OPENSSL_init_ssl.pod 2.7 KB

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  1. =pod
  2. =head1 NAME
  3. OPENSSL_init_ssl - OpenSSL (libssl and libcrypto) initialisation
  4. =head1 SYNOPSIS
  5. #include <openssl/ssl.h>
  6. int OPENSSL_init_ssl(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings);
  7. =head1 DESCRIPTION
  8. During normal operation OpenSSL (libssl and libcrypto) will allocate various
  9. resources at start up that must, subsequently, be freed on close down of the
  10. library. Additionally some resources are allocated on a per thread basis (if the
  11. application is multi-threaded), and these resources must be freed prior to the
  12. thread closing.
  13. As of version 1.1.0 OpenSSL will automatically allocate all resources that it
  14. needs so no explicit initialisation is required. Similarly it will also
  15. automatically deinitialise as required.
  16. However, there may be situations when explicit initialisation is desirable or
  17. needed, for example when some nondefault initialisation is required. The
  18. function OPENSSL_init_ssl() can be used for this purpose. Calling
  19. this function will explicitly initialise BOTH libcrypto and libssl. To
  20. explicitly initialise ONLY libcrypto see the
  21. L<OPENSSL_init_crypto(3)> function.
  22. Numerous internal OpenSSL functions call OPENSSL_init_ssl().
  23. Therefore, in order to perform nondefault initialisation,
  24. OPENSSL_init_ssl() MUST be called by application code prior to
  25. any other OpenSSL function calls.
  26. The B<opts> parameter specifies which aspects of libssl and libcrypto should be
  27. initialised. Valid options for libcrypto are described on the
  28. L<OPENSSL_init_crypto(3)> page. In addition to any libcrypto
  29. specific option the following libssl options can also be used:
  30. =over 4
  31. =item OPENSSL_INIT_NO_LOAD_SSL_STRINGS
  32. Suppress automatic loading of the libssl error strings. This option is
  33. not a default option. Once selected subsequent calls to
  34. OPENSSL_init_ssl() with the option
  35. B<OPENSSL_INIT_LOAD_SSL_STRINGS> will be ignored.
  36. =item OPENSSL_INIT_LOAD_SSL_STRINGS
  37. Automatic loading of the libssl error strings. This option is a
  38. default option. Once selected subsequent calls to
  39. OPENSSL_init_ssl() with the option
  40. B<OPENSSL_INIT_LOAD_SSL_STRINGS> will be ignored.
  41. =back
  42. OPENSSL_init_ssl() takes a B<settings> parameter which can be used to
  43. set parameter values. See L<OPENSSL_init_crypto(3)> for details.
  44. =head1 RETURN VALUES
  45. The function OPENSSL_init_ssl() returns 1 on success or 0 on error.
  46. =head1 SEE ALSO
  47. L<OPENSSL_init_crypto(3)>
  48. =head1 HISTORY
  49. The OPENSSL_init_ssl() function was added in OpenSSL 1.1.0.
  50. =head1 COPYRIGHT
  51. Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
  52. Licensed under the Apache License 2.0 (the "License"). You may not use
  53. this file except in compliance with the License. You can obtain a copy
  54. in the file LICENSE in the source distribution or at
  55. L<https://www.openssl.org/source/license.html>.
  56. =cut