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 OPENSSL_CTX *openssl_ctx_get_concrete(OPENSSL_CTX *ctx)
 133 {
 134 #ifndef FIPS_MODE
 135     if (ctx == NULL) {
 136         if (!RUN_ONCE(&default_context_init, do_default_context_init))
 137             return 0;
 138         return default_context;
 139     }
 140 #endif
 141     return ctx;
 142 }
 143
 144 static void openssl_ctx_generic_new(void *parent_ign, void *ptr_ign,
 145                                     CRYPTO_EX_DATA *ad, int index,
 146                                     long argl_ign, void *argp)
 147 {
 148     const OPENSSL_CTX_METHOD *meth = argp;
 149     void *ptr = meth->new_func(crypto_ex_data_get_openssl_ctx(ad));
 150
 151     if (ptr != NULL)
 152         CRYPTO_set_ex_data(ad, index, ptr);
 153 }
 154 static void openssl_ctx_generic_free(void *parent_ign, void *ptr,
 155                                      CRYPTO_EX_DATA *ad, int index,
 156                                      long argl_ign, void *argp)
 157 {
 158     const OPENSSL_CTX_METHOD *meth = argp;
 159
 160     meth->free_func(ptr);
 161 }
 162
 163 /* Non-static so we can use it in context_internal_test */
 164 static int openssl_ctx_init_index(OPENSSL_CTX *ctx, int static_index,
 165                                   const OPENSSL_CTX_METHOD *meth)
 166 {
 167     int idx;
 168
 169     ctx = openssl_ctx_get_concrete(ctx);
 170     if (ctx == NULL)
 171         return 0;
 172
 173     idx = crypto_get_ex_new_index_ex(ctx, CRYPTO_EX_INDEX_OPENSSL_CTX, 0,
 174                                      (void *)meth,
 175                                      openssl_ctx_generic_new,
 176                                      NULL, openssl_ctx_generic_free);
 177     if (idx < 0)
 178         return 0;
 179
 180     ctx->dyn_indexes[static_index] = idx;
 181     return 1;
 182 }
 183
 184 void *openssl_ctx_get_data(OPENSSL_CTX *ctx, int index,
 185                            const OPENSSL_CTX_METHOD *meth)
 186 {
 187     void *data = NULL;
 188
 189     ctx = openssl_ctx_get_concrete(ctx);
 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     ctx = openssl_ctx_get_concrete(ctx);
 214     if (ctx == NULL)
 215         return NULL;
 216     return &ctx->global;
 217 }
 218
 219 int openssl_ctx_run_once(OPENSSL_CTX *ctx, unsigned int idx,
 220                          openssl_ctx_run_once_fn run_once_fn)
 221 {
 222     int done = 0, ret = 0;
 223
 224     ctx = openssl_ctx_get_concrete(ctx);
 225     if (ctx == NULL)
 226         return 0;
 227
 228     CRYPTO_THREAD_read_lock(ctx->oncelock);
 229     done = ctx->run_once_done[idx];
 230     if (done)
 231         ret = ctx->run_once_ret[idx];
 232     CRYPTO_THREAD_unlock(ctx->oncelock);
 233
 234     if (done)
 235         return ret;
 236
 237     CRYPTO_THREAD_write_lock(ctx->oncelock);
 238     if (ctx->run_once_done[idx]) {
 239         ret = ctx->run_once_ret[idx];
 240         CRYPTO_THREAD_unlock(ctx->oncelock);
 241         return ret;
 242     }
 243
 244     ret = run_once_fn(ctx);
 245     ctx->run_once_done[idx] = 1;
 246     ctx->run_once_ret[idx] = ret;
 247     CRYPTO_THREAD_unlock(ctx->oncelock);
 248
 249     return ret;
 250 }
 251
 252 int openssl_ctx_onfree(OPENSSL_CTX *ctx, openssl_ctx_onfree_fn onfreefn)
 253 {
 254     struct openssl_ctx_onfree_list_st *newonfree
 255         = OPENSSL_malloc(sizeof(*newonfree));
 256
 257     if (newonfree == NULL)
 258         return 0;
 259
 260     newonfree->fn = onfreefn;
 261     newonfree->next = ctx->onfreelist;
 262     ctx->onfreelist = newonfree;
 263
 264     return 1;
 265 }