xref: /openssl/crypto/asn1/a_strex.c (revision 7ed6de99)
1 /*
2  * Copyright 2000-2024 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <stdio.h>
11 #include <string.h>
12 #include "internal/cryptlib.h"
13 #include "internal/sizes.h"
14 #include "crypto/asn1.h"
15 #include <openssl/crypto.h>
16 #include <openssl/x509.h>
17 #include <openssl/asn1.h>
18 
19 #include "charmap.h"
20 
21 /*
22  * ASN1_STRING_print_ex() and X509_NAME_print_ex(). Enhanced string and name
23  * printing routines handling multibyte characters, RFC2253 and a host of
24  * other options.
25  */
26 
27 #define CHARTYPE_BS_ESC         (ASN1_STRFLGS_ESC_2253 | CHARTYPE_FIRST_ESC_2253 | CHARTYPE_LAST_ESC_2253)
28 
29 #define ESC_FLAGS (ASN1_STRFLGS_ESC_2253 | \
30                   ASN1_STRFLGS_ESC_2254 | \
31                   ASN1_STRFLGS_ESC_QUOTE | \
32                   ASN1_STRFLGS_ESC_CTRL | \
33                   ASN1_STRFLGS_ESC_MSB)
34 
35 /*
36  * Three IO functions for sending data to memory, a BIO and a FILE
37  * pointer.
38  */
send_bio_chars(void * arg,const void * buf,int len)39 static int send_bio_chars(void *arg, const void *buf, int len)
40 {
41     if (!arg)
42         return 1;
43     if (BIO_write(arg, buf, len) != len)
44         return 0;
45     return 1;
46 }
47 
48 #ifndef OPENSSL_NO_STDIO
send_fp_chars(void * arg,const void * buf,int len)49 static int send_fp_chars(void *arg, const void *buf, int len)
50 {
51     if (!arg)
52         return 1;
53     if (fwrite(buf, 1, len, arg) != (unsigned int)len)
54         return 0;
55     return 1;
56 }
57 #endif
58 
59 typedef int char_io (void *arg, const void *buf, int len);
60 
61 /*
62  * This function handles display of strings, one character at a time. It is
63  * passed an unsigned long for each character because it could come from 2 or
64  * even 4 byte forms.
65  */
66 
do_esc_char(unsigned long c,unsigned short flags,char * do_quotes,char_io * io_ch,void * arg)67 static int do_esc_char(unsigned long c, unsigned short flags, char *do_quotes,
68                        char_io *io_ch, void *arg)
69 {
70     unsigned short chflgs;
71     unsigned char chtmp;
72     char tmphex[HEX_SIZE(long) + 3];
73 
74     if (c > 0xffffffffL)
75         return -1;
76     if (c > 0xffff) {
77         BIO_snprintf(tmphex, sizeof(tmphex), "\\W%08lX", c);
78         if (!io_ch(arg, tmphex, 10))
79             return -1;
80         return 10;
81     }
82     if (c > 0xff) {
83         BIO_snprintf(tmphex, sizeof(tmphex), "\\U%04lX", c);
84         if (!io_ch(arg, tmphex, 6))
85             return -1;
86         return 6;
87     }
88     chtmp = (unsigned char)c;
89     if (chtmp > 0x7f)
90         chflgs = flags & ASN1_STRFLGS_ESC_MSB;
91     else
92         chflgs = char_type[chtmp] & flags;
93     if (chflgs & CHARTYPE_BS_ESC) {
94         /* If we don't escape with quotes, signal we need quotes */
95         if (chflgs & ASN1_STRFLGS_ESC_QUOTE) {
96             if (do_quotes)
97                 *do_quotes = 1;
98             if (!io_ch(arg, &chtmp, 1))
99                 return -1;
100             return 1;
101         }
102         if (!io_ch(arg, "\\", 1))
103             return -1;
104         if (!io_ch(arg, &chtmp, 1))
105             return -1;
106         return 2;
107     }
108     if (chflgs & (ASN1_STRFLGS_ESC_CTRL
109                   | ASN1_STRFLGS_ESC_MSB
110                   | ASN1_STRFLGS_ESC_2254)) {
111         BIO_snprintf(tmphex, 11, "\\%02X", chtmp);
112         if (!io_ch(arg, tmphex, 3))
113             return -1;
114         return 3;
115     }
116     /*
117      * If we get this far and do any escaping at all must escape the escape
118      * character itself: backslash.
119      */
120     if (chtmp == '\\' && (flags & ESC_FLAGS)) {
121         if (!io_ch(arg, "\\\\", 2))
122             return -1;
123         return 2;
124     }
125     if (!io_ch(arg, &chtmp, 1))
126         return -1;
127     return 1;
128 }
129 
130 #define BUF_TYPE_WIDTH_MASK     0x7
131 #define BUF_TYPE_CONVUTF8       0x8
132 
133 /*
134  * This function sends each character in a buffer to do_esc_char(). It
135  * interprets the content formats and converts to or from UTF8 as
136  * appropriate.
137  */
138 
do_buf(unsigned char * buf,int buflen,int type,unsigned short flags,char * quotes,char_io * io_ch,void * arg)139 static int do_buf(unsigned char *buf, int buflen,
140                   int type, unsigned short flags, char *quotes, char_io *io_ch,
141                   void *arg)
142 {
143     int i, outlen, len, charwidth;
144     unsigned short orflags;
145     unsigned char *p, *q;
146     unsigned long c;
147 
148     p = buf;
149     q = buf + buflen;
150     outlen = 0;
151     charwidth = type & BUF_TYPE_WIDTH_MASK;
152 
153     switch (charwidth) {
154     case 4:
155         if (buflen & 3) {
156             ERR_raise(ERR_LIB_ASN1, ASN1_R_INVALID_UNIVERSALSTRING_LENGTH);
157             return -1;
158         }
159         break;
160     case 2:
161         if (buflen & 1) {
162             ERR_raise(ERR_LIB_ASN1, ASN1_R_INVALID_BMPSTRING_LENGTH);
163             return -1;
164         }
165         break;
166     default:
167         break;
168     }
169 
170     while (p != q) {
171         if (p == buf && flags & ASN1_STRFLGS_ESC_2253)
172             orflags = CHARTYPE_FIRST_ESC_2253;
173         else
174             orflags = 0;
175 
176         switch (charwidth) {
177         case 4:
178             c = ((unsigned long)*p++) << 24;
179             c |= ((unsigned long)*p++) << 16;
180             c |= ((unsigned long)*p++) << 8;
181             c |= *p++;
182             break;
183 
184         case 2:
185             c = ((unsigned long)*p++) << 8;
186             c |= *p++;
187             break;
188 
189         case 1:
190             c = *p++;
191             break;
192 
193         case 0:
194             i = UTF8_getc(p, buflen, &c);
195             if (i < 0)
196                 return -1;      /* Invalid UTF8String */
197             buflen -= i;
198             p += i;
199             break;
200         default:
201             return -1;          /* invalid width */
202         }
203         if (p == q && flags & ASN1_STRFLGS_ESC_2253)
204             orflags = CHARTYPE_LAST_ESC_2253;
205         if (type & BUF_TYPE_CONVUTF8) {
206             unsigned char utfbuf[6];
207             int utflen;
208             utflen = UTF8_putc(utfbuf, sizeof(utfbuf), c);
209             for (i = 0; i < utflen; i++) {
210                 /*
211                  * We don't need to worry about setting orflags correctly
212                  * because if utflen==1 its value will be correct anyway
213                  * otherwise each character will be > 0x7f and so the
214                  * character will never be escaped on first and last.
215                  */
216                 len = do_esc_char(utfbuf[i], flags | orflags, quotes,
217                                   io_ch, arg);
218                 if (len < 0)
219                     return -1;
220                 outlen += len;
221             }
222         } else {
223             len = do_esc_char(c, flags | orflags, quotes,
224                               io_ch, arg);
225             if (len < 0)
226                 return -1;
227             outlen += len;
228         }
229     }
230     return outlen;
231 }
232 
233 /* This function hex dumps a buffer of characters */
234 
do_hex_dump(char_io * io_ch,void * arg,unsigned char * buf,int buflen)235 static int do_hex_dump(char_io *io_ch, void *arg, unsigned char *buf,
236                        int buflen)
237 {
238     unsigned char *p, *q;
239     char hextmp[2];
240 
241     if (arg) {
242         p = buf;
243         q = buf + buflen;
244         while (p != q) {
245             ossl_to_hex(hextmp, *p);
246             if (!io_ch(arg, hextmp, 2))
247                 return -1;
248             p++;
249         }
250     }
251     return buflen << 1;
252 }
253 
254 /*
255  * "dump" a string. This is done when the type is unknown, or the flags
256  * request it. We can either dump the content octets or the entire DER
257  * encoding. This uses the RFC2253 #01234 format.
258  */
259 
do_dump(unsigned long lflags,char_io * io_ch,void * arg,const ASN1_STRING * str)260 static int do_dump(unsigned long lflags, char_io *io_ch, void *arg,
261                    const ASN1_STRING *str)
262 {
263     /*
264      * Placing the ASN1_STRING in a temp ASN1_TYPE allows the DER encoding to
265      * readily obtained
266      */
267     ASN1_TYPE t;
268     unsigned char *der_buf, *p;
269     int outlen, der_len;
270 
271     if (!io_ch(arg, "#", 1))
272         return -1;
273     /* If we don't dump DER encoding just dump content octets */
274     if (!(lflags & ASN1_STRFLGS_DUMP_DER)) {
275         outlen = do_hex_dump(io_ch, arg, str->data, str->length);
276         if (outlen < 0)
277             return -1;
278         return outlen + 1;
279     }
280     t.type = str->type;
281     t.value.ptr = (char *)str;
282     der_len = i2d_ASN1_TYPE(&t, NULL);
283     if (der_len <= 0)
284         return -1;
285     if ((der_buf = OPENSSL_malloc(der_len)) == NULL)
286         return -1;
287     p = der_buf;
288     i2d_ASN1_TYPE(&t, &p);
289     outlen = do_hex_dump(io_ch, arg, der_buf, der_len);
290     OPENSSL_free(der_buf);
291     if (outlen < 0)
292         return -1;
293     return outlen + 1;
294 }
295 
296 /*
297  * Lookup table to convert tags to character widths, 0 = UTF8 encoded, -1 is
298  * used for non string types otherwise it is the number of bytes per
299  * character
300  */
301 
302 static const signed char tag2nbyte[] = {
303     -1, -1, -1, -1, -1,         /* 0-4 */
304     -1, -1, -1, -1, -1,         /* 5-9 */
305     -1, -1,                     /* 10-11 */
306      0,                         /* 12 V_ASN1_UTF8STRING */
307     -1, -1, -1, -1, -1,         /* 13-17 */
308      1,                         /* 18 V_ASN1_NUMERICSTRING */
309      1,                         /* 19 V_ASN1_PRINTABLESTRING */
310      1,                         /* 20 V_ASN1_T61STRING */
311     -1,                         /* 21 */
312      1,                         /* 22 V_ASN1_IA5STRING */
313      1,                         /* 23 V_ASN1_UTCTIME */
314      1,                         /* 24 V_ASN1_GENERALIZEDTIME */
315     -1,                         /* 25 */
316      1,                         /* 26 V_ASN1_ISO64STRING */
317     -1,                         /* 27 */
318      4,                         /* 28 V_ASN1_UNIVERSALSTRING */
319     -1,                         /* 29 */
320      2                          /* 30 V_ASN1_BMPSTRING */
321 };
322 
323 /*
324  * This is the main function, print out an ASN1_STRING taking note of various
325  * escape and display options. Returns number of characters written or -1 if
326  * an error occurred.
327  */
328 
do_print_ex(char_io * io_ch,void * arg,unsigned long lflags,const ASN1_STRING * str)329 static int do_print_ex(char_io *io_ch, void *arg, unsigned long lflags,
330                        const ASN1_STRING *str)
331 {
332     int outlen, len;
333     int type;
334     char quotes;
335     unsigned short flags;
336     quotes = 0;
337     /* Keep a copy of escape flags */
338     flags = (unsigned short)(lflags & ESC_FLAGS);
339 
340     type = str->type;
341 
342     outlen = 0;
343 
344     if (lflags & ASN1_STRFLGS_SHOW_TYPE) {
345         const char *tagname;
346 
347         tagname = ASN1_tag2str(type);
348         /* We can directly cast here as tagname will never be too large. */
349         outlen += (int)strlen(tagname);
350         if (!io_ch(arg, tagname, outlen) || !io_ch(arg, ":", 1))
351             return -1;
352         outlen++;
353     }
354 
355     /* Decide what to do with type, either dump content or display it */
356 
357     /* Dump everything */
358     if (lflags & ASN1_STRFLGS_DUMP_ALL)
359         type = -1;
360     /* Ignore the string type */
361     else if (lflags & ASN1_STRFLGS_IGNORE_TYPE)
362         type = 1;
363     else {
364         /* Else determine width based on type */
365         if ((type > 0) && (type < 31))
366             type = tag2nbyte[type];
367         else
368             type = -1;
369         if ((type == -1) && !(lflags & ASN1_STRFLGS_DUMP_UNKNOWN))
370             type = 1;
371     }
372 
373     if (type == -1) {
374         len = do_dump(lflags, io_ch, arg, str);
375         if (len < 0 || len > INT_MAX - outlen)
376             return -1;
377         outlen += len;
378         return outlen;
379     }
380 
381     if (lflags & ASN1_STRFLGS_UTF8_CONVERT) {
382         /*
383          * Note: if string is UTF8 and we want to convert to UTF8 then we
384          * just interpret it as 1 byte per character to avoid converting
385          * twice.
386          */
387         if (!type)
388             type = 1;
389         else
390             type |= BUF_TYPE_CONVUTF8;
391     }
392 
393     len = do_buf(str->data, str->length, type, flags, &quotes, io_ch, NULL);
394     if (len < 0 || len > INT_MAX - 2 - outlen)
395         return -1;
396     outlen += len;
397     if (quotes)
398         outlen += 2;
399     if (!arg)
400         return outlen;
401     if (quotes && !io_ch(arg, "\"", 1))
402         return -1;
403     if (do_buf(str->data, str->length, type, flags, NULL, io_ch, arg) < 0)
404         return -1;
405     if (quotes && !io_ch(arg, "\"", 1))
406         return -1;
407     return outlen;
408 }
409 
410 /* Used for line indenting: print 'indent' spaces */
411 
do_indent(char_io * io_ch,void * arg,int indent)412 static int do_indent(char_io *io_ch, void *arg, int indent)
413 {
414     int i;
415     for (i = 0; i < indent; i++)
416         if (!io_ch(arg, " ", 1))
417             return 0;
418     return 1;
419 }
420 
421 #define FN_WIDTH_LN     25
422 #define FN_WIDTH_SN     10
423 
do_name_ex(char_io * io_ch,void * arg,const X509_NAME * n,int indent,unsigned long flags)424 static int do_name_ex(char_io *io_ch, void *arg, const X509_NAME *n,
425                       int indent, unsigned long flags)
426 {
427     int i, prev = -1, orflags, cnt;
428     int fn_opt, fn_nid;
429     ASN1_OBJECT *fn;
430     const ASN1_STRING *val;
431     const X509_NAME_ENTRY *ent;
432     char objtmp[80];
433     const char *objbuf;
434     int outlen, len;
435     char *sep_dn, *sep_mv, *sep_eq;
436     int sep_dn_len, sep_mv_len, sep_eq_len;
437     if (indent < 0)
438         indent = 0;
439     outlen = indent;
440     if (!do_indent(io_ch, arg, indent))
441         return -1;
442     switch (flags & XN_FLAG_SEP_MASK) {
443     case XN_FLAG_SEP_MULTILINE:
444         sep_dn = "\n";
445         sep_dn_len = 1;
446         sep_mv = " + ";
447         sep_mv_len = 3;
448         break;
449 
450     case XN_FLAG_SEP_COMMA_PLUS:
451         sep_dn = ",";
452         sep_dn_len = 1;
453         sep_mv = "+";
454         sep_mv_len = 1;
455         indent = 0;
456         break;
457 
458     case XN_FLAG_SEP_CPLUS_SPC:
459         sep_dn = ", ";
460         sep_dn_len = 2;
461         sep_mv = " + ";
462         sep_mv_len = 3;
463         indent = 0;
464         break;
465 
466     case XN_FLAG_SEP_SPLUS_SPC:
467         sep_dn = "; ";
468         sep_dn_len = 2;
469         sep_mv = " + ";
470         sep_mv_len = 3;
471         indent = 0;
472         break;
473 
474     default:
475         return -1;
476     }
477 
478     if (flags & XN_FLAG_SPC_EQ) {
479         sep_eq = " = ";
480         sep_eq_len = 3;
481     } else {
482         sep_eq = "=";
483         sep_eq_len = 1;
484     }
485 
486     fn_opt = flags & XN_FLAG_FN_MASK;
487 
488     cnt = X509_NAME_entry_count(n);
489     for (i = 0; i < cnt; i++) {
490         if (flags & XN_FLAG_DN_REV)
491             ent = X509_NAME_get_entry(n, cnt - i - 1);
492         else
493             ent = X509_NAME_get_entry(n, i);
494         if (prev != -1) {
495             if (prev == X509_NAME_ENTRY_set(ent)) {
496                 if (!io_ch(arg, sep_mv, sep_mv_len))
497                     return -1;
498                 outlen += sep_mv_len;
499             } else {
500                 if (!io_ch(arg, sep_dn, sep_dn_len))
501                     return -1;
502                 outlen += sep_dn_len;
503                 if (!do_indent(io_ch, arg, indent))
504                     return -1;
505                 outlen += indent;
506             }
507         }
508         prev = X509_NAME_ENTRY_set(ent);
509         fn = X509_NAME_ENTRY_get_object(ent);
510         val = X509_NAME_ENTRY_get_data(ent);
511         fn_nid = OBJ_obj2nid(fn);
512         if (fn_opt != XN_FLAG_FN_NONE) {
513             int objlen, fld_len;
514             if ((fn_opt == XN_FLAG_FN_OID) || (fn_nid == NID_undef)) {
515                 OBJ_obj2txt(objtmp, sizeof(objtmp), fn, 1);
516                 fld_len = 0;    /* XXX: what should this be? */
517                 objbuf = objtmp;
518             } else {
519                 if (fn_opt == XN_FLAG_FN_SN) {
520                     fld_len = FN_WIDTH_SN;
521                     objbuf = OBJ_nid2sn(fn_nid);
522                 } else if (fn_opt == XN_FLAG_FN_LN) {
523                     fld_len = FN_WIDTH_LN;
524                     objbuf = OBJ_nid2ln(fn_nid);
525                 } else {
526                     fld_len = 0; /* XXX: what should this be? */
527                     objbuf = "";
528                 }
529             }
530             objlen = strlen(objbuf);
531             if (!io_ch(arg, objbuf, objlen))
532                 return -1;
533             if ((objlen < fld_len) && (flags & XN_FLAG_FN_ALIGN)) {
534                 if (!do_indent(io_ch, arg, fld_len - objlen))
535                     return -1;
536                 outlen += fld_len - objlen;
537             }
538             if (!io_ch(arg, sep_eq, sep_eq_len))
539                 return -1;
540             outlen += objlen + sep_eq_len;
541         }
542         /*
543          * If the field name is unknown then fix up the DER dump flag. We
544          * might want to limit this further so it will DER dump on anything
545          * other than a few 'standard' fields.
546          */
547         if ((fn_nid == NID_undef) && (flags & XN_FLAG_DUMP_UNKNOWN_FIELDS))
548             orflags = ASN1_STRFLGS_DUMP_ALL;
549         else
550             orflags = 0;
551 
552         len = do_print_ex(io_ch, arg, flags | orflags, val);
553         if (len < 0)
554             return -1;
555         outlen += len;
556     }
557     return outlen;
558 }
559 
560 /* Wrappers round the main functions */
561 
X509_NAME_print_ex(BIO * out,const X509_NAME * nm,int indent,unsigned long flags)562 int X509_NAME_print_ex(BIO *out, const X509_NAME *nm, int indent,
563                        unsigned long flags)
564 {
565     if (flags == XN_FLAG_COMPAT)
566         return X509_NAME_print(out, nm, indent);
567     return do_name_ex(send_bio_chars, out, nm, indent, flags);
568 }
569 
570 #ifndef OPENSSL_NO_STDIO
X509_NAME_print_ex_fp(FILE * fp,const X509_NAME * nm,int indent,unsigned long flags)571 int X509_NAME_print_ex_fp(FILE *fp, const X509_NAME *nm, int indent,
572                           unsigned long flags)
573 {
574     if (flags == XN_FLAG_COMPAT) {
575         BIO *btmp;
576         int ret;
577         btmp = BIO_new_fp(fp, BIO_NOCLOSE);
578         if (!btmp)
579             return -1;
580         ret = X509_NAME_print(btmp, nm, indent);
581         BIO_free(btmp);
582         return ret;
583     }
584     return do_name_ex(send_fp_chars, fp, nm, indent, flags);
585 }
586 #endif
587 
ASN1_STRING_print_ex(BIO * out,const ASN1_STRING * str,unsigned long flags)588 int ASN1_STRING_print_ex(BIO *out, const ASN1_STRING *str, unsigned long flags)
589 {
590     return do_print_ex(send_bio_chars, out, flags, str);
591 }
592 
593 #ifndef OPENSSL_NO_STDIO
ASN1_STRING_print_ex_fp(FILE * fp,const ASN1_STRING * str,unsigned long flags)594 int ASN1_STRING_print_ex_fp(FILE *fp, const ASN1_STRING *str, unsigned long flags)
595 {
596     return do_print_ex(send_fp_chars, fp, flags, str);
597 }
598 #endif
599 
600 /*
601  * Utility function: convert any string type to UTF8, returns number of bytes
602  * in output string or a negative error code
603  */
604 
ASN1_STRING_to_UTF8(unsigned char ** out,const ASN1_STRING * in)605 int ASN1_STRING_to_UTF8(unsigned char **out, const ASN1_STRING *in)
606 {
607     ASN1_STRING stmp, *str = &stmp;
608     int mbflag, type, ret;
609     if (!in)
610         return -1;
611     type = in->type;
612     if ((type < 0) || (type > 30))
613         return -1;
614     mbflag = tag2nbyte[type];
615     if (mbflag == -1)
616         return -1;
617     mbflag |= MBSTRING_FLAG;
618     stmp.data = NULL;
619     stmp.length = 0;
620     stmp.flags = 0;
621     ret =
622         ASN1_mbstring_copy(&str, in->data, in->length, mbflag,
623                            B_ASN1_UTF8STRING);
624     if (ret < 0)
625         return ret;
626     *out = stmp.data;
627     return stmp.length;
628 }
629