Misc fix ups to deprecate explicit de-init documentation

[openssl.git] / doc / ssl / d2i_SSL_SESSION.pod

diff --git a/doc/ssl/d2i_SSL_SESSION.pod b/doc/ssl/d2i_SSL_SESSION.pod
index 8142b6b39f75d839b38b4266a64de74bb6a70ed5..985d1580f9bc8f5cc904abb5a74714d80addf441 100644 (file)
--- a/doc/ssl/d2i_SSL_SESSION.pod
+++ b/doc/ssl/d2i_SSL_SESSION.pod
@@ -1,13 +1,14 @@
 =pod
 
 =head1 NAME
+
 d2i_SSL_SESSION, i2d_SSL_SESSION - convert SSL_SESSION object from/to ASN1 representation
 
 =head1 SYNOPSIS
 
  #include <openssl/ssl.h>
 
- SSL_SESSION *d2i_SSL_SESSION(SSL_SESSION **a, unsigned char **pp, long length);
+ SSL_SESSION *d2i_SSL_SESSION(SSL_SESSION **a, const unsigned char **pp, long length);
  int i2d_SSL_SESSION(SSL_SESSION *in, unsigned char **pp);
 
 =head1 DESCRIPTION
@@ -29,7 +30,17 @@ 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.
+allocated. The reference count is 1, so that the session must be
+explicitly removed using L<SSL_SESSION_free(3)>,
+unless the SSL_SESSION object is completely taken over, when being called
+inside the get_session_cb() (see
+L<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 B<pp> must be
 large enough to hold the binary representation of the session. There is no
@@ -37,6 +48,16 @@ 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
 B<pp=NULL>, and obtain the size needed, then allocate the memory and
 call i2d_SSL_SESSION() again.
+Note that this will advance the value contained in B<*pp> so it is necessary
+to save a copy of the original allocation.
+For example:
+ int i,j;
+ char *p, *temp;
+ i = i2d_SSL_SESSION(sess, NULL);
+ p = temp = malloc(i);
+ j = i2d_SSL_SESSION(sess, &temp);
+ assert(i == j);
+ assert(p+i == temp);
 
 =head1 RETURN VALUES
 
@@ -49,7 +70,7 @@ When the session is not valid, B<0> is returned and no operation is performed.
 
 =head1 SEE ALSO
 
-L<ssl(3)|ssl(3)>,
-L<SSL_CTX_sess_set_get_cb(3)|SSL_CTX_sess_set_get_cb(3)>
+L<ssl(3)>, L<SSL_SESSION_free(3)>,
+L<SSL_CTX_sess_set_get_cb(3)>
 
 =cut