xref: /illumos-gate/usr/src/lib/libldap5/sources/ldap/ber/encode.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /*
2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
7  *
8  * The contents of this file are subject to the Netscape Public License
9  * Version 1.0 (the "NPL"); you may not use this file except in
10  * compliance with the NPL.  You may obtain a copy of the NPL at
11  * http://www.mozilla.org/NPL/
12  *
13  * Software distributed under the NPL is distributed on an "AS IS" basis,
14  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
15  * for the specific language governing rights and limitations under the
16  * NPL.
17  *
18  * The Initial Developer of this code under the NPL is Netscape
19  * Communications Corporation.  Portions created by Netscape are
20  * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
21  * Reserved.
22  */
23 
24 /*
25  * Copyright (c) 1990 Regents of the University of Michigan.
26  * All rights reserved.
27  *
28  * Redistribution and use in source and binary forms are permitted
29  * provided that this notice is preserved and that due credit is given
30  * to the University of Michigan at Ann Arbor. The name of the University
31  * may not be used to endorse or promote products derived from this
32  * software without specific prior written permission. This software
33  * is provided ``as is'' without express or implied warranty.
34  */
35 
36 /* encode.c - ber output encoding routines */
37 
38 #include "lber-int.h"
39 
40 /* the following constants are used in ber_calc_lenlen */
41 
42 #define LENMASK1	0xFF
43 #define	LENMASK2 	0xFFFF
44 #define LENMASK3	0xFFFFFF
45 #define LENMASK4	0xFFFFFFFF
46 #define _MASK		0x80
47 
48 static int
49 ber_calc_taglen( ber_tag_t tag )
50 {
51 	int		i;
52 	ber_int_t	mask;
53 
54 	/* find the first non-all-zero byte in the tag */
55 	for ( i = sizeof(ber_int_t) - 1; i > 0; i-- ) {
56 		mask = (LENMASK3 << (i * 8));
57 		/* not all zero */
58 		if ( tag & mask )
59 			break;
60 	}
61 
62 	return( i + 1 );
63 }
64 
65 static int
66 ber_put_tag( BerElement	*ber, ber_tag_t tag, int nosos )
67 {
68 	int		taglen;
69 	ber_tag_t	ntag;
70 
71 	taglen = ber_calc_taglen( tag );
72 
73 	ntag = LBER_HTONL( tag );
74 
75 	return( ber_write( ber, ((char *) &ntag) + sizeof(ber_int_t) - taglen,
76 	    taglen, nosos ) );
77 }
78 
79 static int
80 ber_calc_lenlen( ber_len_t len )
81 {
82 	/*
83 	 * short len if it's less than 128 - one byte giving the len,
84 	 * with bit 8 0.
85 	 */
86 
87 	if ( len <= 0x7F )
88 		return( 1 );
89 
90 	/*
91 	 * long len otherwise - one byte with bit 8 set, giving the
92 	 * length of the length, followed by the length itself.
93 	 */
94 
95 	if ( len <= LENMASK1 )
96 		return( 2 );
97 	if ( len <= LENMASK2 )
98 		return( 3 );
99 	if ( len <= LENMASK3 )
100 		return( 4 );
101 
102 	return( 5 );
103 }
104 
105 static int
106 ber_put_len( BerElement *ber, ber_len_t len, int nosos )
107 {
108 	int		i;
109 	char		lenlen;
110 	ber_int_t	mask;
111 	ber_len_t	netlen;
112 
113 	/*
114 	 * short len if it's less than 128 - one byte giving the len,
115 	 * with bit 8 0.
116 	 */
117 
118 	if ( len <= 127 ) {
119 		netlen = LBER_HTONL( len );
120 		return( ber_write( ber, (char *) &netlen + sizeof(ber_int_t) - 1,
121 		    1, nosos ) );
122 	}
123 
124 	/*
125 	 * long len otherwise - one byte with bit 8 set, giving the
126 	 * length of the length, followed by the length itself.
127 	 */
128 
129 	/* find the first non-all-zero byte */
130 	for ( i = sizeof(ber_int_t) - 1; i > 0; i-- ) {
131 		mask = (LENMASK1 << (i * 8));
132 		/* not all zero */
133 		if ( len & mask )
134 			break;
135 	}
136 	lenlen = ++i;
137 	if ( lenlen > 4 )
138 		return( -1 );
139 	lenlen |= 0x80;
140 
141 	/* write the length of the length */
142 	if ( ber_write( ber, &lenlen, 1, nosos ) != 1 )
143 		return( -1 );
144 
145 	/* write the length itself */
146 	netlen = LBER_HTONL( len );
147 	if ( ber_write( ber, (char *) &netlen + (sizeof(ber_int_t) - i), i, nosos )
148 	    != i )
149 		return( -1 );
150 
151 	return( i + 1 );
152 }
153 
154 static int
155 ber_put_int_or_enum( BerElement *ber, ber_int_t num, ber_tag_t tag )
156 {
157 	int		i, sign, taglen;
158 	int		len, lenlen;
159 	ber_int_t	netnum, mask;
160 
161 	sign = (num < 0);
162 
163 	/*
164 	 * high bit is set - look for first non-all-one byte
165 	 * high bit is clear - look for first non-all-zero byte
166 	 */
167 	for ( i = sizeof(ber_int_t) - 1; i > 0; i-- ) {
168 		mask = (LENMASK1 << (i * 8));
169 
170 		if ( sign ) {
171 			/* not all ones */
172 			if ( (num & mask) != mask )
173 				break;
174 		} else {
175 			/* not all zero */
176 			if ( num & mask )
177 				break;
178 		}
179 	}
180 
181 	/*
182 	 * we now have the "leading byte".  if the high bit on this
183 	 * byte matches the sign bit, we need to "back up" a byte.
184 	 */
185 	mask = (num & (_MASK << (i * 8)));
186 	if ( (mask && !sign) || (sign && !mask) )
187 		i++;
188 
189 	len = i + 1;
190 
191 	if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
192 		return( -1 );
193 
194 	if ( (lenlen = ber_put_len( ber, len, 0 )) == -1 )
195 		return( -1 );
196 	i++;
197 	netnum = LBER_HTONL( num );
198 	if ( ber_write( ber, (char *) &netnum + (sizeof(ber_int_t) - i), i, 0 )
199 		== i)
200 		/* length of tag + length + contents */
201 		return( taglen + lenlen + i );
202 
203 	return( -1 );
204 }
205 
206 int
207 LDAP_CALL
208 ber_put_enum( BerElement *ber, ber_int_t num, ber_tag_t tag )
209 {
210 	if ( tag == LBER_DEFAULT )
211 		tag = LBER_ENUMERATED;
212 
213 	return( ber_put_int_or_enum( ber, num, tag ) );
214 }
215 
216 int
217 LDAP_CALL
218 ber_put_int( BerElement *ber, ber_int_t num, ber_tag_t tag )
219 {
220 	if ( tag == LBER_DEFAULT )
221 		tag = LBER_INTEGER;
222 
223 	return( ber_put_int_or_enum( ber, num, tag ) );
224 }
225 
226 int
227 LDAP_CALL
228 ber_put_ostring( BerElement *ber, char *str, ber_len_t len,
229 	ber_tag_t tag )
230 {
231 	int	taglen, lenlen, rc;
232 #ifdef STR_TRANSLATION
233 	int	free_str;
234 #endif /* STR_TRANSLATION */
235 
236 	if ( tag == LBER_DEFAULT )
237 		tag = LBER_OCTETSTRING;
238 
239 	if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
240 		return( -1 );
241 
242 #ifdef STR_TRANSLATION
243 	if ( len > 0 && ( ber->ber_options & LBER_OPT_TRANSLATE_STRINGS ) != 0
244 	    && ber->ber_encode_translate_proc != NULL ) {
245 		if ( (*(ber->ber_encode_translate_proc))( &str, &len, 0 )
246 		    != 0 ) {
247 			return( -1 );
248 		}
249 		free_str = 1;
250 	} else {
251 		free_str = 0;
252 	}
253 #endif /* STR_TRANSLATION */
254 
255     /*
256      *  Note:  below is a spot where we limit ber_write
257      *         to signed long (instead of unsigned long)
258      */
259 
260 	if ( (lenlen = ber_put_len( ber, len, 0 )) == -1 ||
261 		ber_write( ber, str, len, 0 ) != (ber_int_t) len ) {
262 		rc = -1;
263 	} else {
264 		/* return length of tag + length + contents */
265 		rc = taglen + lenlen + len;
266 	}
267 
268 #ifdef STR_TRANSLATION
269 	if ( free_str ) {
270 		NSLBERI_FREE( str );
271 	}
272 #endif /* STR_TRANSLATION */
273 
274 	return( rc );
275 }
276 
277 int
278 LDAP_CALL
279 ber_put_string( BerElement *ber, char *str, ber_tag_t tag )
280 {
281 	return( ber_put_ostring( ber, str, (ber_len_t) strlen( str ), tag ));
282 }
283 
284 int
285 LDAP_CALL
286 ber_put_bitstring( BerElement *ber, char *str,
287 	ber_len_t blen /* in bits */, ber_tag_t tag )
288 {
289 	int		taglen, lenlen, len;
290 	unsigned char	unusedbits;
291 
292 	if ( tag == LBER_DEFAULT )
293 		tag = LBER_BITSTRING;
294 
295 	if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
296 		return( -1 );
297 
298 	len = ( blen + 7 ) / 8;
299 	unusedbits = (unsigned char) (len * 8 - blen);
300 	if ( (lenlen = ber_put_len( ber, len + 1, 0 )) == -1 )
301 		return( -1 );
302 
303 	if ( ber_write( ber, (char *)&unusedbits, 1, 0 ) != 1 )
304 		return( -1 );
305 
306 	if ( ber_write( ber, str, len, 0 ) != len )
307 		return( -1 );
308 
309 	/* return length of tag + length + unused bit count + contents */
310 	return( taglen + 1 + lenlen + len );
311 }
312 
313 int
314 LDAP_CALL
315 ber_put_null( BerElement *ber, ber_tag_t tag )
316 {
317 	int	taglen;
318 
319 	if ( tag == LBER_DEFAULT )
320 		tag = LBER_NULL;
321 
322 	if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
323 		return( -1 );
324 
325 	if ( ber_put_len( ber, 0, 0 ) != 1 )
326 		return( -1 );
327 
328 	return( taglen + 1 );
329 }
330 
331 int
332 LDAP_CALL
333 ber_put_boolean( BerElement *ber, int boolval, ber_tag_t tag )
334 {
335 	int		taglen;
336 	unsigned char	trueval = 0xff;
337 	unsigned char	falseval = 0x00;
338 
339 	if ( tag == LBER_DEFAULT )
340 		tag = LBER_BOOLEAN;
341 
342 	if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
343 		return( -1 );
344 
345 	if ( ber_put_len( ber, 1, 0 ) != 1 )
346 		return( -1 );
347 
348 	if ( ber_write( ber, (char *)(boolval ? &trueval : &falseval), 1, 0 )
349 	    != 1 )
350 		return( -1 );
351 
352 	return( taglen + 2 );
353 }
354 
355 #define FOUR_BYTE_LEN	5
356 
357 
358 /* the idea here is roughly this: we maintain a stack of these Seqorset
359  * structures. This is pushed when we see the beginning of a new set or
360  * sequence. It is popped when we see the end of a set or sequence.
361  * Since we don't want to malloc and free these structures all the time,
362  * we pre-allocate a small set of them within the ber element structure.
363  * thus we need to spot when we've overflowed this stack and fall back to
364  * malloc'ing instead.
365  */
366 static int
367 ber_start_seqorset( BerElement *ber, ber_tag_t tag )
368 {
369 	Seqorset	*new_sos;
370 
371 	/* can we fit into the local stack ? */
372 	if (ber->ber_sos_stack_posn < SOS_STACK_SIZE) {
373 		/* yes */
374 		new_sos = &ber->ber_sos_stack[ber->ber_sos_stack_posn];
375 	} else {
376 		/* no */
377 		if ( (new_sos = (Seqorset *)NSLBERI_MALLOC( sizeof(Seqorset)))
378 		    == NULLSEQORSET ) {
379 			return( -1 );
380 		}
381 	}
382 	ber->ber_sos_stack_posn++;
383 
384 	if ( ber->ber_sos == NULLSEQORSET )
385 		new_sos->sos_first = ber->ber_ptr;
386 	else
387 		new_sos->sos_first = ber->ber_sos->sos_ptr;
388 
389 	/* Set aside room for a 4 byte length field */
390 	new_sos->sos_ptr = new_sos->sos_first + ber_calc_taglen( tag ) + FOUR_BYTE_LEN;
391 	new_sos->sos_tag = tag;
392 
393 	new_sos->sos_next = ber->ber_sos;
394 	new_sos->sos_clen = 0;
395 
396 	ber->ber_sos = new_sos;
397     if (ber->ber_sos->sos_ptr > ber->ber_end) {
398         nslberi_ber_realloc(ber, ber->ber_sos->sos_ptr - ber->ber_end);
399     }
400 	return( 0 );
401 }
402 
403 int
404 LDAP_CALL
405 ber_start_seq( BerElement *ber, ber_tag_t tag )
406 {
407 	if ( tag == LBER_DEFAULT )
408 		tag = LBER_SEQUENCE;
409 
410 	return( ber_start_seqorset( ber, tag ) );
411 }
412 
413 int
414 LDAP_CALL
415 ber_start_set( BerElement *ber, ber_tag_t tag )
416 {
417 	if ( tag == LBER_DEFAULT )
418 		tag = LBER_SET;
419 
420 	return( ber_start_seqorset( ber, tag ) );
421 }
422 
423 static int
424 ber_put_seqorset( BerElement *ber )
425 {
426 	ber_len_t	len, netlen;
427 	int		taglen, lenlen;
428 	unsigned char	ltag = 0x80 + FOUR_BYTE_LEN - 1;
429 	Seqorset	*next;
430 	Seqorset	**sos = &ber->ber_sos;
431 
432 	/*
433 	 * If this is the toplevel sequence or set, we need to actually
434 	 * write the stuff out.  Otherwise, it's already been put in
435 	 * the appropriate buffer and will be written when the toplevel
436 	 * one is written.  In this case all we need to do is update the
437 	 * length and tag.
438 	 */
439 
440 	len = (*sos)->sos_clen;
441 	netlen = LBER_HTONL( len );
442 	if ( sizeof(ber_int_t) > 4 && len > LENMASK4 )
443 		return( -1 );
444 
445 	if ( ber->ber_options & LBER_OPT_USE_DER ) {
446 		lenlen = ber_calc_lenlen( len );
447 	} else {
448 		lenlen = FOUR_BYTE_LEN;
449 	}
450 
451 	if ( (next = (*sos)->sos_next) == NULLSEQORSET ) {
452 		/* write the tag */
453 		if ( (taglen = ber_put_tag( ber, (*sos)->sos_tag, 1 )) == -1 )
454 			return( -1 );
455 
456 		if ( ber->ber_options & LBER_OPT_USE_DER ) {
457 			/* Write the length in the minimum # of octets */
458 			if ( ber_put_len( ber, len, 1 ) == -1 )
459 				return( -1 );
460 
461 			if (lenlen != FOUR_BYTE_LEN) {
462 				/*
463 				 * We set aside FOUR_BYTE_LEN bytes for
464 				 * the length field.  Move the data if
465 				 * we don't actually need that much
466 				 */
467 				SAFEMEMCPY( (*sos)->sos_first + taglen +
468 				    lenlen, (*sos)->sos_first + taglen +
469 				    FOUR_BYTE_LEN, len );
470 			}
471 		} else {
472 			/* Fill FOUR_BYTE_LEN bytes for length field */
473 			/* one byte of length length */
474 			if ( ber_write( ber, (char *)&ltag, 1, 1 ) != 1 )
475 				return( -1 );
476 
477 			/* the length itself */
478 			if ( ber_write( ber, (char *) &netlen + sizeof(ber_int_t)
479 			    - (FOUR_BYTE_LEN - 1), FOUR_BYTE_LEN - 1, 1 )
480 			    != FOUR_BYTE_LEN - 1 )
481 				return( -1 );
482 		}
483 		/* The ber_ptr is at the set/seq start - move it to the end */
484 		ber->ber_ptr += len;
485 	} else {
486 		ber_tag_t	ntag;
487 
488 		/* the tag */
489 		taglen = ber_calc_taglen( (*sos)->sos_tag );
490 		ntag = LBER_HTONL( (*sos)->sos_tag );
491 		SAFEMEMCPY( (*sos)->sos_first, (char *) &ntag +
492 		    sizeof(ber_int_t) - taglen, taglen );
493 
494 		if ( ber->ber_options & LBER_OPT_USE_DER ) {
495 			ltag = (lenlen == 1) ? (unsigned char)len :
496                 (unsigned char) (0x80 + (lenlen - 1));
497 		}
498 
499 		/* one byte of length length */
500 		SAFEMEMCPY( (*sos)->sos_first + 1, &ltag, 1 );
501 
502 		if ( ber->ber_options & LBER_OPT_USE_DER ) {
503 			if (lenlen > 1) {
504 				/* Write the length itself */
505 				SAFEMEMCPY( (*sos)->sos_first + 2,
506 				    (char *)&netlen + sizeof(ber_uint_t) -
507 				    (lenlen - 1),
508 				    lenlen - 1 );
509 			}
510 			if (lenlen != FOUR_BYTE_LEN) {
511 				/*
512 				 * We set aside FOUR_BYTE_LEN bytes for
513 				 * the length field.  Move the data if
514 				 * we don't actually need that much
515 				 */
516 				SAFEMEMCPY( (*sos)->sos_first + taglen +
517 				    lenlen, (*sos)->sos_first + taglen +
518 				    FOUR_BYTE_LEN, len );
519 			}
520 		} else {
521 			/* the length itself */
522 			SAFEMEMCPY( (*sos)->sos_first + taglen + 1,
523 			    (char *) &netlen + sizeof(ber_int_t) -
524 			    (FOUR_BYTE_LEN - 1), FOUR_BYTE_LEN - 1 );
525 		}
526 
527 		next->sos_clen += (taglen + lenlen + len);
528 		next->sos_ptr += (taglen + lenlen + len);
529 	}
530 
531 	/* we're done with this seqorset, so free it up */
532 	/* was this one from the local stack ? */
533 	if (ber->ber_sos_stack_posn <= SOS_STACK_SIZE) {
534 		/* yes */
535 	} else {
536 		/* no */
537 		NSLBERI_FREE( (char *) (*sos) );
538 	}
539 	ber->ber_sos_stack_posn--;
540 	*sos = next;
541 
542 	return( taglen + lenlen + len );
543 }
544 
545 int
546 LDAP_CALL
547 ber_put_seq( BerElement *ber )
548 {
549 	return( ber_put_seqorset( ber ) );
550 }
551 
552 int
553 LDAP_CALL
554 ber_put_set( BerElement *ber )
555 {
556 	return( ber_put_seqorset( ber ) );
557 }
558 
559 /* VARARGS */
560 int
561 LDAP_C
562 ber_printf( BerElement *ber, const char *fmt, ... )
563 {
564 	va_list		ap;
565 	char		*s, **ss;
566 	struct berval	*bval, **bv;
567 	int		rc, i;
568 	ber_len_t	len;
569 
570 	va_start( ap, fmt );
571 
572 #ifdef LDAP_DEBUG
573 	if ( lber_debug & 64 ) {
574 		char msg[80];
575 		sprintf( msg, "ber_printf fmt (%s)\n", fmt );
576 		ber_err_print( msg );
577 	}
578 #endif
579 
580 	for ( rc = 0; *fmt && rc != -1; fmt++ ) {
581 		switch ( *fmt ) {
582 		case 'b':	/* boolean */
583 			i = va_arg( ap, int );
584 			rc = ber_put_boolean( ber, i, ber->ber_tag );
585 			break;
586 
587 		case 'i':	/* int */
588 			i = va_arg( ap, int );
589 			rc = ber_put_int( ber, (ber_int_t)i, ber->ber_tag );
590 			break;
591 
592 		case 'e':	/* enumeration */
593 			i = va_arg( ap, int );
594 			rc = ber_put_enum( ber, (ber_int_t)i, ber->ber_tag );
595 			break;
596 
597 		case 'n':	/* null */
598 			rc = ber_put_null( ber, ber->ber_tag );
599 			break;
600 
601 		case 'o':	/* octet string (non-null terminated) */
602 			s = va_arg( ap, char * );
603 			len = va_arg( ap, int );
604 			rc = ber_put_ostring( ber, s, len, ber->ber_tag );
605 			break;
606 
607 		case 'O':	/* berval octet string */
608 			if( ( bval = va_arg( ap, struct berval * ) ) == NULL )
609 				break;
610 			if( bval->bv_len == 0 ) {
611 				rc = ber_put_ostring( ber, "", 0, ber->ber_tag );
612 			} else {
613 				rc = ber_put_ostring( ber, bval->bv_val, bval->bv_len,
614 				    ber->ber_tag );
615 			}
616 			break;
617 
618 		case 's':	/* string */
619 			s = va_arg( ap, char * );
620 			rc = ber_put_string( ber, s, ber->ber_tag );
621 			break;
622 
623 		case 'B':	/* bit string */
624 			s = va_arg( ap, char * );
625 			len = va_arg( ap, int );	/* in bits */
626 			rc = ber_put_bitstring( ber, s, len, ber->ber_tag );
627 			break;
628 
629 		case 't':	/* tag for the next element */
630 			ber->ber_tag = va_arg( ap, ber_tag_t );
631 			ber->ber_usertag = 1;
632 			break;
633 
634 		case 'v':	/* vector of strings */
635 			if ( (ss = va_arg( ap, char ** )) == NULL )
636 				break;
637 			for ( i = 0; ss[i] != NULL; i++ ) {
638 				if ( (rc = ber_put_string( ber, ss[i],
639 				    ber->ber_tag )) == -1 )
640 					break;
641 			}
642 			break;
643 
644 		case 'V':	/* sequences of strings + lengths */
645 			if ( (bv = va_arg( ap, struct berval ** )) == NULL )
646 				break;
647 			for ( i = 0; bv[i] != NULL; i++ ) {
648 				if ( (rc = ber_put_ostring( ber, bv[i]->bv_val,
649 				    bv[i]->bv_len, ber->ber_tag )) == -1 )
650 					break;
651 			}
652 			break;
653 
654 		case '{':	/* begin sequence */
655 			rc = ber_start_seq( ber, ber->ber_tag );
656 			break;
657 
658 		case '}':	/* end sequence */
659 			rc = ber_put_seqorset( ber );
660 			break;
661 
662 		case '[':	/* begin set */
663 			rc = ber_start_set( ber, ber->ber_tag );
664 			break;
665 
666 		case ']':	/* end set */
667 			rc = ber_put_seqorset( ber );
668 			break;
669 
670 		default: {
671 				char msg[80];
672 				sprintf( msg, "unknown fmt %c\n", *fmt );
673 				ber_err_print( msg );
674 				rc = -1;
675 				break;
676 			}
677 		}
678 
679 		if ( ber->ber_usertag == 0 )
680 			ber->ber_tag = LBER_DEFAULT;
681 		else
682 			ber->ber_usertag = 0;
683 	}
684 
685 	va_end( ap );
686 
687 	return( rc );
688 }
689