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			117 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
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			117 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
| =pod
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| 
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| =head1 NAME
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| 
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| SSL_want, SSL_want_nothing, SSL_want_read, SSL_want_write, SSL_want_x509_lookup,
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| SSL_want_async, SSL_want_async_job, SSL_want_client_hello_cb - obtain state
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| information TLS/SSL I/O operation
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| 
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| =head1 SYNOPSIS
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| 
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|  #include <openssl/ssl.h>
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| 
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|  int SSL_want(const SSL *ssl);
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|  int SSL_want_nothing(const SSL *ssl);
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|  int SSL_want_read(const SSL *ssl);
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|  int SSL_want_write(const SSL *ssl);
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|  int SSL_want_x509_lookup(const SSL *ssl);
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|  int SSL_want_async(const SSL *ssl);
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|  int SSL_want_async_job(const SSL *ssl);
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|  int SSL_want_client_hello_cb(const SSL *ssl);
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| 
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| =head1 DESCRIPTION
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| 
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| SSL_want() returns state information for the SSL object B<ssl>.
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| 
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| The other SSL_want_*() calls are shortcuts for the possible states returned
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| by SSL_want().
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| 
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| =head1 NOTES
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| 
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| SSL_want() examines the internal state information of the SSL object. Its
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| return values are similar to that of L<SSL_get_error(3)>.
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| Unlike L<SSL_get_error(3)>, which also evaluates the
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| error queue, the results are obtained by examining an internal state flag
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| only. The information must therefore only be used for normal operation under
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| non-blocking I/O. Error conditions are not handled and must be treated
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| using L<SSL_get_error(3)>.
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| 
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| The result returned by SSL_want() should always be consistent with
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| the result of L<SSL_get_error(3)>.
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| 
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| =head1 RETURN VALUES
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| 
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| The following return values can currently occur for SSL_want():
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| 
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| =over 4
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| 
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| =item SSL_NOTHING
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| 
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| There is no data to be written or to be read.
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| 
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| =item SSL_WRITING
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| 
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| There are data in the SSL buffer that must be written to the underlying
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| B<BIO> layer in order to complete the actual SSL_*() operation.
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| A call to L<SSL_get_error(3)> should return
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| SSL_ERROR_WANT_WRITE.
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| 
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| =item SSL_READING
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| 
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| More data must be read from the underlying B<BIO> layer in order to
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| complete the actual SSL_*() operation.
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| A call to L<SSL_get_error(3)> should return
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| SSL_ERROR_WANT_READ.
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| 
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| =item SSL_X509_LOOKUP
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| 
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| The operation did not complete because an application callback set by
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| SSL_CTX_set_client_cert_cb() has asked to be called again.
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| A call to L<SSL_get_error(3)> should return
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| SSL_ERROR_WANT_X509_LOOKUP.
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| 
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| =item SSL_ASYNC_PAUSED
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| 
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| An asynchronous operation partially completed and was then paused. See
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| L<SSL_get_all_async_fds(3)>. A call to L<SSL_get_error(3)> should return
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| SSL_ERROR_WANT_ASYNC.
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| 
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| =item SSL_ASYNC_NO_JOBS
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| 
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| The asynchronous job could not be started because there were no async jobs
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| available in the pool (see ASYNC_init_thread(3)). A call to L<SSL_get_error(3)>
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| should return SSL_ERROR_WANT_ASYNC_JOB.
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| 
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| =item SSL_CLIENT_HELLO_CB
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| 
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| The operation did not complete because an application callback set by
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| SSL_CTX_set_client_hello_cb() has asked to be called again.
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| A call to L<SSL_get_error(3)> should return
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| SSL_ERROR_WANT_CLIENT_HELLO_CB.
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| 
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| =back
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| 
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| SSL_want_nothing(), SSL_want_read(), SSL_want_write(), SSL_want_x509_lookup(),
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| SSL_want_async(), SSL_want_async_job(), and SSL_want_client_hello_cb() return
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| 1, when the corresponding condition is true or 0 otherwise.
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| 
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| =head1 SEE ALSO
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| 
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| L<ssl(7)>, L<SSL_get_error(3)>
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| 
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| =head1 HISTORY
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| 
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| The SSL_want_client_hello_cb() function and the SSL_CLIENT_HELLO_CB return value
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| were added in OpenSSL 1.1.1.
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| 
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| =head1 COPYRIGHT
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| 
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| Copyright 2001-2017 The OpenSSL Project Authors. All Rights Reserved.
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| 
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| Licensed under the Apache License 2.0 (the "License").  You may not use
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| this file except in compliance with the License.  You can obtain a copy
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| in the file LICENSE in the source distribution or at
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| L<https://www.openssl.org/source/license.html>.
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| 
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| =cut
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