tls_session.c

[詳解]

/*++
/* NAME
/*  tls_session
/* SUMMARY
/*  TLS client and server session routines
/* SYNOPSIS
/*  #include <tls.h>
/*
/*  void    tls_session_stop(ctx, stream, timeout, failure, TLScontext)
/*  TLS_APPL_STATE *ctx;
/*  VSTREAM *stream;
/*  int timeout;
/*  int failure;
/*  TLS_SESS_STATE *TLScontext;
/*
/*  VSTRING *tls_session_passivate(session)
/*  SSL_SESSION *session;
/*
/*  SSL_SESSION *tls_session_activate(session_data, session_data_len)
/*  char    *session_data;
/*  int session_data_len;
/* DESCRIPTION
/*  tls_session_stop() implements the tls_server_shutdown()
/*  and the tls_client_shutdown() routines.
/*
/*  tls_session_passivate() converts an SSL_SESSION object to
/*  VSTRING. The result is a null pointer in case of problems,
/*  otherwise it should be disposed of with vstring_free().
/*
/*  tls_session_activate() reanimates a passivated SSL_SESSION object.
/*  The result is a null pointer in case of problems,
/*  otherwise it should be disposed of with SSL_SESSION_free().
/* LICENSE
/* .ad
/* .fi
/*  This software is free. You can do with it whatever you want.
/*  The original author kindly requests that you acknowledge
/*  the use of his software.
/* AUTHOR(S)
/*  Originally written by:
/*  Lutz Jaenicke
/*  BTU Cottbus
/*  Allgemeine Elektrotechnik
/*  Universitaetsplatz 3-4
/*  D-03044 Cottbus, Germany
/*
/*  Updated by:
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*
/*  Victor Duchovni
/*  Morgan Stanley
/*--*/

/* System library. */

#include <sys_defs.h>

#ifdef USE_TLS

/* Utility library. */

#include <vstream.h>
#include <msg.h>
#include <mymalloc.h>

/* TLS library. */

#define TLS_INTERNAL
#include <tls.h>

/* Application-specific. */

#define STR vstring_str

/* tls_session_stop - shut down the TLS connection and reset state */

void    tls_session_stop(TLS_APPL_STATE *unused_ctx, VSTREAM *stream, int timeout,
                     int failure, TLS_SESS_STATE *TLScontext)
{
    const char *myname = "tls_session_stop";
    int     retval;

    /*
     * Sanity check.
     */
    if (TLScontext == 0)
    msg_panic("%s: stream has no active TLS context", myname);

    /*
     * Perform SSL_shutdown() twice, as the first attempt will send out the
     * shutdown alert but it will not wait for the peer's shutdown alert.
     * Therefore, when we are the first party to send the alert, we must call
     * SSL_shutdown() again. On failure we don't want to resume the session,
     * so we will not perform SSL_shutdown() and the session will be removed
     * as being bad.
     */
    if (!failure) {
    retval = tls_bio_shutdown(vstream_fileno(stream), timeout, TLScontext);
    if (retval == 0)
        tls_bio_shutdown(vstream_fileno(stream), timeout, TLScontext);
    }
    tls_free_context(TLScontext);
    tls_stream_stop(stream);
}

/* tls_session_passivate - passivate SSL_SESSION object */

VSTRING *tls_session_passivate(SSL_SESSION *session)
{
    const char *myname = "tls_session_passivate";
    int     estimate;
    int     actual_size;
    VSTRING *session_data;
    unsigned char *ptr;

    /*
     * First, find out how much memory is needed for the passivated
     * SSL_SESSION object.
     */
    estimate = i2d_SSL_SESSION(session, (unsigned char **) 0);
    if (estimate <= 0) {
    msg_warn("%s: i2d_SSL_SESSION failed: unable to cache session", myname);
    return (0);
    }

    /*
     * Passivate the SSL_SESSION object. The use of a VSTRING is slightly
     * wasteful but is convenient to combine data and length.
     */
    session_data = vstring_alloc(estimate);
    ptr = (unsigned char *) STR(session_data);
    actual_size = i2d_SSL_SESSION(session, &ptr);
    if (actual_size != estimate) {
    msg_warn("%s: i2d_SSL_SESSION failed: unable to cache session", myname);
    vstring_free(session_data);
    return (0);
    }
    VSTRING_AT_OFFSET(session_data, actual_size);   /* XXX not public */

    return (session_data);
}

/* tls_session_activate - activate passivated session */

SSL_SESSION *tls_session_activate(const char *session_data, int session_data_len)
{
#if (OPENSSL_VERSION_NUMBER < 0x0090707fL)
#define BOGUS_CONST
#else
#define BOGUS_CONST const
#endif
    SSL_SESSION *session;
    BOGUS_CONST unsigned char *ptr;

    /*
     * Activate the SSL_SESSION object.
     */
    ptr = (BOGUS_CONST unsigned char *) session_data;
    session = d2i_SSL_SESSION((SSL_SESSION **) 0, &ptr, session_data_len);
    if (!session)
    tls_print_errors();

    return (session);
}

#endif