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, 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)
