]> git.sur5r.net Git - openldap/commitdiff
fix buffer overflow in ACL unparse (ITS#6611)
authorPierangelo Masarati <ando@openldap.org>
Tue, 17 Aug 2010 00:54:11 +0000 (00:54 +0000)
committerPierangelo Masarati <ando@openldap.org>
Tue, 17 Aug 2010 00:54:11 +0000 (00:54 +0000)
servers/slapd/aclparse.c

index e7f0407fd40af2fd191084c072dba2b3e4338b23..7a1b43314d242f29d1c19c0fa2929644034a6c5b 100644 (file)
@@ -57,6 +57,9 @@ const char *style_strings[] = {
        NULL
 };
 
+#define ACLBUF_CHUNKSIZE       8192
+static struct berval aclbuf;
+
 static void            split(char *line, int splitchar, char **left, char **right);
 static void            access_append(Access **l, Access *a);
 static void            access_free( Access *a );
@@ -2450,6 +2453,11 @@ acl_destroy( AccessControl *a )
                n = a->acl_next;
                acl_free( a );
        }
+
+       if ( !BER_BVISNULL( &aclbuf ) ) {
+               ch_free( aclbuf.bv_val );
+               BER_BVZERO( &aclbuf );
+       }
 }
 
 char *
@@ -2527,9 +2535,39 @@ str2access( const char *str )
        return( ACL_INVALID_ACCESS );
 }
 
-#define ACLBUF_MAXLEN  8192
+static char *
+safe_strncopy( char *ptr, const char *src, size_t n, struct berval *buf )
+{
+       while ( &ptr[n] >= &buf->bv_val[buf->bv_len] ) {
+               char *tmp = ch_realloc( buf->bv_val, 2*buf->bv_len );
+               if ( tmp == NULL ) {
+                       return NULL;
+               }
+               ptr = tmp + (ptr - buf->bv_val);
+               buf->bv_val = tmp;
+               buf->bv_len *= 2;
+       }
+
+       return lutil_strncopy( ptr, src, n );
+}
+
+static char *
+safe_strcopy( char *ptr, const char *s, struct berval *buf )
+{
+       size_t n = strlen( s );
+
+       return safe_strncopy( ptr, s, n, buf );
+}
+
+static char *
+safe_strbvcopy( char *ptr, const struct berval *bv, struct berval *buf )
+{
+       return safe_strncopy( ptr, bv->bv_val, bv->bv_len, buf );
+}
 
-static char aclbuf[ACLBUF_MAXLEN];
+#define acl_safe_strcopy( ptr, s ) safe_strcopy( (ptr), (s), &aclbuf )
+#define acl_safe_strncopy( ptr, s, n ) safe_strncopy( (ptr), (s), (n), &aclbuf )
+#define acl_safe_strbvcopy( ptr, bv ) safe_strbvcopy( (ptr), (bv), &aclbuf )
 
 static char *
 dnaccess2text( slap_dn_access *bdn, char *ptr, int is_realdn )
@@ -2537,7 +2575,7 @@ dnaccess2text( slap_dn_access *bdn, char *ptr, int is_realdn )
        *ptr++ = ' ';
 
        if ( is_realdn ) {
-               ptr = lutil_strcopy( ptr, "real" );
+               ptr = acl_safe_strcopy( ptr, "real" );
        }
 
        if ( ber_bvccmp( &bdn->a_pat, '*' ) ||
@@ -2549,33 +2587,34 @@ dnaccess2text( slap_dn_access *bdn, char *ptr, int is_realdn )
                        assert( ! ber_bvccmp( &bdn->a_pat, '*' ) );
                }
                        
-               ptr = lutil_strcopy( ptr, bdn->a_pat.bv_val );
+               ptr = acl_safe_strbvcopy( ptr, &bdn->a_pat );
                if ( bdn->a_style == ACL_STYLE_SELF && bdn->a_self_level != 0 ) {
-                       int n = sprintf( ptr, ".level{%d}", bdn->a_self_level );
+                       char buf[SLAP_TEXT_BUFLEN];
+                       int n = snprintf( buf, sizeof(buf), ".level{%d}", bdn->a_self_level );
                        if ( n > 0 ) {
-                               ptr += n;
+                               ptr = acl_safe_strncopy( ptr, buf, n );
                        } /* else ? */
                }
 
        } else {
-               ptr = lutil_strcopy( ptr, "dn." );
+               ptr = acl_safe_strcopy( ptr, "dn." );
                if ( bdn->a_style == ACL_STYLE_BASE )
-                       ptr = lutil_strcopy( ptr, style_base );
+                       ptr = acl_safe_strcopy( ptr, style_base );
                else 
-                       ptr = lutil_strcopy( ptr, style_strings[bdn->a_style] );
+                       ptr = acl_safe_strcopy( ptr, style_strings[bdn->a_style] );
                if ( bdn->a_style == ACL_STYLE_LEVEL ) {
-                       int n = sprintf( ptr, "{%d}", bdn->a_level );
+                       char buf[SLAP_TEXT_BUFLEN];
+                       int n = snprintf( buf, sizeof(buf), "{%d}", bdn->a_level );
                        if ( n > 0 ) {
-                               ptr += n;
+                               ptr = acl_safe_strncopy( ptr, buf, n );
                        } /* else ? */
                }
                if ( bdn->a_expand ) {
-                       ptr = lutil_strcopy( ptr, ",expand" );
+                       ptr = acl_safe_strcopy( ptr, ",expand" );
                }
-               *ptr++ = '=';
-               *ptr++ = '"';
-               ptr = lutil_strcopy( ptr, bdn->a_pat.bv_val );
-               *ptr++ = '"';
+               ptr = acl_safe_strcopy( ptr, "=\"" );
+               ptr = acl_safe_strbvcopy( ptr, &bdn->a_pat );
+               ptr = acl_safe_strcopy( ptr, "\"" );
        }
        return ptr;
 }
@@ -2585,88 +2624,83 @@ access2text( Access *b, char *ptr )
 {
        char maskbuf[ACCESSMASK_MAXLEN];
 
-       ptr = lutil_strcopy( ptr, "\tby" );
+       ptr = acl_safe_strcopy( ptr, "\tby" );
 
        if ( !BER_BVISEMPTY( &b->a_dn_pat ) ) {
                ptr = dnaccess2text( &b->a_dn, ptr, 0 );
        }
        if ( b->a_dn_at ) {
-               ptr = lutil_strcopy( ptr, " dnattr=" );
-               ptr = lutil_strcopy( ptr, b->a_dn_at->ad_cname.bv_val );
+               ptr = acl_safe_strcopy( ptr, " dnattr=" );
+               ptr = acl_safe_strbvcopy( ptr, &b->a_dn_at->ad_cname );
        }
 
        if ( !BER_BVISEMPTY( &b->a_realdn_pat ) ) {
                ptr = dnaccess2text( &b->a_realdn, ptr, 1 );
        }
        if ( b->a_realdn_at ) {
-               ptr = lutil_strcopy( ptr, " realdnattr=" );
-               ptr = lutil_strcopy( ptr, b->a_realdn_at->ad_cname.bv_val );
+               ptr = acl_safe_strcopy( ptr, " realdnattr=" );
+               ptr = acl_safe_strbvcopy( ptr, &b->a_realdn_at->ad_cname );
        }
 
        if ( !BER_BVISEMPTY( &b->a_group_pat ) ) {
-               ptr = lutil_strcopy( ptr, " group/" );
-               ptr = lutil_strcopy( ptr, b->a_group_oc ?
+               ptr = acl_safe_strcopy( ptr, " group/" );
+               ptr = acl_safe_strcopy( ptr, b->a_group_oc ?
                        b->a_group_oc->soc_cname.bv_val : SLAPD_GROUP_CLASS );
-               *ptr++ = '/';
-               ptr = lutil_strcopy( ptr, b->a_group_at ?
+               ptr = acl_safe_strcopy( ptr, "/" );
+               ptr = acl_safe_strcopy( ptr, b->a_group_at ?
                        b->a_group_at->ad_cname.bv_val : SLAPD_GROUP_ATTR );
-               *ptr++ = '.';
-               ptr = lutil_strcopy( ptr, style_strings[b->a_group_style] );
-               *ptr++ = '=';
-               *ptr++ = '"';
-               ptr = lutil_strcopy( ptr, b->a_group_pat.bv_val );
-               *ptr++ = '"';
+               ptr = acl_safe_strcopy( ptr, "." );
+               ptr = acl_safe_strcopy( ptr, style_strings[b->a_group_style] );
+               ptr = acl_safe_strcopy( ptr, "=\"" );
+               ptr = acl_safe_strbvcopy( ptr, &b->a_group_pat );
+               ptr = acl_safe_strcopy( ptr, "\"" );
        }
 
        if ( !BER_BVISEMPTY( &b->a_peername_pat ) ) {
-               ptr = lutil_strcopy( ptr, " peername" );
-               *ptr++ = '.';
-               ptr = lutil_strcopy( ptr, style_strings[b->a_peername_style] );
-               *ptr++ = '=';
-               *ptr++ = '"';
-               ptr = lutil_strcopy( ptr, b->a_peername_pat.bv_val );
-               *ptr++ = '"';
+               ptr = acl_safe_strcopy( ptr, " peername" );
+               ptr = acl_safe_strcopy( ptr, "." );
+               ptr = acl_safe_strcopy( ptr, style_strings[b->a_peername_style] );
+               ptr = acl_safe_strcopy( ptr, "=\"" );
+               ptr = acl_safe_strbvcopy( ptr, &b->a_peername_pat );
+               ptr = acl_safe_strcopy( ptr, "\"" );
        }
 
        if ( !BER_BVISEMPTY( &b->a_sockname_pat ) ) {
-               ptr = lutil_strcopy( ptr, " sockname" );
-               *ptr++ = '.';
-               ptr = lutil_strcopy( ptr, style_strings[b->a_sockname_style] );
-               *ptr++ = '=';
-               *ptr++ = '"';
-               ptr = lutil_strcopy( ptr, b->a_sockname_pat.bv_val );
-               *ptr++ = '"';
+               ptr = acl_safe_strcopy( ptr, " sockname" );
+               ptr = acl_safe_strcopy( ptr, "." );
+               ptr = acl_safe_strcopy( ptr, style_strings[b->a_sockname_style] );
+               ptr = acl_safe_strcopy( ptr, "=\"" );
+               ptr = acl_safe_strbvcopy( ptr, &b->a_sockname_pat );
+               ptr = acl_safe_strcopy( ptr, "\"" );
        }
 
        if ( !BER_BVISEMPTY( &b->a_domain_pat ) ) {
-               ptr = lutil_strcopy( ptr, " domain" );
-               *ptr++ = '.';
-               ptr = lutil_strcopy( ptr, style_strings[b->a_domain_style] );
+               ptr = acl_safe_strcopy( ptr, " domain" );
+               ptr = acl_safe_strcopy( ptr, "." );
+               ptr = acl_safe_strcopy( ptr, style_strings[b->a_domain_style] );
                if ( b->a_domain_expand ) {
-                       ptr = lutil_strcopy( ptr, ",expand" );
+                       ptr = acl_safe_strcopy( ptr, ",expand" );
                }
-               *ptr++ = '=';
-               ptr = lutil_strcopy( ptr, b->a_domain_pat.bv_val );
+               ptr = acl_safe_strcopy( ptr, "=" );
+               ptr = acl_safe_strbvcopy( ptr, &b->a_domain_pat );
        }
 
        if ( !BER_BVISEMPTY( &b->a_sockurl_pat ) ) {
-               ptr = lutil_strcopy( ptr, " sockurl" );
-               *ptr++ = '.';
-               ptr = lutil_strcopy( ptr, style_strings[b->a_sockurl_style] );
-               *ptr++ = '=';
-               *ptr++ = '"';
-               ptr = lutil_strcopy( ptr, b->a_sockurl_pat.bv_val );
-               *ptr++ = '"';
+               ptr = acl_safe_strcopy( ptr, " sockurl" );
+               ptr = acl_safe_strcopy( ptr, "." );
+               ptr = acl_safe_strcopy( ptr, style_strings[b->a_sockurl_style] );
+               ptr = acl_safe_strcopy( ptr, "=\"" );
+               ptr = acl_safe_strbvcopy( ptr, &b->a_sockurl_pat );
+               ptr = acl_safe_strcopy( ptr, "\"" );
        }
 
        if ( !BER_BVISEMPTY( &b->a_set_pat ) ) {
-               ptr = lutil_strcopy( ptr, " set" );
-               *ptr++ = '.';
-               ptr = lutil_strcopy( ptr, style_strings[b->a_set_style] );
-               *ptr++ = '=';
-               *ptr++ = '"';
-               ptr = lutil_strcopy( ptr, b->a_set_pat.bv_val );
-               *ptr++ = '"';
+               ptr = acl_safe_strcopy( ptr, " set" );
+               ptr = acl_safe_strcopy( ptr, "." );
+               ptr = acl_safe_strcopy( ptr, style_strings[b->a_set_style] );
+               ptr = acl_safe_strcopy( ptr, "=\"" );
+               ptr = acl_safe_strbvcopy( ptr, &b->a_set_pat );
+               ptr = acl_safe_strcopy( ptr, "\"" );
        }
 
 #ifdef SLAP_DYNACL
@@ -2678,7 +2712,7 @@ access2text( Access *b, char *ptr )
                                struct berval bv = BER_BVNULL;
                                (void)( *da->da_unparse )( da->da_private, &bv );
                                assert( !BER_BVISNULL( &bv ) );
-                               ptr = lutil_strcopy( ptr, bv.bv_val );
+                               ptr = acl_safe_strbvcopy( ptr, &bv );
                                ch_free( bv.bv_val );
                        }
                }
@@ -2687,43 +2721,51 @@ access2text( Access *b, char *ptr )
 
        /* Security Strength Factors */
        if ( b->a_authz.sai_ssf ) {
-               ptr += sprintf( ptr, " ssf=%u", 
+               char buf[SLAP_TEXT_BUFLEN];
+               int n = snprintf( buf, sizeof(buf), " ssf=%u", 
                        b->a_authz.sai_ssf );
+               ptr = acl_safe_strncopy( ptr, buf, n );
        }
        if ( b->a_authz.sai_transport_ssf ) {
-               ptr += sprintf( ptr, " transport_ssf=%u",
+               char buf[SLAP_TEXT_BUFLEN];
+               int n = snprintf( buf, sizeof(buf), " transport_ssf=%u",
                        b->a_authz.sai_transport_ssf );
+               ptr = acl_safe_strncopy( ptr, buf, n );
        }
        if ( b->a_authz.sai_tls_ssf ) {
-               ptr += sprintf( ptr, " tls_ssf=%u",
+               char buf[SLAP_TEXT_BUFLEN];
+               int n = snprintf( buf, sizeof(buf), " tls_ssf=%u",
                        b->a_authz.sai_tls_ssf );
+               ptr = acl_safe_strncopy( ptr, buf, n );
        }
        if ( b->a_authz.sai_sasl_ssf ) {
-               ptr += sprintf( ptr, " sasl_ssf=%u",
+               char buf[SLAP_TEXT_BUFLEN];
+               int n = snprintf( buf, sizeof(buf), " sasl_ssf=%u",
                        b->a_authz.sai_sasl_ssf );
+               ptr = acl_safe_strncopy( ptr, buf, n );
        }
 
-       *ptr++ = ' ';
+       ptr = acl_safe_strcopy( ptr, " " );
        if ( b->a_dn_self ) {
-               ptr = lutil_strcopy( ptr, "self" );
+               ptr = acl_safe_strcopy( ptr, "self" );
        } else if ( b->a_realdn_self ) {
-               ptr = lutil_strcopy( ptr, "realself" );
+               ptr = acl_safe_strcopy( ptr, "realself" );
        }
-       ptr = lutil_strcopy( ptr, accessmask2str( b->a_access_mask, maskbuf, 0 ));
+       ptr = acl_safe_strcopy( ptr, accessmask2str( b->a_access_mask, maskbuf, 0 ));
        if ( !maskbuf[0] ) ptr--;
 
        if( b->a_type == ACL_BREAK ) {
-               ptr = lutil_strcopy( ptr, " break" );
+               ptr = acl_safe_strcopy( ptr, " break" );
 
        } else if( b->a_type == ACL_CONTINUE ) {
-               ptr = lutil_strcopy( ptr, " continue" );
+               ptr = acl_safe_strcopy( ptr, " continue" );
 
        } else if( b->a_type != ACL_STOP ) {
-               ptr = lutil_strcopy( ptr, " unknown-control" );
+               ptr = acl_safe_strcopy( ptr, " unknown-control" );
        } else {
-               if ( !maskbuf[0] ) ptr = lutil_strcopy( ptr, " stop" );
+               if ( !maskbuf[0] ) ptr = acl_safe_strcopy( ptr, " stop" );
        }
-       *ptr++ = '\n';
+       ptr = acl_safe_strcopy( ptr, "\n" );
 
        return ptr;
 }
@@ -2735,35 +2777,38 @@ acl_unparse( AccessControl *a, struct berval *bv )
        char    *ptr;
        int     to = 0;
 
-       bv->bv_val = aclbuf;
+       if ( BER_BVISNULL( &aclbuf ) ) {
+               aclbuf.bv_val = ch_malloc( ACLBUF_CHUNKSIZE );
+               aclbuf.bv_len = ACLBUF_CHUNKSIZE;
+       }
+
+       bv->bv_val = aclbuf.bv_val;
        bv->bv_len = 0;
 
        ptr = bv->bv_val;
 
-       ptr = lutil_strcopy( ptr, "to" );
+       ptr = acl_safe_strcopy( ptr, "to" );
        if ( !BER_BVISNULL( &a->acl_dn_pat ) ) {
                to++;
-               ptr = lutil_strcopy( ptr, " dn." );
+               ptr = acl_safe_strcopy( ptr, " dn." );
                if ( a->acl_dn_style == ACL_STYLE_BASE )
-                       ptr = lutil_strcopy( ptr, style_base );
+                       ptr = acl_safe_strcopy( ptr, style_base );
                else
-                       ptr = lutil_strcopy( ptr, style_strings[a->acl_dn_style] );
-               *ptr++ = '=';
-               *ptr++ = '"';
-               ptr = lutil_strcopy( ptr, a->acl_dn_pat.bv_val );
-               ptr = lutil_strcopy( ptr, "\"\n" );
+                       ptr = acl_safe_strcopy( ptr, style_strings[a->acl_dn_style] );
+               ptr = acl_safe_strcopy( ptr, "=\"" );
+               ptr = acl_safe_strbvcopy( ptr, &a->acl_dn_pat );
+               ptr = acl_safe_strcopy( ptr, "\"\n" );
        }
 
        if ( a->acl_filter != NULL ) {
-               struct berval   bv = BER_BVNULL;
+               struct berval   fbv = BER_BVNULL;
 
                to++;
-               filter2bv( a->acl_filter, &bv );
-               ptr = lutil_strcopy( ptr, " filter=\"" );
-               ptr = lutil_strcopy( ptr, bv.bv_val );
-               *ptr++ = '"';
-               *ptr++ = '\n';
-               ch_free( bv.bv_val );
+               filter2bv( a->acl_filter, &fbv );
+               ptr = acl_safe_strcopy( ptr, " filter=\"" );
+               ptr = acl_safe_strbvcopy( ptr, &fbv );
+               ptr = acl_safe_strcopy( ptr, "\"\n" );
+               ch_free( fbv.bv_val );
        }
 
        if ( a->acl_attrs != NULL ) {
@@ -2771,39 +2816,37 @@ acl_unparse( AccessControl *a, struct berval *bv )
                AttributeName *an;
                to++;
 
-               ptr = lutil_strcopy( ptr, " attrs=" );
+               ptr = acl_safe_strcopy( ptr, " attrs=" );
                for ( an = a->acl_attrs; an && !BER_BVISNULL( &an->an_name ); an++ ) {
-                       if ( ! first ) *ptr++ = ',';
+                       if ( ! first ) ptr = acl_safe_strcopy( ptr, ",");
                        if (an->an_oc) {
-                               *ptr++ = ( an->an_flags & SLAP_AN_OCEXCLUDE ) ? '!' : '@';
-                               ptr = lutil_strcopy( ptr, an->an_oc->soc_cname.bv_val );
+                               ptr = acl_safe_strcopy( ptr, ( an->an_flags & SLAP_AN_OCEXCLUDE ) ? "!" : "@" );
+                               ptr = acl_safe_strbvcopy( ptr, &an->an_oc->soc_cname );
 
                        } else {
-                               ptr = lutil_strcopy( ptr, an->an_name.bv_val );
+                               ptr = acl_safe_strbvcopy( ptr, &an->an_name );
                        }
                        first = 0;
                }
-               *ptr++ = '\n';
+               ptr = acl_safe_strcopy( ptr, "\n" );
        }
 
        if ( !BER_BVISEMPTY( &a->acl_attrval ) ) {
                to++;
-               ptr = lutil_strcopy( ptr, " val." );
+               ptr = acl_safe_strcopy( ptr, " val." );
                if ( a->acl_attrval_style == ACL_STYLE_BASE &&
                        a->acl_attrs[0].an_desc->ad_type->sat_syntax ==
                                slap_schema.si_syn_distinguishedName )
-                       ptr = lutil_strcopy( ptr, style_base );
+                       ptr = acl_safe_strcopy( ptr, style_base );
                else
-                       ptr = lutil_strcopy( ptr, style_strings[a->acl_attrval_style] );
-               *ptr++ = '=';
-               *ptr++ = '"';
-               ptr = lutil_strcopy( ptr, a->acl_attrval.bv_val );
-               *ptr++ = '"';
-               *ptr++ = '\n';
+                       ptr = acl_safe_strcopy( ptr, style_strings[a->acl_attrval_style] );
+               ptr = acl_safe_strcopy( ptr, "=\"" );
+               ptr = acl_safe_strbvcopy( ptr, &a->acl_attrval );
+               ptr = acl_safe_strcopy( ptr, "\"\n" );
        }
 
-       if( !to ) {
-               ptr = lutil_strcopy( ptr, " *\n" );
+       if ( !to ) {
+               ptr = acl_safe_strcopy( ptr, " *\n" );
        }
 
        for ( b = a->acl_access; b != NULL; b = b->a_next ) {