NAME

       d2i_SSL_SESSION, i2d_SSL_SESSION - convert SSL_SESSION object from/to ASN1 representation

SYNOPSIS

        #include <openssl/ssl.h>

        SSL_SESSION *d2i_SSL_SESSION(SSL_SESSION **a, const unsigned char **pp, long length);
        int i2d_SSL_SESSION(SSL_SESSION *in, unsigned char **pp);

DESCRIPTION

       d2i_SSL_SESSION() transforms the external ASN1 representation of an SSL/TLS session,
       stored as binary data at location pp with length length, into an SSL_SESSION object.

       i2d_SSL_SESSION() transforms the SSL_SESSION object in into the ASN1 representation and
       stores it into the memory location pointed to by pp.  The length of the resulting ASN1
       representation is returned. If pp is the NULL pointer, only the length is calculated and
       returned.

NOTES

       The SSL_SESSION object is built from several malloc()ed parts, it can therefore not be
       moved, copied or stored directly. In order to store session data on disk or into a
       database, it must be transformed into a binary ASN1 representation.

       When using d2i_SSL_SESSION(), the SSL_SESSION object is automatically allocated. The
       reference count is 1, so that the session must be explicitly removed using
       SSL_SESSION_free(3), unless the SSL_SESSION object is completely taken over, when being
       called inside the get_session_cb() (see SSL_CTX_sess_set_get_cb(3)).

       SSL_SESSION objects keep internal link information about the session cache list, when
       being inserted into one SSL_CTX object's session cache.  One SSL_SESSION object,
       regardless of its reference count, must therefore only be used with one SSL_CTX object
       (and the SSL objects created from this SSL_CTX object).

       When using i2d_SSL_SESSION(), the memory location pointed to by pp must be large enough to
       hold the binary representation of the session. There is no known limit on the size of the
       created ASN1 representation, so the necessary amount of space should be obtained by first
       calling i2d_SSL_SESSION() with pp=NULL, and obtain the size needed, then allocate the
       memory and call i2d_SSL_SESSION() again.

RETURN VALUES

       d2i_SSL_SESSION() returns a pointer to the newly allocated SSL_SESSION object. In case of
       failure the NULL-pointer is returned and the error message can be retrieved from the error
       stack.

       i2d_SSL_SESSION() returns the size of the ASN1 representation in bytes.  When the session
       is not valid, 0 is returned and no operation is performed.

SEE ALSO

       ssl(3), SSL_SESSION_free(3), SSL_CTX_sess_set_get_cb(3)