]> git.sur5r.net Git - openldap/blobdiff - servers/slapd/acl.c
Per ITS#419, don't require SLAPD_RLOOKUPS when HAVE_TCPD
[openldap] / servers / slapd / acl.c
index 904fcb6a9cb9c0d4b10f996a05a5f8eec06a2faa..f50005d09f5198ee940891d3d3299c426c0c1ad4 100644 (file)
@@ -28,11 +28,17 @@ static slap_control_t acl_mask(
        regmatch_t *matches );
 
 #ifdef SLAPD_ACI_ENABLED
-static int aci_access_allowed(
+static int aci_mask(
        Backend *be,
        Operation *op,
-       Entry *e, char *attr, struct berval *aci,
-       regmatch_t *matches );
+       Entry *e, char *attr, struct berval *val, struct berval *aci,
+       regmatch_t *matches, slap_access_t *grant, slap_access_t *deny );
+
+char *supportedACIMechs[] = {
+                               "1.3.6.1.4.1.4203.666.7.1",     /* experimental draft aci family */
+                               "1.3.6.1.4.1.4203.666.7.2",     /* experimental OpenLDAP aci family */
+                               NULL
+               };
 #endif
 
 static int     regex_matches(char *pat, char *str, char *buf, regmatch_t *matches);
@@ -68,6 +74,7 @@ access_allowed(
 {
        int                             count;
        AccessControl   *a;
+       char accessmaskbuf[ACCESSMASK_MAXLEN];
        slap_access_mask_t mask;
        slap_control_t control;
 
@@ -168,9 +175,10 @@ access_allowed(
        }
 
        Debug( LDAP_DEBUG_ACL,
-               "=> access_allowed: %s access %s to \"%s\"\n",
+               "=> access_allowed: %s access %s by %s\n",
                access2str( access ),
-               ACL_GRANT(mask, access) ? "granted" : "denied", op->o_dn );
+               ACL_GRANT(mask, access) ? "granted" : "denied",
+               accessmask2str( mask, accessmaskbuf ) );
 
        return ACL_GRANT(mask, access);
 }
@@ -193,8 +201,6 @@ acl_get(
     regmatch_t *matches
 )
 {
-       AccessControl   *next;
-
        assert( e != NULL );
        assert( count != NULL );
 
@@ -222,7 +228,7 @@ acl_get(
                                continue;
 
                        } else {
-                               Debug( LDAP_DEBUG_ACL, "=> acl_get: ACL [%d] matched\n",
+                               Debug( LDAP_DEBUG_ACL, "=> acl_get: [%d] matched\n",
                                        *count, 0, 0);
                        }
                }
@@ -276,19 +282,20 @@ acl_mask(
 {
        int             i;
        Access  *b;
+       char accessmaskbuf[ACCESSMASK_MAXLEN];
 
        assert( a != NULL );
        assert( mask != NULL );
 
        Debug( LDAP_DEBUG_ACL,
-               "=> acl_mask: access to entry \"%s\", attr \"%s\"\n requested\n",
+               "=> acl_mask: access to entry \"%s\", attr \"%s\" requested\n",
                e->e_dn, attr, 0 );
 
        Debug( LDAP_DEBUG_ACL,
                "=> acl_mask: to value \"%s\" by \"%s\", (%s) \n",
-               val ? val->bv_val : "any",
+               val ? val->bv_val : "*",
                op->o_ndn ?  op->o_ndn : "",
-               accessmask2str( *mask ) );
+               accessmask2str( *mask, accessmaskbuf ) );
 
        for ( i = 1, b = a->acl_access; b != NULL; b = b->a_next, i++ ) {
                slap_access_mask_t oldmask, modmask;
@@ -304,12 +311,17 @@ acl_mask(
                         * user is bound as somebody in the same namespace as
                         * the entry, OR the given dn matches the dn pattern
                         */
-                       if ( strcasecmp( b->a_dn_pat, "anonymous" ) == 0 ) {
+                       if ( strcmp( b->a_dn_pat, "anonymous" ) == 0 ) {
                                if (op->o_ndn != NULL && op->o_ndn[0] != '\0' ) {
                                        continue;
                                }
 
-                       } else if ( strcasecmp( b->a_dn_pat, "self" ) == 0 ) {
+                       } else if ( strcmp( b->a_dn_pat, "users" ) == 0 ) {
+                               if (op->o_ndn == NULL || op->o_ndn[0] == '\0' ) {
+                                       continue;
+                               }
+
+                       } else if ( strcmp( b->a_dn_pat, "self" ) == 0 ) {
                                if( op->o_ndn == NULL || op->o_ndn[0] == '\0' ) {
                                        continue;
                                }
@@ -318,10 +330,13 @@ acl_mask(
                                        continue;
                                }
 
-                       } else if ( strcmp( b->a_dn_pat, ".*" ) != 0 &&
-                               !regex_matches( b->a_dn_pat, op->o_ndn, e->e_ndn, matches ) )
-                       {
-                               continue;
+                       } else if ( strcmp( b->a_dn_pat, "*" ) != 0 ) {
+                               int ret = regex_matches( b->a_dn_pat,
+                                       op->o_ndn, e->e_ndn, matches );
+
+                               if( ret == 0 ) {
+                                       continue;
+                               }
                        }
                }
 
@@ -329,7 +344,7 @@ acl_mask(
                        Debug( LDAP_DEBUG_ACL, "<= check a_sockurl_pat: %s\n",
                                b->a_sockurl_pat, 0, 0 );
 
-                       if ( strcmp( b->a_sockurl_pat, ".*" ) != 0 &&
+                       if ( strcmp( b->a_sockurl_pat, "*" ) != 0 &&
                                !regex_matches( b->a_sockurl_pat, conn->c_listener_url,
                                e->e_ndn, matches ) ) 
                        {
@@ -341,7 +356,7 @@ acl_mask(
                        Debug( LDAP_DEBUG_ACL, "<= check a_domain_pat: %s\n",
                                b->a_domain_pat, 0, 0 );
 
-                       if ( strcmp( b->a_domain_pat, ".*" ) != 0 &&
+                       if ( strcmp( b->a_domain_pat, "*" ) != 0 &&
                                !regex_matches( b->a_domain_pat, conn->c_peer_domain,
                                e->e_ndn, matches ) ) 
                        {
@@ -353,7 +368,7 @@ acl_mask(
                        Debug( LDAP_DEBUG_ACL, "<= check a_peername_path: %s\n",
                                b->a_peername_pat, 0, 0 );
 
-                       if ( strcmp( b->a_peername_pat, ".*" ) != 0 &&
+                       if ( strcmp( b->a_peername_pat, "*" ) != 0 &&
                                !regex_matches( b->a_peername_pat, conn->c_peer_name,
                                e->e_ndn, matches ) )
                        {
@@ -365,7 +380,7 @@ acl_mask(
                        Debug( LDAP_DEBUG_ACL, "<= check a_sockname_path: %s\n",
                                b->a_sockname_pat, 0, 0 );
 
-                       if ( strcmp( b->a_sockname_pat, ".*" ) != 0 &&
+                       if ( strcmp( b->a_sockname_pat, "*" ) != 0 &&
                                !regex_matches( b->a_sockname_pat, conn->c_sock_name,
                                e->e_ndn, matches ) )
                        {
@@ -425,6 +440,7 @@ acl_mask(
 #ifdef SLAPD_ACI_ENABLED
                if ( b->a_aci_at != NULL ) {
                        Attribute       *at;
+                       slap_access_t grant, deny, tgrant, tdeny;
 
                        /* this case works different from the others above.
                         * since aci's themselves give permissions, we need
@@ -439,10 +455,10 @@ acl_mask(
                                continue;
                        }
 
-                       /* first check if the right being requested is
-                        * higher than allowed by the ACL clause.
+                       /* first check if the right being requested
+                        * is allowed by the ACL clause.
                         */
-                       if ( ! ACL_GRANT( b->a_mask, access ) ) {
+                       if ( ! ACL_GRANT( b->a_mask, *mask ) ) {
                                continue;
                        }
 
@@ -452,26 +468,51 @@ acl_mask(
                                continue;
                        }
 
+                       /* start out with nothing granted, nothing denied */
+                       ACL_INIT(tgrant);
+                       ACL_INIT(tdeny);
+
                        /* the aci is an multi-valued attribute.  The
                         * rights are determined by OR'ing the individual
                         * rights given by the acis.
                         */
                        for ( i = 0; at->a_vals[i] != NULL; i++ ) {
-                               if ( aci_access_allowed( be, op,
-                                       e, attr, at->a_vals[i],
-                                       matches ) )
+                               if (aci_mask( be, op,
+                                       e, attr, val, at->a_vals[i],
+                                       matches, &grant, &deny ) != 0)
                                {
-                                       Debug( LDAP_DEBUG_ACL,
-                                               "<= acl_mask: matched by clause #%d access granted\n",
-                                               i, 0, 0 );
-                                       break;
+                                       tgrant |= grant;
+                                       tdeny |= deny;
                                }
                        }
 
-                       if( ACL_IS_INVALID( modmask ) ) { 
+                       /* remove anything that the ACL clause does not allow */
+                       tgrant &= b->a_mask & ACL_PRIV_MASK;
+                       tdeny &= ACL_PRIV_MASK;
+
+                       /* see if we have anything to contribute */
+                       if( ACL_IS_INVALID(tgrant) && ACL_IS_INVALID(tdeny) ) { 
                                continue;
                        }
 
+                       /* this could be improved by changing acl_mask so that it can deal with
+                        * by clauses that return grant/deny pairs.  Right now, it does either
+                        * additive or subtractive rights, but not both at the same time.  So,
+                        * we need to combine the grant/deny pair into a single rights mask in
+                        * a smart way:  if either grant or deny is "empty", then we use the
+                        * opposite as is, otherwise we remove any denied rights from the grant
+                        * rights mask and construct an additive mask.
+                        */
+                       if (ACL_IS_INVALID(tdeny)) {
+                               modmask = tgrant | ACL_PRIV_ADDITIVE;
+
+                       } else if (ACL_IS_INVALID(tgrant)) {
+                               modmask = tdeny | ACL_PRIV_SUBSTRACTIVE;
+
+                       } else {
+                               modmask = (tgrant & ~tdeny) | ACL_PRIV_ADDITIVE;
+                       }
+
                } else
 #endif
                {
@@ -480,28 +521,39 @@ acl_mask(
 
 
                Debug( LDAP_DEBUG_ACL,
-                       "<= acl_mask: matched clause #%d\n",
-                       i, 0, 0 );
-
+                       "<= acl_mask: [%d] applying %s (%s)\n",
+                       i, accessmask2str( modmask, accessmaskbuf ), 
+                       b->a_type == ACL_CONTINUE
+                               ? "continue"
+                               : b->a_type == ACL_BREAK
+                                       ? "break"
+                                       : "stop" );
+
+               /* save old mask */
                oldmask = *mask;
 
                if( ACL_IS_ADDITIVE(modmask) ) {
-                       ACL_PRIV_CLR( *mask, ACL_PRIV_LEVEL );
+                       /* add privs */
                        ACL_PRIV_SET( *mask, modmask );
-               
+
+                       /* cleanup */
+                       ACL_PRIV_CLR( *mask, ~ACL_PRIV_MASK );
+
                } else if( ACL_IS_SUBTRACTIVE(modmask) ) {
-                       ACL_PRIV_CLR( *mask, ACL_PRIV_LEVEL );
+                       /* substract privs */
                        ACL_PRIV_CLR( *mask, modmask );
 
+                       /* cleanup */
+                       ACL_PRIV_CLR( *mask, ~ACL_PRIV_MASK );
+
                } else {
-                       ACL_PRIV_ASSIGN( *mask, modmask );
+                       /* assign privs */
+                       *mask = modmask;
                }
 
                Debug( LDAP_DEBUG_ACL,
-                       "<= acl_mask: old (%s) mod (%s) new (%s)\n",
-                       accessmask2str(oldmask),
-                       accessmask2str(modmask),
-                       accessmask2str(*mask) );
+                       "<= acl_mask: [%d] mask: %s\n",
+                       i, accessmask2str(*mask, accessmaskbuf), 0 );
 
                if( b->a_type == ACL_CONTINUE ) {
                        continue;
@@ -510,10 +562,13 @@ acl_mask(
                        return ACL_BREAK;
 
                } else {
-                       break;
+                       return ACL_STOP;
                }
        }
 
+       Debug( LDAP_DEBUG_ACL,
+               "<= acl_mask: no more <who> clauses, returning %s (stop)\n",
+               accessmask2str(*mask, accessmaskbuf), 0, 0 );
        return ACL_STOP;
 }
 
@@ -568,8 +623,6 @@ acl_check_modlist(
        }
 
        for ( ; mlist != NULL; mlist = mlist->ml_next ) {
-               regmatch_t       matches[MAXREMATCHES];
-
                /* the lastmod attributes are ignored by ACL checking */
                if ( oc_check_no_usermod_attr( mlist->ml_type ) ) {
                        Debug( LDAP_DEBUG_ACL, "Operational attribute: %s access allowed\n",
@@ -641,9 +694,9 @@ aci_strbvcmp (char *s, struct berval *bv)
        if (res)
                return(res);
        len = strlen(s);
-       if (len > bv->bv_len)
+       if (len > (int)bv->bv_len)
                return(1);
-       if (len < bv->bv_len)
+       if (len < (int)bv->bv_len)
                return(-1);
        return(0);
 }
@@ -684,21 +737,20 @@ aci_get_part (struct berval *list, int ix, char sep, struct berval *bv)
 }
 
 static int
-aci_list_has_right(
-       struct berval *list,
-       slap_access_t access,
-       int action)
+aci_list_map_rights (
+       struct berval *list)
 {
        struct berval bv;
+       slap_access_t mask;
        int i;
-       slap_access_t right;
 
+       ACL_INIT(mask);
        for (i = 0; aci_get_part(list, i, ',', &bv) >= 0; i++) {
                if (bv.bv_len <= 0)
                        continue;
                switch (*bv.bv_val) {
                case 'c':
-                       right = ACL_COMPARE;
+                       ACL_PRIV_SET(mask, ACL_PRIV_COMPARE);
                        break;
                case 's':
                        /* **** NOTE: draft-ietf-ldapext-aci-model-0.3.txt defines
@@ -706,118 +758,130 @@ aci_list_has_right(
                         * that the right 's' means "search".  The latter definition
                         * is used here.
                         */
-                       right = ACL_SEARCH;
+                       ACL_PRIV_SET(mask, ACL_PRIV_SEARCH);
                        break;
                case 'r':
-                       right = ACL_READ;
+                       ACL_PRIV_SET(mask, ACL_PRIV_READ);
                        break;
                case 'w':
-                       right = ACL_WRITE;
+                       ACL_PRIV_SET(mask, ACL_PRIV_WRITE);
                        break;
                case 'x':
                        /* **** NOTE: draft-ietf-ldapext-aci-model-0.3.txt does not 
                         * define any equivalent to the AUTH right, so I've just used
                         * 'x' for now.
                         */
-                       right = ACL_AUTH;
+                       ACL_PRIV_SET(mask, ACL_PRIV_AUTH);
                        break;
                default:
-                       right = 0;
                        break;
                }
 
-#ifdef SLAPD_ACI_DISCRETE_RIGHTS
-               if (right & access) {
-                       return(action);
-               }
-#else
-               if (action != 0) {
-                       /* check granted */
-                       if (ACL_GRANT(right, access))
-                               return(1);
-               } else {
-                       /* check denied */
-                       if (right <= access)
-                               return(1);
-               }
-#endif
        }
-
-#ifdef SLAPD_ACI_DISCRETE_RIGHTS
-       return(!action);
-#else
-       return(0);
-#endif
+       return(mask);
 }
 
 static int
-aci_list_has_attr (struct berval *list, char *attr)
+aci_list_has_attr (struct berval *list, char *attr, struct berval *val)
 {
-       struct berval bv;
+       struct berval bv, left, right;
        int i;
 
        for (i = 0; aci_get_part(list, i, ',', &bv) >= 0; i++) {
-               if (aci_strbvcmp(attr, &bv) == 0) {
-                       return(1);
+               if (aci_get_part(&bv, 0, '=', &left) < 0
+                       || aci_get_part(&bv, 1, '=', &right) < 0)
+               {
+                       if (aci_strbvcmp(attr, &bv) == 0)
+                               return(1);
+               } else if (val == NULL) {
+                       if (aci_strbvcmp(attr, &left) == 0)
+                               return(1);
+               } else {
+                       if (aci_strbvcmp(attr, &left) == 0) {
+                               /* this is experimental code that implements a
+                                * simple (prefix) match of the attribute value.
+                                * the ACI draft does not provide for aci's that
+                                * apply to specific values, but it would be
+                                * nice to have.  If the <attr> part of an aci's
+                                * rights list is of the form <attr>=<value>,
+                                * that means the aci applies only to attrs with
+                                * the given value.  Furthermore, if the attr is
+                                * of the form <attr>=<value>*, then <value> is
+                                * treated as a prefix, and the aci applies to 
+                                * any value with that prefix.
+                                *
+                                * Ideally, this would allow r.e. matches.
+                                */
+                               if (aci_get_part(&right, 0, '*', &left) < 0
+                                       || right.bv_len <= left.bv_len)
+                               {
+                                       if (aci_strbvcmp(val->bv_val, &right) == 0)
+                                               return(1);
+                               } else if (val->bv_len >= left.bv_len) {
+                                       if (strncasecmp( val->bv_val, left.bv_val, left.bv_len ) == 0)
+                                               return(1);
+                               }
+                       }
                }
        }
        return(0);
 }
 
-static int
-aci_list_has_attr_right (struct berval *list, char *attr, int access, int action)
+static slap_access_t
+aci_list_get_attr_rights (struct berval *list, char *attr, struct berval *val)
 {
     struct berval bv;
-    int i, found;
+    slap_access_t mask;
+    int i;
 
        /* loop through each rights/attr pair, skip first part (action) */
-       found = -1;
+       ACL_INIT(mask);
        for (i = 1; aci_get_part(list, i + 1, ';', &bv) >= 0; i += 2) {
-               if (aci_list_has_attr(&bv, attr) == 0)
+               if (aci_list_has_attr(&bv, attr, val) == 0)
                        continue;
-               found = 0;
                if (aci_get_part(list, i, ';', &bv) < 0)
                        continue;
-               if (aci_list_has_right(&bv, access, action) != 0)
-                       return(1);
+               mask |= aci_list_map_rights(&bv);
        }
-       return(found);
+       return(mask);
 }
 
 static int
-aci_list_has_permission(
+aci_list_get_rights (
        struct berval *list,
        char *attr,
-       slap_access_t access)
+       struct berval *val,
+       slap_access_t *grant,
+       slap_access_t *deny)
 {
     struct berval perm, actn;
-    int i, action, specific, general;
+    slap_access_t *mask;
+    int i, found;
 
        if (attr == NULL || *attr == 0 || strcasecmp(attr, "entry") == 0) {
                attr = "[entry]";
        }
 
+       found = 0;
+       ACL_INIT(*grant);
+       ACL_INIT(*deny);
        /* loop through each permissions clause */
        for (i = 0; aci_get_part(list, i, '$', &perm) >= 0; i++) {
                if (aci_get_part(&perm, 0, ';', &actn) < 0)
                        continue;
                if (aci_strbvcmp( "grant", &actn ) == 0) {
-                       action = 1;
+                       mask = grant;
                } else if (aci_strbvcmp( "deny", &actn ) == 0) {
-                       action = 0;
+                       mask = deny;
                } else {
                        continue;
                }
 
-               specific = aci_list_has_attr_right(&perm, attr, access, action);
-               if (specific >= 0)
-                       return(specific);
-
-               general = aci_list_has_attr_right(&perm, "[all]", access, action);
-               if (general >= 0)
-                       return(general);
+               found = 1;
+               *mask |= aci_list_get_attr_rights(&perm, attr, val);
+               *mask |= aci_list_get_attr_rights(&perm, "[all]", NULL);
        }
-       return(0);
+       return(found);
 }
 
 static int
@@ -869,34 +933,26 @@ aci_group_member (
 }
 
 static int
-aci_access_allowed (
-    struct berval      *aci,
-    char                       *attr,
+aci_mask (
     Backend                    *be,
-    Entry                      *e,
     Operation          *op,
-    slap_access_t      access,
-       regmatch_t              *matches
+    Entry                      *e,
+    char                       *attr,
+    struct berval      *val,
+    struct berval      *aci,
+       regmatch_t              *matches,
+       slap_access_t   *grant,
+       slap_access_t   *deny
 )
 {
     struct berval bv, perms, sdn;
     char *subjdn;
-       int rc;
-
-       Debug( LDAP_DEBUG_ACL,
-               "=> aci_access_allowed: %s access to entry \"%s\"\n",
-               access2str( access ), e->e_dn, 0 );
-
-       Debug( LDAP_DEBUG_ACL,
-               "=> aci_access_allowed: %s access to attribute \"%s\" by \"%s\"\n",
-           access2str( access ),
-               attr,
-               op->o_ndn ? op->o_ndn : "" );
+       int rc, i;
 
        /* parse an aci of the form:
                oid#scope#action;rights;attr;rights;attr$action;rights;attr;rights;attr#dnType#subjectDN
 
-          See draft-ietf-ldapext-aci-model-0.3.txt section 9.1 for
+          See draft-ietf-ldapext-aci-model-04.txt section 9.1 for
           a full description of the format for this attribute.
 
           For now, this routine only supports scope=entry.
@@ -906,6 +962,16 @@ aci_access_allowed (
        if (aci_get_part(aci, 4, '#', NULL) < 0)
                return(0);
 
+       /* check that the aci family is supported */
+       if (aci_get_part(aci, 0, '#', &bv) < 0)
+               return(0);
+       for (i = 0; supportedACIMechs[i] != NULL; i++) {
+               if (aci_strbvcmp( supportedACIMechs[i], &bv ) == 0)
+                       break;
+       }
+       if (supportedACIMechs[i] == NULL)
+               return(0);
+
        /* check that the scope is "entry" */
        if (aci_get_part(aci, 1, '#', &bv) < 0
                || aci_strbvcmp( "entry", &bv ) != 0)
@@ -918,7 +984,7 @@ aci_access_allowed (
                return(0);
 
        /* check if any permissions allow desired access */
-       if (aci_list_has_permission(&perms, attr, access) == 0)
+       if (aci_list_get_rights(&perms, attr, val, grant, deny) == 0)
                return(0);
 
        /* see if we have a DN match */
@@ -927,31 +993,59 @@ aci_access_allowed (
 
        if (aci_get_part(aci, 4, '#', &sdn) < 0)
                return(0);
+
        if (aci_strbvcmp( "access-id", &bv ) == 0) {
                subjdn = aci_bvstrdup(&sdn);
                if (subjdn == NULL)
                        return(0);
-               rc = 0;
+               rc = 1;
                if ( dn_normalize(subjdn) != NULL )
-                       rc = (strcasecmp(op->o_ndn, subjdn) == 0);
+                       if (strcasecmp(op->o_ndn, subjdn) != 0)
+                               rc = 0;
                ch_free(subjdn);
                return(rc);
        }
 
        if (aci_strbvcmp( "self", &bv ) == 0) {
-               return(strcasecmp(op->o_ndn, e->e_ndn) == 0);
-       }
+               if (strcasecmp(op->o_ndn, e->e_ndn) == 0)
+                       return(1);
 
-       if (aci_strbvcmp( "group", &bv ) == 0) {
-               return(aci_group_member(&sdn, "groupOfNames", "member", be, e, op, matches));
-       }
+       } else if (aci_strbvcmp( "dnattr", &bv ) == 0) {
+               Attribute *at;
+               char *attrname;
 
-       if (aci_strbvcmp( "role", &bv ) == 0) {
-               return(aci_group_member(&sdn, "organizationalRole", "roleOccupant", be, e, op, matches));
+               attrname = aci_bvstrdup(&sdn);
+               at = attr_find(e->e_attrs, attrname);
+               ch_free(attrname);
+
+               if (at != NULL) {
+                       bv.bv_val = op->o_ndn;
+                       bv.bv_len = strlen( bv.bv_val );
+
+                       if (value_find( at->a_vals, &bv, at->a_syntax, 3 ) == 0 )
+                               return(1);
+               }
+
+       } else if (aci_strbvcmp( "group", &bv ) == 0) {
+               if (aci_group_member(&sdn, "groupOfNames", "member", be, e, op, matches))
+                       return(1);
+
+       } else if (aci_strbvcmp( "role", &bv ) == 0) {
+               if (aci_group_member(&sdn, "organizationalRole", "roleOccupant", be, e, op, matches))
+                       return(1);
        }
 
        return(0);
 }
+
+char *
+get_supported_acimech (int index)
+{
+       if (index < 0 || index >= (sizeof(supportedACIMechs) / sizeof(char *)))
+               return(NULL);
+       return(supportedACIMechs[index]);
+}
+
 #endif /* SLAPD_ACI_ENABLED */
 
 static void
@@ -969,6 +1063,7 @@ string_expand(
 
        size = 0;
        newbuf[0] = '\0';
+       bufsiz--; /* leave space for lone $ */
 
        flag = 0;
        for ( dp = newbuf, sp = pat; size < bufsiz && *sp ; sp++) {
@@ -1002,6 +1097,13 @@ string_expand(
                        }
                }
        }
+
+       if (flag) {
+               /* must have ended with a single $ */
+               *dp++ = '$';
+               size++;
+       }
+
        *dp = '\0';
 
        Debug( LDAP_DEBUG_TRACE, "=> string_expand: pattern:  %s\n", pat, 0, 0 );