Adding upstream version 2.5.13+dfsg.upstream/2.5.13+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1688 insertions, 0 deletions

diff --git a/libraries/libldap/tls_o.c b/libraries/libldap/tls_o.c
new file mode 100644
index 0000000..834d986
--- /dev/null
+++ b/libraries/libldap/tls_o.c
@@ -0,0 +1,1688 @@
+/* tls_o.c - Handle tls/ssl using OpenSSL */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2008-2022 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+/* ACKNOWLEDGEMENTS: Rewritten by Howard Chu
+ */
+
+#include "portable.h"
+
+#ifdef HAVE_OPENSSL
+
+#include "ldap_config.h"
+
+#include <stdio.h>
+
+#include <ac/stdlib.h>
+#include <ac/errno.h>
+#include <ac/socket.h>
+#include <ac/string.h>
+#include <ac/ctype.h>
+#include <ac/time.h>
+#include <ac/unistd.h>
+#include <ac/param.h>
+#include <ac/dirent.h>
+
+#include "ldap-int.h"
+#include "ldap-tls.h"
+
+#ifdef HAVE_OPENSSL_SSL_H
+#include <openssl/ssl.h>
+#include <openssl/x509v3.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+#include <openssl/safestack.h>
+#include <openssl/bn.h>
+#include <openssl/rsa.h>
+#include <openssl/dh.h>
+#endif
+
+#if OPENSSL_VERSION_NUMBER >= 0x10100000
+#define ASN1_STRING_data(x)	ASN1_STRING_get0_data(x)
+#endif
+
+typedef SSL_CTX tlso_ctx;
+typedef SSL tlso_session;
+
+static BIO_METHOD * tlso_bio_method = NULL;
+static BIO_METHOD * tlso_bio_setup( void );
+
+static int  tlso_opt_trace = 1;
+
+static void tlso_report_error( void );
+
+static void tlso_info_cb( const SSL *ssl, int where, int ret );
+static int tlso_verify_cb( int ok, X509_STORE_CTX *ctx );
+static int tlso_verify_ok( int ok, X509_STORE_CTX *ctx );
+static int tlso_seed_PRNG( const char *randfile );
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+/*
+ * OpenSSL 1.1 API and later has new locking code
+*/
+static RSA * tlso_tmp_rsa_cb( SSL *ssl, int is_export, int key_length );
+
+#ifdef LDAP_R_COMPILE
+/*
+ * provide mutexes for the OpenSSL library.
+ */
+static ldap_pvt_thread_mutex_t	tlso_mutexes[CRYPTO_NUM_LOCKS];
+
+static void tlso_locking_cb( int mode, int type, const char *file, int line )
+{
+	if ( mode & CRYPTO_LOCK ) {
+		ldap_pvt_thread_mutex_lock( &tlso_mutexes[type] );
+	} else {
+		ldap_pvt_thread_mutex_unlock( &tlso_mutexes[type] );
+	}
+}
+
+#if OPENSSL_VERSION_NUMBER >= 0x0909000
+static void tlso_thread_self( CRYPTO_THREADID *id )
+{
+	CRYPTO_THREADID_set_pointer( id, (void *)ldap_pvt_thread_self() );
+}
+#define CRYPTO_set_id_callback(foo)	CRYPTO_THREADID_set_callback(foo)
+#else
+static unsigned long tlso_thread_self( void )
+{
+	/* FIXME: CRYPTO_set_id_callback only works when ldap_pvt_thread_t
+	 * is an integral type that fits in an unsigned long
+	 */
+
+	/* force an error if the ldap_pvt_thread_t type is too large */
+	enum { ok = sizeof( ldap_pvt_thread_t ) <= sizeof( unsigned long ) };
+	typedef struct { int dummy: ok ? 1 : -1; } Check[ok ? 1 : -1];
+
+	return (unsigned long) ldap_pvt_thread_self();
+}
+#endif
+
+static void tlso_thr_init( void )
+{
+	int i;
+
+	for( i=0; i< CRYPTO_NUM_LOCKS ; i++ ) {
+		ldap_pvt_thread_mutex_init( &tlso_mutexes[i] );
+	}
+	CRYPTO_set_locking_callback( tlso_locking_cb );
+	CRYPTO_set_id_callback( tlso_thread_self );
+}
+#endif /* LDAP_R_COMPILE */
+#else
+#ifdef LDAP_R_COMPILE
+static void tlso_thr_init( void ) {}
+#endif
+#endif /* OpenSSL 1.1 */
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+/*
+ * OpenSSL 1.1 API and later makes the BIO method concrete types internal.
+ */
+
+static BIO_METHOD *
+BIO_meth_new( int type, const char *name )
+{
+	BIO_METHOD *method = LDAP_MALLOC( sizeof(BIO_METHOD) );
+	memset( method, 0, sizeof(BIO_METHOD) );
+
+	method->type = type;
+	method->name = name;
+
+	return method;
+}
+
+static void
+BIO_meth_free( BIO_METHOD *meth )
+{
+	if ( meth == NULL ) {
+		return;
+	}
+
+	LDAP_FREE( meth );
+}
+
+#define BIO_meth_set_write(m, f) (m)->bwrite = (f)
+#define BIO_meth_set_read(m, f) (m)->bread = (f)
+#define BIO_meth_set_puts(m, f) (m)->bputs = (f)
+#define BIO_meth_set_gets(m, f) (m)->bgets = (f)
+#define BIO_meth_set_ctrl(m, f) (m)->ctrl = (f)
+#define BIO_meth_set_create(m, f) (m)->create = (f)
+#define BIO_meth_set_destroy(m, f) (m)->destroy = (f)
+
+#endif /* OpenSSL 1.1 */
+
+static STACK_OF(X509_NAME) *
+tlso_ca_list( char * bundle, char * dir, X509 *cert )
+{
+	STACK_OF(X509_NAME) *ca_list = NULL;
+
+	if ( bundle ) {
+		ca_list = SSL_load_client_CA_file( bundle );
+	}
+#if defined(HAVE_DIRENT_H) || defined(dirent)
+	if ( dir ) {
+		int freeit = 0;
+
+		if ( !ca_list ) {
+			ca_list = sk_X509_NAME_new_null();
+			freeit = 1;
+		}
+		if ( !SSL_add_dir_cert_subjects_to_stack( ca_list, dir ) &&
+			freeit ) {
+			sk_X509_NAME_free( ca_list );
+			ca_list = NULL;
+		}
+	}
+#endif
+	if ( cert ) {
+		X509_NAME *xn = X509_get_subject_name( cert );
+		xn = X509_NAME_dup( xn );
+		if ( !ca_list )
+			ca_list = sk_X509_NAME_new_null();
+		if ( xn && ca_list )
+			sk_X509_NAME_push( ca_list, xn );
+	}
+	return ca_list;
+}
+
+/*
+ * Initialize TLS subsystem. Should be called only once.
+ */
+static int
+tlso_init( void )
+{
+	struct ldapoptions *lo = LDAP_INT_GLOBAL_OPT();   
+#ifdef HAVE_EBCDIC
+	{
+		char *file = LDAP_STRDUP( lo->ldo_tls_randfile );
+		if ( file ) __atoe( file );
+		(void) tlso_seed_PRNG( file );
+		LDAP_FREE( file );
+	}
+#else
+	(void) tlso_seed_PRNG( lo->ldo_tls_randfile );
+#endif
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+	SSL_load_error_strings();
+	SSL_library_init();
+	OpenSSL_add_all_digests();
+#else
+	OPENSSL_init_ssl(0, NULL);
+#endif
+
+	/* FIXME: mod_ssl does this */
+	X509V3_add_standard_extensions();
+
+	tlso_bio_method = tlso_bio_setup();
+
+	return 0;
+}
+
+/*
+ * Tear down the TLS subsystem. Should only be called once.
+ */
+static void
+tlso_destroy( void )
+{
+	struct ldapoptions *lo = LDAP_INT_GLOBAL_OPT();   
+
+	BIO_meth_free( tlso_bio_method );
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+	EVP_cleanup();
+	ERR_remove_thread_state(NULL);
+	ERR_free_strings();
+#endif
+
+	if ( lo->ldo_tls_randfile ) {
+		LDAP_FREE( lo->ldo_tls_randfile );
+		lo->ldo_tls_randfile = NULL;
+	}
+}
+
+static tls_ctx *
+tlso_ctx_new( struct ldapoptions *lo )
+{
+	return (tls_ctx *) SSL_CTX_new( SSLv23_method() );
+}
+
+static void
+tlso_ctx_ref( tls_ctx *ctx )
+{
+	tlso_ctx *c = (tlso_ctx *)ctx;
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+#define	SSL_CTX_up_ref(ctx)	CRYPTO_add( &(ctx->references), 1, CRYPTO_LOCK_SSL_CTX )
+#endif
+	SSL_CTX_up_ref( c );
+}
+
+static void
+tlso_ctx_free ( tls_ctx *ctx )
+{
+	tlso_ctx *c = (tlso_ctx *)ctx;
+	SSL_CTX_free( c );
+}
+
+#if OPENSSL_VERSION_NUMBER >= 0x10101000
+static char *
+tlso_stecpy( char *dst, const char *src, const char *end )
+{
+	while ( dst < end && *src )
+		*dst++ = *src++;
+	if ( dst < end )
+		*dst = '\0';
+	return dst;
+}
+
+/* OpenSSL 1.1.1 uses a separate API for TLS1.3 ciphersuites.
+ * Try to find any TLS1.3 ciphers in the given list of suites.
+ */
+static void
+tlso_ctx_cipher13( tlso_ctx *ctx, char *suites )
+{
+	char tls13_suites[1024], *ts = tls13_suites, *te = tls13_suites + sizeof(tls13_suites);
+	char *ptr, *colon, *nptr;
+	char sname[128];
+	STACK_OF(SSL_CIPHER) *cs;
+	SSL *s = SSL_new( ctx );
+	int ret;
+
+	if ( !s )
+		return;
+
+	*ts = '\0';
+
+	/* check individual suites in a separate SSL handle before
+	 * mucking with the provided ctx. Init it to a known
+	 * mostly-empty state.
+	 */
+	SSL_set_ciphersuites( s, "" );
+	SSL_set_cipher_list( s, SSL3_TXT_RSA_NULL_SHA );
+
+	for ( ptr = suites;; ) {
+		colon = strchr( ptr, ':' );
+		if ( colon ) {
+			int len = colon - ptr;
+			if ( len > 63 ) len = 63;
+			strncpy( sname, ptr, len );
+			sname[len] = '\0';
+			nptr = sname;
+		} else {
+			nptr = ptr;
+		}
+		if ( SSL_set_ciphersuites( s, nptr )) {
+			cs = SSL_get_ciphers( s );
+			if ( cs ) {
+				const char *ver = SSL_CIPHER_get_version( sk_SSL_CIPHER_value( cs, 0 ));
+				if ( !strncmp( ver, "TLSv", 4 ) && strncmp( ver+4, "1.3", 3 ) >= 0 ) {
+					if ( tls13_suites[0] )
+						ts = tlso_stecpy( ts, ":", te );
+					ts = tlso_stecpy( ts, sname, te );
+				}
+			}
+		}
+		if ( !colon || ts >= te )
+			break;
+		ptr = colon+1;
+	}
+	SSL_free( s );
+
+	/* If no TLS1.3 ciphersuites were specified, leave current settings untouched. */
+	if ( tls13_suites[0] )
+		SSL_CTX_set_ciphersuites( ctx, tls13_suites );
+}
+#endif /* OpenSSL 1.1.1 */
+
+/*
+ * initialize a new TLS context
+ */
+static int
+tlso_ctx_init( struct ldapoptions *lo, struct ldaptls *lt, int is_server )
+{
+	tlso_ctx *ctx = (tlso_ctx *)lo->ldo_tls_ctx;
+	int i;
+
+	if ( is_server ) {
+		SSL_CTX_set_session_id_context( ctx,
+			(const unsigned char *) "OpenLDAP", sizeof("OpenLDAP")-1 );
+	}
+
+	if ( lo->ldo_tls_protocol_min ) {
+		int opt = 0;
+		if ( lo->ldo_tls_protocol_min > LDAP_OPT_X_TLS_PROTOCOL_SSL2 ) {
+			opt |= SSL_OP_NO_SSLv2;
+			SSL_CTX_clear_options( ctx, SSL_OP_NO_SSLv3 );
+		}
+		if ( lo->ldo_tls_protocol_min > LDAP_OPT_X_TLS_PROTOCOL_SSL3 )
+			opt |= SSL_OP_NO_SSLv3;
+#ifdef SSL_OP_NO_TLSv1
+		if ( lo->ldo_tls_protocol_min > LDAP_OPT_X_TLS_PROTOCOL_TLS1_0 )
+			opt |= SSL_OP_NO_TLSv1;
+#endif
+#ifdef SSL_OP_NO_TLSv1_1
+		if ( lo->ldo_tls_protocol_min > LDAP_OPT_X_TLS_PROTOCOL_TLS1_1 )
+			opt |= SSL_OP_NO_TLSv1_1;
+#endif
+#ifdef SSL_OP_NO_TLSv1_2
+		if ( lo->ldo_tls_protocol_min > LDAP_OPT_X_TLS_PROTOCOL_TLS1_2 )
+			opt |= SSL_OP_NO_TLSv1_2;
+#endif
+#ifdef SSL_OP_NO_TLSv1_3
+		if ( lo->ldo_tls_protocol_min > LDAP_OPT_X_TLS_PROTOCOL_TLS1_3 )
+			opt |= SSL_OP_NO_TLSv1_3;
+#endif
+		if ( opt )
+			SSL_CTX_set_options( ctx, opt );
+	}
+	if ( lo->ldo_tls_protocol_max ) {
+		int opt = 0;
+#ifdef SSL_OP_NO_TLSv1_3
+		if ( lo->ldo_tls_protocol_max < LDAP_OPT_X_TLS_PROTOCOL_TLS1_3 )
+			opt |= SSL_OP_NO_TLSv1_3;
+#endif
+#ifdef SSL_OP_NO_TLSv1_2
+		if ( lo->ldo_tls_protocol_max < LDAP_OPT_X_TLS_PROTOCOL_TLS1_2 )
+			opt |= SSL_OP_NO_TLSv1_2;
+#endif
+#ifdef SSL_OP_NO_TLSv1_1
+		if ( lo->ldo_tls_protocol_max < LDAP_OPT_X_TLS_PROTOCOL_TLS1_1 )
+			opt |= SSL_OP_NO_TLSv1_1;
+#endif
+#ifdef SSL_OP_NO_TLSv1
+		if ( lo->ldo_tls_protocol_max < LDAP_OPT_X_TLS_PROTOCOL_TLS1_0 )
+			opt |= SSL_OP_NO_TLSv1;
+#endif
+		if ( lo->ldo_tls_protocol_max < LDAP_OPT_X_TLS_PROTOCOL_SSL3 )
+			opt |= SSL_OP_NO_SSLv3;
+		if ( opt )
+			SSL_CTX_set_options( ctx, opt );
+	}
+
+	if ( lo->ldo_tls_ciphersuite ) {
+#if OPENSSL_VERSION_NUMBER >= 0x10101000
+		tlso_ctx_cipher13( ctx, lt->lt_ciphersuite );
+#endif
+		if ( !SSL_CTX_set_cipher_list( ctx, lt->lt_ciphersuite ) )
+		{
+			Debug1( LDAP_DEBUG_ANY,
+				   "TLS: could not set cipher list %s.\n",
+				   lo->ldo_tls_ciphersuite );
+			tlso_report_error();
+			return -1;
+		}
+	}
+
+	if ( lo->ldo_tls_cacertfile == NULL && lo->ldo_tls_cacertdir == NULL &&
+		lo->ldo_tls_cacert.bv_val == NULL ) {
+		if ( !SSL_CTX_set_default_verify_paths( ctx ) ) {
+			Debug0( LDAP_DEBUG_ANY, "TLS: "
+				"could not use default certificate paths" );
+			tlso_report_error();
+			return -1;
+		}
+	} else {
+		X509 *cert = NULL;
+		if ( lo->ldo_tls_cacert.bv_val ) {
+			const unsigned char *pp = (const unsigned char *) (lo->ldo_tls_cacert.bv_val);
+			cert = d2i_X509( NULL, &pp, lo->ldo_tls_cacert.bv_len );
+			X509_STORE *store = SSL_CTX_get_cert_store( ctx );
+			if ( !X509_STORE_add_cert( store, cert )) {
+				Debug0( LDAP_DEBUG_ANY, "TLS: "
+					"could not use CA certificate" );
+				tlso_report_error();
+				return -1;
+			}
+		}
+		if (( lt->lt_cacertfile || lt->lt_cacertdir ) && !SSL_CTX_load_verify_locations( ctx,
+				lt->lt_cacertfile, lt->lt_cacertdir ) )
+		{
+			Debug2( LDAP_DEBUG_ANY, "TLS: "
+				"could not load verify locations (file:`%s',dir:`%s').\n",
+				lo->ldo_tls_cacertfile ? lo->ldo_tls_cacertfile : "",
+				lo->ldo_tls_cacertdir ? lo->ldo_tls_cacertdir : "" );
+			tlso_report_error();
+			return -1;
+		}
+
+		if ( is_server ) {
+			STACK_OF(X509_NAME) *calist;
+			/* List of CA names to send to a client */
+			calist = tlso_ca_list( lt->lt_cacertfile, lt->lt_cacertdir, cert );
+			if ( !calist ) {
+				Debug2( LDAP_DEBUG_ANY, "TLS: "
+					"could not load client CA list (file:`%s',dir:`%s').\n",
+					lo->ldo_tls_cacertfile ? lo->ldo_tls_cacertfile : "",
+					lo->ldo_tls_cacertdir ? lo->ldo_tls_cacertdir : "" );
+				tlso_report_error();
+				return -1;
+			}
+
+			SSL_CTX_set_client_CA_list( ctx, calist );
+		}
+		if ( cert )
+			X509_free( cert );
+	}
+
+	if ( lo->ldo_tls_cert.bv_val )
+	{
+		const unsigned char *pp = (const unsigned char *) (lo->ldo_tls_cert.bv_val);
+		X509 *cert = d2i_X509( NULL, &pp, lo->ldo_tls_cert.bv_len );
+		if ( !SSL_CTX_use_certificate( ctx, cert )) {
+			Debug0( LDAP_DEBUG_ANY,
+				"TLS: could not use certificate.\n" );
+			tlso_report_error();
+			return -1;
+		}
+		X509_free( cert );
+	} else
+	if ( lo->ldo_tls_certfile &&
+		!SSL_CTX_use_certificate_chain_file( ctx, lt->lt_certfile) )
+	{
+		Debug1( LDAP_DEBUG_ANY,
+			"TLS: could not use certificate file `%s'.\n",
+			lo->ldo_tls_certfile );
+		tlso_report_error();
+		return -1;
+	}
+
+	/* Key validity is checked automatically if cert has already been set */
+	if ( lo->ldo_tls_key.bv_val )
+	{
+		const unsigned char *pp = (const unsigned char *) (lo->ldo_tls_key.bv_val);
+		EVP_PKEY *pkey = d2i_AutoPrivateKey( NULL, &pp, lo->ldo_tls_key.bv_len );
+		if ( !SSL_CTX_use_PrivateKey( ctx, pkey ))
+		{
+			Debug0( LDAP_DEBUG_ANY,
+				"TLS: could not use private key.\n" );
+			tlso_report_error();
+			return -1;
+		}
+		EVP_PKEY_free( pkey );
+	} else
+	if ( lo->ldo_tls_keyfile &&
+		!SSL_CTX_use_PrivateKey_file( ctx,
+			lt->lt_keyfile, SSL_FILETYPE_PEM ) )
+	{
+		Debug1( LDAP_DEBUG_ANY,
+			"TLS: could not use key file `%s'.\n",
+			lo->ldo_tls_keyfile );
+		tlso_report_error();
+		return -1;
+	}
+
+	if ( is_server && lo->ldo_tls_dhfile ) {
+		DH *dh;
+		BIO *bio;
+
+		if (( bio=BIO_new_file( lt->lt_dhfile,"r" )) == NULL ) {
+			Debug1( LDAP_DEBUG_ANY,
+				"TLS: could not use DH parameters file `%s'.\n",
+				lo->ldo_tls_dhfile );
+			tlso_report_error();
+			return -1;
+		}
+		if (!( dh=PEM_read_bio_DHparams( bio, NULL, NULL, NULL ))) {
+			Debug1( LDAP_DEBUG_ANY,
+				"TLS: could not read DH parameters file `%s'.\n",
+				lo->ldo_tls_dhfile );
+			tlso_report_error();
+			BIO_free( bio );
+			return -1;
+		}
+		BIO_free( bio );
+		SSL_CTX_set_tmp_dh( ctx, dh );
+		SSL_CTX_set_options( ctx, SSL_OP_SINGLE_DH_USE );
+		DH_free( dh );
+	}
+
+	if ( lo->ldo_tls_ecname ) {
+#ifdef OPENSSL_NO_EC
+		Debug0( LDAP_DEBUG_ANY,
+			"TLS: Elliptic Curves not supported.\n" );
+		return -1;
+#else
+		if ( !SSL_CTX_set1_curves_list( ctx, lt->lt_ecname )) {
+			Debug1( LDAP_DEBUG_ANY,
+				"TLS: could not set EC name `%s'.\n",
+				lo->ldo_tls_ecname );
+			tlso_report_error();
+			return -1;
+		}
+	/*
+	 * This is a NOP in OpenSSL 1.1.0 and later, where curves are always
+	 * auto-negotiated.
+	 */
+#if OPENSSL_VERSION_NUMBER < 0x10100000UL
+		if ( SSL_CTX_set_ecdh_auto( ctx, 1 ) <= 0 ) {
+			Debug0( LDAP_DEBUG_ANY,
+				"TLS: could not enable automatic EC negotiation.\n" );
+		}
+#endif
+#endif	/* OPENSSL_NO_EC */
+	}
+
+	if ( tlso_opt_trace ) {
+		SSL_CTX_set_info_callback( ctx, tlso_info_cb );
+	}
+
+	i = SSL_VERIFY_NONE;
+	if ( lo->ldo_tls_require_cert ) {
+		i = SSL_VERIFY_PEER;
+		if ( lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_DEMAND ||
+			 lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_HARD ) {
+			i |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
+		}
+	}
+
+	SSL_CTX_set_verify( ctx, i,
+		lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_ALLOW ?
+		tlso_verify_ok : tlso_verify_cb );
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+	SSL_CTX_set_tmp_rsa_callback( ctx, tlso_tmp_rsa_cb );
+#endif
+	if ( lo->ldo_tls_crlcheck ) {
+		X509_STORE *x509_s = SSL_CTX_get_cert_store( ctx );
+		if ( lo->ldo_tls_crlcheck == LDAP_OPT_X_TLS_CRL_PEER ) {
+			X509_STORE_set_flags( x509_s, X509_V_FLAG_CRL_CHECK );
+		} else if ( lo->ldo_tls_crlcheck == LDAP_OPT_X_TLS_CRL_ALL ) {
+			X509_STORE_set_flags( x509_s, 
+					X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL  );
+		}
+	}
+	/* Explicitly honor the server side cipher suite preference */
+	SSL_CTX_set_options( ctx, SSL_OP_CIPHER_SERVER_PREFERENCE );
+	return 0;
+}
+
+static tls_session *
+tlso_session_new( tls_ctx *ctx, int is_server )
+{
+	tlso_ctx *c = (tlso_ctx *)ctx;
+	return (tls_session *)SSL_new( c );
+}
+
+static int
+tlso_session_connect( LDAP *ld, tls_session *sess, const char *name_in )
+{
+	tlso_session *s = (tlso_session *)sess;
+	int rc;
+
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+	if ( name_in ) {
+		rc = SSL_set_tlsext_host_name( s, name_in );
+		if ( !rc )		/* can fail to strdup the name */
+			return -1;
+	}
+#endif
+	/* Caller expects 0 = success, OpenSSL returns 1 = success */
+	rc = SSL_connect( s ) - 1;
+	return rc;
+}
+
+static int
+tlso_session_accept( tls_session *sess )
+{
+	tlso_session *s = (tlso_session *)sess;
+
+	/* Caller expects 0 = success, OpenSSL returns 1 = success */
+	return SSL_accept( s ) - 1;
+}
+
+static int
+tlso_session_upflags( Sockbuf *sb, tls_session *sess, int rc )
+{
+	tlso_session *s = (tlso_session *)sess;
+
+	/* 1 was subtracted above, offset it back now */
+	rc = SSL_get_error(s, rc+1);
+	if (rc == SSL_ERROR_WANT_READ) {
+		sb->sb_trans_needs_read  = 1;
+		return 1;
+
+	} else if (rc == SSL_ERROR_WANT_WRITE) {
+		sb->sb_trans_needs_write = 1;
+		return 1;
+
+	} else if (rc == SSL_ERROR_WANT_CONNECT) {
+		return 1;
+	}
+	return 0;
+}
+
+static char *
+tlso_session_errmsg( tls_session *sess, int rc, char *buf, size_t len )
+{
+	char err[256] = "";
+	const char *certerr=NULL;
+	tlso_session *s = (tlso_session *)sess;
+
+	rc = ERR_peek_error();
+	if ( rc ) {
+		ERR_error_string_n( rc, err, sizeof(err) );
+		if ( ( ERR_GET_LIB(rc) == ERR_LIB_SSL ) && 
+				( ERR_GET_REASON(rc) == SSL_R_CERTIFICATE_VERIFY_FAILED ) ) {
+			int certrc = SSL_get_verify_result(s);
+			certerr = (char *)X509_verify_cert_error_string(certrc);
+		}
+		snprintf(buf, len, "%s%s%s%s", err, certerr ? " (" :"", 
+				certerr ? certerr : "", certerr ?  ")" : "" );
+		return buf;
+	}
+	return NULL;
+}
+
+static int
+tlso_session_my_dn( tls_session *sess, struct berval *der_dn )
+{
+	tlso_session *s = (tlso_session *)sess;
+	X509 *x;
+	X509_NAME *xn;
+
+	x = SSL_get_certificate( s );
+
+	if (!x) return LDAP_INVALID_CREDENTIALS;
+	
+	xn = X509_get_subject_name(x);
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+	der_dn->bv_len = i2d_X509_NAME( xn, NULL );
+	der_dn->bv_val = xn->bytes->data;
+#else
+	{
+		size_t len = 0;
+		der_dn->bv_val = NULL;
+		X509_NAME_get0_der( xn, (const unsigned char **)&der_dn->bv_val, &len );
+		der_dn->bv_len = len;
+	}
+#endif
+	/* Don't X509_free, the session is still using it */
+	return 0;
+}
+
+static X509 *
+tlso_get_cert( SSL *s )
+{
+	/* If peer cert was bad, treat as if no cert was given */
+	if (SSL_get_verify_result(s)) {
+		return NULL;
+	}
+	return SSL_get_peer_certificate(s);
+}
+
+static int
+tlso_session_peer_dn( tls_session *sess, struct berval *der_dn )
+{
+	tlso_session *s = (tlso_session *)sess;
+	X509 *x = tlso_get_cert( s );
+	X509_NAME *xn;
+
+	if ( !x )
+		return LDAP_INVALID_CREDENTIALS;
+
+	xn = X509_get_subject_name(x);
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+	der_dn->bv_len = i2d_X509_NAME( xn, NULL );
+	der_dn->bv_val = xn->bytes->data;
+#else
+	{
+		size_t len = 0;
+		der_dn->bv_val = NULL;
+		X509_NAME_get0_der( xn, (const unsigned char **)&der_dn->bv_val, &len );
+		der_dn->bv_len = len;
+	}
+#endif
+	X509_free(x);
+	return 0;
+}
+
+/* what kind of hostname were we given? */
+#define	IS_DNS	0
+#define	IS_IP4	1
+#define	IS_IP6	2
+
+static int
+tlso_session_chkhost( LDAP *ld, tls_session *sess, const char *name_in )
+{
+	tlso_session *s = (tlso_session *)sess;
+	int i, ret = LDAP_LOCAL_ERROR;
+	int chkSAN = ld->ld_options.ldo_tls_require_san, gotSAN = 0;
+	X509 *x;
+	const char *name;
+	char *ptr;
+	int ntype = IS_DNS, nlen;
+#ifdef LDAP_PF_INET6
+	struct in6_addr addr;
+#else
+	struct in_addr addr;
+#endif
+
+	if( ldap_int_hostname &&
+		( !name_in || !strcasecmp( name_in, "localhost" ) ) )
+	{
+		name = ldap_int_hostname;
+	} else {
+		name = name_in;
+	}
+	nlen = strlen(name);
+
+	x = tlso_get_cert(s);
+	if (!x) {
+		Debug0( LDAP_DEBUG_ANY,
+			"TLS: unable to get peer certificate.\n" );
+		/* If this was a fatal condition, things would have
+		 * aborted long before now.
+		 */
+		return LDAP_SUCCESS;
+	}
+
+#ifdef LDAP_PF_INET6
+	if (inet_pton(AF_INET6, name, &addr)) {
+		ntype = IS_IP6;
+	} else 
+#endif
+	if ((ptr = strrchr(name, '.')) && isdigit((unsigned char)ptr[1])) {
+		if (inet_aton(name, (struct in_addr *)&addr)) ntype = IS_IP4;
+	}
+
+	if (chkSAN) {
+	i = X509_get_ext_by_NID(x, NID_subject_alt_name, -1);
+	if (i >= 0) {
+		X509_EXTENSION *ex;
+		STACK_OF(GENERAL_NAME) *alt;
+
+		ex = X509_get_ext(x, i);
+		alt = X509V3_EXT_d2i(ex);
+		if (alt) {
+			int n, len2 = 0;
+			char *domain = NULL;
+			GENERAL_NAME *gn;
+
+			gotSAN = 1;
+			if (ntype == IS_DNS) {
+				domain = strchr(name, '.');
+				if (domain) {
+					len2 = nlen - (domain-name);
+				}
+			}
+			n = sk_GENERAL_NAME_num(alt);
+			for (i=0; i<n; i++) {
+				char *sn;
+				int sl;
+				gn = sk_GENERAL_NAME_value(alt, i);
+				if (gn->type == GEN_DNS) {
+					if (ntype != IS_DNS) continue;
+
+					sn = (char *) ASN1_STRING_data(gn->d.ia5);
+					sl = ASN1_STRING_length(gn->d.ia5);
+
+					/* ignore empty */
+					if (sl == 0) continue;
+
+					/* Is this an exact match? */
+					if ((nlen == sl) && !strncasecmp(name, sn, nlen)) {
+						break;
+					}
+
+					/* Is this a wildcard match? */
+					if (domain && (sn[0] == '*') && (sn[1] == '.') &&
+						(len2 == sl-1) && !strncasecmp(domain, &sn[1], len2))
+					{
+						break;
+					}
+
+				} else if (gn->type == GEN_IPADD) {
+					if (ntype == IS_DNS) continue;
+
+					sn = (char *) ASN1_STRING_data(gn->d.ia5);
+					sl = ASN1_STRING_length(gn->d.ia5);
+
+#ifdef LDAP_PF_INET6
+					if (ntype == IS_IP6 && sl != sizeof(struct in6_addr)) {
+						continue;
+					} else
+#endif
+					if (ntype == IS_IP4 && sl != sizeof(struct in_addr)) {
+						continue;
+					}
+					if (!memcmp(sn, &addr, sl)) {
+						break;
+					}
+				}
+			}
+
+			GENERAL_NAMES_free(alt);
+			if (i < n) {	/* Found a match */
+				ret = LDAP_SUCCESS;
+			}
+		}
+	}
+	}
+	if (ret != LDAP_SUCCESS && chkSAN) {
+		switch(chkSAN) {
+		case LDAP_OPT_X_TLS_DEMAND:
+		case LDAP_OPT_X_TLS_HARD:
+			if (!gotSAN) {
+				Debug0( LDAP_DEBUG_ANY,
+					"TLS: unable to get subjectAltName from peer certificate.\n" );
+				ret = LDAP_CONNECT_ERROR;
+				if ( ld->ld_error ) {
+					LDAP_FREE( ld->ld_error );
+				}
+				ld->ld_error = LDAP_STRDUP(
+					_("TLS: unable to get subjectAltName from peer certificate"));
+				goto done;
+			}
+			/* FALLTHRU */
+		case LDAP_OPT_X_TLS_TRY:
+			if (gotSAN) {
+				Debug1( LDAP_DEBUG_ANY, "TLS: hostname (%s) does not match "
+					"subjectAltName in certificate.\n",
+					name );
+				ret = LDAP_CONNECT_ERROR;
+				if ( ld->ld_error ) {
+					LDAP_FREE( ld->ld_error );
+				}
+				ld->ld_error = LDAP_STRDUP(
+					_("TLS: hostname does not match subjectAltName in peer certificate"));
+				goto done;
+			}
+			break;
+		case LDAP_OPT_X_TLS_ALLOW:
+			break;
+		}
+	}
+
+	if (ret != LDAP_SUCCESS) {
+		X509_NAME *xn;
+		X509_NAME_ENTRY *ne;
+		ASN1_OBJECT *obj;
+		ASN1_STRING *cn = NULL;
+		int navas;
+
+		/* find the last CN */
+		obj = OBJ_nid2obj( NID_commonName );
+		if ( !obj ) goto no_cn;	/* should never happen */
+
+		xn = X509_get_subject_name(x);
+		navas = X509_NAME_entry_count( xn );
+		for ( i=navas-1; i>=0; i-- ) {
+			ne = X509_NAME_get_entry( xn, i );
+			if ( !OBJ_cmp( X509_NAME_ENTRY_get_object(ne), obj )) {
+				cn = X509_NAME_ENTRY_get_data( ne );
+				break;
+			}
+		}
+
+		if( !cn )
+		{
+no_cn:
+			Debug0( LDAP_DEBUG_ANY,
+				"TLS: unable to get common name from peer certificate.\n" );
+			ret = LDAP_CONNECT_ERROR;
+			if ( ld->ld_error ) {
+				LDAP_FREE( ld->ld_error );
+			}
+			ld->ld_error = LDAP_STRDUP(
+				_("TLS: unable to get CN from peer certificate"));
+
+		} else if ( cn->length == nlen &&
+			strncasecmp( name, (char *) cn->data, nlen ) == 0 ) {
+			ret = LDAP_SUCCESS;
+
+		} else if (( cn->data[0] == '*' ) && ( cn->data[1] == '.' )) {
+			char *domain = strchr(name, '.');
+			if( domain ) {
+				int dlen;
+
+				dlen = nlen - (domain-name);
+
+				/* Is this a wildcard match? */
+				if ((dlen == cn->length-1) &&
+					!strncasecmp(domain, (char *) &cn->data[1], dlen)) {
+					ret = LDAP_SUCCESS;
+				}
+			}
+		}
+
+		if( ret == LDAP_LOCAL_ERROR ) {
+			Debug3( LDAP_DEBUG_ANY, "TLS: hostname (%s) does not match "
+				"common name in certificate (%.*s).\n", 
+				name, cn->length, cn->data );
+			ret = LDAP_CONNECT_ERROR;
+			if ( ld->ld_error ) {
+				LDAP_FREE( ld->ld_error );
+			}
+			ld->ld_error = LDAP_STRDUP(
+				_("TLS: hostname does not match name in peer certificate"));
+		}
+	}
+done:
+	X509_free(x);
+	return ret;
+}
+
+static int
+tlso_session_strength( tls_session *sess )
+{
+	tlso_session *s = (tlso_session *)sess;
+
+	return SSL_CIPHER_get_bits(SSL_get_current_cipher(s), NULL);
+}
+
+static int
+tlso_session_unique( tls_session *sess, struct berval *buf, int is_server)
+{
+	tlso_session *s = (tlso_session *)sess;
+
+	/* Usually the client sends the finished msg. But if the
+	 * session was resumed, the server sent the msg.
+	 */
+	if (SSL_session_reused(s) ^ !is_server)
+		buf->bv_len = SSL_get_finished(s, buf->bv_val, buf->bv_len);
+	else
+		buf->bv_len = SSL_get_peer_finished(s, buf->bv_val, buf->bv_len);
+	return buf->bv_len;
+}
+
+static int
+tlso_session_endpoint( tls_session *sess, struct berval *buf, int is_server )
+{
+	tlso_session *s = (tlso_session *)sess;
+	const EVP_MD *md;
+	unsigned int md_len;
+	X509 *cert;
+
+	if ( buf->bv_len < EVP_MAX_MD_SIZE )
+		return 0;
+
+	if ( is_server )
+		cert = SSL_get_certificate( s );
+	else
+		cert = SSL_get_peer_certificate( s );
+
+	if ( cert == NULL )
+		return 0;
+
+#if OPENSSL_VERSION_NUMBER >= 0x10100000
+	md = EVP_get_digestbynid( X509_get_signature_nid( cert ));
+#else
+	md = EVP_get_digestbynid(OBJ_obj2nid( cert->sig_alg->algorithm ));
+#endif
+
+	/* See RFC 5929 */
+	if ( md == NULL ||
+	     md == EVP_md_null() ||
+#ifndef OPENSSL_NO_MD2
+	     md == EVP_md2() ||
+#endif
+#ifndef OPENSSL_NO_MD4
+	     md == EVP_md4() ||
+#endif
+#ifndef OPENSSL_NO_MD5
+	     md == EVP_md5() ||
+#endif
+	     md == EVP_sha1() )
+		md = EVP_sha256();
+
+	if ( !X509_digest( cert, md, (unsigned char *) (buf->bv_val), &md_len ))
+		md_len = 0;
+
+	buf->bv_len = md_len;
+	if ( !is_server )
+		X509_free( cert );
+
+	return md_len;
+}
+
+static const char *
+tlso_session_version( tls_session *sess )
+{
+	tlso_session *s = (tlso_session *)sess;
+	return SSL_get_version(s);
+}
+
+static const char *
+tlso_session_cipher( tls_session *sess )
+{
+	tlso_session *s = (tlso_session *)sess;
+	return SSL_CIPHER_get_name(SSL_get_current_cipher(s));
+}
+
+static int
+tlso_session_peercert( tls_session *sess, struct berval *der )
+{
+	tlso_session *s = (tlso_session *)sess;
+	int ret = -1;
+	X509 *x = SSL_get_peer_certificate(s);
+	if ( x ) {
+		der->bv_len = i2d_X509(x, NULL);
+		der->bv_val = LDAP_MALLOC(der->bv_len);
+		if ( der->bv_val ) {
+			unsigned char *ptr = (unsigned char *) (der->bv_val);
+			i2d_X509(x, &ptr);
+			ret = 0;
+		}
+		X509_free( x );
+	}
+	return ret;
+}
+
+static int
+tlso_session_pinning( LDAP *ld, tls_session *sess, char *hashalg, struct berval *hash )
+{
+	tlso_session *s = (tlso_session *)sess;
+	unsigned char *tmp, digest[EVP_MAX_MD_SIZE];
+	struct berval key,
+				  keyhash = { sizeof(digest), (char *) digest };
+	X509 *cert = SSL_get_peer_certificate(s);
+	int len, rc = LDAP_SUCCESS;
+
+	if ( !cert )
+		return -1;
+
+	len = i2d_X509_PUBKEY( X509_get_X509_PUBKEY(cert), NULL );
+
+	tmp = LDAP_MALLOC( len );
+	key.bv_val = (char *) tmp;
+
+	if ( !key.bv_val ) {
+		rc = -1;
+		goto done;
+	}
+
+	key.bv_len = i2d_X509_PUBKEY( X509_get_X509_PUBKEY(cert), &tmp );
+
+	if ( hashalg ) {
+		const EVP_MD *md;
+		EVP_MD_CTX *mdctx;
+		unsigned int len = keyhash.bv_len;
+
+		md = EVP_get_digestbyname( hashalg );
+		if ( !md ) {
+			Debug1( LDAP_DEBUG_TRACE, "tlso_session_pinning: "
+					"hash %s not recognised by OpenSSL\n", hashalg );
+			rc = -1;
+			goto done;
+		}
+
+#if OPENSSL_VERSION_NUMBER >= 0x10100000
+		mdctx = EVP_MD_CTX_new();
+#else
+		mdctx = EVP_MD_CTX_create();
+#endif
+		if ( !mdctx ) {
+			rc = -1;
+			goto done;
+		}
+
+		EVP_DigestInit_ex( mdctx, md, NULL );
+		EVP_DigestUpdate( mdctx, key.bv_val, key.bv_len );
+		EVP_DigestFinal_ex( mdctx, (unsigned char *)keyhash.bv_val, &len );
+		keyhash.bv_len = len;
+#if OPENSSL_VERSION_NUMBER >= 0x10100000
+		EVP_MD_CTX_free( mdctx );
+#else
+		EVP_MD_CTX_destroy( mdctx );
+#endif
+	} else {
+		keyhash = key;
+	}
+
+	if ( ber_bvcmp( hash, &keyhash ) ) {
+		rc = LDAP_CONNECT_ERROR;
+		Debug0( LDAP_DEBUG_ANY, "tlso_session_pinning: "
+				"public key hash does not match provided pin.\n" );
+		if ( ld->ld_error ) {
+			LDAP_FREE( ld->ld_error );
+		}
+		ld->ld_error = LDAP_STRDUP(
+			_("TLS: public key hash does not match provided pin"));
+	}
+
+done:
+	LDAP_FREE( key.bv_val );
+	X509_free( cert );
+	return rc;
+}
+
+/*
+ * TLS support for LBER Sockbufs
+ */
+
+struct tls_data {
+	tlso_session		*session;
+	Sockbuf_IO_Desc		*sbiod;
+};
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+#define BIO_set_init(b, x)	b->init = x
+#define BIO_set_data(b, x)	b->ptr = x
+#define BIO_clear_flags(b, x)	b->flags &= ~(x)
+#define BIO_get_data(b)	b->ptr
+#endif
+static int
+tlso_bio_create( BIO *b ) {
+	BIO_set_init( b, 1 );
+	BIO_set_data( b, NULL );
+	BIO_clear_flags( b, ~0 );
+	return 1;
+}
+
+static int
+tlso_bio_destroy( BIO *b )
+{
+	if ( b == NULL ) return 0;
+
+	BIO_set_data( b, NULL );		/* sb_tls_remove() will free it */
+	BIO_set_init( b, 0 );
+	BIO_clear_flags( b, ~0 );
+	return 1;
+}
+
+static int
+tlso_bio_read( BIO *b, char *buf, int len )
+{
+	struct tls_data		*p;
+	int			ret;
+		
+	if ( buf == NULL || len <= 0 ) return 0;
+
+	p = (struct tls_data *)BIO_get_data(b);
+
+	if ( p == NULL || p->sbiod == NULL ) {
+		return 0;
+	}
+
+	ret = LBER_SBIOD_READ_NEXT( p->sbiod, buf, len );
+
+	BIO_clear_retry_flags( b );
+	if ( ret < 0 ) {
+		int err = sock_errno();
+		if ( err == EAGAIN || err == EWOULDBLOCK ) {
+			BIO_set_retry_read( b );
+		}
+	}
+
+	return ret;
+}
+
+static int
+tlso_bio_write( BIO *b, const char *buf, int len )
+{
+	struct tls_data		*p;
+	int			ret;
+	
+	if ( buf == NULL || len <= 0 ) return 0;
+	
+	p = (struct tls_data *)BIO_get_data(b);
+
+	if ( p == NULL || p->sbiod == NULL ) {
+		return 0;
+	}
+
+	ret = LBER_SBIOD_WRITE_NEXT( p->sbiod, (char *)buf, len );
+
+	BIO_clear_retry_flags( b );
+	if ( ret < 0 ) {
+		int err = sock_errno();
+		if ( err == EAGAIN || err == EWOULDBLOCK ) {
+			BIO_set_retry_write( b );
+		}
+	}
+
+	return ret;
+}
+
+static long
+tlso_bio_ctrl( BIO *b, int cmd, long num, void *ptr )
+{
+	if ( cmd == BIO_CTRL_FLUSH ) {
+		/* The OpenSSL library needs this */
+		return 1;
+	}
+	return 0;
+}
+
+static int
+tlso_bio_gets( BIO *b, char *buf, int len )
+{
+	return -1;
+}
+
+static int
+tlso_bio_puts( BIO *b, const char *str )
+{
+	return tlso_bio_write( b, str, strlen( str ) );
+}
+
+static BIO_METHOD *
+tlso_bio_setup( void )
+{
+	/* it's a source/sink BIO */
+	BIO_METHOD * method = BIO_meth_new( 100 | 0x400, "sockbuf glue" );
+	BIO_meth_set_write( method, tlso_bio_write );
+	BIO_meth_set_read( method, tlso_bio_read );
+	BIO_meth_set_puts( method, tlso_bio_puts );
+	BIO_meth_set_gets( method, tlso_bio_gets );
+	BIO_meth_set_ctrl( method, tlso_bio_ctrl );
+	BIO_meth_set_create( method, tlso_bio_create );
+	BIO_meth_set_destroy( method, tlso_bio_destroy );
+
+	return method;
+}
+
+static int
+tlso_sb_setup( Sockbuf_IO_Desc *sbiod, void *arg )
+{
+	struct tls_data		*p;
+	BIO			*bio;
+
+	assert( sbiod != NULL );
+
+	p = LBER_MALLOC( sizeof( *p ) );
+	if ( p == NULL ) {
+		return -1;
+	}
+	
+	p->session = arg;
+	p->sbiod = sbiod;
+	bio = BIO_new( tlso_bio_method );
+	BIO_set_data( bio, p );
+	SSL_set_bio( p->session, bio, bio );
+	sbiod->sbiod_pvt = p;
+	return 0;
+}
+
+static int
+tlso_sb_remove( Sockbuf_IO_Desc *sbiod )
+{
+	struct tls_data		*p;
+	
+	assert( sbiod != NULL );
+	assert( sbiod->sbiod_pvt != NULL );
+
+	p = (struct tls_data *)sbiod->sbiod_pvt;
+	SSL_free( p->session );
+	LBER_FREE( sbiod->sbiod_pvt );
+	sbiod->sbiod_pvt = NULL;
+	return 0;
+}
+
+static int
+tlso_sb_close( Sockbuf_IO_Desc *sbiod )
+{
+	struct tls_data		*p;
+	
+	assert( sbiod != NULL );
+	assert( sbiod->sbiod_pvt != NULL );
+
+	p = (struct tls_data *)sbiod->sbiod_pvt;
+	SSL_shutdown( p->session );
+	return 0;
+}
+
+static int
+tlso_sb_ctrl( Sockbuf_IO_Desc *sbiod, int opt, void *arg )
+{
+	struct tls_data		*p;
+	
+	assert( sbiod != NULL );
+	assert( sbiod->sbiod_pvt != NULL );
+
+	p = (struct tls_data *)sbiod->sbiod_pvt;
+	
+	if ( opt == LBER_SB_OPT_GET_SSL ) {
+		*((tlso_session **)arg) = p->session;
+		return 1;
+
+	} else if ( opt == LBER_SB_OPT_DATA_READY ) {
+		if( SSL_pending( p->session ) > 0 ) {
+			return 1;
+		}
+	}
+	
+	return LBER_SBIOD_CTRL_NEXT( sbiod, opt, arg );
+}
+
+static ber_slen_t
+tlso_sb_read( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
+{
+	struct tls_data		*p;
+	ber_slen_t		ret;
+	int			err;
+
+	assert( sbiod != NULL );
+	assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
+
+	p = (struct tls_data *)sbiod->sbiod_pvt;
+
+	ret = SSL_read( p->session, (char *)buf, len );
+#ifdef HAVE_WINSOCK
+	errno = WSAGetLastError();
+#endif
+	err = SSL_get_error( p->session, ret );
+	if (err == SSL_ERROR_WANT_READ ) {
+		sbiod->sbiod_sb->sb_trans_needs_read = 1;
+		sock_errset(EWOULDBLOCK);
+	}
+	else
+		sbiod->sbiod_sb->sb_trans_needs_read = 0;
+	return ret;
+}
+
+static ber_slen_t
+tlso_sb_write( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
+{
+	struct tls_data		*p;
+	ber_slen_t		ret;
+	int			err;
+
+	assert( sbiod != NULL );
+	assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
+
+	p = (struct tls_data *)sbiod->sbiod_pvt;
+
+	ret = SSL_write( p->session, (char *)buf, len );
+#ifdef HAVE_WINSOCK
+	errno = WSAGetLastError();
+#endif
+	err = SSL_get_error( p->session, ret );
+	if (err == SSL_ERROR_WANT_WRITE ) {
+		sbiod->sbiod_sb->sb_trans_needs_write = 1;
+		sock_errset(EWOULDBLOCK);
+
+	} else {
+		sbiod->sbiod_sb->sb_trans_needs_write = 0;
+	}
+	return ret;
+}
+
+static Sockbuf_IO tlso_sbio =
+{
+	tlso_sb_setup,		/* sbi_setup */
+	tlso_sb_remove,		/* sbi_remove */
+	tlso_sb_ctrl,		/* sbi_ctrl */
+	tlso_sb_read,		/* sbi_read */
+	tlso_sb_write,		/* sbi_write */
+	tlso_sb_close		/* sbi_close */
+};
+
+/* Derived from openssl/apps/s_cb.c */
+static void
+tlso_info_cb( const SSL *ssl, int where, int ret )
+{
+	int w;
+	char *op;
+	char *state = (char *) SSL_state_string_long( (SSL *)ssl );
+
+	w = where & ~SSL_ST_MASK;
+	if ( w & SSL_ST_CONNECT ) {
+		op = "SSL_connect";
+	} else if ( w & SSL_ST_ACCEPT ) {
+		op = "SSL_accept";
+	} else {
+		op = "undefined";
+	}
+
+#ifdef HAVE_EBCDIC
+	if ( state ) {
+		state = LDAP_STRDUP( state );
+		__etoa( state );
+	}
+#endif
+	if ( where & SSL_CB_LOOP ) {
+		Debug2( LDAP_DEBUG_TRACE,
+			   "TLS trace: %s:%s\n",
+			   op, state );
+
+	} else if ( where & SSL_CB_ALERT ) {
+		char *atype = (char *) SSL_alert_type_string_long( ret );
+		char *adesc = (char *) SSL_alert_desc_string_long( ret );
+		op = ( where & SSL_CB_READ ) ? "read" : "write";
+#ifdef HAVE_EBCDIC
+		if ( atype ) {
+			atype = LDAP_STRDUP( atype );
+			__etoa( atype );
+		}
+		if ( adesc ) {
+			adesc = LDAP_STRDUP( adesc );
+			__etoa( adesc );
+		}
+#endif
+		Debug3( LDAP_DEBUG_TRACE,
+			   "TLS trace: SSL3 alert %s:%s:%s\n",
+			   op, atype, adesc );
+#ifdef HAVE_EBCDIC
+		if ( atype ) LDAP_FREE( atype );
+		if ( adesc ) LDAP_FREE( adesc );
+#endif
+	} else if ( where & SSL_CB_EXIT ) {
+		if ( ret == 0 ) {
+			Debug2( LDAP_DEBUG_TRACE,
+				   "TLS trace: %s:failed in %s\n",
+				   op, state );
+		} else if ( ret < 0 ) {
+			Debug2( LDAP_DEBUG_TRACE,
+				   "TLS trace: %s:error in %s\n",
+				   op, state );
+		}
+	}
+#ifdef HAVE_EBCDIC
+	if ( state ) LDAP_FREE( state );
+#endif
+}
+
+static int
+tlso_verify_cb( int ok, X509_STORE_CTX *ctx )
+{
+	X509 *cert;
+	int errnum;
+	int errdepth;
+	X509_NAME *subject;
+	X509_NAME *issuer;
+	char *sname;
+	char *iname;
+	char *certerr = NULL;
+
+	cert = X509_STORE_CTX_get_current_cert( ctx );
+	errnum = X509_STORE_CTX_get_error( ctx );
+	errdepth = X509_STORE_CTX_get_error_depth( ctx );
+
+	/*
+	 * X509_get_*_name return pointers to the internal copies of
+	 * those things requested.  So do not free them.
+	 */
+	subject = X509_get_subject_name( cert );
+	issuer = X509_get_issuer_name( cert );
+	/* X509_NAME_oneline, if passed a NULL buf, allocate memory */
+	sname = X509_NAME_oneline( subject, NULL, 0 );
+	iname = X509_NAME_oneline( issuer, NULL, 0 );
+	if ( !ok ) certerr = (char *)X509_verify_cert_error_string( errnum );
+#ifdef HAVE_EBCDIC
+	if ( sname ) __etoa( sname );
+	if ( iname ) __etoa( iname );
+	if ( certerr ) {
+		certerr = LDAP_STRDUP( certerr );
+		__etoa( certerr );
+	}
+#endif
+	Debug3( LDAP_DEBUG_TRACE,
+		   "TLS certificate verification: depth: %d, err: %d, subject: %s,",
+		   errdepth, errnum,
+		   sname ? sname : "-unknown-" );
+	Debug1( LDAP_DEBUG_TRACE, " issuer: %s\n", iname ? iname : "-unknown-" );
+	if ( !ok ) {
+		Debug1( LDAP_DEBUG_ANY,
+			"TLS certificate verification: Error, %s\n",
+			certerr );
+	}
+	if ( sname )
+		OPENSSL_free ( sname );
+	if ( iname )
+		OPENSSL_free ( iname );
+#ifdef HAVE_EBCDIC
+	if ( certerr ) LDAP_FREE( certerr );
+#endif
+	return ok;
+}
+
+static int
+tlso_verify_ok( int ok, X509_STORE_CTX *ctx )
+{
+	(void) tlso_verify_cb( ok, ctx );
+	return 1;
+}
+
+/* Inspired by ERR_print_errors in OpenSSL */
+static void
+tlso_report_error( void )
+{
+	unsigned long l;
+	char buf[200];
+	const char *file;
+	int line;
+
+	while ( ( l = ERR_get_error_line( &file, &line ) ) != 0 ) {
+		ERR_error_string_n( l, buf, sizeof( buf ) );
+#ifdef HAVE_EBCDIC
+		if ( file ) {
+			file = LDAP_STRDUP( file );
+			__etoa( (char *)file );
+		}
+		__etoa( buf );
+#endif
+		Debug3( LDAP_DEBUG_ANY, "TLS: %s %s:%d\n",
+			buf, file, line );
+#ifdef HAVE_EBCDIC
+		if ( file ) LDAP_FREE( (void *)file );
+#endif
+	}
+}
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+static RSA *
+tlso_tmp_rsa_cb( SSL *ssl, int is_export, int key_length )
+{
+	RSA *tmp_rsa;
+	/* FIXME:  Pregenerate the key on startup */
+	/* FIXME:  Who frees the key? */
+	BIGNUM *bn = BN_new();
+	tmp_rsa = NULL;
+	if ( bn ) {
+		if ( BN_set_word( bn, RSA_F4 )) {
+			tmp_rsa = RSA_new();
+			if ( tmp_rsa && !RSA_generate_key_ex( tmp_rsa, key_length, bn, NULL )) {
+				RSA_free( tmp_rsa );
+				tmp_rsa = NULL;
+			}
+		}
+		BN_free( bn );
+	}
+
+	if ( !tmp_rsa ) {
+		Debug2( LDAP_DEBUG_ANY,
+			"TLS: Failed to generate temporary %d-bit %s RSA key\n",
+			key_length, is_export ? "export" : "domestic" );
+	}
+	return tmp_rsa;
+}
+#endif /* OPENSSL_VERSION_NUMBER < 1.1 */
+
+static int
+tlso_seed_PRNG( const char *randfile )
+{
+#ifndef URANDOM_DEVICE
+	/* no /dev/urandom (or equiv) */
+	long total=0;
+	char buffer[MAXPATHLEN];
+
+	if (randfile == NULL) {
+		/* The seed file is $RANDFILE if defined, otherwise $HOME/.rnd.
+		 * If $HOME is not set or buffer too small to hold the pathname,
+		 * an error occurs.	- From RAND_file_name() man page.
+		 * The fact is that when $HOME is NULL, .rnd is used.
+		 */
+		randfile = RAND_file_name( buffer, sizeof( buffer ) );
+	}
+#ifndef OPENSSL_NO_EGD
+	else if (RAND_egd(randfile) > 0) {
+		/* EGD socket */
+		return 0;
+	}
+#endif
+
+	if (randfile == NULL) {
+		Debug0( LDAP_DEBUG_ANY,
+			"TLS: Use configuration file or $RANDFILE to define seed PRNG\n" );
+		return -1;
+	}
+
+	total = RAND_load_file(randfile, -1);
+
+	if (RAND_status() == 0) {
+		Debug0( LDAP_DEBUG_ANY,
+			"TLS: PRNG not been seeded with enough data\n" );
+		return -1;
+	}
+
+	/* assume if there was enough bits to seed that it's okay
+	 * to write derived bits to the file
+	 */
+	RAND_write_file(randfile);
+
+#endif
+
+	return 0;
+}
+
+
+tls_impl ldap_int_tls_impl = {
+	"OpenSSL",
+
+	tlso_init,
+	tlso_destroy,
+
+	tlso_ctx_new,
+	tlso_ctx_ref,
+	tlso_ctx_free,
+	tlso_ctx_init,
+
+	tlso_session_new,
+	tlso_session_connect,
+	tlso_session_accept,
+	tlso_session_upflags,
+	tlso_session_errmsg,
+	tlso_session_my_dn,
+	tlso_session_peer_dn,
+	tlso_session_chkhost,
+	tlso_session_strength,
+	tlso_session_unique,
+	tlso_session_endpoint,
+	tlso_session_version,
+	tlso_session_cipher,
+	tlso_session_peercert,
+	tlso_session_pinning,
+
+	&tlso_sbio,
+
+#ifdef LDAP_R_COMPILE
+	tlso_thr_init,
+#else
+	NULL,
+#endif
+
+	0
+};
+
+#endif /* HAVE_OPENSSL */