1 files changed, 444 insertions, 0 deletions

diff --git a/servers/slapd/bind.c b/servers/slapd/bind.c
new file mode 100644
index 0000000..254f3d6
--- /dev/null
+++ b/servers/slapd/bind.c
@@ -0,0 +1,444 @@
+/* bind.c - decode an ldap bind operation and pass it to a backend db */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 1998-2021 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>.
+ */
+/* Portions Copyright (c) 1995 Regents of the University of Michigan.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this notice is preserved and that due credit is given
+ * to the University of Michigan at Ann Arbor. The name of the University
+ * may not be used to endorse or promote products derived from this
+ * software without specific prior written permission. This software
+ * is provided ``as is'' without express or implied warranty.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+
+#include <ac/string.h>
+#include <ac/socket.h>
+
+#include "slap.h"
+
+int
+do_bind(
+    Operation	*op,
+    SlapReply	*rs )
+{
+	BerElement *ber = op->o_ber;
+	ber_int_t version;
+	ber_tag_t method;
+	struct berval mech = BER_BVNULL;
+	struct berval dn = BER_BVNULL;
+	ber_tag_t tag;
+	Backend *be = NULL;
+
+	Debug( LDAP_DEBUG_TRACE, "%s do_bind\n",
+		op->o_log_prefix, 0, 0 );
+
+	/*
+	 * Force the connection to "anonymous" until bind succeeds.
+	 */
+	ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
+	if ( op->o_conn->c_sasl_bind_in_progress ) {
+		be = op->o_conn->c_authz_backend;
+	}
+	if ( !BER_BVISEMPTY( &op->o_conn->c_dn ) ) {
+		/* log authorization identity demotion */
+		Statslog( LDAP_DEBUG_STATS,
+			"%s BIND anonymous mech=implicit ssf=0\n",
+			op->o_log_prefix, 0, 0, 0, 0 );
+	}
+	connection2anonymous( op->o_conn );
+	if ( op->o_conn->c_sasl_bind_in_progress ) {
+		op->o_conn->c_authz_backend = be;
+	}
+	ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
+	if ( !BER_BVISNULL( &op->o_dn ) ) {
+		/* NOTE: temporarily wasting few bytes
+		 * (until bind is completed), but saving
+		 * a couple of ch_free() and ch_strdup("") */ 
+		op->o_dn.bv_val[0] = '\0';
+		op->o_dn.bv_len = 0;
+	}
+	if ( !BER_BVISNULL( &op->o_ndn ) ) {
+		op->o_ndn.bv_val[0] = '\0';
+		op->o_ndn.bv_len = 0;
+	}
+
+	/*
+	 * Parse the bind request.  It looks like this:
+	 *
+	 *	BindRequest ::= SEQUENCE {
+	 *		version		INTEGER,		 -- version
+	 *		name		DistinguishedName,	 -- dn
+	 *		authentication	CHOICE {
+	 *			simple		[0] OCTET STRING -- passwd
+	 *			krbv42ldap	[1] OCTET STRING -- OBSOLETE
+	 *			krbv42dsa	[2] OCTET STRING -- OBSOLETE
+	 *			SASL		[3] SaslCredentials
+	 *		}
+	 *	}
+	 *
+	 *	SaslCredentials ::= SEQUENCE {
+	 *		mechanism	    LDAPString,
+	 *		credentials	    OCTET STRING OPTIONAL
+	 *	}
+	 */
+
+	tag = ber_scanf( ber, "{imt" /*}*/, &version, &dn, &method );
+
+	if ( tag == LBER_ERROR ) {
+		Debug( LDAP_DEBUG_ANY, "%s do_bind: ber_scanf failed\n",
+			op->o_log_prefix, 0, 0 );
+		send_ldap_discon( op, rs, LDAP_PROTOCOL_ERROR, "decoding error" );
+		rs->sr_err = SLAPD_DISCONNECT;
+		goto cleanup;
+	}
+
+	op->o_protocol = version;
+	op->orb_method = method;
+
+	if( op->orb_method != LDAP_AUTH_SASL ) {
+		tag = ber_scanf( ber, /*{*/ "m}", &op->orb_cred );
+
+	} else {
+		tag = ber_scanf( ber, "{m" /*}*/, &mech );
+
+		if ( tag != LBER_ERROR ) {
+			ber_len_t len;
+			tag = ber_peek_tag( ber, &len );
+
+			if ( tag == LDAP_TAG_LDAPCRED ) { 
+				tag = ber_scanf( ber, "m", &op->orb_cred );
+			} else {
+				tag = LDAP_TAG_LDAPCRED;
+				BER_BVZERO( &op->orb_cred );
+			}
+
+			if ( tag != LBER_ERROR ) {
+				tag = ber_scanf( ber, /*{{*/ "}}" );
+			}
+		}
+	}
+
+	if ( tag == LBER_ERROR ) {
+		Debug( LDAP_DEBUG_ANY, "%s do_bind: ber_scanf failed\n",
+			op->o_log_prefix, 0, 0 );
+		send_ldap_discon( op, rs, LDAP_PROTOCOL_ERROR, "decoding error" );
+		rs->sr_err = SLAPD_DISCONNECT;
+		goto cleanup;
+	}
+
+	if( get_ctrls( op, rs, 1 ) != LDAP_SUCCESS ) {
+		Debug( LDAP_DEBUG_ANY, "%s do_bind: get_ctrls failed\n",
+			op->o_log_prefix, 0, 0 );
+		goto cleanup;
+	} 
+
+	/* We use the tmpmemctx here because it speeds up normalization.
+	 * However, we must dup with regular malloc when storing any
+	 * resulting DNs in the op or conn structures.
+	 */
+	rs->sr_err = dnPrettyNormal( NULL, &dn, &op->o_req_dn, &op->o_req_ndn,
+		op->o_tmpmemctx );
+	if ( rs->sr_err != LDAP_SUCCESS ) {
+		Debug( LDAP_DEBUG_ANY, "%s do_bind: invalid dn (%s)\n",
+			op->o_log_prefix, dn.bv_val, 0 );
+		send_ldap_error( op, rs, LDAP_INVALID_DN_SYNTAX, "invalid DN" );
+		goto cleanup;
+	}
+
+	Statslog( LDAP_DEBUG_STATS, "%s BIND dn=\"%s\" method=%ld\n",
+	    op->o_log_prefix, op->o_req_dn.bv_val,
+		(unsigned long) op->orb_method, 0, 0 );
+
+	if( op->orb_method == LDAP_AUTH_SASL ) {
+		Debug( LDAP_DEBUG_TRACE, "do_bind: dn (%s) SASL mech %s\n",
+			op->o_req_dn.bv_val, mech.bv_val, NULL );
+
+	} else {
+		Debug( LDAP_DEBUG_TRACE,
+			"do_bind: version=%ld dn=\"%s\" method=%ld\n",
+			(unsigned long) version, op->o_req_dn.bv_val,
+			(unsigned long) op->orb_method );
+	}
+
+	if ( version < LDAP_VERSION_MIN || version > LDAP_VERSION_MAX ) {
+		Debug( LDAP_DEBUG_ANY, "%s do_bind: unknown version=%ld\n",
+			op->o_log_prefix, (unsigned long) version, 0 );
+		send_ldap_error( op, rs, LDAP_PROTOCOL_ERROR,
+			"requested protocol version not supported" );
+		goto cleanup;
+
+	} else if (!( global_allows & SLAP_ALLOW_BIND_V2 ) &&
+		version < LDAP_VERSION3 )
+	{
+		send_ldap_error( op, rs, LDAP_PROTOCOL_ERROR,
+			"historical protocol version requested, use LDAPv3 instead" );
+		goto cleanup;
+	}
+
+	/*
+	 * we set connection version regardless of whether bind succeeds or not.
+	 */
+	ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
+	op->o_conn->c_protocol = version;
+	ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
+
+	op->orb_mech = mech;
+
+	op->o_bd = frontendDB;
+	rs->sr_err = frontendDB->be_bind( op, rs );
+
+cleanup:
+	if ( rs->sr_err == LDAP_SUCCESS ) {
+		if ( op->orb_method != LDAP_AUTH_SASL ) {
+			ber_dupbv( &op->o_conn->c_authmech, &mech );
+		}
+		op->o_conn->c_authtype = op->orb_method;
+	}
+
+	if( !BER_BVISNULL( &op->o_req_dn ) ) {
+		slap_sl_free( op->o_req_dn.bv_val, op->o_tmpmemctx );
+		BER_BVZERO( &op->o_req_dn );
+	}
+	if( !BER_BVISNULL( &op->o_req_ndn ) ) {
+		slap_sl_free( op->o_req_ndn.bv_val, op->o_tmpmemctx );
+		BER_BVZERO( &op->o_req_ndn );
+	}
+
+	return rs->sr_err;
+}
+
+int
+fe_op_bind( Operation *op, SlapReply *rs )
+{
+	BackendDB	*bd = op->o_bd;
+
+	/* check for inappropriate controls */
+	if( get_manageDSAit( op ) == SLAP_CONTROL_CRITICAL ) {
+		send_ldap_error( op, rs,
+			LDAP_UNAVAILABLE_CRITICAL_EXTENSION,
+			"manageDSAit control inappropriate" );
+		goto cleanup;
+	}
+
+	if ( op->orb_method == LDAP_AUTH_SASL ) {
+		if ( op->o_protocol < LDAP_VERSION3 ) {
+			Debug( LDAP_DEBUG_ANY, "do_bind: sasl with LDAPv%ld\n",
+				(unsigned long)op->o_protocol, 0, 0 );
+			send_ldap_discon( op, rs,
+				LDAP_PROTOCOL_ERROR, "SASL bind requires LDAPv3" );
+			rs->sr_err = SLAPD_DISCONNECT;
+			goto cleanup;
+		}
+
+		if( BER_BVISNULL( &op->orb_mech ) || BER_BVISEMPTY( &op->orb_mech ) ) {
+			Debug( LDAP_DEBUG_ANY,
+				"do_bind: no sasl mechanism provided\n",
+				0, 0, 0 );
+			send_ldap_error( op, rs, LDAP_AUTH_METHOD_NOT_SUPPORTED,
+				"no SASL mechanism provided" );
+			goto cleanup;
+		}
+
+		/* check restrictions */
+		if( backend_check_restrictions( op, rs, &op->orb_mech ) != LDAP_SUCCESS ) {
+			send_ldap_result( op, rs );
+			goto cleanup;
+		}
+
+		ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
+		if ( op->o_conn->c_sasl_bind_in_progress ) {
+			if( !bvmatch( &op->o_conn->c_sasl_bind_mech, &op->orb_mech ) ) {
+				/* mechanism changed between bind steps */
+				slap_sasl_reset(op->o_conn);
+			}
+		} else {
+			ber_dupbv(&op->o_conn->c_sasl_bind_mech, &op->orb_mech);
+		}
+
+		/* Set the bindop for the benefit of in-directory SASL lookups */
+		op->o_conn->c_sasl_bindop = op;
+
+		ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
+
+		rs->sr_err = slap_sasl_bind( op, rs );
+
+		goto cleanup;
+
+	} else {
+		/* Not SASL, cancel any in-progress bind */
+		ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
+
+		if ( !BER_BVISNULL( &op->o_conn->c_sasl_bind_mech ) ) {
+			free( op->o_conn->c_sasl_bind_mech.bv_val );
+			BER_BVZERO( &op->o_conn->c_sasl_bind_mech );
+		}
+		op->o_conn->c_sasl_bind_in_progress = 0;
+
+		slap_sasl_reset( op->o_conn );
+		ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
+	}
+
+	if ( op->orb_method == LDAP_AUTH_SIMPLE ) {
+		BER_BVSTR( &op->orb_mech, "SIMPLE" );
+		/* accept "anonymous" binds */
+		if ( BER_BVISEMPTY( &op->orb_cred ) || BER_BVISEMPTY( &op->o_req_ndn ) ) {
+			rs->sr_err = LDAP_SUCCESS;
+
+			if( !BER_BVISEMPTY( &op->orb_cred ) &&
+				!( global_allows & SLAP_ALLOW_BIND_ANON_CRED ))
+			{
+				/* cred is not empty, disallow */
+				rs->sr_err = LDAP_INVALID_CREDENTIALS;
+
+			} else if ( !BER_BVISEMPTY( &op->o_req_ndn ) &&
+				!( global_allows & SLAP_ALLOW_BIND_ANON_DN ))
+			{
+				/* DN is not empty, disallow */
+				rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
+				rs->sr_text =
+					"unauthenticated bind (DN with no password) disallowed";
+
+			} else if ( global_disallows & SLAP_DISALLOW_BIND_ANON ) {
+				/* disallow */
+				rs->sr_err = LDAP_INAPPROPRIATE_AUTH;
+				rs->sr_text = "anonymous bind disallowed";
+
+			} else {
+				backend_check_restrictions( op, rs, &op->orb_mech );
+			}
+
+			/*
+			 * we already forced connection to "anonymous",
+			 * just need to send success
+			 */
+			send_ldap_result( op, rs );
+			Debug( LDAP_DEBUG_TRACE, "do_bind: v%d anonymous bind\n",
+				op->o_protocol, 0, 0 );
+			goto cleanup;
+
+		} else if ( global_disallows & SLAP_DISALLOW_BIND_SIMPLE ) {
+			/* disallow simple authentication */
+			rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
+			rs->sr_text = "unwilling to perform simple authentication";
+
+			send_ldap_result( op, rs );
+			Debug( LDAP_DEBUG_TRACE,
+				"do_bind: v%d simple bind(%s) disallowed\n",
+				op->o_protocol, op->o_req_ndn.bv_val, 0 );
+			goto cleanup;
+		}
+
+	} else {
+		rs->sr_err = LDAP_AUTH_METHOD_NOT_SUPPORTED;
+		rs->sr_text = "unknown authentication method";
+
+		send_ldap_result( op, rs );
+		Debug( LDAP_DEBUG_TRACE,
+			"do_bind: v%d unknown authentication method (%d)\n",
+			op->o_protocol, op->orb_method, 0 );
+		goto cleanup;
+	}
+
+	/*
+	 * We could be serving multiple database backends.  Select the
+	 * appropriate one, or send a referral to our "referral server"
+	 * if we don't hold it.
+	 */
+
+	if ( (op->o_bd = select_backend( &op->o_req_ndn, 0 )) == NULL ) {
+		/* don't return referral for bind requests */
+		/* noSuchObject is not allowed to be returned by bind */
+		rs->sr_err = LDAP_INVALID_CREDENTIALS;
+		op->o_bd = bd;
+		send_ldap_result( op, rs );
+		goto cleanup;
+	}
+
+	/* check restrictions */
+	if( backend_check_restrictions( op, rs, NULL ) != LDAP_SUCCESS ) {
+		send_ldap_result( op, rs );
+		goto cleanup;
+	}
+
+	if( op->o_bd->be_bind ) {
+		op->o_conn->c_authz_cookie = NULL;
+
+		rs->sr_err = (op->o_bd->be_bind)( op, rs );
+
+		if ( rs->sr_err == 0 ) {
+			(void)fe_op_bind_success( op, rs );
+
+		} else if ( !BER_BVISNULL( &op->orb_edn ) ) {
+			free( op->orb_edn.bv_val );
+			BER_BVZERO( &op->orb_edn );
+		}
+
+	} else {
+		send_ldap_error( op, rs, LDAP_UNWILLING_TO_PERFORM,
+			"operation not supported within naming context" );
+	}
+
+cleanup:;
+	op->o_bd = bd;
+	return rs->sr_err;
+}
+
+int
+fe_op_bind_success( Operation *op, SlapReply *rs )
+{
+	ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
+
+	if( op->o_conn->c_authz_backend == NULL ) {
+		op->o_conn->c_authz_backend = op->o_bd;
+	}
+
+	/* be_bind returns regular/global edn */
+	if( !BER_BVISEMPTY( &op->orb_edn ) ) {
+		op->o_conn->c_dn = op->orb_edn;
+	} else {
+		ber_dupbv(&op->o_conn->c_dn, &op->o_req_dn);
+	}
+
+	ber_dupbv( &op->o_conn->c_ndn, &op->o_req_ndn );
+
+	/* op->o_conn->c_sb may be 0 for internal operations */
+	if( !BER_BVISEMPTY( &op->o_conn->c_dn ) && op->o_conn->c_sb != 0 ) {
+		ber_len_t max = sockbuf_max_incoming_auth;
+		ber_sockbuf_ctrl( op->o_conn->c_sb,
+			LBER_SB_OPT_SET_MAX_INCOMING, &max );
+	}
+
+	/* log authorization identity */
+	Statslog( LDAP_DEBUG_STATS,
+		"%s BIND dn=\"%s\" mech=%s ssf=0\n",
+		op->o_log_prefix,
+		op->o_conn->c_dn.bv_val, op->orb_mech.bv_val, 0, 0 );
+
+	Debug( LDAP_DEBUG_TRACE,
+		"do_bind: v%d bind: \"%s\" to \"%s\"\n",
+		op->o_protocol, op->o_req_dn.bv_val, op->o_conn->c_dn.bv_val );
+
+	ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
+
+	/* send this here to avoid a race condition */
+	send_ldap_result( op, rs );
+
+	return LDAP_SUCCESS;
+}