn(ctx);
 262     ctx->run_once_done[idx] = 1;
 263     ctx->run_once_ret[idx] = ret;
 264     CRYPTO_THREAD_unlock(ctx->oncelock);
 265
 266     return ret;
 267 }
 268
 269 int openssl_ctx_onfree(OPENSSL_CTX *ctx, openssl_ctx_onfree_fn onfreefn)
 270 {
 271     struct openssl_ctx_onfree_list_st *newonfree
 272         = OPENSSL_malloc(sizeof(*newonfree));
 273
 274     if (newonfree == NULL)
 275         return 0;
 276
 277     newonfree->fn = onfreefn;
 278     newonfree->next = ctx->onfreelist;
 279     ctx->onfreelist = newonfree;
 280
 281     return 1;
 282 }