start_tls.c File Reference

Start TLS asynchronously. More...

#include <freeradius-devel/ldap/base.h>
#include <freeradius-devel/util/debug.h>

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Data Structures
struct	fr_ldap_start_tls_ctx_t
	Holds arguments for the start_tls operation. More...

Functions
static void	_ldap_start_tls_io_error (UNUSED fr_event_list_t *el, UNUSED int fd, UNUSED int flags, UNUSED int fd_errno, void *uctx)
	Error reading from or writing to the file descriptor. More...
static void	_ldap_start_tls_io_read (UNUSED fr_event_list_t *el, UNUSED int fd, UNUSED int flags, void *uctx)
	Event handler for the response to the StartTLS extended operation. More...
static void	_ldap_start_tls_io_write (fr_event_list_t *el, int fd, UNUSED int flags, void *uctx)
	Send an extended operation to the LDAP server, requesting a transition to TLS. More...
int	fr_ldap_start_tls_async (fr_ldap_connection_t *c, LDAPControl **serverctrls, LDAPControl **clientctrls)
	Install I/O handlers for Start TLS negotiation. More...

Detailed Description

Start TLS asynchronously.

Id

527ba041343b8d0c06061207fc2e4770af26371e

Copyright

2017 Arran Cudbard-Bell (a.cud.nosp@m.bard.nosp@m.b@fre.nosp@m.erad.nosp@m.ius.o.nosp@m.rg)

Id

9f91571b54eac96b575d5c003896badaaa882337

Copyright

2017 Arran Cudbard-Bell (a.cud.nosp@m.bard.nosp@m.b@fre.nosp@m.erad.nosp@m.ius.o.nosp@m.rg)

Definition in file start_tls.c.

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Data Structure Documentation

fr_ldap_start_tls_ctx_t

struct fr_ldap_start_tls_ctx_t

Holds arguments for the start_tls operation.

Definition at line 34 of file start_tls.c.

Collaboration diagram for fr_ldap_start_tls_ctx_t:

Data Fields
fr_ldap_connection_t *	c	The current connection.
LDAPControl **	clientctrls	Controls to pass to the client (library).
int	msgid
LDAPControl **	serverctrls	Controls to pass to the server.

Function Documentation

_ldap_start_tls_io_error()

static void _ldap_start_tls_io_error ( UNUSED fr_event_list_t *  el, UNUSED int  fd, UNUSED int  flags, UNUSED int  fd_errno, void *  uctx  )

static

Error reading from or writing to the file descriptor.

Parameters

[in]	el	the event occurred in.
[in]	fd	the event occurred on.
[in]	flags	from kevent.
[in]	fd_errno	The error that occurred.
[in]	uctx	Connection config and handle.

Definition at line 50 of file start_tls.c.

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_ldap_start_tls_io_read()

static void _ldap_start_tls_io_read ( UNUSED fr_event_list_t *  el, UNUSED int  fd, UNUSED int  flags, void *  uctx  )

static

Event handler for the response to the StartTLS extended operation.

Call flow is:

• ldap_install_tls
  • calls ldap_pvt_tls_inplace to check is the Sockbuf for defconn has TLS installed
    • If it does (it shouldn't), returns LDAP_LOCAL_ERROR (and we fail).
  • calls ldap_int_tls_start.
    • calls tls_init (to initialise ssl library - only done once per implementation).
    • if net timeout is >= 0, then set the FD to nonblocking mode.
    • calls ldap_int_tls_connect
      • either gets existing session or
        • installs sockbuff shims to do tls encode/decode.
        • calls connect callback
      • calls ->ti_session_connect (ssl library callback)
        • calls tlso_session_connect (openssl shim)
          • calls SSL_connect - SSL_connect can be called multiple times to continue session negotiation. returns 0 on success, -1 on error.
      • on -1, calls update_flags, which calls tlso_session_upflags
        • calls SSL_get_error, which returns SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE, SSL_ERROR_WANT_CONNECT, or another error. If error code is one of the above returns 1, else returns 0. Sets sb->sb_trans_needs_read or sb->sb_trans_needs_write.
      • if update_flags returns 1 ldap_int_tls_connect returns 1.
    • calls ldap_int_poll to check for errors.
  • returns LDAP_TIMEOUT if no data is available and we hit the timeout.

So unfortunately ldap_install_tls is blocking... We need to send patches to OpenLDAP in order to fix that.

Parameters

[in]	el	the event occurred in.
[in]	fd	the event occurred on.
[in]	flags	from kevent.
[in]	uctx	Connection config and handle.

Definition at line 96 of file start_tls.c.

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_ldap_start_tls_io_write()

static void _ldap_start_tls_io_write ( fr_event_list_t *  el, int  fd, UNUSED int  flags, void *  uctx  )

static

Send an extended operation to the LDAP server, requesting a transition to TLS.

Behind the scenes ldap_start_tls calls:

 ldap_extended_operation(ld, LDAP_EXOP_START_TLS, NULL, serverctrls, clientctrls, msgidp);

Parameters

[in]	el	the event occurred in.
[in]	fd	the event occurred on.
[in]	flags	from kevent.
[in]	uctx	Connection config and handle.

Definition at line 149 of file start_tls.c.

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fr_ldap_start_tls_async()

int fr_ldap_start_tls_async	(	fr_ldap_connection_t *	c,
		LDAPControl **	serverctrls,
		LDAPControl **	clientctrls
	)

Install I/O handlers for Start TLS negotiation.

Parameters

[in]	c	connection to StartTLS on.
[in]	serverctrls	Extra controls to pass to the server.
[in]	clientctrls	Extra controls to pass to libldap.

Returns

• 0 on success.
• -1 on failure.

Definition at line 222 of file start_tls.c.

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