1SSL_want(3) OpenSSL SSL_want(3)
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6 SSL_want, SSL_want_nothing, SSL_want_read, SSL_want_write,
7 SSL_want_x509_lookup - obtain state information TLS/SSL I/O operation
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10 #include <openssl/ssl.h>
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12 int SSL_want(const SSL *ssl);
13 int SSL_want_nothing(const SSL *ssl);
14 int SSL_want_read(const SSL *ssl);
15 int SSL_want_write(const SSL *ssl);
16 int SSL_want_x509_lookup(const SSL *ssl);
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19 SSL_want() returns state information for the SSL object ssl.
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21 The other SSL_want_*() calls are shortcuts for the possible states
22 returned by SSL_want().
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25 SSL_want() examines the internal state information of the SSL object.
26 Its return values are similar to that of SSL_get_error(3). Unlike
27 SSL_get_error(3), which also evaluates the error queue, the results are
28 obtained by examining an internal state flag only. The information must
29 therefore only be used for normal operation under non-blocking I/O.
30 Error conditions are not handled and must be treated using
31 SSL_get_error(3).
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33 The result returned by SSL_want() should always be consistent with the
34 result of SSL_get_error(3).
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37 The following return values can currently occur for SSL_want():
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39 SSL_NOTHING
40 There is no data to be written or to be read.
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42 SSL_WRITING
43 There are data in the SSL buffer that must be written to the
44 underlying BIO layer in order to complete the actual SSL_*()
45 operation. A call to SSL_get_error(3) should return
46 SSL_ERROR_WANT_WRITE.
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48 SSL_READING
49 More data must be read from the underlying BIO layer in order to
50 complete the actual SSL_*() operation. A call to SSL_get_error(3)
51 should return SSL_ERROR_WANT_READ.
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53 SSL_X509_LOOKUP
54 The operation did not complete because an application callback set
55 by SSL_CTX_set_client_cert_cb() has asked to be called again. A
56 call to SSL_get_error(3) should return SSL_ERROR_WANT_X509_LOOKUP.
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58 SSL_want_nothing(), SSL_want_read(), SSL_want_write(),
59 SSL_want_x509_lookup() return 1, when the corresponding condition is
60 true or 0 otherwise.
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63 ssl(3), err(3), SSL_get_error(3)
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671.0.2o 2019-09-10 SSL_want(3)