mirror of
https://github.com/openssl/openssl.git
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74 lines
2.1 KiB
Plaintext
74 lines
2.1 KiB
Plaintext
=pod
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=head1 NAME
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SSL_get_session, SSL_get0_session, SSL_get1_session - retrieve TLS/SSL session data
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=head1 SYNOPSIS
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#include <openssl/ssl.h>
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SSL_SESSION *SSL_get_session(const SSL *ssl);
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SSL_SESSION *SSL_get0_session(const SSL *ssl);
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SSL_SESSION *SSL_get1_session(SSL *ssl);
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=head1 DESCRIPTION
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SSL_get_session() returns a pointer to the B<SSL_SESSION> actually used in
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B<ssl>. The reference count of the B<SSL_SESSION> is not incremented, so
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that the pointer can become invalid by other operations.
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SSL_get0_session() is the same as SSL_get_session().
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SSL_get1_session() is the same as SSL_get_session(), but the reference
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count of the B<SSL_SESSION> is incremented by one.
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=head1 NOTES
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The ssl session contains all information required to re-establish the
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connection without a new handshake.
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SSL_get0_session() returns a pointer to the actual session. As the
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reference counter is not incremented, the pointer is only valid while
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the connection is in use. If L<SSL_clear(3)> or
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L<SSL_free(3)> is called, the session may be removed completely
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(if considered bad), and the pointer obtained will become invalid. Even
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if the session is valid, it can be removed at any time due to timeout
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during L<SSL_CTX_flush_sessions(3)>.
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If the data is to be kept, SSL_get1_session() will increment the reference
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count, so that the session will not be implicitly removed by other operations
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but stays in memory. In order to remove the session
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L<SSL_SESSION_free(3)> must be explicitly called once
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to decrement the reference count again.
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SSL_SESSION objects keep internal link information about the session cache
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list, when being inserted into one SSL_CTX object's session cache.
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One SSL_SESSION object, regardless of its reference count, must therefore
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only be used with one SSL_CTX object (and the SSL objects created
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from this SSL_CTX object).
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=head1 RETURN VALUES
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The following return values can occur:
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=over 4
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=item NULL
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There is no session available in B<ssl>.
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=item Pointer to an SSL_SESSION
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The return value points to the data of an SSL session.
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=back
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=head1 SEE ALSO
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L<ssl(3)>, L<SSL_free(3)>,
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L<SSL_clear(3)>,
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L<SSL_SESSION_free(3)>
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=cut
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