xref: /openbsd/lib/libcrypto/asn1/a_mbstr.c (revision acf64401)
1 /* $OpenBSD: a_mbstr.c,v 1.27 2023/07/05 21:23:36 beck Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project 1999.
4  */
5 /* ====================================================================
6  * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    licensing@OpenSSL.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  *
53  * This product includes cryptographic software written by Eric Young
54  * (eay@cryptsoft.com).  This product includes software written by Tim
55  * Hudson (tjh@cryptsoft.com).
56  *
57  */
58 
59 #include <ctype.h>
60 #include <stdio.h>
61 #include <string.h>
62 
63 #include <openssl/asn1.h>
64 #include <openssl/err.h>
65 
66 #include "asn1_local.h"
67 
68 static int traverse_string(const unsigned char *p, int len, int inform,
69     int (*rfunc)(unsigned long value, void *in), void *arg);
70 static int in_utf8(unsigned long value, void *arg);
71 static int out_utf8(unsigned long value, void *arg);
72 static int type_str(unsigned long value, void *arg);
73 static int cpy_asc(unsigned long value, void *arg);
74 static int cpy_bmp(unsigned long value, void *arg);
75 static int cpy_univ(unsigned long value, void *arg);
76 static int cpy_utf8(unsigned long value, void *arg);
77 static int is_printable(unsigned long value);
78 
79 /* These functions take a string in UTF8, ASCII or multibyte form and
80  * a mask of permissible ASN1 string types. It then works out the minimal
81  * type (using the order Printable < IA5 < T61 < BMP < Universal < UTF8)
82  * and creates a string of the correct type with the supplied data.
83  * Yes this is horrible: it has to be :-(
84  * The 'ncopy' form checks minimum and maximum size limits too.
85  */
86 
87 int
ASN1_mbstring_copy(ASN1_STRING ** out,const unsigned char * in,int len,int inform,unsigned long mask)88 ASN1_mbstring_copy(ASN1_STRING **out, const unsigned char *in, int len,
89     int inform, unsigned long mask)
90 {
91 	return ASN1_mbstring_ncopy(out, in, len, inform, mask, 0, 0);
92 }
93 LCRYPTO_ALIAS(ASN1_mbstring_copy);
94 
95 int
ASN1_mbstring_ncopy(ASN1_STRING ** out,const unsigned char * in,int len,int inform,unsigned long mask,long minsize,long maxsize)96 ASN1_mbstring_ncopy(ASN1_STRING **out, const unsigned char *in, int len,
97     int inform, unsigned long mask, long minsize, long maxsize)
98 {
99 	int str_type;
100 	int ret;
101 	char free_out;
102 	int outform, outlen = 0;
103 	ASN1_STRING *dest;
104 	unsigned char *p;
105 	int nchar;
106 	int (*cpyfunc)(unsigned long, void *) = NULL;
107 
108 	if (len < 0)
109 		len = strlen((const char *)in);
110 	if (!mask)
111 		mask = DIRSTRING_TYPE;
112 
113 	/* First do a string check and work out the number of characters */
114 	switch (inform) {
115 	case MBSTRING_BMP:
116 		if (len & 1) {
117 			ASN1error(ASN1_R_INVALID_BMPSTRING_LENGTH);
118 			return -1;
119 		}
120 		nchar = len >> 1;
121 		break;
122 
123 	case MBSTRING_UNIV:
124 		if (len & 3) {
125 			ASN1error(ASN1_R_INVALID_UNIVERSALSTRING_LENGTH);
126 			return -1;
127 		}
128 		nchar = len >> 2;
129 		break;
130 
131 	case MBSTRING_UTF8:
132 		nchar = 0;
133 		/* This counts the characters and does utf8 syntax checking */
134 		ret = traverse_string(in, len, MBSTRING_UTF8, in_utf8, &nchar);
135 		if (ret < 0) {
136 			ASN1error(ASN1_R_INVALID_UTF8STRING);
137 			return -1;
138 		}
139 		break;
140 
141 	case MBSTRING_ASC:
142 		nchar = len;
143 		break;
144 
145 	default:
146 		ASN1error(ASN1_R_UNKNOWN_FORMAT);
147 		return -1;
148 	}
149 
150 	if ((minsize > 0) && (nchar < minsize)) {
151 		ASN1error(ASN1_R_STRING_TOO_SHORT);
152 		ERR_asprintf_error_data("minsize=%ld", minsize);
153 		return -1;
154 	}
155 
156 	if ((maxsize > 0) && (nchar > maxsize)) {
157 		ASN1error(ASN1_R_STRING_TOO_LONG);
158 		ERR_asprintf_error_data("maxsize=%ld", maxsize);
159 		return -1;
160 	}
161 
162 	/* Now work out minimal type (if any) */
163 	if (traverse_string(in, len, inform, type_str, &mask) < 0) {
164 		ASN1error(ASN1_R_ILLEGAL_CHARACTERS);
165 		return -1;
166 	}
167 
168 
169 	/* Now work out output format and string type */
170 	outform = MBSTRING_ASC;
171 	if (mask & B_ASN1_PRINTABLESTRING)
172 		str_type = V_ASN1_PRINTABLESTRING;
173 	else if (mask & B_ASN1_IA5STRING)
174 		str_type = V_ASN1_IA5STRING;
175 	else if (mask & B_ASN1_T61STRING)
176 		str_type = V_ASN1_T61STRING;
177 	else if (mask & B_ASN1_BMPSTRING) {
178 		str_type = V_ASN1_BMPSTRING;
179 		outform = MBSTRING_BMP;
180 	} else if (mask & B_ASN1_UNIVERSALSTRING) {
181 		str_type = V_ASN1_UNIVERSALSTRING;
182 		outform = MBSTRING_UNIV;
183 	} else {
184 		str_type = V_ASN1_UTF8STRING;
185 		outform = MBSTRING_UTF8;
186 	}
187 	if (!out)
188 		return str_type;
189 	if (*out) {
190 		free_out = 0;
191 		dest = *out;
192 		if (dest->data) {
193 			dest->length = 0;
194 			free(dest->data);
195 			dest->data = NULL;
196 		}
197 		dest->type = str_type;
198 	} else {
199 		free_out = 1;
200 		dest = ASN1_STRING_type_new(str_type);
201 		if (!dest) {
202 			ASN1error(ERR_R_MALLOC_FAILURE);
203 			return -1;
204 		}
205 		*out = dest;
206 	}
207 	/* If both the same type just copy across */
208 	if (inform == outform) {
209 		if (!ASN1_STRING_set(dest, in, len)) {
210 			ASN1error(ERR_R_MALLOC_FAILURE);
211 			goto err;
212 		}
213 		return str_type;
214 	}
215 
216 	/* Work out how much space the destination will need */
217 	switch (outform) {
218 	case MBSTRING_ASC:
219 		outlen = nchar;
220 		cpyfunc = cpy_asc;
221 		break;
222 
223 	case MBSTRING_BMP:
224 		outlen = nchar << 1;
225 		cpyfunc = cpy_bmp;
226 		break;
227 
228 	case MBSTRING_UNIV:
229 		outlen = nchar << 2;
230 		cpyfunc = cpy_univ;
231 		break;
232 
233 	case MBSTRING_UTF8:
234 		outlen = 0;
235 		if (traverse_string(in, len, inform, out_utf8, &outlen) < 0) {
236 			ASN1error(ASN1_R_ILLEGAL_CHARACTERS);
237 			goto err;
238 		}
239 		cpyfunc = cpy_utf8;
240 		break;
241 	}
242 	if (!(p = malloc(outlen + 1))) {
243 		ASN1error(ERR_R_MALLOC_FAILURE);
244 		goto err;
245 	}
246 	dest->length = outlen;
247 	dest->data = p;
248 	p[outlen] = 0;
249 	traverse_string(in, len, inform, cpyfunc, &p);
250 	return str_type;
251 
252  err:
253 	if (free_out) {
254 		ASN1_STRING_free(dest);
255 		*out = NULL;
256 	}
257 	return -1;
258 }
259 LCRYPTO_ALIAS(ASN1_mbstring_ncopy);
260 
261 /* This function traverses a string and passes the value of each character
262  * to an optional function along with a void * argument.
263  */
264 
265 static int
traverse_string(const unsigned char * p,int len,int inform,int (* rfunc)(unsigned long value,void * in),void * arg)266 traverse_string(const unsigned char *p, int len, int inform,
267     int (*rfunc)(unsigned long value, void *in), void *arg)
268 {
269 	unsigned long value;
270 	int ret;
271 
272 	while (len) {
273 		switch (inform) {
274 		case MBSTRING_ASC:
275 			value = *p++;
276 			len--;
277 			break;
278 		case MBSTRING_BMP:
279 			value = *p++ << 8;
280 			value |= *p++;
281 			/* BMP is explicitly defined to not support surrogates */
282 			if (UNICODE_IS_SURROGATE(value))
283 				return -1;
284 			len -= 2;
285 			break;
286 		case MBSTRING_UNIV:
287 			value = (unsigned long)*p++ << 24;
288 			value |= *p++ << 16;
289 			value |= *p++ << 8;
290 			value |= *p++;
291 			if (value > UNICODE_MAX || UNICODE_IS_SURROGATE(value))
292 				return -1;
293 			len -= 4;
294 			break;
295 		default:
296 			ret = UTF8_getc(p, len, &value);
297 			if (ret < 0)
298 				return -1;
299 			len -= ret;
300 			p += ret;
301 			break;
302 		}
303 		if (rfunc) {
304 			ret = rfunc(value, arg);
305 			if (ret <= 0)
306 				return ret;
307 		}
308 	}
309 	return 1;
310 }
311 
312 /* Various utility functions for traverse_string */
313 
314 /* Just count number of characters */
315 
316 static int
in_utf8(unsigned long value,void * arg)317 in_utf8(unsigned long value, void *arg)
318 {
319 	int *nchar;
320 
321 	nchar = arg;
322 	(*nchar)++;
323 	return 1;
324 }
325 
326 /* Determine size of output as a UTF8 String */
327 
328 static int
out_utf8(unsigned long value,void * arg)329 out_utf8(unsigned long value, void *arg)
330 {
331 	int *outlen;
332 	int ret;
333 
334 	outlen = arg;
335 	ret = UTF8_putc(NULL, -1, value);
336 	if (ret < 0)
337 		return ret;
338 	*outlen += ret;
339 	return 1;
340 }
341 
342 /* Determine the "type" of a string: check each character against a
343  * supplied "mask".
344  */
345 
346 static int
type_str(unsigned long value,void * arg)347 type_str(unsigned long value, void *arg)
348 {
349 	unsigned long types;
350 
351 	types = *((unsigned long *)arg);
352 	if ((types & B_ASN1_PRINTABLESTRING) && !is_printable(value))
353 		types &= ~B_ASN1_PRINTABLESTRING;
354 	if ((types & B_ASN1_IA5STRING) && (value > 127))
355 		types &= ~B_ASN1_IA5STRING;
356 	if ((types & B_ASN1_T61STRING) && (value > 0xff))
357 		types &= ~B_ASN1_T61STRING;
358 	if ((types & B_ASN1_BMPSTRING) && (value > 0xffff))
359 		types &= ~B_ASN1_BMPSTRING;
360 	if (!types)
361 		return -1;
362 	*((unsigned long *)arg) = types;
363 	return 1;
364 }
365 
366 /* Copy one byte per character ASCII like strings */
367 
368 static int
cpy_asc(unsigned long value,void * arg)369 cpy_asc(unsigned long value, void *arg)
370 {
371 	unsigned char **p, *q;
372 
373 	p = arg;
374 	q = *p;
375 	*q = value;
376 	(*p)++;
377 	return 1;
378 }
379 
380 /* Copy two byte per character BMPStrings */
381 
382 static int
cpy_bmp(unsigned long value,void * arg)383 cpy_bmp(unsigned long value, void *arg)
384 {
385 	unsigned char **p, *q;
386 
387 	p = arg;
388 	q = *p;
389 	*q++ = (value >> 8) & 0xff;
390 	*q = value & 0xff;
391 	*p += 2;
392 	return 1;
393 }
394 
395 /* Copy four byte per character UniversalStrings */
396 
397 static int
cpy_univ(unsigned long value,void * arg)398 cpy_univ(unsigned long value, void *arg)
399 {
400 	unsigned char **p, *q;
401 
402 	p = arg;
403 	q = *p;
404 	*q++ = (value >> 24) & 0xff;
405 	*q++ = (value >> 16) & 0xff;
406 	*q++ = (value >> 8) & 0xff;
407 	*q = value & 0xff;
408 	*p += 4;
409 	return 1;
410 }
411 
412 /* Copy to a UTF8String */
413 
414 static int
cpy_utf8(unsigned long value,void * arg)415 cpy_utf8(unsigned long value, void *arg)
416 {
417 	unsigned char **p;
418 
419 	int ret;
420 	p = arg;
421 	/* We already know there is enough room so pass 0xff as the length */
422 	ret = UTF8_putc(*p, 0xff, value);
423 	*p += ret;
424 	return 1;
425 }
426 
427 /* Return 1 if the character is permitted in a PrintableString */
428 static int
is_printable(unsigned long value)429 is_printable(unsigned long value)
430 {
431 	int ch;
432 
433 	if (value > 0x7f)
434 		return 0;
435 	ch = (int)value;
436 
437 	/* Note: we can't use 'isalnum' because certain accented
438 	 * characters may count as alphanumeric in some environments.
439 	 */
440 	if ((ch >= 'a') && (ch <= 'z'))
441 		return 1;
442 	if ((ch >= 'A') && (ch <= 'Z'))
443 		return 1;
444 	if ((ch >= '0') && (ch <= '9'))
445 		return 1;
446 	if ((ch == ' ') || strchr("'()+,-./:=?", ch))
447 		return 1;
448 	return 0;
449 }
450