1SSL_ACCEPT(3) OpenSSL SSL_ACCEPT(3)
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6 SSL_accept - wait for a TLS/SSL client to initiate a TLS/SSL handshake
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9 #include <openssl/ssl.h>
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11 int SSL_accept(SSL *ssl);
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14 SSL_accept() waits for a TLS/SSL client to initiate the TLS/SSL
15 handshake. The communication channel must already have been set and
16 assigned to the ssl by setting an underlying BIO.
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19 The behaviour of SSL_accept() depends on the underlying BIO.
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21 If the underlying BIO is blocking, SSL_accept() will only return once
22 the handshake has been finished or an error occurred.
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24 If the underlying BIO is nonblocking, SSL_accept() will also return
25 when the underlying BIO could not satisfy the needs of SSL_accept() to
26 continue the handshake, indicating the problem by the return value -1.
27 In this case a call to SSL_get_error() with the return value of
28 SSL_accept() will yield SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE.
29 The calling process then must repeat the call after taking appropriate
30 action to satisfy the needs of SSL_accept(). The action depends on the
31 underlying BIO. When using a nonblocking socket, nothing is to be done,
32 but select() can be used to check for the required condition. When
33 using a buffering BIO, like a BIO pair, data must be written into or
34 retrieved out of the BIO before being able to continue.
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37 The following return values can occur:
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39 0 The TLS/SSL handshake was not successful but was shut down
40 controlled and by the specifications of the TLS/SSL protocol. Call
41 SSL_get_error() with the return value ret to find out the reason.
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43 1 The TLS/SSL handshake was successfully completed, a TLS/SSL
44 connection has been established.
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46 <0 The TLS/SSL handshake was not successful because a fatal error
47 occurred either at the protocol level or a connection failure
48 occurred. The shutdown was not clean. It can also occur if action
49 is needed to continue the operation for nonblocking BIOs. Call
50 SSL_get_error() with the return value ret to find out the reason.
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53 SSL_get_error(3), SSL_connect(3), SSL_shutdown(3), ssl(7), bio(7),
54 SSL_set_connect_state(3), SSL_do_handshake(3), SSL_CTX_new(3)
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57 Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
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59 Licensed under the OpenSSL license (the "License"). You may not use
60 this file except in compliance with the License. You can obtain a copy
61 in the file LICENSE in the source distribution or at
62 <https://www.openssl.org/source/license.html>.
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661.1.1k 2021-03-26 SSL_ACCEPT(3)