ldap/ssldap/ldapsinit.c

/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation. Portions created by Netscape are
 * Copyright (C) 1998-1999 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s):
 */

/*
 * ldapsinit.c
 */

#if defined(NET_SSL)

#if defined( _WINDOWS )
#include <windows.h>
#endif

/* XXX:mhein The following is a workaround for the redefinition of */
/*           const problem on OSF.  Fix to be provided by NSS */
/*           This is a pretty benign workaround for us which */
/*           should not cause problems in the future even if */
/*           we forget to take it out :-) */

#ifdef OSF1V4D
#ifndef __STDC__
#  define __STDC__
#endif /* __STDC__ */
#endif /* OSF1V4D */

#include <errno.h>
#include <nspr.h>
#include <cert.h>
#include <key.h>
#include <ssl.h>
#include <sslproto.h>
#include <sslerr.h>
#include <prnetdb.h>

#include <ldap.h>

#include <ldappr.h>
#include <pk11func.h>

#ifdef _SOLARIS_SDK
#include "solaris-int.h"
#include <libintl.h>
#include <syslog.h>
#include <nsswitch.h>
#include <synch.h>
#include <nss_dbdefs.h>
#include <netinet/in.h>

#define	HOST_BUF_SIZE	2048

#ifndef INADDR_NONE
#define	INADDR_NONE (-1)
#endif

extern int
str2hostent(const char *instr, int lenstr, void *ent, char *buffer,
		int buflen);

extern int
str2hostent6(const char *instr, int lenstr, void *ent, char *buffer,
		int buflen);

extern LDAPHostEnt *
_ns_gethostbyaddr(LDAP *ld, const char *addr, int length, int type,
	LDAPHostEnt *result, char *buffer, int buflen, int *statusp,
	void *extradata);

static char *host_service = NULL;

static DEFINE_NSS_DB_ROOT(db_root_hosts);
static DEFINE_NSS_DB_ROOT(db_root_ipnodes);
#endif

/*
 * Data structure to hold the standard NSPR I/O function pointers set by
 * libprldap.   We save them in our session data structure so we can call
 * them from our own I/O functions (we add functionality to support SSL
 * while using libprldap's functions as much as possible).
 */
typedef struct ldapssl_std_functions {
    LDAP_X_EXTIOF_CLOSE_CALLBACK		*lssf_close_fn;
    LDAP_X_EXTIOF_CONNECT_CALLBACK		*lssf_connect_fn;
    LDAP_X_EXTIOF_DISPOSEHANDLE_CALLBACK	*lssf_disposehdl_fn;
} LDAPSSLStdFunctions;


/*
 * LDAP session data structure.
 */
typedef struct ldapssl_session_info {
    int                 lssei_using_pcks_fns;
    int                 lssei_ssl_strength;
    char                *lssei_certnickname;
    char                *lssei_keypasswd;
    LDAPSSLStdFunctions lssei_std_functions;
    CERTCertDBHandle    *lssei_certdbh;
#ifdef _SOLARIS_SDK
	/*
	 * This is a hack.
	 * ld is used so that we can use libldap's gethostbyaddr
	 * resolver. This is needed to prevent recursion with libsldap.
	 */
    LDAP		*ld;
#endif	/* _SOLARIS_SDK */
} LDAPSSLSessionInfo;


/*
 * LDAP socket data structure.
 */
typedef struct ldapssl_socket_info {
    LDAPSSLSessionInfo	*soi_sessioninfo;	/* session info */
} LDAPSSLSocketInfo;


/*
 * XXXceb  This is a hack until the new IO functions are done.
 * this function MUST be called before ldap_enable_clienauth.
 * right now, this function is called in ldapssl_pkcs_init();
 */

static int using_pkcs_functions = 0;

void set_using_pkcs_functions( int val )
{
    using_pkcs_functions = val;
}


/*
 * Utility functions:
 */
static void ldapssl_free_session_info( LDAPSSLSessionInfo **ssipp );
static void ldapssl_free_socket_info( LDAPSSLSocketInfo **soipp );


/*
 *  SSL Stuff
 */

static int ldapssl_AuthCertificate(void *sessionarg, PRFileDesc *fd,
        PRBool checkSig, PRBool isServer);

/*
 * client auth stuff
 */
static int get_clientauth_data( void *sessionarg, PRFileDesc *prfd,
	CERTDistNames *caNames,  CERTCertificate **pRetCert,
	SECKEYPrivateKey **pRetKey );
static int get_keyandcert( LDAPSSLSessionInfo *ssip,
	CERTCertificate **pRetCert, SECKEYPrivateKey **pRetKey,
	char **errmsgp );
static int check_clientauth_nicknames_and_passwd( LDAP *ld,
	LDAPSSLSessionInfo *ssip );
static char *get_keypassword( PK11SlotInfo *slot, PRBool retry,
	void *sessionarg );

/*
 * Static variables.
 */
#ifdef _SOLARIS_SDK
static int default_ssl_strength = LDAPSSL_AUTH_CNCHECK;
#else
static int default_ssl_strength = LDAPSSL_AUTH_CERT;
#endif

/*
 * Like ldap_init(), except also install I/O routines from libsec so we
 * can support SSL.  If defsecure is non-zero, SSL is enabled for the
 * default connection as well.
 */
LDAP *
LDAP_CALL
ldapssl_init( const char *defhost, int defport, int defsecure )
{
    LDAP	*ld;


#ifndef LDAP_SSLIO_HOOKS
    return( NULL );
#else
    if (0 ==defport)
	defport = LDAPS_PORT;

    if (( ld = ldap_init( defhost, defport )) == NULL ) {
	return( NULL );
    }

    if ( ldapssl_install_routines( ld ) < 0 || ldap_set_option( ld,
		LDAP_OPT_SSL, defsecure ? LDAP_OPT_ON : LDAP_OPT_OFF ) != 0 ) {
	PR_SetError( PR_UNKNOWN_ERROR, EINVAL );  /* XXXmcs: just a guess! */
	ldap_unbind( ld );
	return( NULL );
    }

    return( ld );
#endif
}


static int
ldapssl_close(int s, struct lextiof_socket_private *socketarg)
{
    PRLDAPSocketInfo	soi;
    LDAPSSLSocketInfo	*ssoip;
    LDAPSSLSessionInfo	*sseip;

    memset( &soi, 0, sizeof(soi));
    soi.soinfo_size = PRLDAP_SOCKETINFO_SIZE;
    if ( prldap_get_socket_info( s, socketarg, &soi ) != LDAP_SUCCESS ) {
	return( -1 );
    }

    ssoip = (LDAPSSLSocketInfo *)soi.soinfo_appdata;
    sseip = ssoip->soi_sessioninfo;

    ldapssl_free_socket_info( (LDAPSSLSocketInfo **)&soi.soinfo_appdata );

    return( (*(sseip->lssei_std_functions.lssf_close_fn))( s, socketarg ));
}

static int
do_ldapssl_connect(const char *hostlist, int defport, int timeout,
	unsigned long options, struct lextiof_session_private *sessionarg,
	struct lextiof_socket_private **socketargp, int clientauth )
{
    int			intfd = -1;
    PRBool		secure;
    PRLDAPSessionInfo	sei;
    PRLDAPSocketInfo	soi;
    LDAPSSLSocketInfo	*ssoip = NULL;
    LDAPSSLSessionInfo	*sseip;
    PRFileDesc		*sslfd = NULL;
#ifdef _SOLARIS_SDK
    int			port;
    int			parse_err;
    char		*host = NULL;
    char		*name;
    struct ldap_x_hostlist_status
			*status = NULL;
    in_addr_t		addr_ipv4;
    in6_addr_t		addr_ipv6;
    char		*host_buf;
    LDAPHostEnt		*hent;
    LDAPHostEnt		host_ent;
    int			stat;
    int			type;
#endif	/* _SOLARIS_SDK */

    /*
     * Determine if secure option is set.  Also, clear secure bit in options
     * the we pass to the standard connect() function (since it doesn't know
     * how to handle the secure option).
     */
    if ( 0 != ( options & LDAP_X_EXTIOF_OPT_SECURE )) {
	secure = PR_TRUE;
	options &= ~LDAP_X_EXTIOF_OPT_SECURE;
    } else {
	secure = PR_FALSE;
    }

    /*
     * Retrieve session info. so we can store a pointer to our session info.
     * in our socket info. later.
     */
    memset( &sei, 0, sizeof(sei));
    sei.seinfo_size = PRLDAP_SESSIONINFO_SIZE;
    if ( prldap_get_session_info( NULL, sessionarg, &sei ) != LDAP_SUCCESS ) {
	return( -1 );
    }
    sseip = (LDAPSSLSessionInfo *)sei.seinfo_appdata;

    /*
     * Call the standard connect() callback to make the TCP connection.
     * If it succeeds, *socketargp is set.
     */

    intfd = (*(sseip->lssei_std_functions.lssf_connect_fn))( hostlist, defport,
		timeout, options, sessionarg, socketargp
#ifdef _SOLARIS_SDK
		, &host );
#else
		);
#endif	/* _SOLARIS_SDK */

    if ( intfd < 0 ) {
	return( intfd );
    }

#ifdef _SOLARIS_SDK
        /*
         * Determine if the "host name" is an ip address. If so,
         * we must look up the actual host name corresponding to
         * it.
         */
	if ( NULL == host ) {
		goto close_socket_and_exit_with_error;
	}
        type = AF_UNSPEC;
        if (strlen(host) < INET6_ADDRSTRLEN &&
                        inet_pton(AF_INET6, host, &addr_ipv6) == 1) {
                type = AF_INET6;
        } else if (strlen(host) < INET_ADDRSTRLEN &&
                        inet_pton(AF_INET, host, &addr_ipv4) == 1) {
                type = AF_INET;
        }
        if (type == AF_INET || type == AF_INET6) {
                host_buf = malloc(HOST_BUF_SIZE);
                if (host_buf == NULL) {
			/* will free host in close_socket_and_exit_with_error */
                        goto close_socket_and_exit_with_error;
		}

                /* Call ldap layer's gethostbyaddr resolver */
                hent = _ns_gethostbyaddr(sseip->ld, host, strlen(host), type,
                        &host_ent, host_buf, HOST_BUF_SIZE, &stat, NULL);

                /* If we are unable to lookup the host addr, we fail! */
                if (hent == NULL) {
                        syslog(LOG_WARNING,
                                "libldap: do_ldapssl_connect: "
                                "Unable to resolve '%s'", host);
                        free(host_buf);
			/* will free host in close_socket_and_exit_with_error */
			goto close_socket_and_exit_with_error;
                }
                /* We support only the primary host name */
                else {
			if (hent->ldaphe_name != NULL)
                        	name = strdup(hent->ldaphe_name);
                	free(host_buf);
                	if (name == NULL)
                        	goto close_socket_and_exit_with_error;
			else
                		ldap_memfree(host); host = NULL;
                	host = name;
		}
        }
#endif	/* _SOLARIS_SDK */

    /*
     * Retrieve socket info. so we have the PRFileDesc.
     */
    memset( &soi, 0, sizeof(soi));
    soi.soinfo_size = PRLDAP_SOCKETINFO_SIZE;
    if ( prldap_get_socket_info( intfd, *socketargp, &soi ) != LDAP_SUCCESS ) {
	goto close_socket_and_exit_with_error;
    }

    /*
     * Allocate a structure to hold our socket-specific data.
     */
    if ( NULL == ( ssoip = PR_Calloc( 1, sizeof( LDAPSSLSocketInfo )))) {
	goto close_socket_and_exit_with_error;
    }
    ssoip->soi_sessioninfo = sseip;

    /*
     * Add SSL layer and let the standard NSPR to LDAP layer and enable SSL.
     */
    if (( sslfd = SSL_ImportFD( NULL, soi.soinfo_prfd )) == NULL ) {
	goto close_socket_and_exit_with_error;
    }

    if ( SSL_OptionSet( sslfd, SSL_SECURITY, secure ) != SECSuccess ||
		SSL_OptionSet( sslfd, SSL_HANDSHAKE_AS_CLIENT, secure )
		!= SECSuccess || ( secure && SSL_ResetHandshake( sslfd,
		PR_FALSE ) != SECSuccess )) {
	goto close_socket_and_exit_with_error;
    }

    /*
     * Let the standard NSPR to LDAP layer know about the new socket and
     * our own socket-specific data.
     */
    soi.soinfo_prfd = sslfd;
    soi.soinfo_appdata = (void *)ssoip;
    if ( prldap_set_socket_info( intfd, *socketargp, &soi ) != LDAP_SUCCESS ) {
	goto close_socket_and_exit_with_error;
    }

#ifdef _SOLARIS_SDK
    /*
     * Set hostname which will be retrieved (depending on ssl strength) when
     * using client or server auth.
     */
    if (SSL_SetURL(sslfd, host) != SECSuccess)
	goto close_socket_and_exit_with_error;
    ldap_memfree(host);
    host = NULL;
#endif /* _SOLARIS_SDK */

    sslfd = NULL;	/* so we don't close the socket twice upon error */

    /*
     * Install certificate hook function.
     */
    SSL_AuthCertificateHook( soi.soinfo_prfd,
			     (SSLAuthCertificate)ldapssl_AuthCertificate,
                             (void *)sseip);

    if ( SSL_GetClientAuthDataHook( soi.soinfo_prfd,
		get_clientauth_data, clientauth ? sseip : NULL ) != 0 ) {
	goto close_socket_and_exit_with_error;
    }

    return( intfd );	/* success */

close_socket_and_exit_with_error:
#ifdef _SOLARIS_SDK
    if ( NULL != host ) ldap_memfree(host);
#endif /* _SOLARIS_SDK */
    if ( NULL != sslfd ) {
	PR_Close( sslfd );
    }
    if ( NULL != ssoip ) {
	ldapssl_free_socket_info( &ssoip );
    }
    if ( intfd >= 0 && NULL != *socketargp ) {
	(*(sseip->lssei_std_functions.lssf_close_fn))( intfd, *socketargp );
    }
    return( -1 );
}


static int
ldapssl_connect(const char *hostlist, int defport, int timeout,
	unsigned long options, struct lextiof_session_private *sessionarg,
	struct lextiof_socket_private **socketargp )
{
    return( do_ldapssl_connect( hostlist, defport, timeout, options,
		sessionarg, socketargp, 0 ));
}


static int
ldapssl_clientauth_connect(const char *hostlist, int defport, int timeout,
	unsigned long options, struct lextiof_session_private *sessionarg,
	struct lextiof_socket_private **socketargp )
{
    return( do_ldapssl_connect( hostlist, defport, timeout, options,
		sessionarg, socketargp, 1 ));
}


static void
ldapssl_disposehandle(LDAP *ld, struct lextiof_session_private *sessionarg)
{
    PRLDAPSessionInfo				sei;
    LDAPSSLSessionInfo				*sseip;
    LDAP_X_EXTIOF_DISPOSEHANDLE_CALLBACK	*disposehdl_fn;

    memset( &sei, 0, sizeof( sei ));
    sei.seinfo_size = PRLDAP_SESSIONINFO_SIZE;
    if ( prldap_get_session_info( ld, NULL, &sei ) == LDAP_SUCCESS ) {
	sseip = (LDAPSSLSessionInfo *)sei.seinfo_appdata;
	disposehdl_fn = sseip->lssei_std_functions.lssf_disposehdl_fn;
	ldapssl_free_session_info( &sseip );
	(*disposehdl_fn)( ld, sessionarg );
    }
}


/*
 * Install I/O routines from libsec and NSPR into libldap to allow libldap
 * to do SSL.
 *
 * We rely on libprldap to provide most of the functions, and then we override
 * a few of them to support SSL.
 */
int
LDAP_CALL
ldapssl_install_routines( LDAP *ld )
{
#ifndef LDAP_SSLIO_HOOKS
    ldap_set_lderrno( ld, LDAP_LOCAL_ERROR, NULL, NULL );
    return( -1 );
#else
    struct ldap_x_ext_io_fns	iofns;
    LDAPSSLSessionInfo		*ssip;
    PRLDAPSessionInfo		sei;

/*
 * This is done within ldap_init() and
 * ldap_init() is called from ldapssl_init()
 */
#ifndef _SOLARIS_SDK
    if ( prldap_install_routines(
		ld,
		1 /* shared -- we have to assume it is */ )
		!= LDAP_SUCCESS ) {
	return( -1 );
    }
#endif /*_SOLARIS_SDK*/

    /*
     * Allocate our own session information.
     */
    if ( NULL == ( ssip = (LDAPSSLSessionInfo *)PR_Calloc( 1,
		sizeof( LDAPSSLSessionInfo )))) {
	ldap_set_lderrno( ld, LDAP_NO_MEMORY, NULL, NULL );
	return( -1 );
    }
    /*
     * Initialize session info.
     * XXX: it would be nice to be able to set these on a per-session basis:
     *          lssei_using_pcks_fns
     *          lssei_certdbh
     */
    ssip->lssei_ssl_strength = default_ssl_strength;
    ssip->lssei_using_pcks_fns = using_pkcs_functions;
    ssip->lssei_certdbh = CERT_GetDefaultCertDB();
#ifdef _SOLARIS_SDK
    /*
     * This is part of a hack to allow the ssl portion of the
     * library to call the ldap library gethostbyaddr resolver.
     */
    ssip->ld = ld;
#endif	/* _SOLARIS_SDK */

    /*
     * override a few functions, saving a pointer to the standard function
     * in each case so we can call it from our SSL savvy functions.
     */
    memset( &iofns, 0, sizeof(iofns));
    iofns.lextiof_size = LDAP_X_EXTIO_FNS_SIZE;
    if ( ldap_get_option( ld, LDAP_X_OPT_EXTIO_FN_PTRS, (void *)&iofns ) < 0 ) {
	ldapssl_free_session_info( &ssip );
	return( -1 );
    }

    /* override socket, connect, and ioctl */
    ssip->lssei_std_functions.lssf_connect_fn = iofns.lextiof_connect;
    iofns.lextiof_connect = ldapssl_connect;
    ssip->lssei_std_functions.lssf_close_fn = iofns.lextiof_close;
    iofns.lextiof_close = ldapssl_close;
    ssip->lssei_std_functions.lssf_disposehdl_fn = iofns.lextiof_disposehandle;
    iofns.lextiof_disposehandle = ldapssl_disposehandle;

    if ( ldap_set_option( ld, LDAP_X_OPT_EXTIO_FN_PTRS, (void *)&iofns ) < 0 ) {
	ldapssl_free_session_info( &ssip );
	return( -1 );
    }

    /*
     * Store session info. for later retrieval.
     */
    sei.seinfo_size = PRLDAP_SESSIONINFO_SIZE;
    sei.seinfo_appdata = (void *)ssip;
    if ( prldap_set_session_info( ld, NULL, &sei ) != LDAP_SUCCESS ) {
	return( -1 );
    }

    return( 0 );
#endif
}


/*
 * Set the SSL strength for an existing SSL-enabled LDAP session handle.
 *
 * See the description of ldapssl_serverauth_init() above for valid
 * sslstrength values. If ld is NULL, the default for new LDAP session
 * handles is set.
 *
 * Returns 0 if all goes well and -1 if an error occurs.
 */
int
LDAP_CALL
ldapssl_set_strength( LDAP *ld, int sslstrength )
{
    int                 rc = 0; /* assume success */

    if ( sslstrength != LDAPSSL_AUTH_WEAK &&
                sslstrength != LDAPSSL_AUTH_CERT &&
                sslstrength != LDAPSSL_AUTH_CNCHECK ) {
        rc = -1;
    } else {
        if ( NULL == ld ) {     /* set default strength */
            default_ssl_strength = sslstrength;
        } else {                /* set session-specific strength */
            PRLDAPSessionInfo   sei;
            LDAPSSLSessionInfo  *sseip;

            memset( &sei, 0, sizeof( sei ));
            sei.seinfo_size = PRLDAP_SESSIONINFO_SIZE;
            if ( prldap_get_session_info( ld, NULL, &sei ) == LDAP_SUCCESS )
{
                sseip = (LDAPSSLSessionInfo *)sei.seinfo_appdata;
                sseip->lssei_ssl_strength = sslstrength;
            } else {
                rc = -1;
            }
        }
    }

    return( rc );
}

int
LDAP_CALL
ldapssl_enable_clientauth( LDAP *ld, char *keynickname,
        char *keypasswd, char *certnickname )
{
#ifndef LDAP_SSLIO_HOOKS
    ldap_set_lderrno( ld, LDAP_LOCAL_ERROR, NULL, NULL );
    return( -1 );
#else
    struct ldap_x_ext_io_fns	iofns;
    LDAPSSLSessionInfo		*ssip;
    PRLDAPSessionInfo		sei;

    /*
     * Check parameters
     */
    if ( certnickname == NULL || keypasswd == NULL ) {
	ldap_set_lderrno( ld, LDAP_PARAM_ERROR, NULL, NULL );
	return( -1 );
    }

    /*
     * Update session info. data structure.
     */
    sei.seinfo_size = PRLDAP_SESSIONINFO_SIZE;
    if ( prldap_get_session_info( ld, NULL, &sei ) != LDAP_SUCCESS ) {
	return( -1 );
    }
    ssip = (LDAPSSLSessionInfo *)sei.seinfo_appdata;
    if ( NULL == ssip ) {
	ldap_set_lderrno( ld, LDAP_PARAM_ERROR, NULL, NULL );
	return( -1 );
    }
    ssip->lssei_certnickname = PL_strdup( certnickname );
    ssip->lssei_keypasswd = PL_strdup( keypasswd );

    if ( NULL == ssip->lssei_certnickname || NULL == ssip->lssei_keypasswd ) {
	ldap_set_lderrno( ld, LDAP_NO_MEMORY, NULL, NULL );
	return( -1 );
    }

    if ( check_clientauth_nicknames_and_passwd( ld, ssip ) != 0 ) {
	return( -1 );
    }

    /*
     * replace standard SSL CONNECT function with client auth aware one
     */
    memset( &iofns, 0, sizeof(iofns));
    iofns.lextiof_size = LDAP_X_EXTIO_FNS_SIZE;
    if ( ldap_get_option( ld, LDAP_X_OPT_EXTIO_FN_PTRS, (void *)&iofns )
		!= 0 ) {
	return( -1 );
    }

    if ( iofns.lextiof_connect != ldapssl_connect ) {
	/* standard SSL setup has not done */
	ldap_set_lderrno( ld, LDAP_PARAM_ERROR, NULL, NULL );
	return( -1 );
    }

    iofns.lextiof_connect = ldapssl_clientauth_connect;

    if ( ldap_set_option( ld, LDAP_X_OPT_EXTIO_FN_PTRS, (void *)&iofns )
		!= 0 ) {
	return( -1 );
    }

    return( 0 );
#endif
}


static void
ldapssl_free_session_info( LDAPSSLSessionInfo **ssipp )
{
    if ( NULL != ssipp && NULL != *ssipp ) {
	if ( NULL != (*ssipp)->lssei_certnickname ) {
	    PL_strfree( (*ssipp)->lssei_certnickname );
	    (*ssipp)->lssei_certnickname = NULL;
	}
	if ( NULL != (*ssipp)->lssei_keypasswd ) {
	    PL_strfree( (*ssipp)->lssei_keypasswd );
	    (*ssipp)->lssei_keypasswd = NULL;
	}
	PR_Free( *ssipp );
	*ssipp = NULL;
    }
}


static void
ldapssl_free_socket_info( LDAPSSLSocketInfo **soipp )
{
    if ( NULL != soipp && NULL != *soipp ) {
	PR_Free( *soipp );
	*soipp = NULL;
    }
}


/* this function provides cert authentication.  This is called during
 * the SSL_Handshake process.  Once the cert has been retrieved from
 * the server, the it is checked, using VerifyCertNow(), then
 * the cn is checked against the host name, set with SSL_SetURL()
 */

static int
ldapssl_AuthCertificate(void *sessionarg, PRFileDesc *fd, PRBool checkSig,
	PRBool isServer)
{
    SECStatus		rv = SECFailure;
    LDAPSSLSessionInfo	*sseip;
    CERTCertificate	*cert;
    SECCertUsage	certUsage;
    char		*hostname = (char *)0;

    if (!sessionarg || !socket)
	return rv;

    sseip = (LDAPSSLSessionInfo *)sessionarg;

    if (LDAPSSL_AUTH_WEAK == sseip->lssei_ssl_strength ) { /* no check */
        return SECSuccess;
    }

    if ( isServer ) {
	certUsage = certUsageSSLClient;
    } else {
	certUsage = certUsageSSLServer;
    }
    cert = SSL_PeerCertificate( fd );

    rv = CERT_VerifyCertNow(sseip->lssei_certdbh, cert, checkSig,
			certUsage, NULL);

    if ( rv != SECSuccess || isServer )
	return rv;

    if ( LDAPSSL_AUTH_CNCHECK == sseip->lssei_ssl_strength )
      {
	/* cert is OK.  This is the client side of an SSL connection.
	 * Now check the name field in the cert against the desired hostname.
	 * NB: This is our only defense against Man-In-The-Middle (MITM)
	 * attacks!
	 */

	hostname = SSL_RevealURL( fd );

	if (hostname && hostname[0]) {
	  rv = CERT_VerifyCertName(cert, hostname);
	} else  {
	  rv = SECFailure;
     	}
	if (hostname)
		PORT_Free(hostname);
	if (rv != SECSuccess)
	  PORT_SetError(SSL_ERROR_BAD_CERT_DOMAIN);
      }

    return((int)rv);
}


/*
 * called during SSL client auth. when server wants our cert and key.
 * return 0 if we succeeded and set *pRetCert and *pRetKey, -1 otherwise.
 * if -1 is returned SSL will proceed without sending a cert.
 */

static int
get_clientauth_data( void *sessionarg, PRFileDesc *prfd,
        CERTDistNames *caNames,  CERTCertificate **pRetCert,
        SECKEYPrivateKey **pRetKey )

{
    LDAPSSLSessionInfo	*ssip;

    if (( ssip = (LDAPSSLSessionInfo *)sessionarg ) == NULL ) {
	return( -1 );       /* client auth. not enabled */
    }

    return( get_keyandcert( ssip, pRetCert, pRetKey, NULL ));
}

static int
get_keyandcert( LDAPSSLSessionInfo *ssip,
	CERTCertificate **pRetCert, SECKEYPrivateKey **pRetKey,
	char **errmsgp )
{
    CERTCertificate	*cert;
    SECKEYPrivateKey	*key;

    if (( cert = PK11_FindCertFromNickname( ssip->lssei_certnickname, NULL ))
		== NULL ) {
	if ( errmsgp != NULL ) {
	    *errmsgp = dgettext(TEXT_DOMAIN, "unable to find certificate");
	}
	return( -1 );
    }

    {
	PK11_SetPasswordFunc( get_keypassword );
    }


    if (( key = PK11_FindKeyByAnyCert( cert, (void *)ssip )) == NULL ) {
	CERT_DestroyCertificate( cert );
	if ( errmsgp != NULL ) {
	    *errmsgp = dgettext(TEXT_DOMAIN, "bad key or key password");
	}
	return( -1 );
    }

    *pRetCert = cert;
    *pRetKey = key;
    return( 0 );
}


/*
 * This function returns the password to NSS.
 * This function is enable through PK11_SetPasswordFunc
 * only if pkcs functions are not being used.
 */

static char *
get_keypassword( PK11SlotInfo *slot, PRBool retry, void *sessionarg )
{
    LDAPSSLSessionInfo	*ssip;

    if ( retry)
      return (NULL);

    ssip = (LDAPSSLSessionInfo *)sessionarg;
    if ( NULL == ssip ) {
	return( NULL );
    }

    return( ssip->lssei_keypasswd );
}


/*
 * performs some basic checks on clientauth cert and key/password
 *
 * XXXmcs: could perform additional checks... see servers/slapd/ssl.c
 *	1) check expiration
 *	2) check that public key in cert matches private key
 * see ns/netsite/ldap/servers/slapd/ssl.c:slapd_ssl_init() for example code.
 */
static int
check_clientauth_nicknames_and_passwd( LDAP *ld, LDAPSSLSessionInfo *ssip )
{
    char		*errmsg = NULL;
    CERTCertificate	*cert = NULL;
    SECKEYPrivateKey	*key = NULL;
    int rv;

    rv = get_keyandcert( ssip, &cert, &key, &errmsg );

    if ( rv != 0 ) {
    	if ( errmsg != NULL ) {
	    errmsg = strdup( errmsg );
	}
	ldap_set_lderrno( ld, LDAP_PARAM_ERROR, NULL, errmsg );
	return( -1 );
    }

    if ( cert != NULL ) {
	CERT_DestroyCertificate( cert );
    }
    if ( key != NULL ) {
	SECKEY_DestroyPrivateKey( key );
    }
    return( 0 );
}


#if 0	/* NOT_NEEDED_IN_LIBLDAP */
/* there are patches and kludges.  this is both.  force some linkers to
 * link this stuff in
 */
int stubs_o_stuff( void )
{
    PRExplodedTime exploded;
    PLArenaPool pool;

    const char *name ="t";
    PRUint32 size = 0, align = 0;

    PR_ImplodeTime( &exploded );
    PL_InitArenaPool( &pool, name, size, align);
    PR_Cleanup();
    PR_fprintf((PRFileDesc*)stderr, "Bad IDEA!!");

    return 0;

}
#endif	/* NOT_NEEDED_IN_LIBLDAP */


/*
 * Import the file descriptor corresponding to the socket of an already
 * open LDAP connection into SSL, and update the socket and session
 * information accordingly.
 */
int ldapssl_import_fd ( LDAP *ld, int secure )
{
    PRLDAPSessionInfo   sei;
    PRLDAPSocketInfo    soi;
    LDAPSSLSocketInfo   *ssoip = NULL;
    LDAPSSLSessionInfo  *sseip;
    PRFileDesc          *sslfd = NULL;


    /*
     * Retrieve session info. so we can store a pointer to our session info.
     * in our socket info. later.
     */
    memset( &sei, 0, sizeof(sei));
    sei.seinfo_size = PRLDAP_SESSIONINFO_SIZE;
    if ( prldap_get_session_info( ld, NULL, &sei ) != LDAP_SUCCESS ) {
        return( -1 );
    }
    sseip = (LDAPSSLSessionInfo *)sei.seinfo_appdata;


    /*
     * Retrieve socket info. so we have the PRFileDesc.
     */
    memset( &soi, 0, sizeof(soi));
    soi.soinfo_size = PRLDAP_SOCKETINFO_SIZE;
    if ( prldap_get_default_socket_info( ld, &soi ) != LDAP_SUCCESS ) {
        return( -1 );
    }

    /*
     * Allocate a structure to hold our socket-specific data.
     */
    if ( NULL == ( ssoip = PR_Calloc( 1, sizeof( LDAPSSLSocketInfo )))) {
        goto reset_socket_and_exit_with_error;
    }
    ssoip->soi_sessioninfo = sseip;

    /*
     * Add SSL layer and let the standard NSPR to LDAP layer and enable SSL.
     */
    if (( sslfd = SSL_ImportFD( NULL, soi.soinfo_prfd )) == NULL ) {
        goto reset_socket_and_exit_with_error;
    }

    if ( SSL_OptionSet( sslfd, SSL_SECURITY, secure ) != SECSuccess ||
                SSL_OptionSet( sslfd, SSL_HANDSHAKE_AS_CLIENT, secure )
                != SECSuccess || ( secure && SSL_ResetHandshake( sslfd,
                PR_FALSE ) != SECSuccess )) {
        goto reset_socket_and_exit_with_error;
    }

    /*
     * Let the standard NSPR to LDAP layer know about the new socket and
     * our own socket-specific data.
     */
    soi.soinfo_prfd = sslfd;
    soi.soinfo_appdata = (void *)ssoip;
    if ( prldap_set_default_socket_info( ld, &soi ) != LDAP_SUCCESS ) {
        goto reset_socket_and_exit_with_error;
    }

    /*
     * Install certificate hook function.
     */
    if ( SSL_AuthCertificateHook( soi.soinfo_prfd,
                                  (SSLAuthCertificate)ldapssl_AuthCertificate,
                                  (void *)CERT_GetDefaultCertDB()) != 0 ) {
        goto reset_socket_and_exit_with_error;
    }

    if ( SSL_GetClientAuthDataHook( soi.soinfo_prfd,
                get_clientauth_data, sseip->lssei_certnickname ? sseip : NULL )
		!= 0 ) {
        goto reset_socket_and_exit_with_error;
    }

    return 0;

 reset_socket_and_exit_with_error:
    if ( NULL != sslfd ) {
        /*
         * "Unimport" the socket from SSL, i.e. get rid of the upper layer of
         * the file descriptor stack, which represents SSL.
         */
        soi.soinfo_prfd = sslfd;
        sslfd = PR_PopIOLayer( soi.soinfo_prfd, PR_TOP_IO_LAYER );
        sslfd->dtor( sslfd );
    }
    if ( NULL != ssoip ) {
        ldapssl_free_socket_info( &ssoip );
        soi.soinfo_appdata = NULL;
    }
    prldap_set_default_socket_info( ld, &soi );

    return( -1 );
}


/*
 * Reset an LDAP session from SSL to a non-secure status.
 * Basically, this function undoes the work done by ldapssl_install_routines.
 */
int ldapssl_reset_to_nonsecure ( LDAP *ld )
{
    PRLDAPSessionInfo   sei;
    LDAPSSLSessionInfo  *sseip;

    struct ldap_x_ext_io_fns    iofns;
    int rc = 0;

    /*
     * Retrieve session info.
     */
    memset( &sei, 0, sizeof(sei));
    sei.seinfo_size = PRLDAP_SESSIONINFO_SIZE;
    if ( prldap_get_session_info( ld, NULL, &sei ) != LDAP_SUCCESS ) {
        return( -1 );
    }
    sseip = (LDAPSSLSessionInfo *)sei.seinfo_appdata;

    if ( sseip != NULL ) {
        /*
         * Reset the standard extended io functions.
         */
        memset( &iofns, 0, sizeof(iofns));
        iofns.lextiof_size = LDAP_X_EXTIO_FNS_SIZE;
        if ( ldap_get_option( ld, LDAP_X_OPT_EXTIO_FN_PTRS, (void *)&iofns )
		< 0) {
            rc = -1;
            goto free_session_info;
        }

        /* reset socket, connect, and ioctl */
        iofns.lextiof_connect = sseip->lssei_std_functions.lssf_connect_fn;
        iofns.lextiof_close = sseip->lssei_std_functions.lssf_close_fn;
        iofns.lextiof_disposehandle =
			sseip->lssei_std_functions.lssf_disposehdl_fn;

        if ( ldap_set_option( ld, LDAP_X_OPT_EXTIO_FN_PTRS, (void *)&iofns )
		< 0) {
            rc = -1;
            goto free_session_info;
        }

free_session_info:
        ldapssl_free_session_info( &sseip );
        sei.seinfo_appdata = NULL;
        if ( prldap_set_session_info( ld, NULL, &sei ) != LDAP_SUCCESS ) {
            rc = -1;
        }
    } /* if ( sseip && *sseip ) */

    if ( ldap_set_option( ld, LDAP_OPT_SSL, LDAP_OPT_OFF ) < 0 ) {
        return (-1);
    }

    return rc;
}


#ifdef _SOLARIS_SDK
static void
_nss_initf_ipnodes(nss_db_params_t *p)
{
	static char *no_service = "";

	p->name = NSS_DBNAM_IPNODES;
        p->flags |= NSS_USE_DEFAULT_CONFIG;
        p->default_config = host_service == NULL ? no_service : host_service;
}

static void
_nss_initf_hosts(nss_db_params_t *p)
{
	static char *no_service = "";

	p->name = NSS_DBNAM_HOSTS;
        p->flags |= NSS_USE_DEFAULT_CONFIG;
        p->default_config = host_service == NULL ? no_service : host_service;
}

static struct hostent *
_switch_gethostbyaddr_r(const char *addr, int len, int type,
	struct hostent *result, char *buffer, int buflen,
	int *h_errnop)
{
        nss_XbyY_args_t arg;
        nss_status_t    res;
	int		(*str2ent)();
	void		(*nss_initf)();
	nss_db_root_t	*nss_db_root;

	if (AF_INET == type) {
		str2ent		= str2hostent;
		nss_initf	= _nss_initf_hosts;
		nss_db_root	= &db_root_hosts;
	} else if (AF_INET6 == type) {
		str2ent		= str2hostent6;
		nss_initf	= _nss_initf_ipnodes;
		nss_db_root	= &db_root_ipnodes;
	} else {
		return NULL;
	}

	NSS_XbyY_INIT(&arg, result, buffer, buflen, str2ent);

        arg.key.hostaddr.addr	= addr;
        arg.key.hostaddr.len	= len;
        arg.key.hostaddr.type	= type;
        arg.stayopen		= 0;

        res = nss_search(nss_db_root, nss_initf,
        	NSS_DBOP_HOSTS_BYADDR, &arg);
        arg.status = res;
        *h_errnop = arg.h_errno;
        return (struct hostent *)NSS_XbyY_FINI(&arg);
}

/*
 * ns_gethostbyaddr is used to be a substitute gethostbyaddr for
 * libldap when ssl will need to determine the fully qualified
 * host name from an address when it is unsafe to use the normal
 * nameservice functions.
 *
 * Note that the ldap name service resolver calls this with the address as
 * a character string - which we must convert into address form.
 */

/*ARGSUSED*/
static LDAPHostEnt *
ns_gethostbyaddr(const char *addr, int len, int type,
	LDAPHostEnt *result, char *buffer, int buflen, int *statusp,
	void *extradata)
{
	LDAPHostEnt	*ldap_hent;
	int		h_errno;
	struct hostent	h_ent;
	struct hostent	*h_e = NULL;
	struct in_addr	a;
	struct in6_addr	a6;
	int		inet_error;	/* error returned by inet_pton */


	if (addr == NULL || result == NULL || buffer == NULL ||
			(type != AF_INET && type != AF_INET6))
		return (NULL);


	(void) memset(&h_ent, 0, sizeof (h_ent));

	if (AF_INET == type) {
		if (inet_pton(type, addr, &a.s_addr) == 1) {
			h_e = _switch_gethostbyaddr_r((char *)&a,
				sizeof (a.s_addr), type, &h_ent,
				buffer, buflen, &h_errno);
		}
	} else if (AF_INET6 == type) {
		if (inet_pton(type, addr, &a6.s6_addr) == 1) {
			h_e = _switch_gethostbyaddr_r((char *)&a6,
				sizeof (a6.s6_addr), type, &h_ent,
				buffer, buflen, &h_errno);
		}
	}

	if (h_e == NULL) {
		ldap_hent = NULL;
	} else {
		(void) memset(result, 0, sizeof (LDAPHostEnt));
		ldap_hent = result;
		result->ldaphe_name = h_e->h_name;
 		result->ldaphe_aliases = h_e->h_aliases;
 		result->ldaphe_addrtype = h_e->h_addrtype;
 		result->ldaphe_length = h_e->h_length;
 		result->ldaphe_addr_list = h_e->h_addr_list;
	}
	return (ldap_hent);
}

/*
 * ldapssl_install_gethostbyaddr attempts to prevent recursion in
 * gethostbyaddr calls when an ip address is given to ssl. This ip address
 * must be resolved to a host name.
 *
 * For example, libsldap cannot use LDAP to resolve this address to a
 * name because of recursion. The caller is instructing libldap to skip
 * the specified name service when resolving addresses for the specified
 * ldap connection.
 *
 * Currently only ldap and dns name services always return fully qualified
 * names. The other name services (files, nis, and nisplus) will returned
 * fully qualified names if the host names are stored as fully qualified names
 * in these name services.
 *
 * Note:
 *
 *	Since host_service applies to all connections, calling
 *	ldapssl_install_gethostbyaddr with different name services to
 *	skip will lead to unpredictable results.
 *
 * Returns:
 *	0	if success
 *	-1	if failure
 */

int
ldapssl_install_gethostbyaddr(LDAP *ld, const char *skip)
{
	enum __nsw_parse_err		pserr;
	struct __nsw_switchconfig	*conf;
	struct __nsw_lookup		*lkp;
	struct ldap_dns_fns		dns_fns;
	char				*name_list = NULL;
	char				*tmp;
	const char			*name;
	int				len;
	boolean_t			got_skip = B_FALSE;

	/*
	 * db_root_hosts.lock mutex is used to ensure that the name list
	 * is not in use by the name service switch while we are updating
	 * the host_service
	 */

	(void) mutex_lock(&db_root_hosts.lock);
	conf = __nsw_getconfig("hosts", &pserr);
	if (conf == NULL) {
		(void) mutex_unlock(&db_root_hosts.lock);
		return (0);
	}

	/* check for ldap and count other backends */
	for (lkp = conf->lookups; lkp != NULL; lkp = lkp->next) {
		name = lkp->service_name;
		if (strcmp(name, skip) == 0) {
			got_skip = B_TRUE;
			continue;
		}
		if (name_list == NULL)
			name_list = strdup(name);
		else {
			len = strlen(name_list);
			tmp = realloc(name_list, len + strlen(name) + 2);
			if (tmp == NULL) {
				free(name_list);
				name_list = NULL;
			} else {
				name_list = tmp;
				name_list[len++] = ' ';
				(void) strcpy(name_list+len, name);
			}
		}
		if (name_list == NULL) {	/* alloc error */
			(void) mutex_unlock(&db_root_hosts.lock);
			__nsw_freeconfig(conf);
			return (-1);
		}
	}
	__nsw_freeconfig(conf);
	if (!got_skip) {
		/*
		 * Since skip name service not used for hosts, we do not need
		 * to install our private address resolution function
		 */
		(void) mutex_unlock(&db_root_hosts.lock);
		if (name_list != NULL)
			free(name_list);
		return (0);
	}
	if (host_service != NULL)
		free(host_service);
	host_service = name_list;
	(void) mutex_unlock(&db_root_hosts.lock);

	if (ldap_get_option(ld, LDAP_OPT_DNS_FN_PTRS, &dns_fns) != 0)
		return (-1);
	dns_fns.lddnsfn_gethostbyaddr = ns_gethostbyaddr;
	if (ldap_set_option(ld, LDAP_OPT_DNS_FN_PTRS, &dns_fns) != 0)
		return (-1);
	return (0);
}
#endif	/* _SOLARIS_SDK */
#endif /* NET_SSL */