d2i_SSL_SESSION(3)d2i_SSL_SESSION(3)NAME
d2i_SSL_SESSION, i2d_SSL_SESSION - Convert SSL_SESSION object to or
from 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
The d2i_SSL_SESSION() function transforms the external ASN1 representa‐
tion of an SSL/TLS session, stored as binary data at location pp with
length length, into an SSL_SESSION object.
The i2d_SSL_SESSION() function 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() parts. Therefore,
it cannot be moved, copied or stored directly. In order to store ses‐
sion 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(), unless the SSL_SESSION
object is completely taken over, when being called inside the get_ses‐
sion_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. Therefore, one
SSL_SESSION object, regardless of its reference count, must 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 allo‐
cate the memory and call i2d_SSL_SESSION() again.
RETURN VALUES
The d2i_SSL_SESSION() function 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.
The i2d_SSL_SESSION() function returns the size of the ASN1 representa‐
tion in bytes. When the session is not valid, 0 is returned and no
operation is performed.
SEE ALSO
Functions: ssl(3), SSL_SESSION_free(3)SSL_CTX_sess_set_get_cb(3)d2i_SSL_SESSION(3)