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_st {
  14     CRYPTO_RWLOCK *lock;
  15     CRYPTO_EX_DATA data;
  16 };
  17
  18 static OPENSSL_CTX default_context;
  19
  20 static int context_init(OPENSSL_CTX *ctx)
  21 {
  22     return (ctx->lock = CRYPTO_THREAD_lock_new()) != NULL
  23         && CRYPTO_new_ex_data(CRYPTO_EX_INDEX_OPENSSL_CTX, NULL,
  24                               &ctx->data);
  25 }
  26
  27 static int context_deinit(OPENSSL_CTX *ctx)
  28 {
  29     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_OPENSSL_CTX, NULL, &ctx->data);
  30     CRYPTO_THREAD_lock_free(ctx->lock);
  31     return 1;
  32 }
  33
  34 static CRYPTO_ONCE default_context_init = CRYPTO_ONCE_STATIC_INIT;
  35 static void do_default_context_deinit(void)
  36 {
  37     context_deinit(&default_context);
  38 }
  39 DEFINE_RUN_ONCE_STATIC(do_default_context_init)
  40 {
  41     return OPENSSL_init_crypto(0, NULL)
  42         && context_init(&default_context)
  43         && OPENSSL_atexit(do_default_context_deinit);
  44 }
  45
  46 OPENSSL_CTX *OPENSSL_CTX_new(void)
  47 {
  48     OPENSSL_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
  49
  50     if (ctx != NULL && !context_init(ctx)) {
  51         OPENSSL_CTX_free(ctx);
  52         ctx = NULL;
  53     }
  54     return ctx;
  55 }
  56
  57 void OPENSSL_CTX_free(OPENSSL_CTX *ctx)
  58 {
  59     if (ctx != NULL)
  60         context_deinit(ctx);
  61     OPENSSL_free(ctx);
  62 }
  63
  64 static void openssl_ctx_generic_new(void *parent_ign, void *ptr_ign,
  65                                     CRYPTO_EX_DATA *ad, int index,
  66                                     long argl_ign, void *argp)
  67 {
  68     const OPENSSL_CTX_METHOD *meth = argp;
  69     void *ptr = meth->new_func();
  70
  71     if (ptr != NULL)
  72         CRYPTO_set_ex_data(ad, index, ptr);
  73 }
  74 static void openssl_ctx_generic_free(void *parent_ign, void *ptr,
  75                                      CRYPTO_EX_DATA *ad, int index,
  76                                      long argl_ign, void *argp)
  77 {
  78     const OPENSSL_CTX_METHOD *meth = argp;
  79
  80     meth->free_func(ptr);
  81 }
  82 int openssl_ctx_new_index(const OPENSSL_CTX_METHOD *meth)
  83 {
  84     return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_OPENSSL_CTX, 0, (void *)meth,
  85                                    openssl_ctx_generic_new, NULL,
  86                                    openssl_ctx_generic_free);
  87 }
  88
  89 void *openssl_ctx_get_data(OPENSSL_CTX *ctx, int index)
  90 {
  91     void *data = NULL;
  92
  93     if (ctx == NULL) {
  94         if (!RUN_ONCE(&default_context_init, do_default_context_init))
  95             return 0;
  96         ctx = &default_context;
  97     }
  98
  99     CRYPTO_THREAD_read_lock(ctx->lock);
 100
 101     /* The alloc call ensures there's a value there */
 102     if (CRYPTO_alloc_ex_data(CRYPTO_EX_INDEX_OPENSSL_CTX, NULL,
 103                              &ctx->data, index))
 104         data = CRYPTO_get_ex_data(&ctx->data, index);
 105
 106     CRYPTO_THREAD_unlock(ctx->lock);
 107
 108     return data;
 109 }
 110