1: =pod
    2: 
    3: =head1 NAME
    4: 
    5: SSL_get_ex_data_X509_STORE_CTX_idx - get ex_data index to access SSL structure
    6: from X509_STORE_CTX
    7: 
    8: =head1 SYNOPSIS
    9: 
   10:  #include <openssl/ssl.h>
   11: 
   12:  int SSL_get_ex_data_X509_STORE_CTX_idx(void);
   13: 
   14: =head1 DESCRIPTION
   15: 
   16: SSL_get_ex_data_X509_STORE_CTX_idx() returns the index number under which
   17: the pointer to the SSL object is stored into the X509_STORE_CTX object.
   18: 
   19: =head1 NOTES
   20: 
   21: Whenever a X509_STORE_CTX object is created for the verification of the
   22: peers certificate during a handshake, a pointer to the SSL object is
   23: stored into the X509_STORE_CTX object to identify the connection affected.
   24: To retrieve this pointer the X509_STORE_CTX_get_ex_data() function can
   25: be used with the correct index. This index is globally the same for all
   26: X509_STORE_CTX objects and can be retrieved using
   27: SSL_get_ex_data_X509_STORE_CTX_idx(). The index value is set when
   28: SSL_get_ex_data_X509_STORE_CTX_idx() is first called either by the application
   29: program directly or indirectly during other SSL setup functions or during
   30: the handshake.
   31: 
   32: The value depends on other index values defined for X509_STORE_CTX objects
   33: before the SSL index is created.
   34: 
   35: =head1 RETURN VALUES
   36: 
   37: =over 4
   38: 
   39: =item E<gt>=0
   40: 
   41: The index value to access the pointer.
   42: 
   43: =item E<lt>0
   44: 
   45: An error occurred, check the error stack for a detailed error message.
   46: 
   47: =back
   48: 
   49: =head1 EXAMPLES
   50: 
   51: The index returned from SSL_get_ex_data_X509_STORE_CTX_idx() allows to
   52: access the SSL object for the connection to be accessed during the
   53: verify_callback() when checking the peers certificate. Please check
   54: the example in L<SSL_CTX_set_verify(3)|SSL_CTX_set_verify(3)>,
   55: 
   56: =head1 SEE ALSO
   57: 
   58: L<ssl(3)|ssl(3)>, L<SSL_CTX_set_verify(3)|SSL_CTX_set_verify(3)>,
   59: L<CRYPTO_set_ex_data(3)|CRYPTO_set_ex_data(3)>
   60: 
   61: =cut