openldap/libraries/liblber/encode.c
Quanah Gibson-Mount 1df85d3427 Happy New Year!
2017-01-03 12:36:47 -08:00

652 lines
15 KiB
C

/* encode.c - ber output encoding routines */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 1998-2017 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) 1990 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.
*/
/* ACKNOWLEDGEMENTS:
* This work was originally developed by the University of Michigan
* (as part of U-MICH LDAP).
*/
#include "portable.h"
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <ac/stdlib.h>
#include <ac/stdarg.h>
#include <ac/socket.h>
#include <ac/string.h>
#include "lber-int.h"
#define OCTET_SIZE(type) ((ber_len_t) (sizeof(type)*CHAR_BIT + 7) / 8)
#define TAGBUF_SIZE OCTET_SIZE(ber_tag_t)
#define LENBUF_SIZE (1 + OCTET_SIZE(ber_len_t))
#define HEADER_SIZE (TAGBUF_SIZE + LENBUF_SIZE)
/*
* BER element size constrains:
*
* - We traditionally support a length of max 0xffffffff. However
* some functions return an int length so that is their max.
* MAXINT_BERSIZE is the max for those functions.
*
* - MAXINT_BERSIZE must fit in MAXINT_BERSIZE_OCTETS octets.
*
* - sizeof(ber_elem_size_t) is normally MAXINT_BERSIZE_OCTETS:
* Big enough for MAXINT_BERSIZE, but not more. (Larger wastes
* space in the working encoding and DER encoding of a sequence
* or set. Smaller further limits sizes near a sequence/set.)
*
* ber_len_t is mostly unrelated to this. Which may be for the best,
* since it is also used for lengths of data that are never encoded.
*/
#define MAXINT_BERSIZE \
(INT_MAX>0xffffffffUL ? (ber_len_t) 0xffffffffUL : INT_MAX-HEADER_SIZE)
#define MAXINT_BERSIZE_OCTETS 4
typedef ber_uint_t ber_elem_size_t; /* normally 32 bits */
/* Prepend tag to ptr, which points to the end of a tag buffer */
static unsigned char *
ber_prepend_tag( unsigned char *ptr, ber_tag_t tag )
{
do {
*--ptr = (unsigned char) tag & 0xffU;
} while ( (tag >>= 8) != 0 );
return ptr;
}
/* Prepend ber length to ptr, which points to the end of a length buffer */
static unsigned char *
ber_prepend_len( unsigned char *ptr, ber_len_t len )
{
/*
* short len if it's less than 128 - one byte giving the len,
* with bit 8 0.
* long len otherwise - one byte with bit 8 set, giving the
* length of the length, followed by the length itself.
*/
*--ptr = (unsigned char) len & 0xffU;
if ( len >= 0x80 ) {
unsigned char *endptr = ptr--;
while ( (len >>= 8) != 0 ) {
*ptr-- = (unsigned char) len & 0xffU;
}
*ptr = (unsigned char) (endptr - ptr) + 0x80U;
}
return ptr;
}
/* out->bv_len should be the buffer size on input */
int
ber_encode_oid( BerValue *in, BerValue *out )
{
unsigned char *der;
unsigned long val1, val;
int i, j, len;
char *ptr, *end, *inend;
assert( in != NULL );
assert( out != NULL );
if ( !out->bv_val || out->bv_len < in->bv_len/2 )
return -1;
der = (unsigned char *) out->bv_val;
ptr = in->bv_val;
inend = ptr + in->bv_len;
/* OIDs start with <0-1>.<0-39> or 2.<any>, DER-encoded 40*val1+val2 */
if ( !isdigit( (unsigned char) *ptr )) return -1;
val1 = strtoul( ptr, &end, 10 );
if ( end == ptr || val1 > 2 ) return -1;
if ( *end++ != '.' || !isdigit( (unsigned char) *end )) return -1;
val = strtoul( end, &ptr, 10 );
if ( ptr == end ) return -1;
if ( val > (val1 < 2 ? 39 : LBER_OID_COMPONENT_MAX - 80) ) return -1;
val += val1 * 40;
for (;;) {
if ( ptr > inend ) return -1;
/* Write the OID component little-endian, then reverse it */
len = 0;
do {
der[len++] = (val & 0xff) | 0x80;
} while ( (val >>= 7) != 0 );
der[0] &= 0x7f;
for ( i = 0, j = len; i < --j; i++ ) {
unsigned char tmp = der[i];
der[i] = der[j];
der[j] = tmp;
}
der += len;
if ( ptr == inend )
break;
if ( *ptr++ != '.' ) return -1;
if ( !isdigit( (unsigned char) *ptr )) return -1;
val = strtoul( ptr, &end, 10 );
if ( end == ptr || val > LBER_OID_COMPONENT_MAX ) return -1;
ptr = end;
}
out->bv_len = (char *)der - out->bv_val;
return 0;
}
static int
ber_put_int_or_enum(
BerElement *ber,
ber_int_t num,
ber_tag_t tag )
{
ber_uint_t unum;
unsigned char sign, data[TAGBUF_SIZE+1 + OCTET_SIZE(ber_int_t)], *ptr;
sign = 0;
unum = num; /* Bit fiddling should be done with unsigned values */
if ( num < 0 ) {
sign = 0xffU;
unum = ~unum;
}
for ( ptr = &data[sizeof(data) - 1] ;; unum >>= 8 ) {
*ptr-- = (sign ^ (unsigned char) unum) & 0xffU;
if ( unum < 0x80 ) /* top bit at *ptr is sign bit */
break;
}
*ptr = (unsigned char) (&data[sizeof(data) - 1] - ptr); /* length */
ptr = ber_prepend_tag( ptr, tag );
return ber_write( ber, (char *) ptr, &data[sizeof(data)] - ptr, 0 );
}
int
ber_put_enum(
BerElement *ber,
ber_int_t num,
ber_tag_t tag )
{
if ( tag == LBER_DEFAULT ) {
tag = LBER_ENUMERATED;
}
return ber_put_int_or_enum( ber, num, tag );
}
int
ber_put_int(
BerElement *ber,
ber_int_t num,
ber_tag_t tag )
{
if ( tag == LBER_DEFAULT ) {
tag = LBER_INTEGER;
}
return ber_put_int_or_enum( ber, num, tag );
}
int
ber_put_ostring(
BerElement *ber,
LDAP_CONST char *str,
ber_len_t len,
ber_tag_t tag )
{
int rc;
unsigned char header[HEADER_SIZE], *ptr;
if ( tag == LBER_DEFAULT ) {
tag = LBER_OCTETSTRING;
}
if ( len > MAXINT_BERSIZE ) {
return -1;
}
ptr = ber_prepend_len( &header[sizeof(header)], len );
ptr = ber_prepend_tag( ptr, tag );
rc = ber_write( ber, (char *) ptr, &header[sizeof(header)] - ptr, 0 );
if ( rc >= 0 && ber_write( ber, str, len, 0 ) >= 0 ) {
/* length(tag + length + contents) */
return rc + (int) len;
}
return -1;
}
int
ber_put_berval(
BerElement *ber,
struct berval *bv,
ber_tag_t tag )
{
if( bv == NULL || bv->bv_len == 0 ) {
return ber_put_ostring( ber, "", (ber_len_t) 0, tag );
}
return ber_put_ostring( ber, bv->bv_val, bv->bv_len, tag );
}
int
ber_put_string(
BerElement *ber,
LDAP_CONST char *str,
ber_tag_t tag )
{
assert( str != NULL );
return ber_put_ostring( ber, str, strlen( str ), tag );
}
int
ber_put_bitstring(
BerElement *ber,
LDAP_CONST char *str,
ber_len_t blen /* in bits */,
ber_tag_t tag )
{
int rc;
ber_len_t len;
unsigned char unusedbits, header[HEADER_SIZE + 1], *ptr;
if ( tag == LBER_DEFAULT ) {
tag = LBER_BITSTRING;
}
unusedbits = (unsigned char) -blen & 7;
len = blen / 8 + (unusedbits != 0); /* (blen+7)/8 without overflow */
if ( len >= MAXINT_BERSIZE ) {
return -1;
}
header[sizeof(header) - 1] = unusedbits;
ptr = ber_prepend_len( &header[sizeof(header) - 1], len + 1 );
ptr = ber_prepend_tag( ptr, tag );
rc = ber_write( ber, (char *) ptr, &header[sizeof(header)] - ptr, 0 );
if ( rc >= 0 && ber_write( ber, str, len, 0 ) >= 0 ) {
/* length(tag + length + unused bit count + bitstring) */
return rc + (int) len;
}
return -1;
}
int
ber_put_null( BerElement *ber, ber_tag_t tag )
{
unsigned char data[TAGBUF_SIZE + 1], *ptr;
if ( tag == LBER_DEFAULT ) {
tag = LBER_NULL;
}
data[sizeof(data) - 1] = 0; /* length */
ptr = ber_prepend_tag( &data[sizeof(data) - 1], tag );
return ber_write( ber, (char *) ptr, &data[sizeof(data)] - ptr, 0 );
}
int
ber_put_boolean(
BerElement *ber,
ber_int_t boolval,
ber_tag_t tag )
{
unsigned char data[TAGBUF_SIZE + 2], *ptr;
if ( tag == LBER_DEFAULT )
tag = LBER_BOOLEAN;
data[sizeof(data) - 1] = boolval ? 0xff : 0;
data[sizeof(data) - 2] = 1; /* length */
ptr = ber_prepend_tag( &data[sizeof(data) - 2], tag );
return ber_write( ber, (char *) ptr, &data[sizeof(data)] - ptr, 0 );
}
/* Max number of length octets in a sequence or set, normally 5 */
#define SOS_LENLEN (1 + (sizeof(ber_elem_size_t) > MAXINT_BERSIZE_OCTETS ? \
(ber_len_t) sizeof(ber_elem_size_t) : MAXINT_BERSIZE_OCTETS))
/* Header of incomplete sequence or set */
typedef struct seqorset_header {
char xtagbuf[TAGBUF_SIZE + 1]; /* room for tag + len(tag or len) */
union {
ber_elem_size_t offset; /* enclosing seqence/set */
char padding[SOS_LENLEN-1]; /* for final length encoding */
} next_sos;
# define SOS_TAG_END(header) ((unsigned char *) &(header).next_sos - 1)
} Seqorset_header;
/* Start a sequence or set */
static int
ber_start_seqorset(
BerElement *ber,
ber_tag_t tag )
{
/*
* Write the tag and SOS_LENLEN octets reserved for length, to ber.
* For now, length octets = (tag length, previous ber_sos_inner).
*
* Update ber_sos_inner and the write-cursor ber_sos_ptr. ber_ptr
* will not move until the outermost sequence or set is complete.
*/
Seqorset_header header;
unsigned char *headptr;
ber_len_t taglen, headlen;
char *dest, **p;
assert( ber != NULL );
assert( LBER_VALID( ber ) );
if ( ber->ber_sos_ptr == NULL ) { /* outermost sequence/set? */
header.next_sos.offset = 0;
p = &ber->ber_ptr;
} else {
if ( (ber_len_t) -1 > (ber_elem_size_t) -1 ) {
if ( ber->ber_sos_inner > (ber_elem_size_t) -1 )
return -1;
}
header.next_sos.offset = ber->ber_sos_inner;
p = &ber->ber_sos_ptr;
}
headptr = ber_prepend_tag( SOS_TAG_END(header), tag );
*SOS_TAG_END(header) = taglen = SOS_TAG_END(header) - headptr;
headlen = taglen + SOS_LENLEN;
/* As ber_write(,headptr,headlen,) except update ber_sos_ptr, not *p */
if ( headlen > (ber_len_t) (ber->ber_end - *p) ) {
if ( ber_realloc( ber, headlen ) != 0 )
return -1;
}
dest = *p;
AC_MEMCPY( dest, headptr, headlen );
ber->ber_sos_ptr = dest + headlen;
ber->ber_sos_inner = dest + taglen - ber->ber_buf;
/*
* Do not return taglen + SOS_LENLEN here - then ber_put_seqorset()
* should return lenlen - SOS_LENLEN + len, which can be < 0.
*/
return 0;
}
int
ber_start_seq( BerElement *ber, ber_tag_t tag )
{
if ( tag == LBER_DEFAULT ) {
tag = LBER_SEQUENCE;
}
return ber_start_seqorset( ber, tag );
}
int
ber_start_set( BerElement *ber, ber_tag_t tag )
{
if ( tag == LBER_DEFAULT ) {
tag = LBER_SET;
}
return ber_start_seqorset( ber, tag );
}
/* End a sequence or set */
static int
ber_put_seqorset( BerElement *ber )
{
Seqorset_header header;
unsigned char *lenptr; /* length octets in the sequence/set */
ber_len_t len; /* length(contents) */
ber_len_t xlen; /* len + length(length) */
assert( ber != NULL );
assert( LBER_VALID( ber ) );
if ( ber->ber_sos_ptr == NULL ) return -1;
lenptr = (unsigned char *) ber->ber_buf + ber->ber_sos_inner;
xlen = ber->ber_sos_ptr - (char *) lenptr;
if ( xlen > MAXINT_BERSIZE + SOS_LENLEN ) {
return -1;
}
/* Extract sequence/set information from length octets */
memcpy( SOS_TAG_END(header), lenptr, SOS_LENLEN );
/* Store length, and close gap of leftover reserved length octets */
len = xlen - SOS_LENLEN;
if ( !(ber->ber_options & LBER_USE_DER) ) {
int i;
lenptr[0] = SOS_LENLEN - 1 + 0x80; /* length(length)-1 */
for( i = SOS_LENLEN; --i > 0; len >>= 8 ) {
lenptr[i] = len & 0xffU;
}
} else {
unsigned char *p = ber_prepend_len( lenptr + SOS_LENLEN, len );
ber_len_t unused = p - lenptr;
if ( unused != 0 ) {
/* length(length) < the reserved SOS_LENLEN bytes */
xlen -= unused;
AC_MEMCPY( lenptr, p, xlen );
ber->ber_sos_ptr = (char *) lenptr + xlen;
}
}
ber->ber_sos_inner = header.next_sos.offset;
if ( header.next_sos.offset == 0 ) { /* outermost sequence/set? */
/* The ber_ptr is at the set/seq start - move it to the end */
ber->ber_ptr = ber->ber_sos_ptr;
ber->ber_sos_ptr = NULL;
}
return xlen + *SOS_TAG_END(header); /* lenlen + len + taglen */
}
int
ber_put_seq( BerElement *ber )
{
return ber_put_seqorset( ber );
}
int
ber_put_set( BerElement *ber )
{
return ber_put_seqorset( ber );
}
/* N tag */
static ber_tag_t lber_int_null = 0;
/* VARARGS */
int
ber_printf( BerElement *ber, LDAP_CONST char *fmt, ... )
{
va_list ap;
char *s, **ss;
struct berval *bv, **bvp;
int rc;
ber_int_t i;
ber_len_t len;
assert( ber != NULL );
assert( fmt != NULL );
assert( LBER_VALID( ber ) );
va_start( ap, fmt );
for ( rc = 0; *fmt && rc != -1; fmt++ ) {
switch ( *fmt ) {
case '!': { /* hook */
BEREncodeCallback *f;
void *p;
ber->ber_usertag = 0;
f = va_arg( ap, BEREncodeCallback * );
p = va_arg( ap, void * );
rc = (*f)( ber, p );
if ( ber->ber_usertag ) {
goto next;
}
} break;
case 'b': /* boolean */
i = va_arg( ap, ber_int_t );
rc = ber_put_boolean( ber, i, ber->ber_tag );
break;
case 'i': /* int */
i = va_arg( ap, ber_int_t );
rc = ber_put_int( ber, i, ber->ber_tag );
break;
case 'e': /* enumeration */
i = va_arg( ap, ber_int_t );
rc = ber_put_enum( ber, i, ber->ber_tag );
break;
case 'n': /* null */
rc = ber_put_null( ber, ber->ber_tag );
break;
case 'N': /* Debug NULL */
rc = 0;
if( lber_int_null != 0 ) {
/* Insert NULL to ensure peer ignores unknown tags */
rc = ber_put_null( ber, lber_int_null );
}
break;
case 'o': /* octet string (non-null terminated) */
s = va_arg( ap, char * );
len = va_arg( ap, ber_len_t );
rc = ber_put_ostring( ber, s, len, ber->ber_tag );
break;
case 'O': /* berval octet string */
bv = va_arg( ap, struct berval * );
if( bv == NULL ) break;
rc = ber_put_berval( ber, bv, ber->ber_tag );
break;
case 's': /* string */
s = va_arg( ap, char * );
rc = ber_put_string( ber, s, ber->ber_tag );
break;
case 'B': /* bit string */
case 'X': /* bit string (deprecated) */
s = va_arg( ap, char * );
len = va_arg( ap, ber_len_t ); /* in bits */
rc = ber_put_bitstring( ber, s, len, ber->ber_tag );
break;
case 't': /* tag for the next element */
ber->ber_tag = va_arg( ap, ber_tag_t );
goto next;
case 'v': /* vector of strings */
if ( (ss = va_arg( ap, char ** )) == NULL )
break;
for ( i = 0; ss[i] != NULL; i++ ) {
if ( (rc = ber_put_string( ber, ss[i],
ber->ber_tag )) == -1 )
break;
}
break;
case 'V': /* sequences of strings + lengths */
if ( (bvp = va_arg( ap, struct berval ** )) == NULL )
break;
for ( i = 0; bvp[i] != NULL; i++ ) {
if ( (rc = ber_put_berval( ber, bvp[i],
ber->ber_tag )) == -1 )
break;
}
break;
case 'W': /* BerVarray */
if ( (bv = va_arg( ap, BerVarray )) == NULL )
break;
for ( i = 0; bv[i].bv_val != NULL; i++ ) {
if ( (rc = ber_put_berval( ber, &bv[i],
ber->ber_tag )) == -1 )
break;
}
break;
case '{': /* begin sequence */
rc = ber_start_seq( ber, ber->ber_tag );
break;
case '}': /* end sequence */
rc = ber_put_seqorset( ber );
break;
case '[': /* begin set */
rc = ber_start_set( ber, ber->ber_tag );
break;
case ']': /* end set */
rc = ber_put_seqorset( ber );
break;
default:
if( ber->ber_debug ) {
ber_log_printf( LDAP_DEBUG_ANY, ber->ber_debug,
"ber_printf: unknown fmt %c\n", *fmt );
}
rc = -1;
break;
}
ber->ber_tag = LBER_DEFAULT;
next:;
}
va_end( ap );
return rc;
}