xref: /minix3/crypto/external/bsd/openssl/dist/doc/ssl/SSL_get_session.pod (revision ebfedea0ce5bbe81e252ddf32d732e40fb633fae)
1*ebfedea0SLionel Sambuc=pod
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3*ebfedea0SLionel Sambuc=head1 NAME
4*ebfedea0SLionel Sambuc
5*ebfedea0SLionel SambucSSL_get_session - retrieve TLS/SSL session data
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7*ebfedea0SLionel Sambuc=head1 SYNOPSIS
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9*ebfedea0SLionel Sambuc #include <openssl/ssl.h>
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11*ebfedea0SLionel Sambuc SSL_SESSION *SSL_get_session(const SSL *ssl);
12*ebfedea0SLionel Sambuc SSL_SESSION *SSL_get0_session(const SSL *ssl);
13*ebfedea0SLionel Sambuc SSL_SESSION *SSL_get1_session(SSL *ssl);
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15*ebfedea0SLionel Sambuc=head1 DESCRIPTION
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17*ebfedea0SLionel SambucSSL_get_session() returns a pointer to the B<SSL_SESSION> actually used in
18*ebfedea0SLionel SambucB<ssl>. The reference count of the B<SSL_SESSION> is not incremented, so
19*ebfedea0SLionel Sambucthat the pointer can become invalid by other operations.
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21*ebfedea0SLionel SambucSSL_get0_session() is the same as SSL_get_session().
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23*ebfedea0SLionel SambucSSL_get1_session() is the same as SSL_get_session(), but the reference
24*ebfedea0SLionel Sambuccount of the B<SSL_SESSION> is incremented by one.
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26*ebfedea0SLionel Sambuc=head1 NOTES
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28*ebfedea0SLionel SambucThe ssl session contains all information required to re-establish the
29*ebfedea0SLionel Sambucconnection without a new handshake.
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31*ebfedea0SLionel SambucSSL_get0_session() returns a pointer to the actual session. As the
32*ebfedea0SLionel Sambucreference counter is not incremented, the pointer is only valid while
33*ebfedea0SLionel Sambucthe connection is in use. If L<SSL_clear(3)|SSL_clear(3)> or
34*ebfedea0SLionel SambucL<SSL_free(3)|SSL_free(3)> is called, the session may be removed completely
35*ebfedea0SLionel Sambuc(if considered bad), and the pointer obtained will become invalid. Even
36*ebfedea0SLionel Sambucif the session is valid, it can be removed at any time due to timeout
37*ebfedea0SLionel Sambucduring L<SSL_CTX_flush_sessions(3)|SSL_CTX_flush_sessions(3)>.
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39*ebfedea0SLionel SambucIf the data is to be kept, SSL_get1_session() will increment the reference
40*ebfedea0SLionel Sambuccount, so that the session will not be implicitly removed by other operations
41*ebfedea0SLionel Sambucbut stays in memory. In order to remove the session
42*ebfedea0SLionel SambucL<SSL_SESSION_free(3)|SSL_SESSION_free(3)> must be explicitly called once
43*ebfedea0SLionel Sambucto decrement the reference count again.
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45*ebfedea0SLionel SambucSSL_SESSION objects keep internal link information about the session cache
46*ebfedea0SLionel Sambuclist, when being inserted into one SSL_CTX object's session cache.
47*ebfedea0SLionel SambucOne SSL_SESSION object, regardless of its reference count, must therefore
48*ebfedea0SLionel Sambuconly be used with one SSL_CTX object (and the SSL objects created
49*ebfedea0SLionel Sambucfrom this SSL_CTX object).
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51*ebfedea0SLionel Sambuc=head1 RETURN VALUES
52*ebfedea0SLionel Sambuc
53*ebfedea0SLionel SambucThe following return values can occur:
54*ebfedea0SLionel Sambuc
55*ebfedea0SLionel Sambuc=over 4
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57*ebfedea0SLionel Sambuc=item NULL
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59*ebfedea0SLionel SambucThere is no session available in B<ssl>.
60*ebfedea0SLionel Sambuc
61*ebfedea0SLionel Sambuc=item Pointer to an SSL
62*ebfedea0SLionel Sambuc
63*ebfedea0SLionel SambucThe return value points to the data of an SSL session.
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65*ebfedea0SLionel Sambuc=back
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67*ebfedea0SLionel Sambuc=head1 SEE ALSO
68*ebfedea0SLionel Sambuc
69*ebfedea0SLionel SambucL<ssl(3)|ssl(3)>, L<SSL_free(3)|SSL_free(3)>,
70*ebfedea0SLionel SambucL<SSL_clear(3)|SSL_clear(3)>,
71*ebfedea0SLionel SambucL<SSL_SESSION_free(3)|SSL_SESSION_free(3)>
72*ebfedea0SLionel Sambuc
73*ebfedea0SLionel Sambuc=cut
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