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_int.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     ossl_ctx_thread_stop(ctx);
  84
  85     onfree = ctx->onfreelist;
  86     while (onfree != NULL) {
  87         onfree->fn(ctx);
  88         tmp = onfree;
  89         onfree = onfree->next;
  90         OPENSSL_free(tmp);
  91     }
  92     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_OPENSSL_CTX, NULL, &ctx->data);
  93     crypto_cleanup_all_ex_data_int(ctx);
  94     CRYPTO_THREAD_lock_free(ctx->oncelock);
  95     CRYPTO_THREAD_lock_free(ctx->lock);
  96     ctx->lock = NULL;
  97     return 1;
  98 }
  99
 100 #ifndef FIPS_MODE
 101 void openssl_ctx_default_deinit(void)
 102 {
 103     context_deinit(default_context);
 104 }
 105
 106 static CRYPTO_ONCE default_context_init = CRYPTO_ONCE_STATIC_INIT;
 107 DEFINE_RUN_ONCE_STATIC(do_default_context_init)
 108 {
 109     if (context_init(&default_context_int))
 110         default_context = &default_context_int;
 111
 112     return 1;
 113 }
 114 #endif
 115
 116 OPENSSL_CTX *OPENSSL_CTX_new(void)
 117 {
 118     OPENSSL_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
 119
 120     if (ctx != NULL && !context_init(ctx)) {
 121         OPENSSL_CTX_free(ctx);
 122         ctx = NULL;
 123     }
 124     return ctx;
 125 }
 126
 127 void OPENSSL_CTX_free(OPENSSL_CTX *ctx)
 128 {
 129     if (ctx != NULL)
 130         context_deinit(ctx);
 131     OPENSSL_free(ctx);
 132 }
 133
 134 OPENSSL_CTX *openssl_ctx_get_concrete(OPENSSL_CTX *ctx)
 135 {
 136 #ifndef FIPS_MODE
 137     if (ctx == NULL) {
 138         if (!RUN_ONCE(&default_context_init, do_default_context_init))
 139             return 0;
 140         return default_context;
 141     }
 142 #endif
 143     return ctx;
 144 }
 145
 146 static void openssl_ctx_generic_new(void *parent_ign, void *ptr_ign,
 147                                     CRYPTO_EX_DATA *ad, int index,
 148                                     long argl_ign, void *argp)
 149 {
 150     const OPENSSL_CTX_METHOD *meth = argp;
 151     void *ptr = meth->new_func(crypto_ex_data_get_openssl_ctx(ad));
 152
 153     if (ptr != NULL)
 154         CRYPTO_set_ex_data(ad, index, ptr);
 155 }
 156 static void openssl_ctx_generic_free(void *parent_ign, void *ptr,
 157                                      CRYPTO_EX_DATA *ad, int index,
 158                                      long argl_ign, void *argp)
 159 {
 160     const OPENSSL_CTX_METHOD *meth = argp;
 161
 162     meth->free_func(ptr);
 163 }
 164
 165 /* Non-static so we can use it in context_internal_test */
 166 static int openssl_ctx_init_index(OPENSSL_CTX *ctx, int static_index,
 167                                   const OPENSSL_CTX_METHOD *meth)
 168 {
 169     int idx;
 170
 171     ctx = openssl_ctx_get_concrete(ctx);
 172     if (ctx == NULL)
 173         return 0;
 174
 175     idx = crypto_get_ex_new_index_ex(ctx, CRYPTO_EX_INDEX_OPENSSL_CTX, 0,
 176                                      (void *)meth,
 177                                      openssl_ctx_generic_new,
 178                                      NULL, openssl_ctx_generic_free);
 179     if (idx < 0)
 180         return 0;
 181
 182     ctx->dyn_indexes[static_index] = idx;
 183     return 1;
 184 }
 185
 186 void *openssl_ctx_get_data(OPENSSL_CTX *ctx, int index,
 187                            const OPENSSL_CTX_METHOD *meth)
 188 {
 189     void *data = NULL;
 190
 191     ctx = openssl_ctx_get_concrete(ctx);
 192     if (ctx == NULL)
 193         return NULL;
 194
 195     CRYPTO_THREAD_read_lock(ctx->lock);
 196
 197     if (ctx->dyn_indexes[index] == -1
 198             && !openssl_ctx_init_index(ctx, index, meth)) {
 199         CRYPTO_THREAD_unlock(ctx->lock);
 200         return NULL;
 201     }
 202
 203     /* The alloc call ensures there's a value there */
 204     if (CRYPTO_alloc_ex_data(CRYPTO_EX_INDEX_OPENSSL_CTX, NULL,
 205                              &ctx->data, ctx->dyn_indexes[index]))
 206         data = CRYPTO_get_ex_data(&ctx->data, ctx->dyn_indexes[index]);
 207
 208     CRYPTO_THREAD_unlock(ctx->lock);
 209
 210     return data;
 211 }
 212
 213 OSSL_EX_DATA_GLOBAL *openssl_ctx_get_ex_data_global(OPENSSL_CTX *ctx)
 214 {
 215     ctx = openssl_ctx_get_concrete(ctx);
 216     if (ctx == NULL)
 217         return NULL;
 218     return &ctx->global;
 219 }
 220
 221 int openssl_ctx_run_once(OPENSSL_CTX *ctx, unsigned int idx,
 222                          openssl_ctx_run_once_fn run_once_fn)
 223 {
 224     int done = 0, ret = 0;
 225
 226     ctx = openssl_ctx_get_concrete(ctx);
 227     if (ctx == NULL)
 228         return 0;
 229
 230     CRYPTO_THREAD_read_lock(ctx->oncelock);
 231     done = ctx->run_once_done[idx];
 232     if (done)
 233         ret = ctx->run_once_ret[idx];
 234     CRYPTO_THREAD_unlock(ctx->oncelock);
 235
 236     if (done)
 237         return ret;
 238
 239     CRYPTO_THREAD_write_lock(ctx->oncelock);
 240     if (ctx->run_once_done[idx]) {
 241         ret = ctx->run_once_ret[idx];
 242         CRYPTO_THREAD_unlock(ctx->oncelock);
 243         return ret;
 244     }
 245
 246     ret = run_once_fn(ctx);
 247     ctx->run_once_done[idx] = 1;
 248     ctx->run_once_ret[idx] = ret;
 249     CRYPTO_THREAD_unlock(ctx->oncelock);
 250
 251     return ret;
 252 }
 253
 254 int openssl_ctx_onfree(OPENSSL_CTX *ctx, openssl_ctx_onfree_fn onfreefn)
 255 {
 256     struct openssl_ctx_onfree_list_st *newonfree
 257         = OPENSSL_malloc(sizeof(*newonfree));
 258
 259     if (newonfree == NULL)
 260         return 0;
 261
 262     newonfree->fn = onfreefn;
 263     newonfree->next = ctx->onfreelist;
 264     ctx->onfreelist = newonfree;
 265
 266     return 1;
 267 }